Patent Publication Number: US-6703624-B2

Title: Multi-beam exposure apparatus using a multi-axis electron lens, electron lens convergencing a plurality of electron beam and fabrication method of a semiconductor device

Description:
This is a counterpart application of a Japanese patent applications 2000-102619, filed on Apr. 4, 2000, 2000-251885, filed on Aug. 23, 2000, and 2000-342660, filed on Oct. 3, 2000, the contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a multi-electron-beam exposure apparatus, a multi-axis electron lens, a fabrication method of the multi-axis electron lens and a fabrication method of a semiconductor device. 
     2. Description of the Related Art 
     Conventionally, it is known an electron-beam exposure apparatus capable of exposing a wafer with a plurality of electron beams in order to form a semi-conductor device. For example, an electrons-beam exposure apparatus including an electron lens having a pair of magnetic plates placed in parallel relationship with each other is disclosed in U.S. Pat. No. 3,715,580 or in U.S. Pat. No. 4,209,702. The pair of magnetic plates has a plurality of through holes at places corresponding to each other for respectively having the plurality of electron beams pass therethrough in order for focusing images. 
     As semi-conductor devices are becoming more and more minute structures, exposure apparatuses for forming lines of the semi-conductor devices are required to have high accuracy in focusing images. Therefore, it is highly expected that an electron-beam exposure apparatuses capable of exposing a plurality of electron beams for forming patterns of lines of the semi-conductor devices be commercially produced. In order to produce quantity of semi-conductor devices by such the electron-beam exposure apparatus, preferably, the focusing points of the plurality of electron beams should be adjusted on the wafer become. 
     The conventional electron beam exposure apparatus disclosed in above patents corrects the focusing point of the electron beams by using exciting coils provided between the pair of magnetic plates. However, as for the conventional electron beam exposure apparatus, in case that the magnetic fields formed in each of the plurality of through holes are dispersed largely, it is difficult to correct the focusing point of the electron beams uniformly. Especially, as the size of the wafer becomes lager, the electric field strength formed in the through holes at the edge of the electron lens becomes more different from that at the center of the electron lens. 
     Therefore, as for the conventional electron beam exposure apparatus, the focusing points of the plurality of electron beams cannot be adjusted on the wafer. Thus, this type of electron-beam exposure apparatus cannot show accuracy in focusing the images. This fact prevents the electron-beam exposure apparatus exposing a plurality of electron beams from commercially produced. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of the present invention to provide a multi-beam exposure apparatus using a multi-axis electron lens, a multi-axis electron lens and a fabrication method of a semiconductor device, which is capable of overcoming the above drawbacks accompanying the conventional art. The above and other objects can be achieved by combinations described in the independent claims. The dependent claims define further advantageous and exemplary combinations of the present invention. 
     According to the first aspect of the present invention, an electron beam exposure apparatus for exposing a wafer with a plurality of electron beams, comprising a multi-axis electron lens having a plurality of lens openings operable to converge said plurality of electron beams independently of each other by allowing said plurality of electron beams to pass therethrough, respectively, said plurality of lens openings having different shapes. 
     The multi-axis electron lens may include a plurality of magnetic conductive members having a plurality of openings arranged to be substantially parallel to each other, said plurality of openings forming said lens openings. 
     The magnetic conductive members may include said openings having different sizes. 
     At least one of said plurality of magnetic conductive members may include cut portions provided in outer peripheries of said openings. 
     The cut portions may have different sizes. 
     At least one of said magnetic conductive members may include a magnetic conductive projection provided on a surface thereof between a predetermined one of said openings and another opening adjacent to said predetermined opening, said magnetic conductive projection projecting from said surface of said at least one of said magnetic conductive members. 
     The electron beam exposure apparatus may further comprise a lens-intensity adjuster including: a substrate provided to be substantially parallel to said multi-axis electron lens; and a lens-intensity adjusting unit, provided on said substrate, operable to adjust the lens intensity of said multi-axis electron lens applied to said electron beams passing through said lens openings, respectively. 
     The lens-intensity adjusting unit may include an adjusting electrode provided to surround said electron beams from said substrate to said lens opening, said adjusting electrode being insulated from said magnetic conductive members. 
     The lens-intensity adjusting unit may include a plurality of adjusting electrodes provided to surround said electron beams, respectively, from said substrate to said lens opening. 
     The lens-intensity adjusting unit may further include a means operable to apply different voltages to said plurality of adjusting electrodes. 
     The lens-intensity adjusting unit may further include an adjusting coil operable to adjust magnetic field intensities in said lens openings, said adjusting coil being provided to surround said electron beams from said substrate along a direction in which said electron beams are radiated. 
     The multi-axis electron lens may further include a non-magnetic conductive member having a plurality of through holes, said non-magnetic conductive member being provided between said plurality of magnetic conductive members, said plurality of openings of said magnetic conductive members and said plurality of through holes forming together said plurality of lens openings. 
     The multi-axis electron lens may further include a coil part having a coil provided in an area surrounding said magnetic conductive members for generating a magnetic field and a coil magnetic conductive member provided in an area surrounding said coil. 
     The coil magnetic conductive member may be formed from a material having a different magnetic permeability from that of a material for said plurality of magnetic conductive members. 
     The electron beam exposure apparatus may further comprise at least one further multi-axis electron lens operable to reduce cross sections of said electron beams. 
     The electron beam exposure apparatus may further comprise an electron beam shaping unit that comprises: a first shaping member having a plurality of first shaping openings operable to shape said plurality of electron beams; a first shaping-deflecting unit operable to deflect said plurality of electron beams after passing through said first shaping member, independently of each other; and a second shaping member having a plurality of second shaping openings operable to shape said plurality of electron beams after passing through said first shaping-deflecting unit to have desired shapes. 
     The electron beam shaping unit may further include a second shaping-deflecting unit operable to deflect said plurality of electron beams deflected by said first shaping-deflecting unit independently of each other toward a direction substantially perpendicular to a surface of said wafer onto which said electron beams are incident, wherein said electron beam shaping unit allows said plurality of electron beams deflected by said second shaping-deflecting unit to pass through said second shaping member so as to shape said electron beams to have said desired shapes. 
     The second shaping member may include a plurality of shaping-member illumination areas onto which said electron beams deflected by the second shaping-deflecting unit are incident, and said second shaping member includes said second shaping openings and other openings having different sizes from sizes of said second shaping openings in said shaping-member illumination area. 
     The electron beam exposure apparatus may further comprise: a plurality of electron guns operable to generate said plurality of electron beams; and a further multi-axis electron lens operable to converge said plurality of electron beams generated by said plurality of electron guns to make said converged electron beams incident on said first shaping member, wherein said first shaping member divides said electron beams after passing through said further multi-axis electron lens. 
     The electron beam exposure apparatus may comprise a plurality of multi-axis electron lenses having said lens openings. 
     The multi-axis electron lens may further include a plurality of dummy openings through which no electron beam passes. 
     The plurality of dummy openings may be provided in outer peripheries of an area where said plurality of lens openings are arranged. 
     According to the second aspect of the present invention, an electron lens for converging a plurality of electron beams independently of each other, comprising a plurality of magnetic conductive members arranged to be substantially parallel to each other, said magnetic conductive members having a plurality of openings, wherein said plurality of openings of said magnetic conductive members form a plurality of lens openings allowing said plurality of electron beams to pass therethrough, respectively, to converge said electron beams independently of each other, said lens openings having different shapes. 
     According to the third aspect of the present invention, a fabrication method of a semiconductor device on a wafer, comprising: performing focus adjustments for said plurality of electron beams independently of each other by using a multi-axis electron lens having a plurality of lens openings having different shapes that allow a plurality of electron beams to pass therethrough, respectively, to converge said electron beams independently of each other; and exposing a pattern onto said wafer by illuminating said wafer with said plurality of electron beams. 
     The summary of the invention does not necessarily describe all necessary features of the present invention. The present invention may also be a sub-combination of the features described above The above and other features and advantages of the present invention will become more apparent from the following description of the embodiments taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows an electron beam exposure apparatus  100  according to an embodiment of the present invention. 
     FIG. 2 schematically shows an arrangement of a voltage controller  520 . 
     FIG. 3 shows another example of an electron beam shaping unit. 
     FIG. 4 shows an exemplary structure of a blanking electrode array  26 . 
     FIG. 5 shows a cross section of the blanking electrode array  26 . 
     FIG. 6 schematically shows a structure of a first shaping deflecting unit  18 . 
     FIGS. 7A,  7 B and  7 C schematically show an exemplary arrangement of the deflector  184 . 
     FIG. 8 shows a first multi-axis electron lens  16  that is an electron lens according to an embodiment of the present invention. 
     FIG. 9 shows another exemplary first multi-axis electron lens  16 . 
     FIG. 10 shows another exemplary first multi-axis electron lens  16 . 
     FIG. 11 shows another exemplary first multi-axis electron lens  16 . 
     FIGS. 12A and 12B show examples of the cross section of the first multi-axis electron lens  16 . 
     FIG. 13 shows another exemplary multi-axis electron lens. 
     FIGS. 14A and 14B show other examples of the lens part  200 . 
     FIGS. 15A and 15B show another example of the lens part  202 . 
     FIGS. 16A,  16 B and  16 C shows other examples of the lens part  202 . 
     FIGS. 17A and 17B show an example of a lens-intensity adjuster for adjusting the lens intensity of the multi-axis electron lens. 
     FIGS. 18A and 18B show another exemplary lens-intensity adjuster. 
     FIGS. 19A and 19B show an exemplary arrangement of a first shaping-deflecting unit  18  and a blocking unit  600 . 
     FIG. 20 shows a specific example of first and second blocking electrodes  604  and  610 . 
     FIGS. 21A and 21B show another example of the first shaping-deflecting unit  18  and the blocking unit  600 . 
     FIG. 22 shows another exemplary arrangement of the first shaping-deflecting unit  18 . 
     FIGS. 23A and 23B show an exemplary arrangement of a deflecting unit  60 , a fifth multi-axis electron lens  62  and a blocking unit  900 . 
     FIG. 24 shows an electric field blocked by the blocking unit  600  or  900 . 
     FIG. 25 shows an example of the first and second shaping members  14  and  22 . 
     FIGS. 26A,  26 B,  26 C,  26 D and  26 E show exemplary pattern openings  566  of the second shaping member  22 . 
     FIG. 27 shows an exemplary arrangement of a controlling system  140  shown in FIG.  1 . 
     FIG. 28 shows details of components included in an individual controlling system  120 . 
     FIG. 29 shows an example of a backscattered electron detector  50 . 
     FIG. 30 shows another exemplary backscattered electron detector  50 . 
     FIG. 31 shows another exemplary backscattered electron detector  50 . 
     FIG. 32 shows another exemplary backscattered electron detector  50 . 
     FIG. 33 shows an electron beam exposure apparatus  100  according to another embodiment of the present invention. 
     FIGS. 34A and 34B show an exemplary arrangement of the electron beam generator  10 . 
     FIGS. 35A and 35B show an exemplary arrangement of the blanking electrode array  26 . 
     FIGS. 36A and 36B shows an exemplary arrangement of the first shaping-deflecting unit  18 . 
     FIG. 37 illustrates an exposure operation for a wafer  44  on the electron beam exposure apparatus  100  according to the second embodiment. 
     FIGS. 38A and 38B schematically show deflection operations of the main deflecting unit  42  and the sub-deflecting unit  38  in the exposure process. 
     FIG. 39 shows an example of the first multi-axis electron lens  16 . 
     FIGS. 40A and 40B show examples of the cross section of the first multi-axis electron lens  16 . 
     FIG. 41 shows an electron beam exposure apparatus  100  according to still another embodiment of the present invention. 
     FIGS. 42A and 42B show an exemplary arrangement of the BAA device  27 . 
     FIGS. 43A and 43B show the third multi-axis electron lens  34 . 
     FIGS. 44A and 44B show the deflecting unit  60 . The 
     FIGS. 45A through 45G illustrate an exemplary fabrication process of the lens part  202  of the multi-axis electron lens according to an embodiment of the present invention. 
     FIGS. 46A through 46E illustrate exemplary processes for forming projections  218 . 
     FIGS. 47A and 47B illustrate another example of the fabrication method of the lens part  202 . 
     FIGS. 48A,  48 B and  48 C illustrate a fixing process for fixing the coil part  200  and the lens part  202 . 
     FIG. 49 is a flowchart of processes for fabricating a semiconductor device from a wafer according to an embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention will now be described based on the preferred embodiments, which do not intend to limit the scope of the present invention, but exemplify the invention. All of the features and the combinations thereof described in the embodiment are not necessarily essential to the invention. 
     FIG. 1 shows an electron beam exposure apparatus  100  according to an embodiment of the present invention. The electron beam exposure apparatus  100  includes an exposure unit  150  for performing a predetermined exposure process for a wafer  44  with electron beams and a controlling system  140  for controlling operations of respective components included in the exposure unit  150 . 
     The exposure unit  150  includes: a body  8  provided with a plurality of exhaust holes  70 ; an electron beam shaping unit which can emit a plurality of electron beams and shape a cross-sectional shape of each electron beam so that each electron beam has a desired shape; an illumination switching unit which can independently switch for each electron beam whether or not the electron beam is cast onto the wafer  44 ; and an electron optical system including a wafer projection system which can adjust the orientation and size of a pattern image transferred onto the wafer  44 . In addition, the exposure unit  150  includes a stage system having a wafer stage  46  on which the wafer  44 , onto which the pattern is to be transferred by exposure, can be placed and a wafer-stage driving unit  48  which can drive the wafer stage  46 . 
     The electron beam shaping unit includes an electron beam generator  10  which can generate a plurality of electron beams, an anode  13  which allows the generated electron beams to be radiated, a slit cover  11  having a plurality of openings for shaping the cross-sectional shapes of the electron beams by allowing the electron beams to pass there-through, a first shaping member  14 , a second shaping member  22 , a first multi-axis electron lens  16  which can converge the electron beams to adjust focal points of the electron beams independently of each other, a first lens-intensity adjuster  17  which can adjust the lens intensity which is the force that the magnetic field, which is formed in each lens opening of the first multi-axis electron lens  16 , gives to the electron beam passing through the lens opening, 
     The electron beam generator  10  includes an insulator  106 , cathodes  12  which can generate thermoelectrons, and grids  102  formed to surround the cathodes  12  so as to stabilize the thermoelectrons generated by the cathodes  12 . It is preferable that the cathodes  12  and the grids  102  are electrically insulated from each other. In this example, the electron beam generator  10  forms an electron gun array by having a plurality of electron guns  104  arranged at a predetermined interval on the insulator  106 . 
     It is desirable that the slit cover  11  and the first and the second shaping member  14  and  22  have grounded metal films such as platinum films, on surfaces thereof onto which the electron beams are cast. It is also desirable that each of the slit covers  11 , the first shaping member  14  and the second shaping member  22  include a cooling unit for suppressing the increase in the temperature caused by the incident electron beams. 
     The openings included in each of the slit covers  11 , the first shaping member  14  and the second shaping member may have cross-sectional shapes each of which becomes wider along the radiated direction of the electron beams in order to allow the electron beams to pass efficiently. Moreover, the openings of each of the slit covers  11 , the first shaping member  14  and the second shaping member  22  are preferably formed to be rectangular. 
     The illumination switching unit includes: a second multi-axis electron lens  24  which can converge a plurality of electron beams independently of each other and adjust focal points thereof; a second lens-intensity adjuster  25  which can independently adjust the lens-intensity in each lens opening of the second multi-axis electron lens  24 ; a blanking electrode array  26  which switches for each of the electron beams whether or not the electron beam is allowed to reach the wafer  44  by deflecting the electron beam independently of each other; and an electron beam blocking member  28  that has a plurality of openings allowing the electron beams to pass there-through and can block the electron beams deflected by the blanking electrode array  26 . The openings of the electron beam blocking member  28  may have cross-sectional shapes each of which becomes wider along the illumination direction of the electron beams in order to allow the electron beams to efficiently pass there-through. 
