JP2014107473A - Exposure device, and exposure method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To expose a substrate W appropriately by controlling the laser light incident position of a spatial light modulator 41 and the laser light irradiation position of the substrate W accurately, regardless of temperature variation of atmosphere.SOLUTION: Even if temperature variation of atmosphere occurs in an illumination system S5, incident position of light to a spatial light modulator 41 can be adjusted accurately, by detecting variation of the optical path due to temperature variation, and then correcting the optical path on the basis of the detection results. Even if temperature variation of atmosphere occurs in a projection system S4, the laser light irradiation position of the substrate W can be adjusted accurately, by detecting variation of the optical path due to temperature variation, and then correcting the optical path on the basis of the detection results.

Description

  The present invention relates to an exposure technique for exposing an exposure target by irradiating the exposure target with light modulated by a spatial light modulator.

  2. Description of the Related Art Conventionally, an exposure apparatus that irradiates an exposure target with light emitted from a light source in a pattern and forms a pattern on the exposure target is known. For example, in the exposure apparatus (pattern drawing apparatus) of Patent Document 1, light emitted from a light source composed of a laser drive unit and a laser oscillator is irradiated to an exposure target (substrate) through a mask. The mask has a light projecting portion having a shape corresponding to the pattern, and the light that has passed through the light projecting portion is irradiated onto the exposure target in a pattern, whereby a pattern is formed on the exposure target.

  In such an exposure apparatus, when a temperature change occurs in the atmosphere through which the optical path passes, the optical path may fluctuate, and light may not be irradiated to a desired position to be exposed. On the other hand, in patent document 1, the temperature change of an atmosphere is suppressed by adjusting the timing which operates heat sources, such as a motor, and the irradiation position of the light to exposure object is stabilized.

JP 2009-288740 A

  By the way, instead of the mask as described above, for example, a spatial light modulator constituted by GLV (Grating Light Valve (registered trademark)) or the like can be used to irradiate the exposure target with light in a pattern. In other words, the spatial light modulator modulates the emitted light according to the pattern and emits the light. By irradiating the exposure target with the light modulated by the spatial light modulator, the light is patterned into the exposure target. Can be irradiated.

  However, in order to appropriately expose the substrate using the spatial light modulator, it is required to accurately control both the light incident position on the spatial light modulator and the light irradiation position on the exposure target. In other words, if the incident position of light on the spatial light modulator fluctuates, the intensity of light modulated by the spatial light modulator may fluctuate, and as a result, the intensity of light that exposes the exposure target may not be appropriately controlled. There is. Further, when the irradiation position of the light modulated by the spatial light modulator to the exposure target fluctuates, it becomes impossible to irradiate the desired position of the exposure target with light.

  On the other hand, since the temperature change of the atmosphere described above can occur in any place, the optical path can be changed due to the temperature change of the atmosphere both before and after the spatial light modulator in the optical path. When the optical path variation occurs in front of the spatial light modulator, the intensity of light irradiated to the exposure target varies, and when the optical path variation occurs after the spatial light modulator, the position of the light irradiated to the exposure target. In any case, the exposure target may not be properly exposed.

  The present invention has been made in view of the above problems, and accurately controls the light incident position on the spatial light modulator and the light irradiation position on the exposure target regardless of the temperature change of the atmosphere. An object of the present invention is to provide a technique capable of realizing appropriate exposure.

  In order to achieve the above object, an exposure apparatus according to the present invention includes: a light source that emits light; and a spatial light modulator that emits modulated light emitted to an exposure target by modulating light emitted from the light source. An illumination optical path control means for adjusting the incident position of the light to the spatial light modulator by correcting the optical path in the illumination system based on the result of detecting the light traveling through the illumination system from the light source to the spatial light modulator And a projection optical path control means for adjusting the light irradiation position on the exposure target by correcting the optical path in the projection system based on the result of detecting the light traveling through the projection system reaching the exposure target from the spatial light modulator It is characterized by comprising.

  In order to achieve the above object, an exposure method according to the present invention exposes an exposure object by irradiating the exposure object with modulated light obtained by modulating light emitted from a light source with a spatial light modulator. Adjusting a light incident position on the spatial light modulator by correcting a light path in the illumination system based on a result of detecting light traveling through the illumination system from the light source to the spatial light modulator. Adjusting the light irradiation position on the exposure target by correcting the optical path in the projection system based on the result of detecting the light traveling through the projection system from the spatial light modulator to the exposure target. It is characterized by that.

  The invention thus configured (exposure apparatus, exposure method) corrects the light path in the illumination system based on the result of detecting the light that travels through the illumination system from the light source to the spatial light modulator. Adjust the position of light incident on the modulator. Therefore, even if an ambient temperature change occurs before the spatial light modulator (that is, the illumination system), a change in the optical path due to the temperature change is detected, and the optical path is corrected based on the detection result. The light incident position on the spatial light modulator can be adjusted accurately. Further, the irradiation position of the light to the exposure target is adjusted by correcting the optical path in the projection system based on the result of detecting the light traveling through the projection system reaching the exposure target from the spatial light modulator. Therefore, even if the ambient temperature changes after the spatial light modulator (that is, the projection system), the variation in the optical path due to the temperature change is detected, and the optical path is corrected based on the detection result. Thus, the light irradiation position on the exposure target can be adjusted accurately. Thus, according to the present invention, appropriate exposure of the exposure target is realized by accurately controlling the light incident position on the spatial light modulator and the light irradiation position on the exposure target regardless of the temperature change of the atmosphere. Is possible.

  The illumination optical path control means includes an illumination optical path detector that detects the position of light passing through the illumination optical path detection location in the illumination system, and an illumination optical path that corrects the optical path of light passing through the illumination optical path correction location in the illumination system. The exposure apparatus may be configured to adjust the incident position of the light to the spatial light modulator by controlling the illumination optical path corrector based on the detection result of the illumination optical path detector. good. In such a configuration, by detecting the position of the light passing through the illumination optical path detection location, it is possible to detect a change in the optical path caused by a temperature change. Then, by correcting the optical path of the light passing through the illumination optical path correction location based on the detection result, it is possible to accurately adjust the incident position of the light to the spatial light modulator.

  Further, the illumination optical path detector detects the position of the light at each of the plurality of illumination optical path detection points, and the illumination optical path corrector corrects the optical path of the light passing through each of the plurality of illumination optical path correction points, An exposure apparatus may be configured. By providing a plurality of illumination light path detection points and illumination light path correction points in this manner, the light incident position on the spatial light modulator can be controlled with higher accuracy.

  Specifically, the illumination optical path control means is configured to detect the position of light at each of the plurality of illumination optical path detection points by the illumination optical path detector at each of the plurality of illumination optical path correction points by the illumination light path correction unit. By controlling the correction of the optical path, the position of the optical path in the direction orthogonal to the optical axis of the illumination system and the angle of the optical path with respect to the optical axis of the illumination system are adjusted to adjust the incident position of the light to the spatial light modulator. Thus, an exposure apparatus may be configured. Such a configuration can optimize the position and angle of the optical path, and is suitable for controlling the incident position of light on the spatial light modulator with high accuracy.

  Further, the projection optical path control means includes a projection optical path detector for detecting the position of light passing through the projection optical path detection location in the projection system, and a projection optical path for correcting the optical path of light passing through the projection optical path correction location in the projection system. The exposure apparatus may be configured to adjust the irradiation position of the light to the exposure target by controlling the projection optical path corrector based on the detection result of the projection optical path detector. In such a configuration, by detecting the position of the light passing through the projection optical path detection location, it is possible to detect a change in the optical path due to a temperature change. Then, by correcting the optical path of the light passing through the projection optical path correction location based on the detection result, it is possible to accurately adjust the light irradiation position on the exposure target.

  Further, the projection optical path detector detects the position of the light at each of the plurality of projection optical path detection points, and the projection optical path corrector corrects the optical path of the light passing through each of the plurality of projection optical path correction points, An exposure apparatus may be configured. By providing a plurality of projection optical path detection points and projection optical path correction points in this way, it becomes possible to control the irradiation position of light to the exposure target with higher accuracy.

  Specifically, the projection optical path control means is configured to detect the position of the light at each of the plurality of projection optical path detection points by the projection optical path detector at each of the plurality of projection optical path correction points by the projection optical path correction unit. By controlling the correction of the optical path, the position of the optical path in the direction orthogonal to the optical axis of the projection system and the angle of the optical path with respect to the optical axis of the projection system are adjusted to adjust the irradiation position of the light to the exposure target. An exposure apparatus may be configured. Such a configuration can optimize the position and angle of the optical path, and is suitable for controlling the irradiation position of the light to the exposure target with high accuracy.

  According to the present invention, it is possible to appropriately control the exposure target by accurately controlling the light incident position on the spatial light modulator and the light irradiation position on the exposure target regardless of the temperature change of the atmosphere. .

