Exposure device and exposure method

Abstract

To provide a technique capable of reducing unevenness of an exposure amount even if overlapping accuracy of a plurality of line beams formed of a plurality of light sources is low.SOLUTION: An exposure device 100 includes a stage 10, an illumination optical system 53, a spatial light modulator 41, a projection optical system 43, and a control part 90. The stage 10 holds a substrate W. The spatial light modulator 41 forms light from a plurality of light sources into a plurality of line beams, and makes the line beams overlap with a predetermined focal position. The spatial light modulator 41 subjects a synthesis line beam formed by overlapping the plurality of line beams by the illumination optical system 53 to spatial modulation. The projection optical system 43 projects the synthesis line beam subjected to the spatial modulation by the spatial light modulator onto the substrate held by the stage 10. An exposure amount adjustment part of the control part 90 adjusts an exposure amount of the substrate W by the synthesis line beam, according to a line width in a minor axis direction of the synthesis line beam.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The subject matter disclosed herein relates to an exposure apparatus and method. [Background technology]

[0002] Exposure devices that perform drawing by irradiating light are known as a method for forming patterns such as circuits on substrates such as semiconductor wafers and glass substrates. In such exposure devices, a light beam modulated based on CAD data or the like is used to scan a photosensitive material such as a resist applied to a substrate, thereby drawing a pattern directly on the photosensitive material.

[0003] Such exposure devices are equipped with optical modulation elements that perform on / off modulation of the light beam to the photosensitive material on a pixel-by-pixel basis. Reflective spatial light modulators draw patterns by switching between an on state, in which the light beam supplied from the light source is reflected and applied onto the substrate, and an off state, in which the light beam is reflected or diffused toward the outside of the substrate, on a pixel-by-pixel basis according to the drawing pattern of the drawing data.

[0004] When a laser light source (e.g., a laser diode) is used as the light source of the exposure device, an illumination optical system that mixes the light emitted from multiple laser diodes to obtain a high exposure dose, and a projection optical system that reduces and projects a pattern image generated by a spatial light modulator onto a substrate may be employed.

[0005] For example, in Patent Document 1, an illumination optical system superimposes line beams formed from light from multiple laser light sources on the focusing surface of a spatial light modulator, and a reduction projection system projects the line beam modulated by the spatial light modulator onto a substrate, thereby exposing the substrate. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2015-192080 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, when multiple line beams are superimposed as in Patent Document 1, if the superimposition accuracy is low, there is a risk of unevenness in the amount of exposure on the substrate due to unevenness in intensity, etc. If unevenness in the amount of exposure occurs, it becomes difficult to ensure uniformity in the line width of the pattern formed on the substrate after patterning. Therefore, in order to superimpose multiple line beams with high accuracy, adjustments are made to the illumination optical system.

[0008] However, in order to superimpose multiple line beams with high precision, the optical elements along the line beam's path must be adjusted to the order of several microns, which requires complicated adjustment work. In addition, the more laser light sources there are, the longer the adjustment work may take. Furthermore, if a mechanism for automatically performing the adjustment work is incorporated into the device, the device configuration becomes more complex, which may result in an increase in size and an increase in device costs.

[0009] An object of the present invention is to provide a technique capable of reducing unevenness in the amount of exposure even when the overlapping accuracy of a plurality of line beams formed from a plurality of light sources is low. [Means for solving the problem]

[0010] In order to solve the above problem, a first aspect is an exposure apparatus comprising: a stage for holding a substrate; an illumination optical system for shaping light from multiple light sources into multiple line beams and superimposing them at a predetermined focal position; a spatial light modulator for spatially modulating a composite line beam formed by superimposing the multiple line beams by the illumination optical system; a projection optical system for projecting the composite line beam spatially modulated by the spatial light modulator onto a substrate held on the stage; and an exposure amount adjustment unit for adjusting the exposure amount of the substrate by the composite line beam in accordance with the line width of the composite line beam in the short axis direction.

[0011] A second aspect is the exposure apparatus of the first aspect, further comprising an observation unit capable of measuring the line width of the combined line beam.

