Exposure equipment

Abstract

This technology provides a way to reduce excessive exposure when forming a double-exposure region. [Solution] The control unit 70 controls the optical modulation element 461 to form a double exposure region AJ1 in which a part of the region irradiated by the first drawing light LBD1 in the first main scanning process and a part of the region irradiated by the second drawing light LBD2 in the second main scanning process overlap in the sub-scanning direction D2. The light intensity distribution G1 of the first drawing light LBD1 in the sub-scanning direction D2 includes a first attenuation zone Z1 in the double exposure region AJ1 in which the light intensity decreases from the first light intensity Q1 to the second light intensity Q2, and a second attenuation zone Z2 in which the light intensity decreases from the second light intensity Q2 toward zero with a different gradient than the first attenuation zone Z1.

Description

TECHNICAL FIELD

[0001] The subject matter disclosed in the present specification relates to an exposure apparatus.

BACKGROUND ART

[0002] Conventionally, in order to form patterns such as wiring patterns on various substrates such as semiconductor substrates and printed circuit boards, exposure apparatuses that directly draw patterns on a layer of photosensitive material formed on the surface of the substrate have been used. This exposure apparatus modulates light emitted from a light source in accordance with exposure data representing a pattern to be drawn to generate drawing light. The exposure apparatus then irradiates the substrate held on a stage with the drawing light, thereby drawing the pattern on the substrate.

[0003] Light modulation elements that modulate a light beam include diffraction-type elements and reflection-type elements. As diffraction-type light modulation elements, for example, GLV (Grating Light Valve: a registered trademark of Silicon Light Machines, Inc. of San Jose, California, U.S.A.) and PLV (Planar Light Valve) are known. As a reflection-type light modulation element, for example, a DMD (Digital Micromirror Device) is known.

[0004] In Patent Document 1, main scanning and sub-scanning are alternately repeated. In main scanning, the drawing light is irradiated onto the substrate along the main scanning direction, and in sub-scanning, the substrate is moved in the sub-scanning direction perpendicular to the main scanning direction. Through this process, a plurality of irradiation regions are formed over the entire surface of the substrate. The irradiation regions form a connection region (double exposure region) that overlaps each other in the sub-scanning direction. The light modulation element is controlled such that the light amount of this connection region reaches the target light amount through two exposures.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0005]

PATENT DOCUMENT 1

SUMMARY OF THE INVENTION

[0006] During the main scan, the optical modulator is controlled to be off so that the light intensity is zero outside the double exposure region. However, even when the optical modulator is controlled to be off, the light intensity does not necessarily become zero, and there is a risk of slight light leakage. As a result, excessive exposure may occur in or around the double exposure region, exceeding the acceptable range, which could lead to exposure defects such as residue defects (defects where unwanted resist remains on the substrate after pattern formation) and line width defects (defects where the line width of the designed pattern differs from the actual line width). In addition, a light-shielding member may be provided on the optical modulator to prevent such minute light leakage. However, if the position of the light-shielding member is not adjusted sufficiently, there is a risk of exposure defects due to excessive exposure.

[0007] The object of the present invention is to provide a technique that can reduce excessive exposure when forming a double exposure region. [Means for solving the problem]

[0008] The first embodiment is an exposure apparatus for directly drawing a pattern on a substrate by irradiating the substrate with drawing light, comprising: a stage for holding the substrate; an exposure unit for irradiating the substrate with drawing light; a moving mechanism for moving 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 for controlling the exposure unit and the moving mechanism. The exposure unit includes a light source and a light modulation element that modulates the light emitted from the light source in multiple tones based on a command 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 controls the light modulation element to form a double exposure region in which a part of the region irradiated with a first drawing light in the first main scanning process and a part of the region irradiated with a second drawing light in the second main scanning process overlap in the sub-scanning direction. The light intensity distribution of the first drawing light in the sub-scanning direction includes, in the double exposure region, a first attenuation zone in which the light intensity decreases from a first to a second, and a second attenuation zone in which the light intensity decreases from the second towards zero with a different gradient than that of the first attenuation zone.

[0009] A second embodiment is an exposure apparatus according to the first embodiment, wherein the exposure unit further includes a light-shielding member that forms a light-shielding region at the end of the drawing light by shielding the light emitted from the light source so that the light does not enter a part of the light-modulating element. The control unit controls the light-modulating element such that, in an adjacent region of the first drawing light adjacent to the light-shielding region in the second drawing light, the amount of light decreases from the first amount of light to the second amount of light.

[0010] A third embodiment is an exposure apparatus according to the first or second embodiment, wherein the control unit generates corrected exposure data by correcting the amount of light in the double exposure region with respect to the exposure data indicating the amount of light to be irradiated onto the substrate. The control unit controls the light modulation element based on the corrected exposure data.

[0011] The fourth embodiment is an exposure apparatus according to any of the first to third embodiments, wherein the light intensity distribution of the first drawing light includes a region between the first attenuation zone and the second attenuation zone in which the light intensity is maintained at the second light intensity.

[0012] The fifth embodiment is an exposure apparatus according to any of the first to third embodiments, wherein the first attenuation zone and the second attenuation zone are continuous in the light intensity distribution of the first drawing light.

