Abstract:
A processing facility for manufacturing integrated circuits on semiconductor wafers is provided with at least one radiation generator that generates an EUV (extreme ultraviolet) radiation that is supplied to at least one lithography machine, housed in a factory building, for exposure of the semiconductor wafers. The radiation generator is housed in a building or a building section separate from the factory building. At least one beam guide extends from the building or the building section to the factory building, wherein the EUV radiation is supplied from the building or the building section through the at least one beam guide to the factory building. At least one supply line branches off at an obtuse angle from the at least one beam guide inside the factory building, wherein at least a portion of the EUV radiation is supplied through the at least one supply line to the lithography machine.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention concerns a processing facility for manufacturing integrated circuits (chips) on wafers according to the preamble of claim  1  as well as a perforated panel for a processing facility according to the preamble of claim  15 . 
         [0002]    When manufacturing chips, wafers are used which are exposed to EUV radiation (extreme ultraviolet). This EUV radiation has only a very minimal wavelength so that chips with very small structural widths can be produced. The EUV radiation is released when plasmas are generated by focusing laser beams on tin droplets. This EUV radiation is supplied to the lithography machines by means of which the wafers are exposed in the manufacture of the chips. The lithography machines are located in a factory building. 
         [0003]    The invention has the object to embody the processing facility of the aforementioned kind as well as the perforated panel of the aforementioned kind in such a way that the supply of the EUV radiation to the lithography machine can be designed to be inexpensive and simple. 
       SUMMARY OF THE INVENTION 
       [0004]    This object is solved for the processing facility of the aforementioned kind in accordance with the invention with the characterizing features of claim  1  and for the perforated panel of the aforementioned kind in accordance with the invention with the characterizing features of claim  15 . 
         [0005]    In the processing facility according to the invention, the radiation generator generating the EUV radiation is located in a building, or a building section, that is separate from the factory building. The generated EUV radiation is supplied by at least one beam guide to the factory building. In order to supply the EUV radiation to the lithography machine within the factory building, at least one supply line branches off the beam guide and extends to the lithography machine at an obtuse angle. Since the radiation generator is not located in the factory building, no special features of the factory building have to be taken into consideration when constructing it. Therefore, the building or the building section containing the radiation generator can be erected optimally in regard to the available space within the premises of the processing facility. The beam guide is a vacuum tube in which the EUV radiation is propagated. The vacuum ensures that the EUV rays are not absorbed or only insignificantly absorbed. Coupling out the EUV radiation from the beam guide into the supply line is realized at an obtuse angle by means of optical beam splitters. 
         [0006]    The lithography machine is advantageously housed in a clean room of the multi-story factory building so that the exposure of the wafer can be performed reliably. The stories above and/or below the clean room are advantageously utilized for supply and discharge of clean air as well as for supply and removal of media. The floor between clean room and the story underneath is configured as a perforated panel floor. 
         [0007]    A simple supply of the EUV radiation results when the beam guide is advantageously extending in the area below the lithography machine in the factory building. The area above the lithography machine is then available, for example, for transportation devices with which the lithography machine parts and material can be transported. 
         [0008]    In the clean room there are advantageously several lithography machines which are preferably arranged in a row adjacent to each other. 
         [0009]    When the processing facility is newly constructed, it is expedient to provide the beam guide in such a way that it is extending below the floor slab of the processing building. The beam guide can then be optimally installed with respect to technical construction measures, considerations in regard to the premises and the like. The interior of the factory building is then free from the beam guide so that the factory building can be utilized optimally. 
         [0010]    When the factory building is already existing, then it is advantageous when the beam guide is installed in a story of the factory building below or above the clean room. From here, the appropriate supply lines can then be easily extended to the lithography machine(s). 
         [0011]    In order not to impair by vibrations the EUV radiation that is supplied from the beam guide and/or the supply line and its optical elements, the beam guide is preferably guided in the area of the staff entrance into the factory building. In the area of the staff entrance, shocks that would have a disadvantageous effect on the EUV radiation in the beam guide are not occurring or occurring with negligible effects. 
