Abstract:
In order to design a lithography exposure device comprising a mounting device for the layer sensitive to light, an exposure unit comprising several laser radiation sources and an optical focusing means associated with the laser radiation sources, a movement unit for generating a relative movement between the optical focusing means and the mounting device and a control for controlling intensity and position of the exposure spots in such a manner that exposed structures which are as precisely structured as possible can be produced, it is suggested that the optical focusing means have an end lens which generates focal points of the laser radiation exiting from each of the laser radiation sources close to the light-sensitive layer, that a laser radiation field propagate in the direction of the light-sensitive layer for generating each of the exposure spots from the respective focal points and have a power density which leads in the conversion area in the light-sensitive layer to the formation of a channel which penetrates the light-sensitive layer with an index of refraction increased in relation to its surroundings due to the Kerr effect and guides the respective laser radiation field in a spatially limited manner.

Description:
[0001]     This application is a continuation of International application No. PCT/EP2004/010371 filed on Sep. 16, 2004.  
         [0002]     The present disclosure relates to the subject matter disclosed in International application No. PCT/EP2004/010371 of Sep. 16, 2004 and German application No. 103 46 201.5 of Sep. 29, 2003, which are incorporated herein by reference in their entirety and for all purposes. 
     
    
     BACKGROUND OF THE INVENTION  
       [0003]     The invention relates to a lithography exposure device for producing exposed structures extending in a surface area in a layer sensitive to light, comprising a mounting device for the light-sensitive layer, an exposure unit comprising several laser radiation sources, an optical focusing means associated with the laser radiation sources for the laser radiation exiting from the respective laser radiation sources, the optical focusing means generating from the laser radiation of each of the laser radiation sources an exposure spot effective in the light-sensitive layer with a predetermined extension transverse to a direction of exposure movement, a movement unit for generating a relative movement between the optical focusing means and the mounting device in the direction of exposure movement and a control for controlling intensity and position of the exposure spots relative to the light-sensitive layer in such a manner that a plurality of conversion areas penetrating the light-sensitive area can be generated by means of the exposure spots, the material of the light-sensitive layer being converted in these conversion areas from an initial state into an exposed state and the conversion areas together resulting in the exposed structure.  
         [0004]     A lithography exposure device of this type is known from EP 1 319 984.  
         [0005]     The object of lithography exposure devices is, however, always to configure the extension of the exposure spot as precisely as possible in order to be able to produce exposed structures which are structured as precisely as possible.  
       SUMMARY OF THE INVENTION  
       [0006]     This object is accomplished in accordance with the invention, in a lithography exposure device of the type described at the outset, in that the optical focusing means has an end lens which generates focal points of the laser radiation exiting from each of the leaser radiation sources close to the light-sensitive layer, that a laser radiation field propagates in the direction of the light-sensitive layer for generating each of the exposure spots from the respective focal points and has a power density which leads in the conversion area in the light-sensitive layer to the formation of a channel which penetrates the light-sensitive layer with an index of refraction increased in relation to its surroundings by the Kerr effect and guides the respective laser radiation field in a spatially limited manner.  
         [0007]     The advantage of the solution according to the invention is, therefore, to be seen in the fact that as a result of the formation of the channel penetrating the light-sensitive layer in a direction of propagation, this formation being achieved on account of the Kerr effect, the extension of the laser radiation field transversely to the direction of propagation can be reduced, on the one hand, and, in addition, a considerable depth of focus in the exposed structure can be achieved due to the formation of the channel with an increased index of refraction and this leads to the exposed structure having very precise edges in relation to unexposed areas of the light-sensitive layer so that, on account of the high quality of the edges of the exposed areas, it is possible to produce exposed structures which have sharply defined contours and can, therefore, also be more finely structured than the structures which can be generated without such a formation of a channel with an increased index of refraction.  
         [0008]     It is possible, in particular, with the solution according to the invention to obtain extensions of the exposure spots and the converted areas which are in the range of the wavelength or smaller than this.  
         [0009]     A particularly advantageous solution provides for the power density of the laser radiation field in the conversion area of the light-sensitive layer to be in a range of approximately 10 6  to approximately 10 8  W/cm 2 .  
         [0010]     In order to achieve this high power density, the most varied of possibilities are conceivable. For example, it would be conceivable to use laser radiation sources having a very high power density.  
         [0011]     A particularly simple solution provides for the respective laser radiation field to be formed by short pulses with excessive power.  
         [0012]     The short pulses preferably have a pulse duration in the range of a few nanoseconds or are even shorter, preferably in the range of picoseconds or even shorter.  
         [0013]     With respect to the increase in the index of refraction required for the advantageous formation of a channel in the light-sensitive layer, no further details have so far been given. One particularly favorable solution, for example, provides for the Kerr effect to lead in the channel to an increase in the index of refraction in relation to the surroundings in the light-sensitive layer by more than 0.1.  