[0013] The sixth embodiment is an exposure apparatus according to the second embodiment, wherein the light intensity distribution of the first drawing light is reduced in the second attenuation zone to the light-shielding region of the second drawing light.

[0014] The seventh embodiment is an exposure apparatus according to the sixth embodiment, wherein the light intensity of the first drawing light is reduced in multiple steps in the second attenuation zone to the light-shielding region of the second drawing light.

[0015] The eighth embodiment is an exposure apparatus according to any of the first to seventh embodiments, wherein the integrated amount of light irradiated onto the double exposure region by the first main scanning process and the second main scanning process is smaller than the amount of light irradiated onto the single exposure region by the first main scanning process. [Effects of the Invention]

[0016] According to the first to eighth embodiments, by providing a first attenuation zone, excessive exposure due to light leakage can be reduced. This reduces the occurrence of residual defects or line width defects in the double exposure region.

[0017] According to the exposure apparatus of the second embodiment, even when light leakage occurs in adjacent areas due to inability to block light with the light-shielding member, overexposure can be reduced by providing a first attenuation zone.

[0018] According to the exposure apparatus of the third embodiment, the amount of light in the double exposure region can be controlled by controlling the light modulation element based on the corrected exposure data.

[0019] According to the exposure apparatus of the fourth aspect, by keeping the light quantity constant, the occurrence of exposure defects due to light quantity variation can be suppressed.

[0020] According to the exposure apparatus of the fifth aspect, by continuously reducing the light quantity, the occurrence of exposure defects due to light quantity variation can be reduced.

[0021] According to the exposure apparatus of the sixth aspect, the light modulation element is controlled so that the light quantity decreases to the light shielding member. Therefore, even when the light shielding member is displaced, the integrated light quantity applied to the double exposure region can be arbitrarily adjusted. As a result, overexposure in the double exposure region can be avoided.

[0022] According to the exposure apparatus of the eighth aspect, by reducing the light quantity in the double exposure region, overexposure in the double exposure region can be reduced. Accordingly, the occurrence of exposure defects in the double exposure region can be avoided. [Brief Description of the Drawings]

[0023] [Figure 1] It is a schematic perspective view of the exposure apparatus according to the embodiment. [Figure 2] It is a diagram showing a schematic configuration of an exposure unit. [Figure 3] It is a cross-sectional view schematically showing a schematic configuration of a light modulation element of a spatial light modulator. [Figure 4A] It is a top view showing the spatial light modulator. [Figure 4B] It is a front view showing the spatial light modulator. [Figure 5] It is a control block diagram of the exposure apparatus. [Figure 6] It is a diagram conceptually showing the top surface of a substrate W on which exposure processing is performed. [Figure 7A] It is a diagram showing light quantity distributions corresponding to the first drawing light and the second drawing light. [Figure 7B] It is a diagram showing a light quantity distribution in a case where overexposure occurs. [Figure 8] It is a diagram showing a light quantity distribution according to a first correction example. [Figure 9]This figure shows the light intensity distribution related to the second correction example. [Figure 10] This figure shows the light intensity distribution related to the third correction example. [Figure 11] This figure shows the light intensity distribution related to the fourth correction example. [Figure 12] This figure shows the integrated light quantity of the light quantity distribution in the first correction example. [Modes for carrying out the invention]

[0024] Embodiments of the present invention will be described below with reference to the attached drawings. Note that in the drawings, the dimensions and number of parts may be exaggerated or simplified for ease of understanding.

[0025] <1. Embodiment> Figure 1 is a schematic perspective view of an exposure apparatus 1 according to an embodiment. The exposure apparatus 1 is a device that directly draws a pattern on the upper surface of a substrate W on which a layer of photosensitive material (photosensitive layer) such as a resist film is formed by irradiating the upper surface of the substrate W with drawing light. 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 used in a liquid crystal display device or a plasma display device, or a substrate for an optical disc.

[0026] The exposure apparatus 1 comprises a base 10, a gantry 15, a stage 20, a stage moving mechanism 30, an exposure unit 40, and a control unit 70.

[0027] The base 10 is a support base that supports the gantry 15, stage 20, and stage movement 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 longer side of the base 10 will be referred to as the main scanning direction D1, and the direction along the shorter 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.

[0028] The gantry 15 is fixed to the upper surface of the base 10. The gantry 15 has a pair of legs 151 and a bridging portion 152. The pair of legs 151 are spaced apart in the sub-scanning direction. Each leg 151 extends upward from the upper surface of the base 10. The bridging portion 152 connects the upper ends of the legs 151 in the sub-scanning direction D2. A through-hole 18 is formed between the upper surface of the base 10 and the gantry 15, through which the substrate W can pass in the main scanning direction D1.

[0029] Stage 20 holds the substrate W horizontally. 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 shape. In a top view, the shape of the first stage 21 is rectangular, smaller than the base 10. The first stage 21 is positioned above the base 10 in a substantially horizontal position. The second stage 23 is movable along the sub-scanning direction D2. The second stage 23 has a flat shape. In a top view, the shape of the second stage 23 is rectangular, smaller than the first stage 21. The second stage 23 is positioned above the first stage 21 in a substantially horizontal position.

