JP2015192079A - Light irradiation apparatus and drawing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily produce an optical path length difference generation section.SOLUTION: A light irradiation apparatus 31 includes a light source section 4 for emitting a laser beam and an irradiation optical system 5 for guiding the laser beam to an irradiation surface 320 along an optical axis J1. The irradiation optical system 5 includes an optical path length difference generation section 61, a split lens section 62 and a condenser lens section 63. The optical path length difference generation section 61 includes a plurality of translucent parts having mutually different optical path lengths. The split lens section 62 includes a plurality of lenses for splitting incident light. The condenser lens section 63 overlaps irradiation regions 50 of beams from the plurality of lenses on the irradiation surface 320. An intermediate variable magnification section 64 is formed between the optical path length difference generation section 61 and the split lens section 62. Beams having passed through the plurality of translucent parts are made incident on the plurality of lenses respectively through the intermediate variable magnification section 64 constituting a reduction optical system. Consequently, the optical path length difference generation section 61 can be easily produced by forming the optical path length difference generation section 61 larger than the split lens section 62 in an array direction of the translucent parts.

Description

  The present invention relates to a light irradiation apparatus and a drawing apparatus.

  Conventionally, a technique for uniformly irradiating a predetermined surface with laser light emitted from a light source such as a semiconductor laser has been proposed. For example, in a light irradiation device in which laser light incident from a light source unit is divided by a plurality of lenses in a cylindrical lens array, and an irradiation area of light from the plurality of lenses is overlapped on an irradiation surface by another lens, the light source unit An optical path length difference generation unit is provided between the cylindrical lens array and the cylindrical lens array. The optical path length difference generating unit is provided with a plurality of light transmitting parts that mutually cause an optical path length difference longer than the coherence length (coherence distance) of the laser light, and the light that has passed through the plurality of light transmitting parts is a plurality of light transmitting parts. Each enters the lens. Thereby, generation | occurrence | production of an interference fringe is prevented and uniform intensity distribution of the light irradiated on an irradiation surface is achieved (for example, refer patent documents 1 thru | or 3 as such an apparatus).

JP-A 61-169815 JP 2004-12757 A JP 2006-49656 A

  By the way, in order to manufacture the cylindrical lens array with high accuracy, it is preferable to use photolithography. Generally, a small cylindrical lens array is manufactured using photolithography. On the other hand, in the above light irradiation device, it is necessary to match the pitch of the plurality of light transmitting portions in the optical path length difference generation unit with the pitch of the plurality of lenses in the cylindrical lens array, and thus it is necessary to produce a small optical path length difference generation unit. There is. However, in the optical path length difference generation unit, it is difficult to use photolithography because the lengths (thicknesses) of the plurality of light transmission units in the optical axis direction are different from each other. It is not easy to manufacture a small optical path length difference generating unit with high precision by machining.

  Further, depending on the size of the optical path length difference generation unit, it may be required to shorten the length of the optical path length difference generation unit in the optical axis direction.

  The present invention has been made in view of the above problems, and has an object to easily produce an optical path length difference generation unit and to reduce the length of the optical path length difference generation unit in the optical axis direction.

  The invention according to claim 1 is a light irradiating device, wherein the light source unit emits laser light toward a predetermined position, and is disposed at the predetermined position, and the laser light from the light source unit is directed along the optical axis. A split lens that includes a plurality of lenses arranged in a direction perpendicular to the optical axis, and divides incident light by the plurality of lenses. And a plurality of light transmitting portions arranged in a direction perpendicular to the optical axis, and the plurality of light transmitting portions have optical path lengths different from each other, and the laser light path in the path of the laser light An intermediate magnification unit disposed between the split lens unit and the optical path length difference generation unit; and the laser light path, the split lens unit and the optical path length difference generation unit are disposed closer to the irradiation surface side, An irradiation area of light from the plurality of lenses on the irradiation surface A light condensing lens unit, wherein the optical path length difference generation unit is arranged on the irradiation surface side of the split lens unit in the path of the laser light, and the light that has passed through the plurality of lenses passes through the magnifying optical system. Each incident on the plurality of light transmitting parts via the intermediate zooming part, or in the laser light path, the split lens part is disposed closer to the irradiation surface than the optical path length difference generation part, The light that has passed through the plurality of light transmitting portions is incident on the plurality of lenses via the intermediate zooming portion that constitutes the reduction optical system.

  A second aspect of the present invention is the light irradiation apparatus according to the first aspect, wherein the intermediate zooming unit constitutes a double-sided telecentric optical system.

  Invention of Claim 3 is the light irradiation apparatus of Claim 2, Comprising: In the path | route of the said laser beam, the said optical path length difference production | generation part is arrange | positioned at the said irradiation surface side rather than the said division | segmentation lens part, The intermediate zooming unit forms an image of the exit surface of the plurality of lenses in or near the plurality of light transmitting units.

  Invention of Claim 4 is the light irradiation apparatus in any one of Claim 1 thru | or 3, Comprising: The said irradiation optical system permeate | transmits the said optical path length difference production | generation part, and is the said some light transmission part. A reflection unit is further provided for turning back the light emitted from the plurality of emission surfaces and allowing the light to enter each of the plurality of emission surfaces.

  Invention of Claim 5 is the light irradiation apparatus of Claim 4, Comprising: The said reflection part is the said some light in parallel with the emission direction of the said light in the said light emission direction. Each is incident on the exit surface.

  The invention according to claim 6 is a light irradiation device, a light source unit that emits laser light toward a predetermined position, and the laser light from the light source unit that is arranged at the predetermined position along the optical axis. A split lens that includes a plurality of lenses arranged in a direction perpendicular to the optical axis, and divides incident light by the plurality of lenses. And an optical path length difference generation unit having a plurality of light transmission parts arranged in a direction perpendicular to the optical axis, the plurality of light transmission parts having different optical path lengths, and the optical path length difference generation part. Reflecting portions that pass through and radiate light emitted from a plurality of exit surfaces of the plurality of light-transmitting portions and respectively enter the plurality of exit surfaces, and the split lens portion and the optical path length difference in the laser light path Arranged on the irradiation surface side of the generation unit, on the irradiation surface A condensing lens unit that overlaps irradiation regions of light from the plurality of lenses, wherein the optical path length difference generation unit is disposed closer to the irradiation surface than the split lens unit in the laser beam path, The light that has passed through the lens is incident on each of the plurality of translucent sections, or the split lens section is disposed closer to the irradiation surface than the optical path length difference generating section in the path of the laser light, and the plurality of translucent sections The light that has passed through the light part enters each of the plurality of lenses.

  The invention according to claim 7 is the light irradiation device according to claim 6, wherein the reflecting portion emits the light emitted from the plurality of emission surfaces in parallel to the emission direction of the light. Each is incident on the exit surface.

  Invention of Claim 8 is a drawing apparatus, Comprising: The light irradiation apparatus in any one of Claim 1 thru | or 7, The spatial light modulator arrange | positioned at the said irradiation surface in the said light irradiation apparatus, The said, A projection optical system for guiding light spatially modulated by a spatial light modulator onto an object, a movement mechanism for moving an irradiation position of the spatially modulated light on the object, and an irradiation position of the irradiation mechanism by the movement mechanism A control unit that controls the spatial light modulator in synchronization with the movement.

  According to the first to fifth aspects of the present invention, the optical path length difference generation unit can be made larger than the split lens unit with respect to the arrangement direction of the light transmitting units, and the optical path length difference generation unit can be easily manufactured.

  In the inventions according to claims 4 to 7, the length of the optical path length difference generation unit in the optical axis direction can be shortened.

It is a figure which shows the structure of the drawing apparatus which concerns on 1st Embodiment. It is a figure which shows the structure of a light irradiation apparatus. It is a figure which shows the structure of a light irradiation apparatus. It is a figure which shows the vicinity of an optical path length difference production | generation part and a division | segmentation lens part. It is a figure which shows intensity distribution of the light on an irradiation surface. It is a figure which shows the structure of the irradiation optical system of a comparative example. It is a figure which shows the other example of a light irradiation apparatus. It is a figure which shows the other example of a light irradiation apparatus. It is a perspective view which shows an optical path length difference production | generation part. It is a figure which simplifies and shows a light irradiation apparatus. It is a figure which shows the other example of a light irradiation apparatus. It is a figure which shows the other example of a light irradiation apparatus. It is a figure which shows the other example of a light irradiation apparatus. It is a figure which shows the other example of a light irradiation apparatus. It is a figure which shows the vicinity of a reflection part. It is a figure which shows the other example of a light irradiation apparatus. It is a figure which shows the other example of a light irradiation apparatus. It is a figure which shows the vicinity of a reflection part. It is a figure which shows the structure of the light irradiation apparatus which concerns on 2nd Embodiment. It is a figure which shows the structure of the light irradiation apparatus which concerns on 2nd Embodiment. It is a figure which shows the vicinity of a division | segmentation lens part. It is a figure which shows the other example of a light irradiation apparatus. It is a figure which shows the other example of a light irradiation apparatus. It is a figure which shows the other example of a light irradiation apparatus. It is a figure which shows the other example of a light irradiation apparatus. It is a figure which shows the other example of a light irradiation apparatus. It is a figure which shows the other example of a light irradiation apparatus.