[0012] A third aspect is the exposure apparatus of the first or second aspect, wherein the light amount adjustment unit adjusts an exposure time for exposing the substrate for each channel of the spatial light modulator in accordance with the line width.

[0013] A fourth aspect is the exposure apparatus of the first or second aspect, wherein the light amount adjustment section adjusts the intensity of the combined beam for each channel of the spatial light modulator in accordance with the line width.

[0014] A fifth aspect is an exposure method including the steps of: holding a substrate on a stage; shaping light from multiple light sources into multiple line beams in an illumination optical system and superimposing the line beams at a predetermined focal position; spatially modulating a composite line beam formed by superimposing the multiple line beams by the illumination optical system using a spatial light modulator; projecting the composite line beam spatially modulated by the spatial light modulator onto a substrate held on the stage using a projection optical system; and adjusting the amount of exposure of the substrate by the composite line beam in accordance with the line width of the composite line beam in the major axis direction. Effect of the Invention

[0015] According to the exposure apparatus of the first to fourth aspects and the exposure method of the fifth aspect, even if the accuracy of overlapping of multiple line beams is low, the exposure amount on the substrate can be made uniform by adjusting the exposure amount according to the line width of the composite line beam.

[0016] According to the exposure apparatus of the second aspect, the line width of the combined line beam can be measured in the exposure apparatus, which makes it possible to eliminate the need to measure the line width in a separate apparatus.

[0017] According to the exposure apparatus of the third aspect, the amount of exposure light on the substrate can be made uniform.

[0018] According to the exposure apparatus of the fourth aspect, the amount of exposure light on the substrate can be made uniform. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram showing an exposure apparatus according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing an illumination optical system of the exposure apparatus shown in FIG. [Diagram 3] 2 is a cross-sectional view showing a spatial light modulator of the exposure apparatus shown in FIG. [Figure 4] FIG. 2 is a diagram showing an observation optical system of the exposure apparatus shown in FIG. [Diagram 5] 2 is a block diagram showing a control unit of the exposure apparatus shown in FIG. [Figure 6] 11 is a diagram showing a correction data generation flow executed by an exposure amount adjustment unit. [Figure 7] FIG. 2 is a schematic diagram showing a combined line beam formed on a focusing surface of a spatial light modulator. [Figure 8] FIG. 2 is a schematic diagram showing a combined line beam formed on a focusing surface of a spatial light modulator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the components described in the embodiment are merely examples, and are not intended to limit the scope of the present invention. In the drawings, the dimensions and numbers of each part may be exaggerated or simplified as necessary for ease of understanding.

[0021] <1. Embodiment> 1 is a diagram showing an exposure apparatus 100 according to an embodiment. The exposure apparatus 100 is an apparatus that draws a pattern by irradiating light onto the upper surface of a substrate W on which a layer of a photosensitive material such as a resist has been formed. 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 disk.

[0022] The exposure apparatus 100 includes a main body frame 101. The exposure apparatus 100 has a processing area 102 and a transfer area 103 inside the main body frame 101. In the processing area 102, a stage 10, a stage moving mechanism 20, and an optical unit U are arranged. In the transfer area 103, a transport device 70 that loads and unloads a substrate W is arranged. The exposure apparatus 100 also includes a control unit 90.

[0023] A cassette placement part 104 for placing a cassette C is disposed at a position adjacent to the transfer area 103. The transport device 70 takes out the unprocessed substrate W contained in the cassette C and carries it into the processing area 102, and also carries the processed substrate W out of the processing area 102 and stores it in the cassette C. The cassette C is transferred to and from the cassette placement part 104 by an external transport device (not shown). The transport device 70 carries the substrate W in and out under the control of the control unit 90.

[0024] The stage 10 has a rectangular shape when viewed from above. The stage 10 has an upper surface that holds the substrate W. The substrate W is placed in a horizontal position on the upper surface of the stage 10. A plurality of suction holes are formed in the upper surface of the stage 10. The stage 10 is capable of fixing the substrate W to the upper surface of the stage 10 by applying a negative pressure (suction pressure) to the suction holes. Note that a chuck that grips the periphery of the substrate W may be provided on the upper surface of the stage 10, and the substrate W may be fixed by the chuck.

