JP6227347B2 - Exposure apparatus and optical apparatus - Google Patents

Description

  The present invention relates to a technique for exposing a substrate by irradiating the substrate with spatially modulated light.

  When forming a pattern such as a circuit on the photosensitive material applied on the substrate, the light emitted from the light source is subjected to spatial modulation according to the CAD data representing the pattern, and the spatially modulated light is used on the substrate. In recent years, an exposure apparatus (so-called drawing apparatus) that directly exposes a pattern on the photosensitive material by scanning the photosensitive material has attracted attention. As a spatial light modulator that applies spatial modulation to light, for example, GLV (Grating Light Valve) (“GLV” is a registered trademark) is known (see Patent Document 1).

JP 2012-93701 A

  The spatial light modulator receives light emitted from a light source on a modulation surface (for example, a ribbon arrangement surface in the case of GLV), and performs spatial modulation on the received light.

  By the way, for example, the exposure apparatus is not thermally stable immediately after startup or after a long period of non-use, and in a thermally unstable state, it is caused by thermal deformation accompanying the temperature rise of each member. Thus, the light emitted from the light source tends to fluctuate. Even after the exposure apparatus is thermally stabilized, the light emitted from the light source may fluctuate due to drift characteristics of the light source. When the light emitted from the light source fluctuates, the light enters the position shifted from the determined position on the modulation surface of the spatial light modulator. The positional deviation of the light incident on the modulation surface appears as a deviation of the irradiation position of the light on the substrate. Thus, if there is an abnormality in the state of the light incident on the modulation surface, there is a possibility that appropriate exposure processing cannot be ensured.

  In the prior art, there is no way to grasp the light state on the modulation surface. For this reason, for example, even if light is incident on a position shifted from a predetermined position on the modulation surface, this cannot be detected at an early stage, leading to a decrease in yield.

  The present invention has been made in view of the above problems, and an object thereof is to provide a technique capable of accurately grasping the state of light on the modulation surface of a spatial light modulator.

A first aspect is an exposure apparatus that irradiates a substrate with spatially modulated light to expose the substrate, and includes a holding unit that holds the substrate and an optical device that forms the spatially modulated light. A light source unit that emits light; and an observation unit that receives a part of the light emitted from the light source unit through the observation target surface and acquires imaging data of the observation target surface; The remaining light emitted from the light source unit is received by a modulation surface, and the received light is subjected to spatial modulation according to pattern data, and the imaging data acquired by the observation unit A state estimation unit that identifies a light state on the observation target surface and estimates the identified light state as a light state on the modulation surface, and from the light source unit to the observation target Optical distance to the surface and from the light source to the modulation surface. And optical distance is equal.

A second aspect is the exposure apparatus according to the first aspect, wherein the state estimation unit specifies an incident position of light on the observation target surface based on the imaging data acquired by the observation unit, The identified light incident position is estimated as the light incident position on the modulation surface.

A third aspect is an exposure apparatus according to the second aspect, in which the light emitted from the light source unit travels based on the incident position of light on the modulation surface estimated by the state estimation unit; A correction unit that adjusts a relative positional relationship with the modulation surface.

A 4th aspect is an exposure apparatus which concerns on a 3rd aspect, Comprising: The said optical apparatus is provided with the 1st lens which converges the light radiate | emitted from the said light source part on the said modulation surface, The said correction | amendment part However, the relative positional relationship is changed by displacing the first lens.

A fifth aspect is the exposure apparatus according to the fourth aspect, wherein the optical device includes a second lens that converges the light emitted from the light source unit onto the observation target surface, and the light source The optical distance from the part to the first lens is equal to the optical distance from the light source part to the second lens.

A sixth aspect is an optical device that forms light subjected to spatial modulation, and receives a light source unit that emits light and a part of the light emitted from the light source unit through an observation target surface. Then, the remaining light emitted from the observation unit for acquiring imaging data of the observation target surface and the light source unit is received by the modulation surface, and the received light is subjected to spatial modulation according to the pattern data. Based on the imaging data acquired by the spatial light modulator and the observation unit, the state of light on the surface to be observed is specified, and the state of the specified light is estimated as the state of light on the modulation surface. A state estimation unit, and an optical distance from the light source unit to the observation target surface is equal to an optical distance from the light source unit to the modulation surface.

According to the first and sixth aspects, it is possible to acquire imaging data on the observation target surface of the light emitted from the light source unit. Here, since the optical distance from the light source unit to the observation target surface is equal to the optical distance from the light source unit to the modulation surface, the light state on the observation target surface (in particular, the light state depending on the optical distance) is modulated. It can be estimated that it is equal to the state of light on the surface. Therefore, it is possible to accurately grasp the state of light on the modulation surface of the spatial light modulator from the imaging data acquired by the observation unit.

In addition, a state estimation unit that estimates the light state on the modulation surface based on the imaging data acquired by the observation unit is provided. Therefore, for example, when there is an abnormality in the light state on the modulation surface, this can be detected quickly.

According to the second aspect, the state estimation unit estimates the light incident position on the modulation surface based on the imaging data acquired by the observation unit. Therefore, for example, when the incident position of light on the modulation surface deviates from the ideal position, this can be detected quickly.

According to the third aspect, the correction unit determines the relative positional relationship between the optical path on which the light emitted from the light source unit travels and the modulation surface based on the incident position of the light on the modulation surface estimated by the state estimation unit. adjust. According to this configuration, for example, when the estimated incident position is deviated from the ideal position, the actual incident position of light on the modulation surface can be brought closer to the ideal position by changing the relative positional relationship. it can. Thereby, it is possible to suppress a decrease in exposure position accuracy.

According to the fourth aspect, the relative positional relationship between the optical path along which the light emitted from the light source unit travels and the modulation surface is changed by displacing the first lens. According to this configuration, the actual incident position of light on the modulation surface can be changed with a simple configuration.

According to the fifth aspect, the optical distance between the second lens that converges light on the observation target surface and the light source unit is the optical distance between the first lens that converges light on the modulation surface and the light source unit; equal. According to this configuration, the history of light emitted from the light source unit and incident on the observation target surface is equal to the history of light emitted from the light source unit and incident on the modulation surface. Therefore, the state of light on the modulation surface of the spatial light modulator can be estimated particularly accurately from the imaging data acquired by the observation unit.

It is a side view of exposure apparatus. It is a top view of exposure apparatus. It is a figure which shows an exposure head typically. It is a block diagram which shows the hardware constitutions of a control part. It is a figure which shows typically a partial structure of an exposure unit. It is a figure which shows a lens displacement mechanism typically. It is a figure which shows the flow of the process performed in exposure apparatus. It is a figure for demonstrating a drawing process.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiment is an example embodying the present invention, and is not an example of limiting the technical scope of the present invention. In each of the drawings referred to in the following description, a common XYZ orthogonal coordinate system and θ axis are appropriately attached in order to clarify the positional relationship and operation direction of each member. In the drawings, the size and number of each part may be exaggerated or simplified for easy understanding.

