Exposure device and exposure method

Abstract

The present invention provides a technique that, in the case of manufacturing a multilayer wiring board, can reduce the shift of patterns between layers and can reduce the difference between the pattern formed on the outermost layer and the design pattern. An exposure device (100) is provided with: a stage (2) for holding a substrate (W) on which a reference mark is formed; a reference mark detection unit (711) that detects the position of a reference mark formed on the substrate (W); a correction amount calculation unit (713) that calculates a correction amount for correcting pattern data (D1) indicating a pattern on the design, on the basis of the amount of offset between the position of the reference mark detected by the reference mark detection unit and the position of the reference mark on the design, and the number of remaining layers, which is the number of remaining layers to be formed on the substrate (W); a correction unit (715) that corrects the pattern data on the basis of the correction amount; and an exposure unit (5) that performs exposure in accordance with the pattern data corrected by the correction unit. The correction amount calculation unit (713) reduces the correction amount as the number of remaining layers decreases.

Description

Technical Field

[0001] The subject matter disclosed in this specification relates to an exposure apparatus and an exposure method. Background Art

[0002] In the past, there is a known multilayer wiring substrate having a multilayer wiring structure formed by laminating a resin layer and a wiring layer on a substrate. In such a multilayer wiring substrate, due to the expansion and contraction of the substrate during the manufacturing process, the wiring patterns drawn on each layer may sometimes be offset.

[0003] For example, in Patent Document 1, coordinate data representing the designed positions (i.e., first positions) of a plurality of fiducial marks provided on a substrate to be exposed and coordinate data representing the actual positions (i.e., second positions) of each of the plurality of fiducial marks are acquired. A physical quantity representing the magnitude of deformation of the substrate to be exposed is derived based on the first and second positions. Furthermore, a correction amount for the offset between the first and second positions is derived for each of the plurality of fiducial marks. Then, based on each of the derived correction amounts, the physical quantity is reduced by a larger amount as it becomes larger, and the coordinate data representing the drawn pattern is corrected based on the reduced correction amount.

[0004] When drawing a drawing pattern, for each layer, the larger the physical quantity representing the size of the deformation of the substrate, the smaller the correction amount, so that the accumulated deformation is reduced each time the layers are stacked, thereby preventing the shape of the drawing pattern drawn on the upper layer from deviating from the shape of the designed drawing pattern, which may cause the installation accuracy of the electronic components to be reduced.

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-199298

[0006] However, as shown in Patent Document 1, even if the correction amount is reduced based on the physical quantity indicating the magnitude of substrate deformation, it is difficult to avoid the accumulation of pattern deviations in each layer. Therefore, the difference between the outermost layer pattern and the designed pattern may become larger. Summary of the Invention

[0007] An object of the present invention is to provide a technology that can reduce pattern deviation between layers and reduce the difference between a pattern formed on an outermost layer and a designed pattern when manufacturing a multilayer wiring board.

[0008] In order to solve the above problems, the first method is an exposure device comprising: a substrate holding unit for holding a substrate on which a reference mark is formed; a reference mark detection unit for detecting the position of the reference mark formed on the substrate; a correction amount calculation unit for calculating the correction amount for correcting pattern data representing a designed pattern based on the offset between the position of the reference mark detected by the reference mark detection unit and the position of the reference mark on the design and the number of remaining layers that should be formed on the substrate, i.e., the number of remaining layers; a correction unit for correcting the pattern data based on the correction amount; and an exposure unit for performing exposure according to the pattern data corrected by the correction unit; the smaller the number of remaining layers, the smaller the correction amount calculation unit makes.

[0009] A second aspect provides the exposure apparatus according to the first aspect, wherein the reference mark is a pattern formed on a surface layer of the substrate.

[0010] A third aspect is the exposure apparatus according to the first aspect or the second aspect, wherein the correction amount calculation unit calculates the correction amount for each of the remaining layers.

[0011] A fourth aspect is the exposure apparatus according to the third aspect, wherein the correction amount calculation unit reduces the correction amount at a constant ratio as the correction amount approaches the outermost layer so that the correction amount of the outermost layer approaches a preset correction amount.

