JP2012118375A - Pattern projection device and laser processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pattern projection device and a laser processing device capable of preventing deterioration of a spatial optical modulation element.SOLUTION: A laser processing device 100 according to the present invention includes: a spatial optical modulation element 45 for spatially modulating a laser beam emitted from a laser source 41 by a plurality of mirrors; an illumination optical system including an illumination system 36 for illuminating a substrate 1; an imaging lens 38 for projecting modulation light spatially modulated by the spatial optical modulation element 45 on a target object; and a deflection element 46 for deflecting the travelling direction of the laser beam output from the spatial optical modulation element 45 in a direction coinciding with an optical axis of the imaging lens 38. In the spatial optical modulation element 45, the travelling direction of laser beam incident on the spatial optical modulation element 45 is approximately parallel to a normal line of a reference surface of the spatial optical modulation element 45.

Description

  The present invention relates to a pattern projection apparatus that projects a pattern onto an object using a laser beam and a laser processing apparatus that processes an object using a laser beam.

  Conventionally, in the manufacture of various substrates such as liquid crystal displays, PDP (Plasma Display Panel), organic EL (Electro Luminescence) displays, FPD (Flat Panel Display) substrates such as surface electric electron-emitting device displays, semiconductor wafers, printed boards, etc. In order to improve the yield, after each patterning process, whether there are defects such as electrode and wiring short circuit, connection failure, disconnection, pattern failure and foreign matter such as particles and resist attached to the substrate surface by defect inspection equipment Inspected for no. And when it is confirmed by a defect inspection apparatus that a defect exists, a defect is corrected by the process using the laser beam by a laser processing apparatus.

  As this laser processing apparatus, a spatial light modulation element such as DMD (Digital Mirror Device: registered trademark) which is a micromirror array is arranged at a position conjugate with the processing surface, and a pattern formed by this DMD is irradiated with laser on the processing surface. Thus, a configuration for processing an arbitrary pattern shape on a processing surface at high speed has been proposed (see, for example, Patent Document 1 and Patent Document 2).

JP 2005-128238 A Japanese Patent Laid-Open No. 11-320963

  Here, a conventional laser processing apparatus will be described. FIG. 12 is a schematic diagram showing a schematic configuration of a conventional laser processing apparatus. FIG. 13 is a side view of a part of a conventional spatial light modulator. FIG. 14 is a side view for explaining laser light incident on a conventional spatial light modulator.

  As shown in FIG. 12, the conventional laser processing apparatus includes a laser light source 141, a spatial light modulation element 145, for example, a DMD, an imaging lens 138, and an objective lens 131, on the substrate 1 to be processed. A defect (not shown) is processed with a laser beam.

  The laser light source 141 oscillates laser light. The oscillated laser light is flattened by an optical system (not shown) and then incident on the spatial light modulator 145. This incident angle is 24.0 ° with respect to the normal of the reference plane S10 of the plurality of micromirrors 145b shown in FIG.

  The spatial light modulation element 145 is arranged so that the reference plane S10 and the processed surface of the substrate 1 are parallel to each other. The spatial light modulator 145 spatially modulates the laser light that is oscillated by the laser light source 141 and is incident on the reference surface S10, and emits the light vertically below the horizontal reference surface S10.

  The imaging lens 138 and the objective lens 131 image the modulated light emitted vertically downward from the spatial light modulator 145 on the surface of the substrate 1. Thereby, the defect on the substrate 1 is processed by the laser beam.

  As shown in FIG. 13, the spatial light modulator 145 includes a plurality of micromirrors 145b that are two-dimensionally arranged in a rectangular modulation region at an equal pitch, a support portion 145c, a rotating shaft portion 145d, and a pair. Landing pad 145e (only one is shown), a pair of address electrodes 145f, and a substrate 145g.

  The support part 145c is provided in each of the plurality of micromirrors 145b and supports the micromirrors 145b. The rotation shaft portion 145d is connected to the lower end of the support portion 145c at the center in the axial direction, and forms the rotation center of the swing motion of the micromirror 145b. The pair of landing pads 145e support both ends of the rotating shaft portion 145d spanned between them. The pair of address electrodes 145f swings the micro mirror 145b between an on state and an off state by electrostatic force. The on-state micromirror 145b emits modulated light in the direction perpendicular to the reference surface S10. The plurality of micromirrors 145b are independently swung by each pair of address electrodes 145f.

