Exposure apparatus

Abstract

The present invention relates to an exposure apparatus, and provides a technique capable of reducing overexposure when forming a double-exposed region. A control section (70) forms a double-exposed region (AJ1) in which a portion of a region irradiated with first drawing light (LBD1) in a first main scan process and a portion of a region irradiated with second drawing light (LBD2) in a second main scan process coincide in a sub-scan direction (D2) by controlling a light modulation element (461). A light amount distribution (G1) of the first drawing light (LBD1) in the sub-scan direction (D2) includes a first attenuation region (Z1) in which the light amount decreases from a first light amount (Q1) to a second light amount (Q2) and a second attenuation region (Z2) in which the light amount decreases toward zero at a different gradient from the first attenuation region (Z1) from the second light amount (Q2) in the double-exposed region (AJ1).

Description

Technical Field

[0001] The subject matter disclosed in this specification relates to exposure apparatus. Background Technology

[0002] Conventionally, to form wiring patterns and other patterns on various substrates such as semiconductor substrates and printed circuit boards, an exposure apparatus is used. This apparatus directly draws the pattern onto a layer of photosensitive material formed on the surface of the substrate. The exposure apparatus generates drawing light by modulating light emitted from a light source based on exposure data representing the pattern to be drawn. Furthermore, the exposure apparatus uses this drawing light to illuminate the substrate held on a worktable, thereby drawing a pattern on the substrate.

[0003] Optical modulation elements that modulate light beams can be categorized into diffractive and reflective types. Examples of diffractive optical modulation elements include GLV (Grating Light Valve: a registered trademark of Silicon Light Machines Corporation, San Jose, California, USA) and PLV (Planar Light Valve). Examples of reflective optical modulation elements include DMD (Digital Micromirror Device).

[0004] In Patent Document 1, main scans and sub-scans are alternately repeated. During the main scan, illuminating light is projected onto the substrate along the main scan direction; during the sub-scan, the substrate moves in a sub-scan direction perpendicular to the main scan direction. This process forms multiple irradiation areas across the entire surface of the substrate. These irradiation areas form overlapping bonding areas (double-exposure areas) in the sub-scan direction. The light modulation element is controlled such that the light intensity in these bonding areas becomes the target light intensity in both exposures.

[0005] During the main scan, the light modulation element is kept off outside the double-exposure area to achieve zero light intensity. However, even with the light modulation element off, the light intensity may not be zero, potentially resulting in slight light leakage. Therefore, overexposure occurs in or around the double-exposure area, exceeding permissible limits, which can lead to exposure defects such as residue defects (defects like unwanted resist residue remaining on the substrate after patterning) or linewidth defects (defects like deviations between the designed and actual linewidths). Furthermore, to prevent such slight light leakage, a light-shielding component is sometimes placed on the light modulation element. However, if the position of the light-shielding component is not properly adjusted, overexposure can also cause exposure defects.

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-46460 Summary of the Invention

[0007] The purpose of this invention is to provide a technique that can reduce overexposure when forming double exposure areas.

[0008] The first approach is an exposure apparatus that directly draws a pattern on a substrate by irradiating it with drawing light. The exposure apparatus includes: a stage that holds the substrate; an exposure unit that irradiates the substrate with drawing light; a moving mechanism that moves the stage relative to the exposure unit in a main scanning direction and a sub-scanning direction orthogonal to the main scanning direction; and a control unit that controls the exposure unit and the moving mechanism. The exposure unit includes: a light source; and a light modulation element that modulates light emitted from the light source into multiple gray levels based on instructions from the control unit. The control unit performs a main scanning process in which the exposure unit irradiates the substrate with the drawing light along the main scanning direction; and a sub-scanning process in which the exposure unit moves relative to the substrate in the sub-scanning direction. The control unit, by controlling the light modulation element, forms a double exposure region in the sub-scanning direction in which a portion of an area irradiated with a first drawing light in the first main scanning process and a portion of an area irradiated with a second drawing light in the second main scanning process overlap. The amount of light from the first drawing light in the sub-scanning direction is distributed in the double exposure area, including a first attenuation region where the amount of light decreases from the first amount to the second amount, and a second attenuation region where the amount of light decreases from the second amount toward zero with a gradient different from that of the first attenuation region.

[0009] According to the exposure apparatus of the first embodiment, in the second embodiment, the exposure unit further includes a light-shielding member that blocks the light so that the light emitted from the light source does not incident on a portion of the light modulation element, thereby forming a light-shielding region at the end of the drawing light. The control unit controls the light modulation element such that in an adjacent region of the first drawing light adjacent to the light-shielding region of the second drawing light, the amount of light is reduced from the first amount of light to the second amount of light.

[0010] According to the exposure apparatus described in the first or second embodiment, in the third embodiment, the control unit corrects the light amount in the double-exposure region based on the exposure data indicating the amount of light to be irradiated onto the substrate, thereby generating corrected exposure data. The control unit then controls the light modulation element based on this corrected exposure data.

[0011] According to any one of the first to third methods of the exposure apparatus, in the fourth method, the light intensity distribution of the first depicting light includes a region between the first attenuation region and the second attenuation region where the light intensity is maintained at the second light intensity.

[0012] According to any one of the first to third methods of the exposure apparatus, in the fifth method, in the light intensity distribution of the first depicting light, the first attenuation region and the second attenuation region are continuous.

[0013] According to the exposure apparatus of the second method, in the sixth method, the light intensity of the first drawing light is distributed in the second attenuation region until the light intensity of the second drawing light is reduced to the light-blocking region.