[0012] A fifth method is an exposure device according to the third method or the fourth method, wherein when the offset amount of the substrate having a first layer and a second layer formed on the outside of the first layer deviates from the correction amount calculated for exposing the pattern of the second layer, the correction amount calculation unit recalculates the correction amount for the remaining layer based on the offset amount.

[0013] The sixth method is an exposure method, comprising: step a), calculating a correction amount for correcting pattern data representing a pattern on a design based on an offset between a position of a reference mark formed on a substrate and a position of the reference mark on a design, and the number of remaining layers to be formed on the substrate, i.e., the number of remaining layers; and step b), performing correction based on the correction amount, and performing exposure according to the corrected pattern data; in step a), the smaller the number of remaining layers, the smaller the correction amount.

[0014] According to the exposure apparatus of the first to fifth aspects, the smaller the number of remaining layers, the smaller the amount of correction to the pattern data. Therefore, the size of the formed pattern can be made closer to the designed size as the outermost layer approaches. This reduces pattern shifts between layers and minimizes the difference between the pattern formed on the outermost layer and the designed pattern.

[0015] According to the exposure apparatus of the second aspect, the pattern data of the next layer is corrected based on the pattern of the surface layer of the substrate, thereby reducing the deviation of the pattern between layers.

[0016] According to the exposure apparatus of the fourth aspect, it is possible to further reduce the deviation of the pattern between layers.

[0017] According to the exposure apparatus of the fifth aspect, even in the case of deviation, the deviation of the pattern between layers can be reduced by recalculating the remaining correction amount based on the deviation amount of the reference mark. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a perspective view showing the structure of the exposure apparatus according to the embodiment.

[0019] Figure 2 It is a plan view schematically showing a substrate W exposed in an exposure apparatus.

[0020] Figure 3 Yes Figure 1 A block diagram of the structure of the control unit shown.

[0021] Figure 4 1 is a flowchart showing a method for exposing a substrate W using an exposure apparatus.

[0022] Figure 5 It is a schematic representation of the Figure 4 A cross-sectional view of a multilayer wiring substrate obtained by the exposure process shown.

[0023] Description of Reference Numerals

[0024] 2: Stage (substrate holding part)

[0025] 5: Exposure unit (exposure section)

[0026] 7: Control unit (exposure unit)

[0027] 100: Exposure device

[0028] 711: Fiducial mark detection unit

[0029] 713: Correction amount calculation unit

[0030] 715: Correction Department

[0031] D1: pattern data

[0032] p1 to p6: Circuit pattern (reference mark)

[0033] W: substrate DETAILED DESCRIPTION

[0034] The following describes an embodiment of the present invention with reference to the accompanying drawings. The structural components described in this embodiment are merely illustrative and are not intended to limit the scope of the present invention. In the accompanying drawings, the dimensions and quantities of various components may be exaggerated or simplified as needed for ease of understanding.

[0035] 1. Implementation Method

[0036] Figure 1 This is a perspective view showing the structure of an exposure apparatus 100 according to an embodiment. Exposure apparatus 100 is a substrate processing apparatus that processes a substrate W. It is an apparatus that irradiates the upper surface of substrate W, on which a photosensitive layer W1 containing a photosensitive material such as a resist is formed, with light to create a pattern. Substrate W may be, for example, a semiconductor substrate, a printed circuit board, a color filter substrate, a glass substrate for a flat panel display used in a liquid crystal display or plasma display device, or a substrate for an optical disc.

[0037] Exposure apparatus 100 includes a base 1, a stage 2, a stage moving mechanism 3, a gantry 4, an exposure unit 5, an imaging unit 6, and a control unit 7. Base 1 has a rectangular shape when viewed from above. Base 1 supports stage 2, stage moving mechanism 3, and gantry 4 from below. The exposure unit 5 and imaging unit 6 are supported by gantry 4.