It is a front view which shows typically schematic structure of the pattern drawing apparatus concerning this invention. It is a top view which shows typically schematic structure of the pattern drawing apparatus of FIG. It is a figure which shows typically an example of a structure with which a diffractive optical element is provided. It is a figure which shows typically the 1st structural example of an optical unit. It is a flowchart which shows an example of the operation | movement which performs optical path correction | amendment of a laser beam dynamically in parallel with pattern drawing. It is a block diagram which shows typically the structure which performs the flowchart of FIG. It is a figure which shows the example of the image of the laser beam which an optical sensor detects. It is a figure for demonstrating the calculation method of the position and angle of an optical path. It is a figure which shows the 2nd structural example of an optical unit typically. It is a figure which shows typically the 3rd structural example of an optical unit.

  FIG. 1 is a front view schematically showing a schematic configuration of a pattern drawing apparatus to which the present invention is applicable. FIG. 2 is a plan view schematically showing a schematic configuration of the pattern drawing apparatus of FIG. The pattern drawing 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 is formed. The substrate W may be any of various substrates such as a semiconductor substrate, a printed substrate, a color filter substrate, a glass substrate for a flat panel display provided in a liquid crystal display device or a plasma display device, and an optical disk substrate. In the illustrated example, the upper layer pattern is drawn so as to overlap the lower layer pattern formed on the upper surface of the circular semiconductor substrate.

  The pattern drawing apparatus 100 includes an inside of the main body formed by attaching cover panels (not shown) to the ceiling surface and the peripheral surface of the skeleton composed of the main body frame 101, and an outside of the main body that is outside the main body frame 101. The various components are arranged.

  The main body of the pattern drawing apparatus 100 is divided into a processing area 102 and a delivery area 103. Of these areas, the stage 10, the stage moving mechanism 20, the stage position measuring unit 30, the optical unit U, and the alignment unit 60 are mainly arranged in the processing area 102. On the other hand, in the transfer area 103, a transfer device 70 such as a transfer robot for transferring the substrate W to and from the processing area 102 is arranged.

  Further, an illumination unit 61 that supplies illumination light to the alignment unit 60 is disposed outside the main body of the pattern drawing apparatus 100. In addition, the main body is provided with a control unit 90 that is electrically connected to each unit of the pattern drawing apparatus 100 and controls the operation of each unit.

  In addition, a cassette placement unit 104 for placing the cassette C is disposed outside the main body of the pattern drawing apparatus 100 at a position adjacent to the transfer area 103. Further, the transfer device 70 corresponding to the cassette placement unit 104 and disposed in the transfer area 103 inside the main body takes out the unprocessed substrate W accommodated in the cassette C placed on the cassette placement unit 104. The substrate W is loaded into the processing region 102 (loading), and the substrate W is unloaded from the processing region 102 and is stored in the cassette C. Delivery of the cassette C to the cassette mounting unit 104 is performed by an external transport device (not shown). The loading process of the unprocessed substrate W and the unloading process of the processed substrate W are performed by operating the transfer device 70 in accordance with an instruction from the control unit 90.

  The stage 10 has a flat outer shape, and is a holding unit that places and holds the substrate W in a horizontal posture on the upper surface thereof. A plurality of suction holes (not shown) are formed on the upper surface of the stage 10, and by applying a negative pressure (suction pressure) to the suction holes, the substrate W placed on the stage 10 is placed on the stage 10. It can be fixedly held on the upper surface of the. Then, the stage 10 is moved by the stage moving mechanism 20.

  The stage moving mechanism 20 is a mechanism that moves the stage 10 in the main scanning direction (Y-axis direction), the sub-scanning direction (X-axis direction), and the rotation direction (rotation direction around the Z axis (θ-axis direction)). The stage moving mechanism 20 includes a base plate 24 that supports a support plate 22 that rotatably supports the stage 10, a sub-scanning mechanism 23 that moves the support plate 22 in the sub-scanning direction, and a main plate that moves the base plate 24 in the main scanning direction. And a scanning mechanism 25. The sub scanning mechanism 23 and the main scanning mechanism 25 move the stage 10 in accordance with an instruction from the control unit 90.

  The sub-scanning mechanism 23 includes a linear motor 23 a configured by a moving element (not shown) attached to the lower surface of the support plate 22 and a stator (not shown) laid on the upper surface of the base plate 24. In addition, a pair of guide portions 23 b extending in the sub-scanning direction is provided between the support plate 22 and the base plate 24. For this reason, when the linear motor 23 a is operated, the support plate 22 moves in the sub-scanning direction X along the guide portion 23 b on the base plate 24.

  The main scanning mechanism 25 has a linear motor 25 a composed of a mover attached to the lower surface of the base plate 24 and a stator laid on the base 106 of the pattern drawing apparatus 100. A pair of guide portions 25b extending in the main scanning direction is provided between the base plate 24 and the base 106. Therefore, when the linear motor 25 a is operated, the base plate 24 moves in the main scanning direction Y along the guide portion 25 b on the base 106.

  The stage position measurement unit 30 is a mechanism that measures the position of the stage 10. The stage position measurement unit 30 is electrically connected to the control unit 90 and measures the position of the stage 10 in accordance with an instruction from the control unit 90. The stage position measurement unit 30 is configured by a mechanism that irradiates a laser beam toward the stage 10 and measures the position of the stage 10 by using interference between the reflected light and the emitted light, for example. The operation is not limited to this. Here, the stage position measurement unit 30 includes an emission unit 31 that emits laser light, a beam splitter 32, a beam bender 33, a first interferometer 34, and a second interferometer 35. The emission unit 31 and the interferometers 34 and 35 are electrically connected to the control unit 90 and measure the position of the stage 10 in accordance with an instruction from the control unit 90.

  The laser light emitted from the emission unit 31 first enters the beam splitter 32 and is branched into first branched light that goes to the beam bender 33 and second branched light that goes to the second interferometer 35. The first branched light is reflected by the beam bender 33, enters the first interferometer 34, and is irradiated from the first interferometer 34 to the first portion of the stage 10. Then, the first branched light reflected by the first part is incident on the first interferometer 34 again. The first interferometer 34 is a positional parameter corresponding to the position of the first part based on the interference between the first branched light traveling toward the first part of the stage 10 and the first branched light reflected by the first part. Measure.

  On the other hand, the second branched light is incident on the second interferometer 35 and the second part of the stage 10 from the second interferometer 35 (however, the second part is a position different from the first part. .). Then, the second branched light reflected by the second part is incident on the second interferometer 35 again. The second interferometer 35 corresponds to the position of the second part based on the interference between the second branched light traveling toward the second part of the stage 10 and the second branched light reflected by the second part of the stage 10. The measured position parameter is measured.

  The control unit 90 obtains a position parameter corresponding to the position of the first part of the stage 10 and a position parameter corresponding to the position of the second part of the stage 10 from each of the first interferometer 34 and the second interferometer 35. get. Then, the position of the stage 10 is calculated based on each acquired position parameter.

  The alignment unit 60 images an alignment mark (not shown) formed on the upper surface of the substrate W. The alignment unit 60 includes an alignment camera 601 having a lens barrel, an objective lens, and a CCD image sensor. The CCD image sensor provided in the alignment camera 601 is constituted by, for example, an area image sensor (two-dimensional image sensor). The alignment unit 60 is supported by a lifting mechanism (not shown) so as to be lifted and lowered within a predetermined range.

  The illumination unit 61 is connected to the lens barrel via the fiber 601 and supplies illumination light to the alignment unit 60. The light guided by the fiber 601 extending from the illumination unit 61 is guided to the upper surface of the substrate W through the lens barrel of the alignment camera 601, and the reflected light is received by the CCD image sensor through the objective lens. As a result, the upper surface of the substrate W is imaged and image data is acquired. The alignment camera 601 is electrically connected to the image processing unit of the control unit 90, acquires imaging data in accordance with an instruction from the control unit 90, and transmits the acquired imaging data to the control unit 90.

  Based on the imaging data provided from the alignment camera 601, the control unit 90 performs an alignment process of detecting a reference mark provided at the reference position of the substrate W and positioning the relative position between the optical unit U and the substrate W. Then, pattern drawing is performed by irradiating a predetermined position of the substrate W with laser light modulated according to the drawing pattern from the optical unit U.

  The optical unit U has a schematic configuration in which two optical heads 4 that modulate laser light based on strip data corresponding to a drawing pattern are arranged along the X-axis direction. The number of optical heads 4 is not limited to this. Since these optical heads 4 have the same configuration, the configuration related to one optical head 4 will be described below.