<1. Overall Configuration of Exposure Apparatus 1>
The configuration of the exposure apparatus 1 will be described with reference to FIGS. FIG. 1 is a side view schematically showing the configuration of the exposure apparatus 1. FIG. 2 is a plan view schematically showing the configuration of the exposure apparatus 1. In FIGS. 1 and 2, a part of the cover panel 12 is not shown for convenience of explanation.

  The exposure apparatus 1 exposes a pattern (for example, a circuit pattern) by irradiating light (drawing light) spatially modulated in accordance with CAD data or the like onto the upper surface of the substrate W on which a layer of a photosensitive material such as a resist is formed. (Drawing) device (so-called drawing device). The substrate W to be processed by the exposure apparatus 1 is, for example, a color filter substrate provided in a semiconductor substrate, a printed board, a liquid crystal display device, etc., a flat panel provided in a liquid crystal display device, a plasma display device, or the like. Glass substrates for displays, magnetic disk substrates, optical disk substrates, solar cell panels, and the like. In the illustrated example, a circular semiconductor substrate is illustrated as the substrate W.

  The exposure apparatus 1 has a structure in which a cover panel 12 is attached to a ceiling surface, a floor surface, and a peripheral surface of a skeleton composed of a main body frame 11. The main body frame 11 and the cover panel 12 form a casing of the exposure apparatus 1. The internal space of the casing of the exposure apparatus 1 (that is, the space surrounded by the cover panel 12) is divided into a delivery area 13 and a processing area 14. A base 15 is disposed in the processing area 14. A gate-shaped support frame 16 is erected on the base 15.

  The exposure apparatus 1 includes a transport device 2, a pre-alignment unit 3, a stage 4, a stage drive mechanism 5, a stage position measurement unit 6, a mark imaging unit 7, an exposure unit 8, and a control unit 9. Each of these components is arranged inside the casing of the exposure apparatus 1 (that is, the transfer area 13 and the processing area 14) or outside the casing (that is, the space outside the main body frame 11). Hereinafter, each of these components will be specifically described.

<Transport device 2>
The transport device 2 transports the substrate W. The transfer device 2 is disposed in the transfer area 13 and carries the substrate W in and out of the processing area 14. Specifically, the transport apparatus 2 includes, for example, two hands 21 and 21 for supporting the substrate W, and a hand drive mechanism 22 that moves the hands 21 and 21 independently (advancement and retraction and elevating movement), Is provided.

  A cassette placing portion 17 for placing the cassette C is disposed outside the housing of the exposure apparatus 1 and adjacent to the transfer area 13. The transport device 2 is provided with the cassette placing portion 17. The unprocessed substrate W accommodated in the cassette C placed on the substrate is taken out and loaded into the processing region 14, and the processed substrate W is unloaded from the processing region 14 and accommodated in the cassette C. In addition, delivery of the cassette C with respect to the cassette mounting part 17 is performed by an external conveyance apparatus (illustration omitted).

<Pre-alignment unit 3>
The pre-alignment unit 3 performs a process (pre-alignment process) for roughly correcting the rotational position of the substrate W before the substrate W is placed on the stage 4 described later. The pre-alignment unit 3 includes, for example, a mounting table that is configured to be rotatable, and a notch (for example, a notch, an orientation flat, or the like) formed in a part of the outer peripheral edge of the substrate W mounted on the mounting table. It can comprise including the sensor which detects a position, and the rotation mechanism which rotates a mounting base. In this case, in the pre-alignment process in the pre-alignment unit 3, first, the position of the notch portion of the substrate W placed on the mounting table is detected by a sensor, and then the rotation mechanism determines whether the position of the notch portion is the same. This is performed by rotating the mounting table so as to be in a predetermined position.

<Stage 4>
The stage 4 is a holding unit that holds the substrate W inside the housing. The stage 4 is disposed on a base 15 disposed in the processing region 14. Specifically, the stage 4 has, for example, a flat plate-like outer shape, and places and holds the substrate W on the upper surface thereof in a horizontal posture. A plurality of suction holes (not shown) are formed on the upper surface of the stage 4, and a negative pressure (suction pressure) is formed in the suction holes, whereby the substrate W placed on the stage 4 is placed on the stage 4. It can be fixedly held on the upper surface of the.

<Stage drive mechanism 5>
The stage drive mechanism 5 moves the stage 4 relative to the base 15. The stage drive mechanism 5 is disposed on a base 15 disposed in the processing region 14.

  Specifically, the stage drive mechanism 5 includes a rotation mechanism 51 that rotates the stage 4 in the rotation direction (rotation direction around the Z axis (θ axis direction)), and a support plate that supports the stage 4 via the rotation mechanism 51. 52 and a sub-scanning mechanism 53 that moves the support plate 52 in the sub-scanning direction (X-axis direction). The stage drive mechanism 5 further includes a base plate 54 that supports the support plate 52 via the sub-scanning mechanism 53, and a main scanning mechanism 55 that moves the base plate 54 in the main scanning direction (Y-axis direction).

  The rotation mechanism 51 rotates the stage 4 about a rotation axis A that passes through the center of the upper surface of the stage 4 (mounting surface of the substrate W) and is perpendicular to the mounting surface. For example, the rotation mechanism 51 is provided at the lower end of the rotation shaft portion 511 and the lower end of the rotation shaft portion 511 that is fixed to the back surface side of the mounting surface and extends along the vertical axis, and rotates the rotation shaft portion 511. A rotation drive unit (for example, a rotation motor) 512 may be included. In this configuration, the rotation drive unit 512 rotates the rotation shaft portion 511, so that the stage 4 rotates about the rotation axis A in the horizontal plane.

  The sub-scanning mechanism 53 has a linear motor 531 configured by a mover attached to the lower surface of the support plate 52 and a stator laid on the upper surface of the base plate 54. The base plate 54 is provided with a pair of guide members 532 extending in the sub-scanning direction. The guide members 532 slide between the guide members 532 and the support plate 52 while sliding on the guide members 532. Ball bearings that can move along are installed. That is, the support plate 52 is supported on the pair of guide members 532 via the ball bearing. When the linear motor 531 is operated in this configuration, the support plate 52 moves smoothly along the sub-scanning direction while being guided by the guide member 532.