     The wafer projection system includes: a third multi-axis electron lens  34  which can converge a plurality of electron beams independently of each other and adjust the rotations of the electron beams to be incident onto the wafer  44 ; a third lens-intensity adjuster  35  which can independently adjust the lens intensity in each lens opening of the third multi-axis electron lens  34 ; a fourth multi-axis electron lens  36  which can converge a plurality of electron beams independently of each other and adjust the reduction ratio of each electron beam to be incident onto the wafer  44 ; a fourth lens-intensity adjuster  37  which can independently adjust the lens intensity in each of lens openings of the fourth multi-axis electron lens  36 ; a deflecting unit  60  which can deflect a plurality of electron beams independently of each other to direct desired portions on the wafer  44 ; and a fifth multi-axis electron lens  62  which can function as an objective lens for the wafer  44  by converging a plurality of electron beams independently of each other. In this example, the third multi-axis electron lens  34  and the fourth multi-axis electron lens  36  are integrated with each other. In an alternative example, however, the third and fourth multi-axis electron lenses may be formed as separate components. 
     The controlling system  140  includes a general controller  130 , a multi-axis electron lens controller  82 , a backscattered electron processing unit  99 , a wafer-stage controller  96  and an individual controller  120  which can control exposure parameters for each of the electron beams. The general controller  130  is, for example, a work station and can control the respective controllers included in the individual controller  120 . The multi-axis electron lens controller  82  controls currents to be respectively supplied to the first multi-axis electron lens  16 , the second multi-axis electron lens  24 , the third multi-axis electron lens  34  and the fourth multi-axis electron lens  36 . The backscattered electron processing unit  99  receives a signal based on the amount of backscattered electrons or secondary electrons detected in a backscattered electron detector  50  and notifies the general controller  130  that the backscattered electron processing unit  99  received the signal. The wafer-stage controller  96  controls the wafer-stage driving unit  48  so as to move the wafer stage  46  to a predetermined position. 
     The individual controller  120  includes an electron beam controller  80  for controlling the electron beam generator  10 , a shaping-deflector controller  84  for controlling the first and second-shaping deflecting units  18  and  20 , a lens-intensity controller  88  for controlling the first, second, third and fourth lens-intensity adjusters  17 ,  25 ,  35  and  37 , a blanking electrode array controller  86  for controlling voltages to be applied to deflection electrodes included in the blanking electrode array  26 , and a deflector controller  98  for controlling voltages to be applied to electrodes included in the deflectors of the deflecting unit  60 . 
     Next, the operation of the electron beam exposure apparatus  100  in the present embodiment is described. First, the electron beam generator  10  generates a plurality of electron beams. The generated electron beams pass the anode  13  to enter a slit-deflecting unit  15 . The slit-deflecting unit  15  adjusts the incident positions on the slit cover  11  onto which the electron beams that have passed through the anode  13  are incident. 
     The slit cover  11  can block a part of each electron beam so as to reduce the area of the electron beam incident on the first shaping member  14 , thereby shaping the cross section of the electron beam to have a predetermined size. The thus shaped electron beam is incident on the first shaping member  14  in which it is further shaped. Each of the electron beams that have passed through the first shaping member  14  has a rectangular cross section in accordance with a corresponding one of the openings included in the first shaping member  14 . 
     The first multi-axis electron lens  16  converges the electron beams that have been shaped to have rectangular cross sections by the first shaping member  14  independently of other electron beams, thereby the focus adjustment of the electron beam with respect to the second shaping member  22  can be performed for each electron beam. The first lens-intensity adjuster  17  adjusts the lens intensity in each lens opening of the first electron lens  16  in order to correct the focal point of the corresponding electron beam incident on the lens opening. 
     The first shaping deflecting unit  18  deflects each of the electron beams having the rectangular cross sections independently of the other electron beams, in order to make the electron beams incident on desired positions on the second shaping member  22 . The second shaping deflecting unit  20  further deflects the thus deflected electron beams independently of each other in a direction approximately perpendicular to the second shaping member  22 , thereby making adjustment in such a manner that the electron beams are incident on the desired positions of the second shaping member  22  approximately perpendicular to the second shaping member  22 . The second shaping member  22 , having a plurality of rectangular openings, further shapes the electron beams incident thereon in such a manner that the electron beams have desired rectangular cross sections respectively when being incident on the wafer  44 . In this example, the first shaping deflecting unit  18  and the second shaping deflecting unit  20  are provided on the same substrate as shown in FIG.  1 . In an alternative example, however, the first and second shaping deflecting units  18  and  20  may be formed separately. 
     The second multi-axis electron lens  24  converges the electron beams that have passed through the second shaping deflecting unit  20  independently of each other so as to perform the focus adjustment of the electron beam with respect to the blanking electrode array  26  for each electron beam. The second lens-intensity adjuster  25  adjusts the lens intensity in each lens opening of the second multi-axis electron lens  24  in order to correct the focal point of each electron beam incident onto the lens opening. The electron beams having the focal points adjusted by the second multi-axis electron lens  24  then pass through a plurality of apertures included in the blanking electrode array  26 , respectively. 
     The blanking electrode array controller  86  controls whether or not voltages are applied to deflection electrodes provided in the vicinity of the respective apertures of the blanking electrode array  26 . Based on the voltages applied to the deflection electrodes, the blanking electrode array  26  switches for each of the electron beams whether or not the electron beam is to be incident on the wafer  44 . When the voltage is applied, the electron beam passing through the corresponding aperture is deflected. Thus, the electron beam cannot pass a corresponding opening of the electron beam blocking member  28 , so that it cannot be incident on the wafer  44 . When the voltage is not applied, the electron beam passing through the corresponding aperture is not deflected, so that it can pass through the corresponding opening of the electron beam blocking member  28 . Thus, the electron beam can be incident on the wafer  44 . 
     The third multi-axis electron lens  34  adjusts the rotation of the electron beams that have passed through the blanking electrode array  26 . More specifically, the third multi-axis electron lens  34  adjusts the rotation of the image of the electron beams illuminated onto the wafer  44 . The third lens-intensity adjuster  35  also adjusts the lens intensity in each lens opening of the third multi-axis electron lens  36  in order to make the rotations of the images of the respective electron beams incident on the third multi-axis electron lens  34  uniform. 
     The fourth multi-axis electron lens  36  reduces the illumination diameter of each of the electron beams incident thereon. The fourth lens-intensity adjuster  37  adjusts the lens intensity in each lens opening of the fourth multi-axis electron lens  36 , thereby making the reduction rates of the electron beams substantially the same. Among the electron beams that have passed through the third multi-axis electron lens  34  and the fourth multi-axis electron lens  36 , only the electron beam to be incident onto the wafer  44  passes through the electron beam blocking member  27 , so as to enter the deflecting unit  60 . 
     The deflector controller  98  controls a plurality of deflectors included in the deflecting unit  60  independently of each other. The deflecting unit  60  deflects the electron beams incident on the deflectors thereof independently of each other, in such a manner that the deflected electron beams are incident on the desired positions on the wafer  44 . The fifth multi-axis electron lens  62  further adjusts the focus of the electron beams incident on the deflecting unit  60  with respect to the wafer  44  independently of each other. Then, the electron beams that have passed through the deflecting unit  60  and fifth multi-axis electron lens  62  can be incident on the wafer  44 . 
     During the exposure process, the wafer-stage controller  96  moves the wafer stage  48  in predetermined directions. The blanking electrode array  86  determines the apertures that allow the electron beams to pass there-through and performs electric-power control for the respective apertures. In accordance with the movement of the wafer  44 , the apertures allowing the electron beams to pass there-through are changed and the electron beams that have passed through the apertures are further deflected by the deflecting unit  60 , thereby the wafer  44  is exposed to have a desired circuit pattern transferred. 
     The multi-axis electron lens of the present invention converges a plurality of electron beams independently of each other. Thus, although a cross over is formed for each electron beam, all the electron beams as a whole do not have a crossover. Therefore, even in a case where the current density of each electron beam is increased, the electron beam error, which may cause a shift of the focus or position of the electron beam due to coulomb interaction, can be decreased. Accordingly, the current density of each electron beam can be reduced, greatly shortening the exposure time. 
     FIG. 2 schematically shows an arrangement of a voltage controller  520  which can apply a predetermined voltage to the electron beam generator  10 . The voltage controller  520  includes a base power source  522  that generates the predetermined voltage, and adjusting power sources  524  that increase or reduce the predetermined voltage and apply the increased or reduced voltages to the respective cathodes  12 . 
     The voltage controller  520  controls an acceleration voltage of each electron beam by controlling the voltage to be applied to the cathode  12  based on an instruction from the electron beam controller  80 . It is preferable that the voltage controller  520  may control the acceleration voltage of each electron beam by applying, to the cathode  12  of the corresponding electron gun, the voltage that depends on the magnetic-field intensity applied to the electron beam by the multi-axis electron lenses  16 ,  24 ,  34 ,  36  and  62 . 
     Moreover, it is preferable that the voltage controller  520  controls the acceleration voltages of the respective electron beams by applying different voltages to the cathodes of the electron guns, the voltages being determined in such a manner that the positions of the focal points of the respective electron beams to be incident on the wafer  44  are equal to each other. Furthermore, the voltage controller  520  may further control the acceleration voltages of the electron beams by applying different voltages to the cathodes  12  of the electron guns in such a manner that predetermined sides of the cross sections of the respective electron beams to be incident on the wafer  44  are substantially parallel to each other. 
     In this example, the base power source  522  generates a voltage of 50 kV. Each of the adjusting power sources  524  increases or lowers the voltage generated by the base power source  522  in accordance with the magnetic-field intensities generated in the lens openings of the multi-axis electron lenses  16 ,  24 ,  34 ,  36  and  62  through which the electron beam generated by the corresponding cathode  12  passes, so that the adjusted voltage is applied to the corresponding cathode  12 . In a case where the magnetic-field intensity in the lens opening on the center of the multi-axis electron lens is weaker than that in the outer periphery of the multi-axis electron lens by 3%, for example, the acceleration voltage of the cathode  12  for generating an electron beam that is to pass through the lens opening on the center of the multi-axis electron lens is increased by 3%. 
     The electron beam controller  80  can adjust a time period for which each of the electron beams passes through the lens opening by controlling the acceleration voltage for the electron beam, even if the intensity of the magnetic field in the lens opening of the multi-axis electron lens is varied. Thus, the electron beam controller  80  can control effects of the magnetic field on the respective electron beams in the lens openings. Also, the electron beam controller  80  can control the focal point positions of the electron beams with respect to the wafer  44  and the rotation of the exposure images of the electron beams to be incident on the wafer  44 . 
     FIG. 3 shows another example of the electron beam shaping unit. The electron beam shaping unit of this example further includes a first illumination multi-axis electron lens  510  and a second illumination multi-axis electron lens  512  for converging the electron beams generated by the electron beam generator  10  independently of each other so as to allow the converged electron beams to be incident on the first shaping member  14 . The first and second illumination multi-axis electron lenses  510  and  512  are provided between the electron beam generator  10  and the first shaping member  14 . 
     The number of the lens openings included in each of the first and second illumination multi-axis electron lenses  510  and  512  is preferably less than the number of the lens openings of the first multi-axis electron lens  16 . It is also preferable that the opening size of the lens opening of the first and second illumination multi-axis lenses  510  and  512  is larger than that of the first multi-axis lens  16 . The number of the lens openings of each of the first and second illumination multi-axis electron lenses  510  and  512  may be the same as the number of the cathodes  12  included in the electron beam generator  10 . Moreover, each of the first and second illumination multi-axis electron lenses  510  and  512  may further include at least one dummy lens opening through which no electron beam passes during the exposure process. 
     The first illumination multi-axis electron lens  510  adjusts the focal point of the electron beams generated at the electron beam generator  10 . More specifically, it is preferable that the first illumination multi-axis electron lens  510  adjusts the focal point of each of the electron beams, so that each of the electron beams, which have passed through the first illumination multi-axis electron lens  510 , form a cross over between the first and the second illumination multi-axis electron lens  510  and  512 . Then, the second illumination multi-axis electron lens  512  performs a further focus adjustment for the electron beam that has been subjected to the focus adjustment in the first illumination multi-axis electron lens  510 , so as to make the electron beam incident on the first shaping member  14 . In this case, it is preferable that the second illumination multi-axis electron lens  512  adjusts the focal points of the electron beams incident thereon in such a manner that the electron beams after passing through the second illumination multi-axis electron lens  512  are incident on the first shaping member  14  substantially perpendicular thereto. 
     The electron beams after passing through the first and second illumination multi-axis electron lenses  510  and  512  are incident on the first shaping member  14 , in which the electron beams are divided. The respective divided electron beams are independently converged of each other by the first multi-axis electron lens  16 . The electron beams are then deflected by the first and second shaping deflecting units  18  and  20 , and are incident on the desired positions on the second shaping member  22 . The second shaping member  22  shapes the electron beams to have desired cross-sectional shapes. In addition, the electron beam shaping unit may further include the slit cover  11  (shown in FIG. 1) between the electron beam generator  10  and the first shaping member  14 . 
     As described above, the electron beam shaping unit  110  of this example can cast the electron beams generated by the electron beam generator  10  onto the first shaping member  14  by means of the illumination multi-axis electron lenses to divide the cast electron beams. Therefore, even in a case where the interval between the cathodes  12  of the electron beam generator  10  that is an electron gun array is relatively large, for example, a number of electron beams can be generated efficiently. Also, since the interval between the cathodes  12  can be made larger, it is possible to form the electron beam generator  10  easily. 
     FIG. 4 schematically shows an exemplary structure of the blanking electrode array  26 . The blanking electrode array  26  includes an aperture part  160  having a plurality of apertures  166  that allow the electron beams passing there-through, respectively, deflecting electrode pads  162  and grounded electrode pads  164  that are to be used as connections with the blanking electrode array controller  86  shown in FIG.  1 . It is desirable that the aperture part  160  is arranged at the center of the blanking electrode array  26 . It is also preferable that the blanking electrode array  26  has at least one dummy opening through which no electron beam passes in an area surrounding the aperture part  160 . When the blanking electrode array  26  has the dummy opening, the inductance of exhaustion can be reduced, thus allowing the pressure in the body  8  to be lowered efficiently. 
     FIG. 5 shows a cross section of the blanking electrode array  26  shown in FIG.  4 . The blanking electrode array  26  has the apertures  166  each of which can allow the corresponding electron beam to pass there-through, a deflecting electrode  168  and a grounded electrode  170  provided for each aperture that are used for deflecting the passing electron beam, and the deflecting electrode pads  166  and the grounded electrode pads  164  to be used as the connection with the blanking electrode array controller  86  (shown in FIG.  1 ), as shown in FIG.  5 . 
     The deflecting electrode  168  and the grounded electrode  170  are provided for each aperture  166 . The deflecting electrode  168  is electrically connected to the deflecting electrode pad  162  via a wiring layer, while the grounded electrode  170  is electrically connected to the grounded electrode pad  164  via a conductive layer. The blanking electrode array controller  86  supplies control signals for controlling the blanking electrode array  26  to the deflecting electrode pads  162  and the grounded electrode pads  164  via connectors such as a probe card or a pogo pin array. 
     Next, the operation of the blanking electrode array  26  is described. When the blanking electrode array controller  86  does not apply the voltage to the deflecting electrode  168  of the aperture  166 , no electric field is generated between the deflecting electrode  168  and the associated grounded electrode  170 . Thus, the electron beam entering the aperture  166  passes through the aperture  166  with no substantial effect of the electric field. The electron beam that has passed through the aperture then passes through the corresponding opening of the electron beam blocking member (shown in FIG. 1) so as to reach the wafer  44 . 
     When the blanking electrode array controller  86  applies the voltage to the deflecting electrode  168  of the aperture  166 , an electric field is generated between the deflecting electrode  168  and the associated grounded electrode  170  based on the applied voltage. Thus, the electron beam entering the aperture  166  is affected by the generated electric field so as to be deflected. More specifically, the electron beam is deflected in such a manner that the electron beam after passing through the aperture is incident on the outer area of the corresponding opening of the electron beam blocking member  28 . Therefore, the deflected electron beam can pass through the aperture but cannot pass through the corresponding opening of the electron beam blocking member  28 , failing to reach the wafer  44 . The blanking electrode array  26  and the electron beam blocking member  28  operate in the above-mentioned manner, thereby it can be switched for each electron beam independently of other electron beams whether or not the electron beam is incident on the wafer  44 . 