  FIG. 1 is a diagram showing a configuration of a drawing apparatus 1 according to the first embodiment of the present invention. The drawing apparatus 1 is a direct drawing apparatus that draws a pattern by irradiating the surface of a substrate 9 such as a semiconductor substrate or a glass substrate, to which a photosensitive material is applied, with a light beam. The drawing apparatus 1 includes a stage 21, a moving mechanism 22, a light irradiation device 31, a spatial light modulator 32, a projection optical system 33, and a control unit 11. The stage 21 holds the substrate 9, and the moving mechanism 22 moves the stage 21 along the main surface of the substrate 9. The moving mechanism 22 may rotate the substrate 9 about an axis perpendicular to the main surface.

  The light irradiation device 31 irradiates the spatial light modulator 32 with line-shaped light via the mirror 39. Details of the light irradiation device 31 will be described later. The spatial light modulator 32 is, for example, a diffraction grating type and a reflection type, and is a diffraction grating capable of changing the depth of the grating. The spatial light modulator 32 is manufactured using a semiconductor device manufacturing technique. The diffraction grating type optical modulator used in the present embodiment is, for example, GLV (Grating Light Valve) (registered trademark of Silicon Light Machines (Sunnyvale, Calif.)). The spatial light modulator 32 has a plurality of grating elements arranged in a line, and each grating element is between a state where the first-order diffracted light is emitted and a state where zero-order diffracted light (0th-order light) is emitted. Transition. In this way, the spatially modulated light is emitted from the spatial light modulator 32.

  The projection optical system 33 includes a light shielding plate 331, a lens 332, a lens 333, a diaphragm plate 334, and a focusing lens 335. The light shielding plate 331 shields part of the ghost light and the high-order diffracted light and allows the light from the spatial light modulator 32 to pass through. The lenses 332 and 333 constitute a zoom unit. The diaphragm plate 334 shields the (± 1) order diffracted light (and higher order diffracted light) and allows the 0th order diffracted light to pass through. The light that has passed through the diaphragm plate 334 is guided onto the main surface of the substrate 9 by the focusing lens 335. In this way, the light spatially modulated by the spatial light modulator 32 is guided onto the substrate 9 by the projection optical system 33.

  The control unit 11 is connected to the light irradiation device 31, the spatial light modulator 32, and the moving mechanism 22, and controls these configurations. In the drawing apparatus 1, when the moving mechanism 22 moves the stage 21, the irradiation position on the substrate 9 of the light from the spatial light modulator 32 moves. Further, the control unit 11 controls the spatial light modulator 32 in synchronization with the movement of the irradiation position by the moving mechanism 22. Thereby, a desired pattern is drawn on the photosensitive material on the substrate 9.

  2 and 3 are diagrams showing the configuration of the light irradiation device 31. FIG. 2 and 3, the direction parallel to the optical axis J1 of the irradiation optical system 5 to be described later is shown as the Z direction, and the directions perpendicular to the Z direction and perpendicular to each other are shown as the X direction and the Y direction (hereinafter referred to as “the X direction”). The same). FIG. 2 shows the configuration of the light irradiation device 31 viewed along the Y direction, and FIG. 3 shows the configuration of the light irradiation device 31 viewed along the X direction.

  The light irradiation device 31 includes a light source unit 4 and an irradiation optical system 5. The light source unit 4 includes, for example, a light source 41 that is a semiconductor laser (Laser Diode) and a collimator lens (for example, an aspheric collimator lens) 42. Laser light emitted from the light source 41 is collimated by the collimator lens 42. The irradiation optical system 5 is disposed at a position where the light source unit 4 emits laser light. The irradiation optical system 5 is a surface of the spatial light modulator 32 that is an irradiation surface (indicated by a broken line denoted by reference numeral 320 in FIGS. 2 and 3) along the optical axis J1 of the laser light, that is, a plurality of light beams. To the surface of the lattice element. As described above, since the light from the light irradiation device 31 is irradiated to the spatial light modulator 32 via the mirror 39, the light irradiation device 31 actually includes the mirror 39 as a constituent element. In FIG. 2 and FIG. 3, the mirror 39 is omitted for convenience of illustration (the same applies hereinafter).

  The irradiation optical system 5 includes an optical path length difference generation unit 61, a split lens unit 62, a condenser lens unit 63, an intermediate zoom unit 64, and lenses 51 and 52. In the irradiation optical system 5, from the light source unit 4 toward the irradiation surface 320, the lenses 51 and 52, the optical path length difference generation unit 61, the intermediate zooming unit 64, the split lens unit 62, and the condenser lens unit 63 are arranged in this order. Is arranged along the optical axis J1. The collimated laser beam from the light source unit 4 enters the optical path length difference generation unit 61 through the lenses 51 and 52 in parallel with the optical axis J1. The lenses 51 and 52 constitute an afocal optical system, specifically, a both-side telecentric optical system, and make incident laser light enter the optical path length difference generation unit 61 as parallel light parallel to the optical axis J1. At this time, a cross section perpendicular to the optical axis J 1 of the laser light emitted from the light source unit 4 (that is, a light beam cross section perpendicular to the optical axis J 1, hereinafter simply referred to as “cross section”) is caused by the lenses 51 and 52. The image is enlarged at a predetermined magnification.

  FIG. 4 is an enlarged view showing the vicinity of the optical path length difference generation unit 61 and the split lens unit 62. The optical path length difference generation unit 61 includes a plurality of light transmission units 610 arranged densely at a constant pitch in a direction perpendicular to the optical axis J1 (here, the X direction). Each translucent portion 610 is (ideally) in the form of a block having a plane perpendicular to the X direction, the Y direction, and the Z direction. In the plurality of translucent portions 610 arranged in a line in the X direction, the lengths in the X direction and the Y direction are the same, and the lengths in the Z direction, that is, the direction along the optical axis J1, are different from each other. As described above, the plurality of light transmitting portions 610 have different optical path lengths. In the optical path length difference generation unit 61 of FIG. 4, the length in the Z direction is smaller as the light transmission unit 610 located on the (+ X) side among the plurality of light transmission units 610. The length of the plurality of translucent portions 610 in the optical axis J1 direction does not necessarily need to be sequentially increased (or shortened) along the X direction, and may be any uneven shape. In the present embodiment, the plurality of light transmitting parts 610 in the optical path length difference generating part 61 are formed of the same material as a continuous member. In the optical path length difference generation unit 61, a plurality of individually formed light transmission units 610 may be joined to each other.

  In the irradiation optical system 5 of FIG. 2, the lenses 51 and 52 are configured so that approximately the entire cross section of the laser light that has passed through the lenses 51 and 52 is included in the (−Z) side surface of the optical path length difference generation unit 61. The magnification has been adjusted. The light incident on the incident surface 611 that is the (−Z) side surface of each light transmitting portion 610 shown in FIG. 4 is transmitted through the light transmitting portion 610 and is emitted from the output surface 612 that is the (+ Z) side surface. Is done.

  The light that has passed through the optical path length difference generation unit 61 enters the split lens unit 62 via the lenses 641 and 642 of the intermediate zoom unit 64. The intermediate zooming unit 64 constitutes an afocal optical system, specifically, a both-side telecentric optical system, and splits incident light as parallel light parallel to the optical axis J1 as parallel light parallel to the optical axis J1. The light is incident on the part 62. At this time, the cross section perpendicular to the optical axis J1 of the light emitted from the optical path length difference generation unit 61 is reduced by the intermediate magnification unit 64 at a predetermined magnification.

  The split lens unit 62 includes a plurality of lenses 620 (hereinafter referred to as “element lenses 620”) densely arranged at a constant pitch in a direction perpendicular to the optical axis J1 (here, the X direction). In the example of FIG. 4, the number of element lenses 620 in the split lens unit 62 is the same as the number of light transmitting units 610 in the optical path length difference generation unit 61. The arrangement pitch of the element lenses 620 is smaller than the arrangement pitch of the light transmitting parts 610. Each element lens 620 has a long block shape in the Y direction, and a first lens surface 621 that is a side surface located on the (−Z) side (optical path length difference generation unit 61 side) and the (+ Z) side (condensing lens). 2nd lens surface 622 which is a side surface located in the part 63 side). When viewed along the Y direction, the first lens surface 621 has a convex shape protruding toward the (−Z) side, and the second lens surface 622 has a convex shape protruding toward the (+ Z) side. When viewed along the X direction, the shape of each element lens 620 is rectangular. Thus, the element lens 620 is a cylindrical lens having power only in the X direction, and the split lens unit 62 is a so-called cylindrical lens array (or cylindrical fly-eye lens).

  The first lens surface 621 and the second lens surface 622 are symmetrical with respect to a surface perpendicular to the optical axis J1. The first lens surface 621 is disposed at the focal point of the second lens surface 622, and the second lens surface 622 is disposed at the focal point of the first lens surface 621. That is, the focal lengths of the first lens surface 621 and the second lens surface 622 are the same. The plurality of element lenses 620 stacked in the X direction may be formed as a continuous member, or the plurality of element lenses 620 formed individually may be joined to each other.