  The main scanning mechanism 55 includes a linear motor 551 that includes a moving element attached to the lower surface of the base plate 54 and a stator laid on the base 15. In addition, a pair of guide members 552 extending in the main scanning direction is laid on the base 15, and an air bearing, for example, is installed between each guide member 552 and the base plate 54. Air is always supplied from utility equipment to the air bearing, and the base plate 54 is levitated and supported on the guide member 552 by the air bearing in a non-contact manner. When the linear motor 551 is operated in this configuration, the base plate 54 smoothly moves without friction along the main scanning direction while being guided by the guide member 552.

<Stage position measurement unit 6>
The stage position measurement unit 6 measures the position of the stage 4. Specifically, for example, the stage position measurement unit 6 emits laser light from outside the stage 4 toward the stage 4 and receives the reflected light, and the position of the stage 4 is determined from the interference between the reflected light and the emitted light. Specifically, it is constituted by an interference type laser length measuring device that measures the Y position along the main scanning direction and the θ position along the rotation direction.

<Mark imaging unit 7>
The mark imaging unit 7 is an optical device that images the upper surface of the substrate W held on the stage 4. The mark imaging unit 7 is supported by the support frame 16. Specifically, the mark imaging unit 7 includes, for example, a lens barrel, a focusing lens, a CCD image sensor, and a drive unit. The lens barrel is an illumination unit (that is, illumination light for imaging (however, light having a wavelength that does not sensitize the resist on the substrate W or the like is selected as illumination light) arranged outside the housing of the exposure apparatus 1. ) And a lighting unit) 700) are connected via a fiber cable or the like. The CCD image sensor is composed of an area image sensor (two-dimensional image sensor) or the like. The drive unit is configured by a motor or the like, and drives the focusing lens to change its height position. The drive unit adjusts the height position of the focusing lens to perform autofocus.

  In the mark imaging unit 7 having such a configuration, the light emitted from the illumination unit 700 is introduced into the lens barrel and guided to the upper surface of the substrate W on the stage 4 through the focusing lens. The reflected light is received by the CCD image sensor. Thereby, imaging data of the upper surface of the substrate W is acquired. This imaging data is sent to the control unit 9 and used for alignment (positioning) of the substrate W.

<Exposure unit 8>
The exposure unit 8 is an optical device that forms drawing light. The exposure apparatus 1 includes two exposure units 8. However, the number of the exposure units 8 that are mounted is not necessarily two, and may be one or three or more. When the exposure apparatus 1 includes a plurality of exposure units 8, each of the exposure units 8 has the same configuration.

  The exposure unit 8 includes a light source unit 81 and an exposure head 80. The exposure head 80 includes a modulation unit 82 and a projection optical system 83. These parts 81, 82, 83 are supported by the support frame 16. Specifically, for example, the light source unit 81 is accommodated in an accommodation box placed on the top plate of the support frame 16. The modulation unit 82 and the projection optical system 83 are accommodated in an accommodation box fixed to the + Y side of the support frame 18. The exposure unit 8 further includes a monitoring unit 60 and a correction unit 70. These units 60 and 70 will be described later.

  Each element 81, 82, 83 provided in the exposure unit 8 will be described with reference to FIG. 3 in addition to FIGS. FIG. 3 is a view schematically showing the exposure head 80.

a. Light source 81
The light source unit 81 emits light toward the exposure head 80. Specifically, the light source unit 81 includes, for example, a laser driving unit 811 and a laser oscillator 812 that receives driving from the laser driving unit 811 and emits laser light from an output mirror (not shown). Further, the light source unit 81 converts the light (spot beam) emitted from the laser oscillator 812 into linear light having a uniform intensity distribution (that is, a line beam having a light beam cross-section band-shaped light) 813. Is provided.

  The light source unit 81 further includes a drawing focus lens 814 (first lens) that converges the line beam emitted from the illumination optical system 813 onto a modulation surface 820 (described later) of the spatial light modulator 821. The drawing focus lens 814 is constituted by, for example, a cylindrical lens, and is arranged so that its cylindrical surface (cylindrical surface) faces the upstream side of incident light (see FIG. 5). Further, the drawing focus lens 814 is arranged at a height position at which the line beam emitted from the illumination optical system 813 is incident on the center line (hereinafter, such a height position is referred to as the drawing focus lens 814). Also referred to as “reference position” of the focus lens 814). However, as will become apparent later, the drawing focus lens 814 is provided with a mechanism (lens displacement mechanism 71) for changing its height position (position along the Z direction). In some cases, it is arranged at a position higher (or lower) than the reference position.

  In the light source unit 81 having such a configuration, laser light is emitted from the laser oscillator 812 under the drive of the laser driving unit 811, and the laser light is converted into a line beam in the illumination optical system 813. The line beam emitted from the illumination optical system 813 enters the drawing focus lens 814, exits from the cylindrical surface, and converges on the modulation surface 820 of the modulation unit 82 (see FIG. 5). That is, the modulation surface 820 is a line beam condensing surface.

b. Modulation unit 82
The modulation unit 82 performs spatial modulation according to the pattern data D on the light incident here. However, “to spatially modulate light” means to change the spatial distribution (amplitude, phase, polarization, etc.) of light. “Pattern data D” is data in which position information on the substrate W to be irradiated with light is recorded in units of pixels. For example, pattern design data generated using CAD (Computer Aided Design). Is generated by rasterizing. The pattern data D is acquired, for example, by being received from an external terminal device connected via a network or the like, or by being read from a recording medium, and stored in the storage device 94 of the control unit 9 described later (FIG. 4).

  The modulation unit 82 includes a spatial light modulator 821. The spatial light modulator 821 is a device that, for example, spatially modulates light by electrical control to reflect necessary light that contributes to pattern drawing and unnecessary light that does not contribute to pattern drawing in different directions. .

  In the spatial light modulator 821, for example, a fixed ribbon and a movable ribbon, which are modulation elements, are arranged one-dimensionally so that the upper surfaces thereof are along the same surface (hereinafter also referred to as “modulation surface”) 820. And a diffraction grating type spatial light modulator (for example, GLV). In the diffraction grating type spatial light modulator 821, a predetermined number of fixed ribbons and a predetermined number of movable ribbons form one modulation unit, and this modulation unit is one-dimensionally along the X-axis direction. It has a configuration in which a plurality are arranged. The operation of each modulation unit is controlled by turning on / off the voltage. A state in which necessary light contributing to pattern drawing is emitted by switching the voltage state (for example, the surface of the modulation unit is flat). And a state in which unnecessary light that does not contribute to pattern drawing is emitted (for example, one or more parallel grooves having a depth determined on the surface of the modulation unit are periodically arranged). In a state where the diffracted light of the order other than the 0th order is emitted). The spatial light modulator 821 includes a driver circuit unit that can independently apply a voltage to each of a plurality of modulation units, and the voltage of each modulation unit can be switched independently.