[0014] According to the exposure apparatus of the sixth method, in the seventh method, the light intensity of the first drawing light is reduced in multiple stages in the second attenuation region until the light-blocking region of the second drawing light.

[0015] According to any one of the first to seventh methods of the exposure apparatus, in the eighth method, the cumulative amount of light irradiated to the double-exposure area by the first main scan process and the second main scan process is less than the amount of light irradiated to the single-exposure area by the first main scan process.

[0016] According to methods one through eight, by setting a first attenuation zone, overexposure caused by light leakage can be reduced. This, in turn, reduces the generation of residue defects or linewidth defects in the double-exposure area.

[0017] According to the second type of exposure apparatus, even when light cannot be blocked by the light-blocking component, resulting in light leakage in adjacent areas, overexposure can be reduced by setting a first attenuation zone.

[0018] By controlling the light modulation element based on the corrected exposure data using a third-party exposure device, the amount of light in the double exposure area can be controlled.

[0019] According to the fourth type of exposure device, by maintaining the light amount at a constant level, poor exposure caused by changes in light amount can be suppressed.

[0020] According to the fifth method of exposure apparatus, by continuously reducing the amount of light, the occurrence of poor exposure caused by changes in the amount of light can be reduced.

[0021] According to the exposure apparatus of the sixth method, the light modulation element is controlled to reduce the amount of light up to the light-shielding component. Therefore, even if the position of the light-shielding component is offset, the cumulative amount of light imparted to the double exposure area can be arbitrarily adjusted. Thus, overexposure in the double exposure area can be avoided.

[0022] According to the exposure apparatus of the eighth method, by reducing the amount of light in the double exposure area, overexposure in the double exposure area can be reduced. Therefore, poor exposure in the double exposure area can be avoided. Attached Figure Description

[0023] Figure 1 This is a schematic perspective view of the exposure apparatus according to the embodiment.

[0024] Figure 2 It is a diagram showing the general structure of the exposure section.

[0025] Figure 3 This is a schematic cross-sectional view showing the general structure of the optical modulation element of a spatial light modulator.

[0026] Figure 4A This is a top view of a spatial light modulator.

[0027] Figure 4B This is the front view of a spatial light modulator.

[0028] Figure 5 This is a control block diagram of the exposure device.

[0029] Figure 6 This is a conceptual representation of the upper surface of a substrate W that has undergone exposure processing.

[0030] Figure 7A It is a diagram showing the light quantity distribution corresponding to the first and second depicting lights.

[0031] Figure 7B It is a graph showing the distribution of light when overexposure occurs.

[0032] Figure 8 This is a graph representing the light distribution of the first modified example.

[0033] Figure 9 This is a graph representing the light distribution of the second modified example.

[0034] Figure 10 This is a graph representing the light distribution of the third modified example.

[0035] Figure 11 This is a graph representing the light distribution of the fourth modified example.

[0036] Figure 12 This is a graph representing the cumulative light quantity in the light quantity distribution of the first revised example. Detailed Implementation

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, in the drawings, for ease of understanding, the dimensions and quantities of various parts are sometimes exaggerated or simplified.

[0038] <1. Implementation Method>

[0039] Figure 1This is a schematic perspective view of the exposure apparatus 1 according to the embodiment. The exposure apparatus 1 is an apparatus that irradiates the upper surface of a substrate W on which a photosensitive material layer (photosensitive layer) such as a resist film is formed, and directly draws a pattern on the upper surface of the substrate W. The substrate W is, for example, a semiconductor substrate, a printed circuit board, a substrate for a color filter, a glass substrate for a flat panel display for a liquid crystal display device or a plasma display device, or a substrate for an optical disc.

[0040] The exposure apparatus 1 includes a base 10, a frame 15, a worktable 20, a worktable moving mechanism 30, an exposure unit 40, and a control unit 70.

[0041] The base 10 is a support platform for supporting the frame 15, the worktable 20, and the worktable moving mechanism 30. The base 10 is fixed to the factory floor or the like. The base 10 has a rectangular shape when viewed from above. Hereinafter, the direction along the long side of the base 10 in the horizontal direction will be referred to as the main scanning direction D1, and the direction along the short side of the base 10 will be referred to as the sub-scanning direction D2. The main scanning direction D1 and the sub-scanning direction D2 are orthogonal to each other.

[0042] The frame 15 is fixed to the upper surface of the base 10. The frame 15 has a pair of feet 151 and a bridging portion 152. The pair of feet 151 are spaced apart in the sub-scanning direction. Each foot 151 extends upward from the upper surface of the base 10. The bridging portion 152 connects the upper ends of the feet 151 to each other in the sub-scanning direction D2. A through-hole 18 is formed between the upper surface of the base 10 and the frame 15, allowing the substrate W to pass through in the main scanning direction D1.

[0043] The stage 20 holds the substrate W horizontally. The stage 20 includes a first stage 21 and a second stage 23. The first stage 21 is movable along the main scanning direction D1. The first stage 21 has a flat, plate-like shape. Viewed from above, the first stage 21 is a rectangle smaller than the base 10. The first stage 21 is positioned above the base 10 in a generally horizontal orientation. The second stage 23 is movable along the sub-scanning direction D2. The second stage 23 has a flat, plate-like shape. Viewed from above, the second stage 23 is a rectangle smaller than the first stage 21. The second stage 23 is positioned above the first stage 21 in a generally horizontal orientation.