  As described above, between the optical path length difference generating unit 61 and the split lens unit 62, the intermediate zooming unit 64 constituting the reduction optical system is provided. Further, the reduction magnification M by the intermediate zooming unit 64 is equal to a value obtained by dividing the arrangement pitch R1 of the element lenses 620 in the divided lens unit 62 by the arrangement pitch P1 of the light transmitting units 610 in the optical path length difference generation unit 61 ( That is, (M = R1 / P1)). Accordingly, a plurality of light beams (light bundles) that have passed through the plurality of light transmitting portions 610 are incident on the plurality of element lenses 620 via the intermediate magnification changing portion 64, respectively. In this way, the intermediate magnification unit 64 causes the light beam passing through each light transmitting unit 610 to enter the corresponding element lens 620 while changing its cross-sectional area. The magnification M in the intermediate zoom unit 64 is (M = f2 / f1), where the focal lengths of the two lenses 641 and 642 are f1 and f2, respectively. In the optical path length difference generation unit 61, the number of light transmission units 610 that is one less than the number of element lenses 620 in the split lens unit 62 may be provided. In this case, a plurality of light beams that have passed through these light transmitting portions 610 and a light beam that has not passed through any of the light transmitting portions 610 are incident on the plurality of element lenses 620, respectively.

  As shown in FIG. 4, when viewed along the Y direction, the light incident on the split lens unit 62 is split in the X direction by a plurality of element lenses 620. At this time, parallel light from the lens 642 is incident on the plurality of element lenses 620, and the split light (each of the plurality of light beams) of the second lens surface 622 is such that the principal ray is parallel to the optical axis J1. It is emitted from. The light beams emitted from the element lenses 620 are spread (diverged) and travel toward the condenser lens unit 63 shown in FIG.

  The condenser lens unit 63 has a condenser lens 631. The condenser lens 631 is disposed at a position separated from the second lens surfaces 622 of the plurality of element lenses 620 along the optical axis J1 by the focal length. In other words, the second lens surface 622 of each element lens 620 is disposed on the front focal plane of the condenser lens 631. The irradiation surface 320 disposed on the optical axis J1 is disposed at a position separated from the condenser lens 631 along the optical axis J1 by the focal length of the condenser lens 631. That is, the irradiation surface 320 coincides with the rear focal plane of the condenser lens 631.

  The plurality of light beams emitted from the plurality of element lenses 620 are converted into parallel light by the condenser lens 631 and superimposed on the rear focal plane of the condenser lens 631. That is, the irradiation areas 50 of the light (plural light beams) from the plurality of element lenses 620 are overlapped as a whole. 2 and 3, the irradiation region 50 is indicated by a thick solid line, and the irradiation region 50 has a certain width with respect to the X direction. As described above, since the plurality of light beams emitted from the plurality of element lenses 620 pass through different light transmission units 610, a plurality of light beams are generated between the optical path length difference generation unit 61 and the irradiation surface 320. An optical path length difference occurs. Therefore, interference fringes are suppressed (or prevented) from occurring on the irradiation surface 320 due to interference of light divided by the plurality of element lenses 620. That is, as shown in the upper part of FIG. 5, the light intensity distribution in the X direction is uniform on the irradiation surface 320.

  In each combination of two light transmitting portions 610 among the plurality of light transmitting portions 610, the difference in the optical path length of the light flux passing through the two light transmitting portions 610 is the coherence of the laser light emitted from the light source portion 4. It is preferable that it is more than a distance. If the refractive index of the optical path length difference generation unit 61 is n and the difference in the length of the two light transmission parts 610 in the optical axis J1 direction is d, the difference in the optical path lengths of the light beams passing through the two light transmission parts 610 Is represented as ((n-1) d). Even if the difference in the optical path length of the light passing through each combination of the two light transmitting portions 610 is less than the coherent distance of the laser light emitted from the light source unit 4, a relatively long distance (for example, coherent If the distance is 1/2 or more of the distance, the influence of the interference fringes is reduced to some extent.

  As shown in FIG. 3, when viewed along the X direction, the light incident on the split lens unit 62 from the optical path length difference generation unit 61 via the intermediate zoom unit 64 remains as parallel light and includes a plurality of elements. The light passes through the lens 620 and is guided to the condenser lens 631. The light emitted from the condenser lens 631 is collected on the rear focal plane (irradiation surface 320) of the condenser lens 631. Therefore, on the irradiation surface 320, the irradiation region 50 of the light from each element lens 620 has a line shape extending in the X direction. As a result, line illumination light that is a collection of light that has passed through the plurality of element lenses 620 and has a linear shape with a cross section on the irradiation surface 320 extending in the X direction is obtained. The lower part of FIG. 5 shows the intensity distribution of the line illumination light in the Y direction.

  Here, an irradiation optical system of a comparative example in which the lenses 51 and 52 and the intermediate zoom unit 64 are omitted will be described. FIG. 6 is a diagram showing a configuration of an irradiation optical system 91 of a comparative example. In the irradiation optical system 91 of the comparative example, as in the irradiation optical system 5, the split lens unit 93 is disposed on the irradiation surface side of the optical path length generation unit 92 in the laser beam path. The light beams that have passed through the respective light transmitting portions 920 are irradiated to the split lens portion 93 with the same size. Therefore, it is necessary to make the arrangement pitch P2 of the light transmitting parts 920 in the optical path length difference generation unit 92 equal to the arrangement pitch R1 of the lenses 930 in the divided lens part 93 (that is, (P2 = R1)). A small split lens can be manufactured with high precision using photolithography, but for optical path length difference generating units in which the lengths of a plurality of light transmitting portions in the optical axis direction are different from each other, photolithography is used. It is difficult to use. In addition, it is not easy to manufacture a small optical path length difference generation unit with high precision by machining.

  On the other hand, in the light irradiation device 31 of FIG. 2, the intermediate magnification of the reduction magnification M (where (M <1)) is provided between the optical path length difference generation unit 61 and the split lens unit 62 in the laser beam path. Part 64 is arranged. As a result, the arrangement pitch P1 of the translucent sections 610 in the optical path length difference generation section 61 can be (1 / M) times the arrangement pitch R1 of the element lenses 620 in the split lens section 62, and the irradiation optics of the comparative example It can be made larger than the arrangement pitch P <b> 2 of the light transmitting portions 920 in the system 91. Actually, since the reduction ratio M of the intermediate zooming portion 64 can be adjusted by selecting a lens, the arrangement pitch P1 of the light transmitting portions 610 is not limited by the arrangement pitch R1 of the element lenses 620, and the production conditions It is possible to set arbitrarily according to the above. Thereby, the freedom degree of design of the light irradiation apparatus 31 can be made high. As described above, in the light irradiation device 31, the optical path length difference generation unit 61 can be made larger than the divided lens unit 62 with respect to the arrangement direction of the light transmitting units 610, and the optical path length difference generation unit 61 is easily manufactured. It becomes possible to do.

  Here, it is assumed that the X-direction width of the cross section of the laser light emitted from the light source unit 4 is equal to the X-direction width of the split lens unit 62. In this case, the width W2 (see FIG. 6) in the X direction of the cross section of the laser light emitted from the light source unit 4 is enlarged by (1 / M) times, and the width W1 in the X direction of the optical path length difference generation unit 61 ( 4) (that is, (W1 = (1 / M) · W2)), the lenses 51 and 52 are arranged between the light source unit 4 and the optical path length difference generation unit 61 like the light irradiation device 31 of FIG. Needed in between. Next, the light irradiation device 31 in which such lenses 51 and 52 are omitted will be described.

  7 and 8 are diagrams showing another example of the light irradiation device 31. FIG. FIG. 7 shows the configuration of the light irradiation device 31 viewed along the Y direction, and FIG. 8 shows the configuration of the light irradiation device 31 viewed along the X direction. In the light irradiation device 31 shown in FIGS. 7 and 8, the lenses 51 and 52 are omitted and the polarization beam splitter 55, the quarter wavelength plate 56, and the reflection are omitted as compared with the light irradiation device 31 in FIGS. Part 65 is added. Other configurations are the same as those of the light irradiation device 31 of FIGS. 2 and 3, and the same components are denoted by the same reference numerals.

  7 and 8, the lenses 642, 641, 1 / of the reflection unit 65, the optical path length difference generation unit 61, and the intermediate magnification unit 64 from the (−Z) side toward the (+ Z) direction. These components are arranged in the order of the four-wavelength plate 56, the polarization beam splitter 55, the split lens unit 62, and the condenser lens unit 63. The light source unit 4 is disposed on the (+ X) side of the polarization beam splitter 55. The polarization beam splitter 55 separates the p-polarization component and the s-polarization component, and the laser light emitted from the light source unit 4 enters the polarization beam splitter 55. Most of the laser light incident on the polarization beam splitter 55 is an s-polarized component, and the laser light is reflected by the polarization beam splitter 55 and travels toward the quarter wavelength plate 56. In the quarter-wave plate 56, the laser light that is linearly polarized light is converted into circularly polarized light, and is incident on the lens 641 of the intermediate zoom unit 64. In the intermediate zoom unit 64, the light incident from the (+ Z) side is expanded in cross section and emitted in the (−Z) direction. Since the intermediate zoom unit 64 is configured as a double-sided telecentric optical system, the laser light is incident on the optical path length difference generation unit 61 in the state of parallel light parallel to the optical axis J1.