  In the modulation unit 82, the light (line beam) emitted from the illumination optical system 813 is switched under the control of the control unit 9 while the state of each modulation unit of the spatial light modulator 821 is switched according to the pattern data D. Then, the light is incident on the modulation surface 820 of the spatial light modulator 821 through the mirror 822 at a predetermined angle. However, the line beam has a plurality of lines arranged in a line so that the long-width direction of the linear beam cross section is along the arrangement direction (X-axis direction) of the plurality of modulation units of the spatial light modulator 821. Incident to the modulation unit. Therefore, the light emitted from the spatial light modulator 821 is light that is spatially modulated for a plurality of pixels along the sub-scanning direction (however, light that is spatially modulated in one modulation unit is equivalent to one pixel). The light has a band-like drawing light. As described above, the spatial light modulator 821 receives the light emitted from the light source unit 81 by the modulation surface 820 and performs spatial modulation according to the pattern data D on the received light.

c. Projection optical system 83
The projection optical system 83 blocks unnecessary light out of the drawing light emitted from the spatial light modulator 821 and guides the necessary light to the surface of the substrate W to form an image of the necessary light on the surface of the substrate W. That is, the drawing light emitted from the spatial light modulator 821 includes necessary light and unnecessary light. The necessary light travels in the −Z direction along the Z axis, and the unnecessary light is ± X from the Z axis. Proceed in the -Z direction along an axis slightly inclined in the direction. The projection optical system 83 includes, for example, a blocking plate 831 having a through hole formed in the middle so that only necessary light passes, and the blocking plate 831 blocks unnecessary light. In addition to the blocking plate 831, the projection optical system 83 defines a blocking plate 832 that blocks ghost light, a plurality of lenses 833 and 834 that form a zoom unit that widens (or narrows) the necessary light, and necessary light. Further, a focusing lens 835 that forms an image on the substrate W with a given magnification, a driving unit (for example, a motor) (not shown) that performs autofocus by driving the focusing lens 835 and changing its height position, and the like are further provided. included.

  In the exposure apparatus 1, as will be described later, each exposure unit 8 having the above configuration is moved in the sub-scanning direction while being moved relative to the substrate W along the main scanning direction (Y-axis direction). Continue to irradiate the drawing light for a plurality of pixels along. A pattern group is drawn on the entire drawing target area in the main surface of the substrate W by repeatedly performing main scanning with irradiation of drawing light from each exposure unit 8 with the sub scanning interposed therebetween. (See FIG. 8).

<Control unit 9>
The control unit 9 is electrically connected to each unit included in the exposure apparatus 1 and controls the operation of each unit of the exposure apparatus 1 while executing various arithmetic processes.

  For example, as shown in FIG. 4, the control unit 9 includes a general computer in which a CPU 91, a ROM 92, a RAM 93, a storage device 94, and the like are interconnected via a bus line 95. The ROM 92 stores basic programs and the like, and the RAM 93 is used as a work area when the CPU 91 performs predetermined processing. The storage device 94 is configured by a nonvolatile storage device such as a flash memory or a hard disk device. A program P is stored in the storage device 94, and various functions (for example, a state estimation unit 64, which will be described later, change) are performed by the CPU 91 as a main control unit performing arithmetic processing according to the procedure described in the program P. The control unit 72 and the like). The program P is normally stored and used in advance in a memory such as the storage device 94, but is recorded in a recording medium such as a CD-ROM or DVD-ROM or an external flash memory (program product). (Or provided by downloading from an external server via a network) and may be additionally or exchanged and stored in a memory such as the storage device 94. Note that some or all of the functions realized in the control unit 9 may be realized in hardware by a dedicated logic circuit or the like.

  In the control unit 9, an input unit 96, a display unit 97, and a communication unit 98 are also connected to the bus line 95. The input unit 96 is an input device composed of, for example, a keyboard and a mouse, and accepts various operations (operations such as inputting commands and various data) from the operator. The input unit 96 may be configured with various switches, a touch panel, and the like. The display unit 97 is a display device that includes a liquid crystal display device, a lamp, and the like, and displays various types of information under the control of the CPU 91. The communication unit 98 has a data communication function for transmitting / receiving commands and data to / from an external device via a network.

<2. Monitoring unit 60>
As described above, in the exposure unit 8, the light (line beam) emitted from the light source unit 81 enters the modulation surface 820 of the spatial light modulator 821 through the drawing focus lens 814. Here, the exposure unit 8 includes a monitoring unit 60 that monitors the state of light on the modulation surface 820.

  The monitoring unit 60 will be specifically described with reference to FIG. FIG. 5 schematically shows a part of the configuration of the exposure unit 8. The monitoring unit 60 includes a branching unit 61, an observation focus lens (second lens) 62, an observation unit 63, and a state estimation unit 64.

<Branch 61>
The branching unit 61 transmits most of light (for example, 99%) that passes through the branching unit 61, and branches the remaining (for example, the remaining 1%) in a direction different from the traveling direction of the transmitted light. It is a component, and is constituted by, for example, a beam splitter. The branching unit 61 is disposed on the optical path of the light L emitted from the light source unit 81 and directed to the modulation unit 82, and in front of the drawing focus lens 814 (that is, on the light source unit 81 side). That is, the branching unit 61 branches a part of the light L emitted from the light source unit 81 in a direction different from the direction toward the modulation unit 82 at a position before the drawing focus lens 814.

  Hereinafter, the light that passes through the branching portion 61 and travels toward the modulation unit 82 is also referred to as “drawing light L1”. Further, the light branched in the branching unit 61 in a direction different from the direction toward the modulation unit 82 is also referred to as “observation light L2”. The drawing light L 1 is guided to the spatial light modulator 821 through the drawing focus lens 814 and the mirror 822. On the other hand, the observation light L 2 is guided to the observation unit 63 via the mirror 600 and the observation focus lens 62.

<Focus lens 62 for observation>
The observation focus lens 62 applies a part of the light L emitted from the light source unit 81 (specifically, the observation light L2 branched by the branching unit 61) to an observation target surface 630 (described later). ) To converge.

  The observation focus lens 62 is arranged symmetrically with the drawing focus lens 814 (however, the drawing focus lens 814 at the reference position) with the branch portion 61 as the center. That is, the observation focus lens 62 is disposed at a position where the optical distance from the branching portion 61 to the observation focus lens 62 is equal to the optical distance from the branching portion 61 to the drawing focus lens 814 at the reference position. Is done. That is, the optical distance from the light source unit 81 to the observation focus lens 62 is equal to the optical distance from the light source unit 81 to the drawing focus lens 814 at the reference position. The observation focus lens 62 is a cylindrical lens having the same focal length as the drawing focus lens 814 (more preferably, at least one of the lens thickness, the radius of curvature, the material, and the like is the same as the drawing focus lens 814). Lens) and is arranged so that its cylindrical surface faces the upstream side of the incident light. Further, the observation focus lens 62 is disposed at a height position where the observation light L2 is incident on the center line thereof.