     FIG. 6 schematically shows a structure of the first shaping deflecting unit  18  for deflecting the electron beams. It should be noted that the second shaping deflecting unit  20  and the deflecting unit  60  included in the electron beam exposure apparatus  100  can have the same structure as that of the first shaping deflecting unit  18 . Thus, only the structure of the first shaping deflecting unit  18  is described below as a typical example. 
     The first shaping deflecting unit  18  includes a substrate  186 , a deflector array  180  and deflecting electrode pads  182 . The deflector array  180  is provided at the center of the substrate  186 . The deflecting electrode pads  182  are desirably arranged in peripheral areas of the substrate  186 . It is preferable that the substrate  186  has at least one dummy opening (see FIG. 1) through which no electron beam passes in an area surrounding the region where the deflector array  180  is provided. 
     The deflector array  180  has a plurality of deflectors  184 , each of which is formed by deflecting electrodes and an opening. The deflecting electrode pads  182  are electrically connected to the shaping-deflector controller  84  (shown in FIG. 1) via connectors such as a probe card or a pogo pin array. Referring to FIG. 4, the deflectors  184  of the deflector array  180  are provided so as to correspond to the apertures of the blanking electrode array  26 , respectively. 
     FIGS. 7A,  7 B and  7 C schematically show an exemplary arrangement of the deflector  184 . As shown in FIG. 7A, the deflector  184  includes an opening  194  through which an electron beam can pass, a plurality of deflecting electrodes  190  which can deflect the electron beam pass through the opening  194 , and wirings  192  for electrically connecting the deflecting electrodes  190  to the deflecting electrode pads  182  (see FIG.  6 ), respectively. The deflecting electrodes  190  are provided to surround the opening  194 . The deflector  184  is preferably an electrostatic type deflector that can deflect the electron beam at high speed by using an electric field, and is more preferably a cylindrical eight-electrode type having four pairs of electrodes in which the electrodes of each pair are opposed to each other. 
     The operation of the deflector  184  is described. When a predetermined voltage is applied to each of the deflecting electrodes  190 , an electric field is generated in the opening  194 . The electron beam incident on the opening  194  is affected by the generated electric field, so as to be deflected in a predetermined direction corresponding to the orientation of the electric field by the amount corresponding to the electric-field intensity. Thus, the electron beam can be deflected to a desired position by applying the voltages to the respective deflecting electrodes  190  so as to generate the electric field that can deflect the electron beam in the desired direction by the desired amount. 
     As shown in FIG. 7B, the deflector  184  can correct astigmatism for the electron beam passing through the opening  194  by applying a predetermined voltage to predetermined ones of the deflecting electrodes  190  that are opposed to each other and applying different voltages to other deflecting electrodes  190 . Moreover, as shown in FIG. 7C, the focus correction can be performed for the electron beam passing through the opening  194  by applying substantially the same voltages to all the deflecting electrodes  190 . 
     FIG. 8 is a top view of the first multi-axis electron lens  16  that is an electron lens according to an embodiment of the present invention. Please note that the second multi-axis electron lens  24 , the third multi-axis electron lens  34 , the fourth multi-axis electron lens  36  and the fifth multi-axis electron lens  62  all included in the electron beam exposure apparatus  100  have the same structure as that of the first multi-axis electron lens  16 . Thus, the structure of the multi-axis electron lens is described referring to the first multi-axis electron lens  16  as a typical example. 
     The first multi-axis electron lens  16  includes a lens part  202  having a plurality of lens openings  204  through which electron beams can pass, respectively, and a coil part  200  provided in an area surrounding the lens part  202  to generate a magnetic field. The lens part  202  includes a lens region  206  where the lens openings  204  are provided. It is preferable that the lens opening  204  is arranged to correspond to the position of the associated aperture  166  of the blanking electrode array  26  and the position of the associated deflector  184  of the deflector array  180 , referring to FIGS. 4 and 6. It is further preferable that each of the lens openings  204  is provided to have substantially the same axis as those of the corresponding openings of the electron beam shaping members, the deflecting units and the blanking electrode array  26 . 
     It is desirable that the lens part  202  has at least one dummy opening  205  through which no electron beam passes. The dummy opening  205  is desirably arranged in the lens part  202  so as to make the lens intensity in each lens opening  204  substantially equal to the lens intensity in the other lens opening  204 . Such dummy openings  205  provided in the lens part  202  enable the adjustment of the lens intensity so as to be substantially equal in all the lens openings  204 , i.e., to make the magnetic field intensity substantially uniform at all the lens openings  204 . 
     In this example, the dummy openings  205  are provided in the outer region of the lens region  206 . In this case, the lens openings  204  and the dummy openings  205  may be provided to form a lattice including the lens openings  204  and the dummy openings  205  as lattice points. Moreover, the dummy openings  205  may be arranged to be circular in the outer periphery of the lens region  206 . In an alternative example, the dummy openings  205  maybe arranged inside of the lens region  206  in the lens part  206 . By adjusting the arrangement of the dummy openings  205 , the lens intensity in each lens opening  204  can be more finely adjusted. 
     The lens part  202  may include the dummy opening  205  having different sizes and/or shapes from those of the lens openings  204 . In this case, the lens intensities in the lens openings  204  can be more finely adjusted by adjusting the sizes and/or shapes of the dummy openings  205 . 
     FIG. 9 is a top view of another exemplary first multi-axis electron lens  16 . The lens part  202  may include the dummy openings  205  arranged to multiple plies. In this case, the lens openings  204  and the dummy openings  205  may be arranged to form a lattice including the lens openings  204  and the dummy openings  205  as lattice points. Moreover, the dummy openings  205  may be provided to form a circle in the outer peripheral region of the lens region  206 . Furthermore, the lens part  202  may include the dummy openings  205  in the outer peripheral region of the lens region  206 , some of which are arranged to form a lattice while the remaining ones are arranged to be circular. The first multi-axis electron lens  16  can perform further fine adjustment of the lens intensity in each lens opening  204  by including the dummy openings  205  arranged to be multiple plies. 
     FIG. 10 shows another exemplary first multi-axis electron lens  16 . The lens part  202  may include a plurality of dummy openings  205  having different opening sizes in the outer peripheral region of the lens region  206 . For example, in a case where the magnetic field generated in the lens opening  204  in the outer peripheral region of the lens region  206  is stronger than that at the center thereof, it is preferable that a particular lens opening  204  is formed to have a larger opening size than that of other lens openings  204  positioned on the inner side of the predetermined lens opening  204 . It is also preferable that the opening sizes of the lens openings  204  are substantially symmetrical with respect to a center axis of the lens region  206  where the lens openings  204  are provided. 
     The lens part  202  may include the dummy openings  205  having different opening sizes to be multiple plies in the outer peripheral region of the lens region  206 . In this case, the lens openings  204  and the dummy openings  205  may be arranged to form a lattice. Also, the dummy openings  205  may be formed to be circular in the outer peripheral region of the lens region  206 . The first multi-axis electron lens  16  can perform further fine adjustment of the lens intensity in each lens opening  204  by including the dummy openings  205  having the different opening sizes arranged to be multiple plies. 
     FIG. 11 shows another exemplary first multi-axis electron lens  16 . As shown in FIG. 11, the lens part  202  may include the dummy lens openings  205  arranged in such a manner that a distance between the dummy opening  205  and the adjacent lens opening  204  is different from a distance between the lens openings  204 . Also, the lens part  202  may include the dummy openings  205  arranged to be multiple plies at different intervals there-between. The first multi-axis electron lens  16  can perform further fine adjustment of the lens intensity in each lens opening  204  by including the dummy openings  205  having the appropriately adjusted distances to the adjacent lens openings  204 . 
     FIG. 12A shows an exemplary cross section of the first multi-axis electron lens  16 . Please note that the second multi-axis electron lens  24 , the third multi-axis electron lens  34 , the fourth multi-axis electron lens  36  and the fifth multi-axis electron lens  62  may have the same structure as that of the first multi-axis electron lens  16 . Thus, the structure of the multi-axis electron lens is described below based on that of the first multi-axis electron lens  16  as a typical example. 
     As shown in FIG. 12A, the first multi-axis electron lens  16  includes coils  214 , coil-magnetic conductive members  212  provided in areas surrounding the coils  214  and cooling units  215  provided between the coils  214  and the coil-magnetic conductive members  212  that can cool the coils  214 . The lens part  202  includes a lens-magnetic conductive member  210  that is a magnetic conductive member and a plurality of openings provided in the lens-magnetic conductive member  210 . These openings serve as the lens openings  204  allowing the electron beams to pass there-through. 
     In this example, the lens-conductive member  210  includes a first lens-magnetic conductive member  210   a  and a second lens-magnetic conductive member  210   b , both of which have a plurality of openings. It is preferable that the first lens-magnetic conductive member  210   a  and the second lens-magnetic conductive member  210   b  are arranged to be substantially parallel to each other with a non-magnetic conductive member  208  interposed there-between. The openings provided in the first and second lens-magnetic conductive members  210   a  and  210   b  form the lens openings  204 . In other words, the magnetic field is generated in the lens openings  204  by the first and second lens-magnetic conductive members  210   a  and  210   b . The electron beams entering the lens openings  204  are converged independently of each other by the effects of the magnetic field between the lens-magnetic conductive members  210   a  and  210   b  without forming a crossover. 
     The coil magnetic conductive members  212  may be formed from magnetic conductive material having a magnetic permeability different from that of material for the first and second lens magnetic conductive members  210   a  and  210   b . It is desirable that the material for the coil magnetic conductive member  212  has magnetic permeability higher than that of the material for the lens magnetic conductive members  210   a  and  210   b . For example, the coil magnetic conductive members  212  are formed of malleable iron while the lens magnetic conductive members  210  are formed of Permalloy. By forming the coil magnetic conductive members from the material different from that for the lens magnetic conductive members, the intensities of the magnetic fields generated in the lens openings  204  can be made uniform. 
     As shown in FIG. 12B, it is preferable that the lens part  202  has a non-magnetic conductive member  208  between the lens magnetic conductive members  210  in the areas other than the areas in which the lens openings  204  are provided. The non-magnetic conductive member  208  may be provided to fill a space between the lens magnetic conductive members  210  in the areas other than the areas in which the lens openings  204  are provided. In this case, the non-magnetic member  208  has through holes that form the lens openings  204  together with the openings of the lens magnetic conductive members  210 . The non-magnetic conductive member  208  has a function of blocking the coulomb force generated between the adjacent electron beams passing through the lens openings  204 . The non-magnetic conductive member  208  also serves as a spacer between the first lens magnetic conductive member  210   a  and the second lens magnetic conductive member  210   b  when the lens part  202  is formed. 
     FIG. 13 shows another exemplary multi-axis electron lens. A plurality of multi-axis electron lens may be integrated with each other to form a single multi-axis electron lens. In this example, the multi-axis electron lens includes the first and second magnetic conductive members  210   a  and  210   b , and further includes the third magnetic conductive members  210   c  arranged to be substantially parallel to the first and second magnetic conductive members  210   a  and  210   b , as shown in FIG.  13 . Moreover, the coil part  200  includes a plurality of coils  200 . 
     The openings provided in the respective magnetic conductive members  210   a ,  210   b  and  210   c  form the lens openings  204 . The magnetic fields are formed between the first and second magnetic conductive members  210   a  and  210   b  and between the first and third magnetic conductive members  210   a  and  210   c . When the magnetic conductive members  210   b  and  210   c  are arranged to be away from the conductive member  210   a  by different distances, the different lens intensities can be obtained between the respective lens magnetic conductive members  210   a ,  210   b  and  210   c . As described above, the multi-axis electron lens of this example is formed by integrating a plurality of multi-axis electron lenses together. Thus, the size of the lens serving as a plurality of multi-axis electron lenses can be reduced. Also, this size reduction of the lens can reduce the size of the electron beam exposure apparatus  100 . 
     FIGS. 14A and 14B show other examples of the lens part  200 . At least one of the lens magnetic conductive members  210   a  and  210   b  may include at least one cut portion  216  formed in the outer periphery of each opening, as shown in FIG.  14 A. In this case, it is preferable to form the cut portions  216  on a face of the first lens magnetic conductive member  210   a  and a face of the second lens magnetic conductive member  210   b  that are opposed to each other. 
     Moreover, the lens magnetic conductive members  210   a  and  210   b  preferably include the cut portions  216  having different dimensions. More specifically, the depths of the cut portions  216  in a depth direction of the lens magnetic conductive members  210   a  and  210   b  may be different. Also, the sizes of the cut portions  216  may be changed to make the sizes of the openings provided in the lens magnetic conductive members  210   a  and  210   b  different. 
     In a case where the intensity of the magnetic field generated in the lens opening  204  in the vicinity of the outer periphery of the lens magnetic conductive members  210  is stronger than that at the center of the lens magnetic conductive members  210 , for example, it is preferable to make the dimension of a certain cut portion  216  larger than that of the cut portion  216  arranged on the inner side of the certain cut portion  216 . Moreover, it is preferable that the dimensions of the cut portions  216  are determined to be symmetrical with respect to the center axis of the lens region  206  that is a region of the lens magnetic conductive members  210  in which the lens openings  204  are provided. 
     The lens magnetic conductive members  210  can adjust the intensities of the magnetic fields generated in the lens openings  204  by including the cut portions  216 . Alternatively, as shown in FIG. 14B, the lens magnetic conductive members  210  may include magnetic projections  218  having electro-conductivity provided between adjacent openings of the lens magnetic conductive members  210  so as to project from surfaces of the lens magnetic conductive members  210  that are opposed to each other. In this case, the same effects obtained in the case of including the cut portions  216  can be obtained. 
     FIGS. 15A and 15B show another example of the lens part  202 . As shown in FIG. 15A, the lens part  202  includes a plurality of first sub-magnetic conductive members  240   a  provided in areas surrounding the openings of the first lens magnetic conductive member  210   a  and a plurality of second sub-magnetic conductive members  240   b  provided in areas surroundings the openings of the second lens magnetic conductive member  210   b . The first sub-magnetic conductive members  240   a  and the second sub-magnetic conductive members  240   b  are formed to project from the respective lens magnetic conductive members  210   a  and  210   b , respectively, along the direction in which the electron beams are emitted. 
     It is preferable that the first and second sub-magnetic conductive members  240   a  and  240   b  are cylindrical in a plane substantially perpendicular to the direction in which the electron beams are emitted. In this example, the first sub-magnetic conductive members  240   a  are arranged in the inner faces of the openings of the first lens magnetic conductive members  210   a  while the second sub-magnetic conductive members  240   b  are arranged in the inner faces of the openings of the second lens magnetic conductive members  210   b . The openings formed by the first sub-magnetic conductive members  240   a  and the openings formed by the second sub-magnetic conductive members  240   b  together form the lens openings  204  allowing the electron beams to pass there-through. 
     In the lens openings  204 , magnetic fields are generated by the first and second sub-magnetic conductive members  240   a  and  240   b . The electron beams entering the lens openings  204  are converged independently of each other by effects of the magnetic fields formed between the first and second sub-magnetic conductive members  240   a  and  240   b.    
     A distance between a particular one of the first sub-magnetic conductive members  240   a  and the second sub-magnetic conductive member  240   b  opposed to the particular first sub-magnetic conductive member  240   a  may be different from the distance between another first sub-magnetic conductive member  240   a  and the corresponding second sub-magnetic conductive member  240   b . In a case where the lens part  202  includes a plurality of pairs of the first and second sub-magnetic conductive members  240   a  and  240   b , the distance between the first and second sub-magnetic conductive members  240   a  and  240   b  in one pair being different from that in another pair, as shown in FIG. 15B, the intensity of the magnetic field  220  generated in each lens opening  204  can be adjusted. Thus, it is possible to make the intensities of the magnetic fields in the respective lens openings  204  uniform. Moreover, the lens axis formed in each lens opening  204  can be made substantially parallel to the direction in which the electron beams are emitted. Furthermore, the electron beams passing through the respective lens openings  204  can be converged on substantially the same plane. 