         [0014]     In the case of one advantageous embodiment, it is possible with the lithography exposure device according to the invention for the channel to have, transversely to the direction of propagation of the laser radiation, a cross sectional surface area which corresponds at the most to the extension of the corresponding focal point in the end surface.  
         [0015]     With respect to the design of the end lens, no further details have been given in conjunction with the preceding explanations concerning the individual embodiments, expect for the fact that this generates the focal points arranged close to the light-sensitive layer from the laser radiation.  
         [0016]     Precisely exposed structures may be produced particularly favorably with an advantageous lithography exposure device when, in addition or alternatively to the features of the lithography exposure device described above, the end lens generates the focal points close to or in its end surface facing the light-sensitive layer. In this case, focal points with a slight, spatial extension may be generated and the laser radiation field propagating from them likewise has a slight, spatial extension.  
         [0017]     Furthermore, alternatively or in addition to the preceding embodiments, it is provided in a further, preferred lithography exposure device for the end surface of the end lens to be flat in an area penetrated by the laser radiation so that the focal points which are generated are likewise located in a plane preferably parallel to the surface of the light-sensitive layer.  
         [0018]     An end lens, which is shaped in a similar manner to a hemisphere or a hyperhemisphere, has proven to be particularly suitable within the scope of the solution according to the invention since focal points which are particularly favorable and limited in a spatially narrow manner may be generated with such shapes of the end lenses.  
         [0019]     With respect to the exact position of the focal points in the end lens, no further details have so far been given. The focal points could, for example, be located in an area bordering directly on the end surface but outside the solid-state body. One particularly favorable embodiment provides for the focal points to be located in the solid-state body of the end lens and in an area of the end lens bordering on its end surface, i.e., to border, in particular, directly on the end surface itself or be located in it.  
         [0020]     In order to be able to utilize the limited extension of the field propagating from the respective focal point in an optimum manner it is provided for the end lens to be arranged with its end surface at a distance from the light-sensitive layer which is smaller than half the length of the light wave of the laser radiation in a vacuum.  
         [0021]     The distance is preferably so slight that it amounts to less than approximately 50 nanometers.  
         [0022]     The light-sensitive layer can, in principle, be any type of light-sensitive layer. One particularly advantageous solution provides for the light-sensitive layer to be a photosensitive coating layer.  
         [0023]     Particularly fine, exposed structures may be generated with the solution according to the invention, in particular, when a diaphragm structure reducing the spatial extension of the exposure spots to dimensions in the range of the wavelength of the laser radiation or to smaller dimensions is associated with the end surface of the optical focusing means facing the light-sensitive layer.  
         [0024]     Such a diaphragm structure is preferably built up such that this limits the laser radiation field in the direction of a component of its electric field.  
         [0025]     Such a diaphragm structure preferably has at least one opening extending in a longitudinal direction over more than one wavelength of the laser radiation.  
         [0026]     The opening preferably extends over a multiple of the wavelength of the laser radiation.  
         [0027]     Furthermore, it is preferably provided for the opening to have longitudinal side edges which have a distance from one another of a wavelength of the laser radiation or less.  
         [0028]     The distance between the longitudinal side edges is preferably, at the most, two thirds of a wavelength, even better at the most half the wavelength.  
         [0029]     The lithography exposure device according to the invention is preferably designed such that with it each exposure spot is movable in a direction of deflection extending transversely to the direction of exposure movement.  
         [0030]     In this case, the diaphragm structure is preferably designed such that at least one of the openings of the diaphragm structure extends in the direction of deflection.  
         [0031]     One particularly advantageous solution provides for the diaphragm structure to have an opening extending at least over an area of movement of the respective exposure spot in the direction of deflection.  
         [0032]     In the simplest case, the electric field is aligned such that the laser radiation field can pass through the opening over the entire length of the opening.  
         [0033]     Another advantageous solution provides for the diaphragm structure to have in the direction of deflection consecutive passage areas for the laser radiation field. This means that the laser radiation field does not have the possibility of passing through the diaphragm structure over the entire area of movement of the exposure spot in the direction of deflection but rather it is necessary for the laser radiation field to pass through the diaphragm structure only at specific, predetermined passage areas.  
         [0034]     Such a solution has the advantage that with it the position of possible exposure spots may be determined solely by positioning the diaphragm structure relative to the light-sensitive layer and there is no necessity to determine the position of the exposure spot to be generated by switching the intensity of the laser radiation field on and off during the course of the movement of the exposure spot in the direction of the direction of deflection.  
         [0035]     Such passage areas may be achieved particularly favorably in that they are formed by intersecting areas of two slit-shaped openings.  
         [0036]     One possibility for realizing such a plurality of intersecting areas is for one of the slit-shaped openings to extend through the passage areas in the direction of deflection.  