  As described above, the focal length of the observation focus lens 62 and the focal length of the drawing focus lens 814 are equal. Therefore, in the state where the drawing focus lens 814 is disposed at the reference position, the optical distance between the observation focus lens 62 and the observation target surface 630 on which the observation light L2 converges, the drawing focus lens 814, and This is equal to the optical distance from the modulation surface 820 for converging the drawing light L1. As described above, since the optical distance from the light source unit 81 to the observation focus lens 62 is equal to the optical distance from the light source unit 81 to the drawing focus lens 814, the optical distance from the light source unit 81 to the observation target surface 630 is The optical distance from the light source unit 81 to the modulation surface 820 is equal.

<Observation unit 63>
The observation unit 63 receives a part of the light L emitted from the light source unit 81 (specifically, the observation light L2 branched by the branching unit 61) via the observation target surface 630, and receives the observation target. Image data of the surface 630 is acquired. That is, the observation unit 63 images the observation light L2 incident on the observation target surface 630.

  Specifically, the observation unit 63 includes, for example, an optical microscope (optical observation microscope) 631 and an image sensor 632 (so-called optical microscope with a camera). The optical microscope 631 is an optical device that forms an observation image of the observation target surface 630 and includes an objective lens 6311 and a lens barrel 6312. However, the focal position of the objective lens 6311 coincides with the observation target surface 630. The image sensor 632 is composed of, for example, a photoelectric conversion element such as a CCD or a CMOS that converts light into an electric signal, and converts image information of an observation image of the observation target surface 630 acquired from the optical microscope 631 into an electric signal. The imaging data of the observation target surface 630 is acquired. This imaging data is output to the control unit 9 (specifically, the state estimation unit 64 realized by the control unit 9).

<State estimation unit 64>
The state estimation unit 64 estimates the light state (for example, the incident position of light) on the modulation surface 820 based on the imaging data acquired by the observation unit 63 (that is, imaging data of the observation target surface 630). . Specifically, the state estimation unit 64 performs image analysis on the imaging data acquired by the observation unit 63, identifies the incident position of light (that is, the observation light L2) on the observation target surface 630, and is identified. The incident position is estimated as the incident position of the light on the modulation surface 820 (that is, the drawing light L1). The incident position of the drawing light L1 on the modulation surface 820 estimated by the state estimating unit 64 is hereinafter also referred to as “estimated incident position”.

  However, the “light state” estimated by the state estimation unit 64 is not limited to the incident position of light, and is, for example, a light intensity distribution (for example, a light intensity distribution along the longitudinal direction of light). Also good. In this case, the state estimation unit 64 performs image analysis on the imaging data acquired by the observation unit 63, specifies the intensity distribution along the longitudinal direction of the observation light L2 on the observation target surface 630, and specifies the specified intensity distribution. Is estimated as the intensity distribution along the long-width direction of the drawing light L1 on the modulation surface 820.

  When the drawing focus lens 814 is disposed at the reference position, the observation light L2 incident on the observation target surface 630 and the drawing light L1 incident on the modulation surface 820 have the same history. That is, the drawing light L1 and the observation light L2 branched by the branching unit 61 travel the same optical distance, enter the drawing focus lens 814 or the observation focus lens 62, and further have the same optical distance. Then, the light is converged to the modulation surface 820 or the observation target surface 630. Therefore, the actual state of the light on the modulation surface 820 matches the light state on the observation target surface 630 with high accuracy. That is, the state of light estimated by the state estimation unit 64 (particularly, the state of light that changes depending on the optical distance) is reliable information that accurately matches the actual state of light on the modulation surface 820. I can say that.

  For example, when the light emitted from the light source unit 81 fluctuates, the fluctuation amount changes depending on the optical distance. Here, the optical distance from the light source unit 81 to the observation target surface 630, and the light source unit Since the optical distance from 81 to the modulation surface 820 is equal, the actual incident position of light on the modulation surface 820 matches the incident position of light on the observation target surface 630 with high accuracy. That is, it can be said that the estimated incident position acquired by the state estimating unit 64 is reliable information that accurately matches the actual incident position of light on the modulation surface 820.

<3. Correction unit 70>
Based on the estimated incident position acquired by the state estimation unit 64, the exposure unit 8 is an optical path along which the light emitted from the light source unit 81 travels (specifically, the light is emitted from the light source unit 81 and transmitted through the branch unit 61). A correction unit 70 that adjusts the relative positional relationship between the optical path of the drawing light L1) and the modulation surface 820 is provided.

  The correction unit 70 will be specifically described with reference to FIG. The correcting unit 70 changes the relative positional relationship between the optical path of the drawing light L1 and the modulation surface 820 by displacing the drawing focus lens 814. The correction unit 70 includes a lens displacement mechanism 71 and a change control unit 72.

<Lens displacement mechanism 71>
The lens displacement mechanism 71 moves the drawing focus lens 814 along the Z axis (that is, in a plane orthogonal to the optical axis of the drawing light L1 (in the XZ plane), and a direction orthogonal to the sub-scanning direction (X direction). And the position (height position) along the Z direction of the drawing focus lens 814 is changed.

  The lens displacement mechanism 71 will be specifically described with reference to FIG. FIG. 6 is a diagram schematically showing the lens displacement mechanism 71.

  The lens displacement mechanism 71 includes a gate-shaped frame 711 fixed to the base 710 and the like, and a floating holder 712 supported by the frame 711. The floating holder 712 holds the outer edge of the drawing focus lens 814.

  On the inner wall surface of one side wall of the frame 711, a fixing restricting pin 713 is provided so as to abut on the one side frame of the floating holder 712. On the other hand, a spring 714 is disposed in a contracted state between the inner wall surface of the other side wall of the frame 711 and the other side frame of the floating holder 712. Therefore, the floating holder 712 receives the biasing force of the spring 714 and is pressed against the fixing restricting pin 713, whereby the floating holder 712 is positioned in the horizontal direction (X-axis direction) (as a result, the drawing focus lens 814. Are controlled).

  On the other hand, the top plate of the frame 711 is formed with, for example, two through holes 7111 penetrating up and down at an interval in the X direction, and the movable restriction pin 715 can be moved up and down in each through hole. It is inserted in the state. Each movable restriction pin 715 is sufficiently longer than the thickness of the top plate of the frame 711, and the lower end of the movable restriction pin 715 comes into contact with the upper frame of the floating holder 712. On the other hand, between the base 710 and the lower frame of the floating holder 712, a contracted spring 716 is disposed at each position facing the movable restricting pin 715. Therefore, the floating holder 712 receives the biasing force of the spring 716 and is pressed against the movable restricting pin 715, whereby the floating holder 712 is positioned in the vertical direction (Z-axis direction) (as a result, the drawing focus lens). 814 position) is regulated.