  The optical unit U is provided with a light irradiation unit 5 that irradiates the optical head 4 with laser light. The light irradiation unit 5 includes a laser driving unit 51, a laser oscillator 52, and an illumination optical system 53. Then, the laser beam emitted from the laser oscillator 52 by the operation of the laser driving unit 51 enters the optical head 4 through the illumination optical system 53. In the optical head 4, the laser light irradiated from the light irradiation unit 5 is modulated by the spatial light modulator and irradiated onto the substrate W via the projection optical system 43. Thus, the upper layer pattern (drawing pattern) is overlaid and exposed on the lower layer pattern formed on the unprocessed substrate W.

  Note that the spatial light modulator of the optical head 4 modulates laser light using a diffractive optical element 410 having a configuration similar to, for example, GLV described in Japanese Patent Laid-Open No. 2012-169549 (FIG. 3). Here, FIG. 3 is a diagram schematically illustrating an example of the configuration of the diffractive optical element. The diffractive optical element 410 can be in an OFF state and an ON state. In the figure, the diffractive optical element 410 in the OFF state is shown in the upper column, and the diffractive optical element 410 in the ON state is shown in the lower column. ing.

  As shown in FIG. 3, the diffractive optical element 410 has a fixed ribbon 412 (fixed member) and a movable ribbon 413 (movable member) opposed to the surface of a flat bottom electrode 411 (reference electrode) and parallel to the surface. It has a schematic configuration that is alternately arranged in various directions. The fixed ribbon 412 and the movable ribbon 413 have reflection surfaces 412s and 413s that are finished into a flat surface and reflect light. The fixed ribbon 412 is fixed to the bottom electrode 411 at a predetermined interval, while the movable ribbon 413 is provided so as to be movable with respect to the bottom electrode 411. In the OFF state of the diffractive optical element 410, the movable ribbon 413 is separated from the bottom electrode 411, and the reflective surface 412s of the fixed ribbon 412 and the reflective surface 413s of the movable ribbon 413 are flush with each other. On the other hand, in the ON state of the diffractive optical element 410, the movable ribbon 413 approaches the bottom electrode 411, and a step is generated between the reflective surface 412 s of the fixed ribbon 412 and the reflective surface 413 s of the movable ribbon 413.

  The operation of the movable ribbon 413 is controlled by applying a voltage to the movable ribbon 413. That is, when a printing voltage is applied to the movable ribbon 413, an electrostatic force corresponding to the potential difference between the movable ribbon 413 and the bottom electrode 411 acts on the movable ribbon 413. This electrostatic force attracts the movable ribbon 413 to the bottom electrode 411 while deforming the movable ribbon 413 against the mechanical elastic force of the movable ribbon 413. As a result, the movable ribbon 413 is displaced toward the bottom electrode 411 with respect to the fixed ribbon 412, and the ON state shown in FIG. 3 is realized. On the other hand, when the application of voltage to the movable ribbon 413 is stopped, the electrostatic force between the movable ribbon 413 and the bottom electrode 411 disappears, so that the movable ribbon 413 is displaced to a position aligned with the fixed ribbon 412 by the elastic force. Thus, the OFF state shown in FIG. 3 is realized.

  In the OFF state, the reflecting surfaces 412 s and 413 s of the ribbons 412 and 413 are aligned, so that the incident light Li to the diffractive optical element 410 is regularly reflected by the reflecting surfaces 412 s and 413 s and is reflected from the diffractive optical element 410. Emits 0th-order diffracted light (regularly reflected light) Lo. On the other hand, in the ON state, a step is generated between the reflecting surfaces 412 s and 413 s of the ribbons 412 and 413, so that an optical path difference is generated between the reflected light on the reflecting surface 412 s and the reflected light on the reflecting surface 413 s. As a result, a diffraction grating is formed by the adjacent fixed ribbon 412 and movable ribbon 413, and first-order or higher-order diffracted light Lg is emitted from the diffractive optical element 410. At this time, the movable ribbon 413 stops at a position where the electrostatic force and the elastic force are balanced. Therefore, by controlling the value of the voltage applied to the movable ribbon 413, the position of the movable ribbon 413 (in other words, the depth of the diffraction grating) is changed, and the amount of specularly reflected light (0th order diffraction) from the diffractive optical element 410 is changed. Light quantity) can be adjusted.

  Such control is executed in units of pixels. For example, three fixed ribbons 412 and three movable ribbons 413 arranged adjacent to each other constitute one pixel, and the voltage applied to the movable ribbon 413 is controlled in units of one pixel. As a result, the adjustment of the regular reflection light amount (0th-order diffracted light amount) is executed in units of one pixel.

  Incidentally, the amount of laser light emitted from the laser oscillator 52 is not always uniform and may have a slight distribution. Therefore, by giving an offset to the movable ribbon 413 (specifically, by applying an offset voltage) so as to cancel the light quantity distribution of the laser light emitted from the laser oscillator 52, data to the spatial light modulator is obtained. Initial setting is performed so that the amount of laser light emitted from the diffractive optical element 410 is uniform in a state where no (drawing data) is input. Specifically, an initial setting value indicating a voltage applied to the movable ribbon 413 in the initial setting is stored in the control unit 90. Then, the control unit 90 applies an offset voltage (DC voltage) indicated by the initial setting value to the movable ribbon 413. Therefore, when the movable ribbon 413 is driven based on the data, an applied voltage obtained by adding a voltage (AC voltage) modulated according to the data and the offset voltage is applied to the movable ribbon 413.

  As described above, in the optical unit U, the laser light emitted from the light source (hereinafter, appropriately referred to as the light sources 51 and 52) including the laser driving unit 51 and the laser oscillator 52 is modulated by the diffractive optical element 410. Then, the laser beam modulated by the diffractive optical element 410 is irradiated onto the substrate W to be exposed. Next, a specific configuration example of such an optical unit U will be described in detail.

A. First Configuration Example of Optical Unit FIG. 4 is a diagram schematically illustrating a first configuration example of the optical unit. As shown in FIG. 4, the optical unit U is provided with a spatial light modulator 41 having a diffractive optical element 410. The configuration of the optical unit U is roughly divided into an illumination system S5 from the light sources 51 and 52 to the diffractive optical element 410 and a projection system S4 from the diffractive optical element 410 to the substrate W.

  In the illumination system S5, the lenses 53a and 53b functioning as expanders that expand the laser light emitted from the light sources 51 and 52, the lens 53c that converges the laser light emitted from the lenses 53a and 53b, and the lens 53c. A reflection mirror 42 that reflects the laser beam and guides it to the diffractive optical element 410 is disposed. The lenses 53a to 53c and the reflection mirror 42 constitute an illumination optical system 53 (FIG. 1).

  As shown in FIG. 4, collimated laser light (parallel light) travels in a section from the lens 53b to the lens 53c. The lens 53 c converges the laser light on the diffractive optical element 410, so that the laser light enters the diffractive optical element 410. As a result, a linear laser beam having a uniform intensity distribution (a laser beam having a linear beam cross section) is applied to the effective region of the diffractive optical element 410. Here, the effective region is a region where the diffractive optical element 410 can perform modulation on incident light.

  In the projection system S4, a lens 43b for collimating the laser light reflected by the diffractive optical element 410 and a lens 43d for converging the laser light emitted from the lens 43b are provided. Further, in the projection system S4, an aperture 43a disposed in a section from the diffractive optical element 410 to the lens 43b, and a stop 43c disposed in a section from the lens 43b to the lens 43d are provided. The aperture 43a, the aperture 43c, and the lenses 43b and 43d constitute the projection optical system 43 (FIG. 1).

  As shown in FIG. 4, the laser light reflected by the diffractive optical element 410 enters the lens 43b after unnecessary light is shielded by the aperture 43a. The aperture 43a cuts the laser beam in a direction perpendicular to the paper surface of FIG. 4. Among the laser beams reflected by the diffractive optical element 410, only the 0th-order diffracted light is allowed to pass, and first-order or higher-order diffracted light is passed. Takes the function of blocking. Therefore, only the 0th-order diffracted light is incident on the lens 43b, and the first-order or higher-order diffracted light is not incident. In the section from the lens 43b to the lens 43d, collimated laser light (parallel light) travels. The lens 43d converges the laser beam on the substrate W, so that the substrate W is irradiated with the laser beam. The projection system S4 may include a zoom mechanism.

  As can be seen from FIG. 4, the projection system S4 is configured such that the diffractive optical element 410 and the substrate W are optically conjugate. Therefore, an image of 0th-order diffracted light reflected from each pixel of the diffractive optical element 410 is projected onto the substrate W. Further, as described above, the amount of diffracted light from the diffractive optical element 410 can be adjusted by changing the depth of the diffraction grating by controlling the value of the voltage applied to the movable ribbon 413. Therefore, the control unit 90 can adjust the amount of laser light applied to the substrate W for each pixel by controlling the value of the voltage applied to the movable ribbon 413 for each pixel.