         [0037]     In this case, it would still be conceivable to limit the openings in their extension in the direction of deflection.  
         [0038]     One particularly favorable solution provides for the slit-shaped opening extending in the direction of deflection to extend over the entire area of movement of the respective laser radiation field in the direction of deflection.  
         [0039]     An alternative embodiment of a solution according to the invention provides for the openings to extend at an angle to the direction of deflection.  
         [0040]     In this respect, two respective openings are preferably arranged such that they extend at an angle of 90° in relation to one another in order to achieve as high an intensity as possible of the laser radiation field passing through in the region of the passage area.  
         [0041]     With respect to the alignment of the electric field of the laser radiation field of the respective laser radiation, it is preferably provided for the electric field of the respective laser radiation to extend transversely to the longitudinal direction of the respective openings, i.e., at an angle or at right angles thereto.  
         [0042]     If only one opening is present, it is preferably provided for the electric field to extend at right angles to the longitudinal direction of the opening. If several openings are present, for example, those with intersecting areas intended to represent passage areas, it is preferably provided for the electric field to be inclined as far as possible at the same angle in relation to the longitudinal direction of both openings.  
         [0043]     Since the longitudinal directions of two openings are preferably at an angle of approximately 90° in relation to one another in the region of the intersecting areas, it is preferably provided, in this case, for the electric field to be aligned such that it extends at an angle of approximately 45° in relation to the longitudinal direction of each of the openings.  
         [0044]     In conjunction with the preceding explanations concerning a diaphragm structure provided, it has not been explained in detail where the diaphragm structure to be associated with the optical focusing means is to be arranged.  
         [0045]     One advantageous embodiment provides for the diaphragm structure to be arranged directly on an end surface of the end lens.  
         [0046]     Another possibility provides for the diaphragm structure to be arranged on a carrier which abuts, for its part, on the end surface of the end lens.  
         [0047]     In this respect, the carrier is preferably arranged on the end surface of the end lens with a side located opposite the diaphragm structure.  
         [0048]     In order to avoid reflections during the transition between the end lens and the carrier, it is preferably provided for the carrier to be connected to the end surface of the end lens in a manner adapted with respect to the index of refraction.  
         [0049]     Such a connection adapted with respect to the index of refraction may be realized, for example, in that the carrier is connected to the end surface of the end lens free from adhesive.  
         [0050]     One possibility for an adhesive-free connection provides for the carrier to be connected to the end surface of the end lens by way of bonding.  
         [0051]     Another adhesive-free connection provides for the carrier to be connected to the end surface of the end lens by blowing them together.  
         [0052]     Finally, it is, however, also conceivable to connect the carrier to the end lens by means of an adhesive adapted with respect to the index of refraction.  
         [0053]     With respect to the design of the diaphragm structure, no further details have so far been given. The diaphragm structure may be formed by any type of diaphragm material which is suitable for partially suppressing the laser radiation.  
         [0054]     One particularly advantageous solution provides for the diaphragm structure to be formed by a metal layer which may be applied to a surface and structured very easily.  
         [0055]     Additional features and advantages of the invention are the subject matter of the following description as well as the drawings illustrating several embodiments.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0056]      FIG. 1  shows a fundamental, schematic construction of a lithography exposure device according to the invention;  
         [0057]      FIG. 2  shows a schematic illustration of exposed structures which can be produced with the lithography exposure device according to the invention and the image spots used for this purpose;  
         [0058]      FIG. 3  shows a schematic illustration of the construction of a lithography exposure device according to the invention summarized in blocks;  
         [0059]      FIG. 4  shows a schematic illustration of a mode of operation of one embodiment of a deflection unit of a lithography exposure device according to the invention;  
         [0060]      FIG. 5  shows a schematic sectional illustration of a first embodiment of an exposure unit according to the invention;  
         [0061]      FIG. 6  shows a section through an end lens of the first embodiment according to  FIG. 5 ;  
         [0062]      FIG. 7  shows a sectional, enlarged illustration of the area X in  FIG. 6  with a low power density;  
         [0063]      FIG. 8  shows a sectional illustration of the area X in  FIG. 6  with a high power density of the laser radiation;  
         [0064]      FIG. 9  shows a schematic illustration of a distribution of intensity in the focal point according to  FIG. 6  in the first embodiment;  
         [0065]      FIG. 10  shows a schematic illustration of a relative arrangement of focal point and diaphragm structure in a second embodiment of the exposure unit according to the invention;  
         [0066]      FIG. 11  shows an illustration of the arrangement of the diaphragm structure in the second embodiment of the exposure unit according to the invention on an end surface of the end lens;  
         [0067]      FIG. 12  shows an illustration similar to  FIG. 6  of the second embodiment;  
         [0068]      FIG. 13  shows an illustration similar to  FIG. 6  of a third embodiment;  
         [0069]      FIG. 14  shows an illustration similar to  FIG. 6  of a fourth embodiment;  
         [0070]      FIG. 15  shows an illustration similar to  FIG. 10  of a fifth embodiment of the exposure unit according to the invention and  
         [0071]      FIG. 16  shows an illustration similar to  FIG. 10  of a sixth embodiment of the exposure unit according to the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0072]     One embodiment of a lithography exposure device according to the invention, illustrated in  FIG. 1 , comprises a machine frame designated as a whole as  10  with a base member  12 , on which a table  14  is mounted for movement in two directions extending at right angles to one another, for example, an X direction and a Y direction by means of drives  13   a, b.    