[0025] The stage moving mechanism 20 is a mechanism that moves the stage 10 in the Y direction which is the main scanning direction, the X direction which is the sub-scanning direction, and in a rotation direction (θ-axis direction) about a rotation axis A which extends in the Z direction. The stage moving mechanism 20 has a support plate 22, a sub-scanning mechanism 23, a base plate 24, a main scanning mechanism 25, and a rotation mechanism 27.

[0026] The support plate 22 supports the stage 10 so as to be rotatable. The base plate 24 supports the support plate 22 and the sub-scanning mechanism 23. The sub-scanning mechanism 23 moves the support plate 22 and the stage 10 in the X direction relative to the base plate 24. The main scanning mechanism 25 moves the support plate 22 and the stage 10 in the Y direction together with the base plate 24. The rotation mechanism 27 rotates the stage 10 around a rotation axis A relative to the support plate 22. The sub-scanning mechanism 23, the main scanning mechanism 25, and the rotation mechanism 27 are each composed of a ball screw mechanism having a rotary motor and a ball screw, or a linear motor mechanism. The operations of the sub-scanning mechanism 23, the main scanning mechanism 25, and the rotation mechanism 27 are controlled by a control unit 90.

[0027] The optical unit U has a plurality of (e.g., five) exposure heads 4 arranged in the X direction. The exposure heads 4 include a spatial light modulator 41 and a projection optical system 43. The spatial light modulator 41 spatially modulates a laser beam based on drawing data corresponding to a drawing pattern. The projection optical system 43 reduces the laser beam (a composite line beam LBs, described later) spatially modulated by the spatial light modulator 41, and emits it toward the stage 10.

[0028] The optical unit U includes a plurality of (e.g., five) light irradiation units 5. The optical unit U includes one light irradiation unit 5 for one exposure head 4. Since the plurality of light irradiation units 5 all have the same configuration, one light irradiation unit 5 will be described below.

[0029] The light irradiation unit 5 has a laser driving unit 51 and an illumination optical system 53. The laser driving unit 51 is a device that drives a light source of the illumination optical system 53. The illumination optical system 53 is a device that projects laser light (a composite line beam LBs described later) onto the spatial light modulator 41 of the exposure head 4.

[0030] Fig. 2 is a diagram showing the illumination optical system 53 of the exposure apparatus 100 shown in Fig. 1. The illumination optical system 53 has a plurality of light source units 61, a rod integrator 63, and a condenser lens unit 65. Each light source unit 61 has a laser light source 611 such as a laser diode, and a collimator lens 613.

[0031] The laser light emitted from each laser light source 611 is converted into parallel light by a collimator lens 613, and then guided to a rod integrator 63 via an optical fiber (not shown). The rod integrator 63 distributes the laser light emitted from the optical fiber uniformly. The laser light passing through the rod integrator 63 heads toward a condenser lens unit 65. The condenser lens unit 65 is composed of a cylindrical lens or the like, and focuses the light beam emitted from the rod integrator 63 at a focal position while shaping the beam into a line beam. The focal position of the condenser lens unit 65 is adjusted to the focusing surface 41S of the spatial light modulator 41 in the exposure head 4.

[0032] As shown in FIG. 2, a plurality of line beams LB are superimposed on the light collecting surface 41S of the spatial light modulator 41. For convenience of explanation, only three line beams LB1 to LB3 are shown in FIG. 2, but in reality, the same number of line beams LB as the number of laser light sources 611 (for example, five) are irradiated onto the spatial light modulator 41. In the following explanation, a beam formed by superimposing a plurality of line beams LB is referred to as a "synthetic line beam LBs". The spatial light modulator 41 spatially modulates the superimposed plurality of line beams LB, i.e., the synthetic line beam LBs. Note that spatially modulating light means changing the spatial distribution (amplitude, phase, polarization, etc.) of light.