  By the way, in such an optical unit U, when the fluctuation of the optical path due to the temperature change occurs in the illumination system S5, the incident position of the laser light on the spatial light modulator 41 varies, and the modulated laser by the spatial light modulator 41 is changed. The intensity of the light may fluctuate, and as a result, the intensity of the laser light that exposes the substrate W may not be appropriately controlled. Various causes are conceivable depending on the situation. For example, the following may be mentioned.

  That is, in the above-described configuration in which the laser beam is focused on the effective region of the diffractive optical element 410, when the incident position of the laser beam is shifted with respect to the effective region of the diffractive optical element 410, the amount of laser light applied to the end of the effective region There is a possibility that a region that cannot be exposed with a sufficient amount of light may be generated on the substrate W due to a significant decrease. Alternatively, as described above, when the initial setting is performed so as to cancel the light amount distribution of the laser light from the light sources 51 and 52, if the position of the laser light incident on the spatial light modulator 41 varies, the initial setting The relationship between the adjusted light amount distribution and the offset of the movable ribbon 413 is destroyed, and the light amount of the laser light from the spatial light modulator 41 is inappropriately shifted.

  Such a problem of fluctuation of the optical path becomes a problem not only in the illumination system S5 but also in the projection system S4. That is, when the fluctuation of the optical path due to the temperature change occurs in the projection system S4, the irradiation position of the laser light modulated by the spatial light modulator 41 on the substrate W changes, and the laser light is moved to a desired position on the substrate W. Can no longer be irradiated.

  Therefore, in the illumination system S5 and the projection system S4, the optical path is stabilized regardless of the temperature change of each atmosphere (air), and the incident position of the laser light on the diffractive optical element 410 and the irradiation of the laser light on the substrate W are performed. It is required to control the position accurately. Therefore, each of the illumination system S5 and the projection system S4 of the optical unit U according to the first configuration example has the following configuration for correcting the optical path of the laser light.

  As shown in FIG. 4, a piezo mirror M is disposed at each of the locations P11 and P13 on the optical axis OA of the illumination system S5. The arrangement places P11 and P13 exist in the section from the lens 53b to the lens 53c, and the piezo mirror M at the arrangement place P11 directs the laser beam from the lens 53b toward the piezo mirror M at the arrangement place P13. The piezo mirror M at the location P13 reflects the laser light from the piezo mirror M at the location P11 toward the lens 53c. Then, by controlling the rotation of the piezo mirror M, it is possible to correct the optical path of the laser light at each of the arrangement places P11 and P13.

  The piezo mirror M is configured to drive a mirror using a piezo. For example, a mirror configured to be rotatable about two different axes is driven by the piezo to rotate around each axis. It has a configuration. A piezo mirror M to be described later has the same configuration.

  A beam splitter BS is disposed at each of the placement locations P12 and P14 on the optical axis OA of the illumination system S5. Further, a photosensor D is arranged to face each of the arrangement places P12 and P14. The beam splitter BS at the arrangement place P12 is arranged between the piezo mirrors M at the arrangement places P11 and P13, and transmits a part of the laser beam from the arrangement place P11 to the arrangement place P13, while the arrangement is made. Part of the laser beam from the installation location P11 is reflected to the optical sensor D facing the installation location P12. The beam splitter BS at the location P14 is disposed between the piezo mirror at the location P13 and the lens 53c, and transmits part of the laser light from the location P13 to the lens 53c. A part of the laser beam from P13 is reflected to the optical sensor D facing the arrangement place P14. The position where the light beam reaches each optical sensor D varies depending on the position of the light beam passing through the arrangement places P12 and P14. Accordingly, each optical sensor D detects the position of the laser beam passing through the corresponding arrangement locations P12 and P14.

  As the optical sensor D, a CCD (Charge Coupled Device) image sensor, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or a PSD (semiconductor position detector) can be used. The optical sensor D to be described later has the same configuration.

  Then, the control unit 90 controls the rotation of the piezo mirror M at each of the arrangement places P11 and P13 based on the result of obtaining the position of the laser beam passing through the arrangement places P12 and P14 from the detection result of the optical sensor D. To do. Thereby, the optical path of the laser beam of the illumination system S5 is corrected, and the incident position of the laser beam on the diffractive optical element 410 is adjusted.

  As shown in FIG. 4, a piezo mirror M is disposed at each of the locations P15 and P17 on the optical axis OA of the projection system S4. The arrangement place P15 exists in a section from the diffractive optical element 410 to the aperture 43a, and the piezo mirror M at the arrangement place P15 reflects the laser light from the diffractive optical element 410 toward the aperture 43a. Further, the arrangement place P17 exists in a section from the stop 43c to the lens 43d, and the piezo mirror M at the arrangement place P17 reflects the laser light from the stop 43c toward the lens 43d. Then, by controlling the rotation of the piezo mirror M, it is possible to correct the optical path of the laser beam at each of the arrangement locations P15 and P17.

  In addition, a beam splitter BS is arranged at each of the arrangement places P16 and P18 on the optical axis OA of the projection system S4. Further, the optical sensor D is arranged to face each of the arrangement places P16 and P18. The beam splitter BS at the location P16 is disposed between the piezo mirror M at the location P15 and the aperture 43a, and transmits part of the laser light from the location P15 to the aperture 43a. A part of the laser beam from the installation place P15 is reflected to the optical sensor D facing the installation place P16. The beam splitter BS at the location P18 is disposed between the piezo mirror M at the location P17 and the lens 43d, and transmits part of the laser light from the location P17 to the lens 43d. A part of the laser beam from the location P17 is reflected to the optical sensor D facing the location P18. The position where the light beam reaches each optical sensor D varies depending on the position of the light beam passing through the arrangement places P16 and P18. Accordingly, each optical sensor D detects the position of the laser light passing through the corresponding arrangement places P16 and P18.

  Then, the control unit 90 controls the rotation of the piezo mirror M at each of the arrangement places P15 and P17 based on the result of obtaining the position of the laser light passing through the arrangement places P16 and P18 from the detection result of the optical sensor D. To do. Thereby, the optical path of the laser beam of the projection system S4 is corrected, and the irradiation position of the laser beam on the substrate W is adjusted.

  As described above, it is possible to correct the optical path of the laser light based on the result of detecting the laser light in each of the illumination system S5 and the projection system S4. In this embodiment, appropriate pattern drawing on the substrate W can be executed by dynamically correcting the optical path of the laser beam while executing pattern drawing on the substrate W. Next, this point will be described in detail.

  FIG. 5 is a flowchart showing an example of an operation for dynamically performing optical path correction of laser light in parallel with pattern drawing. FIG. 6 is a block diagram schematically showing a configuration for executing the flowchart of FIG. That is, the flowchart of FIG. 5 is executed by the image acquisition unit 91, the image processing unit 93, the PID control unit 95, and the piezo drive unit 97 that are included in the control unit 90.

  Prior to the start of pattern drawing on the substrate W, the controller 90 sets the piezo drive amount of each piezo mirror M to an initial value (step S101). This initial value is obtained by exposing the exposure beam (laser) to appropriate positions on the spatial light modulator 41 (diffractive optical element 41) and the substrate W to be exposed when no fluctuation occurs in the illumination system S5 and the projection system S4. This is a value that realizes a state in which (light) is guided. Then, the piezo driving unit 97 drives the piezo PZ of each piezo mirror M according to the set initial value. As a result, the rotation amount of each piezo mirror M is optimized, and preparation for starting pattern drawing is completed. In the subsequent step S102, pattern drawing on the substrate W is started. Specifically, the control unit 90 applies an applied voltage corresponding to the drawing data corresponding to the drawing pattern to each movable ribbon 413 of the diffractive optical element 410, and the laser light modulated by the diffractive optical element 410 is applied to the substrate W. The pattern is drawn on the substrate W.

  Steps S103 to S109 are started with the start of pattern drawing in step S102 as a trigger. Note that the operations in steps S103 to S109 are performed independently in each of the illumination system S5 and the projection system S4. However, since the contents of the operations in the systems S5 and S4 are substantially the same, the operations in the illumination system S5 will be described in detail here, and the operations in the projection system S4 will be described later with a focus on the differences. .

  In step S103, the image acquisition unit 91 starts acquiring an image (FIG. 7) of the laser beam detected by each optical sensor D. Here, FIG. 7 is a diagram illustrating an example of an image of laser light detected by the optical sensor. In FIG. 7, the luminance of each pixel of the optical sensor D is shown in light and dark. As shown in the figure, the image of the laser beam detected by the optical sensor D has a luminance distribution. The control unit 90 determines the position of the center of gravity of the image of the laser light in order to accurately determine the passing position of the laser light at each of the placement locations P12 and P14 facing the optical sensor D from the image having the luminance distribution. 93 (step S104). Specifically, the image processing unit 93 selects a pixel having a luminance equal to or higher than a threshold value, and calculates a weighted average of the position vectors obtained by weighting the selected pixel's position vector with the luminance of the pixel as the barycentric position. Thus, the positions of the laser beams that pass through the arrangement locations P12 and P14 are obtained as the gravity center positions Ga and Gb of the laser beams.