  The light beam incident on the incident surface 611 which is the (+ Z) side surface of each light transmitting portion 610 is transmitted through the light transmitting portion 610 and is emitted from the emission surface 612 which is the (−Z) side surface. The light beam travels along the optical axis J1 toward the mirror 651 of the reflecting portion 65. The reflection surface of the mirror 651 is perpendicular to the optical axis J1, and the light flux is folded back by the mirror 651 so that it returns along the same path (that is, the traveling direction is rotated by 180 degrees) and enters the same exit surface 612. The light beam incident on the exit surface 612 of each light transmitting portion 610 passes through the light transmitting portion 610 and exits from the entrance surface 611 toward the intermediate magnification varying portion 64.

  In the intermediate zoom unit 64, the light incident from the (−Z) side is reduced in cross section, emitted in the (+ Z) direction, and incident on the quarter-wave plate 56. In the quarter-wave plate 56, circularly polarized light is converted into linearly polarized light, and most of the light incident on the polarizing beam splitter 55 becomes a p-polarized component. The light passes through the polarization beam splitter 55 and enters the split lens unit 62. Also in the light irradiation device 31 of FIG. 7, the plurality of light beams that have passed through the plurality of light transmitting units 610 are incident on the plurality of element lenses 620 via the intermediate magnification unit 64 that constitutes the reduction optical system. The light emitted from the plurality of element lenses 620 enters the condenser lens 631, and the irradiation areas 50 of the light from the plurality of element lenses 620 are superimposed on the irradiation surface 320.

  As described above, in the light irradiation device 31 in FIG. 7, the functions of the lenses 51 and 52 in FIG. 2 function as the intermediate magnification unit 64 in the forward and backward paths of light between the polarization beam splitter 55 and the reflection unit 65. It is realized by. Thereby, the said lenses 51 and 52 are abbreviate | omitted and the full length of the Z direction of the light irradiation apparatus 31 can be shortened. Further, in the return path in the round trip of the light, the light that has passed through the optical path length difference generation unit 61 is guided to the split lens unit 62 by the intermediate magnification unit 64 with its cross section reduced. Thereby, the optical path length difference generation unit 61 can be made larger than the split lens unit 62 with respect to the arrangement direction of the light transmitting units 610, and the optical path length difference generation unit 61 can be easily manufactured. Further, in the optical path length difference generation unit 61, the light emitted from the plurality of emission surfaces 612 of the plurality of light transmission units 610 is folded back by the reflection unit 65 and is incident on the plurality of emission surfaces 612. As described above, the light beams that have passed through the respective light transmitting portions 610 are incident again on the light transmitting portions 610 via the reflecting portions 65, so that the optical path length differences among the plurality of light beams that pass through the plurality of light transmitting portions 610 are reduced. Can be bigger. In other words, the length of the optical path length difference generation unit 61 in the optical axis J1 direction can be shortened.

  In the light irradiation device 31 of FIG. 7, it is possible to relatively reduce the loss of light amount by using the polarization beam splitter 55 and the quarter wavelength plate 56, but depending on the design of the light irradiation device 31. Other beam splitters such as a half mirror may be used. In addition, the quarter wavelength plate 56 can be disposed at an arbitrary position between the polarization beam splitter 55 and the reflection unit 65. The same applies to other light irradiation apparatuses using the polarization beam splitter 55 and the quarter-wave plate 56.

  FIG. 9 is a perspective view showing the optical path length difference generation unit 61. In FIG. 9, parallel oblique lines are attached to the incident surface 611 and the exit surface 612 of one translucent portion 610. Depending on the accuracy in manufacturing the optical path length difference generation unit 61, the parallelism of the incident surface 611 and the exit surface 612 of the light transmitting unit 610 may vary from one light transmitting unit 610 to another.

  FIG. 10 is a diagram showing the light irradiation device 31 in a simplified manner, and shows a part of the light irradiation device 31 viewed along the X direction. In FIG. 10, components provided between the optical path length difference generation unit 61 and the condenser lens 631 of the condenser lens unit 63 are omitted. For example, as indicated by a broken line in FIG. 10, when the incident surface 611 and the exit surface 612 of the light transmitting portion 610 are parallel to each other, the light flux emitted from the exit surface 612 of the light transmitting portion 610 is The light is condensed on the irradiation surface 320 at a position denoted by reference numeral A1. On the other hand, as shown by a solid line in FIG. 10, when the exit surface 612 of the translucent part 610 is inclined with respect to the entrance surface 611 (the entrance surface 611 and the exit surface 612 are not parallel), The light beam emitted from the emission surface 612 of the unit 610 is collected on the irradiation surface 320 at a position denoted by reference numeral A2.

  Here, when viewed along the X direction, the inclination angle of the exit surface 612 with respect to the entrance surface 611 (hereinafter simply referred to as “parallelism”) is θ, the refractive index of the optical path length difference generation unit 61 is n, and the capacitor If the focal length of the lens 631 is fc, the condensing position on the irradiation surface 320 is shifted from the ideal position A1 in the Y direction by (fc · tan ((n−1) θ)). If the parallelism in all the translucent parts 610 is the same, the condensing position of the light beam that has passed through each translucent part 610 is shifted from the ideal position A1 by the same distance. However, in practice, it is difficult to set the parallelism in all the light transmitting portions 610 to 0 or a uniform value, and a certain degree of variation in parallelism occurs. Therefore, the position in the Y direction of the irradiation region (that is, the position in the short axis direction of the line-shaped irradiation region) is shifted for each light transmitting portion 610, and the width of the line illumination light on the irradiation surface 320 in the Y direction is large. Become. Therefore, when the variation in parallelism among the plurality of light transmitting units 610 increases, the pattern drawing accuracy in the drawing apparatus 1 may decrease. Next, a method for suppressing the influence of variations in parallelism in the plurality of light transmitting portions 610 will be described.

  11 and 12 are diagrams illustrating another example of the light irradiation device 31. FIG. FIG. 11 shows the configuration of the light irradiation device 31 viewed along the Y direction, and FIG. 12 shows the configuration of the light irradiation device 31 viewed along the X direction. In the light irradiation device 31 shown in FIGS. 11 and 12, a right-angle prism 652 is provided instead of the mirror 651 in the light irradiation device 31 of FIGS. Other configurations are the same as those of the light irradiation device 31 of FIGS. 7 and 8, and the same reference numerals are given to the same configurations.

  As shown in FIG. 12, in the right-angle prism 652, two surfaces 652a and 652b forming 90 degrees are aligned in the Y direction, and both the surfaces 652a and 652b are inclined by 45 degrees with respect to the optical axis J1. A light beam transmitted through the light transmitting portion 610 shown in FIG. 11 and emitted from the emission surface 612 is reflected by one of the two surfaces 652a and 652b in the right-angle prism 652 shown in FIG. The light is further reflected on the other surface and enters the light transmitting portion 610. Actually, when viewed along the X direction, the entire luminous flux emitted from the exit surface 612 of each light transmitting portion 610 is relative to the optical axis J1 according to the parallelism of the entrance surface 611 and the exit surface 612. Then, the light enters the right-angle prism 652 along the inclined path (the path parallel to the optical axis J1 when the parallelism is 0), and returns to the exit surface 612 of the translucent portion 610 along the same path. Therefore, the light beam incident on the incident surface 611 of each light transmitting unit 610 in parallel with the optical axis J1 from the lens 642 of the intermediate magnification varying unit 64 passes through the right-angle prism 652 and travels from the incident surface 611 toward the lens 642. The light is emitted parallel to the axis J1.

  Thus, in the light irradiation apparatus 31 shown in FIG. 12, the reflection part 65 makes the light radiate | emitted from the output surface 612 of each translucent part 610 inject into the said output surface 612 in parallel with the output direction of the said light. . Thereby, even if the parallelism in the plurality of light transmitting portions 610 varies, the inclinations (X direction) of the plurality of light beams emitted from the plurality of light transmitting portions 610 toward the intermediate magnification varying portion 64 side with respect to the optical axis J1. Can be made to coincide with the inclination (ideally, parallel to the optical axis J1) at the time of incidence from the intermediate zoom unit 64 to the optical path length difference generator 61. As a result, the deviation in the Y direction of the condensing position (condensing position when viewed along the X direction) on the irradiation surface 320 of the plurality of light fluxes that have passed through the plurality of light transmitting portions 610 is suppressed, and the irradiation surface 320. It is possible to suppress an increase in the width of the line illumination light in the Y direction. In the reflecting section 65, instead of the right-angle prism 652, two plane mirrors having an angle of 90 degrees with each other may be used.

  By the way, when using the right-angle prism 652 in the reflection part 65 like the light irradiation apparatus 31 shown in FIG. 12, the light beam radiate | emitted from each light transmission part 610 toward the reflection part 65 reflects on the surface 652a first. It is divided into a light beam group and a light beam group that is first reflected by the surface 652b. Therefore, when the angle formed by the surface 652a and the surface 652b is deviated from 90 degrees in the right-angle prism 652, the condensing position on the irradiation surface 320 of these light ray groups is deviated in the Y direction. Next, a method for suppressing the influence of the variation in parallelism in the plurality of light transmitting parts 610 without dividing the light beam emitted from each light transmitting part 610 will be described.