     More specifically, in a case where the intensity of the magnetic field formed in the lens opening  204  in the vicinity of the outer periphery of the lens magnetic conductive member  210  is stronger than that at the center of the lens magnetic conductive member  210 , for example, it is preferable that the distance between the first and second sub-magnetic conductive member  240   a  and  240   b  in a particular pair is larger than the distance between the first and second sub-magnetic conductive members  240   a  and  240   b  in the other pair farther from the coil  200  than the particular pair. Furthermore, it is preferable to determine the distances between the first and second sub-magnetic conductive members  240   a  and  240   b  to be symmetrical with respect to a center axis of a region of the second magnetic conductive member  210   b  where the openings are provided. 
     FIGS. 16A,  16 B and  16 C show other examples of the lens part  202 . As shown in FIG. 16A, the lens part  202  may include fixing parts  242  that are non-magnetic conductive members provided in areas surrounding the first sub-magnetic conductive members  240   a  and the second sub-magnetic conductive members  240   b  arranged on substantially the same axes as the first sub-magnetic conductive members  240   a . By providing the fixing parts  242  in the surrounding areas of the first and second sub-magnetic conductive members  240   a  and  240   b , the concentricity of the first and second sub-magnetic conductive members  240   a  and  240   b  can be controlled with high precision. Moreover, it is desirable to arrange the fixing parts  242  so as to be sandwiched between the first and second sub-magnetic conductive members  240   a  and  240   b  while being in contact with the first and second sub-magnetic conductive members  240   a  and  240   b . In this case, the distance between the first sub-magnetic conductive member  240   a  and the corresponding second sub-magnetic conductive member  240   b  can be controlled with high precision. Furthermore, the fixing part  242  may be provided to be sandwiched between the first magnetic conductive member  210   a  and the corresponding second magnetic conductive member  210   b  while being in contact with the first and second magnetic conductive members  210   a  and  210   b . In this case, the fixing part  242  can serve as a spacer for the first and second magnetic conductive members  210   a  and  210   b.    
     As shown in FIG. 16B, a plurality of sub-magnetic conductive members  240  may be provided on either one of the first and second lens magnetic conductive members  210   a  and  210   b . FIG. 16B shows a case where only the first lens magnetic conductive member  210   a  includes the sub-magnetic conductive members  240  as an example. In this case, the openings provided in the second lens magnetic conductive member  210   b  and the openings formed by the sub-magnetic conductive members  240  provided in the first lens magnetic conductive member  210   a  together form the lens openings  204  allowing the electron beams passing there-through. Moreover, it is preferable that the openings provided in the second lens magnetic conductive member  210   b  have substantially the same sizes as those of the openings formed by the sub-magnetic conductive members  240  provided in the first lens magnetic conductive member  210   a . Please note the above description is also applicable to a case where only the second lens magnetic conductive member  210   b  includes the sub-magnetic conductive members  240 . 
     In addition, the distances between the sub-magnetic conductive members  240  and the corresponding second lens magnetic conductive members  210   b  may be varied, as shown in FIG.  16 B. By varying the distances between the sub-magnetic conductive members  240  and the second lens magnetic conductive members  210   b , it is possible to adjust the intensities of the magnetic fields formed in the respective lens openings  204 . Thus, the intensities of the magnetic fields of the lens openings  204  can be made uniform. Moreover, the magnetic field formed in each lens opening  204  can have a distribution substantially symmetrical with respect to the center axis of the lens opening  204 . Furthermore, the electron beams passing through the respective lens openings  204  can be converged on substantially the same plane. 
     In a case where the intensity of the magnetic field formed in the lens opening  204  is stronger in the vicinity of the outer periphery of the lens magnetic conductive members  210  than that at the center thereof, for example, it is preferable to make the distance between a particular sub-magnetic conductive member  240  and the corresponding second lens magnetic conductive member  210   b  larger than the distance between the sub-magnetic conductive member  240  that is farther from the coil  200  than the particular sub-magnetic conductive member  240  and the corresponding second magnetic conductive member  210   b . Furthermore, it is preferable to determine the distances between the sub-magnetic conductive members  240  and the second lens magnetic conductive members  210   b  respectively corresponding thereto so as to be substantially symmetrical with respect to the center axis of the region where the lens openings  204  are provided. 
     As shown in FIG. 16C, the first sub-magnetic conductive members  240   a  may be provided on a face of the first lens magnetic conductive member  210   a  that is opposed to the second lens magnetic conductive member  210   b , while the second sub-magnetic conductive members  240   b  are provided on a face of the second lens magnetic conductive member  210   b  that is opposed to the first lens magnetic member  210   a . In this case, it is preferable that each opening formed by the first and second sub-magnetic conductive members  240   a  and  240   b  are substantially the same as the corresponding openings in the first and second lens magnetic conductive member  210   a  and  210   b.    
     FIGS. 17A and 17B show an example of the lens-intensity adjuster that can adjust the lens intensity of the multi-axis electron lens. The first, second, third and fourth lens-intensity controllers  17 ,  25 ,  35  and  37  may have the same structure and functions. The first lens-intensity adjuster  17  is described as a typical example in the following description. 
     FIG. 17A is a cross-sectional view of the first lens-intensity adjuster  17  and the lens part  202  included in the multi-axis electron lens. The first lens-intensity adjuster  17  includes a substrate  530  arranged substantially parallel to the multi-axis electron lens and adjusting electrodes  532  provided on the substrate  530 . The adjusting electrodes  532  are an example of a lens-intensity adjuster for adjusting the lens intensity of the multi-axis electron lens. 
     The first lens-intensity adjuster  17  generates a desired electric field by applying a predetermined voltage to the adjusting electrode  532 , so that the speed of the electron beam that is to enter the lens opening  204  can be increased or reduced. The electron beam entering the lens opening  204  after the speed thereof has been reduced requires a longer time period for passing through the lens opening  204 , as compared to the electron beam entering the lens opening  204  without being decelerated. In other words, the lens intensity applied by the magnetic field formed in the lens opening  204  to the electron beam incident thereon can be adjusted. Therefore, since the electron beam has been affected by the magnetic field formed in the lens opening  204  by the first and second lens magnetic conductive members  210   a  and  210   b  for a longer time period than the electron beam entering the lens opening  204  without being decelerated or the electron beam incident on the other lens opening  204 , the position of the focal point of the electron beam and the rotation of the exposed image of the electron beam can be adjusted. When the adjusting electrode  532  is provided for each lens opening  204 , the adjustment of the position of the focal point, the adjustment of the rotation of the exposed image or the like can be performed for each electron beam independently of other electron beams. 
     It is desirable to provide the adjusting electrodes  532  to be electrically insulated from the lens magnetic conductive members  210   a  and  210   b  from the substrate  530  to the lens opening  204 . In this example, the adjusting electrodes  532  are cylindrical electrodes each of which is provided to surround the electron beam passing thorough the lens opening  204 . In addition, in this example, the substrate  530  is arranged between the multi-axis electron lens and the electron beam generator  10  that generates the electron beams, so as to be opposed to the second lens magnetic conductive member  210   b . The length of the adjusting electrode  532  in a direction along the direction in which the electron beams are emitted is set to be longer than the inner diameter of the adjusting electrode  532 . Also, the substrate  530  is provided to project from the first lens magnetic conductive member  210   a  that is different from the second lens magnetic conductive member  210   b  towards the direction in which the electron beams are emitted. In an alternative example, the substrate  530  may be provided between the multi-axis electron lens and the wafer  44  to be opposed to the first lens magnetic conductive member  210   a.    
     FIG. 17B is a top view of a surface of the first lens-intensity adjuster  17  on which the adjusting electrodes  532  are provided. The first lens-intensity adjuster  17  further includes an adjusting electrode controller  536  that can apply desired voltages to the adjusting electrodes  532 . It is desirable that the adjusting electrodes  532  are electrically connected to the adjusting electrode controller  536  via wirings  538  provided on the substrate  530 . Moreover, it is preferable that the first lens-intensity adjuster  17  includes a plurality of adjusting electrode controllers  536  for applying the adjusting electrodes  532 , respectively. The adjusting electrodes  532  may have a multi-electrode structure in which the electrodes can form an electric field in a direction substantially perpendicular to the direction in which the electron beams are emitted. For example, the adjusting electrode  532  has eight electrodes opposed to each other, as shown in FIG.  8 A. In this case, it is preferable that the first lens-intensity adjuster  17  further includes a means operable to apply different voltages to the respective electrodes included in the multi-electrode structure of the adjusting electrode  532 . By applying the different voltages to the respective electrodes of the adjusting electrode  532 , astigmatism correction and/or deflection of the electron beam can be realized. Furthermore, a shift of the focal point caused by the deflected position and/or the cross-sectional size of the electron beam can be corrected. 
     FIGS. 18A and 18B show another exemplary lens-intensity adjuster that can adjust the lens intensity of the multi-axis electron lens. FIG. 18A is a cross-sectional view of the first lens-intensity adjuster  17  and the lens part  202  of the multi-axis electron lens. The first lens-intensity adjuster  17  includes a substrate  540  arranged substantially parallel to the multi-axis electron lens and adjusting coils  542  provided on the substrate  540  as an example of the lens-intensity adjuster for adjusting the lens intensity of the multi-axis electron lens. The first lens-intensity adjuster  17  generates desired electric fields by supplying predetermined currents to the adjusting electrodes  542 , thereby making it possible to adjust the intensities of the magnetic fields formed in the lens openings  204  by the first and second lens magnetic conductive members  210   a  and  210   b . Thus, the lens intensity applied to the electron beam incident on the lens opening  204  by the magnetic field formed in that lens opening  204  can be adjusted. Then, since the electron beam entering the lens opening  204  is affected both by the magnetic field formed by the first and second lens magnetic conductive members  210   a  and  210   b  and the magnetic field formed by the adjusting coil  542 , the focus position of the electron beam and the rotation of the exposed image can be adjusted. Furthermore, the adjustment of the focus position and the adjustment of the rotation of the exposed image can be performed for the each of the electron beams passing through the respective lens openings  204  by providing the adjusting coil  542  in each of the lens openings  204 . 
     It is desirable to arrange the adjusting coil  542  to be electrically insulated from the lens magnetic conductive members  210   a  and  210   b  from the substrate  540  to the lens opening  204 . The adjusting coil  542  of this example is a solenoid coil provided to surround the electron beam passing through the corresponding lens opening  204 . Moreover, in this example, the substrate  540  is provided between the multi-axis electron lens and the electron beam generator  10  so as to be opposed to the second lens magnetic conductive member  210   b  and to project from the first lens magnetic conductive member  210   a  differently from the second lens magnetic conductive member  210   b  toward the direction in which the electron beams are radiated. In an alternative example, the adjusting coil  542  maybe provided in the outside of the corresponding lens opening  204  to surround the optical axis of the electron beam passing through the lens opening  204  so that the magnetic field formed in the lens opening  204  is affected by the adjusting coil  542 . Furthermore, the first lens-intensity adjuster  17  may include a radiation member, provided in the vicinity of the adjusting coil  542  or in contact with the adjusting coil  542 , for inducing heat generated in the adjusting coil  542 . The radiation member may be a cylindrical non-magnetic conductive member, for example. Also, the radiation member may be arranged in the surrounding area of the adjusting coil  542 . 
     FIG. 18B is a top view of the surface of the first lens-intensity adjuster  17  on which the adjusting coils  542  are provided. The first lens-intensity adjuster  17  further includes an adjusting coil controller  546  for supplying desired currents to the respective adjusting coils  542 . It is desirable that the adjusting coils  542  are electrically connected to the adjusting coil controller  546  via wirings  548  provided on the substrate  540 . Moreover, it is preferable that the first lens-intensity adjuster  17  includes a plurality of adjusting coil controllers  546  each of which independently applies a voltage to a corresponding one of the adjusting coils  542 . 
     FIGS. 19A and 19B show an exemplary arrangement of the first shaping-deflecting unit  18  and the blocking unit  600 . FIG. 19A is a cross-sectional view of the first shaping-deflecting unit  18  and the blocking unit  600 , while FIG. 19B is a top view thereof. Although the first shaping-deflecting unit  18  is described as an example in the following description, the second shaping-deflecting unit  20  and the blanking electrode array  26  can have the same arrangement as the first shaping-deflecting unit  18 . 
     The first shaping-deflecting unit  18  includes a substrate  186  provided to be substantially perpendicular to the direction in which the electron beams are emitted, openings  194  provided in the substrate  186 , deflectors  190  respectively provided in the openings  194  along the direction in which the electron beams are emitted, as shown in FIG.  19 A. The blocking unit  600  includes a first blocking substrate  602  and a second blocking substrate  608  provided to be substantially perpendicular to the direction in which the electron beams are emitted, first blocking electrodes  604  provided on the first blocking substrate  602  along the direction in which the electron beams are emitted, and second blocking electrodes  610  provided on the second blocking substrate  608  along the direction in which the electron beams are emitted. The first and second blocking substrate  602  and  608  are arranged to be opposed to each other with the substrate  186  of the first shaping-deflecting unit  18  interposed there-between. 
     The first blocking electrodes  604  are preferably arranged between the deflectors  190  so as to extend along the direction in which the electron beams are emitted from a position closer to the electron beam generator  10  (shown in FIG. 1) than the end of the deflector  190  that is closer to the electron beam generator  10  to a position closer to the wafer  44  (shown in FIG. 1) than the other end of the deflector  190 . It is also preferable that the first blocking electrodes  604  are grounded. Moreover, the second blocking electrodes  610  are preferably arranged to be opposed to the first blocking electrodes  604  with the substrate  186  sandwiched there-between so as to extend along the direction in which the electron beams are emitted. Also, it is preferable to ground the second blocking electrodes  610 . Furthermore, as shown in FIG. 19B, the first and second blocking electrodes  604  and  610  are preferably arranged to form a lattice between the deflectors  190 . 
     FIG. 20 shows an exemplary specific arrangement of the first and second blocking electrodes  604  and  610 . It is preferable that the first and second blocking electrodes  604  and  610  have a plurality of holes each of which opens substantially perpendicular to the direction in which the electron beams are emitted. It is more preferable that the first and second blocking electrodes  604  and  610  are meshes, as shown in FIG.  20 . By providing the first and second blocking electrodes  604  and  610  arranged in the body  8  with the holes, interference between each of the electron beams and the electric fields generated for other electron beams can be prevented without reducing the conductance of exhaustion in a case where the body  8  is exhausted to vacuum via the exhaustion holes  708 , thereby the electron beams can be made incident on the wafer  44  with high precision. 
     FIGS. 21A and 21B show another example of the first shaping-deflecting unit  18  and the blocking unit  600 . FIG. 21A is a cross-sectional view of the first shaping-deflecting unit  18  and the blocking unit  600  while FIG. 21B is a view thereof seen from a wafer-side. 
     The blocking unit  600  includes the substrate  602  and a plurality of blocking electrodes  606 . As shown in FIGS. 21A and 21B, the blocking electrodes  606  maybe arranged to be cylindrical in the are as surrounding the respective deflectors  190 . It should be noted the blocking electrodes  606  can have any shape as long as the electric field generated by a particular first shaping-deflecting unit  18  can be blocked from the electric fields generated by the other first shaping-deflecting units  18  so that the electric field generated by the particular first shaping-deflecting unit  18  cannot affect the electron beams other than the corresponding electron beam. 
     FIG. 22 shows another exemplary arrangement of the first shaping-deflecting unit  18 . As shown in FIG. 22, the first shaping-deflecting unit  18  of this example includes a substrate  186  provided to be substantially perpendicular to the direction in which the electron beams are emitted, openings  194  provided in the substrate  186 , deflectors  190  provided for the respective openings  194 , first blocking electrodes  604  provided between adjacent openings  194  and second blocking electrodes  610  provided to be opposed to the first blocking electrodes  604  with the substrate  186  sandwiched there-between so as to extend along a direction substantially perpendicular to the substrate  186 . 
     The deflectors  190  are arranged along the first direction substantially perpendicular to the substrate  186 . The first blocking electrodes  604  are preferably arranged along the first direction so as to extend longer than the deflectors  190 . The first and second blocking electrodes  604  and  610  may be arranged to form a lattice between the openings  194 . Moreover, the first and second blocking electrodes  604  and  610  may have holes arranged in a direction substantially perpendicular to the substrate  186 . In this case, it is preferable that the first and second blocking electrodes  604  and  610  are meshes. Furthermore, the first and second blocking electrodes  604  and  610  are arranged at any position as long as the first and second blocking electrodes  604  and  610  are arranged between the openings  194  on the lower surface and the upper surface of the substrate  186 , respectively. 