  The rotation angle of the micromirror 145b is determined at a position where the micromirror 145b stops by hitting one of the pair of landing pads 145e. The physical contact between the micromirror 145b and the landing pad 145e causes a problem called sticking. Become. Sticking is a phenomenon in which the minute mirror 145b is stuck to the landing pad 145e and cannot operate. Conventionally, a lubricant 145h is applied to the entire device of the spatial light modulator 145 in order to prevent this sticking.

  However, as shown in FIG. 14, when the micromirror 145b is in an off state inclined to the side opposite to the incident side of the laser beam L10 incident on the spatial light modulator 145, the YAG fourth harmonic ( When an ultraviolet laser beam having a wavelength of 266 nm is incident on the spatial light modulator 145 at an inclination angle of 24.0 ° with respect to the normal to the reference plane S10 of the spatial light modulator 145, in the region A10 where the ultraviolet laser light has reached, The lubricant 145h applied to the landing pad 145e is deteriorated by the ultraviolet laser light. For this reason, sticking is likely to occur in the conventional configuration.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a pattern projection device, a laser processing device, and a laser processing device capable of preventing the deterioration of the spatial light modulation element.

  In order to solve the above-described problems and achieve the object, a pattern projection apparatus according to the present invention includes a light source that emits laser light and a plurality of regularly arranged light sources in a pattern projection apparatus that projects a pattern onto an object. A spatial light modulation element that spatially modulates the laser light emitted from the laser light source corresponding to the pattern by the plurality of mirrors, an illumination optical system that illuminates the object, and the space A projection optical device that projects the modulated light spatially modulated by the light modulation element onto the object, and a direction in which the traveling direction of the laser light output from the spatial light modulation element coincides with the optical axis direction of the projection optical system The spatial light modulation element, and the spatial light modulation element has a traveling direction of laser light incident on the spatial light modulation element approximately parallel to a normal line of the reference surface of the spatial light modulation element Characterized in that there.

  According to another aspect of the present invention, there is provided a laser processing apparatus comprising: the above-described pattern projection apparatus; and a processing unit that projects the laser beam output from the pattern projection apparatus onto the target object. It is characterized by that.

  Since the traveling direction of the laser light incident on the spatial light modulation element is parallel to the normal line of the reference surface of the spatial light modulation element, the lubricant on the landing pad located on the mirror back surface of the spatial light modulation element It is possible to prevent the lubricant from being deteriorated by preventing the laser beam from being irradiated.

FIG. 1 is a block diagram illustrating a schematic configuration of a laser processing apparatus according to an embodiment. FIG. 2 is a diagram for explaining a configuration of a main part of the laser processing apparatus shown in FIG. FIG. 3 is a side view of a part of the spatial light modulation element shown in FIG. FIG. 4 is a plan view of the spatial light modulation element and the deflection element shown in FIG. FIG. 5 is a diagram for explaining the deflection element shown in FIG. 1. FIG. 6 is a diagram for explaining another configuration of the main part of the laser processing apparatus shown in FIG. FIG. 7 is a diagram for explaining another configuration of the main part of the laser processing apparatus shown in FIG. FIG. 8 is a diagram illustrating another configuration of the main part of the laser processing apparatus shown in FIG. FIG. 9 is a diagram illustrating the transparent diffractive optical element shown in FIG. FIG. 10 is a diagram for explaining another configuration of the main part of the laser processing apparatus shown in FIG. FIG. 11 is a diagram showing another configuration of the spatial light modulation element shown in FIG. FIG. 12 is a schematic diagram showing a schematic configuration of a conventional laser processing apparatus. FIG. 13 is a side view of a part of a conventional spatial light modulator. FIG. 14 is a side view for explaining laser light incident on a conventional spatial light modulator.

  Hereinafter, as an embodiment according to the present invention, for example, a laser processing apparatus that corrects pattern defects and defects by laser processing a substrate such as a glass substrate or a semiconductor wafer will be described. Note that the present invention is not limited to the embodiments. In the description of the drawings, the same parts are denoted by the same reference numerals.

(Embodiment)
Embodiments will be described. FIG. 1 is a block diagram illustrating a schematic configuration of a laser processing apparatus according to an embodiment. FIG. 2 is a diagram for explaining a configuration of a main part of the laser processing apparatus shown in FIG. In FIG. 2, a laser light source 41 is illustrated at the position of the mirror 44, and a mirror 44 and the like which will be described later are omitted from the laser processing apparatus illustrated in FIG. 1.