[0038] The stage 2 holds the substrate W. It has an upper surface 2S that serves as a support surface for supporting the substrate W. When viewed from above, the upper surface 2S is a quadrilateral (here, a rectangle). The upper surface 2S is a horizontal surface parallel to the X and Y directions. The substrate W is placed on the upper surface 2S in a horizontal position. A plurality of suction holes are formed on the upper surface 2S. The stage 2 can fix the substrate W on the upper surface 2S by applying negative pressure (suction pressure) to the suction holes. In addition, a chuck for holding the periphery of the substrate W may be provided on the upper surface 2S, and the substrate W may be fixed to the upper surface 2S by using the chuck.

[0039] The stage moving mechanism 3 moves the stage 2 in the main scanning direction (Y direction), the sub-scanning direction (X direction), and the rotational direction (rotational direction about the Z axis (θ direction)). The stage moving mechanism 3 includes a support plate 31, a sub-scanning mechanism 32, a base plate 33, a main scanning mechanism, and a rotation mechanism 35.

[0040] The support plate 31 is arranged on the lower side of the stage 2 and rotatably supports the stage 2. The base plate 33 is arranged on the lower side of the support plate 31 and supports the support plate 31 and the sub-scanning mechanism 32. The sub-scanning mechanism 32 moves the support plate 31 relative to the base plate 33 in the sub-scanning direction, that is, the X direction. The main scanning mechanism 34 moves the support plate 31 relative to the base 1 in the main scanning direction, that is, the Y direction. By moving the base plate 33 in the Y direction, the stage 2 moves in the Y direction. The sub-scanning mechanism 32 and the main scanning mechanism 34 are composed of, for example, a linear motor mechanism including a linear motor and a guide, or a ball screw mechanism including a rotary motor, a ball screw, and a guide. The rotating mechanism 35 is provided on the support plate 31 and rotates the stage 2 around a rotation axis A1 extending in the Z direction. The sub-scanning mechanism 32, the main scanning mechanism 34, and the rotating mechanism 35 operate based on control instructions from the control unit 7.

[0041] The stage 4 includes a pair of legs 41, 41 whose lower portions are fixed to the base 1, and a beam 43 fixed to the upper portions of the legs 41, 41. The legs 41, 41 are spaced apart in the X direction. The stage 2 moves in the Y direction between the legs 41, 41 in the X direction. The exposure unit 5 and the imaging unit 6 are mounted on the beam 43 of the stage 4.

[0042] The exposure unit 5 includes one or more exposure heads 51. In this example, five exposure heads 51 are arranged in the X direction. Each exposure head 51 includes a spatial light modulator 510. The spatial light modulator 510 spatially modulates laser light based on stripe data corresponding to a drawing pattern.

[0043] The exposure unit 5 includes a light irradiation section 53. The light irradiation section 53 irradiates the exposure head 51 with laser light. The exposure head 51 is fixed to the side portion of the beam portion 43 of the stage 4 on the -Y side. The light irradiation section 53 is arranged in the cavity portion within the beam portion 43 of the stage 4. The light irradiation section 53 includes a laser driving section 531, a laser light source 533 (light source), and an illumination optical system 535. By the operation of the laser driving section 531, the laser light source 533 emits laser light toward the illumination optical system 535. The illumination optical system 535 performs operations such as changing the magnification of the laser light incident from the laser light source 533 and uniformizing the light intensity distribution. The laser light emitted from the illumination optical system 535 is irradiated onto the spatial light modulator 510 of each exposure head 51.

[0044] The spatial light modulator 510 spatially modulates the laser light emitted from the light irradiation unit 53 in units of channels, so that the necessary light that helps to depict the pattern and the unnecessary light that is not conducive to the depiction of the pattern are reflected in different directions. In addition, spatially modulating light means changing the spatial distribution of light (amplitude, phase, polarization, etc.). The exposure head 51 irradiates the modulated laser light onto the substrate W moving directly below the exposure head 51. In this way, the untreated substrate W is exposed to the drawing pattern. Specifically, the spatial light modulator 510 is a type of diffraction-type modulation element, namely GLV (Grating Light Valve, a registered trademark of SiliconLight Machines, USA). In addition, the spatial light modulator 510 can also be a DMD (Digital MirrorDevice: digital micromirror device) or the like.