     FIGS. 23A and 23B show an exemplary arrangement of the deflecting unit  60 , the fifth multi-axis electron lens  62  and a blocking unit  900 . As shown in FIG. 23A, the deflecting unit  60  includes a substrate  186  and a plurality of deflectors  190  respectively provided in the lens openings of the fifth multi-axis electron lens  62 . The fifth multi-axis electron lens  62  includes the first magnetic conductive member  210   b  having a plurality of first openings allowing electron beams passing there-through and the second magnetic conductive member  210   a  having a plurality of second openings allowing the electron beams that have passed through the first openings to pass there-through. The first and second magnetic conductive members  210   b  and  210   a  are arranged to be substantially parallel to each other. The blocking unit  900  includes first blocking electrodes  902  provided to extend in a direction from the first magnetic conductive member  210   b  toward the electron beam generator  10 , a first blocking substrate  904  provided to be substantially parallel to the first magnetic conductive member  210   b  for holding the first blocking electrodes  902 , second blocking electrodes  910  provided to extend in a direction from the second magnetic conductive member  210   a  toward the wafer  44 , a second blocking substrate  908  provided to be substantially parallel to the second magnetic conductive member  210   a  for holding the second blocking electrodes  910 , and third blocking electrodes  906  provided between the first and second magnetic conductive members  210   b  and  210   a , as shown in FIG.  23 A. 
     The first, second and third blocking electrodes  902 ,  910  and  906  maybe arranged to form a lattice between the lens openings. Also, the first, second and third blocking electrodes  902 ,  910  and  906  may be provided in the surrounding are as of the lens openings. Moreover, the first, second and third blocking electrodes  902 ,  910  and  906  may have holes arranged in a direction substantially perpendicular to the substrate  186 . In this case, it is preferable that the first, second and third blocking electrodes  902 ,  910  and  906  are formed by meshes. In addition, the blocking unit  900  may include no first blocking substrate  904 . In this case, the first blocking electrodes  902  can be held by the substrate  186 . Similarly, the blocking unit  900  may include no second blocking substrate  908 . In this case, the second blocking electrodes  910  can be held by the second magnetic conductive member  210   a . Furthermore, the blocking unit  900  may not include the second blocking electrode  910  in a case where the deflectors  190  do not project from the second magnetic conductive member  210   a  towards the wafer  44 , as shown in FIG.  23 B. 
     FIG. 24 shows the electric field blocked by the blocking unit  600  or  900 . In FIG. 24, the electric field generated by the deflectors  190  in the first shaping-deflecting unit  18  as an example is shown. When the blocking electrodes are provided between the electrodes of the adjacent deflectors  190 , the effects of the electric field generated by a particular deflector  190  on the electron beams other than the corresponding electron beam to be deflected by the particular deflector  190  can be greatly reduced. 
     As a specific example, a case is considered where a negative voltage is applied to the deflecting electrode of the deflector  190   a  in order to deflect the electron beam passing through the opening  194   a , a positive voltage is applied to the deflecting electrode of the deflector  190   c  in order to deflect the electron beam passing through the opening  194   c  and no voltage is applied to the deflecting electrode of the deflector  190   b  in order to allow the electron beam to pass straight through the opening  194   b . In this case, as shown in FIG. 24, the first and second blocking electrodes  604  and  610  can block the electric fields generated by the deflectors  190   a  and  190   c  so as to greatly reduce the effects of the deflectors  190   a  and  190   c  on the electron beam passing through the deflector  190   b . Therefore, a plurality of electron beams can be cast onto the wafer  44  with high precision. 
     FIG. 25 shows an example of the first and second shaping members  14  and  22 . The first shaping member  14  has a plurality of illumination areas  560  that are to be illuminated with electron beams generated by the electron beam generator  10 , respectively. The first shaping member  14  includes a first shaping opening in each illumination area  560  so as to shape the electron beam incident thereon. It is preferable that the first shaping openings have rectangular shapes. 
     Similarly, the second shaping member  22  has a plurality of illumination areas  560  to be illuminated with the electron beams after being deflected by the first and second shaping-deflecting units  18  and  20 . The second shaping member  22  includes a second shaping opening in each illumination area  560  so as to shape the electron beam incident thereon. It is preferable that the second shaping openings have rectangular shapes. 
     FIG. 26A shows another example of the illumination areas  560  in the second shaping member  22 . As shown in FIG. 26A, the illumination area  560  includes the second shaping opening  562  described referring to FIG. 25 and a plurality of pattern-opening areas  564  where pattern openings having different shapes from the second shaping opening  562  are provided. It is preferable that the pattern-opening area  564  has a size that is substantially the same as or less than the maximum size of the electron beam shaped by the first shaping member  14 . It is also preferable that the shape of the pattern-opening area  564  is the same as or similar to the cross-sectional shape of the electron beam shaped by the first shaping member  14 . 
     FIGS. 26B,  26 C,  26 D and  26 E show exemplary pattern openings  566 . As shown in FIGS. 26B and 26C, it is preferable that the pattern openings  566  are openings for exposing openings to be provided at a constant interval or a constant period, such as contact holes for electrically connecting transistors to be formed on the wafer to wirings or through holes for electrically connecting the wirings to each other. The pattern openings  566  may be openings for exposing a line and space pattern provided at a constant interval or a constant period, such as gate electrodes of the transistors or the wirings, as shown in FIGS. 26D and 26E. 
     When each of the electron beams shaped in the first shaping member  14  is incident entirely on the pattern-opening area  564  of the illumination area  560  corresponding to the electron beam, a pattern to be formed by electron beams after passing through the pattern openings  566  included in the pattern-opening area  564  is exposed at once. 
     FIG. 27 shows an exemplary arrangement of the controlling system  140  described before referring to FIG.  1 . The controlling system  140  includes the general controller  130 , the individual controller  120 , the multi-axis electron lens controller  82  and the wafer-stage controller  96 . The general controller  130  includes a central processing unit  220  for controlling the controlling system  140 , an exposure pattern storing unit  224  for storing an exposure pattern to be exposed onto the wafer  44 , an exposure data generating unit  222  for generating exposure data that is an exposure pattern in an area to be exposed by the electron beams based on the exposure pattern stored in the exposure pattern storing unit  224 , an exposure data memory  226  that is a memory for the exposure data, an exposure data sharing unit  228  for allowing the exposure data to be shared with other controllers, and a position information calculating unit  230  for calculating the exposure data and position information of the wafer stage  46 . 
     The individual controller  120  includes the electron beam controller  80  for controlling the electron beam generator  10 , the shaping-deflector controller  84  for controlling the shaping-deflecting units  18  and  20 , the lens-intensity controller  88  for controlling the lens-intensity adjusters  17 ,  25 ,  35  and  37 , the blanking electrode array controller  86  for controlling the blanking electrode array  26 , and the deflector controller  98  for controlling deflecting unit  60 . The multi-axis electron lens controller  82  controls currents to be supplied to the coils in the multi-axis electron lenses  16 ,  24 ,  34 ,  36  and  62  in accordance with an instruction from the central processing unit  20 . 
     The operation of the controlling system  140  in this example is described below. Based on the exposure pattern stored in the exposure pattern storing unit  224 , the exposure data generating unit  222  generates the exposure data and stores the generated exposure data in the exposure data memory  226 . The exposure data sharing unit  228  reads the exposure data stored from the exposure data memory  226 , stores it therein, and supplies it to the position information calculating unit  230  and an individual controller  120 . The exposure data memory  226  is preferably a buffer memory for temporarily storing the exposure data. More specifically, it is preferable that the buffer memory as the exposure data memory  226  stores the exposure data corresponding to an area to be exposed next. The individual electron beam controller  122  controls each of the electron beams based on the received exposure data. The position information calculating unit  230  supplies information used for adjusting a position to which the wafer stage  46  is to move to the wafer-stage controller  96  based on the received exposure data. The wafer-stage controller  96  then controls the wafer-stage driving unit  48  to move the wafer stage  46  to a predetermined position based on the information from the position information calculating unit  230  and an instruction from the central processing unit  220 . 
     FIG. 28 shows details of the components included in the individual controlling system  120 . The blanking electrode array controller  86  includes individual blanking electrode controllers  126  each of which generates a reference clock and controls, for a corresponding one of t electron beams, whether or not a voltage is applied to the deflecting electrode  168  corresponding to the electron beam in accordance with the reference clock based on the received exposure data, and amplifying parts  146  that amplify signals output from the individual blanking electrode controllers  126  so as to output the amplified signals to the blanking electrode array  26 . 
     The shaping-deflector controller  84  includes a plurality of individual shaping-deflector controllers  124  for outputting a plurality of units of voltage data indicating voltages to be applied to the deflecting electrodes of the shaping-deflecting units  18  and  20 , respectively, digital-analog converters (DAC)  134  for converting the voltage data units received from the individual shaping-deflector controllers  124  in digital data form into analog data so as to output the analog data, and amplifying parts  144  each amplifies the analog data received from the corresponding DAC  134  to supply the amplified analog data to the shaping-deflecting unit  18  or  20 . 
     The lens-intensity controller  88  includes individual lens-intensity controllers  125  for respectively outputting a plurality of data units used for controlling voltages to be applied to the lens-intensity adjusters  17 ,  25 ,  35  and  37  or currents to be supplied thereto, Daces  135  each of which converts the data unit received from the corresponding individual lens-intensity controller  124  into analog data, and amplifying parts  145  each of which amplifies the analog data received from the corresponding DAC  135  to supply the amplified analog data to the shaping-deflecting unit  18  or  20 . 
     The lens-intensity controller  88  controls the voltages to be applied to the respective lens-intensity adjusters  17 ,  25 ,  35  and  37  and/or the currents to be supplied thereto so as to make the lens intensities in the lens openings  204  in each of the multi-axis electron lenses substantially uniform based on the instruction from the central processing unit  220 . In this example, the lens-intensity controller  88  supplies a constant voltage and/or current to each of the lens-intensity adjuster  17 ,  25 ,  35  or  37  in the exposure process. In this case, the lens-intensity controller  88  controls each of the lens-intensity adjuster  17 ,  25 ,  35  or  37  based on data for calibrating the focus and/or rotation of each electron beam with respect to the wafer  44  obtained prior to the exposure process. That is, the lens-intensity controller  88  may control the respective lens-intensity adjusters  17 ,  25 ,  35  and  37  in the exposure process without using the exposure data. 
     The deflector controller  98  includes individual deflector controllers  128  for respectively outputting a plurality of units of voltage data indicating voltages to be applied to the deflecting electrodes of the deflecting unit  60 , Daces  138  each of which converts one of the voltage data units received as digital data from the corresponding individual deflector controller  128  into analog data so as to output the analog data, and AMPs  148  each of which amplifies the analog data received from the corresponding DAC  138  to supply the amplified analog data to the deflecting unit  60 . It is desirable that the deflector controller  98  includes the individual deflector controller  122 , the DAC  138  and the AMP  148  for each of the deflecting electrodes included in the deflecting unit  60 . 
     The operations of the deflector controller  84 , the blanking electrode array controller  86 , and the deflector controller  98  are described. First, the individual blanking electrode controllers  126  determine times at which the voltages are applied to the respective deflecting electrodes  168  of the blanking electrode array  26  based on the exposure data and the reference clock. In this example, the individual blanking electrode controllers  126  control each of the electron beams whether or not the electron beam is cast onto the wafer  44  at a different time from the time of the other electron beams. In other words, each individual blanking electrode controller  126  generates the time at which the electron beam is cast onto the wafer  44  independently of the time for the other electron beam, and controls whether or not the corresponding electron beam passing through the blanking electrode array  26  is to be cast onto the wafer  44  at the generated time. It is preferable the individual blanking electrode controller  126  determines a time period for which the wafer  44  is illuminated with the corresponding electron beam based on the received exposure data and the reference clock. 
     In accordance with the times generated by the individual blanking electrode controllers  126 , the individual shaping-deflector controllers  124  output voltages to be applied to the deflecting electrodes of the shaping-deflecting units  18  and  20  in order to shape the cross-sectional shapes of the electron beams based on the received exposure data. Also in accordance with the times generated by the individual blanking electrode controllers  126 , the individual deflectors  128  output a plurality of voltage data units specifying voltages to be applied to the deflecting electrodes of the deflecting unit  60  based on the received exposure data in order to control the electron beams to be positioned at positions on the wafer  44  to be illuminated with the electron beams, respectively. 
     FIG. 29 shows an example of the backscattered electron detector  50 . The backscattered electron detector  50  includes a substrate  702  having a plurality of openings  704  allowing a plurality of electron beams to pass there-through, respectively, and electron detectors  700  for detecting electrons radiated from marked portions (not shown) provided on the wafer  44  or the wafer stage  46  so as to output a detection signal based on the amount of the detected electrons. The electron detectors  700  of this example are provided between the openings  704  provided in the substrate  702 . That is, the electron detectors  700  are arranged between two electron beams passing through the adjacent two openings  704 . 
     The electron detectors  700  are preferably arranged in such a manner that each electron detector  700  is positioned on substantially the same line as the optical axes of the two electron beams passing through the two openings  704  adjacent to the electron beam detector  700 . Moreover, it is desirable that the electron beam generator  10  generates three or more electron beams with a substantially constant interval while the electron detectors  700  are provided between the three or more electron beams passing through the three or more openings  704 . Also, the openings  704  are preferably arranged to form a lattice. In this case, it is desirable that the electron beam detectors  700  are arranged between the openings  704  of the lattice. Furthermore, the electron beam detector  700  may be provided on the outer side of the openings  704  arranged at the outermost positions. 
     FIG. 30 shows another exemplary arrangement of the backscattered electron detector  50 . The backscattered electron detector  50  includes a substrate  702  having a plurality of openings  704  allowing a plurality of electron beams to pass there-through, respectively, and electron detectors  700  for detecting electrons radiated from a target mark (not shown) on the wafer  44  or the wafer stage  46  so as to output a detection signal based on the amount of the detected electrons. The electron detectors  700  of this example are arranged in such a manner that two or more of the electron detectors  700  are positioned between the adjacent openings  704 . In other words, two or more the electron detectors  700  are arranged between the two electron beams passing through the two openings  704  so as to correspond to the two openings  704 , respectively. Moreover, the electron detectors  700  are arranged in the surrounding area of each of the openings  704 . 
     It is preferable that the two or more electron detectors  700  are provided on substantially the same line as the optical axes of the two electron beams passing through the two openings  704  adjacent to these electron detectors  700 . Moreover, it is desirable that the electron beam generator  10  generates three or more electron beams at a substantially constant interval. In this case, the electron detectors  700  are desirably arranged in such a manner that two or more of the electron detectors  700  are positioned between the three or more electron beams passing through the three or more openings  704 , respectively. In addition, the openings  704  are preferably arranged to form a lattice between which the electron detectors  700  are arranged in such a manner that two or more electron detectors  700  are positioned between the adjacent openings  704 . Furthermore, the electron detectors  700  may be provided on the outer side of the outermost openings  704 . 
     FIG. 31 shows another exemplary backscattered electron detector  50 . The backscattered electron detector  50  includes a substrate  702  having a plurality of openings  704  allowing a plurality of electron beams to pass there-through, respectively, electron detectors  700  for detecting the electrons radiated from the target mark (not shown) provided on the wafer  44  or the wafer stage  46  to output a detection signal based on the amount of the detected electrons, and blocking plates  706  provided between the openings  704 . The electron detectors  700  of this example are arranged in such a manner that two or more electron detectors  700  are positioned between the adjacent openings  704  so as to respectively correspond the openings  704 . 
     It is preferable that the electron detectors  700  are further provided in areas surrounding each of the openings  704  provided on the substrate  702 . Moreover, the blocking plates  706  are preferably provided between a particular electron beam and the electron beams adjacent to the particular electron beam. That is, the blocking plates  706  are provided between the electron detectors provided in the surrounding area of a particular opening  704  and the electron detectors provided in the surrounding area of the opening  704  adjacent to the particular opening  704 . 