  As shown in FIGS. 1 and 2, a laser processing apparatus 100 according to an embodiment places a substrate 1 to be processed and moves the substrate 1 on a plane perpendicular to the drawing, and a stage 2 A microscope unit 3 for observing the substrate 1 placed on the substrate from above, and laser irradiation for shaping a beam cross-sectional shape (hereinafter referred to as a laser cross-sectional shape) of a laser beam for defect repair processing applied to the substrate 1 into a desired shape. Unit 4, control unit 5 that executes various programs and parameters to control each component of laser processing apparatus 100, and input unit 6 that receives instruction information for instructing various operations and settings to laser processing apparatus 100 The display unit 7 displays images acquired by the microscope unit 3 and various information, and the storage unit 8 stores various programs, wiring, and various sample pattern images of electrodes. The stage 2, the microscope unit 3, the laser irradiation unit 4, the input unit 6, the display unit 7, and the storage unit 8 are connected to the control unit 5 and operate under the control of the control unit 5. The laser processing apparatus 100 images a defect or the like to be processed according to the processing information, and excludes the defect extraction and the electrode pattern or the wiring pattern from the laser processing region by matching the captured defect image with a predetermined sample pattern image. In order to do this, after performing mask setting for setting a non-irradiated region of the laser beam, the defect on the substrate is processed by irradiating the laser beam. The defects include short-circuiting of electrodes and wiring, connection failure, disconnection, pattern failure, and foreign matters such as particles and resist attached to the substrate surface.

  The substrate 1 to be processed is, for example, an FPD glass substrate, a semiconductor substrate, a printed circuit board, or the like. The mounting surface of the stage 2 is provided with a plurality of holes. A gas can be supplied to these holes from a pump (not shown) to bring the substrate 1 into a floating state. In this state, the substrate 1 is held on the stage 2 by a fixing member (not shown). Alternatively, the plurality of holes can be connected to a vacuum pump (not shown), and the substrate 1 placed on the stage 2 can be sucked and fixed to the stage 2 by suction from the plurality of holes. It is. In addition to the above, mechanical means such as a support pin or a clamp mechanism may be used as the holding means for holding the substrate 1 on the stage 2 as described above. The stage 2 is freely moved in a plane orthogonal to the optical axis of the objective lens 31 described later, and changes the position of the substrate 1 on the plane with respect to the objective lens 31.

  The microscope unit 3 includes an objective lens 31, a revolver 32, a focusing mechanism 33, an imaging unit 34, an imaging unit 35, an illumination system 36, a half mirror 37a, a half mirror 37b, and an imaging lens 38 for laser light. It functions as an imaging unit that acquires an enlarged image of a part of the substrate 1.

  The objective lens 31 is held by a revolver 32 so as to be positioned above the substrate 1 placed on the stage 2. The objective lens 31 is detachably attached to the revolver 32 and is arranged on the stage 2 in accordance with the rotation or slide operation of the revolver 32. The objective lens 31 and the imaging lens 38 for laser light are arranged so as to be telecentric on both sides.

  The revolver 32 can be moved up and down by the focusing mechanism 33. The focusing mechanism 33 raises and lowers the revolver 32 to focus the objective lens 31 on the substrate 1 and optimize the focal position.

  The imaging unit 34 includes an imaging element such as a CCD sensor or a CMOS sensor. The imaging unit 35 includes an imaging lens 35a and a mirror 35b. The imaging unit 35 forms an observation image of the substrate 1 in cooperation with the objective lens 31.

  The illumination light output from the illumination system 36 is collected by the lens 36a and then reflected by the half mirror 37b, and then the substrate through the objective lens 31 as light coaxial with the observation optical axis for the substrate 1 of the observation optical system. Illuminate 1 The field of view of the imaging unit 34 is illuminated substantially uniformly from above by illumination light from the illumination system 36. The illumination system 36, the lens 36a, and the half mirror 37b function as an illumination optical system.

  An image of the illuminated substrate 1 is picked up by an observation optical system including an objective lens 31, a half mirror 37a, a mirror 35b, and an imaging lens 35a arranged along an optical axis A5 that is perpendicular to the processing surface of the substrate 1. For example, the image is magnified several times to several tens of times on the light receiving surface of the unit 34. The image data acquired by the imaging unit 34 is output to the control unit 5, subjected to various image processing, and then output to the display unit 7.