  Subsequently, in step S105, the PID control unit 95 performs a calculation for determining the amount of movement of the piezo mirror Z of each piezo mirror M based on the barycentric position of the laser beam obtained in step S104. Specifically, the PID control unit 95 calculates the position of the optical path in the orthogonal direction R orthogonal to the optical axis OA and the angle of the optical path with respect to the optical axis OA (FIG. 8). Here, FIG. 8 is a diagram for explaining a method of calculating the position and angle of the optical path. In the drawing, the optical path Q in the illumination system S5 is shown with the laser beam exit of the laser oscillator 52 as the origin, the optical axis OA on the horizontal axis, and the orthogonal direction R on the vertical axis. This optical path Q causes a positional shift of a distance r in a direction R perpendicular to the optical axis OA and an angular shift of an angle θ with respect to the optical axis OA.

  The distance la from the origin O to the placement location P12 and the distance lb from the placement location P12 to the placement location P14 are known. Further, the barycentric positions Ga and Gb of the laser light at the respective arrangement locations P12 and P14 have been calculated in step S104 and are already known. Therefore, the equation indicating the optical path Q is expressed by a straight line passing through two points (la, Ga) (la + lb, Gb). Therefore, using this relationship, the PID controller 95 calculates the position r of the optical path Q in the orthogonal direction R and the angle θ of the optical path Q with respect to the optical axis OA from the known values la, lb, Ga, Gb.

The PID control unit 95 calculates a deviation Δ between the rotation amount of the piezo mirror M that makes each of the position r and the angle θ zero and the current rotation amount of the piezo mirror M based on the calculation result. This deviation Δ is calculated for each piezo mirror M at the locations P11 and P13. Then, the PID control unit 95 calculates the amount of movement of each piezo PZ required to rotate the piezo mirror M at each of the arrangement locations P11 and P13 by the deviation Δ based on the following relational expression.
(Movement amount) = Δ × Cp + (Δold−Δ) × Cd + Δav × Ci,
Δold: the deviation Δ calculated in the previous step S105,
Δav: average value of the deviation Δ calculated in step S105 for the predetermined number of times α executed so far,
Cp: proportional gain,
Cd: differential gain,
Ci: integral gain.

  Thus, in step S105, the movement amount is calculated for each of the piezo mirrors PZ of the piezo mirrors M at the locations P11 and P12. In subsequent step S106, it is determined whether or not the movement amount of the piezo PZ obtained in step S105 is within a predetermined amount. If it is not within the predetermined amount, the process proceeds to step S107, the movement amount of the piezo PZ is changed within the predetermined amount, and then the process proceeds to step S108. On the other hand, if it is within the predetermined amount, the process directly proceeds to step S108. In step S108, the piezo mirror M is rotated at each of the placement locations P11 and P13 by driving each piezo PZ by the set amount of movement by the piezo drive unit 97. Thus, in the illumination system S5, based on the result of detecting the position of the laser beam passing through the arrangement places P12 and P14, the piezo mirror M rotates at each of the arrangement places P11 and P13, and the optical path of the laser light is changed. It is corrected. Steps S103 to S108 are repeatedly executed until the pattern drawing is completed (step S109).

  Note that the optical path of the laser beam is similarly corrected for the projection system S4. Specifically, the origin O in FIG. 8 may be set to the diffractive optical element 410, and the placement points P12 and P14 may be replaced with the placement points P16 and P18 to perform the same control as described above. As a result, also in the projection system S4, the piezo mirror M rotates at each of the placement locations P15 and P17 based on the result of detecting the position of the laser light passing through the placement locations P16 and P18. The optical path is corrected.

  As described above, in the first configuration example, the optical path in the illumination system S5 is corrected based on the result of detecting the laser light traveling through the illumination system S5 from the light sources 51 and 52 to the spatial light modulator 41. The light incident position on the spatial light modulator 41 is adjusted. Therefore, even if the temperature change of the atmosphere occurs before the spatial light modulator 41 (that is, the illumination system S5), the change in the optical path due to the temperature change is detected, and the optical path is corrected based on the detection result. Thereby, the incident position of the light to the spatial light modulator 41 can be adjusted accurately. Further, the optical path in the projection system S4 is corrected based on the result of detecting the laser light traveling through the projection system S4 from the spatial light modulator 41 to the substrate W, and the irradiation position of the laser light on the substrate W is adjusted. The Therefore, even if the ambient temperature changes after the spatial light modulator 41 (that is, the projection system S4), the variation in the optical path due to the temperature change is detected, and the optical path is corrected based on the detection result. Thereby, the irradiation position of the laser beam to the substrate W can be accurately adjusted. Thus, in this embodiment, the position of the laser light incident on the spatial light modulator 41 and the position of the laser light irradiated on the substrate W are accurately controlled regardless of the temperature change of the atmosphere, and the substrate W that is the exposure target. It is possible to realize appropriate exposure.

  Further, in the first configuration example, the optical sensor D that detects the position of the laser beam passing through the places P12 and P14 in the illumination system S5 and the laser light that passes through the places P11 and P13 in the illumination system S5. And a piezo mirror M for correcting the optical path. And the incident position of the laser beam to the spatial light modulator 41 can be adjusted by controlling the piezo mirror M based on the detection result of the optical sensor D. In such a configuration, by detecting the position of the laser beam that passes through the arrangement places P12 and P14, it is possible to detect a change in the optical path caused by a temperature change. Then, by correcting the optical path of the laser light passing through the arrangement places P11 and P13 based on this detection result, the incident position of the laser light on the spatial light modulator 41 can be adjusted accurately.

  Further, in the illumination system S5 of the first configuration example, the laser light that passes through each of the plurality of arrangement places P11 and P13 based on the result of detecting the position of the laser beam at each of the plurality of arrangement places P12 and P14. Is corrected. Thus, by providing a plurality of detection points P12 and P14 for detecting the position of the laser beam and correction points P11 and P13 for correcting the optical path of the laser beam, the incident position of the laser beam on the spatial light modulator 41 can be determined. It becomes possible to control with higher accuracy. In particular, the first configuration example is configured so that each of the position r and the angle θ of the optical path can be optimized, and is suitable for controlling the incident position of the laser light on the spatial light modulator 41 with high accuracy.

  In the first configuration example, the optical sensor D for detecting the position of the laser beam passing through the placement points P16 and P18 in the projection system S4 and the laser light passing through the placement points P15 and P17 in the projection system S4. And a piezo mirror M for correcting the optical path. And the irradiation position of the laser beam to the board | substrate W can be adjusted by controlling the piezo mirror M based on the detection result of the optical sensor D. FIG. In such a configuration, by detecting the position of the laser beam that passes through the arrangement places P16 and P18, it is possible to detect a change in the optical path caused by a temperature change. Then, by correcting the optical path of the laser light that passes through the placement locations P15 and P17 based on the detection result, the irradiation position of the laser light on the substrate W can be adjusted accurately.

  Further, in the projection system S4 of the first configuration example, the laser beam that passes through each of the plurality of arrangement locations P15 and P17 based on the result of detecting the position of the laser beam at each of the plurality of arrangement locations P16 and P18. Is corrected. Thus, by providing a plurality of detection points P16 and P18 for detecting the position of the laser beam and a plurality of correction points P15 and P17 for correcting the optical path of the laser beam, the irradiation position of the laser beam on the substrate W can be more accurately determined. It becomes possible to control to. In particular, the first configuration example is configured so that each of the position r and the angle θ of the optical path can be optimized, and is suitable for controlling the irradiation position of the laser beam on the substrate W with high accuracy.

  Thus, in the first configuration example, the pattern drawing apparatus 100 corresponds to the “exposure apparatus” of the present invention, and the control unit 90 functions as “illumination optical path control means” and “projection optical path control means” of the present invention. In the illumination system S5, the beam splitter BS and the optical sensor D cooperate to function as the “illumination optical path detector” of the present invention, and the arrangement locations P12 and P14 correspond to the “illumination optical path detection location” of the present invention. The piezo mirror M functions as the “illumination optical path corrector” of the present invention, and the arrangement locations P11 and P13 correspond to the “illumination optical path correction location” of the present invention. In the projection system S4, the beam splitter BS and the optical sensor D cooperate to function as the “projection optical path detector” of the present invention, and the arrangement locations P16 and P18 correspond to the “projection optical path detection location” of the present invention. The piezo mirror M functions as a “projection optical path corrector” of the present invention, and the arrangement locations P15 and P17 correspond to the “projection optical path correction location” of the present invention.