         [0012]    Advantageously, the material access is then located on the side of the factory building which is opposite the staff entrance. In the area of the material access generally greater vibrations occur that are caused, for example, by transportation vehicles and the like which however have no disadvantageous effect on the EUV radiation due to the great distance from the beam guide. 
         [0013]    When the beam guide is located in the area below the lithography machine, the supply line extends then preferably through a passage in a perforated floor of the clean room. 
         [0014]    Preferably, the perforated floor of the clean room is formed by perforated panels. They constitute pre-manufactured components which, for forming the perforated floor, are placed next to each other and are connected fixedly to each other. 
         [0015]    The perforated panel is provided with at least one, preferably several passages for the supply line. The supply line can therefore be guided in a very simple way through the perforated floor from below to the lithography machine which is standing on the perforated floor. When the perforated panel has in a preferred way several passages, the supply line can then be guided through the best suited passage into the clean room. 
         [0016]    Advantageously, the passage has a rectangular contour. Accordingly, the passage can have a sufficiently large contour so that the supply lines can be passed through without problems. 
         [0017]    The perforated panel has advantageously a quadrangular contour so that the perforated floor can be assembled very simply from the perforated panels. 
         [0018]    Since the supply line is branching off at an obtuse angle from the beam guide, the passage is designed such that it is positioned at an acute angle at a slant to the center plane of the perforated panel. Since the passage advantageously has a rectangular contour, the passage can be provided in the perforated panel in such a way that the supply line can extend at a slant through the perforated panel. 
         [0019]    The supply line is positioned relative to the center plane of the perforated panel advantageously also at an acute angle. 
         [0020]    The perforated panel according to the invention is designed such that the passage for the supply line comprises a rectangular contour and is positioned at an acute angle relative to a center plane of the perforated panel, viewed in a plan view of the perforated panel. As a result of the rectangular configuration of the passage, it can be selected to be so large that, depending on the magnitude of the acute angle, the supply line can be guided through the passage at a slant. 
         [0021]    Preferably, the passage is located centrally within the perforated panel. 
         [0022]    In a preferred embodiment, the perforated panel has at least two adjacently positioned sections of which one section comprises the passage for the supply line and the other section comprises through openings for clean air. The perforated panel in this case is provided with two different passages. Accordingly, in an advantageous way it is thus not necessary to employ different perforated panels for the different passages. 
         [0023]    The sections of the perforated panel have advantageously the same contour and advantageously also the same thickness and fulfill the load and vibration specifications of the other perforated panels. 
         [0024]    The object of the invention results not only from the subject matter of the individual patent claims but also from the disclosures and features disclosed in the drawings and the description. They are claimed to be essential for the invention, even when they are not the subject matter of the claims, inasmuch as individually or in combination they are novel relative to the prior art. 
         [0025]    Further features of the invention result from the additional claims, the description, and the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The invention will be explained in more detail with the aid of embodiments illustrated in the drawings. It is shown in: 
           [0027]      FIG. 1  in schematic illustration and in plan view the map of a processing facility according to the invention for manufacturing integrated circuits on semiconductor wafers; 
           [0028]      FIG. 2  in schematic illustration and in a side view an embodiment of a processing facility according to the invention; 
           [0029]      FIG. 3  in schematic illustration and in a side view a further embodiment of a processing facility according to the invention; 
           [0030]      FIG. 4  in schematic illustration and in a side view a further embodiment of a processing facility according to the invention; 
           [0031]      FIG. 5  in schematic illustration and in a side view a further embodiment of a processing facility according to the invention; 
           [0032]      FIG. 6  in an end view the embodiment according to  FIG. 2 ; 
           [0033]      FIG. 7  a plan view of a floor of the processing facility according to the invention comprised of perforated panels; 
           [0034]      FIG. 8  in an enlarged illustration and in plan view a perforated panel; 
           [0035]      FIG. 9  in schematic illustration the extension of a beam guide through the perforated panel according to  FIG. 8 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0036]    When manufacturing integrated circuits or components (chips) on wafers, lithography machines are used with which the wafers are exposed in a known manner. 