[0033] FIG. 3 is a cross-sectional view showing the spatial light modulator 41 of the exposure apparatus 100 shown in FIG. 1. The spatial light modulator 41 is a GLV (Grating Light Valve, a registered trademark of Silicon Light Machines, Inc., USA), which is a diffractive modulation element. The spatial light modulator 41 has a bottom electrode 411, a plurality of fixed ribbons 412, and a plurality of movable ribbons 413. The bottom electrode 411 has, for example, a flat plate shape. The fixed ribbons 412 and the movable ribbons 413 are alternately arranged in one direction (X direction) on the bottom electrode 411. The lower surface of each fixed ribbon 412 and the lower surface of each movable ribbon 413 face the upper surface of the bottom electrode 411, respectively. The upper surface of the fixed ribbon 412 is a fixed reflecting surface 412S, and the upper surface of the movable ribbon 413 is a movable reflecting surface 413S. The fixed reflecting surface 412S and the movable reflecting surface 413S are finished to be flat. The plurality of fixed reflecting surfaces 412S and the plurality of movable reflecting surfaces 413S form a light-collecting surface 41S of the spatial light modulator 41.

[0034] The fixed reflecting surface 412S is fixed at a predetermined distance from the bottom electrode 411. The movable reflecting surface 413S is provided so as to be movable in a direction toward and away from the bottom electrode 411 according to an applied voltage (driving voltage).

[0035] The amount of displacement of the movable reflecting surface 413S is adjusted by the magnitude of the potential difference generated by the driving voltage between the movable ribbon 413 and the bottom electrode 411. For example, as shown in the left side of Fig. 3, when the height difference d between the fixed reflecting surface 412S and the movable reflecting surface 413S is zero, the light reflected by the fixed reflecting surface 412S and the light reflected by the movable reflecting surface 413S are in phase, and therefore these lights are emitted from the spatial light modulator 41 as specular reflected light Lr (zeroth-order diffracted light).

[0036] When the wavelength of the incident light Li is λ, if the optical path difference (=2d) between the light reflected by the fixed reflecting surface 412S and the light reflected by the movable reflecting surface 413S is an integer multiple of the wavelength λ (=n×λ (n is an integer equal to or greater than zero)), the light reflected by the fixed reflecting surface 412S and the light reflected by the movable reflecting surface 413S will be in phase. That is, the specular reflected light Lr is emitted from the spatial light modulator 41.

[0037] 3, when the optical path difference (=2d) between the light reflected by the fixed reflecting surface 412S and the light reflected by the movable reflecting surface 413S is an odd multiple of the half wavelength λ / 2, the light reflected by the fixed reflecting surface 412S and the light reflected by the movable reflecting surface 413S have opposite phases and cancel each other out. Therefore, the spatial light modulator 41 does not emit reflected light in the vertical direction, but emits light in an oblique direction, that is, first-order or higher diffracted light (scattered light Ld).

[0038] 3, when the optical path difference (=2d) between the light reflected by the fixed reflecting surface 412S and the light reflected by the movable reflecting surface 413S is neither the wavelength λ nor half the wavelength λ / 2, a part of the incident light Li is emitted as specular reflected light Lr, and the remainder is emitted in an oblique direction as first-order or higher diffracted light (scattered light Ld). That is, according to the magnitude of the height difference d, specular reflected light Lr having an intensity weaker than that of the incident light Li is emitted from the spatial light modulator 41. In this way, in the spatial light modulator 41, it is possible to adjust the intensity of the specular reflected light Lr (or the intensity of the scattered light Ld) by changing the drive voltage.

[0039] The exposure apparatus 100 performs drawing by irradiating the zero-order diffracted light emitted from the spatial light modulator 41 onto the substrate W. Therefore, in terms of the laser light (synthetic line beam LBs) emitted toward the substrate W, when the spatial light modulator 41 is in the state shown on the left side of FIG. 3 (total reflection state) or in the state shown on the right side of FIG. 3, for example, the laser light is emitted, and when the spatial light modulator 41 is in the state shown in the center of FIG. 3, the laser light is not emitted. In the following description, the state shown on the left or right side of FIG. 3 is referred to as the "on state", and the state shown in the center of FIG. 3 is referred to as the "off state". The on state is a state in which light is irradiated from the spatial light modulator 41 toward the substrate W, and the off state is a state in which the light is not irradiated. These are distinguished by the magnitude of the driving voltage applied to the movable ribbon 413.