         [0073]     An overhanging arm  16  extending over the table  14  and at a distance from it rises above the base member  12 , an exposure unit  18 , which has a plurality of laser radiation sources  26  combined in a radiation source unit  20 , being arranged in this overhanging arm, as illustrated schematically in  FIG. 1 . A deflection device designated as a whole as  22  adjoins this radiation source unit  20  and this is followed by an optical focusing means which is designated as a whole as  24  and, in the end, images the laser radiation of each laser radiation source  26  as an exposure spot  30  onto a light-sensitive layer  32 , normally a photosensitive coasting layer, which is arranged on the table  14  and applied to a carrier  31  in order to generate in the light-sensitive layer  32  conversion areas  34 , in which the light-sensitive layer  32  is converted from an initial state into an end state and which result altogether in an exposed structure  36  ( FIGS. 2, 3 ). The deflection device  22  and the optical focusing means  24  are also part of the exposure unit  18 .  
         [0074]     Alternatively to the movement of the table  14  in X and Y directions relative to an exposure unit  18  arranged stationarily on the base member  12 , it is provided in a different embodiment of the solution according to the invention, for example, for the table  14  or the exposure unit  18  to be moved only in X direction relative to the base member  12  and, however, for the exposure unit  18  or the table  14  to also be moved in contrast in Y direction relative to the base member  12  or for only the exposure unit  18  to be moved in X and Y directions and the table  14  to be arranged stationarily on the base member  12 .  
         [0075]     As illustrated again in  FIG. 3  in detail but still schematically, the radiation source unit  22  comprises a plurality of laser radiation sources  26  which can, for example, be semiconductor diode lasers or semiconductor lasers with an associated, light-linear, optical frequency conversion, i.e., frequency doubling in order to generate laser radiation with as short a wavelength as possible, preferably in the blue or ultrasonic spectral range.  
         [0076]     The laser radiation  40  generated by the individual laser radiation sources  26  is supplied to the deflection device designated as a whole as  22  in the form of impulse propagation or via light guides.  
         [0077]     The deflection device  22  comprises for the laser radiation  40  of each of the respective laser radiation sources  26  a deflection unit  42 , with which the laser radiation  40  can be deflected in a direction of deflection  44 , as will be described in the following in detail.  
         [0078]     A beam shaping unit  46  is also provided between each of the laser radiation sources  26  and the corresponding deflection units  42 .  
         [0079]     Furthermore, a beam shaping unit  48  is likewise provided between each of the deflection units  42  and the optical focusing means  24  and this unit serves, for example, to generate bundles of laser radiation which are approximately rotationally symmetric prior to their entry into the optical focusing means  24 .  
         [0080]     For its part, the optical focusing means  24  generates the individual image spots  30  associated with each of the laser radiation sources  26  in the light-sensitive layer  32 .  
         [0081]     As illustrated in  FIG. 2 , during the exposure of the light-sensitive layer  32  the table  14  with the light-sensitive layer  32  arranged on it is moved in a direction of exposure movement  50  which can coincide, for example, with the X direction or the Y direction or can also result due to addition of a movement in X and Y directions.  
         [0082]     Furthermore, the direction of exposure movement  50  always extends such that the directions of deflection  44 , in which the laser radiation can be deflected, extend transversely to the direction of exposure movement  50 , wherein a course at right angles is not absolutely necessary but rather a slightly inclined position is likewise possible.  
         [0083]     As a result of the deflection of the laser radiation  40  in the direction of the directions of deflection  44 , the exposure spot  30  resulting from the respective laser radiation  40  is likewise displaceable on the light-sensitive layer  32  in the direction of deflection  44 , namely between an extreme position illustrated by solid lines in  FIG. 2  and an extreme position illustrated by dash-dot lines in  FIG. 2 , wherein both extreme positions determine a width B of strip areas  52 , within which conversions areas  34  can be generated in the light-sensitive layer  32  with the respective exposure spot  30 . The width B corresponds to a multiple of an extension A of the respective exposure spot  30  in the direction of deflection  44 .  