  13 and 14 are diagrams showing another example of the light irradiation device 31. FIG. FIG. 13 shows the configuration of the light irradiation device 31 viewed along the Y direction, and FIG. 14 shows the configuration of the light irradiation device 31 viewed along the X direction. In the light irradiation device 31 shown in FIGS. 13 and 14, the quarter wavelength plate 56 is omitted as compared with the light irradiation device 31 in FIGS. 7 and 8 (and the light irradiation device 31 in FIGS. 11 and 12). In addition, the configuration of the reflecting portion 65 is different. Other configurations are the same as those of the light irradiation device 31 of FIGS. 7 and 8, and the same reference numerals are given to the same configurations.

  The reflection unit 65 includes a polarization beam splitter 653, three mirrors 654a, 654b, and 654c, and a half-wave plate 655. The polarization beam splitter 653 is disposed on the (−Z) side of the optical path length difference generation unit 61 and reflects the s-polarized component of the light incident from the optical path length difference generation unit 61 in the (−Y) direction. One mirror 654a is disposed on the (−Y) side of the polarizing beam splitter 653, and the other mirror 654b is disposed on the (−Y) side and the (−Z) side of the polarizing beam splitter 653, and the remaining mirror 654c. Is disposed on the (−Z) side of the polarizing beam splitter 653. The normal lines of the reflecting surfaces of the three mirrors 654a to 654c are perpendicular to the X direction, and the mirrors 654a and 654c are inclined 90 degrees with respect to the mirror 654b.

  The light traveling from the polarization beam splitter 653 toward the (−Y) direction is sequentially reflected by the mirrors 654a and 654b and enters the mirror 654c. In the mirror 654 c, incident light is reflected in the (+ Z) direction and travels toward the polarization beam splitter 653. The half-wave plate 655 is disposed between the mirror 654c and the polarization beam splitter 653. In the half-wave plate 655, the polarization direction of the light is rotated by 90 degrees, and most of the light incident on the polarization beam splitter 55 becomes a p-polarized component. The light passes through the polarization beam splitter 653 and enters the optical path length difference generation unit 61. Actually, in the reflection unit 65, the path of the light beam emitted from the emission surface 612 of each translucent unit 610 is folded in a plane perpendicular to the X direction (a plane parallel to the minor axis direction of the irradiation region), A light beam is incident on the emission surface 612.

  FIG. 15 is an enlarged view showing the vicinity of the reflecting portion 65, and shows the reflecting portion 65 viewed along the X direction. When the incident surface 611 and the exit surface 612 of the light transmitting portion 610 are parallel, that is, when the parallelism is 0, the light beam emitted from the exit surface 612 of the light transmitting portion 610 is a broken line in FIG. The route K1 shown by is passed. In this case, the light beam incident on the incident surface 611 of the light transmitting unit 610 along the path K1 from the intermediate zoom unit 64 ((+ Z) side) passes through the reflecting unit 65 and is incident from the incident surface 611. The light is emitted in the (+ Z) direction along the same path K1.

  On the other hand, when the parallelism of the translucent part 610 is not 0, the light beam emitted from the exit surface 612 of the translucent part 610 passes the path K2 indicated by the solid line in FIG. Specifically, the light beam incident on the incident surface 611 of the light transmitting unit 610 along the path K1 from the intermediate magnification changing unit 64 ((+ Z) side) enters the path K1 from the emission surface 612 of the light transmitting unit 610. The light is emitted toward the polarization beam splitter 653 along the emission direction (direction of the path K2) inclined with respect to the direction. The light beam is reflected four times by the polarization beam splitter 653 and the three mirrors 654a to 654c, and is incident on the emission surface 612 in parallel with the emission direction at the time of emission from the emission surface 612. Therefore, the light beam that has passed through the light transmitting portion 610 is emitted in the (+ Z) direction from the incident surface 611 in parallel with the path K1 at the time of incidence.

  In the light irradiation device 31 of FIG. 14, the light incident on the optical path length difference generation unit 61 from the intermediate magnification changing unit 64 is parallel light parallel to the optical axis J1, and as described above, the light transmitted from the plurality of light transmission units 610 is parallel. Even when the degrees vary, the light beam emitted in the (+ Z) direction from the incident surfaces 611 of the plurality of light transmitting parts 610 via the reflecting part 65 becomes parallel light parallel to the optical axis J1. Therefore, the condensing positions on the irradiation surface 320 of the plurality of light beams that have passed through the plurality of light transmitting portions 610 can be matched with the Y direction.

  As described above, in the light irradiation device 31 illustrated in FIG. 14, the reflection unit 65 does not divide the light beam emitted from the emission surface 612 of each light transmission unit 610, and the output is parallel to the emission direction of the light beam. The light can enter the surface 612. Thereby, even if the parallelism in the plurality of light transmitting portions 610 varies, the deviation in the Y direction of the condensing position on the irradiation surface 320 of the plurality of light beams that have passed through the plurality of light transmitting portions 610 is suppressed (reduced). )can do. The reflection unit 65 may be configured to reflect and return the incident light even times. The reflection unit 65 reflects the light even number of times six or more times and returns to the optical path length difference generation unit 61. Also good. Further, the reflection unit 65 that reflects the light even times and turns the light back may be realized by using various optical elements such as a prism.

  16 and 17 are diagrams showing another example of the light irradiation device 31. FIG. FIG. 16 shows the configuration of the light irradiation device 31 viewed along the Y direction, and FIG. 17 shows the configuration of the light irradiation device 31 viewed along the X direction. In the light irradiation apparatus 31 shown in FIGS. 16 and 17, a cylindrical lens 656 is added between the optical path length difference generation unit 61 and the mirror 651 as compared with the light irradiation apparatus 31 in FIGS. 7 and 8. Is different. Other configurations are the same as those of the light irradiation device 31 of FIGS. 7 and 8, and the same reference numerals are given to the same configurations.

  The cylindrical lens 656 has power only in the Y direction, and the reflection surface of the mirror 651 is disposed at a position away from the cylindrical lens 656 along the optical axis J1 by the focal length of the cylindrical lens 656. Accordingly, when viewed along the X direction, the light incident on the optical path length difference generation unit 61 in the state of parallel light parallel to the optical axis J1 is transmitted through the optical path length difference generation unit 61 and is transmitted by the cylindrical lens 656. The light is condensed on the reflection surface of the mirror 651. The light is reflected by the mirror 651, converted into parallel light by the cylindrical lens 656, and enters the optical path length difference generation unit 61.

  FIG. 18 is an enlarged view showing the vicinity of the reflecting portion 65, and shows the reflecting portion 65 viewed along the X direction. When the parallelism of the translucent part 610 is not 0, the light beam incident on the incident surface 611 of the translucent part 610 as parallel light parallel to the optical axis J1 is shown as a broken line in FIG. The light is emitted as parallel light in the emission direction inclined with respect to the optical axis J1 from the emission surface 612 of the optical unit 610. The luminous flux is condensed at a position shifted from the optical axis J 1 on the mirror 651 by the action of the cylindrical lens 656. As indicated by a solid line in FIG. 18, the light beam reflected by the mirror 651 is converted into parallel light parallel to the emission direction by the cylindrical lens 656 and enters the emission surface 612 of the translucent portion 610. Therefore, the light beam transmitted through the light transmitting portion 610 is emitted in the (+ Z) direction from the incident surface 611 in parallel with the path when entering the light transmitting portion 610 from the (+ Z) side.

  As described above, also in the light irradiation device 31 shown in FIG. 17, the light emitted from the emission surface 612 of each light transmitting part 610 is divided in parallel with the light emission direction by the reflecting part 65 without dividing the light. The light can enter the light exit surface 612. Thereby, even if the parallelism in the some translucent part 610 varies, the shift | offset | difference of the Y direction of the condensing position on the irradiation surface 320 of the light which passed the some translucent part 610 can be suppressed. .

  19 and 20 are diagrams showing a configuration of a light irradiation apparatus 31a according to the second embodiment of the present invention. FIG. 19 shows the configuration of the light irradiation device 31a viewed along the Y direction, and FIG. 20 shows the configuration of the light irradiation device 31a viewed along the X direction.

  19 and 20 includes a light source unit 40 and an irradiation optical system 5a. The light source unit 40 includes a plurality of light source units 4, and each light source unit 4 includes one light source 41 and one collimator lens 42. The light sources 41 of the plurality of light source units 4 are arranged approximately in the X direction on a plane parallel to the ZX plane (hereinafter referred to as “light source arrangement plane”). The laser light emitted from each light source 41 is collimated by the collimator lens 42 and enters the irradiation optical system 5a. The light source unit 40 is provided with a mechanism (not shown) that adjusts the emission direction of the laser light emitted from the light source unit 4. By adjusting the mechanism, it is possible to match the positions on the irradiation optical system 5a to which the laser beams from the plurality of light source units 4 are irradiated. As described above, in the light source unit 40, the plurality of light source units 4 arranged on the light source arrangement surface are moved from the different directions along the light source arrangement surface to the same position on the irradiation optical system 5a (divided lens unit 62 described later). A laser beam is emitted.