B. Second Configuration Example of Optical Unit FIG. 9 is a diagram schematically illustrating a second configuration example of the optical unit. The second configuration example is different from the first configuration example in the configuration related to optical path correction, and other configurations are basically common. Therefore, hereinafter, the description will focus on differences from the first configuration example, and description of common configurations will be omitted as appropriate. However, it goes without saying that the second configuration example also has the same configuration as the first configuration example, so that the same effect as the first configuration example is achieved.

  As shown in FIG. 9, a beam splitter BS is arranged at each of the arrangement locations P21 and P22 on the optical axis OA of the illumination system S5. The arrangement places P21 and P22 exist in a section from the lens 53b to the lens 53c, and the beam splitter BS at the arrangement place P21 receives a part of the laser beam from the lens 53b at the arrangement place P22. Reflected toward the BS, the beam splitter BS at the location P22 reflects part of the laser light from the location P21 toward the lens 53c. Each of the beam splitters BS at the locations P21 and P22 is configured to be rotatable by receiving a driving force from the piezo PZ, and also has a function as a piezo mirror M. By controlling the rotation of the beam splitter BS, It is possible to correct the optical path of the laser beam at each of the placement locations P21 and P22.

  Further, the optical sensor D is arranged to face each of the arrangement places P21 and P22. The beam splitter BS at the location P21 transmits part of the laser light from the lens 53b to the optical sensor D facing the location P21, and the beam splitter BS at the location P22 is disposed at the location P21. A part of the laser beam from the laser beam is transmitted to the photosensor D facing the arrangement place P22. The position where the light beam reaches each optical sensor D changes according to the position of the light beam passing through the arrangement places P21 and P22. Accordingly, each optical sensor D detects the position of the laser light passing through the corresponding arrangement locations P21 and P22.

  Then, the control unit 90 rotates the beam splitter BS at each of the arrangement places P21 and P22 based on the result of obtaining the position of the laser light passing through the arrangement places P21 and P22 from the detection result of the optical sensor D. Control. Thereby, the optical path of the laser beam of the illumination system S5 is corrected, and the incident position of the laser beam on the diffractive optical element 410 is adjusted. Specifically, the same control as the detailed contents in the first configuration example can be performed, and the position r of the optical path of the laser light and the result of detecting the position of the laser light at two different places P21 and P22 By obtaining the angle θ and controlling the rotation amount of the beam splitter BS so as to suppress the deviation between the position r and the angle θ, the incident position of the laser light on the diffractive optical element 410 is adjusted.

  A beam splitter BS is arranged at each of the arrangement places P23 and P24 on the optical axis OA of the projection system S4. The arrangement place P23 exists in a section from the diffractive optical system 410 to the aperture 43a, and the beam splitter BS at the arrangement place P23 directs a part of the laser light from the diffractive optical system 410 toward the aperture 43a. reflect. Further, the arrangement location P24 exists in a section from the stop 43c to the lens 43d, and the beam splitter BS at the installation location P24 reflects a part of the laser light from the stop 43c toward the lens 43d. . The beam splitter BS at each of the arrangement locations P23 and P24 is configured to be rotatable by receiving a driving force from the piezo PZ, and also has a function as a piezo mirror M. By controlling the rotation of the beam splitter BS, It is possible to correct the optical path of the laser beam at each of the arrangement places P23 and P24.

  Further, the optical sensor D is arranged to face each of the arrangement places P23 and P24. The beam splitter BS at the location P23 transmits a part of the laser light from the diffractive optical element 410 to the optical sensor D facing the location P23, and the beam splitter BS at the location P24 has the aperture 43c. A part of the laser beam from the light is transmitted to the optical sensor D facing the arrangement place P24. The position at which the light beam reaches each optical sensor D varies depending on the position of the light beam that passes through the locations P23 and P24. Accordingly, each optical sensor D detects the position of the laser light passing through the corresponding arrangement places P23 and P24.

  Then, the control unit 90 rotates the beam splitter BS at each of the arrangement places P23 and P24 based on the result of obtaining the position of the laser light passing through the arrangement places P23 and P24 from the detection result of the optical sensor D. Control. Thereby, the optical path of the laser beam of the projection system S4 is corrected, and the irradiation position of the laser beam on the substrate W is adjusted. Specifically, the same control as the detailed contents in the first configuration example can be performed, and the position r of the optical path of the laser light and the result of detecting the position of the laser light at two different places P23 and P24 By obtaining the angle θ and controlling the rotation amount of the beam splitter BS so as to suppress the deviation between the position r and the angle θ, the irradiation position of the laser beam on the substrate W is adjusted.

  As described above, even in the second configuration example, even if the temperature change of the atmosphere occurs before the spatial light modulator 41 (that is, the illumination system S5), the change in the optical path due to the temperature change is detected. By correcting the optical path based on the detection result, the incident position of the light to the spatial light modulator 41 can be adjusted accurately. Even if the temperature of the atmosphere changes after the spatial light modulator 41 (that is, the projection system S4), a change in the optical path caused by the temperature change is detected, and the optical path is corrected based on the detection result. Thereby, the irradiation position of the laser beam to the substrate W can be accurately adjusted. As a result, the exposure position of the substrate W to be exposed can be appropriately controlled by accurately controlling the incident position of the laser beam on the spatial light modulator 41 and the irradiation position of the laser beam on the substrate W regardless of the temperature change of the atmosphere. Can be realized.

  Thus, in the second configuration example, the pattern drawing apparatus 100 corresponds to the “exposure apparatus” of the present invention, and the control unit 90 functions as “illumination optical path control means” and “projection optical path control means” of the present invention. In the illumination system S5, the beam splitter BS and the optical sensor D cooperate to function as the “illumination optical path detector” of the present invention, and the arrangement locations P21 and P22 correspond to the “illumination optical path detection location” of the present invention. The beam splitter BS functions as the “illumination optical path corrector” of the present invention, and the arrangement locations P21 and P22 correspond to the “illumination optical path correction location” of the present invention. In the projection system S4, the beam splitter BS and the optical sensor D cooperate to function as the “projection optical path detector” of the present invention, and the arrangement locations P23 and P24 correspond to the “projection optical path detection location” of the present invention. The beam splitter BS functions as a “projection optical path corrector” of the present invention, and the arrangement locations P23 and P24 correspond to the “projection optical path correction location” of the present invention.

C. Third Configuration Example of Optical Unit FIG. 10 is a diagram schematically illustrating a third configuration example of the optical unit. The third configuration example is different from the first configuration example in the configuration related to optical path correction, and other configurations are basically common. Therefore, hereinafter, the description will focus on differences from the first configuration example, and description of common configurations will be omitted as appropriate. However, it goes without saying that the third configuration example also has the same configuration as the first configuration example, so that the same effect as the first configuration example is achieved.

  As shown in FIG. 10, a piezo mirror M and a parallel plate B are provided at locations P31 and P32 on the optical axis OA of the illumination system S5. The disposition locations P31 and P32 exist in the section from the lens 53b to the lens 53c, and the piezo mirror M at the disposition location P31 directs the laser beam from the lens 53b toward the parallel plate B at the disposition location P32. The parallel plate B at the location P32 transmits the laser light from the piezo mirror M at the location P31 toward the lens 53c. The parallel flat plate B is a light-transmitting flat plate made of glass or the like. One main surface of the parallel flat plate B is a laser light incident surface, and the other main surface of the parallel flat plate B is a laser light emission surface. Further, the parallel plate B is configured to be rotatable under the control of the control unit 90, and the position of the laser beam passing through the parallel plate B from one main surface to the other main surface in the orthogonal direction R is parallel plate B. It changes according to the rotation angle. That is, the parallel plate B has a function of displacing the optical path of the laser light in the orthogonal direction R without affecting the angle of the laser light with respect to the optical axis OA.

  In the illumination system S5 having such a configuration, the angle of the optical path of the laser beam with respect to the optical axis OA can be adjusted by rotating the piezo mirror M at the location P31. Moreover, the position of the optical path of the laser beam in the orthogonal direction R can be adjusted by rotating the parallel flat plate B of the arrangement place P32. That is, the adjustment of the position r and the angle θ of the optical path of the laser beam can be separated and can be carried by the piezo mirror M and the parallel plate B, respectively.