[0040] The drive voltage can be set individually for each movable ribbon 413. Therefore, it is possible to produce an on state and an off state for each ribbon pair consisting of one movable ribbon 413 and an adjacent fixed ribbon 412. In the following description, the smallest unit for controlling on / off, consisting of a pair of ribbon pairs, is called a channel.

[0041] In the exposure head 4, the spatial light modulator 41 is disposed such that the normal to its focusing surface 41S is inclined with respect to the optical axis. The line beam LB that has passed through the illumination optical system 53 is irradiated onto the focusing surface 41S of the spatial light modulator 41. The state of each channel in the spatial light modulator 41 is then switched by the control unit 90 in accordance with the drawing data, thereby modulating the line beam LB that has entered the spatial light modulator 41. One pixel represented by the drawing data corresponds to one or several channels.

[0042] The spatial light modulator 41 is irradiated with laser light homogenized by the illumination optical system 53. That is, the illumination optical system 53 shapes a linear line beam LB (light having a linear cross section) with a uniform intensity distribution, and irradiates the line beam onto an effective area on the focusing surface 41S of the spatial light modulator 41. Here, the effective area is an area where the spatial light modulator 41 can perform modulation of the incident light. The long axis direction of the line beam LB is set to the x direction, which is the ribbon arrangement direction in the spatial light modulator 41 (see FIG. 2).

[0043] Fig. 4 is a diagram showing the observation optical system 80 of the exposure apparatus 100 shown in Fig. 1. The observation optical system 80 is disposed on the side of the stage 10. The observation optical system 80 is a device for receiving the laser light (synthetic line beam LBs) emitted from the exposure head 4 and observing the laser light.

[0044] The observation optical system 80 includes a dummy substrate 81, an observation camera 83, a case 84, a support frame 85, a beam splitter 86, and a light amount detector 87. The dummy substrate 81 is a light-transmitting substrate formed into a flat plate shape, for example, from quartz glass. The dummy substrate 81 is placed on the upper part of the case 84.

[0045] An observation camera 83 is disposed below the dummy substrate 81 via a beam splitter 86. The observation camera 83 has a two-dimensional image sensor such as a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor. The observation camera 83 captures an image of the laser light incident from the dummy substrate 81 via the beam splitter 86. The dummy substrate 81 and the observation camera 83 are each attached to a case 84 and integrated together. The focal position of the optical system of the observation camera 83 is adjusted to the upper surface 81S of the dummy substrate 81.

[0046] The case 804 is supported so as to be movable up and down by a support frame 85 erected on the support plate 22. The movement of the case 84 in the vertical direction can be controlled by the control unit 90. In this manner, the observation optical system 80 moves integrally with the stage 10 in the horizontal direction (X direction and Y direction), but can move independently of the stage 10 in the vertical direction (Z direction).

[0047] A portion of the laser light that passes through the dummy substrate 81 and enters the observation optical system 80 has its path changed by the beam splitter 86 and enters a light amount detector 87 provided in the case 84. A light collecting optical system (not shown) is provided between the beam splitter 86 and the light amount detector 87. The light collecting optical system collects the light split by the beam splitter 86 and makes it enter the light amount detector 87.

[0048] The light amount detector 87 outputs an electrical signal according to the amount of light incident on the light receiving surface. The light amount detector 87 has, for example, a photodiode. The light amount detector 87 is used for light amount measurement, which will be described later. When the light amount detector 87 is configured as a line sensor, the light amount detector 87 scans the combined line beam by moving the stage 10 in a direction along the major axis direction of the combined line beam (Y direction). This allows a two-dimensional light amount distribution in the minor axis direction and major axis direction of the combined line beam LBs to be measured.

[0049] Fig. 5 is a block diagram showing the control unit 90 shown in Fig. 1. The control unit 90 has a processor such as a CPU, and a storage unit 99 composed of a memory such as a RAM electrically connected to the processor and a storage device such as a hard disk. The processor executes a control program stored in the storage unit 99 to function as a lighting control unit 91, a stage control unit 93, and a drawing control unit 95. Note that at least a part of the functions of the control unit 90 may be realized in hardware by a dedicated circuit.