[0030] The stage moving mechanism 30 is a mechanism for moving the stage 20. The stage moving mechanism 30 includes a first moving mechanism 31 and a second moving mechanism 33. The first moving mechanism 31 is a mechanism for moving the first stage 21 in the main scanning direction D1 relative to the base 10 and the gantry 15. The first moving mechanism 31 is a linear motor mechanism having a pair of guide rails and a linear motor. The pair of guide rails are rails for guiding the first stage 21 in the main scanning direction D1. The pair of guide rails are provided on the upper surface of the base 10 at intervals in the sub-scanning direction D2 and extend linearly along the main scanning direction D1. The linear motor has a stator provided on the upper surface of the base 10 and a mover fixed to the lower surface of the first stage 21. When a control signal is supplied to the linear motor from the control unit 70, the mover moves along the stator in the main scanning direction D1 due to the magnetic attractive and repulsive forces generated between the stator and the mover. As a result, the first stage 21 moves relative to the base 10 in the main scanning direction D1. Note that the drive source for the first movement mechanism 31 is not limited to a linear motor. The first movement mechanism 31 may be, for example, a mechanism that converts the rotational motion of a servo motor into linear motion using a ball screw.

[0031] The second moving mechanism 33 is a mechanism for moving the second stage 23 in the sub-scanning direction D2 relative to the first stage 21. 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 arranged on the upper surface of the first stage 21 at intervals in the Y-axis direction. Each guide rail extends linearly along the sub-scanning direction D2. The pair of guide rails are rails for guiding the second stage 23 in the sub-scanning direction D2. The linear motor includes, for example, a stator provided on the upper surface of the first stage 21 and a mover fixed to the lower surface of the second stage 23. However, the second moving mechanism 33 is not limited to a linear motor mechanism, and may be, for example, a ball screw mechanism.

[0032] The substrate W is supported on the upper surface of the second stage 23 in a substantially horizontal position. The second stage 23 may have chuck pins for fixing the substrate W and a plurality of suction holes for adsorbing the substrate W. In this case, the suction holes are connected via a flow path to a negative pressure source that generates a low pressure lower than atmospheric pressure, such as a suction pump. 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 operating the first moving mechanism 31 and the second moving mechanism 33.

[0033] The exposure unit 40 is a unit that exposes the substrate W held on the second stage 23. As shown in Figure 1, the exposure unit 40 comprises a plurality (in this case, four) of 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 gantry 15. The plurality of exposure heads 41 are arranged at equal intervals along the sub-scanning direction D2.

[0034] Figure 2 shows a schematic configuration of the exposure unit 40. The laser oscillator 45 is a light source that emits laser light LB for drawing. The laser light LB emitted from the laser oscillator 45 is guided to the exposure head 41 via the illumination optical system 43. Note that instead of the laser oscillator 45, an LED (Light Emitting Diode) or a mercury lamp can also be used as the light source. The illumination optical system 43 includes a collimator lens that converts the laser light LB from the laser oscillator 45 into parallel light, and a cylindrical lens that converts it into linear light.

[0035] As shown in Figure 2, the exposure head 41 includes a spatial light modulator 46 and a projection optical system 47. The spatial light modulator 46 spatially modulates the laser light LB derived from the laser oscillator 45 on a channel-by-channel basis, causing necessary light (zero-order diffracted light) that contributes to pattern drawing and unwanted light (±1 or higher-order diffracted light (scattered light)) that does not contribute to pattern drawing to be reflected in different directions. In other words, the spatial light modulator 46 spatially modulates the laser light LB to form pattern light corresponding to the pattern to be drawn on the substrate W. The projection optical system 47 projects the formed pattern light toward the exposure position Pe on the substrate W, which is moving directly below the exposure head 41. In this way, by exposing the substrate W with pattern light, a pattern is directly drawn on the exposure position Pe on the upper surface of the substrate W. Spatial modulation of the laser light LB means changing the light intensity distribution of the laser light LB. In this embodiment, a GLV can be used as the exposure head 41. However, other diffracting type optical modulators such as a PLV may be used for the exposure head 41.

[0036] Figure 3 is a schematic cross-sectional view showing the general configuration of the optical modulation element 461 of the spatial light modulator 46. In Figure 3, three different states of the optical modulation element 461 are shown on the left, center, and right. The optical modulation element 461 has a bottom electrode 81, a plurality of fixed ribbons 82, and a plurality of movable ribbons 83. The bottom electrode 81 has, for example, a flat plate shape. The plurality of fixed ribbons 82 and the plurality of movable ribbons 83 each extend in the longitudinal direction.

[0037] In Figure 3, the xyz orthogonal coordinate axes are defined to explain the positional relationships of the various parts of the optical modulation element 461. Here, the direction in which the multiple fixed ribbons 82 and multiple movable ribbons 83 are arranged is defined as the x-direction, and the longitudinal direction of each fixed ribbon 82 and each movable ribbon 83 is defined as the y-direction. The direction perpendicular to the surface of the fixed ribbons 82 and each movable ribbon 83 is defined as the z-direction. Each fixed ribbon 82 and each movable ribbon 83 are on the same side in the z-direction and are positioned above the bottom electrode 81.