  Here, at the upper end of each movable restriction pin 715, a drive unit 717 for changing the height position (position along the Z direction) of the movable restriction pin 715 is disposed. Specifically, the drive unit 717 can be configured to include, for example, a direct-acting actuator driven by a stepping motor or a servo motor. When the drive unit 717 moves the movable restricting pin 715 up and down, the floating holder 712 (and thus the drawing focus lens 814) is displaced up and down accordingly. However, the drive unit 717 is electrically connected to the control unit 9 (specifically, the change control unit 72 realized by the control unit 9), and operates under the control of the change control unit 72. That is, the height position of the drawing focus lens 814 is controlled by the change control unit 72.

  When the drawing focus lens 814 is displaced along the Z axis, the relative positional relationship between the optical path of the drawing light L1 and the modulation surface 820 is changed, and the incident position of the drawing light L1 on the modulation surface 820 is changed. Is done. For example, when the optical path of the drawing light L1 as illustrated is formed, when the drawing focus lens 814 is displaced upward from the reference position, the actual incident position of the drawing light L1 on the modulation surface 820 is The position corresponding to the displacement amount of the drawing focus lens 814 is the position on the + Y side from the estimated incident position. When the drawing focus lens 814 is displaced downward from the reference position, the actual incident position of the drawing light L1 on the modulation surface 820 is an estimated incident position corresponding to the amount of displacement of the drawing focus lens 814. The position is on the -Y side.

<Change control unit 72>
Based on the estimated incident position acquired by the state estimating unit 64, the change control unit 72 causes the actual incident position of the drawing light L1 on the modulation surface 820 to approach the ideal position (for example, the center line of the modulation surface 820). The displacement direction and displacement amount of the drawing focus lens 814 are specified (preferably so as to coincide with the ideal position). Then, the change control unit 72 controls the lens displacement mechanism 71 to displace the drawing focus lens 814 in the specified displacement direction by the specified displacement amount.

  For example, in the case where the optical path of the drawing light L1 as illustrated is formed, when the estimated incident position is on the −Y side from the ideal position, the change control unit 72 controls the lens displacement mechanism 71. Then, the drawing focus lens 814 is displaced upward from the reference position. As a result, the actual incident position of the drawing light L1 on the modulation surface 820 becomes a position on the + Y side from the estimated incident position. That is, the deviation width from the ideal position of the actual incident position of the drawing light L1 is reduced. Conversely, when the estimated incident position is on the + Y side from the ideal position, the change control unit 72 controls the lens displacement mechanism 71 to displace the drawing focus lens 814 downward from the reference position. As a result, the actual incident position of the drawing light L1 on the modulation surface 820 becomes a position on the −Y side with respect to the estimated incident position. That is, the deviation width from the ideal position of the actual incident position of the drawing light L1 is reduced.

  The change control unit 72 may calculate any amount of displacement of the drawing focus lens 814. For example, the change control unit 72 may use the displacement amount between the estimated incident position and the ideal position as the displacement amount of the drawing focus lens 814 as it is. For example, the change control unit 72 may use a distance corresponding to half the amount of deviation between the estimated incident position and the ideal position as the displacement amount of the drawing focus lens 814. Further, for example, the change control unit 72 is required for a predetermined time from the current time (for example, for the movement of the drawing focus lens 814 based on the estimated incident position at the current time acquired by the state estimating unit 64 and the past estimated incident position. It is also possible to predict an estimated incident position at a time earlier by (time) and use a displacement amount between the predicted estimated incident position and the ideal position as a displacement amount of the drawing focus lens 814. Further, the change control unit 72 may set the displacement amount to zero when the deviation amount between the estimated incident position and the ideal position is equal to or less than a predetermined allowable range.

<4. Flow of processing performed by monitoring unit 60 and correction unit 70>
The flow of processing performed by the monitoring unit 60 and the correction unit 70 will be described with reference to FIG.

  When the emission of light from the light source unit 81 is started, the monitoring unit 60 starts monitoring the light state on the modulation surface 820. Specifically, the branching unit 61 branches a part of the light L emitted from the light source unit 81, and the observation focus lens 62 converts the branched light (observation light L2) into the observation target surface 630. To converge. On the other hand, the observation unit 63 acquires the imaging data of the observation target surface 630 continuously (or intermittently at a predetermined period). When the imaging data is acquired, the state estimation unit 64 performs image analysis on the imaging data, identifies the incident position of the observation light L2 on the observation target surface 630, and determines the identified incident position as the modulation surface 820. Is obtained as the estimated incident position of the drawing light L1. In this way, the estimated incident position of the drawing light L1 on the modulation surface 820 is immediately acquired.

  On the other hand, in parallel with the monitoring unit 60 monitoring the state of light on the modulation surface 820, the correction unit 70 determines the optical path and the modulation surface of the drawing light L1 based on the estimated incident position acquired by the monitoring unit 60. The relative positional relationship with 820 is adjusted. Specifically, based on the estimated incident position acquired by the state estimating unit 64, the change control unit 72 draws the drawing focus lens 814 such that the actual incident position of the drawing light L1 on the modulation surface 820 approaches the ideal position. Specify the displacement direction and displacement amount. Then, the lens displacement mechanism 71 displaces the drawing focus lens 814 in the specified direction by the specified displacement amount. This ensures that the drawing light L1 is always incident at an ideal position (at least a position that does not greatly deviate from the ideal position) in the modulation surface 820.

  When there is no correction by the correction unit 70, when the light emitted from the light source unit 81 fluctuates, the light is incident on the modulation surface 820 at a position deviated from the ideal position. Appears as a misalignment. For example, when the optical path of the drawing light L1 as shown in the figure is formed, the fluctuation in the Z-axis direction of the light emitted from the light source unit 81 is caused by the arrangement direction of the plurality of modulation units (X 3) appear in the direction orthogonal to (direction) (Y direction), and this shift in the modulation surface 820 appears as a shift in the Y direction of the irradiation position of the drawing light on the substrate W (virtual line in FIG. 3). reference). When correction by the correction unit 70 is performed, even if the light emitted from the light source unit 81 fluctuates, the incident position of the drawing light L1 on the modulation surface 820 does not greatly deviate from the ideal position. Therefore, the drawing light is always applied to the intended position on the substrate W. That is, a decrease in exposure position accuracy is suppressed.