  In addition, a beam splitter BS is arranged at each of the arrangement places P33 and P34 on the optical axis OA of the illumination system S5. Further, the optical sensor D is arranged to face each of the arrangement places P33 and P34. The arrangement places P33 and P34 exist between the parallel plate B and the lens 53c. The beam splitter BS at the arrangement place P33 transmits a part of the laser beam from the parallel plate B to the beam splitter BS at the arrangement place P34, while a part of the laser beam from the parallel plate B is provided at the arrangement place. Reflects to the photosensor D facing P33. Further, the beam splitter BS at the arrangement place P34 transmits a part of the laser beam from the beam splitter BS at the arrangement place P33 to the lens 53c, while a part of the laser beam from the beam splitter BS at the arrangement place P33. Is reflected to the optical sensor D facing the arrangement place P34. The position where the light beam reaches each optical sensor D changes according to the position of the light beam passing through the arrangement places P33 and P34. Accordingly, each optical sensor D detects the position of the laser beam that passes through the corresponding arrangement locations P33 and P34.

  Then, the control unit 90 determines, based on the detection result of the optical sensor D, the position of the laser beam that passes through the placement locations P33 and P34, and the piezo mirror M and the parallel plate B at the placement locations P31 and P32. Control each rotation. Thereby, the optical path of the laser beam of the illumination system S5 is corrected, and the incident position of the laser beam on the diffractive optical element 410 is adjusted. Specifically, the same control as the detailed contents in the first configuration example can be performed, and the position r of the optical path of the laser light and the result of detecting the position of the laser light at two different places P21 and P22 By obtaining the angle θ and controlling the rotation amounts of the beam splitter BS and the parallel plate B so as to suppress the deviation between the position r and the angle θ, the incident position of the laser light on the diffractive optical element 410 is adjusted. . In particular, in the third configuration example, the adjustment of the position r and the angle θ of the optical path of the laser light can be separated and carried by the piezo mirror M and the parallel plate B, respectively, so that the piezo mirror M is rotated by the angle θ. At the same time, by simply rotating the parallel plate B by an angle corresponding to the position r, the optical path of the laser beam can be appropriately corrected, and control is simplified.

  Further, as shown in FIG. 10, a piezo mirror M and a parallel plate B are provided at locations P35 and P36 on the optical axis OA of the projection system S4. The disposition locations P35 and P36 exist in a section from the diffractive optical element 410 to the aperture 43a, and the piezo mirror M at the disposition location P35 applies the laser beam from the diffractive optical element 410 in parallel to the disposition location P36. Reflected toward the flat plate B, the parallel flat plate B at the place P36 transmits the laser light from the piezo mirror M at the place P35 toward the aperture 43a. The specific configuration and function of the parallel plate B are the same as those of the previous illumination system S5.

  In the projection system S4 having such a configuration, the angle of the optical path of the laser beam with respect to the optical axis OA can be adjusted by rotating the piezo mirror M at the arrangement location P35. Moreover, the position of the optical path of the laser beam in the orthogonal direction R can be adjusted by rotating the parallel plate B of the arrangement place P36. That is, the adjustment of the position r and the angle θ of the optical path of the laser beam can be separated and can be carried by the piezo mirror M and the parallel plate B, respectively.

  A beam splitter BS is arranged at each of the arrangement places P35 and P36 on the optical axis OA of the projection system S4. Furthermore, the optical sensor D is arranged facing each of the arrangement places P35 and P36. The disposition locations P35 and P36 exist between the diaphragm 43c and the lens 43d. The beam splitter BS at the location P37 transmits a part of the laser beam from the aperture 43c to the beam splitter BS at the location P38, while a part of the laser beam from the aperture 43c is transmitted to the location P37. Reflected to the opposing optical sensor D. Further, the beam splitter BS at the arrangement place P38 transmits part of the laser light from the beam splitter BS at the arrangement place P37 to the lens 43d, while part of the laser light from the beam splitter BS at the arrangement place P37. Is reflected to the optical sensor D facing the arrangement place P38. The position at which the light beam reaches each optical sensor D varies depending on the position of the light beam that passes through the locations P37 and P38. Therefore, each optical sensor D detects the position of the laser beam that passes through the corresponding arrangement locations P37 and P38.

  And the control part 90 is based on the result of having calculated | required the position of the laser beam which passes the arrangement | positioning locations P37 and P38 from the detection result of the optical sensor D, The piezoelectric mirror M of the arrangement | positioning locations P35 and P36, and the parallel plate B Control each rotation. Thereby, the optical path of the laser beam of the projection system S4 is corrected, and the irradiation position of the laser beam on the substrate W is adjusted. Specifically, the same control as the detailed contents in the first configuration example can be performed, and the position r of the optical path of the laser light and the result of detecting the position of the laser light at two different locations P37 and P38 By obtaining the angle θ and controlling the rotation amounts of the beam splitter BS and the parallel plate B so as to suppress the deviation between the position r and the angle θ, the irradiation position of the laser beam on the substrate W is adjusted. In particular, in the third configuration example, the adjustment of the position r and the angle θ of the optical path of the laser light can be separated and carried by the piezo mirror M and the parallel plate B, respectively, so that the piezo mirror M is rotated by the angle θ. At the same time, by simply rotating the parallel plate B by an angle corresponding to the position r, the optical path of the laser beam can be appropriately corrected, and control is simplified.

  As described above, even in the third configuration example, even if the temperature change of the atmosphere occurs before the spatial light modulator 41 (that is, the illumination system S5), the change in the optical path caused by the temperature change is detected. By correcting the optical path based on the detection result, the incident position of the light to the spatial light modulator 41 can be adjusted accurately. Even if the temperature of the atmosphere changes after the spatial light modulator 41 (that is, the projection system S4), a change in the optical path caused by the temperature change is detected, and the optical path is corrected based on the detection result. Thereby, the irradiation position of the laser beam to the substrate W can be accurately adjusted. As a result, the exposure position of the substrate W to be exposed can be appropriately controlled by accurately controlling the incident position of the laser beam on the spatial light modulator 41 and the irradiation position of the laser beam on the substrate W regardless of the temperature change of the atmosphere. Can be realized.

  Thus, in the third configuration example, the pattern drawing apparatus 100 corresponds to the “exposure apparatus” of the present invention, and the control unit 90 functions as “illumination optical path control means” and “projection optical path control means” of the present invention. In the illumination system S5, the beam splitter BS and the optical sensor D cooperate to function as the “illumination optical path detector” of the present invention, and the arrangement locations P33 and P34 correspond to the “illumination optical path detection location” of the present invention. The piezo mirror M and the parallel plate B function as the “illumination optical path corrector” of the present invention, and the arrangement locations P31 and P32 correspond to the “illumination optical path correction location” of the present invention. In the projection system S4, the beam splitter BS and the optical sensor D cooperate to function as the “projection optical path detector” of the present invention, and the arrangement locations P37 and P38 correspond to the “projection optical path detection location” of the present invention. The piezo mirror M and the parallel plate B function as the “projection optical path corrector” of the present invention, and the arrangement locations P35 and P36 correspond to the “projection optical path correction location” of the present invention.

D. Others The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, laser light detection is performed at two places in the illumination system S5 and the projection system S4. However, the number of locations where laser light is detected is not limited to this, and may be 1 or 3 or more. In the illumination system S5 and the projection system S4, the number of optical path correction members (piezo mirror M, beam splitter BS, parallel plate B, etc.) for correcting the optical path is not limited to the above.

  Moreover, in the said embodiment, the detail of arrangement | positioning of the optical sensor D was not mentioned in particular. However, various modifications can be made to the arrangement of the optical sensor D. A specific modification will be described as follows. In addition, although demonstrated using a 1st structural example here, the same deformation | transformation is possible also about another structural example.

  In the illumination system S5 of the first configuration example, the detection points P12 and P14 where the laser beam is detected by the optical sensor D are arranged along the optical axis OA. At this time, for the photosensor D facing the last detection location P14 among the detection locations P12 and P14, the distance from the detection location P14 to the photosensor D, the distance from the detection location P14 to the diffractive optical element 410, and Are equal, the optical sensor D can detect the incident position of the laser beam on the diffractive optical element 410 itself. Therefore, it is extremely suitable for controlling the incident position of the laser beam of the diffractive optical element 410.

  Alternatively, in the projection system S4 of the first configuration example, the detection points P16 and P18 where the laser light is detected by the optical sensor D are arranged along the optical axis OA. At this time, for the photosensor D facing the last detection location P18 among the detection locations P16 and P18, the distance from the detection location P18 to the photosensor D, the distance from the detection location P18 to the diffractive optical element 410, and Are equal, the optical sensor D can detect the irradiation position itself of the laser beam to the substrate W to be exposed. Therefore, it is extremely suitable for controlling the irradiation position of the laser beam on the substrate W.

  In the above embodiment, the optical sensor D detects a two-dimensional image of the laser light (in other words, a two-dimensional image projected on the beam splitter BS). However, a line sensor that detects a one-dimensional image can also be used as the optical sensor D. Even in this case, the position of the laser beam can be detected at least in the long axis direction of the line sensor. Alternatively, if two line sensors are arranged orthogonally, the position of the laser beam can be detected in two dimensions. When such a line sensor is used, laser light can be detected at short time intervals, and the optical path can be quickly corrected for fluctuations in the optical path.