[0038] The x-direction, which is the arrangement direction of the multiple fixed ribbons 82 and the multiple movable ribbons 83, is approximately parallel to the sub-scanning direction D2. The fixed ribbons 82 and the movable ribbons 83 are arranged alternately along the x-direction parallel to the sub-scanning direction D2 in the horizontal direction. That is, the optical modulation elements 461 are arranged along the arrangement direction parallel to the sub-scanning direction D2 in the horizontal direction.

[0039] The laser light LB emitted from the laser oscillator 45 is incident on the +z side surface of each fixed ribbon 82 and each movable ribbon 83 from one side in the z direction via a mirror or the like in the illumination optical system 43. For ease of explanation, the laser light LB incident on the fixed ribbon 82 and the movable ribbon 83 will also be referred to as "incident light Li" below. The fixed ribbon 82 has a fixed reflective surface 82S, and the movable ribbon 83 has a movable reflective surface 83S. The fixed reflective surface 82S and the movable reflective surface 83S are each finished to be planar. The multiple fixed reflective surfaces 82S and the multiple movable reflective surfaces 83S form the focusing surface 461S of the optical modulation element 461.

[0040] The fixed reflective surface 82S is fixed at a predetermined distance from the bottom electrode 81. The movable reflective surface 83S is provided to move toward and away from the bottom electrode 81 in accordance with the applied voltage (driving voltage). That is, the movable reflective surface 83S is movable in the z direction perpendicular to the fixed reflective surface 82S.

[0041] The displacement of the movable reflective surface 83S is adjusted according to the magnitude of the potential difference generated between the movable ribbon 83 and the bottom electrode 81 by the driving voltage. For example, as shown on the left side of Figure 3, when the height difference h between the fixed reflective surface 82S and the movable reflective surface 83S is zero, the light reflected by the fixed reflective surface 82S and the light reflected by the movable reflective surface 83S are in phase, and therefore these lights are reflected from the optical modulation element 461 as zero-order diffracted light Lr.

[0042] More specifically, when the wavelength of the incident light Li is λ, if the optical path difference (=2h) between the light reflected by the fixed reflective surface 82S and the light reflected by the movable reflective surface 83S is an integer multiple of the wavelength λ (=n × λ (where n is a non-negative integer)), then the light reflected by the fixed reflective surface 82S and the light reflected by the movable reflective surface 83S are in phase. In this case, zero-order diffracted light Lr is emitted from the optical modulation element 461.

[0043] Furthermore, as shown in the center of Figure 3, when the optical path difference (=2h) between the light reflected by the fixed reflective surface 82S and the light reflected by the movable reflective surface 83S is an odd multiple of half a wavelength λ / 2, the light reflected by the fixed reflective surface 82S and the light reflected by the movable reflective surface 83S are out of phase and cancel each other out. For this reason, no reflected light in the vertical direction is emitted from the optical modulation element 461, and only light emitted in an oblique direction, i.e., diffracted light (scattered light Ld) of order ±1 or higher is emitted.

[0044] Furthermore, as shown on the right side of Figure 3, if the optical path difference (=2h) between the light reflected by the fixed reflective surface 82S and the light reflected by the movable reflective surface 83S is not an integer multiple of the wavelength λ and is not an odd multiple of half-wavelength λ / 2, then a portion of the incident light Li is emitted as zero-order diffracted light Lr, and the remainder is emitted obliquely as ±1st order or higher diffracted light (scattered light Ld). In other words, depending on the magnitude of the height difference h, zero-order diffracted light Lr with a weaker intensity than the incident light Li is emitted from the optical modulation element 461. Thus, in the optical modulation element 461, the intensity of the zero-order diffracted light Lr (or the intensity of the scattered light Ld) can be adjusted by changing the driving voltage. As a result, the optical modulation element 461 is capable of modulating the laser light LB emitted from the laser oscillator 45, which is the light source, in multiple gradations.

[0045] The projection optical system 47 reduces the laser light LB (zero-order diffracted light Lr) modulated by the optical modulation element 461 of the spatial light modulator 46 and emits it toward the substrate W. As shown in Figure 2, the projection optical system 47 reduces the laser light LB (zero-order diffracted light Lr) modulated by the spatial light modulator 46 and images it toward the upper surface of the substrate W on which the resist film is formed. In other words, the exposure unit 40 irradiates the substrate W with the laser light LB modulated by the spatial light modulator 46 via the projection optical system 47. In other words, the exposure apparatus 1 performs drawing by directly irradiating the substrate W with the zero-order diffracted light Lr emitted from the spatial light modulator 46 via the projection optical system 47. Note that diffracted light (scattered light Ld) of order ±1 or higher emitted from the optical modulation element 461 is blocked by the aperture 47a of the projection optical system 47. That is, diffracted light (scattered light Ld) of order ±1 or higher is not emitted from the projection optical system 47 and does not contribute to the drawing of the pattern.