[0044] The table movement mechanism 30 is a mechanism for moving the table 20. The table movement mechanism 30 includes a first movement mechanism 31 and a second movement mechanism 33. The first movement mechanism 31 is a mechanism for moving the first table 21 relative to the base 10 and the frame 15 along the main scanning direction D1. The first movement mechanism 31 is a linear motor mechanism having a pair of guide rails and a linear motor. The pair of guide rails are tracks for guiding the first table 21 in the main scanning direction D1. The pair of guide rails are spaced apart on the upper surface of the base 10 in the secondary scanning direction D2 and extend linearly along the main scanning direction D1. The linear motor has a stator disposed on the upper surface of the base 10 and a moving member fixed to the lower surface of the first table 21. When a control signal is supplied to the linear motor from the control unit 70, the moving member moves along the stator in the main scanning direction D1 due to the magnetic attraction and repulsion forces generated between the stator and the moving member. As a result, the first table 21 moves relative to the base 10 in the main scanning direction D1. Furthermore, the drive source of the first moving mechanism 31 is not limited to a linear motor. The first moving mechanism 31 can also be, for example, a mechanism that converts the rotary motion of a servo motor into linear motion via a ball screw.

[0045] The second moving mechanism 33 is a mechanism that moves the second worktable 23 relative to the first worktable 21 in the sub-scanning direction D2. The second moving mechanism 33 is a linear motor mechanism having a pair of guide rails and a linear motor. The pair of guide rails are spaced apart in the Y-axis direction on the upper surface of the first worktable 21. Each guide rail extends in a straight line along the sub-scanning direction D2. The pair of guide rails are tracks for guiding the second worktable 23 in the sub-scanning direction D2. The linear motor, for example, includes a stator disposed on the upper surface of the first worktable 21 and a moving member fixed to the lower surface of the second worktable 23. However, the second moving mechanism 33 is not limited to a linear motor mechanism; for example, it could also be a ball screw mechanism.

[0046] The substrate W is supported on the upper surface of the second worktable 23 in a generally horizontal position. The second worktable 23 may also have clamping pins for fixing the substrate W, or multiple suction holes for adsorbing the substrate W. In this case, the suction holes are connected to a negative pressure source flow path that generates a low pressure lower than atmospheric pressure, such as a suction pump. Alternatively, the negative pressure source may be factory equipment. The exposure apparatus 1 moves the substrate W in the main scanning direction D1 and the sub-scanning direction D2 by actuating the first moving mechanism 31 and the second moving mechanism 33.

[0047] Exposure unit 40 is a unit that exposes the substrate W held on the second worktable 23. For example... Figure 1 As shown, the exposure unit 40 includes multiple (four in this case) exposure heads 41, an illumination optical system 43, and a laser oscillator 45 (light source). Each exposure head 41 is fixed to the bridging portion 152 of the frame 15. The multiple exposure heads 41 are arranged at equal intervals along the sub-scanning direction D2.

[0048] Figure 2 This diagram shows a schematic structure of the exposure unit 40. The laser oscillator 45 is the light source that emits the laser LB used for drawing. The laser LB emitted from the laser oscillator 45 is guided to the exposure head 41 via the illumination optics system 43. Alternatively, an LED (Light Emitting Diode) or a mercury lamp can be used as the light source instead of the laser oscillator 45. The illumination optics system 43 includes a collimating lens that converts the laser LB from the laser oscillator 45 into parallel light, and a cylindrical lens that converts it into linear light.

[0049] like Figure 2 As shown, the exposure head 41 includes a spatial light modulator 46 and a projection optics system 47. The spatial light modulator 46 spatially modulates the laser LB guided from the laser oscillator 45 on a channel-by-channel basis, causing the necessary light (0th-order diffraction light) that helps in pattern drawing and the useless light (±1st-order or higher diffraction light (scattered light)) that does not help in pattern drawing to reflect in different directions. That is, the spatial light modulator 46 spatially modulates the laser LB to form pattern light corresponding to the pattern that should be drawn on the substrate W. The projection optics system 47 directs the formed pattern light toward the exposure position Pe on the substrate W, which moves directly below the exposure head 41. Thus, the substrate W is exposed by the pattern light, thereby directly drawing a pattern at the exposure position Pe on the upper surface of the substrate W. Spatially modulating the laser LB means changing the light intensity distribution of the laser LB. In this embodiment, a GLV can be used as the exposure head 41. However, other diffraction-type light modulators such as a PLV can also be used for the exposure head 41.

[0050] Figure 3 This is a schematic cross-sectional view showing the outline structure of the optical modulation element 461 of the spatial light modulator 46. Figure 3 The image shows three different states of the optical modulation element 461 on the left, center, and right sides. The optical modulation element 461 has a bottom electrode 81, a plurality of fixed strips 82, and a plurality of movable strips 83. The bottom electrode 81 has, for example, a flat plate shape. The plurality of fixed strips 82 and the plurality of movable strips 83 extend along the length direction.

[0051] exist Figure 3 In order to illustrate the positional relationship of the various parts in the optical modulation element 461, an orthogonal xyz coordinate axis is defined. Here, the direction in which the plurality of fixed strips 82 and the plurality of movable strips 83 are arranged is defined as the x-direction, and the length direction of each fixed strip 82 and each movable strip 83 is defined as the y-direction. In addition, the direction orthogonal to the surface of the fixed strips 82 and the movable strips 83 is defined as the z-direction. Each fixed strip 82 and each movable strip 83 is located on the same side of the z-direction and is arranged above the bottom electrode 81.