[0050] The illumination control unit 91 controls the light irradiation unit 5 of the optical unit U to emit a line beam from the light irradiation unit 5 to the exposure head 4. The stage control unit 93 controls the stage moving mechanism 20 to move the stage 10 relative to the exposure head 4. The drawing control unit 95 controls the spatial light modulator 41 based on the drawing data stored in the storage unit 99 to apply a drive voltage to each movable ribbon 413. As a result, the spatial light modulator 41 modulates the combined line beam LBs to correspond to the drawing pattern of the drawing data.

[0051] The writing control unit 95 also has an exposure amount adjustment unit 951. The exposure amount adjustment unit 951 adjusts the exposure amount of the substrate W by the combined line beam LBs according to the line width in the short axis direction of the combined line beam LBs (hereinafter simply referred to as the "line width"). Specifically, the exposure amount adjustment unit 951 acquires the line width in the short axis direction of the combined line beam LBs (hereinafter simply referred to as the "line width") based on an image acquired by the observation camera 83 of the observation optical system 80 or light amount distribution data detected by the light amount detector 87. Then, the exposure amount adjustment unit 951 adjusts the exposure amount of the substrate W by the combined line beam by controlling the spatial light modulator 41 according to the acquired line width of the combined line beam LBs.

[0052] The minor axis direction of the combined line beam LBs corresponds to the Y direction on the detection surface of the observation camera 83 of the observation optical system 80, and corresponds to the Z direction on the detection surface of the light intensity detector 87 (see FIG. 4). The minor axis direction of the combined line beam LBs corresponds to the direction (y direction) perpendicular to the ribbon arrangement direction (x direction) on the focusing surface 41S of the spatial light modulator 41 (see FIG. 2).

[0053] When a pattern is drawn on the substrate W in the exposure apparatus 100, first, the substrate W coated with a photosensitive material is held on the stage 10, and the substrate W is aligned (position adjusted). Then, the stage control unit 93 controls the stage moving mechanism 20 to move the stage 10 in the Y direction (main scanning direction) relative to each exposure head 4. Then, the drawing control unit 95 controls the spatial light modulator 41 according to the position of the stage 10, so that the composite line beam is spatially modulated into a composite line beam corresponding to the drawing pattern of the drawing data, and is irradiated onto the substrate W. As a result, a belt-shaped area extending in the Y direction on the upper surface of the substrate W is exposed. After the movement in the Y direction is completed, the stage 10 is moved in the X direction (sub-scanning direction) by the width of the belt-shaped area. By repeatedly moving the stage in the Y direction and the stage in the X direction, a pattern is drawn on the entire upper surface of the substrate W.

[0054] <About exposure adjustment> Fig. 6 is a diagram showing a correction data generation flow executed by the exposure amount adjustment unit 951. The correction data acquired by the flow of Fig. 6 is used by the exposure amount adjustment unit 951 to adjust the exposure amount of the combined line beam LBs for the substrate W when actually performing exposure on the substrate W. For this reason, the correction data generation flow shown in Fig. 6 is executed in advance before actually performing exposure on the substrate W in the exposure apparatus 100.

[0055] In addition, when the exposure adjustment unit 951 performs the correction data generation flow, it is assumed that the combined line beam is first irradiated from the exposure head 4 to the observation optical system 80, thereby making it possible to observe the combined line beam.

[0056] First, the exposure amount adjustment unit 951 acquires the line width in the short axis direction of the combined line beam LBs (step S1) using an image acquired by the observation camera 83 or light amount distribution data acquired by the light amount detector 87. Specifically, in step S1, the exposure amount adjustment unit 951 acquires the line width of the combined line beam LBs at a plurality of different positions in the long axis direction of the combined line beam LBs.

[0057] 7 and 8 are diagrams illustrating a combined line beam LBs formed on the focusing surface 41S of the spatial light modulator 41. For ease of explanation, only three line beams LB1 to LB3 are shown among the multiple line beams LB in Fig. 7 and Fig. 8.