[0046] Therefore, in the following explanation, the state shown on the left or right side of Figure 3 will be referred to as the "on state," and the state shown in the center of Figure 4 will be referred to as the "off state." The "on state" is the state in which laser light LB (zero-order diffracted light Lr) is irradiated from the spatial light modulator 46 toward the substrate W, and a pattern is drawn on the upper surface of the substrate W. However, in the state shown on the right side of Figure 3, the intensity of the laser light LB (zero-order diffracted light Lr) irradiated from the spatial light modulator 46 toward the substrate W is smaller than in the state shown on the left side of Figure 3. The "off state" is the state in which laser light LB (zero-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 controlling the spatial light modulator 46 and adjusting the magnitude of the drive voltage applied to the movable ribbon 83.

[0047] The smallest unit that controls the "on state" and "off state" is called channel C. Channel C consists of a set of fixed ribbons 82 and movable ribbons 83. The drive voltage can be set individually for each movable ribbon 83 in the optical modulation element 461. Therefore, each channel C can be controlled between the "on state" and the "off state". Channel C may consist of multiple sets of fixed ribbons 82 and movable ribbons 83.

[0048] Figure 4A is a top view showing the spatial light modulator 46. Figure 4B is a front view showing the spatial light modulator 46. As shown in Figures 4A and 4B, the spatial light modulator 46 comprises a light modulation element 461, a single slide glass 463, and two light-shielding members 465. The slide glass 463 is positioned away from the light modulation element 461 on the +z side. The slide glass 463 is transparent. The slide glass 463 transmits the laser light LB incident on the light modulation element 461 and the laser light LB reflected by the light modulation element 461 (zero-order diffracted light Lr and scattered light Ld).

[0049] The light-shielding members 465 are members that suppress the transmission of light and are made of, for example, metal. Each of the light-shielding members 465 is positioned on the +z side surface of the slide glass 463. Of the two light-shielding members 465, one is positioned at the +x side end of the slide glass 463 and the other is positioned at the -x side end of the slide glass 463.

[0050] The light-shielding member 465 shields the laser light LB emitted from the laser oscillator 45 (light source) so that it does not enter a portion of the optical modulation element 461 in the spatial light modulator 46. More specifically, it shields the laser light LB that enters the multiple channels C located at the ends of the optical modulation element 461. As a result, the light-shielding member 465 forms a light-shielding region at the ends of the drawing light LBD irradiated onto the substrate W. The multiple channels C covered by the light-shielding member 465 become channels (dummy ribbons) that do not contribute to the formation of the drawing light. The positional relationship between the light-shielding member 465 and the optical modulation element 461 is adjusted, for example, when the exposure apparatus 1 is started up.

[0051] Figure 5 is a control block diagram of the exposure apparatus 1. The control unit 70 is a device that controls the operation of each part of the exposure apparatus 1. The control unit 70 is a computer equipped with 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 by bus wiring (not shown).

[0052] The processor 71 includes a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The processor 71 may also include a general-purpose arithmetic unit, a dedicated arithmetic unit, or a GPU (Graphics Processing Unit). A dedicated arithmetic unit includes, for example, an ASIC (Application Specific Integrated Circuit).

[0053] Memory 73 includes main memory. Main memory includes, for example, semiconductor memory such as RAM (Random-Access Memory). Memory 73 may also include non-volatile memory such as ROM (Read-Only Memory) for storing programs and data. Auxiliary storage 75 includes a solid-state drive (SSD) or a hard disk drive (HDD). Auxiliary storage 75 may also include removable media.

[0054] The auxiliary storage device 75 stores the 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.

[0055] 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 to the control unit 70 in response to the operator's actions. The input unit 77 includes a keyboard 771 and a mouse 773. The input unit 77 may include a reader for reading data from removable media.

[0056] The output unit 78 includes a display 781 that displays various information. The display is, for example, a liquid crystal display or an organic EL (electroluminescent) display. The input unit 77 may include a touch panel sensor superimposed on the display surface of the display 781. The output unit 78 may include a speaker, a printer, or a lamp.

[0057] The auxiliary storage device 75 stores the exposure data ED1. The exposure data ED1 represents the shape of the pattern to be drawn and specifies the amount of exposure required to form that pattern. The exposure data ED1 is obtained by rasterizing vector data generated using, for example, CAD (Computer Aided Design).

[0058] The control unit 70 is electrically connected to the first movement mechanism 31 and the second movement mechanism 33 of the stage movement mechanism 30, as well as the laser oscillator 45 and optical modulation element 461 of the 60. The control unit 70 controls the first movement mechanism 31, the second movement mechanism 33, the laser oscillator 45, and the optical modulation element 461 based on exposure data ED1 according to the computer program PG1. This performs the exposure process of the substrate W in the exposure apparatus 1.

[0059] Figure 6 is a conceptual diagram showing the upper surface of the substrate W that has been subjected to exposure processing. As shown in Figure 6, the control unit 70 alternately performs a main scanning process in which the exposure unit 40 irradiates the drawing light LBD along the main scanning direction D1, and a sub-scanning process in which the exposure unit 40 moves relative to the substrate W in the sub-scanning direction D2, while the substrate W is held on the stage 20.