[0052] The arrangement direction of the multiple fixed strips 82 and the multiple movable strips 83, i.e., the x-direction, is approximately parallel to the sub-scanning direction D2. The fixed strips 82 and the movable strips 83 are alternately arranged along the x-direction, which is parallel to the sub-scanning direction D2 in the horizontal direction. That is, the optical modulation element 461 is arranged along the arrangement direction, which is parallel to the sub-scanning direction D2 in the horizontal direction.

[0053] The laser LB emitted from the laser oscillator 45 is incident from one side in the z-direction onto the +z side surfaces of each fixed band 82 and each movable band 83 via a reflector in the illumination optics system 43. Hereinafter, for ease of explanation, the laser LB incident on the fixed band 82 and the movable band 83 will also be referred to as "incident light Li". The fixed band 82 has a fixed reflecting surface 82S, and the movable band 83 has a movable reflecting surface 83S. The fixed reflecting surface 82S and the movable reflecting surface 83S are respectively precision-machined into a planar shape. The plurality of fixed reflecting surfaces 82S and the plurality of movable reflecting surfaces 83S form the focusing surface 461S of the light modulation element 461.

[0054] The fixed reflective surface 82S is fixed at a predetermined distance relative to the bottom electrode 81. Furthermore, the movable reflective surface 83S is configured to move in directions approaching or moving away from the bottom electrode 81, depending on the applied voltage (driving voltage). That is, the movable reflective surface 83S can move relative to the fixed reflective surface 82S in the z-direction orthogonal to the movable reflective surface 83S.

[0055] The displacement of the movable reflective surface 83S is adjusted according to the magnitude of the potential difference generated between the movable band 83 and the bottom electrode 81 due to the driving voltage. For example, as Figure 3 As shown on the left, when the height difference h between the fixed reflecting surface 82S and the movable reflecting surface 83S is zero, the light reflected by the fixed reflecting surface 82S and the light reflected by the movable reflecting surface 83S are in the same phase. Therefore, these lights are reflected from the light modulation element 461 as the 0th order diffracted light Lr.

[0056] More specifically, when the wavelength of the incident light Li is set to λ, and the optical path difference (=2h) between the light reflected by the fixed reflecting surface 82S and the light reflected by the movable reflecting surface 83S is an integer multiple of the wavelength λ (=n×λ (n is an integer greater than or equal to zero)), the light reflected by the fixed reflecting surface 82S and the light reflected by the movable reflecting surface 83S are in phase. In this case, the 0th order diffracted light Lr is emitted from the optical modulation element 461.

[0057] In addition, such as Figure 3As shown in the center, when the optical path difference (=2h) between the light reflected by the fixed reflecting surface 82S and the light reflected by the movable reflecting surface 83S is an odd multiple of half the wavelength λ / 2, the light reflected by the fixed reflecting surface 82S and the light reflected by the movable reflecting surface 83S are out of phase and cancel each other out. Therefore, the light modulation element 461 does not emit reflected light in the vertical direction, but emits light in the oblique direction, that is, diffracted light (scattered light Ld) of ±1 order or higher.

[0058] In addition, such as Figure 3 As shown on the right, when the optical path difference (=2h) between the light reflected by the fixed reflecting surface 82S and the light reflected by the movable reflecting surface 83S is not an integer multiple of the wavelength λ and not an odd multiple of half the wavelength λ / 2, a portion of the incident light Li is emitted as the 0th order diffracted light Lr, and the remainder is emitted as diffracted light of ±1st order or higher (scattered light Ld) in the tilted direction. That is, depending on the magnitude of the height difference h, the 0th order diffracted light Lr, which is weaker than the incident light Li, is emitted from the optical modulation element 461. Thus, by changing the driving voltage, the intensity of the 0th order diffracted light Lr (or the intensity of the scattered light Ld) in the optical modulation element 461 can be adjusted. As a result, the optical modulation element 461 can modulate the laser LB emitted from the laser oscillator 45, which serves as the light source, into multiple gray levels.

[0059] The projection optical system 47 reduces the laser LB (0th-order diffracted light Lr) modulated by the light modulation element 461 of the spatial light modulator 46 and projects it toward the substrate W. For example... Figure 2 As shown, the projection optical system 47 reduces the laser LB (0th-order diffracted light Lr) modulated by the spatial light modulator 46, and images it on the upper surface of the substrate W to which the resist film is formed. That is, the exposure unit 40 illuminates the substrate W with the laser LB modulated by the spatial light modulator 46 via the projection optical system 47. In other words, the exposure device 1 directly illuminates the substrate W with the 0th-order diffracted light Lr emitted from the spatial light modulator 46 via the projection optical system 47 to perform the patterning. Furthermore, diffracted light of ±1st order or higher (scattered light Ld) emitted from the light modulation element 461 is blocked by the aperture 47a provided by the projection optical system 47. That is, diffracted light of ±1st order or higher (scattered light Ld) does not exit from the projection optical system 47 and does not contribute to the patterning.

[0060] Therefore, in the following explanation, Figure 3 The state shown on the left or right side is called the "on state". Figure 3 The state shown in the center is called the "off state". The "on state" is the state in which laser LB (0th order diffracted light Lr) is irradiated from the spatial light modulator 46 toward the substrate W, drawing a pattern on the upper surface of the substrate W. However, in Figure 3In the state shown on the right, the intensity of the laser LB (0th order diffracted light Lr) irradiated from the spatial light modulator 46 onto the substrate W is compared to... Figure 3 The state shown on the left is small. The "off state" is the state in which laser LB (0th order diffracted light Lr) is not irradiated from the spatial light modulator 46 and no pattern is drawn on the upper surface of the substrate W. The "on state" and "off state" are achieved by adjusting the magnitude of the driving voltage applied to the movable strip 83 by controlling the spatial light modulator 46.