[0058] FIG. 7 shows a case where the overlapping of the multiple line beams LB1 to LB3 is highly accurate. That is, the incident positions of the multiple line beams LB1 to LB3 with respect to the focusing surface 41S are irradiated to the center in the y direction (that is, the center of the fixed reflecting surface 412S and the movable reflecting surface 413S). As shown in FIG. 7, when the multiple line beams LB are overlapped with high accuracy, the composite line beam LBs has a linear shape with a uniform line width. Therefore, in step S1, if the exposure amount adjustment unit 951 acquires line widths at three positions, namely, position x1 near the -x side, position x2 near the center, and position x3 near the +x side, the line widths will be the same value (W1) in all cases.

[0059] 8 shows a case where the overlapping accuracy of the multiple line beams LB1 to LB3 is low. Specifically, the -x side end of the line beam LB3 overlaps with the other line beams LB1 and LB2, while the +x side end of the line beam LB3 is shifted to the -y side with respect to the other line beams LB1 and LB2.

[0060] In the case of the combined line beam LBs shown in Fig. 8, the line width gradually increases as it moves in the +x direction. Therefore, in step S1, when the combined line beam LBs shown in Fig. 8 is observed by the observation optical system 80, the line width of the combined line beam LBs gradually increases as it moves in the +x direction. For example, in step S1, when the exposure amount adjustment unit 951 acquires the line widths at positions x1, x2, and x3, the acquired line widths increase in the order of positions x1, x2, and x3.

[0061] 6, after step S1, the exposure dose adjustment unit 951 uses the line widths at the multiple points acquired in step S1 to acquire the line widths at the positions where the line widths are not measured by an interpolation process such as linear interpolation (step S2). In step S2, the line width distribution in the major axis direction is acquired for the combined line beam LBs.

[0062] After step S2, the exposure amount adjustment unit 951 generates intensity correction data (step S3). The intensity correction data is data used to correct the intensity of the combined line beam LBs when exposing the substrate W. The intensity of the combined line beam LBs can be adjusted by changing the magnitude of the driving voltage applied by the writing control unit 95 to each channel of the spatial light modulator 41.

[0063] After step S2, the exposure amount adjustment unit 951 generates exposure time correction data (step S4). The exposure time correction data is data used to correct the exposure time of the combined line beam LBs when exposing the substrate W. The exposure time means the light irradiation time set for exposing one pixel of the drawing data. The exposure time can be adjusted by changing the length of time for which the drawing control unit 95 applies a drive voltage to each channel of the spatial light modulator 41.

[0064] For example, in the case of the combined line beam LBs shown in FIG. 7, the line width is uniform in the long axis direction. Therefore, the intensity distribution of the combined line beam LBs in the long axis direction is uniform. When exposure is performed with such a combined line beam LBs, the exposure amount can be made uniform in the long axis direction. Therefore, correction of the intensity distribution is not required. Also, adjustment of the exposure time is not required.

[0065] On the other hand, in the case of the combined line beam LBs shown in FIG. 8, the line width gradually increases as it moves toward the +x side. In general, the reflection efficiency of the fixed reflecting surface 412S and the movable reflecting surface 413S is highest near the center in the y direction, and decreases toward the end in the y direction. In such a case, the reflection intensity is relatively high at the position x1 where the line width is small, and the reflection efficiency is relatively low at the position x3 where the line width is wide. When the substrate W is exposed with such combined line beam LBs, the exposure amount is relatively large at the position x1 where the line width is small, and the exposure amount is relatively small at the position x3 where the line width is large. That is, unevenness occurs in the exposure amount. Therefore, in step S3, the exposure amount adjustment unit 951 generates intensity correction data for adjusting the intensity of the combined line beam LBs so that the intensity is weakened toward the -x side and conversely, the intensity is strengthened toward the +x side.

[0066] Furthermore, when the line width is large, the exposure range is relatively wider than when the line width is small, and the exposure time per pixel is relatively longer. When the exposure time is relatively longer, the exposure amount per pixel is relatively larger. This causes unevenness in the exposure amount. Therefore, in step S4, the exposure amount adjustment unit 951 generates exposure time correction data that adjusts the exposure time of the combined line beam LBs so that the exposure time becomes shorter as the line width becomes larger.