         [0037]      FIG. 1  shows in schematic illustration a conventional facility for manufacturing chips on wafers. The facility comprises a building  1  in which the chips are manufactured. For this purpose, wafers are used which are exposed on the lithography machines  2  in a known way. Since this method is known, it will only be briefly described in the following. A photoresist is applied to the wafer and subsequently exposed. After the exposure process, the wafer is developed. For exposing the wafer, a synchrotron radiation is used which is generated by means of an FEL (free electron laser). This laser is designed such that it can generate radiation in the X-ray range. Such lasers are referred to as FEL or as X-ray laser. With it, extremely energy-rich laser light with a wavelengths of 0.05 to approximately 30 nm can be generated. On the wafer, very fine and narrow structures can be produced by exposure to such a radiation. 
         [0038]    The X-ray laser FEL which is required for generating this X-radiation is housed in a building  3  which is located adjacent to the building  1 . 
         [0039]    The factory building  1  is preferably designed such that a material access side  4  is spatially separated from a staff entrance side  5 . In the illustrated preferred embodiment, the processing building  1  has an approximately rectangular contour. In this case, the material access side  4  and the staff entrance side  5  are provided on the two narrow sides of the factory building  1 . The personnel themselves are housed in an administrative building  6  which is adjacent to a longitudinal side  7  of the factory building  1 . 
         [0040]    Adjacent to the oppositely positioned longitudinal side  8  of the factory building  1 , there are, for example, utility buildings as well as storage buildings which are not identified in detail in  FIG. 1 . 
         [0041]    Since the FEL building  3  is located adjacent to the factory building  1 , the X-radiation generated by the X-ray laser must be supplied through at least one beam guide  9  to the lithography machines  2 . In  FIG. 1 , the beam guide  9  is schematically illustrated. 
         [0042]      FIG. 2  shows an exemplary configuration of the factory building  1 . The lithography machines  2  are located on a floor  10  which is supported by supports  11  on the foundation  12 . The lithography machines  2  are located in a clean room  13  which fulfills the prescribed clean room conditions for exposure of the wafer. The clean room  13  is delimited in the ceiling area by filter fan units  14  which are illustrated in  FIG. 2  only schematically. The filter fan units  14  are designed in a known way and guide the clean air in downward direction into the clean room  13 . The floor  10  of the clean room  13  is provided with through openings for the clean air which, after passing through the openings in the floor  10 , is returned to the filter fan units  14  in a known way. In this context, the clean air can be air-conditioned as well as, if need be, also heated. This treatment of the clean air is known and is therefore not disclosed here in detail. 
         [0043]    Above the filter fan units  14 , there is a support structure  15  along which, for example, a transport crane or the like can be moved with which, for example, the lithography machines  2  can be transported. The support structure  15  is provided with corresponding rails along which the crane can be moved. The support structure  15  as well as the filter fan units  14  arranged underneath are supported by supports  16  and walls  17  in a suitable way on the foundation  12 . 
         [0044]    Below the floor  10  of the clean room  13 , there is a basement story  18  with a floor  19 . It separates the basement story  18  from a further basement story  20  arranged underneath which, as a floor, may comprise the foundation  12  or an additional floor. Within the basement story  18  there are the supports  11  which are advantageously also uniformly distributed across the surface of the floor  19  and support the floor  10  of the clean room  13 . The supports  11  extend advantageously through the basement story  20  and support then the floor  19  on the foundation  12 . 
         [0045]    Since the X-ray laser is located in the building  3 , the X-radiation generated by it must be supplied to the lithography machines  2  in the factory building  1 . The device for generating the X-radiation has large dimensions, for example, a length dimension of approximately 100 m. Accordingly, the building  3  in which this radiation generation source is arranged must be correspondingly large. The X-radiation generated by the FEL is then guided through the at least one beam guide  9  out of the building  3 . The beam guide  9  is a vacuum tube as is known in the art in which the X-radiation can be propagated. In the embodiment according to  FIG. 2 , the beam guide  9  is guided into the lower basement story  20 . In this context, it is expedient when the beam guide  9  is fastened in immediate contact to the foundation  12  or an additional floor of the basement story  20 . As can be seen in  FIG. 6 , the beam guide  9  is arranged such that with its one longitudinal side it is resting on the vertical supports  11 . 