[0061] The smallest unit controlling the "on" and "off" states is called channel C. Channel C consists of a set of fixed strips 82 and movable strips 83. The drive voltage of each movable strip 83 in the optical modulation element 461 can be set individually. Therefore, control can be performed between the "on" and "off" states for each channel C. Alternatively, channel C can also consist of multiple sets of fixed strips 82 and movable strips 83.

[0062] Figure 4A This is a top view of the spatial light modulator 46. Figure 4B This is a front view showing the spatial light modulator 46. (Example) Figure 4A and Figure 4B As shown, the spatial light modulator 46, in addition to the light modulation element 461, also includes a glass slide 463 and two light-shielding components 465. The glass slide 463 is located away from the light modulation element 461 towards the +z side. The glass slide 463 is transparent. The glass slide 463 allows the laser LB incident on the light modulation element 461, as well as the laser LB reflected by the light modulation element 461 (0th order diffracted light Lr and scattered light Ld), to be transmitted.

[0063] The light-blocking component 465 is a component that suppresses light transmission, for example, made of metal. The light-blocking components 465 are respectively disposed on the surface of the glass slide 463 on the +z side. One of the two light-blocking components 465 is disposed on the +x side end of the glass slide 463, and the other is disposed on the -x side end of the glass slide 463.

[0064] The light-shielding member 465 blocks the laser LB, preventing the laser LB emitted from the laser oscillator 45 (light source) from incident on a portion of the light modulation element 461 in the spatial light modulator 46. More specifically, it blocks the laser LB incident on multiple channels C located at the ends of the light modulation element 461. Thus, the light-shielding member 465 forms a light-shielding region at the ends of the drawing light LBD irradiating the substrate W. The multiple channels C covered by the light-shielding member 465 become channels (virtual bands) that do not contribute to the formation of the drawing light. The positional relationship between the light-shielding member 465 and the light modulation element 461 is adjusted, for example, when the exposure apparatus 1 is started.

[0065] Figure 5This is a control block diagram of the exposure apparatus 1. The control unit 70 is a device for controlling the operation of various parts of the exposure apparatus 1. The control unit 70 is a computer including a processor 71, a memory 73, and an auxiliary storage device 75. The memory 73 and the auxiliary storage device 75 are electrically connected to the processor 71 via bus wiring (not shown).

[0066] Processor 71 includes a CPU (Central Processing Unit) or an MPU (Microprocessing Unit). Processor 71 may include a general-purpose computer, a dedicated arithmetic unit, and a GPU (Graphics Processing Unit). Dedicated arithmetic units include, for example, ASICs (Application Specific Integrated Circuits).

[0067] Memory 73 includes a main storage device. The main storage device may include, for example, a semiconductor memory such as RAM (Random-Access Memory). Memory 73 may include non-volatile memory such as ROM (Read-Only Memory) for storing programs and data. Auxiliary storage device 75 includes a solid-state drive (SSD) or a hard disk drive (HDD). Auxiliary storage device 75 may include removable media.

[0068] The auxiliary storage device 75 stores a computer program PG1. The computer program PG1 includes a program for controlling the operation of the exposure apparatus 1. The processor 71 reads the computer program PG1 stored in the auxiliary storage device 75 into the memory 73. The processor 71 executes the computer program PG1 read into the memory 73. As a result, the control unit 70 performs various processes.

[0069] The control unit 70 is electrically connected to the input unit 77 and the output unit 78. The input unit 77 inputs instructions or data corresponding to the operator's operation to the control unit 70. The input unit 77 includes a keyboard 771 and a mouse 773. The input unit 77 may include a reading device for reading data from a removable medium.

[0070] The output unit 78 includes a display 781 that displays various information. The display may be, for example, a liquid crystal display (LCD) or an organic EL (Electroluminescent) display. The input unit 77 may also include a touch panel sensor that overlaps with the display surface of the display 781. The output unit 78 may include a speaker, a printer, or a lamp.

[0071] The auxiliary storage device 75 stores exposure data ED1. Exposure data ED1 is data that represents the shape of the pattern to be depicted and specifies the amount of exposure required to form the pattern. Exposure data ED1 is, for example, data obtained by rasterizing vector data generated using CAD (Computer Aided Design) or similar methods.

[0072] The control unit 70 is electrically connected to the first moving mechanism 31 and the second moving mechanism 33 of the stage moving mechanism 30, as well as the laser oscillator 45 and the optical modulation element 461. The control unit 70 controls the first moving mechanism 31, the second moving mechanism 33, the laser oscillator 45, and the optical modulation element 461 based on the exposure data ED1 according to the computer program PG1. This performs the exposure process of the substrate W in the exposure apparatus 1.

[0073] Figure 6 This conceptually represents the upper surface of a substrate W that has undergone exposure processing. For example... Figure 6 As shown, while the substrate W is held on the worktable 20, the control unit 70 alternately performs the main scanning process of the exposure unit 40 irradiating the drawing light LBD along the main scanning direction D1 and the sub-scanning process of the exposure unit 40 moving relative to the substrate W in the sub-scanning direction D2.