     The blocking plates  706  are arranged at any portions as long as each blocking plate  706  is positioned between the electron beam and the electron detector  700  that is corresponding thereto. It is preferable that the blocking plate  706  is provided between the illumination position of the electron beam in a surface onto which the wafer is to be placed and the electron detector provided in the second electron beam. It is also desirable that the blocking plates  706  are formed from non-magnetic conductive material. Moreover, it is desirable that the blocking plates  706  are grounded by being electrically connected to the substrate  702 . 
     FIG. 32 shows still another exemplary arrangement of the backscattered electron detector  50 . The blocking plates  708  may be arranged to form a lattice between the electron detectors  700  provided in the surrounding areas of the openings  704  that are also arranged to form a lattice. The blocking plates  708  may have any shapes as long as each blocking plate  708  blocks a predetermined electron detector  700  from other electron detectors  700  so as to avoid the radiation of the electrons from a predetermined target mark (not shown) to electron detectors other than a predetermined electron detector that corresponds to the predetermined marked portion. 
     FIG. 33 shows an electron beam exposure apparatus  100  according to another embodiment of the present invention. In the present embodiment, each electron beam is provided to be away from electron beams adjacent thereto by narrower distances. The distance between the adjacent electron beams may be set to be such a distance that all the electron beams are incident on an area corresponding to one chip to be provided on the wafer, for example. The components labeled with the same reference numerals in FIG. 33 as those in FIG. 1 may have the same structures and functions as the components of the electron beam exposure apparatus shown in FIG.  1 . In the following description, structures, operations and functions of the electron beam exposure apparatus of the present embodiment that are different from those of the electron beam exposure apparatus shown in FIG. 1 are described. 
     The electron beam shaping unit includes an electron beam generator  10  which can generate a plurality of electron beams, an anode  13  which allows the generated electron beams to be radiated, a slit cover  11  having a plurality of openings for shaping the cross-sectional shapes of the electron beams by allowing the electron beams to pass there-through, respectively, a first shaping member  14 , a second shaping member  22 , a first multi-axis electron lens  16  which can converge the electron beams independently of each other to adjust focal points of the electron beams, a slit-deflecting unit  15  that can deflect the electron beams after passing through the anode  13  independently of each other, and first and second shaping-deflecting units  18  and  20  which can deflect the electron beams after passing through the first shaping member  14 . 
     It is desirable that the slit cover  11  and the first and the second shaping members  14  and  22  have grounded metal films such as platinum films, on surfaces thereof onto which the electron beams are incident. It is also desirable that each of the slit cover  11  and the first and second shaping members  14  and  22  includes a cooling unit for suppressing the increase in the temperature caused by the incident electron beams. 
     The openings included in each of the slit cover  11  and the first and second shaping members  14  and  22  may have cross-sectional shapes each of which becomes wider along the radiated direction of the electron beams in order to allow the electron beams to pass efficiently. Moreover, the openings of each of the slit cover  11  and the first and second shaping members  14  and  22  are preferably formed to be rectangular. 
     The illumination switching unit includes: a second multi-axis electron lens  24  which can converge a plurality of electron beams independently of each other to adjust focal points thereof; a blanking electrode array  26  which switches for each of the electron beams whether or not the electron beam is to be incident on the wafer  44 ; and an electron beam blocking member  28  that has a plurality of openings allowing the electron beams to pass there-through, respectively, and can block the electron beams deflected by the blanking electrode array  26 . The openings of the electron beam blocking member  28  may have cross-sectional shapes each of which becomes wider along the radiated direction of the electron beams in order to allow the electron beams to efficiently pass there-through. 
     The wafer projection system includes: a third multi-axis electron lens  34  which can converge a plurality of electron beams independently of each other and adjust the rotations of the electron beams to be incident onto the wafer  44 ; a fourth multi-axis electron lens  36  which can converge a plurality of electron beams independently of each other and adjust the reduction ratio of each electron beam to be incident onto the wafer  44 ; a sub-deflecting unit  38  that is an independent deflecting unit for deflecting a plurality of electron beams independently of each other towards desired positions on the wafer  44 ; a coaxial lens  52  which can function as an objective lens and has a first coil  40  and a second coil  54  for converging a plurality of electron beams independently of each other; and a main deflecting unit  42  that is a common deflecting unit for deflecting a plurality of electron beams towards substantially the same direction by desired amounts. The sub-deflecting unit  38  may be provided between the first coil  54  and the second coil  40 . 
     The main deflecting unit  42  is preferably an electrostatic type deflector that can deflect a plurality of electron beams at high speed by using an electric field. More preferably, the main deflecting unit  42  has a cylindrical eight-electrode structure having four pairs of electrodes in which the electrodes of each pair are opposed to each other, or a structure including eight or more electrodes. Moreover, it is preferable that the coaxial lens  52  is provided to be closer to the wafer  44  than the multi-axis electron lens. In addition, although the third multi-axis electron lens  34  and the fourth multi-axis electron lens  36  are integrated with each other in this example, these lenses may be formed separately in an alternative example. 
     The controlling system  140  includes a general controller  130 , a multi-axis electron lens controller  82 , a coaxial lens controller  90 , a main deflector controller  94 , a backscattered electron processing unit  99 , a wafer-stage controller  96  and an individual controller  120  which can control exposure parameters for each of the electron beams. The general controller  130  is, for example, a work station and can control the respective controllers included in the individual controller  120 . The multi-axis electron lens controller  82  controls currents to be respectively supplied to the first multi-axis electron lens  16 , the second multi-axis electron lens  24 , the third multi-axis electron lens  34  and the fourth multi-axis electron lens  36 . The coaxial electron lens controller  90  controls the number of currents to be supplied to the first and second coils  40  and  54  of the coaxial lens  52 . The main deflector controller  94  controls a voltage to be applied to the main deflector  42 . The backscattered electron processing unit  99  receives a signal based on the amount of backscattered electrons or secondary electrons detected in a backscattered electron detector  50  and notify the general controller  130  that the backscattered electron processing unit  99  received the signal. The wafer-stage controller  96  controls the wafer-stage driving unit  48  so as to move the wafer stage  46  to a predetermined position. 
     The individual controller  120  includes an electron beam controller  80  for controlling the electron beam generator  10 , a shaping-deflector controller  84  for controlling the first and second shaping-deflecting units  18  and  20 , a blanking electrode array controller  86  for controlling voltages to be applied to deflection electrodes included in the blanking electrode array  26 , and a sub-deflector controller  98  for controlling voltages to be applied to electrodes included in the deflectors of the sub-deflecting unit  38 . 
     Next, the operation of the electron beam exposure apparatus  100  in the present embodiment is described. First, the electron beam generator  10  generates a plurality of electron beams. The generated electron beams pass through the anode  13  to enter the slit-deflecting unit  15 . The slit-deflecting unit  15  adjusts the incident positions on the slit cover  11  onto which the electron beams after passing through the anode  13  are incident. 
     The slit cover  11  can block a part of each electron beam so as to reduce the area of the electron beam to be incident on the first shaping member  14 , thereby shaping the cross section of the electron beam to have a predetermined size. The thus shaped electron beams are then incident on the first shaping member  14  that further shapes the electron beams. Each of the electron beams after passing through the first shaping member  14  has a rectangular cross section in accordance with a corresponding one of the openings included in the first shaping member  14 . The electron beams after passing through the first shaping member  14  are converged by the first multi-axis electron lens  16  independently of each other, so that for each of the electron beams the focus adjustment of the electron beam with respect to the second shaping member  22  is performed. 
     The first shaping-deflecting unit  18  deflects each of the electron beams having the rectangular cross sections independently of the other electron beams in order to make the electron beams incident on desired positions on the second shaping member  22 . The second shaping-deflecting unit  20  further deflects the thus deflected electron beams independently of each other towards a direction approximately perpendicular to the second shaping member  22 , thereby performing such an adjustment that the electron beams are incident on the desired positions of the second shaping member  22  approximately perpendicular to the second shaping member  22 . The second shaping member  22  having a plurality of rectangular openings further shapes the electron beams incident thereon in such a manner that the electron beams have desired rectangular cross sections, respectively, when being incident on the wafer  44 . 
     The second multi-axis electron lens  24  converges a plurality of electron beams independently of each other to perform the focus adjustment of the electron beam with respect to the blanking electrode array  26  for each electron beam. The electron beams that have been subjected to the focus adjustment by the second multi-axis electron lens  24  pass through a plurality of apertures of the blanking electrode array  26 . 
     The blanking electrode array controller  86  controls whether or not voltages are applied to deflection electrodes provided in the vicinity of the respective apertures of the blanking electrode array  26 . Based on the voltages applied to the deflection electrodes, the blanking electrode array  26  switches for each of the electron beams whether or not the electron beam is made incident on the wafer  44 . When the voltage is applied, the electron beam passing through the corresponding aperture is deflected. Thus, the electron beam cannot pass through a corresponding opening of the electron beam blocking member  28 , so that it cannot be incident on the wafer  44 . When the voltage is not applied, the electron beam passing through the corresponding aperture is not deflected, so that it can pass through the corresponding opening of the electron beam blocking member  28 . Thus, the electron beam can be incident on the wafer  44 . 
     The third multi-axis electron lens  34  adjusts the rotation of the image of the electron beam to be incident on the wafer  44 , which has not been deflected by the blanking electrode array  26 . The fourth multi-axis electron lens  36  reduces the illumination diameter of each of the electron beams incident thereon. Among the electron beams that have passed through the third multi-axis electron lens  34  and the fourth multi-axis electron lens  36 , only the electron beam to be incident onto the wafer  44  passes through the electron beam blocking member  28  so as to enter the sub-deflecting unit  38 . 
     The sub-deflector controller  98  controls a plurality of deflectors included in the sub-deflecting unit  38  independently of each other. The sub-deflecting unit  38  deflects the electron beams incident on the deflectors independently of each other in such a manner that the deflected electron beams are incident on the desired positions on the wafer  44 . The electron beams that have passed through the sub-deflecting unit  38  are subjected to the focus adjustment with respect to the wafer  44  by the coaxial lens  52  having the first and second coils  40  and  54 , so as to be incident on the wafer  44 . 
     During the exposure process, the wafer-stage controller  96  moves the wafer stage  48  in predetermined directions. The blanking electrode array controller  86  determines the apertures that allow the electron beams to pass and performs an electric-power control for the respective apertures based on exposure pattern data. By changing the apertures allowing the electron beams to pass there-through in accordance with the movement of the wafer  44  and then further deflecting the electron beams by the main deflecting unit  42  and the sub-deflecting unit  38 , a desired circuit pattern can be transferred by exposing the wafer  44 . The method for illuminating the wafer with the electron beams is described later referring to FIGS. 37,  38 A and  38 B. 
     The electron beam exposure apparatus  100  of the present embodiment converges a plurality of electron beams independently of each other. Thus, although a cross over is formed for each electron beam, all the electron beams as a whole do not have its cross over. Therefore, even in a case where the current density of each electron beam is increased, the electron beam error that may cause a shift of the focus or position of the electron beam due to coulomb interaction can be greatly reduced. 
     FIGS. 34A and 34B show an exemplary arrangement of the electron beam generator  10  shown in FIG.  33 . FIG. 34A is a cross-sectional view of the electron beam generator  10 . In this example, the electron beam generator  10  includes an insulator  106 , cathodes  12  formed from material that can radiate thermoelectrons, such as tungsten or lanthanum hexaborane, grids  102  formed to surround the cathodes  12 , respectively, a cathode wiring  500  for supplying currents to the cathodes  12 , grid wirings  502  for applying voltages to the grids  102 , and an insulation layer  504 . In this example, the electron beam generator  10  forms an electron gun array by including a plurality of electron guns  104  on the insulator  106  at a constant interval. 
     It is preferable that the electron beam generator  10  includes a base power source (not shown), having an output voltage of about 50 kV, for example, that is commonly provided to the cathodes  12 . The cathodes  12  are electrically connected to the base power source via the cathode wiring  500 . The cathode wiring  500  is preferably formed of refractory metal, such as tungsten. In an alternative example, the electron beam generator  10  may include a base power source provided for each of the cathodes  12 . In this case, the cathode wiring  500  is formed so as to electrically connect each cathode  12  to a corresponding base power source. 
     In this example, the electron beam generator  10  includes an individual power source (not shown) having an output voltage of about 200 V, for example, for each of the grid units, each including a plurality of grids  102 . Each grid  102  is connected to the corresponding individual power source via the grid wiring  502 . It is preferable that the grid wiring  502  is formed of refractory metal, such as tungsten. It is also desirable that the grids  102  and the grid wirings  502  are electrically insulated from the cathodes  12  and the cathode wiring  500  by the insulation layer  504 . In this example, the insulation layer  504  is formed of insulating heat-resistant ceramics, such as aluminum oxide. 
     FIG. 34B is a view of the electron beam generator  10  seen from the wafer  44  (shown in FIG.  33 ). In the present example, the electron beam generator  10  forms an electron gun array by arranging a plurality of electron guns  104  at a predetermined interval on the insulator  106 . It is preferable that the grid wirings  502  are formed on the insulation layer  504  so as to suppress the insulation layer  504  from being charged. More specifically, the grid wiring  502  is preferably formed on a straight line connecting the corresponding grid  102  and the insulation layer  504 . The grid wirings  502  may be arranged so as not to cause a short-circuit between adjacent grid wirings  502 , and preferably are arranged in such a manner that the adjacent grid wirings  502  are as close as possible without causing the short-circuit there-between. 
     In the present example, the electron beam generator  10  heats the cathodes  12  by supplying the currents to the cathodes  12  so as to generate thermoelectrons. A heating member, such as a carbon member, may be provided between the cathode  12  and the cathode wiring  500 . By further applying a negative voltage of 50 kV to the cathode  12 , a potential difference is generated between the cathode  12  and the anode  13  (shown in FIG.  33 ). The generated thermoelectrons are drawn from the electron guns by using the thus generated potential difference, thereby the electron beam is obtained by accelerating the thermoelectrons. 
     Then, the obtained electron beam is stabilized by applying a negative voltage of several hundred volts with respect to the potential of the cathode  12  to the grid  102  so as to adjust the amount of the thermoelectrons radiated toward the anode  13 . It is preferable that the electron beam generator  10  adjusts the electron beam amount for each of the electron beams by applying the voltages to the grids  102  independently of each other by means of the individual power sources so as to adjust the amount of the thermoelectrons radiated towards the anode  13 . In an alternative example, the slit cover  11  (shown in FIG. 33) may be used as the anode. 
     Alternatively, the electron beam generator  10  may include a field emission device to generate the electron beams. Moreover, it is preferable that the electron beam generator  10  always generates the electron beams for a period of the exposure process, since it takes a predetermined time for the electron beam generator  10  to generate the electron beams that are stabilized. 
     FIGS. 35A and 35B show an exemplary arrangement of the blanking electrode array  26  shown in FIG.  33 . FIG. 35A is an entire view of the blanking electrode array  26 . The blanking electrode array  26  includes an aperture part  160  having a plurality of apertures through which the electron beams pass, and deflecting electrode pads  162  and grounded electrode pads  164  both of which are used as connectors with the blanking electrode array controller  86  shown in FIG.  33 . It is desirable that the aperture part  160  is arranged at the center of the blanking electrode array  26 . To the deflecting electrode pads  162  and the grounded electrode pads  164 , electric signals are supplied from the blanking electrode array controller  86  via a probe card or a pogo pin array. 
     FIG. 35B is a top view of the aperture part  160 . In FIG. 35B, the horizontal direction of the aperture part  160  is represented with an x-axis while the vertical direction thereof is represented with a y-axis. The x-axis corresponds to a direction in which the wafer stage  46  (shown in FIG. 33) moves the wafer  44  in a graded manner during the exposure process, while the y-axis corresponds to a direction in which the wafer stage  46  moves the wafer  44  continuously. More specifically, with respect to the wafer stage  46 , the y-axis corresponds to a direction in which the wafer  44  is scanned to be exposed while the x-axis corresponds to a direction in which the wafer  44  is moved in a graded manner for exposing an area of the wafer  44  that has not been exposed after the scanning exposure has been completed. 