         [0046]    Within the beam guide  9 , the X-radiation is coupled out in a known way through optical devices into supply lines  21  extending at a slant upwardly by means of which the coupled-out proportion of the X-radiation is supplied to the lithography machines  2 . One supply line  21  is provided for each radiation machine  2 , respectively. 
         [0047]    The supply lines  21  adjoin the beam guide  9  at an obtuse angle ( FIG. 2 ). 
         [0048]    The supplied X-ray light is then again coupled out at the respective machine  2  in a known way and is utilized for exposure of the wafer in the machine  2 . 
         [0049]    In a way to be still described, the floors  10 ,  19  are provided with passages through which the supply lines  21  are extending. 
         [0050]    The beam guide  9  has such a length that the machines  2  which are positioned within the clean room  13  can be supplied through the supply lines  21  with the required X-radiation. Since the beam guide  9  extends straight, it is advantageous when the machines  2  are arranged in a row at a spacing adjacent to each other in the clean room  13 . A simple radiation supply of this machine by means of the supply lines  21  is then possible. 
         [0051]    Advantageously, the beam guide  9  is positioned in such a way in the basement story  20  that the basement story can still be utilized optimally for other purposes. For this reason, the beam guide  9  is installed close to one of the narrow sides of the factory building  1 . As shown in  FIG. 6 , the area to the left next to the beam guide  9  can be used indeed for other purposes. 
         [0052]    In the embodiment according to  FIG. 3 , the beam guide  9  is extended into the basement story  18 . Here, the beam guide  9  can be positioned in the same way as in the basement story  20  in accordance with  FIG. 2 . Since the beam guide  9  has a shorter spacing to the lithography machines  2 , the supply lines  21  can be designed correspondingly shorter. This has the advantage that possibly occurring radiation losses can be kept lower. In other respects, the embodiment according to  FIG. 3  is configured in the same way as the embodiment according to  FIG. 2 . 
         [0053]    While in the embodiments according to  FIGS. 2 and 3  the supply lines  21  are extending in the factory building  1  from below to the lithography machines  2 , in the embodiment according to  FIG. 4  the supply of the X-radiation to the lithography machines  2  is realized from above. The beam guide  9  is designed such that it is guided in the area above the lithography machines  2  into the clean room  13 . Expediently, the beam guide  9  which is coming from the FEL building  3  is not arranged immediately above the machines  2  but, in accordance with the preceding embodiments, laterally displaced thereto. In this way, access to the machines  2  is not impaired. The supply lines  21  branch off the beam guide  9  at a slant in downward direction toward the individual machines  2 . The supply lines  21  branch off in accordance with the preceding embodiment at an obtuse angle from the beam guide  9 , viewed perpendicular to the radiation line ( FIG. 4 ). Since the beam guide  9  is extending into the clean room  13 , the supply lines  21  can be short which is advantageous with respect to possibly produced radiation losses. 
         [0054]    In this embodiment, the basement stories  18 ,  20  are available completely for other tasks. 
         [0055]    In other respects, this embodiment is of the same configuration as the preceding embodiments. 
         [0056]      FIG. 5  shows the possibility of providing the beam guide  9  of the FEL building  3  in an area below the factory building  1  instead of extending it into the factory building  1 . The beam guide  9  extends below the floor slab of the foundation  12 . This configuration is advantageous when the factory building  1  as well as the FEL building  3  are constructed at the same time. The preceding embodiments are advantageous when the factory building  1  is already erected and the machines  2  contained therein are to be retrofitted and supplied with X-radiation. 
         [0057]    The supply lines  21  from the beam guide  9  to the exposure machines  2  in the clean room  13 , in contrast to the preceding embodiments, are longer because they must not only extend through the foundation  12  but also through the two basement stories  18 ,  20 . The supply lines  21  adjoin again the beam guide  9 . 
         [0058]    The floors  10 ,  19  of the clean room  13  and of the basement  18  are provided with appropriate through openings for the supply lines  21 . 
         [0059]    Since the beam guide  9  is positioned below the floor slab  12 , it can be optimally positioned such that the supply line  21  can be guided optimally to the machines  2 . 