         [0084]     The strip areas  52  are either arranged such that their outer edges  54  and  56  overlap slightly in order to ensure that the conversion areas  34  generated by the exposure spot  30  associated with one of the strip areas  52  can be generated in an interconnected manner with the conversion areas  34  generated by the exposure spot  30  associated with the next closest strip area  52  or are arranged such that the strip areas  52  do not overlap.  
         [0085]     In the case of any overlapping, the conversion area  34   1  can be generated as a continuous conversion area, for example, with the exposure spot  30   a  in the dash-dot position adjoining directly on the edge  56   a  and the exposure spot  30 A in its position adjoining directly on the edge  54 A.  
         [0086]     Furthermore, the conversion area  34   2  can be generated as a continuous conversion area on account of the overlapping of the strip areas  52   a ,  52 A,  52   b  and  52 B, for example, both with the exposure spot  34   a  in a position adjoining the edge  56   a , the exposure spots  30 A and  30   b  in all the positions located between the edges  54 A and  56 A as well as  54   b  and  56   b  and the exposure spot  30 B in its positions located over somewhat more than half the strip area  52 B proceeding from the edge  54 B.  
         [0087]     The individual deflection units  42  operate in the case of the lithography exposure device according to the invention in accordance with the following principle illustrated schematically in  FIG. 4 :  
         [0088]     After passing through the beam shaping unit  46 , which will be described in the following in detail, the laser radiation  40  coming from the respective laser radiation source  26  passes through a first medium  60  which has the index of refraction n 1 . From the first medium  60 , the laser radiation  40  passes into a beam-deflecting spatial area  62 , which is designed, for example, as a prism or half a lens and within which a second medium  64  has a variable, adjustable index of refraction n 2  which is greater than n 1 , and again passes into the first medium with the index of refraction n 1  after passing through the spatial area  62  ( FIG. 4 ).  
         [0089]     As a result, the laser radiation  40  is deflected by the spatial area  62 , on account of the index of refraction n 2  of the second medium  64 , from the original direction  66  into an exiting direction  68  which extends at an angle α in relation to the original direction and so a deflection of the laser radiation  40  by the spatial area  62  takes place.  
         [0090]     The angle α thereby depends on the extent, to which the index of refraction n 2  of the second medium  64  differs from the index of refraction n 1  of the first medium  60 , and so the angle α is also variable at the same time due to variation of the index of refraction n 2 .  
         [0091]     In the case of a spatial area  62  designed as a prism, α:α≈(n 2 −n 1 )φ applies approximately for small angles, wherein φ is the prism angle determining the prismatic spatial area  62 .  
         [0092]     The effectiveness of the spatial area  62  may be increased further when, as illustrated in  FIG. 5 , several consecutive spatial areas  62   a ,  62   b , each consisting of the second medium, are used and the laser radiation  40  passes through them one after the other so that the deflection generated by each individual one of the spatial areas  62   a ,  62   b  may be added together and the exiting direction  68  extends altogether at an angle α to the original direction  66  which represents the sum of the deflections achieved in each of the spatial areas.  
         [0093]     Beam-deflecting spatial areas  62  of this type are described in detail in European patent application No. 02 027 118.5, to which reference is made in full.  
         [0094]     Since the laser radiation  40  extends in the exiting direction  68  at an angle to the original direction  66  after passing through the prism areas  62   a ,  62   b , spatial areas  62 ′ a ,  62 ′ b  having a complementary effect are preferably provided, in addition, in the first embodiment according to  FIG. 5  and these spatial areas again deflect the laser radiation  40  through an angle α in the opposite direction so that, in the end, the exiting direction  68 ′ extends parallel to the original direction  66  but offset in relation to it by a distance D after passing through the spatial areas  62   a ,  62   b  and the complementary spatial areas  62 ′ a ,  62 ′ b.    
         [0095]     As a result, the laser radiation  40  propagating in the exiting direction  68 ′ can be imaged into the exposure spot  30  by the optical focusing means  24  without any additional measures on account of an inclined incidence.  
         [0096]     In the embodiment illustrated in  FIG. 5 , only the elements located in the plane of drawing are illustrated on account of the type of illustration. For example, the laser radiation is generated by the laser radiation sources  26   a ,  26   b  and  26   c  and the laser radiation is guided to the waveguide plate  70   1  via light guides  80   a ,  80   b  and  80   c . The beam shaping units  46   a ,  46   b  and  46   c  for the laser radiation  40   a ,  40   b ,  40   c  from the individual laser radiation sources  26   a ,  26   b  and  26   c , which broaden the laser radiation  40   a ,  40   c  and  40   e  to form a band broadening in the direction of deflection  44 , are provided in this waveguide plate.  