     The aperture part  160  includes the apertures  166 . The apertures  166  are arranged so as to allow all scanned areas to be exposed. In the example shown in FIG. 35B, the apertures are formed so as to cover the entire area between the apertures  166   a  and  166   b  positioned at both ends of the x-axis. The apertures  166  adjacent to each other in the x-axis direction are preferably arranged at a constant interval. In this case, referring to FIG. 33, it is preferable to determine the interval between the adjacent apertures  166  to be equal to or less than the maximum deflection amount by which the main deflecting unit  42  deflects the electron beam. 
     FIGS. 36A and 36B shows an exemplary arrangement of the first shaping-deflecting unit  18 . FIG. 36A is an entire view of the first shaping-deflecting unit  18 . Please note that the second shaping-deflecting unit  20  and the sub-deflecting unit  38  have the same structure as that of the first shaping-deflecting unit  18 . Thus, in the following description, the structure of the deflecting unit is described based on the structure of the first shaping-deflecting unit  18  as a typical example. 
     The first shaping-deflecting unit  18  includes a substrate  186 , a deflector array  180  and deflecting electrode pads  182  provided on the substrate  186 . The deflector array  180  is provided at the center of the substrate  186 , while the deflecting electrode pads  182  are provided in the peripheral region of the substrate  186 . The deflector array  180  includes a plurality of deflectors each formed by a plurality of deflecting electrodes and an opening. The deflecting electrode pads  182  are electrically connected to the shaping-deflector controller  84  by being connected to a probe card, for example. 
     FIG. 36B shows the deflector array  180 . The deflector array  180  includes the deflectors  184  for deflecting the electron beams, respectively. In FIG. 36B, the horizontal direction of the deflector array  180  is represented with an x-axis. The vertical direction thereof is represented with a y-axis. The x-axis corresponds to a direction in which the wafer stage  46  moves the wafer  44  in a graded manner during the exposure process, while the y-axis corresponds to a direction in which the wafer stage  46  moves the wafer  44  continuously during the exposure process. More specifically, with respect to the wafer stage  46 , the y-axis is a direction in which the wafer  44  is scanned to be exposed, while the x-axis is a direction in which the wafer  44  is moved in a graded manner after the scanning exposure has been completed, in order to expose an area of the wafer  44  that has not been exposed. 
     It is preferable that the deflectors  184  adjacent to each other in the x-axis direction are arranged at a constant interval. In this case, referring to FIG. 33, it is preferable to determine the interval between the deflectors  184  to be equal to or less than the maximum deflection amount by which the main deflecting unit  42  deflects the electron beam. With reference to FIG. 35B, the deflectors  184  of the deflector array  180  are provided to correspond to the apertures of the blanking electrode array  26 , respectively. 
     In conventional techniques, the coaxial lens has been used in order to reduce the beam size. The size-reducing coaxial lens reduces the diameter of the electron beam incident thereon and also converges a plurality of electron beams so as to reduce the interval between the electron beams. Thus, in accordance with the conventional techniques, especially, the interval between the adjacent electron beams reaching the sub-deflecting unit  38  is very small, and therefore it is hard to form the deflector  184  for each of the electron beams. 
     According to the present invention, the multi-axis electron lens is used. Thus, after the electron beams have passed through the multi-axis electron lens for reducing the electron beams, the interval between the adjacent electron beams is not reduced although the diameter of each of the electron beams is reduced. That is, the interval between the adjacent electron beams is sufficient even after the electron beams are reduced, it is possible to easily arrange the deflectors  184  having deflection abilities that can deflect the electron beams by desired amounts at positions in the deflector array  180  that provide a satisfactory deflection efficiency. 
     FIG. 37 is a drawing for explaining the exposure operation for the wafer  44  on the electron beam exposure apparatus  100  according to the present embodiment. First, the operation of the wafer stage  46  during the exposure process is described. In FIG. 37, the horizontal direction of the wafer  44  is represented with an x-axis while the vertical direction thereof is represented with a y-axis. An exposure width Al is a width that can be exposed without moving the wafer stage  46  in the x-axis direction, and corresponds to an interval of the apertures  166  of the blanking electrode array  26  that are adjacent to each other in the x-axis direction, referring to FIG.  35 . With reference to FIG. 33, the shaping-deflector controller  84  controls the shape of the electron beam to be incident, while the blanking electrode array controller  86  controls whether or not the electron beam is to be incident onto the wafer  44 . Then, the wafer-stage controller  92  moves the wafer stage  46  in the y-axis direction, while the main deflector controller  94  and the sub-deflector controller  92  control the positions of the wafer  44  to be illuminated with the electron beams, thereby a first exposure area  400  having the exposure width Al can be exposed. After the first exposure area  400  has been exposed, the wafer stage  46  is moved in the x-direction by the amount corresponding to the exposure width A 1  and then starts to be moved in a direction opposite to the direction in which the wafer stage  46  is moved for exposing the first exposure area  400 , so that a second exposure area  402  can be exposed. By repeating the above-mentioned exposure operation for the entire surface of the wafer  44 , a desired exposure pattern can be exposed onto the entire surface of the wafer  44 . In the example shown in FIG. 37, a single scan performs the exposure from one end to another end of the wafer  44 . Alternatively, only a part of the surface of the wafer  44  may be exposed by the single scan. 
     FIGS. 38A and 38B schematically show deflection operations of the main deflecting unit  42  and the sub-deflecting unit  38  in the exposure process. FIG. 38A shows a main deflection area  410  of the wafer  44  is to be exposed mainly by the deflection operation of the main deflecting unit  42 . One side A 2  of the main deflection area  410  corresponds to the amount by which the main deflecting unit  42  deflects the electron beam during the exposure process. It is preferable that the main deflection areas  410  adjacent to each other in the x-direction are arranged to be in contact with each other. However, the main deflection areas  410  may be arranged in such a manner that at least one of the main deflection areas  410  overlaps the other main deflection area  410  in the x-direction. 
     FIG. 38B schematically shows an exposing operation for exposing the deflection area  410  by the electron beams. One side A 3  of a sub-deflection area  412  of the wafer  44  which is exposed by the deflection operation of the sub-deflecting unit  38  corresponds to the amount by which the sub-deflecting unit  38  can deflect the electron beams during the exposure process. In the present example, the main deflection area  410  is eight times as large as the sub-deflection area  412 . 
     The sub-deflection area  412   a  is exposed by the deflection operation of the sub-deflecting unit  38  to have a desired exposure pattern. After the exposure for the sub-deflecting area  412  has been completed, the main deflecting unit  42  moves the electron beams to the sub-deflection area  412   b . The sub-deflection area  412   b  is then exposed by the deflection operation of the sub-deflecting unit  38  to have a desired exposure pattern. Similarly, the deflection operations of the main deflecting unit  42  and the sub-deflecting unit  38  are repeated along an arrow in FIG. 38B so as to expose desired exposure patterns, thereby the exposure for the main deflection area  410  is completed. 
     FIG. 39 shows an example of the first multi-axis electron lens  16 . Please note that the second, third and fourth multi-axis electron lenses  24 ,  34  and  36  have the same structure as that of the first multi-axis electron lens  16 . Therefore, the structure of the multi-axis electron lens is described based on the first multi-axis electron lens  16  as a typical example in the following description. 
     The first multi-axis electron lens  16  includes a coil part  200  for generating a magnetic field and a lens part  202 . The lens part  202  includes lens openings  204  allowing the electron beams to pass there-through, respectively, and a lens region  206  where the lens openings  204  are provided. The y-axis of the lens region  206  corresponds to the scanning direction of the wafer stage  46  (shown in FIG.  33 ), while the x-axis thereof corresponds to the direction in which the wafer stage  46  is moved in a graded manner. 
     The lens openings  204  are arranged in such a manner that x-coordinates of centers of the respective lens openings  204  have a constant interval, and preferably have an interval corresponding to the amount by which the main deflecting unit  42  deflects the electron beam when the wafer  44  is exposed by the electron beam, referring to FIG.  33 . More specifically, it is preferable that the lens openings  204  are arranged to correspond to the apertures  166  of the blanking electrode array  26  and the positions of the deflectors  184  included in the deflector array  180 , respectively, referring to FIGS. 35A to  36 B. Moreover, the lens part  202  preferably includes at least one dummy opening  205  described with reference to FIGS. 8-11. 
     FIGS. 40A and 40B show examples of the cross section of the first multi-axis electron lens  16 . As shown in FIG. 40A, the lens part  202  may include non-magnetic conductive members  208  to interpose lens magnetic conductive members  210 . Moreover, the lens magnetic conductive members  210  may be made thicker, as shown in FIG.  40 B. In this case, coulomb force generated between the adjacent electron beams can be blocked more strongly. In this example, the lens magnetic conductive member  210  maybe made thicker in such a manner that the surfaces of the lens part  202  are positioned on substantially the same place as that the surfaces of the coil part  200 , as shown in FIG.  40 B. Alternatively, the lens magnetic conductive member  210  may be formed to be thicker so that the lens part  202  is thicker than the coil part  200 . 
     FIG. 41 shows an electron beam exposure apparatus  100  according to another embodiment of the present invention. The electron beam apparatus  100  includes a blanking aperture array (BAA) device  27  in place of the blanking electrode array  26  included in the electron beam exposure apparatus shown in FIG.  1 . Moreover, the electron beam exposure apparatus  100  of the present embodiment includes electron lenses and deflecting units having the same functions and operations as those of the electron lenses and deflecting units provided in the electron beam exposure apparatus shown in FIG. 33, thereby illuminating the wafer with the electron beams divided by the BAA device  27  (that are divided by shaping members). The components labeled with the same reference numerals in the electron beam exposure apparatus shown in FIG. 41 may have the same structures and functions as those shown in FIG.  1  and/or FIG.  33 . In the following description, the structures, operations and functions that are different from those of the electron beam exposure apparatuses shown in FIGS. 1 and 33 are described. 
     The electron beam exposure apparatus  100  includes the exposure unit  150  for performing a predetermined exposure process using electron beams for a wafer  44 , and a controlling system  140  for controlling operations of the respective components included in the exposure unit  150 . 
     The exposure unit  150  includes: a body  80  provided with a plurality of exhaust holes  70 ; an electron beam shaping unit which can emit a plurality of electron beams and shape a cross-sectional shape of each electron beam into a desired shape; an illumination switching unit which can switch for each electron beam independently whether or not the electron beam is cast onto the wafer  44 ; and an electron optical system including a wafer projection system which can adjust the orientation and size of a pattern image transferred onto the wafer  44 . In addition, the exposure unit  150  includes a stage system having a wafer stage  46  on which the wafer  44  onto which the pattern is to be transferred by exposure can be placed and a wafer-stage driving unit  48  which can drive the wafer stage  46 . 
     The electron beam shaping unit includes an electron beam generator  10  which can generate a plurality of electron beams, an anode  13  which allows the generated electron beams to be radiated, a slit deflecting unit  15  for deflecting the electron beams after passing through the anode  13  independently of each other, a first multi-axis electron lens  16  which can converge the electron beams to adjust focal points of the electron beams independently of each other, a first lens-intensity adjuster  17  which can adjust the lens intensity of the first multi-axis electron lens  16  for each of the electron beams independently of the other electron beams, and the BAA device  27  for dividing the electron beams that have passed through the first multi-axis electron lens  16 . 
     The illumination switching unit includes the BAA device  27  that switches for each of the electron beams whether or not the electron beam is to be incident on the wafer  44 , and an electron beam blocking member  28  that has a plurality of openings allowing the electron beams to pass there-through and can block the electron beams deflected by the BAA device  27 . In this example, the BAA device  27  serves as a component of the electron beam shaping unit for shaping the cross-sectional shapes of the electron beams incident thereon and a component of the illumination switching unit. The openings included in the electron beam blocking member  28  may have cross-sectional shapes each of which becomes wider along the illumination direction of the electron beams in order to allow the electron beams to efficiently pass. 
     The wafer projection system includes: a third multi-axis electron lens  34  which can adjust the rotations of the electron beams to be incident onto the wafer  44 ; a fourth multi-axis electron lens  36  which can converge a plurality of electron beams independently of each other and adjust the reduction ratio of each electron beam to be incident onto the wafer  44 ; a deflecting unit  60  which can deflect a plurality of electron beams independently of each other to direct desired portions on the wafer  44 ; and a coaxial lens  52  which has a first coil  40  and a second coil  54  and can serve as an objective lens for the wafer  44  by converging a plurality of electron beams independently of each other. In this example, it is preferable that the coaxial lens  52  is arranged to be closer to the wafer  44  than the multi-axis electron lens. Moreover, although the third multi-axis electron lens  34  and the fourth multi-axis electron lens  36  are integrated with each other in this example, they may be formed as separate components in an alternative example. 
     The controlling system  140  includes a general controller  130 , a multi-axis electron lens controller  82 , a coaxial lens controller  90 , a backscattered electron processing unit  99 , a wafer-stage controller  96  and an individual controller  120  which can control exposure parameters for each of the electron beams. The general controller  130  is, for example, a work station and can control the respective controllers included in the individual controller  120 . The multi-axis electron lens controller  82  controls currents to be respectively supplied to the first, third and fourth multi-axis electron lenses  16 ,  34  and  36 . The coaxial electron lens controller  90  controls the amounts of currents to be supplied to the first and second coils  40  and  54  of the coaxial lens  52 . The backscattered electron processing unit  99  receives a signal based on the amount of backscattered electrons or secondary electrons detected in a backscattered electron detector  50  and notify the general controller  130  that the backscattered electron processing unit  99  received the signal. The wafer-stage controller  96  controls the wafer-stage driving unit  48  so as to move the wafer stage  46  to a predetermined position. 
     The individual controller  120  includes an electron beam controller  80  for controlling the electron beam generator  10 , a lens-intensity controller  88  for controlling the lens-intensity adjuster  17 , a BAA device controller  87  for controlling voltages to be applied to deflection electrodes included in the BAA device  27  and a deflector controller  98  for controlling voltages to be applied to electrodes included in the deflectors of the deflecting unit  60 . 
     Next, the operation of the electron beam exposure apparatus  100  in the present embodiment is described. First, the electron beam generator  10  generates a plurality of electron beams. The generated electron beams pass through the anode  13  to enter the slit deflecting unit  15 . The slit deflecting unit  15  adjusts the incident positions on the BAA device  27  onto which the electron beams after passing through the anode  13  are incident. 
     The first multi-axis electron lens  16  converges the electron beams after passing through the slit deflecting unit  15  independently of each other, thereby the focus adjustment of the electron beam with respect to the BAA device  27  can be performed for each electron beam. The first lens-intensity adjuster  17  adjusts the lens intensity in each lens opening of the first multi-axis electron lens  16  in order to correct the focus position of the corresponding electron beam incident on the lens opening. The electron beams after passing through the first multi-axis electron lens  16  is incident on a plurality of aperture parts provided in the BAA device  27 . 
     The BAA device controller  87  controls whether or not voltages are applied to deflection electrodes provided in the vicinity of the respective apertures of the BAA device  27 . Based on the voltages applied to the deflection electrodes, the BAA device  27  switches for each of the electron beams whether or not the electron beam is to be incident on the wafer  44 . When the voltage is applied, the electron beam passing through the corresponding aperture is deflected. Thus, the deflected electron beam cannot pass through a corresponding opening of the electron beam blocking member  28 , so that it cannot be incident on the wafer  44 . When the voltage is not applied, the electron beam passing through the corresponding aperture is shaped in the BAA device  27  without being deflected, so that it can pass through the corresponding opening of the electron beam blocking member  28 . Thus, the electron beam can be incident on the wafer  44 . 
     The electron beam that has not been deflected by the BAA device  27  passes through the electron beam blocking member  28  to be incident on the third multi-axis electron lens  34 . The third multi-axis electron lens  34  then adjusts the rotation of the electron beam image to be incident on the wafer  44 . Moreover, the fourth multi-axis electron lens  36  reduces the illumination diameter of the electron beam incident thereon. 
     The deflector controller  98  controls a plurality of deflectors included in the deflecting unit  60  independently of each other. The deflecting unit  60  deflects the electron beams incident on the deflectors independently of each other, in such a manner that the deflected electron beams are incident on the desired positions on the wafer  44 . The electron beams after passing through the deflecting unit  60  are subjected to the focus adjustment with respect to the wafer  44  by the coaxial lens  52  having the first and second coils  40  and  54 , respectively, so as to be made incident on the wafer  44 . 