  The irradiation optical system 5a includes an optical path length difference generation unit 61, a split lens unit 62, a condensing lens unit 63, and an intermediate zoom unit 64a. In the irradiation optical system 5a, from the light source unit 40 toward the irradiation surface 320, the divided lens unit 62, the intermediate zoom unit 64a, the optical path length difference generation unit 61, and the condensing lens unit 63 are arranged in this order in the order of the optical axis J1. It is arranged along. The collimated laser beams from the plurality of light source units 4 enter the split lens unit 62. As shown in FIG. 21, in the split lens unit 62, a plurality of element lenses 620 are arranged in the X direction perpendicular to the optical axis J1 of the irradiation optical system 5a and along the light source arrangement surface.

  When viewed along the Y direction, light incident on the split lens unit 62 is split by the plurality of element lenses 620 in the X direction. At this time, parallel light from each light source unit 4 enters the first lens surface 621 of each element lens 620, and images of the plurality of light sources 41 are formed in the vicinity of the second lens surface 622. These images are arranged in the arrangement direction of the element lenses 620. Note that FIG. 21 shows only light rays incident on one element lens 620.

  The light (plural light beams) divided by the plurality of element lenses 620 is emitted from the second lens surface 622 so that the principal ray is parallel to the optical axis J1. The light beam emitted from each element lens 620 spreads and enters the lens 643 of the intermediate zoom unit 64a shown in FIG. 19 and enters the optical path length difference generation unit 61 via the lenses 643 and 644. In the optical path length difference generation unit 61, a plurality of light transmission units 610 are arranged in the X direction perpendicular to the optical axis J1 of the irradiation optical system 5a and along the light source arrangement surface. The arrangement pitch of the light transmitting portions 610 is larger than the arrangement pitch of the element lenses 620.

  The intermediate zooming unit 64a constitutes an afocal optical system, specifically, a double-sided telecentric optical system, and the principal ray is incident in a state parallel to the optical axis J1, and the principal ray is parallel to the optical axis J1. In this state, the light is incident on the optical path length difference generation unit 61. At this time, the intermediate zooming unit 64a converts the image of the second lens surface 622 that is the exit surface of the plurality of element lenses 620 (specifically, the image of the plurality of light sources 41 on the second lens surface 622) to the optical path length difference. It is enlarged and formed inside or near the generator 61.

  Specifically, the magnification by the intermediate zooming unit 64 a is equal to a value obtained by dividing the arrangement pitch of the light transmitting units 610 in the optical path length difference generation unit 61 by the arrangement pitch of the element lenses 620 in the divided lens unit 62. Accordingly, the light (plural light beams) that has passed through the plurality of element lenses 620 is incident on the plurality of light transmitting portions 610 via the intermediate magnification varying portion 64a that constitutes the magnifying optical system. At this time, images of the second lens surfaces 622 of the plurality of element lenses 620 are formed in or near the plurality of light transmitting portions 610, respectively. In addition, the divergence angle of the light beam emitted from each element lens 620 in the translucent portion 610 is smaller than the divergence angle in the vicinity of the second lens surface 622 of the element lens 620 according to the magnification. As a result, the light flux is less likely to be applied to the edge of the translucent portion 610 (that is, the end in the X direction, mainly the edges on the entrance surface 611 and the exit surface 612). The light flux that has passed through each light transmitting portion 610 travels toward the condensing lens portion 63. The plurality of light beams emitted from the plurality of light transmitting portions 610 are converted into parallel light by the condenser lens 631 of the condenser lens portion 63 and are superimposed on the irradiation surface 320. That is, the irradiation areas 50 of light (a plurality of light beams) from the plurality of light transmitting portions 610 are entirely overlapped.

  As shown in FIG. 20, when viewed along the X direction, the light incident on the optical path length difference generation unit 61 from the light source unit 40 via the split lens unit 62 and the intermediate zoom unit 64a remains as parallel light. Then, the light passes through the plurality of light transmitting portions 610 and is guided to the condenser lens 631. The light emitted from the condenser lens 631 is collected on the irradiation surface 320. Therefore, on the irradiation surface 320, the irradiation region 50 of light from each element lens 620 (translucent portion 610) has a line shape extending in the arrangement direction. That is, the cross section of the light irradiated onto the irradiation surface 320 by the light irradiation device 31a becomes a line extending in the X direction, and line illumination light is obtained.

  In the light irradiation device 31a, the condenser lens 631 is a spherical lens. For example, by adding a cylindrical lens having power only in the Y direction to the condenser lens unit 63, a desired width in the Y direction on the irradiation surface 320 can be obtained. A line illumination light may be obtained. When the light source 41 is a high-power semiconductor laser and the laser light emitted from the light source 41 is multimode in one direction, the direction in which the single mode is set is the arrangement of the element lenses 620 in the split lens unit 62. It is preferable to match the direction perpendicular to the direction (Y direction). This prevents the width of the line illumination light in the Y direction from being widened on the irradiation surface 320.

  As described above, in the light irradiation device 31a of FIG. 19, the optical path length difference generation unit 61 is arranged on the irradiation surface 320 side with respect to the split lens unit 62 in the laser beam path, and the optical path length difference from the split lens unit 62 Between the generating unit 61, an intermediate zooming unit 64a constituting the magnifying optical system is arranged. Accordingly, the optical path length difference generation unit 61 can be made larger than the split lens unit 62 with respect to the arrangement direction of the light transmitting units 610 (X direction in FIG. 19), and the optical path length difference generation unit 61 is easily manufactured. can do.

  In the light irradiation device 31 a, laser light is emitted from the plurality of light source units 4 toward the split lens unit 62. Thereby, compared with the light irradiation apparatus in which only one light source part 4 is used, high intensity | strength line illumination light can be obtained. In addition, since the phases of the laser beams from the plurality of light source units 4 are different from each other, this is combined with the provision of optical path length differences to the plurality of light beams passing through the plurality of element lenses 620 by the plurality of light transmitting units 610. Thus, the uniformity of the intensity distribution of the line illumination light on the irradiation surface 320 can be further improved.

  By the way, when the light that has passed through each element lens of the split lens unit is applied to the edge of the translucent unit (such as a boundary between the translucent units) in the optical path length difference generating unit, the light is scattered and the light on the irradiation surface is scattered. The uniformity of the intensity distribution is reduced. Assuming a comparative light irradiating device that omits the intermediate zooming unit 64a between the split lens unit 62 and the optical path length difference generating unit 61, it passes through the element lens by increasing the arrangement pitch of the translucent units. It is conceivable to prevent the transmitted light from being applied to the edge of the translucent part. However, in order to increase the arrangement pitch of the translucent portions in the light irradiation device of the comparative example, it is necessary to increase the arrangement pitch of the element lenses in the division lens portion, which makes it difficult to produce a division lens portion using photolithography. Become.

  On the other hand, in the light irradiation device 31a, as described above, the intermediate power changing unit 64a constituting the magnifying optical system is provided between the split lens unit 62 and the optical path length difference generating unit 61, so that the optical path The arrangement pitch of the light transmitting parts 610 in the length difference generation unit 61 can be made larger than the arrangement pitch of the element lenses 620 in the divided lens part 62. Further, the intermediate magnification unit 64a forms an image of the exit surface of the plurality of element lenses 620 in or near the plurality of light transmitting parts 610, and the light is emitted from each element lens 620 as the image is enlarged. The divergence angle of the transmitted light beam in the translucent part 610 is smaller than the divergence angle in the element lens 620. As a result, it is possible to easily suppress the light flux from being applied to the edge of the light transmitting portion 610, and to ensure the uniformity of the intensity distribution of the light irradiated onto the irradiation surface 320 by the light irradiation device 31a. can do.

  22 and 23 are diagrams showing another example of the light irradiation device 31a. FIG. 22 shows the configuration of the light irradiation device 31a viewed along the Y direction, and FIG. 23 shows the configuration of the light irradiation device 31a viewed along the X direction. In the light irradiation device 31a shown in FIGS. 22 and 23, as compared with the light irradiation device 31a in FIGS. 19 and 20, lenses 53 and 54 are added between the optical path length difference generation unit 61 and the condenser lens unit 63. Is different. Other configurations are the same as those of the light irradiation device 31a of FIGS. 19 and 20, and the same components are denoted by the same reference numerals.

  The lenses 53 and 54 constitute a reduction optical system (for example, both-side telecentric optical system), and an image of the second lens surface 622 of the plurality of element lenses 620 (see FIG. 21) in or near the optical path length difference generation unit 61. In detail, the reduction relay is performed on the images of the plurality of light sources 41 on the second lens surface 622. The light emitted from the lens 54 enters the condenser lens 631 of the condenser lens unit 63, and a line-shaped irradiation region 50 is formed on the irradiation surface 320.

  As described above, the light beam emitted from each element lens 620 has a relatively small divergence angle in the light transmitting portion 610, so that the light irradiation device 31a can easily apply the light flux to the edge of the light transmitting portion 610. It is suppressed. In this case, in order to obtain line illumination light having a certain length in the X direction on the irradiation surface 320, it is necessary to provide the condenser lens 631 having a long focal length in the light irradiation device 31a of FIG. The overall length of the irradiation optical system 5a is increased. On the other hand, in the light irradiation device 31a of FIG. 22, the lenses 53 and 54 constituting the reduction optical system are provided between the optical path length difference generation unit 61 and the condenser lens unit 63, so that the irradiation optical system 5a. Can be made relatively short, and the light irradiation device 31a can be downsized.