         [0097]     It is possible as a result of the prism units  62  and  62 ′ to offset the laser radiation  40   a ,  40   b  and  40   c  in relation to the original direction  66   a ,  66   b  and  66   c , for example, into the exiting directions  68   a ,  68   b  and  68   c  illustrated which need not be at the same distance from one another in the direction of deflection  44  but can be at different distances.  
         [0098]     The beam shaping unit  48  forms the bundles of radiation  82   a ,  82   b  and  82   c  which then enter the optical focusing means designated as a whole as  24  from the laser radiations  40   a ,  40   b  and  40   c.    
         [0099]     The optical focusing means  24  has, for its part, an ocular  90 , a tube lens  92  and an objective  94 , wherein the ocular reduces the size, for example, ten times and the objective  94 , for example, fifty times.  
         [0100]     In this respect, the tube lens  92  is preferably arranged between the ocular  90  and the objective  94  such that the distance corresponds each time to the focal distance.  
         [0101]     An end lens  96  of the optical focusing means  24  is arranged between the objective  94  and the light-sensitive layer  32  and this, as illustrated in  FIG. 6 , focuses the laser radiation  98  which exits from the objective  94  and is focused by this as well as corresponds each time to one of the bundles of radiation  82   a ,  82   b  or  82   c , in  FIG. 6 , for example, the laser radiation  98   a ,  98   b ,  98   c , onto a corresponding focal point  100   a ,  100   b ,  100   c  within the end lens  96  which borders each time directly on an end surface  102  of the end lens  96  facing the light-sensitive layer  32  so that a laser radiation field  104  propagates from the respective focal point  100 , this field propagating into the light-sensitive layer  32  through a space  106  between the end surface  102  and the light-sensitive layer  32  which is, in particular, less than approximately 100 nm wide, preferably less than approximately 50 nm, even better in the order of magnitude of 10 nm ( FIG. 7 ).  
         [0102]     A laser radiation field  104  of this type propagates at a low power density in the light-sensitive layer  32  with an extension which is substantially greater than the focal point  100 , from which the laser radiation field  104  proceeds, as illustrated in  FIG. 7 . In particular, an increasing penetration of the laser radiation field  104  into the light-sensitive layer  32  leads to an increasing enlargement of the conversion area  34  resulting thereby, in particular with a view to the extension of the exposure spot  30  generated thereby which is at its greatest directly on a surface  108  of the light-sensitive layer  32 .  
         [0103]     For this reason, as illustrated in  FIG. 8 , it is provided in the solution according to the invention for the power density of the laser radiation field  104  proceeding from each focal point  100  in the light-sensitive layer to be in the range of approximately 10 6  to approximately 10 8  W/cm 2  so that the index of refraction n increases by more than 0.1, preferably at least 0.2, within a channel  110  of the light-sensitive layer  32  as a result of the Kerr effect and a reflection of the laser radiation field  104  occurs on account of the index of refraction n increased within the channel  110  in the light-sensitive layer  32  in comparison with the surroundings  112  and, therefore, the laser radiation field  104  is guided within the channel  110  by way of reflection at the transition from the higher index of refraction to the lower index of refraction and, therefore, with an essentially constant cross section of the channel  110  away from the surface of the light-sensitive layer  32  enters this layer and passes through it preferably as far as a substrate  114  penetrating the light-sensitive layer  32 .  
         [0104]     The extension of the exposure spot  30  corresponds approximately to a cross-sectional area of the channel  110  formed in the light-sensitive layer  32  transverse to the direction of propagation  99  of the laser radiation  98 .  
         [0105]     As a result, the extension of the exposure spot  30  and of the conversion area  34  adjoining it is reduced transversely to the direction of propagation  99  of the laser radiation  98  on account of the Kerr effect.  
         [0106]     A further reduction in the extension of the exposure spot  30  may be achieved by using a TM  00  mode for the laser radiation  98  and taking into consideration an alignment of the electric field E thereof determined by the polarization.  
         [0107]     As illustrated in  FIG. 9 , the distribution of intensity  116  of the laser radiation  98  is asymmetric, preferably elliptical, in a plane at right angles to the direction of propagation  99  in the case of a TM  00  mode and, in the case of polarized laser radiation, has in a direction parallel to the electric field E a diameter a which is greater than a diameter b at right angles to the electric field E and so the distribution of intensity  116  is approximately elliptical, as illustrated in  FIG. 9  by means of an elliptical outer contour  118 .  
         [0108]     The diameter a of the distribution of intensity  116  corresponds approximately to  
         a   =     0.6   ⁢       λ   -     NA         ,       
 
 i.e., it is dependent on the wavelength λ of the laser radiation  98  and the numerical aperture NA of the optical focusing means  24 . 