         [0060]    With the aid of  FIGS. 7 through 9 , the extension of the supply lines  21  through the floor  10  of the clean room  13  will be explained in more detail. The floor  10  is formed by perforated panels  22  which are positioned in a grid pattern. A typical size of the perforated panel  22  is 7.2 m×7.2 m×1 m. Advantageously, each perforated panel  22  is comprised of three sections  22   a ,  22   b ,  22   c . These sections have advantageously the same dimensions. For example, these sections each have a length of 7.2 m, a width of 2.4 m, and a height of 1 m. 
         [0061]      FIG. 7  shows in a plan view the floor  10  which is assembled of perforated panels  22 . In the embodiment, each perforated panel  22  is formed by three identical sections  22   a  to  22   c . As is apparent from  FIG. 7 , the perforated panel sections within the perforated panel  22  can be of the same configuration. This is the case, for example, in the two longitudinal rows  23  and  24  of the floor  10 . In the center row  25  of the floor  10 , perforated panels  22  are provided whose sections are identically designed but also differently. 
         [0062]    In principle, it is also possible that the perforated panel  22  is comprised of only one section. 
         [0063]    The perforated panel  22  according to  FIG. 8  is used in the floor  10  of the clean room at the location where the supply lines  21  are passing through to the machines  2 . The perforated panel  22  has two identically designed sections  22   a ,  22   c  provided with through openings  26 . They are advantageously arranged in rows adjacent and behind each other. The clean air which is flowing in the clean room  13  from top to bottom exits through these openings  26  in downward direction from the clean room  13 . The through openings  26  have advantageously circular contour. 
         [0064]    The central section  22   b  of the perforated panel  22  is provided with passages  27  for the supply lines  21 . The passages  27  are positioned spaced apart form each other. They are identically designed and each have a rectangular contour. In the illustrated embodiment, the passages  27  are arranged such that their longitudinal axes  28  are positioned at an acute angle α to the longitudinal axis  29  of the section  22   b , viewed in a plan view of the perforated panel  22 . The slanted position of the passages  27  is designed such that the supply lines  21  in their slanted position relative to the beam guide  9  can be properly guided through the passages  27 . As is shown in  FIG. 9 , the supply lines  21  are positioned at an angle β relative to the longitudinal center plane  30  of the section  22   b  containing the longitudinal axis  29 . In  FIG. 8 , one of the supply lines  21  extending through the passage  27  is illustrated by dashed lines. In plan view of the perforated panel  22 , the supply line  21  extends parallel to the longitudinal sides of the passages  27 . 
         [0065]    The passages  27  have such a cross-sectional shape that the clean air can flow through the passages  27  past the supply lines  21  in downward direction. In this context, the cross-section of the passages  27  is advantageously so large that in sum total of the passages provided within the central section  22   b  the same air quantity can flow through as through the passages  26  in the sections  22   a  or  22   c.    
         [0066]    Moreover, the perforated panel  22  is designed such that the stiffness of the perforated panel  22  despite the passages  27  fulfills the requirements with regard to vibration resistance and load carrying capacity. 
         [0067]    The supply lines  21  that, like the beam guide  9 , are in the form of the vacuum tubes are attached in a suitable way to the perforated panel  22  such that no vibrations from the perforated panel  22  or from the floor  10  of the clean room  13  are transmitted to the supply lines  21 . In this way it is ensured that the exposure on the machines  2  is guaranteed with the required precision. 
         [0068]    As is shown in  FIG. 7 , the passages  27  in the floor  10  of the clean room  13  are provided only at those locations where the supply lines  21  are extending upward from the basement story  18 . 
         [0069]    In principle, there is also the possibility to employ the individual sections  22   a  to  22   c  as separate parts so that the variability for designing the clean room floor  10  is increased. The sections  22   b  which are provided with the passages  27  for the supply lines  21  can then be arranged at any desired location within the clean room floor  10 . 
         [0070]    The perforated panels  22  or their individual sections are connected to each other in a known way such that the clean air can exit only through the passages  26  as well as the passages  27  in downward direction from the clean room  13 .