[0045] The imaging unit 6 captures an image including a plurality of reference marks formed on the substrate W. The imaging unit 6 has a plurality of (here, two) cameras 61 and a camera moving unit 63. Each camera 61 has an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). Each camera 61 sends the image data obtained by the imaging to the control unit 7. The camera moving unit 63 moves each camera 61 in the X direction. The camera moving unit 63 is composed of a driving mechanism such as a linear motor mechanism or a ball screw mechanism. The camera moving unit 63 is controlled by the control unit 7. The camera moving unit 63 is fixed to the side of the +Y side of the beam portion 43 of the stage 4. Therefore, each camera 61 moves in the X direction at a position away from the +Y side relative to the stage 4.

[0046] Figure 2 FIG is a schematic top view of a substrate W exposed in the exposure device 100. Figure 2 As shown, the exposure unit 5 irradiates laser light spatially modulated by the spatial light modulator 510. The cross-sectional shape of the laser light irradiated onto the substrate W is rectangular. Figure 2 The irradiation area R1 shown in FIG. 1 represents a rectangular area irradiated with laser light. Figure 2 As shown, five shot regions R1 are simultaneously exposed at equal intervals in the X direction. By spatially modulating the laser light using the spatial light modulator 510, the intensity distribution of the light in the long axis direction (here, the X direction) of the shot region R1 is changed according to the position and shape of the pattern to be drawn.

[0047] The control unit 7 moves the stage 2 in the main scanning direction (Y direction) to move the substrate W in the main scanning direction. Figure 2 Thus, a band-shaped exposure area R3 extending along the main scanning direction is formed on the substrate W. When the five exposure heads 51 are driven, as shown in FIG. Figure 2 As shown, five exposed regions R3 are formed at equal intervals in the X direction. By moving the irradiation region R1 in the main scanning direction, the substrate W is irradiated with laser light from one end to the other end of the region to be exposed.

[0048] When the main scanning movement of the substrate W is completed, the control unit 7 moves the stage 2 in the sub-scanning direction (X direction) by the width of the exposure area R3, thereby moving the substrate W in the sub-scanning direction. Figure 2 The control unit 7 then moves the stage 2 in the main scanning direction again, exposing the unexposed area. By alternating the main scanning and sub-scanning movements of the substrate W in this manner, the entire surface of the substrate W to be exposed is irradiated with laser light.

[0049] Figure 3 Yes Figure 1 1 is a block diagram showing the structure of the control unit 7. The control unit 7 is a computer having a processor 71 such as a CPU (Central Processing Unit) and a memory 73 electrically connected to the processor 71. The memory 73 includes a main storage device such as a ROM (Read-Only Memory) and a RAM (Random Access Memory), and an auxiliary storage device such as an HDD or SSD. In addition, part of the functions of the control unit 7 may be implemented by a dedicated circuit (e.g., an application-specific integrated circuit (ASIC)).

[0050] The memory 73 stores a computer program P. The computer program P can also be provided to the control unit 7 via a non-transitory recording medium such as a magnetic medium, an optical disk, or a semiconductor memory. Alternatively, the computer program P can be provided to the control unit 7 via a network such as the Internet. The memory 73 also stores pattern data D1. The pattern data D1 represents the design to be drawn on the substrate W. When manufacturing a multilayer wiring substrate, the memory 73 stores pattern data D1 for each layer.

[0051] A display 75 and an input device 76 are connected to the control unit 7. The display 75 is a device that displays various information, such as a liquid crystal display. The input device 76 is, for example, a mouse, keyboard, switches, or buttons. Furthermore, by integrating a touch panel into the display 75, the display 75 can be configured as a touch panel display integrated with the input device 76.

[0052] The control unit 7 is electrically connected to each component within the exposure apparatus 100. For example, the control unit 7 is electrically connected to the sub-scanning mechanism 32, the main scanning mechanism 34, the spatial light modulator 510, the laser driver 531, the two cameras 61, and the camera moving unit 63. The processor 71 executes a computer program P to control the operation of each component connected to the control unit 7. Thus, in the exposure apparatus 100, each process for irradiating the substrate W with laser light to create a pattern is sequentially executed.