[0060] During the main scanning process, the control unit 70 operates the first moving mechanism 31 to move the substrate W in the main scanning direction D1 relative to the exposure head 41. As a result, the substrate W moves in the main scanning direction D1 relative to the exposure head 41. Viewed from the stage 20, as shown by arrow Ar1 in Figure 6, the exposure head 41 traverses the substrate W along the main scanning direction D1. While the exposure head 41 traverses the substrate W, the exposure head 41 irradiates the substrate W with spatially modulated drawing light LBD based on the exposure data ED1. The spatial light modulator 46 modulates the drawing light LBD irradiated onto the substrate W based on a command (control signal) from the control unit 70. This main scanning process forms a strip-shaped exposure region A11 on the upper surface of the substrate W, extending along the main scanning direction D1.

[0061] In the sub-scanning process, the control unit 70 operates the second moving mechanism 33 to move the substrate W in the sub-scanning direction D2 relative to the exposure head 41 by a predetermined distance. As a result, the substrate W moves a predetermined distance along the sub-scanning direction D2 relative to the exposure head 41. From the perspective of the substrate W, as shown by arrow Ar2 in Figure 6, the exposure head 41 moves a predetermined distance along the sub-scanning direction D2. The predetermined distance is smaller than the width of the exposure area A11 in the sub-scanning direction D2.

[0062] Once the sub-scanning process is complete, the control unit 70 performs the main scanning process again, as indicated by arrow Ar3 in Figure 6. As a result, a strip-shaped exposure region A12 is formed along the main scanning direction D1. In this way, the control unit 70 draws a pattern on the exposure target region of the substrate W by alternately performing the main scanning process and the sub-scanning process.

[0063] Hereinafter, the main scanning process that forms the exposure region A11 will be referred to as the "first main scanning process." The drawing light LBD irradiated during the first main scanning process will be referred to as the "first drawing light LBD1." Hereinafter, the main scanning process that forms the exposure region A12 will be referred to as the "second main scanning process." The drawing light LBD irradiated during the second main scanning process will be referred to as the "second drawing light LBD2."

[0064] The control unit 70 forms a single-exposure region AS1 and a double-exposure region AJ1 by performing two main scanning processes. The single-exposure region AS1 is a region that is exposed only once by either the first drawing light LBD1 or the second drawing light LBD2. The double-exposure region AJ1 is a region that is exposed twice by both the first drawing light LBD1 and the second drawing light LBD2. The double-exposure region AJ1 is a region where a part of the exposure region A11 and a part of the exposure region A12 overlap in the sub-scanning direction D2. By providing the double-exposure region AJ1 at the boundary between the exposure regions A11 and A12 in this way, the occurrence of uneven exposure and exposure streaks at the boundary can be suppressed.

[0065] Figure 7A shows the light intensity distributions G1 and G2 corresponding to the first drawing light LBD1 and the second drawing light LBD2. In Figure 7A, the horizontal axis represents the position on the substrate W in the sub-scanning direction D2, and the vertical axis represents the light intensity.

[0066] As shown in Figure 7A, light-shielding members 465 are placed at both ends of the optical modulation element 461. As a result, light-shielding regions A2, where the light intensity is completely zero, are formed at both ends of the drawing light LBD. When the light-shielding members 465 are installed as designed, as shown in Figure 7A, the light intensity of the drawing light LBD in the double exposure region AJ1 is reduced at a constant gradient from Q1 (first light intensity) to zero in the light-shielding region A2. As a result, by performing two main scanning processes, the double exposure region AJ1 is given the same amount of light as the single exposure region AS1. The channels C involved in this double exposure region AJ1 are composed of, for example, 40 (40 channels).

[0067] Here, channel C, covered by the light-shielding member 465, is normally controlled to the off state. However, even if channel C is controlled to the off state, it is difficult to completely reduce the amount of light to zero. If the light-shielding member 465 is installed in a misaligned position, light leaking from the off-state channel C may irradiate the substrate W, potentially causing overexposure. This overexposure will be explained in detail with reference to Figure 7B.

[0068] Figure 7B shows the light intensity distributions G1 and G2 when overexposure occurs. As shown in Figure 7B, due to the misalignment of the light-shielding member 465, a small amount of light ΔQ is generated in the adjacent region A3 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 of the second drawing light LBD2. In this case, each adjacent region A3 is irradiated with an amount of light Q1 + ΔQ by two main scanning processes, resulting in overexposure of ΔQ. If the overexposure exceeds the acceptable range, exposure defects such as poor residue or poor line width occur at the boundary between the exposed regions A11 and A12.

[0069] 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. The control unit 70 also controls the light modulation element 461 based on the corrected exposure data ED2 to generate corrected light intensity distributions G1 and G2 in the double exposure region AJ1. Examples of correcting light intensity distributions G1 and G2 will be described below.

[0070] Figure 8 shows the light intensity distributions G1 and G2 for the first correction example. In this first correction example, the light intensity distribution G1 includes a first attenuation zone Z1 inside the double exposure region AJ1, where the light decreases from Q1 (first light intensity) to Q2 (second light intensity), and a second attenuation zone Z2 where the light intensity decreases from Q2 to zero (off state). The light intensity distribution G1 of the first correction example also includes a constant light intensity zone Z3 between the first attenuation zone Z1 and the second attenuation zone Z2, where the light intensity is maintained at Q2. The light intensity distribution G2 of the second drawing light LBD2 is similar to the light intensity distribution G1, including a first attenuation zone Z1 and a second attenuation zone Z2 inside the double exposure region AJ1, and a constant light intensity zone Z3 located between the first attenuation zone Z1 and the second attenuation zone Z2.