[0074] During the main scanning process, the control unit 70 activates the first moving mechanism 31, causing the substrate W to move relative to the exposure head 41 in the main scanning direction D1. As a result, the substrate W moves relative to the exposure head 41 in the main scanning direction D1. When viewed from the stage 20, as... Figure 6 As indicated by the middle arrow Ar1, the exposure head 41 traverses the substrate W along the main scanning direction D1. Furthermore, during the traversal of the substrate W, the exposure head 41 illuminates the substrate W with a spatially modulated drawing light LBD based on exposure data ED1. Additionally, the spatial light modulator 46 modulates the drawing light LBD illuminated onto the substrate W based on instructions (control signals) from the control unit 70. Through this main scanning process, a strip-shaped exposure region A11 extending along the main scanning direction D1 is formed on the upper surface of the substrate W.

[0075] During the sub-scanning process, the control unit 70 activates the second moving mechanism 33, causing the substrate W to move a predetermined distance relative to the exposure head 41 in the sub-scanning direction D2. As a result, the substrate W moves a predetermined distance relative to the exposure head 41 along the sub-scanning direction D2. When viewed from the substrate W, as... Figure 6 As indicated by the middle arrow Ar2, the exposure head 41 moves a predetermined distance along the sub-scanning direction D2. This predetermined distance is smaller than the width of the exposure area A11 along the sub-scanning direction D2.

[0076] When the sub-scan processing ends, such as Figure 6As indicated by the middle arrow Ar3, the control unit 70 performs the main scan process again. As a result, a strip-shaped exposure area A12 is formed along the main scan direction D1. In this way, the control unit 70 patterns the exposure target area of ​​the substrate W by alternately performing the main scan process and the sub-scan process.

[0077] Hereinafter, the main scanning process that forms the exposure area A11 will be referred to as the "first main scanning process". Furthermore, the drawing light LBD that is illuminated in the first main scanning process will be referred to as the "first drawing light LBD1". Hereinafter, the main scanning process that forms the exposure area A12 will be referred to as the "second main scanning process". Furthermore, the drawing light LBD that is illuminated in the second main scanning process will be referred to as the "second drawing light LBD2".

[0078] The control unit 70 forms a single-exposure region AS1 and a double-exposure region AJ1 by performing two main scan processes. The single-exposure region AS1 is the region exposed only once by one of the first drawing light LBD1 and the second drawing light LBD2. The double-exposure region AJ1 is the region where a portion of exposure region A11 and a portion of exposure region A12 overlap in the sub-scanning direction D2. By providing the double-exposure region AJ1 at the boundary of exposure regions A11 and A12, uneven exposure and exposure streaks at the boundary can be suppressed.

[0079] Figure 7A G1 and G2 represent the light quantity distributions corresponding to the first depicting light LBD1 and the second depicting light LBD2, respectively. Figure 7A In the diagram, the horizontal axis represents the position on the substrate W in the sub-scanning direction D2, and the vertical axis represents the light intensity.

[0080] like Figure 7A As shown, light-shielding members 465 are disposed at both ends of the light modulation element 461. Therefore, light-shielding regions A2 with completely zero light intensity are formed at both ends of the depicting light LBD. When the light-shielding members 465 are disposed according to the design, as... Figure 7A As shown, the amount of light from the drawing light LBD in the double-exposure region AJ1 is reduced at a constant gradient from Q1 (the first amount of light) to zero in the shaded region A2. Thus, by performing two main scans, the double-exposure region AJ1 is given the same amount of light as the single-exposure region AS1. The channel C associated with this double-exposure region AJ1 consists of, for example, 40 channels.

[0081] Here, channel C, covered by the light-shielding member 465, is typically controlled to be in an open state. However, even when channel C is controlled to be in an open state, it is difficult to achieve a completely zero light intensity. Assuming the light-shielding member 465 is offset, light leaking from the open channel C may illuminate the substrate W, potentially leading to overexposure. Regarding this overexposure, refer to... Figure 7B Please provide a detailed explanation.

[0082] Figure 7B G1 and G2 represent the light distribution that causes overexposure. For example... Figure 7B As shown, due to the positional offset of the light-shielding component 465, a small amount of light ΔQ is generated in the adjacent region A3, which is adjacent to the light-shielding region A2 of the first drawing light LBD1. Similarly, a small amount of light ΔQ is also generated in the adjacent region A3 in the second drawing light LBD2. In this case, through two main scan processes, a light amount of Q1+ΔQ is irradiated into each adjacent region A3, resulting in overexposure of ΔQ. If the overexposure exceeds the allowable range, exposure defects such as residue defects or linewidth defects will occur at the boundary of the exposed regions A11 and A12.

[0083] Therefore, in this embodiment, the control unit 70 controls the light modulation element 461 to reduce the amount of light in the double-exposure region AJ1, thereby reducing overexposure. Specifically, the control unit 70 corrects the exposure data ED1 and generates corrected exposure data ED2. Furthermore, based on the corrected exposure data ED2, the control unit 70 controls the light modulation element 461 to generate corrected light amount distributions G1 and G2 in the double-exposure region AJ1. Hereinafter, examples of corrected light amount distributions G1 and G2 will be described.

[0084] Figure 8 The light intensity distributions G1 and G2 represent the first modified example. In this first modified example, the light intensity distribution G1 includes a first attenuation region Z1, which decreases from Q1 (first light intensity) to Q2 (second light intensity), and a second attenuation region Z2, which decreases from Q2 to zero light intensity (off state), inside the double exposure region AJ1. Furthermore, the light intensity distribution G1 in the first modified example includes a constant light intensity region Z3, where the light intensity is maintained at Q2, between the first attenuation region Z1 and the second attenuation region Z2. The light intensity distribution G2 of the second depicting light LBD2 is also similar to the light intensity distribution G1, including the first attenuation region Z1 and the second attenuation region Z2, and the constant light intensity region Z3 located between the first attenuation region Z1 and the second attenuation region Z2, inside the double exposure region AJ1.