<5. Operation of exposure apparatus 1>
A flow of a series of processes for the substrate W executed in the exposure apparatus 1 will be described with reference to FIG. FIG. 7 is a diagram showing the flow of the processing. A series of operations described below is performed under the control of the control unit 9.

  In the exposure apparatus 1, first, the transport apparatus 2 takes out one unprocessed substrate W from the cassette C placed on the cassette placing unit 17 and transfers it onto the stage 4 in the processing area 14 (step). S1). At this time, the transport apparatus 2 may transfer the substrate W onto the stage 4 via the pre-alignment unit 3 as necessary. That is, the transport device 2 once carries the unprocessed substrate W taken out from the cassette C into the pre-alignment unit 3 and unloads the substrate W after the pre-alignment process from the pre-alignment unit 3 as necessary. It may be transferred on the stage 4.

  When the substrate W is placed on the stage 4 and the stage 4 sucks and holds the substrate W, the stage drive mechanism 5 subsequently moves the stage 4 to a position below the mark imaging unit 7. When the stage 4 is disposed below the mark imaging unit 7, a process (alignment process) for precisely aligning the substrate W on the stage 4 so as to be at an appropriate position is performed (step S2). Specifically, first, the mark imaging unit 7 images the upper surface of the substrate W. Subsequently, the control unit 9 performs image analysis on the imaging data acquired by the mark imaging unit 7 and detects an alignment mark on the substrate W therefrom. When the alignment mark is detected, the control unit 9 calculates how much the substrate W on the stage 4 is displaced from a predetermined position based on the detected position. When the positional deviation amount of the substrate W is calculated, the stage driving mechanism 5 moves the stage 4 by the calculated deviation amount, and aligns the substrate W so as to be in a predetermined position.

  When the substrate W is aligned, a pattern drawing process is performed (step S3). The drawing process is performed by irradiating light (drawing light) spatially modulated toward the upper surface of the substrate W from each exposure head 80 while moving each exposure head 80 relative to the substrate W. Is called.

  The drawing process will be specifically described with reference to FIG. FIG. 8 is a diagram for explaining the drawing process.

  In the drawing process, the stage drive mechanism 5 first moves the stage 4 disposed below the mark imaging unit 7 in the forward direction (here, for example, in the + Y direction) along the main scanning axis (Y axis). As a result, the substrate W is moved relative to each exposure head 80 along the main scanning axis (outward main scanning). When viewed from the substrate W, each exposure head 80 crosses the substrate W in the −Y direction along the main scanning axis (arrow AR11). On the other hand, when main scanning is started, irradiation of drawing light from each exposure head 80 is started. That is, the control unit 9 stores the pattern data D (specifically, the part of the pattern data D stored in the storage device 94 that describes data to be drawn in the stripe area to be drawn in the main scanning). By reading and controlling the modulation unit 82 according to the read pattern data D, drawing light spatially modulated according to the pattern data D is emitted from the exposure heads 80 toward the substrate W. .

  When each exposure head 80 crosses the substrate W once along the main scanning axis while intermittently emitting drawing light toward the substrate W, one stripe region (extending along the main scanning axis) is obtained. The pattern group is drawn in a region where the width along the sub-scanning axis corresponds to the width of the drawing light. Here, since the two exposure heads 80 and 80 simultaneously traverse the substrate W, a pattern group is drawn in each of the two stripe regions by one forward main scan.

  When the forward main scanning with drawing light irradiation ends, the stage drive mechanism 5 corresponds to the width of the drawing light in a predetermined direction (for example, −X direction) along the sub-scanning axis (X axis). By moving the substrate by the distance, the substrate W is moved relative to each exposure head 80 along the sub-inspection axis (sub-scanning). When viewed from the substrate W, each exposure head 80 moves in the + X direction along the sub-scanning axis by the width of the stripe region (arrow AR12).

  When the sub-scanning is completed, a return main scanning with irradiation of drawing light is executed. That is, the stage drive mechanism 5 moves the stage 4 along the main scanning axis (Y axis) in the backward direction (here, the −Y direction), thereby moving the substrate W relative to each exposure head 80 to the main scanning axis. (Return main scanning). When viewed from the substrate W, each exposure head 80 moves across the substrate W in the + Y direction along the main scanning axis (arrow AR13). On the other hand, when the backward main scan is started, irradiation of the drawing light from each exposure head 80 is started. By this backward main scanning, a pattern group is drawn in the stripe area adjacent to the stripe area drawn in the previous forward main scanning.

  When the backward main scanning with the drawing light irradiation ends, the sub-scanning is performed, and then the forward main scanning with the drawing light irradiation is performed again. By the forward main scanning, a pattern group is drawn in the stripe area adjacent to the stripe area drawn in the previous backward main scanning. Thereafter, similarly, the main scanning with the irradiation of the drawing light is repeatedly performed with the sub-scan interposed therebetween, and the drawing process is completed when the pattern is drawn over the entire drawing target area.

  However, as described above, while the light is emitted from the light source unit 81, the monitoring unit 60 monitors the light state on the modulation surface 820, and in parallel with this, the correction unit 70 monitors the monitoring unit 60. The relative positional relationship between the optical path of the drawing light L1 and the modulation surface 820 is adjusted on the basis of the estimated incident position acquired. Thus, even if the light emitted from the light source unit 81 fluctuates, it is ensured that the exposure position accuracy is unlikely to deteriorate.

  Refer to FIG. 7 again. When the drawing process is completed, the transport apparatus 2 receives the processed substrate W from the stage 4 and stores it in the cassette C (step S4). Thus, a series of processes for the substrate W is completed. After the processed substrate W is accommodated in the cassette C, the transport apparatus 2 takes out a new unprocessed substrate W from the cassette C, and this time, the substrate W is subjected to the series of processes described above. become.

<6. Effect>
According to the above embodiment, it is possible to acquire imaging data of the light emitted from the light source unit 81 on the observation target surface 630. Here, since the optical distance from the light source unit 81 to the observation target surface 630 is equal to the optical distance from the light source unit 81 to the modulation surface 820, the state of light on the observation target surface 630 (in particular, the light depending on the optical distance). It can be estimated that the state is equal to the state of light on the modulation surface 820. Therefore, the state of light on the modulation surface 820 of the spatial light modulator 821 can be accurately grasped from the imaging data acquired by the observation unit 63.

  Further, according to the above-described embodiment, the state estimation unit 64 that estimates the light state on the modulation surface 820 based on the imaging data acquired by the observation unit 63 is provided. Therefore, for example, when there is an abnormality in the light state on the modulation surface 820, this can be quickly detected. In particular, according to the above embodiment, the state estimation unit 64 estimates the incident position of light on the modulation surface 820 based on the imaging data acquired by the observation unit 63. Therefore, for example, when the incident position of light on the modulation surface 820 deviates from the ideal position, this can be detected quickly.