[0067] The exposure amount adjustment unit 951 stores the intensity correction data and the exposure time correction data generated in steps S3 and S4 in the storage unit 99 (step S5). With this, the exposure amount adjustment unit 951 ends the correction data acquisition process.

[0068] When the substrate W is actually exposed in the exposure apparatus 100, the exposure amount adjustment unit 951 corrects the intensity and exposure time of the combined line beam LBs using the intensity correction data and the exposure time correction data, respectively. That is, the exposure amount adjustment unit 951 adjusts the exposure amount of the substrate W by the combined line beam LBs according to the line width of the line beam LB. As a result, even if the accuracy of overlapping of the multiple line beams LB is low, unevenness in the exposure amount can be reduced by adjusting the exposure amount of the substrate W by the combined line beam LBs. Therefore, the line width of the pattern after patterning can be made uniform. In addition, the adjustment work of the illumination optical system 53 for increasing the accuracy of overlapping of the multiple line beams LB can be reduced.

[0069] Furthermore, by providing observation optical system 80, the line width of combined line beam LBs can be measured in exposure apparatus 100, thereby eliminating the need to measure the line width with a separate apparatus.

[0070] <2. Modification> Although the embodiment has been described above, the present invention is not limited to the above, and various modifications are possible.

[0071] For example, in the above embodiment, the exposure amount adjustment unit 951 adjusts the intensity and exposure time of the combined line beam LBs in order to adjust the exposure amount of the substrate W by the combined line beam LBs. However, the exposure amount adjustment unit 951 may be configured to adjust only one of them.

[0072] In the above embodiment, the spatial light modulator 41 is a GLV, which is a diffractive modulation element. However, it may be a MEMS (Micro Electro Mechanical System), such as a DMD, that is other than a diffractive modulation element.

[0073] Although the present invention has been described in detail, the above description is merely illustrative in all respects, and the present invention is not limited thereto. It is understood that countless variations not illustrated can be envisioned without departing from the scope of the present invention. The configurations described in the above embodiments and variations can be appropriately combined or omitted as long as they are not mutually contradictory. [Explanation of symbols]

[0074] 10: Stage 41: Spatial light modulator 43: Projection optical system 53:Illumination optical system 61:Light source section 100: Exposure equipment 951: Exposure control unit LB1: Line beam LB2: Line beam LB3: Line beam LBs: Synthetic line beam W: Substrate

Claims

1. An exposure apparatus comprising: A stage for holding the substrate; an illumination optical system that forms light from a plurality of light sources into a plurality of line beams and superimposes the line beams at a predetermined focal position; a spatial light modulator that spatially modulates a composite line beam formed by superposing the plurality of line beams by the illumination optical system; a projection optical system that projects the combined line beam that has been spatially modulated by the spatial light modulator onto a substrate held by the stage; an exposure amount adjustment unit that adjusts an exposure amount of the substrate by the combined line beam in accordance with a line width of the combined line beam in a minor axis direction; An exposure apparatus comprising:

2. 2. The exposure apparatus according to claim 1, an observation unit capable of measuring a line width of the combined line beam; The exposure apparatus further comprises:

3. 3. The exposure apparatus according to claim 1, The light amount adjusting unit adjusts an exposure time for exposing the substrate for each channel of the spatial light modulator in accordance with the line width.

4. 3. The exposure apparatus according to claim 1, An exposure apparatus, wherein the light amount adjustment unit adjusts the intensity of the combined beam for each channel of the spatial light modulator in accordance with the line width.

5. An exposure method comprising the steps of: holding the substrate on a stage; forming light from a plurality of light sources into a plurality of line beams in an illumination optical system and superimposing the line beams at a predetermined focal position; a step of spatially modulating a composite line beam formed by superposing the plurality of line beams by the illumination optical system using a spatial light modulator; projecting the combined line beam, which has been spatially modulated by the spatial light modulator, onto a substrate held by the stage using a projection optical system; adjusting an exposure dose of the substrate by the combined line beam in response to a line width of the combined line beam in a major axis direction; An exposure method comprising:

Images