[0085] In the first modified example, in the double-exposure region AJ1, the light intensity decreases from Q1 to zero (off state) in two stages. The gradient of light intensity change in the second attenuation region Z2 is different from the gradient of light intensity change in the first attenuation region Z1. Specifically, the gradient of the second attenuation region Z2 is smaller than the gradient of the first attenuation region Z1. That is, in the second attenuation region Z2, the light intensity decreases more slowly than in the first attenuation region Z1.

[0086] If we consider the light intensity distribution G1 of the first drawing light LBD1, the first attenuation region Z1 of the light intensity distribution G1 is set inside the adjacent region A3 of the second drawing light LBD2. That is, the control unit 70 controls the light modulation element 461 so that the light intensity in the region of the first drawing light LBD1 that overlaps with the adjacent region A3 of the second drawing light LBD2 is reduced from Q1 to Q2. Furthermore, if we consider the light intensity distribution G2 of the second drawing light LBD2, the first attenuation region Z1 of the light intensity distribution G2 is set inside the adjacent region A3 of the first drawing light LBD1. That is, the control unit 70 controls the light modulation element 461 so that the light intensity in the region of the second drawing light LBD2 that overlaps with the adjacent region A3 of the first drawing light LBD1 is reduced from Q1 to Q2. The channel C that contributes to the first attenuation region Z1 and the reduction amount (=Q1-Q2) in the first attenuation region Z1 are appropriately optimized, for example, through a pre-exposed exposure process.

[0087] In this way, by setting the first attenuation zone Z1, overexposure caused by light leakage can be reduced. As a result, poor exposure in the double exposure zone AJ1 can be reduced. In addition, by setting the first attenuation zone Z1 to overlap with the adjacent zone A3, overexposure can be suppressed even if the position of the light-shielding component 465 is offset.

[0088] Alternatively, double exposure areas AJ1 can be formed at both ends of the exposure areas A11 and A12. In this case, such as Figure 8 As shown, a first attenuation region Z1, a second attenuation region Z2, and a constant light intensity region Z3 are respectively set at both ends of the light intensity distributions G1 and G2.

[0089] Figure 9 Let G1 and G2 represent the light intensity distributions of the second modified example. These distributions include a first attenuation region Z1 where the light intensity decreases at a constant gradient from Q1 to Q2, and a second attenuation region Z2 where the light intensity decreases at a constant gradient from Q2 to zero. In this second modified example, the first attenuation region Z1 and the second attenuation region Z2 are continuous, and there is no region where the light intensity remains constant at the level of Q2 (constant light intensity region Z3), which differs from the first modified example.

[0090] According to this second modified example, the light intensity changes more smoothly than in the first modified example at the boundary between the first attenuation region Z1 and the second attenuation region Z2 inside the double exposure region AJ1. Therefore, exposure defects such as linewidth variations caused by changing the light intensity in two stages can be reduced inside the double exposure region AJ1.

[0091] Figure 10 The light intensity distributions G1 and G2 represent the third modified example. In this third modified example, similar to the second modified example, a first attenuation region Z1 and a second attenuation region Z2 are continuously located inside the double exposure region AJ1. However, in the third modified example, the light intensity decreases at a constant gradient up to the boundary between the light-blocking region A2 and the exposure regions A11 and A12. Therefore, considering the light intensity distribution G1, in the second attenuation region Z2, the light intensity decreases at a constant gradient from Q2 to zero up to the boundary between the light-blocking region A2 of the second drawing light LBD2 and the exposure region A11. Furthermore, regarding the light intensity distribution G2, in the second attenuation region Z2, the light intensity decreases at a constant gradient from Q2 to zero up to the boundary between the light-blocking region A2 of the first drawing light LBD1 and the exposure region A12.

[0092] In this third modified example, the area that produces a small amount of light ΔQ disappears, and the cumulative amount of light given to the double-exposed area AJ1 in the two main scan processes can be arbitrarily adjusted, thus avoiding overexposure.

[0093] Figure 11 The light intensity distributions G1 and G2 represent the fourth modified example. In this fourth modified example, similar to the third modified example, the light intensity is reduced in the second attenuation region Z2 of the light intensity distribution G1 up to the shading region A2 of the second depicting light LBD2. However, in the fourth modified example, the light intensity is reduced in two stages in the second attenuation region Z2. Specifically, after the light intensity decreases from Q2 to Q3 (the third light intensity) with a first gradient, the light intensity decreases from Q3 to zero with a second gradient different from the first gradient. The slope of the second gradient is less than the slope of the first gradient. Alternatively, the light intensity can be reduced in three or more stages in the second attenuation region Z2.

[0094] Furthermore, by reducing the amount of light in a gradually decreasing gradient manner, the change in light intensity in the double-exposure region AJ1 becomes smoother. This reduces the occurrence of uneven exposure or exposure streaks in the double-exposure region AJ1.

[0095] Figure 12 This represents the cumulative light intensity of the light intensity distributions G1 and G2 in the first modified example. For example... Figure 12As shown, the cumulative light amount imparted to the double-exposure region AJ1 by the first main scan process and the second main scan process is less than the light amount (Q1) imparted to the single-exposure region AS1 by the first main scan process. However, the cumulative light amount imparted to the double-exposure region AJ1 does not necessarily have to be less than the light amount (Q1) imparted to the single-exposure region AS1 by the first main scan process.