  Further, according to the above-described embodiment, the correction unit 70 is based on the light incident position on the modulation surface 820 estimated by the state estimation unit 64, and the light path (light for drawing) travels from the light source unit 81. The relative positional relationship between the optical path L1) and the modulation surface 820 is adjusted. According to this configuration, for example, when the estimated incident position is deviated from the ideal position, the actual incident position of light on the modulation surface 820 can be brought closer to the ideal position by changing the relative positional relationship. . Thereby, it is possible to suppress a decrease in exposure position accuracy. Further, according to this configuration, the exposure apparatus 1 is not thermally stable, such as immediately after activation of the exposure apparatus 1 or after a long period of non-use state (that is, the light emitted from the light source unit 81 is not emitted). Even in a state in which the exposure apparatus tends to fluctuate), the exposure position accuracy is unlikely to deteriorate, so that it is not necessary to warm up the exposure apparatus 1. Therefore, a decrease in throughput of the exposure apparatus 1 can be suppressed.

  Further, according to the above-described embodiment, the relative position relationship between the optical path in which the light emitted from the light source unit 81 travels and the modulation surface 820 is changed by displacing the drawing focus lens 814. According to this configuration, the actual incident position of light on the modulation surface 820 can be changed with a simple configuration.

  Further, according to the above embodiment, the optical distance between the observation focus lens 62 that converges light on the observation target surface 630 and the light source unit 81 is such that the drawing focus lens 814 that converges light on the modulation surface 820 and The optical distance to the light source unit 81 is equal. According to this configuration, the history of light emitted from the light source unit 81 and incident on the observation target surface 630 is equal to the history of light emitted from the light source unit 81 and incident on the modulation surface 820. Therefore, the state of light on the modulation surface 820 of the spatial light modulator 821 can be estimated particularly accurately from the imaging data acquired by the observation unit 63.

<7. Modification>
In the above embodiment, the correction unit 70 changes the relative positional relationship between the optical path of the drawing light L1 and the modulation surface 820 by displacing the drawing focus lens 814. May change this relative positional relationship in another manner. For example, the correction unit 70 may change the relative positional relationship by moving the spatial light modulator 821 in a direction orthogonal to the arrangement direction (X direction) of a plurality of modulation units.

  In the above embodiment, the correction unit 70 is not always necessary. For example, instead of the correction unit 70, when the estimated incident position acquired by the state estimation unit 64 exceeds a predetermined allowable range, a notification unit that notifies the operator to that effect may be provided.

  In the above embodiment, the estimated incident position acquired by the state estimating unit 64 is used for correcting the incident position of the drawing light L1 on the modulation surface 820. However, the estimated incident position acquired by the state estimating unit 64 is used. The position may be used for various other controls. For example, when a problem occurs in the exposure head 80, the estimated incident position acquired by the state estimation unit 64 may be used to identify the location that caused the problem. Specifically, for example, in a situation where a defect occurs in the exposure head 80 and the drawing light is irradiated to a position shifted from the intended position on the substrate W, and the estimated incident position is not shifted from the ideal position. Therefore, it can be determined that the defective portion is located on the downstream side of the optical path of the drawing light L1 or the spatial light modulator 821.

  In the above embodiment, a diffraction grating type spatial light modulator is used as the spatial light modulator 821. However, the configuration of the spatial light modulator 821 is not limited to this. For example, a spatial light modulator in which modulation units such as mirrors are arranged one-dimensionally or two-dimensionally may be used. Specifically, for example, a DMD (Digital Micromirror Device) may be used.

  In the above embodiment, the substrate W to be processed is a semiconductor substrate, but other various substrates (for example, a printed circuit board, a substrate for a color filter provided in a liquid crystal display device, a liquid crystal display). A flat panel display (FPD) glass substrate such as a display device or a plasma display device) may be a processing target.

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 2 Conveyance apparatus 3 Pre-alignment part 4 Stage 5 Stage drive mechanism 6 Stage position measurement part 7 Mark imaging unit 8 Exposure unit 81 Light source part 814 Drawing focus lens 82 Modulation unit 821 Spatial light modulator 820 Modulation surface 83 Projection optics System 9 Control unit 60 Monitoring unit 61 Branching unit 62 Observation focus lens 63 Observation unit 630 Observation target surface 64 State estimation unit 70 Correction unit 71 Lens displacement mechanism 72 Change control unit W substrate

Claims (6)

An exposure apparatus that exposes the substrate by irradiating the substrate with spatially modulated light,
A holding unit for holding the substrate;
An optical device for forming spatially modulated light;
With
The optical device is
A light source that emits light;
An observation unit that receives a part of the light emitted from the light source unit through the observation target surface and acquires imaging data of the observation target surface;
A spatial light modulator that receives the remainder of the light emitted from the light source unit by a modulation surface and applies spatial modulation according to pattern data to the received light;
Based on the imaging data acquired by the observation unit, a state estimation unit that identifies a light state on the observation target surface and estimates the identified light state as a light state on the modulation surface;
With
The optical distance from the light source unit to the observation target surface is equal to the optical distance from the light source unit to the modulation surface,
Exposure device. The exposure apparatus according to claim 1 ,
The state estimation unit
Based on the imaging data acquired by the observation unit, identify the incident position of light on the observation target surface, and estimate the incident position of the identified light as the incident position of light on the modulation surface,
Exposure device. The exposure apparatus according to claim 2 ,
A correction unit that adjusts a relative positional relationship between an optical path traveled by light emitted from the light source unit and the modulation surface based on an incident position of light on the modulation surface estimated by the state estimation unit;
An exposure apparatus comprising: The exposure apparatus according to claim 3 ,
The optical device is
A first lens that converges the light emitted from the light source unit on the modulation surface;
With
The correction unit is
Changing the relative positional relationship by displacing the first lens;
Exposure device. The exposure apparatus according to claim 4 ,
The optical device is
A second lens that converges the light emitted from the light source unit onto the observation target surface;
With
An optical distance from the light source unit to the first lens is equal to an optical distance from the light source unit to the second lens;
Exposure device. An optical device for forming spatially modulated light,
A light source that emits light;
An observation unit that receives a part of the light emitted from the light source unit through the observation target surface and acquires imaging data of the observation target surface;
A spatial light modulator that receives the remainder of the light emitted from the light source unit by a modulation surface and applies spatial modulation according to pattern data to the received light;
Based on the imaging data acquired by the observation unit, a state estimation unit that identifies a light state on the observation target surface and estimates the identified light state as a light state on the modulation surface;
With
The optical distance from the light source unit to the observation target surface is equal to the optical distance from the light source unit to the modulation surface,
Optical device.

Images