[0071] In this first correction example, in the double exposure region AJ1, the light intensity decreases in two stages, from Q1 to zero (off state). The gradient of the light intensity change in the second attenuation zone Z2 is different from the gradient of the light intensity change in the first attenuation zone Z1. Specifically, the gradient in the second attenuation zone Z2 is smaller than the gradient in the first attenuation zone Z1. That is, the light intensity decreases more gradually in the second attenuation zone Z2 than in the first attenuation zone Z1.

[0072] Focusing on the light intensity distribution G1 of the first drawing light LBD1, the first attenuation zone Z1 of the light intensity distribution G1 is set inside the adjacent region A3 of the second drawing light LBD2. In other words, the control unit 70 controls the optical modulation element 461 so that the light intensity of the first drawing light LBD1 decreases from Q1 to Q2 in the region that overlaps with the adjacent region A3 of the second drawing light LBD2. Furthermore, focusing on the light intensity distribution G2 of the second drawing light LBD2, the first attenuation zone Z1 of the light intensity distribution G2 is set inside the adjacent region A3 of the first drawing light LBD1. In other words, the control unit 70 controls the optical modulation element 461 so that the light intensity of the second drawing light LBD2 decreases from Q1 to Q2 in the region that overlaps with the adjacent region A3 of the first drawing light LBD1. The channel C contributing to the first attenuation zone Z1 and the amount of decrease in the first attenuation zone Z1 (=Q1-Q2) are appropriately optimized, for example, by a preliminary exposure process.

[0073] In this way, by providing the first attenuation zone Z1, overexposure due to light leakage can be reduced. As a result, exposure defects in the double exposure region AJ1 can be reduced. Furthermore, by setting the first attenuation zone Z1 to an area that overlaps with the adjacent region A3, overexposure can be suppressed even if the light-shielding member 465 is misaligned.

[0074] Double exposure regions AJ1 may be formed at both ends of exposure regions A11 and A12. In this case, as shown in Figure 8, a first attenuation zone Z1, a second attenuation zone Z2, and a constant light intensity zone Z3 are provided at both ends of light intensity distributions G1 and G2, respectively.

[0075] Figure 9 shows the light intensity distributions G1 and G2 in the second correction example. The light intensity distributions G1 and G2 in this second correction example include a first attenuation zone Z1 in which the light intensity decreases at a constant gradient from Q1 to Q2, and a second attenuation zone Z2 in which the light intensity decreases at a constant gradient from Q2 towards zero. In this second correction example, the first attenuation zone Z1 and the second attenuation zone Z2 are continuous, and there is no zone in which the light intensity is maintained at a constant level at Q2 (constant light intensity zone Z3), which is different from the first correction example.

[0076] According to this second correction example, the light intensity changes more smoothly at the boundary between the first attenuation zone Z1 and the second attenuation zone Z2 inside the double exposure region AJ1 than in the first correction example. Therefore, exposure defects such as line width fluctuations caused by changing the light intensity in two stages inside the double exposure region AJ1 can be reduced.

[0077] Figure 10 shows the light intensity distributions G1 and G2 related to the third correction example. In this third correction example, similar to the second correction example, the first attenuation zone Z1 and the second attenuation zone Z2 are consecutively located inside the double exposure region AJ1. However, in the third correction example, the light intensity is reduced at a constant gradient up to the boundary between the light-shielding region A2 and the exposure regions A11 and A12. Therefore, focusing on the light intensity distribution G1, in the second attenuation zone Z2, the light intensity decreases at a constant gradient from Q2 to zero up to the boundary between the light-shielding region A2 and the exposure region A11 of the second drawing light LBD2. Similarly, in the light intensity distribution G2, in the second attenuation zone Z2, the light intensity decreases at a constant gradient from Q2 to zero up to the boundary between the light-shielding region A2 and the exposure region A12 of the first drawing light LBD1.

[0078] In this third correction example, the region where minute light intensity ΔQ occurs is eliminated, and the integrated light intensity applied to the double-exposure region AJ1 can be arbitrarily adjusted in two main scanning processes, thus avoiding overexposure.

[0079] Figure 11 shows the light intensity distributions G1 and G2 related to the fourth correction example. In this fourth correction example, similar to the third correction example, the light intensity is reduced in the second attenuation zone Z2 of the light intensity distribution G1 up to the shading region A2 of the second drawing light LBD2. However, in the fourth correction example, the light intensity is reduced in two stages in the second attenuation zone Z2. Specifically, the light intensity decreases from Q2 to Q3 (third light intensity) with a first gradient, and then from Q3 to zero light intensity with a second gradient different from the first gradient. The second gradient has a smaller slope than the first gradient. Note that the light intensity may be reduced in three or more stages in the second attenuation zone Z2.

[0080] Furthermore, by gradually reducing the light intensity so that the gradient becomes smaller, the change in light intensity in the double exposure region AJ1 becomes more gradual. This reduces the occurrence of uneven exposure or exposure streaks in the double exposure region AJ1.