[0053] like Figure 3 The reference mark detection unit 711, correction amount calculation unit 713, and correction unit 715 are functional blocks implemented by the processor 71 executing the computer program P. The reference mark detection unit 711 uses the image of the substrate W obtained by the camera 61 of the imaging unit 6 to detect the positions of a plurality of reference marks formed on the substrate W. The reference marks have specific shapes formed on the substrate W and can be identified in the image. Specifically, the reference marks are circuit patterns formed on the surface layer (the layer forming the surface) of the substrate W.

[0054] In this embodiment, the reference mark detection unit 711 detects a portion of the circuit pattern on the surface layer of the substrate W as a reference mark. For example, when exposing the second layer of the circuit pattern, a portion of the first layer of the circuit pattern is detected as a reference mark. Alternatively, when forming the third layer of the circuit pattern, a portion of the second layer of the circuit pattern is detected as a reference mark.

[0055] The correction amount calculator 713 calculates a correction amount for each remaining layer that has not yet been formed on the substrate W. Specifically, the correction amount calculator 713 calculates the offset between the positions of the plurality of fiducial marks detected by the fiducial mark detector 711 and the positions of the plurality of fiducial marks as designed. The correction amount calculator 713 then calculates a correction amount for each remaining layer based on the calculated offset and the number of remaining layers (hereinafter referred to as the "remaining layer number"). The smaller the remaining number, the smaller the correction amount.

[0056] Correction unit 715 corrects pattern data D1 based on the correction amount calculated by correction amount calculation unit 713. Control unit 7 controls exposure unit 5 based on pattern data D1 corrected by correction unit 715, i.e., correction data. Consequently, exposure unit 5 draws the corrected pattern on substrate W (more specifically, photosensitive layer W1). Exposure unit 5 and control unit 7 are examples of an "exposure unit."

[0057] The correction amount calculation unit 713 calculates the correction expansion ratio, or the ratio by which pattern data D1 is to be expanded or contracted, as the correction amount. For example, if the correction expansion ratio is -0.1%, the correction unit 715 generates correction data that reduces the scale of pattern data D1 by 0.1%. If the correction expansion ratio is +0.1%, the correction unit 715 generates correction data that extends pattern data D1 by 0.1%.

[0058] Furthermore, to calculate the correction amount, the correction amount calculation unit 713 calculates a "stretching ratio" as the aforementioned offset. Specifically, the stretching ratio refers to the elongation of the measured distance Db (the distance between the detected multiple reference marks) relative to the designed distance Da (the distance between the designed reference marks). If the measured distance Db is greater than the designed distance Da, the stretching ratio Sr is calculated as a positive value. If the measured distance Db is less than the designed distance Da, the stretching ratio is calculated as a negative value. The stretching ratio Sr is calculated, for example, using the following formula.

[0059] Sr=(Db-Da) / Da×100

[0060] <Exposure process using exposure equipment>

[0061] Figure 4 1 is a flowchart showing a method for exposing the substrate W using the exposure apparatus 100 . Figure 4 The exposure method shown is an example of an exposure method for producing a multilayer circuit board.

[0062] In order to mount components on the circuit pattern of the outermost layer of a multi-layer circuit substrate, the scale of the circuit pattern of the outermost layer is preferably roughly consistent with the scale in the design. Therefore, in the exposure device 100, first, based on the input from the user, the correction expansion ratio of the outermost layer is set (step S1). For example, when the correction expansion ratio of the outermost layer is set to 0%, when exposing the circuit pattern of the outermost layer, the original pattern data D1 that has not been corrected for expansion is directly used and directly exposed. In this case, since the pattern is drawn according to the size of the pattern data D1, the outermost layer of the circuit pattern with the same scale as the design can be formed on the substrate W. However, the correction expansion ratio of the outermost layer is not limited to 0%. For example, even if the pattern is drawn with the same scale as the pattern data D1, the circuit pattern actually formed may expand and contract relative to the designed pattern. Taking into account such expansion and contraction of the circuit pattern, the correction expansion ratio of the outermost layer can also be set in advance to a value different from 0%.