  In the above embodiment, the laser beam split by the beam splitter BS is directly incident on the optical sensor D. However, an optical element such as an expander for enlarging / reducing the image of the laser beam may be provided between the beam splitter BS and the optical sensor D. In short, it is sufficient if the position of the laser beam at the location where the optical sensor D faces can be detected by the optical sensor D.

  In the above embodiment, the spatial light modulator 41 is configured to modulate the laser light using the diffractive optical element 410. However, a spatial light modulator 41 that modulates laser light using a modulation element other than the diffractive optical element 410 can also be used.

  In the above embodiment, the piezo mirror M and the beam splitter BS provided for correcting the optical path are driven by the piezo PZ. However, the drive means is not limited to the piezo PZ, and may be a motor, for example.

  Further, the specific method for calculating the position of the laser light based on the optical sensor D and the specific method for calculating the position r and the angle θ of the optical path are not limited to the above-described contents. Further, a configuration for extracting and separating the optical path position r and angle θ from the detection result of the optical sensor D is not essential. For example, a table or function indicating the relationship between the detection value of the optical sensor D and the amount of movement of the optical path correction member such as the piezo mirror M is prepared, and the detection result of the optical sensor D is applied to the relationship to correct the optical path. It may be configured to correct the optical path by moving the member.

  Moreover, in the pattern drawing apparatus 100 of the said embodiment, it exposed by the 0th-order laser beam. However, the present invention can also be applied to the pattern writing apparatus 100 that performs exposure with a first-order or higher-order laser beam.

  INDUSTRIAL APPLICABILITY The present invention can be applied to all techniques for modulating light emitted from a light source with a spatial light modulator and irradiating an exposure target. In particular, pattern drawing is performed on a substrate with light modulated by the spatial light modulator. It is suitable for a pattern drawing apparatus. As a substrate to be processed, various substrates such as a semiconductor substrate, a printed substrate, a color filter substrate, a glass substrate for a flat panel display provided in a liquid crystal display device or a plasma display device, and an optical disk substrate can be used. is there.

100: Pattern drawing device (exposure device)
90... Control unit (illumination optical path control means, projection optical path control means)
S5 ... Illumination system S4 ... Projection system W ... Substrate (exposure target)
M ... Piezo mirror (illumination optical path corrector, projection optical path corrector)
BS ... Beam splitter (illumination optical path detector, projection optical path detector, illumination optical path corrector, projection optical path corrector)
B ... Parallel plate (illumination optical path corrector, projection optical path corrector)
D ... Optical sensor (illumination optical path detector, projection optical path detector)
P12, P14: Location (illumination optical path detection location)
P11, P13 ... Installation location (illumination optical path correction location)
P16, P18 ... installation location (projection optical path detection location)
P15, P17: Arrangement location (projection optical path correction location)
P21, P22 ... installation location (illumination optical path detection location, illumination optical path correction location)
P23, P24 ... arrangement location (projection optical path detection location, projection optical path correction location)
P33, P34 ... Installation location (illumination optical path detection location)
P31, P32 ... installation location (illumination optical path correction location)
P37, P38 ... Arrangement location (projection optical path detection location)
P35, P36: Arrangement location (projection optical path correction location)

The exposure method according to the present invention, in order to achieve the above object, the exposure of the modulated light obtained by modulating the light emitted from the light source by the spatial light modulator is irradiated to the exposure target is exposed to exposure light object Adjusting a light incident position on the spatial light modulator by correcting a light path in the illumination system based on a result of detecting light traveling through the illumination system from the light source to the spatial light modulator. Adjusting the light irradiation position on the exposure target by correcting the optical path in the projection system based on the result of detecting the light traveling through the projection system from the spatial light modulator to the exposure target. It is characterized by that.

In addition, a cassette placement unit 104 for placing the cassette C is disposed outside the main body of the pattern drawing apparatus 100 at a position adjacent to the transfer area 103. Further, the transfer device 70 corresponding to the cassette placement unit 104 and disposed in the transfer area 103 inside the main body takes out the unprocessed substrate W accommodated in the cassette C placed on the cassette placement unit 104. It is transported (loaded) into the processing area 102, the processed substrate W from the processing region 102 out by (unloading) accommodated in the cassette C. Delivery of the cassette C to the cassette mounting unit 104 is performed by an external transport device (not shown). The loading process of the unprocessed substrate W and the unloading process of the processed substrate W are performed by operating the transfer device 70 in accordance with an instruction from the control unit 90.

In addition, a beam splitter BS is arranged at each of the arrangement places P37 and P38 on the optical axis OA of the projection system S4. Further, the optical sensor D is arranged to face each of the arrangement places P37 and P38 . The arrangement places P37 and P38 exist between the diaphragm 43c and the lens 43d. The beam splitter BS at the location P37 transmits a part of the laser beam from the aperture 43c to the beam splitter BS at the location P38, while a part of the laser beam from the aperture 43c is transmitted to the location P37. Reflected to the opposing optical sensor D. Further, the beam splitter BS at the arrangement place P38 transmits part of the laser light from the beam splitter BS at the arrangement place P37 to the lens 43d, while part of the laser light from the beam splitter BS at the arrangement place P37. Is reflected to the optical sensor D facing the arrangement place P38. The position at which the light beam reaches each optical sensor D varies depending on the position of the light beam that passes through the locations P37 and P38. Therefore, each optical sensor D detects the position of the laser beam that passes through the corresponding arrangement locations P37 and P38.

Claims (8)

A light source that emits light;
A spatial light modulator that emits modulated light that is irradiated onto an exposure target by modulating light emitted from the light source;
Illumination that adjusts the incident position of light to the spatial light modulator by correcting the light path in the illumination system based on the detection result of light traveling through the illumination system from the light source to the spatial light modulator Optical path control means;
A projection optical path that adjusts the irradiation position of the light to the exposure target by correcting the optical path in the projection system based on a result of detecting light traveling through the projection system reaching the exposure target from the spatial light modulator An exposure apparatus comprising a control means.   The illumination optical path control means includes an illumination optical path detector that detects a position of light passing through an illumination optical path detection location in the illumination system, and an illumination that corrects an optical path of light passing through an illumination optical path correction location in the illumination system. 2. The light path correction device according to claim 1, further comprising: an optical path corrector, wherein the incident position of the light to the spatial light modulator is adjusted by controlling the illumination optical path corrector based on a detection result of the illumination optical path detector. Exposure device.   The illumination light path detector detects a light position at each of the plurality of illumination light path detection points, and the illumination light path corrector corrects an optical path of light passing through each of the plurality of illumination light path correction points. Item 3. The exposure apparatus according to Item 2.   The illumination optical path control means is configured so that the illumination optical path detector detects the position of light at each of the plurality of illumination optical path detection locations, and the illumination optical path corrector at each of the plurality of illumination optical path correction locations. By controlling the correction of the optical path, the position of the optical path in the direction orthogonal to the optical axis of the illumination system and the angle of the optical path with respect to the optical axis of the illumination system are adjusted, and the incident position of the light to the spatial light modulator 4. The exposure apparatus according to claim 3, wherein the exposure is adjusted.   The projection optical path control means includes a projection optical path detector that detects a position of light passing through a projection optical path detection location in the projection system, and a projection that corrects an optical path of light passing through a projection optical path correction location in the projection system. 5. The light irradiation position of the exposure target is adjusted by controlling the projection light path correction device based on a detection result of the projection light path detector. The exposure apparatus according to one item.   The projection optical path detector detects a light position at each of the plurality of projection optical path detection points, and the projection optical path corrector corrects an optical path of light passing through each of the plurality of projection optical path correction points. Item 6. The exposure apparatus according to Item 5.   The projection optical path control means is configured to detect the position of the light at each of the plurality of projection optical path detection points by the projection optical path detector at each of the plurality of projection optical path correction points by the projection light path correction unit. By controlling the correction of the optical path, the position of the optical path in the direction orthogonal to the optical axis of the projection system and the angle of the optical path with respect to the optical axis of the projection system are adjusted, and the irradiation position of the light to the exposure target is adjusted. An exposure apparatus according to claim 6. In an exposure method of exposing the exposure target by irradiating the exposure target with modulated light obtained by modulating light emitted from the light source with a spatial light modulator,
Adjusting the incident position of the light to the spatial light modulator by correcting the light path in the illumination system based on the result of detecting the light traveling through the illumination system from the light source to the spatial light modulator When,
Adjusting the light irradiation position on the exposure target by correcting the light path in the projection system based on the result of detecting the light traveling through the projection system reaching the exposure target from the spatial light modulator; An exposure method comprising:

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