[0096] Depending on the type of photosensitive material, if the photosensitivity of the photosensitive material in a single-exposure region AS1, which is given light intensity Q1 in one main scan, is compared with that in a double-exposure region AJ1, which is given light intensity Q1 in two main scans, it can be found that the photosensitivity in the double-exposure region AJ1 is more readily achieved despite being given the same light intensity Q1. Therefore, depending on the type of photosensitive material, if the cumulative light intensity given to the double-exposure region AJ1 is the same as that given to the single-exposure region AS1, overexposure may sometimes occur in the double-exposure region AJ1. In this case, by means of... Figure 12 Setting the light distribution in that way can reduce overexposure in the double-exposure area AJ1. As a result, it can reduce the occurrence of poor exposure in the double-exposure area AJ1.

[0097] <2. Variations>

[0098] The embodiments have been described above, but the present invention is not limited to the above-described manner and various modifications are possible.

[0099] For example, in the above embodiment, the 0th-order diffracted light is used as the necessary light in the optical modulation element 461. However, diffracted light of ±1st order or higher may also be used as the necessary light.

[0100] In the above embodiments, the orientations (arrows Ar1, Ar3) of the first main scan process and the second main scan process are opposite to each other, but they can also be the same.

[0101] The present invention has been described in detail, but the foregoing description is exemplary in all respects and the invention is not limited thereto. Numerous variations not illustrated are to be understood as examples that can be conceived without departing from the scope of the invention. The structures described in the above embodiments and variations can be appropriately combined or omitted as long as they do not contradict each other.

[0102] Explanation of reference numerals in the attached figures

[0103] 1: Exposure device

[0104] 20: Workbench

[0105] 40: Exposure Department

[0106] 70: Control Department

[0107] 461: Optical modulation element

[0108] 465: Light-shielding components

[0109] A11: Exposure Area

[0110] A2: Shaded area

[0111] A3: Adjacent Areas

[0112] AJ1: Double Exposure Zone

[0113] AS1: Single exposure area

[0114] D1: Main scanning direction

[0115] D2: Sub-scanning direction

[0116] ED1: Exposure Data

[0117] ED2: Corrected exposure data

[0118] G1, G2: Light distribution

[0119] LBD1: First Depicting Light

[0120] LBD2: Second Depicting Light

[0121] W: substrate

[0122] Z1: First Attenuation Region

[0123] Z2: Second attenuation region.

Claims

1. An exposure apparatus for directly drawing a pattern on a substrate by irradiating it with drawing light. Its features are, The exposure apparatus has: The worktable holds the substrate. The exposure section illuminates the substrate with drawing light; A moving mechanism that moves the stage relative to the exposure unit in a main scanning direction and a sub-scanning direction orthogonal to the main scanning direction; and The control unit controls the exposure unit and the moving mechanism. The exposure unit includes: light source; as well as The light modulation element modulates light emitted from the light source into multiple gray levels based on instructions from the control unit. The control unit performs the main scanning process in which the exposure unit irradiates the substrate with the drawing light along the main scanning direction; And the sub-scanning process in which the exposure section moves relative to the substrate in the sub-scanning direction. The control unit controls the light modulation element to form a double-exposure region in the sub-scanning direction, where a portion of the area irradiated by the first drawing light in the first main scan process and a portion of the area irradiated by the second drawing light in the second main scan process overlap. The amount of light from the first drawing light in the sub-scanning direction is distributed in the double exposure area, including a first attenuation region where the amount of light decreases from the first amount to the second amount, and a second attenuation region where the amount of light decreases from the second amount toward zero with a gradient different from that of the first attenuation region.

2. The exposure apparatus according to claim 1, characterized in that, The exposure unit further includes a light-shielding component that blocks the light so that the light emitted from the light source does not incident on a portion of the light modulation element, thereby forming a light-shielding area at the end of the depicting light. The control unit controls the light modulation element such that in an adjacent region of the first drawing light that is adjacent to the light-blocking region of the second drawing light, the amount of light is reduced from the first amount of light to the second amount of light.

3. The exposure apparatus according to claim 1 or 2, characterized in that, The control unit corrects the light intensity in the double-exposure region based on the exposure data indicating the amount of light that should illuminate the substrate, thereby generating corrected exposure data. The control unit controls the light modulation element based on the corrected exposure data.

4. The exposure apparatus according to any one of claims 1 to 3, characterized in that, The light intensity distribution of the first depicting light includes a region between the first attenuation region and the second attenuation region where the light intensity is maintained at the second light intensity.

5. The exposure apparatus according to any one of claims 1 to 4, characterized in that, In the light intensity distribution of the first depicted light, the first attenuation region and the second attenuation region are continuous.

6. The exposure apparatus according to claim 2, characterized in that, The amount of light from the first drawing light is distributed in the second attenuation region until the light-blocking region of the second drawing light is reduced.

7. The exposure apparatus according to claim 6, characterized in that, The amount of light from the first drawing light decreases in multiple stages in the second attenuation region until the light-blocking region of the second drawing light.

8. The exposure apparatus according to any one of claims 1 to 7, characterized in that, The cumulative amount of light irradiated onto the double-exposure area by the first main scan process and the second main scan process is less than the amount of light irradiated onto the single-exposure area by the first main scan process.

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