 
         [0109]     In order for the exposure spots  30  to have as slight an extension as possible in a plane extending transversely or at right angles to the direction of propagation  99 , it is possible in a second embodiment of the solution according to the invention to limit the laser radiation field  104 , which proceeds with the distribution of intensity  116  from the focal point  100 , in its extension in the plane extending at right angles to the direction of propagation  99  by means of a diaphragm structure  120  to an extension which is less than the wavelength of the laser radiation  98  itself.  
         [0110]     For example, the diaphragm structure  120  has an opening  122  which is elongated in a longitudinal direction  124  and the longitudinal edges  126   a  and  126   b  of which extending parallel to the longitudinal direction  124  have a distance Ab from one another which is smaller than the wavelength R, is preferably smaller than two thirds of the wavelength and, in particular, is in the order of magnitude of half a wavelength λ of the laser radiation  98 .  
         [0111]     Furthermore, the opening  122  is also limited by transverse side edges  128   a  and  128   b  which are arranged at a distance from one another in the longitudinal direction  124  and this distance is greater than the wavelength λ of the laser radiation  98 , it preferably amounts to a multiple of the wavelength λ of the laser radiation  98 .  
         [0112]     If the diaphragm structure  120  is aligned such that the electric field E extends transversely to the longitudinal side edges  126   a ,  126   b  of the opening  122  and, therefore, transverse to the longitudinal direction  124  of the opening  122 , the laser radiation field  104  passing through the opening  122  may be limited in a transverse direction  125  extending at right angles to the longitudinal direction  124 , namely to an extension which corresponds approximately to the distance Ab between the longitudinal side edges  126   a  and  126   b  of the opening  122 .  
         [0113]     In the most advantageous case, the electric field E of the laser radiation field  104  is aligned such that this is at right angles to the longitudinal side edges  126   a  and  126   b  since, in such a case, the laser radiation field  104  propagating through the opening  122  has the maximum intensity.  
         [0114]     In this case, as illustrated in  FIG. 10 , the diameter a extends at right angles to the longitudinal side edges  126   a ,  126   b  and the diameter b parallel to the longitudinal side edges  126   a ,  126   b  of the opening  122 .  
         [0115]     The exiting laser radiation field  104  therefore has in the transverse direction  125  an extension which corresponds to the distance Ab between the longitudinal side edges  126   a  and  126   b  and in the longitudinal direction  124  an extension which corresponds to the diameter b of the distribution of intensity  116  since the diaphragm structure is not effective in this direction.  
         [0116]     The distance Ab between the longitudinal side edges  126   a ,  126   b  is preferably selected such that it corresponds approximately to the diameter b of the distribution of intensity  116  and, therefore, the resulting focal spot  30  has altogether approximately the same extension in every direction in a plane extending at right angles to the direction of propagation  99 .  
         [0117]     If the diaphragm structure  120  has an opening  122  which is essentially of the same width over the entire longitudinal direction  124 , the laser radiation field  104  passes through at every point along the longitudinal direction  124  with the same intensity for as long as the alignment of the electric field E at right angles to the longitudinal side edges  126   a ,  126   b  does not change. If the alignment of the electric field E is turned out of the position at right angles to the longitudinal side edges  126   a ,  126   b  and forms an angle of smaller than 90° with the longitudinal side edges  126   a ,  126   b , the intensity is reduced since only the part of the laser radiation with an electric field at right angles to the longitudinal side edges  126   a ,  126   b  which results due to vectorial resolution then passes through the opening  122 .  
         [0118]     In the case of an alignment of the electric field E parallel to the longitudinal side edges  126   a ,  126   b , essentially no field  104  passes through the opening  122 .  
         [0119]     A diaphragm structure  120  of this type with the opening  122  may preferably be applied to the end surface  102  of the end lens  96 , for example, by way of evaporation coating of a film, for example, a metal film  130  which does not cover the opening  122  and in the first embodiment is applied directly to the end surface  102 .  
         [0120]     The diaphragm structure  120  may have such an extension in its longitudinal direction  124  that this acts in a limiting manner for the focal points of the laser radiation  40  of several laser radiation sources  26 .  
         [0121]     The longitudinal direction  124  must extend parallel to the direction of deflection  44  so that each exposure spot  30  generated within one of the strip areas  52  is limited in the same way by the diaphragm structure  120 .  
         [0122]     Alternatively thereto, it is, however, also conceivable to provide a separate diaphragm structure  120  for the laser radiation field  104  of each of the individual laser radiation sources  26 .  
         [0123]     With the solution according to the invention, the diaphragm structures  120  are conceived such that the distance Ab between the longitudinal side edges  126   a ,  126   b  is in the dimension of less than 400 nanometers in the case of blue laser radiation and so the exposure spots  30  also have approximately corresponding dimensions. Dimensions of the exposure spots  30  with a diameter in each direction of less than 400 nanometers can therefore be achieved, even better at the most 200 nanometers, and so highly resolved, exposed structures in the submicrometer range can be produced with the lithography exposure device according to the invention.  