[0081] Figure 12 shows the integrated light quantities of light distributions G1 and G2 in the first correction example. As shown in Figure 12, the integrated light quantity applied to the double-exposure region AJ1 by the first and second main scanning processes is smaller than the light quantity (Q1) applied to the single-exposure region AS1 by the first main scanning process. However, it is not essential that the integrated light quantity applied to the double-exposure region AJ1 be smaller than the light quantity (Q1) applied to the single-exposure region AS1 by the first main scanning process.

[0082] Depending on the type of photosensitive material, when comparing the photosensitive reaction of the photosensitive material in a single-exposure region AS1 to which light intensity Q1 is applied in one main scan process, and in a double-exposure region AJ1 to which light intensity Q1 is applied in two main scan processes, the photosensitive reaction in the double-exposure region AJ1 may proceed more quickly, even though the same light intensity Q1 is applied. Therefore, depending on the type of photosensitive material, if the integrated light intensity applied to the double-exposure region AJ1 is the same as the light intensity applied to the single-exposure region AS1, overexposure may occur in the double-exposure region AJ1. In this case, overexposure in the double-exposure region AJ1 can be reduced by setting the light intensity distribution as shown in Figure 12. As a result, the occurrence of exposure defects in the double-exposure region AJ1 can be reduced.

[0083] <2. Variant Example> Although embodiments have been described above, the present invention is not limited to those described above, and various modifications are possible.

[0084] For example, in the above embodiment, zero-order diffracted light is used as the required light in the optical modulation element 461. However, diffracted light of order ±1 or higher may also be used as the required light.

[0085] In the above embodiment, the directions of the first and second main scanning processes (arrows Ar1, Ar3) are opposite to each other, but they may be the same direction.

[0086] Although this invention has been described in detail, the above description is illustrative in all respects, and the invention is not limited thereto. It is understood that countless variations not illustrated can be conceived without falling outside the scope of this invention. The components described in each of the above embodiments and variations can be combined or omitted as appropriate, as long as they do not contradict each other. [Explanation of Symbols]

[0087] 1: Exposure device 20: Stage 40: Exposure area 70: Control Unit 461: Optical Modulator 465: Light-shielding material A11: Exposure area A2: Shade area A3: Adjacent area AJ1: Double exposure area AS1: Single exposure area D1: Main scanning direction D2: Sub-scanning direction ED1: Exposure data ED2: Corrected exposure data G1,G2:Light amount distribution LBD1: First drawing light LBD2: Second drawing light W: Circuit board Z1: First damping zone Z2: Second damping zone

Claims

1. An exposure apparatus for directly drawing a pattern on a substrate by irradiating the substrate with drawing light, A stage for holding 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 the main scanning direction and in a sub-scanning direction perpendicular to the main scanning direction, A control unit that controls the exposure unit and the moving mechanism, Equipped with, The exposure unit is Light source and A light modulation element that modulates the light emitted from the light source in multiple shades based on a command from the control unit, Includes, 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 controls the optical modulation element to form a double exposure region in which a part of the region irradiated with the first drawing light in the first main scanning process and a part of the region irradiated with the second drawing light in the second main scanning process overlap in the sub-scanning direction. An exposure apparatus in which the light intensity distribution of the first drawing light in the sub-scanning direction includes, in the double exposure region, a first attenuation zone in which the light intensity decreases from a first light intensity to a second light intensity, and a second attenuation zone in which the light intensity decreases from the second light intensity toward zero with a different gradient than that of the first attenuation zone.

2. An exposure apparatus according to claim 1, The exposure unit is A light-shielding member that blocks the light so that the light emitted from the light source does not come into contact with a part of the light modulation element, thereby forming a light-shielding region at the edge of the drawing light. It further includes, An exposure apparatus in which the control unit controls the light modulation element such that the amount of light decreases from the first amount of light to the second amount of light in an adjacent region of the first drawing light adjacent to the light-shielding region of the second drawing light.

3. An exposure apparatus according to claim 1, The control unit generates corrected exposure data by correcting the amount of light in the double exposure region for the exposure data indicating the amount of light to be irradiated onto the substrate. The control unit controls the light modulation element based on the corrected exposure data in the exposure apparatus.

4. An exposure apparatus according to claim 1, An exposure apparatus wherein the light intensity distribution of the first drawing light includes a region between the first attenuation zone and the second attenuation zone in which the light intensity is maintained at the second light intensity.

5. An exposure apparatus according to claim 1, An exposure apparatus in which the first attenuation zone and the second attenuation zone are continuous in the light intensity distribution of the first drawing light.

6. An exposure apparatus according to claim 2, An exposure apparatus in which the light intensity distribution of the first drawing light decreases in the second attenuation zone to the light-shielding region of the second drawing light.

7. An exposure apparatus according to claim 6, An exposure apparatus wherein the light intensity of the first drawing light decreases in multiple steps in the second attenuation zone to the light-shielding region of the second drawing light.

8. An exposure apparatus according to any one of claims 1 to 7, An exposure apparatus in which the integrated amount of light irradiated onto the double exposure region by the first main scanning process and the second main scanning process is smaller than the amount of light irradiated onto the single exposure region by the first main scanning process.

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