     During the exposure process, the wafer-stage controller  96  moves the wafer stage  48  in predetermined directions. The BAA device controller  87  determines the apertures that allow the electron beams to pass there-through and performs an electric-power control for the respective apertures. In accordance with the movement of the wafer  44 , the apertures allowing the electron beams to pass there-through are changed and the electron beams after passing through the apertures are deflected by the deflecting unit  60 . In this way, the wafer  44  is exposed to have a desired circuit pattern transferred. 
     The electron beam exposure apparatus  100  of the present embodiment converges a plurality of electron beams independently of each other. Thus, although a cross over is formed for each electron beam, all the electron beams as a whole do not have a cross over. Therefore, even in a case where the current density of each electron beam is increased, the electron beam error that may cause a shift of the focus or position of the electron beam due to coulomb interaction can be greatly reduced. 
     FIGS. 42A and 42B show an exemplary arrangement of the BAA device  27 . As shown in FIG. 42A, the BAA device  27  includes a plurality of aperture parts  160  each having a plurality of apertures  166  allowing the electron beams to pass, and deflecting electrode pads  162  and grounded electrode pads  164  both of which are used as connectors with the BAA controller  87  shown in FIG.  41 . It is desirable that each of the aperture parts  160  and the corresponding lens opening of the first multi-axis electron lens  16  are arranged coaxially. Also, it is preferable that the BAA device  27  includes at least one dummy opening  205  (see FIG. 41) through which no electron beam passes provided in the surrounding area of the aperture parts  160 . In this case, the inductance of the exhaustion in the body  8  can be reduced, allowing the efficient reduction of the pressure in the body  8 . 
     FIG. 42B is atop view of the aperture part  160 . As described above, the aperture part  160  includes a plurality of apertures  166 . It is preferable that the aperture  166  has a rectangular shape. The electron beam incident on each aperture part  160  is divided and shaped so that the divided electron beams have cross-sectional shapes in accordance with the shapes of apertures  166 . As described above, since the electron beam exposure apparatus  100  of the present embodiment includes the BAA device  27 , the electron beam exposure apparatus  100  can divide each of the electron beams generated by the electron beam generator  10  into a plurality of beams so that the wafer  44  is exposed by the divided electron beams. Thus, it is possible to make a number of electron beams incident on the wafer  44 , thereby it takes an extremely short time to expose the pattern onto the wafer  44 . 
     FIG. 43A is a top view of the third multi-axis electron lens  34 . Please note that the fourth multi-axis electron lens  36  may have the same structure as that of the third multi-axis electron lens  34 . Therefore, in the following description, the structure of the third multi-axis electron lens  34  is described as a typical example. 
     As shown in FIG. 43A, the third multi-axis electron lens  34  includes a coil part  200  for generating a magnetic field and a lens part  202 . The lens part  202  has a plurality of lens regions  206  in each of which a plurality of lens openings through which the electron beams pass are provided. It is desirable to coaxially arrange the lens region  206  of the lens part  202 , the corresponding lens opening of the first multi-axis electron lens  16  and the corresponding aperture part  160  of the BAA device  27 . 
     FIG. 43B shows each lens region  206 . The lens region  206  has a plurality of lens openings  204 . It is desirable to arrange each lens opening  204 , a corresponding one of the apertures  166  provided in the aperture part  160  of the BAA device  27 , and a corresponding one of the deflectors  184  included in the deflector array  180  coaxially. Moreover, the lens part  202  preferably includes at least one dummy opening  205  described referring to FIG. 8-11. In this case, it is preferable that the dummy opening  205  is provided on the outer side of the region where a plurality of lens regions  206  are provided. 
     FIG. 44A is a top view of the deflecting unit  60 . The deflecting unit  60  includes a substrate  186 , a plurality of deflector arrays  180  and a plurality of deflecting electrode pads  182 . The deflector arrays  180  are desirably arranged at the center of the substrate  186 , while the deflecting electrode pads  182  are provided in the peripheral region of the substrate  186 . It is also desirable that each of the deflector arrays  180 , the corresponding aperture part  160  of the BAA device  27 , and the corresponding lens regions  206  of the third and fourth multi-axis electron lenses  34  and  36  are arranged coaxially. Moreover, the deflecting electrode pads  182  are electrically connected to the deflector controller  98  (shown in FIG. 41) via a connector such as a probe card or a pogo pin array. 
     FIG. 44B shows an example of the deflector array  180 . The deflector array  180  has a plurality of deflectors  184  each formed by a plurality of deflecting electrodes and an opening. It is desirable to arrange the deflector  184  coaxially with a corresponding one of the apertures  166  in the aperture part  160  of the BAA device  27 , and corresponding ones of the lens openings  204  provided in the lens regions  206  of the third and fourth multi-axis electron lenses  34  and  36 . 
     FIGS. 45A through 45G illustrate a fabrication process of the lens part  202  included in the multi-axis electron lens according to an embodiment of the present invention. First, a conductive substrate  300  is prepared. As shown in FIG. 45A, a photosensitive layer  302  is applied onto the conductive substrate  300 . The photosensitive layer  302  is preferably formed by spin-coating or making a thick resist film having a predetermined thickness adhere to the substrate  300 , for example. The photosensitive layer  302  is formed to have a thickness equal to or thicker than the thickness of the lens part  202 . 
     FIG. 45B shows an exposure process in which a predetermined pattern is formed by exposure and the first removal process in which a predetermined area is removed. The predetermined pattern is formed based on the diameter of the lens part  202  and the pattern of the lens openings  204  through which a plurality of electron beams pass, referring to FIGS. 8-11,  39 ,  43 A and  43 B. More specifically, the predetermined pattern is determined by the diameter of the lens part  202  and the diameter and position of the lens opening  204 . Then, a lens-forming mold  304  and a lens-opening-forming mold  306  to be used for forming the lens part  202  and the lens opening  204  in an electro forming process described later are formed based on the diameter of the lens part  202  and the diameter and position of the lens opening  204 , respectively, by the exposure process and the first removal process. 
     The predetermined pattern may be further formed based on a pattern of the dummy opening through which no electron beam passes. In this case, a dummy-opening-forming mold to be used for forming the dummy opening may be formed by the exposure process and the first removal process. The dummy-opening-forming mold may be formed to have a different diameter from that of the lens-opening forming mold. 
     In the exposure process, it is preferable to use an exposure method corresponding to an aspect ratio that is a ratio of the opening diameter to the opening depth of the lens opening  204 . The opening diameter of the lens opening  204  is preferably in the range of 0.1 mm to 2 mm, while the opening depth is preferably in the range of 5 mm to 50 mm. In this example, the lens opening has an opening diameter of about 0.5 mm and an opening depth of about 20 mm, that is, the aspect ratio is about 40. Therefore, it is preferable to use an X-ray exposure method that has a high transmissivity for the photosensitive layer and therefore can easily form a high aspect-ratio pattern. In this case, the photosensitive layer  302  is preferably a positive or negative type photoresist for X-ray exposure, and is exposed with an X-ray exposure mask having a pattern corresponding to the patterns of the lens-forming mold  304  and the lens-opening-forming mold  306 . Then, an exposed area in a case of the positive type photosensitive layer  302  or an area that is not exposed in a case of the negative type photosensitive layer  302  is removed, thereby forming the lens-forming mold  304  and the lens-opening-forming mold  306  are obtained. 
     In a process shown in FIG. 45C, the first magnetic conductive member  210   a  is formed by electro forming. The first magnetic conductive member  210   a  is formed of, for example, nickel alloy to have a thickness of about 5 mm by electroplating using the conductive substrate  300  as an electrode. 
     In a process shown in FIG. 45D, the non-magnetic conductive member  242  is formed by electro forming. The non-magnetic conductive member  242  is formed of, for example, copper to have a thickness of about 5-20 mm by electroplating using the first magnetic conductive member  210   a  as an electrode. 
     The second magnetic conductive member  210   b  is then formed by electro forming in a process shown in FIG.  45 E. The second magnetic conductive member  210   b  is formed of, for example, nickel alloy to have a thickness of about 5-20 mm by electroplating using the non-magnetic conductive member  242  as an electrode. 
     The photosensitive layer  302  is then removed in the second removal process shown in FIG.  45 F. In the second removal process, the remaining parts of the photosensitive layer  302 , that is, the lens-forming mold  304  and the lens-opening-forming mold  306  are removed. As a result, the lens openings  204  that have a plurality of first openings included in the first magnetic conductive member  210   a , a plurality of through holes included in the non-magnetic conductive member that are arranged coaxially with the first openings, and a plurality of second openings included in the second magnetic conductive member  210   b  that are arranged coaxially with the first openings and the through holes are formed, respectively. 
     FIG. 45G illustrates a peeling process in which the conductive substrate  300  is peeled off. By peeling the conductive substrate  300  off, the lens part  202  is obtained. The conductive substrate  300  may be removed by using a drug solution that can remove the conductive substrate  300  with substantially no reaction with the first and second magnetic conductive members  210   a  and  210   b  and the non-magnetic conductive member  242 . 
     FIGS. 46A through 46E illustrate processes for forming the projections  218 . FIG. 46A shows the first lens magnetic conductive member  210   a  formed on the conductive substrate  300  in the process shown in FIG.  45 C. On the first lens magnetic conductive member  210   a , the lens-opening-forming molds  306  are formed so as to correspond to positions at which the projections  218  described with reference to FIG. 14B are to be formed. Then, as shown in FIG. 46C, first projections  218   a , the non-magnetic member  242  and second projections  218   b  are formed by a similar process to that described in FIGS. 45C through 45E. 
     The lens-opening-forming molds  306  are then removed and thereafter opening areas where the lens-opening-forming molds  306  are removed are filled with a filling member  314 . It is desirable to form the filling member  34  from material that can be removed selectively with respect to materials for the magnetic conductive members  210 , the projections  218  and the non-magnetic conductive member  242 . It is also desirable that the filling member  314  is formed to have such a thickness that the levels of the filling member  314  and the second projections  218  are substantially the same. After the formation of the filling member  314 , the lens-opening-forming molds  306  are formed again in a similar manner to the processes described before, thereby forming the second magnetic conductive member  210   b . Then, the lens-opening-forming molds  306 , the filling member  314  and the conductive substrate  300  are removed, as shown in FIG. 46E, so that the lens part  202  is obtained. 
     The first and second projections  218   a  and  218   b  may be formed from material having a different magnetic permeability from the material for the lens magnetic conductive members  210 . Moreover, the cut portions may be formed by forming lens-opening-forming molds having a pattern obtained by reversing the lens-opening-forming molds  306  as shown in FIG. 46B, and then etching the lens magnetic conductive members  210  by using the lens-opening-forming molds as a mask. 
     FIGS. 47A and 47B illustrate another example of the fabrication method of the lens part  202 . After the formation of the second magnetic conductive member has been completed, the formation of the first magnetic conductive member, the formation of the non-magnetic conductive member, and the formation of the second magnetic conductive member are performed a plurality of times repeatedly. Then, by performing the second removal process and the peeling process, a lens block  320  including a plurality of lens parts  202  is obtained, as shown in FIG.  47 A. The individual lens parts  202  may be obtained by slicing the lens block  320 , as shown in FIG.  47 A. Alternatively, the lens parts  202  may be obtained by forming the lens block  320  so as to include separation members  322  between the lens parts  202  and then removing only the separation members  322  by using a drug solution that can remove the separation members  322  with substantially no reaction with the non-magnetic conductive member  242  and the second magnetic conductive member  210   b . In these examples, the photosensitive layer  302  is desirably formed to have a thickness thicker than the thickness of the lens block  320 . 
     FIGS. 48A through 48C illustrate a fixing process for fixing the coil part  200  and the lens part  202 . FIG. 48A shows the coil part  200  for generating the magnetic field. It is preferable that the coil part  200  has an inner diameter corresponding to the diameter of the lens part  202  so as to have an annular shape. The coil part  200  has the coil magnetic conductive member  212  provided in the surrounding area of the coil  214  that can generate the magnetic field and a space  310 . The space  310  may include a non-magnetic conductive member or be filled with the non-magnetic conductive member. It is preferable that the coil magnetic conductive member  212  and the coil  214  are formed by fine machining, for example. The coil part  200  is formed by joining the magnetic conductive member  212  and the coil  214  by fine machining, such as screwing, welding or bonding. The coil magnetic conductive member  212  is preferably formed from material having a different magnetic permeability from that of the material for the lens magnetic conductive member  210 . 
     FIG. 48B shows a process for forming a support  312  used for fixing the lens part  202  to the coil part  200 . After the coil part  200  has been formed, the support  312  formed of non-magnetic conductive material is joined to the coil part  200  by fine machining, such as screwing, welding or bonding. It is desirable to arrange the support  312  at such a position that the support  312  supports the lens part  202  so as to fit the space  310  of the coil part  200  to the non-magnetic conductive member  242  of the lens part  202  in the fixing process described later. The support  312  may be a single annular member or include a plurality of convex members that supports the lens part  202  as a plurality of supporting points. Moreover, the support  312  may be formed integrally with the magnetic conductive member  212 . More specifically, the magnetic conductive member  312  may be formed to include a convex portion serving as the support  312 . In this case, it is desirable that the support  312  is formed to have such a dimension that the support  312  has no effect on the magnetic field generated in the lens opening  204  by the first and second lens magnetic conductive members  210   a  and  210   b.    
     FIG. 48C shows the fixing process for fixing the coil part  200  and the lens part  202  by means of the support  312 . The lens part  202  is preferably joined to be fixed to the coil part  200  by bonding or fitting the space  310  of the coil part  200  to the non-magnetic conductive member  242  or meshing the space  310  with the non-magnetic conductive member  242 . The support  312  may be removed after the lens part  202  is fixed to the coil part  200 . 
     FIG. 49 is a flowchart of a fabrication process of a semiconductor device according to an embodiment of the present invention, in which the semiconductor device is fabricated from a wafer. In Step S 10 , the fabrication process starts. First, photoresist is applied onto an upper surface of the wafer  44  in Step S 12 . The wafer  44  on which the photoresist is applied is then placed on the wafer stage  46  in the electron beam exposure apparatus  100 , referring to FIGS. 1 and 17. The wafer  44  is exposed to have a pattern image transferred thereon by being illuminated with the electron beams by the focus adjustment process in which the focus adjustment of the electron beam is performed for each of the electron beams independently of other electron beams by means of the first, second, third, and fourth multi-axis electron lenses  16 ,  24 ,  34  and  36 , and the illumination switching process in which it is switched by the blanking electrode array  26  for each electron beam independently of other electron beams whether or not the electron beam is to be incident on the wafer  44 , as described before referring to FIGS. 1,  33  and  41 . 
     The wafer  44  exposed in Step S 14  is then immersed into developing solution to be developed, and thereafter unnecessary resist is removed (Step S 16 ). In Step S 18 , a silicon substrate, an insulating layer or a conductive layer in areas of the wafer where the photoresist is removed are etched by anisotropic etching using plasma. In Step S 20 , impurities such as boron or arsenic ions are doped into the wafer in order to fabricate a semiconductor device such as a transistor or a diode. In Step S 22 , the impurities are activated by annealing. In Step S 24 , the wafer  44  is cleaned by a cleaning solution to remove organic contaminant or metal contaminant on the wafer. Then, a conductive layer and an insulating layer are deposited to form a wiring layer and an insulator between the wirings. By appropriately combining the processes in Steps S 12  to S 26  and repeating the combined processes, it is possible to fabricate the semiconductor device having an isolation region, a device region and wirings on the wafer. In Step S 28 , the wafer on which a desired circuit has been formed is cut, and then assembly of chips is performed. In Step S 30 , the fabrication flow of the semiconductor device is finished. 
     As is apparent from the above description, according to the present invention, a plurality of electron beams can be converged independently of each other and can be controlled for each of the electron beams whether or not to be incident on the wafer, by including the multi-axis electron lens and the illumination switching unit. Thus, since the electron beams can be controlled independently without cross over, it is possible to greatly improve throughput. 
     Although the present invention has been described by way of exemplary embodiments, it should be understood that those skilled in the art might make many changes and substitutions without departing from the spirit and the scope of the present invention which is defined only by the appended claims.