[0063] After step S1, the exposure device 100 exposes the first layer pattern, which is the bottom layer (step S2). When exposing the pattern, the substrate W is first aligned to adjust its position. Alignment is performed using alignment marks (not shown) pre-formed on the substrate W. The alignment marks have a shape (e.g., a cross) that makes positioning easy. For example, the alignment marks are formed at the four corners of the substrate W.

[0064] During the exposure phase of the bottommost pattern, no circuit pattern is formed on the substrate W. In other words, no circuit pattern that can be used as multiple reference marks exists. Therefore, the first layer pattern is exposed using the uncorrected pattern data D1.

[0065] Furthermore, when exposing the pattern of the first layer, the expansion and contraction ratio of the substrate W can be determined based on the alignment marks, and the pattern data D1 can be corrected based on this expansion and contraction ratio. In this case, the reference mark detection unit 711 can detect the plurality of alignment marks using an image including the plurality of alignment marks captured by the imaging unit 6, and calculate the expansion and contraction ratio of the substrate W based on the offset between the positions of the detected plurality of alignment marks and the designed positions of the plurality of alignment marks. The correction unit 715 can then correct the pattern data D1 based on the calculated expansion and contraction ratio. By performing exposure using this corrected pattern data, the pattern of the first layer can be exposed in accordance with the expansion and contraction of the substrate.

[0066] After step S2, the substrate W is unloaded from the exposure device 100 and subjected to a process for forming a first layer of circuit patterns in a processing device (not shown). Specifically, the substrate W is subjected to chemical processes such as development, etching, and stripping. Thus, a first layer of circuit patterns corresponding to the exposed pattern is formed on the substrate W. In addition, a process for forming the next layer (here, the second layer) is performed. Specifically, the substrate W is subjected to stacking of prepreg layers, formation of conductive paths, filling of the paths with plating, roughening treatment, and formation of a photosensitive layer W1. In this way, the substrate W with the first layer formed thereon is again conveyed into the exposure device 100.

[0067] When the substrate W returns to the exposure device 100, the exposure device 100 aligns the substrate W. Here, the reference mark detection unit 711 uses the image obtained by the imaging unit 6 to detect the circuit pattern formed on the surface layer (first layer) of the substrate W as a plurality of reference marks. Then, the substrate W is aligned using the positions of the detected plurality of reference marks. In this way, the exposure of the next layer (second layer) can be performed based on the position of the circuit pattern on the surface layer. When the alignment is completed, the correction amount calculation unit 713 calculates the expansion and contraction amount of the first layer (step S3). That is, the correction amount calculation unit 713 calculates the expansion and contraction rate of the first layer based on the positions of the plurality of reference marks (plural parts of the circuit pattern) detected by the reference mark detection unit 711. Furthermore, the correction amount calculation unit 713 calculates the correction expansion and contraction rate of each remaining layer (step S4).

[0068] As described above, the correction amount calculation unit 713 calculates the corrected expansion / contraction ratios for the remaining layers based on the calculated expansion / contraction ratio (offset amount) for the first layer and the number of remaining layers (remaining number of layers). The smaller the number of remaining layers, the smaller the magnitude of the corrected expansion / contraction ratio (correction amount) calculated by the correction amount calculation unit 713. Specifically, the correction amount calculation unit 713 calculates the corrected expansion / contraction ratio for each remaining layer, such that the magnitude of the corrected expansion / contraction ratio decreases toward the outermost layer, and more preferably, the magnitude of the corrected expansion / contraction ratio decreases at a constant rate.