  24 and 25 are diagrams showing another example of the light irradiation device 31a. FIG. 24 shows the configuration of the light irradiation device 31a viewed along the Y direction, and FIG. 25 shows the configuration of the light irradiation device 31a viewed along the X direction. The light irradiation device 31a shown in FIGS. 24 and 25 is different from the light irradiation device 31a shown in FIGS. 19 and 20 in that a polarizing beam splitter 55, a quarter wavelength plate 56, and a reflection unit 65 are added. To do. Other configurations are the same as those of the light irradiation device 31a of FIGS. 19 and 20, and the same components are denoted by the same reference numerals.

  In the light irradiation device 31a of FIG. 24, the lens 644 of the reflection unit 65, the optical path length difference generation unit 61, the quarter wavelength plate 56, and the intermediate magnification unit 64a from the (−Z) side toward the (+ Z) direction. These components are arranged in the order of 643, the polarization beam splitter 55, and the condenser lens unit 63. The light source unit 40 is disposed on the (+ X) side of the polarization beam splitter 55, and the split lens unit 62 is disposed between the light source unit 40 and the polarization beam splitter 55. In the light source unit 40, laser light is emitted from the plurality of light source units 4 arranged approximately in the Z direction toward the split lens unit 62 along different directions parallel to the light source array surface.

  In the split lens unit 62, a plurality of element lenses 620 (see FIG. 21) are arrayed in the Z direction perpendicular to the optical axis between the light source unit 40 and the polarization beam splitter 55 and along the light source array plane. Light incident on 62 is split in the Z direction. The light that has passed through the split lens unit 62 enters the polarization beam splitter 55 in a state in which the principal ray is parallel to the X direction. The polarization beam splitter 55 separates the p-polarized component and the s-polarized component. Most of the light that enters the polarization beam splitter 55 from the light source unit 40 via the split lens unit 62 is an s-polarized component, and the light is reflected by the polarization beam splitter 55 and is directed to the lens 643 of the intermediate magnification unit 64a. Head. At this time, the arrangement direction of the plurality of light beams emitted from the plurality of element lenses 620 is converted into the X direction. In other words, the chief ray of the light traveling from the polarization beam splitter 55 to the intermediate zoom unit 64a is parallel to the Z direction.

  In the intermediate zooming unit 64a, a double-sided telecentric optical system is configured, and the optical path length in which the principal ray is incident in a state parallel to the optical axis J1 (Z direction) and the principal ray is parallel to the optical axis J1. The light is incident on the difference generator 61. Actually, the light (a plurality of light fluxes) that has passed through the plurality of element lenses 620 passes through the polarization beam splitter 55, the intermediate magnification varying portion 64a, and the quarter wavelength plate 56, and thus the plurality of light transmitting portions arranged in the X direction. An image of the second lens surface 622 of each of the plurality of element lenses 620 (an image of the light source 41) is formed to be enlarged inside or in the vicinity of the plurality of light transmitting portions 610 in the optical path length difference generation unit 61. Is done. As described above, the arrangement direction of the element lenses 620 of the split lens unit 62 corresponds to the arrangement direction of the light transmission units 610 of the optical path length difference generation unit 61 via the polarization beam splitter 55.

  The reflection unit 65 includes a reflection film 651 a formed by coating on the (−Z) side surface of the optical path length difference generation unit 61. The light beam incident on the incident surface 611 (see FIG. 4) on the (+ Z) side of each light transmitting portion 610 is reflected by the reflection film 651a on the emission surface 612 on the (−Z) side. The light is emitted from the incident surface 611. That is, the light beam incident on the incident surface 611 of each light transmitting portion 610 reciprocates in the Z direction inside the light transmitting portion 610 and is emitted from the incident surface 611 in the (+ Z) direction. The reflective film 651 a on the emission surface 612 substantially folds the light emitted from the plurality of emission surfaces 612 of the plurality of light transmitting portions 610 and makes each incident on the plurality of emission surfaces 612. The image of the second lens surface 622 of the element lens 620 is preferably formed in the vicinity of the emission surface 612 (in the vicinity of the reflective film 651a) of the light transmitting portion 610.

  The light emitted from the optical path length difference generation unit 61 in the (+ Z) direction is incident on the intermediate magnification unit 64 a via the quarter-wave plate 56. In the intermediate zooming unit 64a, the images of the exit surfaces of the plurality of element lenses 620 in or near the optical path length difference generating unit 61 are reduced and relayed. Light emitted from the lens 643 enters the polarization beam splitter 55. The light incident on the polarization beam splitter 55 from the intermediate magnification varying portion 64a becomes a p-polarized component by passing through the quarter-wave plate 56 twice by the reciprocation between the polarization beam splitter 55 and the reflection portion 65. The light passes through the polarization beam splitter 55 and enters the condenser lens 631. Then, the irradiation area 50 of the light from the plurality of element lenses 620 is superimposed on the irradiation surface 320 by the condenser lens 631.

  As described above, in the light irradiation device 31a in FIG. 24, an image obtained by enlarging the exit surfaces of the plurality of element lenses 620 is intermediate in the forward path of light between the polarization beam splitter 55 and the reflection unit 65. It is formed inside or in the vicinity of the plurality of light transmitting parts 610 by the zooming part 64a. Thereby, the optical path length difference generation unit 61 can be made larger than the split lens unit 62 with respect to the arrangement direction of the light transmitting units 610, and the optical path length difference generation unit 61 can be easily manufactured. Further, the functions of the lenses 53 and 54 in FIG. 22 are realized by the intermediate magnification changing unit 64a in the return path in the light reciprocation, thereby omitting the lenses 53 and 54 and the total length of the light irradiation device 31a in the Z direction. Can be shortened. Further, the light beam passing through each light transmitting section 610 reciprocates the light transmitting section 610, thereby shortening the length of the optical path length difference generating section 61 in the optical axis J1 direction (for example, the optical paths in FIGS. 19 and 22). Half the length of the length difference generator 61). In the light irradiation device 31a of FIG. 24, a mirror 651 shown in FIG. 7 may be provided instead of the reflective film 651a. Similarly, in the light irradiation device 31 of FIG. 7, a reflective film 651 a may be provided instead of the mirror 651.

  26 and 27 are diagrams showing another example of the light irradiation device 31a. FIG. 26 shows the configuration of the light irradiation device 31a viewed along the Y direction, and FIG. 27 shows the configuration of the light irradiation device 31a viewed along the X direction. In the light irradiation device 31a shown in FIGS. 26 and 27, a lens 657 and a right-angle prism 658 are provided instead of the reflective film 651a in the light irradiation device 31a of FIGS. Other configurations are the same as those of the light irradiation device 31a of FIGS. 24 and 25, and the same components are denoted by the same reference numerals.

  The lens 657 of the reflection unit 65 is located at a position (−Z) away from the position where the image of the exit surface of the element lens 620 (see FIG. 21) is formed in the optical path length difference generation unit 61 by the focal length of the lens 657. Placed in. Therefore, the light beam emitted from the emission surface 612 that is the (−Z) side surface of each light transmitting portion 610 toward the lens 657 is emitted by the lens 657 to the (−Z) side as parallel light. The right-angle prism 658 is disposed at a position away from the lens 657 by the focal length of the lens 657 toward the (−Z) side. As shown in FIG. 26, when viewed along the Y direction, each light ray incident on the right-angle prism 658 is reflected by one of the two surfaces 658a and 658b forming 90 degrees and travels toward the other surface. The light is further reflected on the other surface and travels toward the lens 657 in parallel with the path upon incidence on the right-angle prism 658. The light that enters the lens 657 from the (−Z) side enters the optical path length difference generation unit 61 while converging. Actually, the light beam emitted from the (−Z) side emission surface 612 of each light transmitting portion 610 is folded back by the reflection portion 65 and returns to the same emission path 612 after entering the same path. Further, a condensing point of the light flux is formed in or near the light transmitting portion 610.

  The light emitted from the optical path length difference generation unit 61 in the (+ Z) direction is incident on the polarization beam splitter 55 via the quarter-wave plate 56 and the intermediate magnification unit 64a. The light passes through the polarization beam splitter 55 and enters the condenser lens 631. Then, the irradiation area 50 of the light from the plurality of element lenses 620 is superimposed on the irradiation surface 320 by the condenser lens 631.

  Here, as shown in FIG. 27, it is assumed that the parallelism of the incident surface 611 and the exit surface 612 of the light transmitting portion 610 varies in each light transmitting portion 610 when viewed along the X direction. In this case, the light beam incident on the (+ Z) side incident surface 611 of each light transmitting portion 610 as parallel light parallel to the optical axis J1 is inclined with respect to the optical axis J1 from the emission surface 612 of the light transmitting portion 610. It is emitted as parallel light in the emitted direction. The luminous flux is condensed at a position shifted from the optical axis J1 on the right-angle prism 658 by the action of the lens 657. The light beam reflected by the right-angle prism 658 is converted into parallel light parallel to the emission direction by the lens 657 and is incident on the emission surface 612 of the translucent portion 610. Therefore, the light beam that has passed through the light transmitting portion 610 does not depend on the degree of parallelism of the light transmitting portion 610, and is (+ Z) from the incident surface 611 in parallel to the path when entering the light transmitting portion 610 from the (+ Z) side. ) Direction. Then, the light irradiation regions 50 from the plurality of light transmitting portions 610 are formed on the irradiation surface 320 at (substantially) the same position in the Y direction.