         [0124]     Alternatively to the second embodiment, the coating  130  forming the diaphragm structure  120  need not be applied directly to the end surface  102  of the end lens  96  in a third embodiment, illustrated in  FIG. 13 , but rather it is arranged on a carrier  132  which abuts, for its part, with a flat side  134  on the end surface  102  of the end lens  96  and is connected to it in a manner adapted with respect to the index of refraction.  
         [0125]     Such a connection with adaptation of the indices of refraction between the end lens  96  and the carrier  132  is brought about, for example, by way of connection of the carrier  132  to the end lens  96  by means of bonding, blowing together or adhesion, in particular such that a refractive index gradient between the material of the end lens  96  and the material of the carrier  132  is avoided.  
         [0126]     In a fourth embodiment, illustrated in  FIG. 14 , the end surface  102  of the end lens  96 ′ extends only in a central area thereof, namely in the area, in which the focal points  100  are located, whereas the end lens  96 ′ is set back in relation to the end surface  102  in its outer areas  140  facing the light-sensitive layer  32  and surrounding the end surfaces  102  and, therefore, is at a greater distance from the light-sensitive layer  32 .  
         [0127]     In this case, the carrier  132  is also designed such that it abuts only on the end surface  102  of the end lens  96 ′ and is connected to it in a manner adapted with respect to the index of refraction, as described.  
         [0128]     In a fifth embodiment, illustrated in  FIG. 15 , the diaphragm structure  120 ′ is constructed such that it comprises, in addition to the opening  122  extending in the longitudinal direction  124 , openings  142   1 ,  142   2  and  142   3  which intersect it or, where applicable, even more of such intersecting openings  142  which extend at right angles to the longitudinal direction  124  with their longitudinal direction  144   1 ,  144   2  and  144   3  and have longitudinal side edges  146   a  and  146   b  which likewise extend at a distance Ab′ from one another corresponding approximately to the distance Ab while transverse side edges  148   a ,  148   b  likewise have a distance from one another which is considerably greater than the wavelength.  
         [0129]     Intersecting areas  150   1 ,  150   2  and  150   3  therefore result between the opening  122  and the openings  142 .  
         [0130]     If the electric field E of the laser radiation field  104  is now aligned such that it extends at an angle of 45° in relation to the longitudinal direction  124  and to the longitudinal directions  144  and if the direction of deflection  44  extends parallel to the longitudinal direction  124 , the intensity of the laser radiation field  104  proceeding from a focal point  100  is approximately half the maximum intensity for as long as the focal point moves over an area of the opening  122  outside the intersecting areas  150  since, on account of vectorial resolution, the electric field E has at right angles to the longitudinal direction  124  a component which leads to half the intensity passing through the opening  122 .  
         [0131]     If the focal point  100  does, however, reach one of the intersecting areas  150 , half the intensity then passes each time not only through the opening  122  but also the respective opening  142  and so the maximum intensity of the laser radiation field  104  passing through the diaphragm structure  120 ′ can be reached in the region of the respective intersecting area  150 .  
         [0132]     In this respect, if the sensitivity of the light-sensitive layer  132  can be adjusted such that at half the maximum intensity of the laser radiation field  104  no conversion takes place, an exposure spot  30 , which converts the light-sensitive layer within the conversion area  34 , can be generated only at the intersecting areas  150 .  
         [0133]     In a sixth embodiment, illustrated in  FIG. 16 , the diaphragm structure  120 ″ is likewise designed such that it comprises intersecting areas  150  which are arranged so as to follow one another in the direction of deflection  44 .  
         [0134]     These intersecting areas are, however, formed by elongated openings  152 ,  162  which extend at right angles to one another with their longitudinal directions  154 ,  164  and have longitudinal side edges  156   a, b  as well as  166   a, b  which are arranged at a distance Ab″ and Ab′″, respectively, from one another which, as in the preceding embodiments, is smaller than the wavelength R of the laser radiation  98 . Since the longitudinal directions  154  and  164  each extend at an angle of 45° in relation to the direction of deflection, the movement of a focal point  100 , the electric field E of which is aligned at right angles to the direction of deflection  44 , on a path  170  intersecting the intersecting areas  150  results in the focal point  100  being arranged each time so as to cover the openings  152 ,  162  only in the intersecting areas  150  and, therefore, the field  104 , the intensity of which corresponds to the maximum intensity, can form only when the focal point  100  is located over the respective intersecting areas  150 , as explained in conjunction with the intersecting areas  150  in the fifth embodiment.  
         [0135]     As a result, exposure spots  30 , which also lead in the light-sensitive layer to a corresponding conversion thereof within a respective conversion area  34 , can be generated on the light-sensitive layer  32  only in the area of the openings  150 .