[0069] Table 1 is a diagram showing an example of calculating the correction expansion ratio. In the example shown in Table 1, the expansion ratio of the first layer calculated in step S3 is -0.1%, and the correction expansion ratio of the outermost layer (the sixth layer) set in step S1 is 0%. Therefore, the expansion ratios of the second to fifth layers are -0.08%, -0.06%, -0.04%, and -0.02%, respectively. That is, the size of the correction expansion ratio of each layer is reduced by 0.02% in sequence. In this way, by reducing the size of the correction expansion ratio (correction amount) by a certain proportion, so that the correction expansion ratio of the outermost layer becomes the pre-selected correction expansion ratio, the difference in the size of the circuit pattern between the layers can be reduced, and thus the offset of the circuit pattern between the layers can be reduced.

[0070] Table 1. Calculation example of corrected expansion and contraction

[0071]

[0072] return Figure 4 The exposure device 100 uses the corrected expansion / contraction ratio calculated in step S4 to expose the second layer pattern (step S5). For example, in Table 1, the corrected expansion / contraction ratio for the second layer is -0.08%. Therefore, the correction unit 715 generates correction data that expands or contracts the pattern data D1 by -0.08%. The control unit 7 then performs exposure according to the correction data, exposing the second layer pattern. As a result, a pattern that is contracted by -0.08% from the designed pattern is drawn on the photosensitive layer W1 of the substrate W.

[0073] After step S5 , the substrate W is unloaded from the exposure device 100 and processed in a processing device (not shown) for forming a second layer of circuits. After processing for forming the next layer (here, the third layer), the substrate W is loaded back into the exposure device 100 .

[0074] When the substrate W returns to the exposure device 100, alignment of the substrate W is performed. The correction amount calculation unit 713 then calculates the expansion and contraction rate of the second layer, the surface layer (the layer forming the surface) of the substrate W (step S6). Step S6 is performed in the same manner as step S3. Specifically, alignment of the substrate W is performed using the circuit pattern of the second layer formed on the substrate W as a plurality of reference marks. Furthermore, the expansion and contraction rate of the second layer is calculated based on the detected positions of the plurality of reference marks.

[0075] Next, the correction amount calculation unit 713 determines whether the expansion / contraction ratio of the second layer calculated in step S6 deviates from the corrected expansion / contraction ratio of the second layer indicated by the first corrected expansion / contraction ratio (step S7). Specifically, it determines whether the difference between the corrected expansion / contraction ratio used to expose the second layer and the actual expansion / contraction ratio exceeds a predetermined threshold. If it is determined in step S7 that there is a deviation, the correction amount calculation unit 713 recalculates the expansion / contraction correction amount for each of the remaining layers, i.e., the third layer and thereafter (step S8).

[0076] For example, in the example shown in Table 1, the corrected expansion ratio for the second layer is -0.08%, while the expansion ratio for the second layer actually formed is -0.02%. Because these differences exceed a predetermined threshold (here, 0.02%), the corrected expansion ratios for the third layer and beyond are recalculated. The expansion ratio of the second layer actually formed is used in this recalculation. Specifically, the corrected expansion ratio for the third layer, which will serve as the next layer, is first determined based on the expansion ratio of the second layer (-0.02%) and the previously calculated corrected expansion ratio for the third layer (-0.06%). Here, the corrected expansion ratio for the third layer is set to the midpoint (-0.04%) between the expansion ratios of the second layer (-0.02%) and the third layer. Then, for the remaining layers (the fourth and fifth layers), the corrected expansion ratios for each layer are calculated in the same manner as in step S3, such that the exposure expansion ratio decreases at a certain ratio as the outermost layer is approached. Specifically, the corrected expansion ratios for the fourth to sixth layers are -0.027%, -0.014%, and 0%, respectively. That is, the magnitude of the corrected expansion and contraction rate of each layer decreases by 0.013% in sequence.

[0077] In this way, even if the expansion ratio (shift amount) of the actually formed surface layer deviates from the correction expansion ratio (correction amount) used when the surface layer was exposed, the positional shift between layers can be reduced by recalculating the correction expansion ratio based on the expansion ratio of the surface layer.

[0078] If no deviation is determined in step S7, or after the corrected expansion / contraction ratio is recalculated in step S8, the exposure device 100 uses the corrected expansion / contraction ratio to perform exposure on the next layer, the third layer (step S9). Specifically, similar to step S5, the correction unit 715 generates correction data by correcting the pattern data D1 using the corrected expansion / contraction ratio for the third layer. The control unit 7 then controls the exposure unit 5 using the correction data, thereby drawing the pattern for the third layer.