  As described above, in the light irradiation device 31a shown in FIG. 26 and FIG. 27, the reflection unit 65 causes the light emitted from the emission surface 612 of each light transmission unit 610 to be parallel to the emission direction of the light. 612 is incident. Thereby, even when the parallelism (wedge component) in the plurality of light transmitting portions 610 varies, the inclinations (X of the plurality of light beams emitted from the plurality of light transmitting portions 610 in the (+ Z) direction with respect to the optical axis J1 (X The inclination when viewed along the direction) can be made to coincide with the inclination (ideally parallel to the optical axis J1) at the time of incidence on the optical path length difference generation unit 61 from the (+ Z) side. As a result, the deviation in the Y direction of the condensing position (condensing position when viewed along the X direction) on the irradiation surface 320 of the plurality of light fluxes that have passed through the plurality of light transmitting portions 610 is suppressed, and the irradiation surface 320. It is possible to suppress an increase in the width of the line illumination light in the Y direction. In the reflecting portion 65, instead of the right-angle prism 658, two plane mirrors having an angle of 90 degrees with each other may be used.

  The drawing apparatus 1 and the light irradiation apparatuses 31 and 31a can be variously modified.

  In the split lens unit 62, the plurality of element lenses 620 are not necessarily arranged at a constant pitch in the arrangement direction. For example, the widths of the plurality of element lenses 620 in the arrangement direction may be different from each other. In this case, with respect to the arrangement direction, the ratio of the width of each light transmitting unit 610 in the optical path length difference generating unit 61 to the width of the element lens 620 of the divided lens unit 62 corresponding to the light transmitting unit 610 is all the light transmitting units. The width in the arrangement direction of the plurality of light transmitting parts 610 is also changed so as to be constant in the part 610.

  Depending on the design of the light irradiation devices 31 and 31 a, an element lens 620 having power not only in the arrangement direction of the element lenses 620 but also in a direction perpendicular to the arrangement direction may be used in the split lens unit 62.

  For example, in the light irradiation device 31 of FIG. 2, even if the light emitted from the lens 642 of the intermediate zoom unit 64 enters the split lens unit 62 in a state where the principal ray is inclined with respect to the optical axis J1. Good. That is, the intermediate zooming portions 64 and 64a do not necessarily need to be double-sided telecentric optical systems. In the irradiation optical system 5 in which the split lens unit 62 is arranged on the irradiation surface 320 side of the optical path length difference generation unit 61 in the laser beam path, the intermediate magnification changing unit 64 is configured to transmit the light that has passed through the plurality of light transmission units 610. A reduction optical system that enters each of the plurality of element lenses 620 may be configured. In the irradiation optical system 5a in which the optical path length difference generation unit 61 is disposed on the irradiation surface 320 side of the split lens unit 62 in the laser beam path, the intermediate magnification changing unit 64a is light that has passed through the plurality of element lenses 620. May be configured to constitute a magnifying optical system that respectively enters the plurality of light transmitting portions 610.

  In the path of the laser light in the light irradiation devices 31 and 31a, the condensing lens unit 63 disposed on the irradiation surface 320 side with respect to the split lens unit 62 and the optical path length difference generation unit 61 has a plurality of on the irradiation surface 320. If it is possible to overlap the irradiation region 50 of the light from the element lens 620, it may be realized in various configurations.

  In the drawing apparatus 1, the spatial light modulator 32 disposed on the irradiation surface 320 of the light irradiation device 31, 31 a may be other than a diffraction grating type light modulator, for example, a space using a set of minute mirrors. An optical modulator may be used. In this case, an irradiation region having a relatively wide width in the Y direction may be formed on the irradiation surface 320 by the light irradiation devices 31 and 31a.

  The moving mechanism for moving the light irradiation position on the substrate 9 may be other than the moving mechanism 22 for moving the stage 21. For example, the light irradiation devices 31, 31a, the spatial light modulator 32, and the projection optical system 33 are included. It may be a moving mechanism that moves the head including the substrate 9.

  An object on which drawing is performed by the drawing apparatus 1 may be a substrate other than a semiconductor substrate or a glass substrate, or may be other than a substrate. The light irradiation devices 31 and 31 a may be used in addition to the drawing device 1.

  The configurations in the above-described embodiments and modifications may be combined as appropriate as long as they do not contradict each other.

DESCRIPTION OF SYMBOLS 1 Drawing apparatus 4 Light source part 5, 5a Irradiation optical system 9 Substrate 11 Control part 22 Movement mechanism 31, 31a Light irradiation apparatus 32 Spatial light modulator 33 Projection optical system 50 Irradiation area 61 Optical path length difference generation part 62 Split lens part 63 Collection Optical lens part 64, 64a Intermediate magnification changing part 65 Reflecting part 320 Irradiation surface 610 Translucent part 612 Emission surface (of translucent part) 620 Element lens 622 Second lens surface J1 Optical axis

Claims (8)

A light irradiation device,
A light source unit that emits laser light toward a predetermined position;
An irradiation optical system that is disposed at the predetermined position and guides the laser light from the light source unit to the irradiation surface along the optical axis;
With
The irradiation optical system is
A plurality of lenses arranged in a direction perpendicular to the optical axis, and a split lens unit that splits incident light by the plurality of lenses;
An optical path length difference generating unit having a plurality of light transmitting parts arranged in a direction perpendicular to the optical axis, wherein the plurality of light transmitting parts have different optical path lengths;
An intermediate magnification unit disposed between the split lens unit and the optical path length difference generation unit in the laser beam path;
A condensing lens unit that is disposed on the irradiation surface side of the split lens unit and the optical path length difference generation unit in the laser beam path, and overlaps the irradiation regions of the light from the plurality of lenses on the irradiation surface; ,
With
In the path of the laser light, the optical path length difference generation unit is arranged on the irradiation surface side with respect to the split lens unit, and the light that has passed through the plurality of lenses passes through the intermediate magnification unit that constitutes the magnifying optical system. Respectively, or the split lens portion is arranged on the irradiation surface side of the optical path length difference generating portion in the path of the laser light, and has passed through the plurality of light transmitting portions. A light irradiation apparatus, wherein light is incident on each of the plurality of lenses via the intermediate zoom unit constituting the reduction optical system. The light irradiation device according to claim 1,
The light irradiating apparatus characterized in that the intermediate zooming portion constitutes a double-sided telecentric optical system. It is a light irradiation apparatus of Claim 2, Comprising:
In the path of the laser light, the optical path length difference generation unit is disposed on the irradiation surface side with respect to the split lens unit, and the intermediate zooming unit is disposed in or near the plurality of light transmitting units. A light irradiation apparatus that forms an image of an emission surface. The light irradiation device according to any one of claims 1 to 3,
The irradiation optical system further includes a reflection unit that passes through the optical path length difference generation unit and returns light emitted from a plurality of emission surfaces of the plurality of light transmission units, and causes the light to enter each of the plurality of emission surfaces. The light irradiation apparatus characterized by this. It is a light irradiation apparatus of Claim 4, Comprising:
The light irradiation apparatus, wherein the reflection unit causes light emitted from the plurality of emission surfaces to enter the plurality of emission surfaces in parallel to an emission direction of the light. A light irradiation device,
A light source unit that emits laser light toward a predetermined position;
An irradiation optical system that is disposed at the predetermined position and guides the laser light from the light source unit to the irradiation surface along the optical axis;
With
The irradiation optical system is
A plurality of lenses arranged in a direction perpendicular to the optical axis, and a split lens unit that splits incident light by the plurality of lenses;
An optical path length difference generating unit having a plurality of light transmitting parts arranged in a direction perpendicular to the optical axis, wherein the plurality of light transmitting parts have different optical path lengths;
A reflection section that transmits the light path length difference generation section and radiates light emitted from a plurality of emission faces of the plurality of light transmission sections, and makes each incident on the plurality of emission faces;
A condensing lens unit that is disposed on the irradiation surface side of the split lens unit and the optical path length difference generation unit in the laser beam path, and overlaps the irradiation regions of the light from the plurality of lenses on the irradiation surface; ,
With
In the path of the laser light, the optical path length difference generation unit is disposed on the irradiation surface side with respect to the split lens unit, and light that has passed through the plurality of lenses is incident on the plurality of light transmission units, or In the laser beam path, the split lens unit is disposed closer to the irradiation surface than the optical path length difference generating unit, and light that has passed through the plurality of light transmitting units is incident on the plurality of lenses. Light irradiation device. It is a light irradiation apparatus of Claim 6, Comprising:
The light irradiation apparatus, wherein the reflection unit causes light emitted from the plurality of emission surfaces to enter the plurality of emission surfaces in parallel to an emission direction of the light. A drawing device,
A light irradiation device according to any one of claims 1 to 7,
A spatial light modulator disposed on the irradiation surface in the light irradiation device;
A projection optical system for guiding light spatially modulated by the spatial light modulator onto an object;
A moving mechanism for moving an irradiation position on the object of the spatially modulated light;
A controller that controls the spatial light modulator in synchronization with the movement of the irradiation position by the moving mechanism;
A drawing apparatus comprising:

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