[0079] Upon completion of step S9, the exposure device 100 determines whether it has completed exposure of all layers (step S10). If exposure of all layers has been completed, the exposure device 100 terminates the process. On the other hand, if there are any unexposed layers, the process returns to step S6 and continues processing in the exposure device 100. In this manner, the exposure device 100 sequentially exposes all layers by repeating steps S6 to S9.

[0080] Figure 5 It is schematically represented by Figure 4 As described above, the exposure device 100 calculates the correction expansion ratio of each remaining layer in such a way that the smaller the number of remaining layers (i.e., the closer to the outermost layer), the smaller the correction expansion ratio. Figure 5As shown, the scale of the circuit patterns p1 to p6 formed on each layer gradually increases as they approach the outermost layer. This gradual increase in the scale of the circuit patterns reduces the misalignment of the circuit patterns between layers. Furthermore, by setting the corrected expansion / contraction ratio of the outermost layer pattern to a preset value, various components can be appropriately mounted relative to the outermost layer circuit pattern.

[0081] Furthermore, the surface circuit pattern is used as a reference mark to calculate the surface expansion and contraction rate, and the correction expansion and contraction amount (correction amount) of the remaining layers is calculated based on this expansion and contraction rate. Therefore, the pattern data of the next layer can be corrected using the surface circuit pattern as a reference. This further reduces the misalignment of the circuit patterns between layers.

[0082] Furthermore, as described above, the reference mark detection unit 711 may detect alignment marks as reference marks instead of detecting the surface circuit pattern. In this case, in steps S5 and S9, multiple alignment marks may be detected, and the expansion / contraction ratio may be calculated based on the offset between the positions of the detected alignment marks and the designed alignment marks.

[0083] While the present invention has been described in detail, the above description is merely illustrative in all respects and the present invention is not limited thereto. It should be understood that numerous unillustrated variations can be envisioned without departing from the scope of the present invention. The various structures described in the above embodiments and variations may be appropriately combined or omitted as long as they do not conflict with each other.

Claims

1. An exposure device, wherein: have: a substrate holding portion for holding the substrate on which the reference mark is formed; a reference mark detection unit that detects a position of the reference mark formed on the substrate; a correction amount calculation unit that calculates a correction amount for correcting pattern data representing a designed pattern based on an amount of displacement between a position of the reference mark detected by the reference mark detection unit and a designed position of the reference mark and a number of remaining layers to be formed on the substrate, i.e., a remaining layer count; a correction unit that corrects the pattern data according to the correction amount; as well as an exposure unit that performs exposure according to the pattern data corrected by the correction unit, The correction amount calculation unit reduces the correction amount as the number of remaining layers decreases.

2. The exposure apparatus according to claim 1, wherein The reference mark is a pattern formed on the surface layer of the substrate.

3. The exposure apparatus according to claim 1 or 2, wherein The correction amount calculation section calculates the correction amount for each of the remaining layers.

4. The exposure apparatus according to claim 3, wherein The correction amount calculation unit reduces the correction amount at a certain ratio as the correction amount approaches the outermost layer so that the correction amount of the outermost layer approaches a preset correction amount.

5. The exposure apparatus according to claim 3 or 4, wherein When the offset amount of the substrate having a first layer and a second layer formed outside the first layer deviates from the correction amount calculated for exposing the pattern of the second layer, the correction amount calculation unit recalculates the correction amount for the remaining layers based on the offset amount.

6. An exposure method, in, include: Step a) calculating a correction amount for correcting pattern data representing a designed pattern based on an amount of displacement between a position of a reference mark formed on a substrate and a position of the reference mark on a design and the number of remaining layers to be formed on the substrate, i.e., the number of remaining layers; and Step b), performing correction according to the correction amount, and performing exposure according to the corrected pattern data; In the step a), the smaller the number of remaining layers is, the smaller the correction amount is.

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