  The laser irradiation unit 4 projects a laser light source 41, an optical fiber 42 that guides the laser light emitted from the laser light source 41, and a laser light emitted from the optical fiber 42 onto a spatial light modulation element 45 described later. Projection lenses 43a and 43b, a mirror 44 that reflects the laser light from the projection lens 43b to the spatial light modulator 45, and spatial light that shapes the laser cross-sectional shape of the laser light from the laser light source 41 into a desired shape. A modulation element 45 and a deflection element 46 that deflects the laser beam output from the spatial light modulation element 45 are included. The laser irradiation unit 4 irradiates the substrate 1 with laser light spatially modulated for defect repair processing based on the image acquired by the imaging unit 34 of the microscope unit 3.

  The laser light source 41 emits laser light that is applied to the substrate 1. The laser light source 41 is configured by, for example, a YAG laser. The laser light source 41 is electrically connected to the control unit 5, and on / off of the laser beam, wavelength, light output, oscillation pulse width, and the like are controlled according to a control signal from the control unit 5. Laser light emitted from the laser light source 41 is emitted from the optical fiber 42.

  The projection lenses 43a and 43b have a function of projecting the light emitted from the optical fiber 42 onto the spatial light modulation element 45 as an image having a size with a constant projection magnification. The projection lenses 43a and 43b are arranged so as to be telecentric on both sides. The laser light emitted from the optical fiber 42 becomes a parallel light beam by the projection lens 43a, is converged by the projection lens 43b, and is collected as an image of the optical fiber 42. The mirror 44 is arranged on the optical path of the laser beam, and reflects the optical axis A1 of the laser beam in the direction of the optical axis A2 that coincides with the normal line of the reference surface of the spatial light modulator 45.

  The spatial light modulation element 45 has a configuration in which, for example, micromirrors that are one of microdevices are arranged in a two-dimensional array, and the laser light emitted from the laser light source 41 by a plurality of mirrors is made to correspond to the machining shape. Spatial modulation. The spatial light modulator 45 outputs laser light at an angle of, for example, 24.0 ° with respect to incident light. The reflection angle of each micromirror can be switched at least between an on angle and an off angle under the control of the control unit 5. The on angle is an angle at which the laser beam reflected by the micromirror in this state is projected onto the substrate 1 on the stage 2, and the off angle is the laser beam reflected by the micromirror in this state. This is an angle at which a laser damper such as a light shielding member (not shown) or an absorbing member provided outside the optical path as unnecessary light is irradiated. Therefore, it is possible to control the cross-sectional shape of the laser light projected onto the substrate 1 by switching the reflection angle of each of the micromirrors arranged in a two-dimensional array between an on angle and an off angle.

  As a result, the cross-sectional shape of the laser light from the laser light source 41 can be adjusted to the shape of the processing pattern and irradiated onto the substrate 1. This processing pattern is a processing pattern that irradiates a laser beam in addition to the normal wiring pattern. For example, when repairing a defect such as a defective pattern removal, a micromirror corresponding to a normal wiring region in the shot region Is the off angle, and the micro mirror corresponding to the other region is the on angle. For the spatial light modulation element 45, for example, a DMD may be used. The spatial light modulation element 45 adjusts the cross-sectional shape of the laser beam for defect repair output from the laser irradiation unit 4 (the shape of the cross section perpendicular to the optical axis of the laser beam) under the control of the control unit 5. The processing pattern may be set in accordance with the defect shape in addition to the normal wiring pattern as described above. In this case, the cross-sectional shape of the laser beam is matched with the defect shape, the micro mirror corresponding to the defect region is set to the on angle, and the micro mirror corresponding to the region other than the defect region is set to the off angle.

  As shown in FIG. 2, the laser light L2 is incident on the spatial light modulator 45 along the optical axis A2 that is approximately parallel to the normal line of the reference surface of the spatial light modulator 45, as shown in FIG. In other words, the spatial light modulator 45 is arranged so that the laser light L2 (optical axis A2) is incident perpendicular to the reference plane. That is, the spatial light modulation element 45 is arranged so that the traveling direction of the laser light incident on the spatial light modulation element 45 and the normal line of the reference surface of the spatial light modulation element 45 are parallel to each other.

  The deflection element 46 is, for example, a one-dimensional diffractive optical element. The deflection element 46 deflects the traveling direction of the laser light output from the spatial light modulation element 45 in a direction that coincides with the optical axis A5 of the observation optical system in the microscope unit 3. In other words, the deflecting element 46 has the optical axis A5 of the observation optical system such that the optical axis A5 of the observation optical system in the microscope unit 3 and the optical axis A3 of the laser light output from the spatial light modulation element 45 coincide. The laser beam L3 output from the spatial light modulation element 45 is deflected to the optical axis A4 that coincides with. The spatial light modulation element 45 and the deflection element 46 are arranged corresponding to the focal position of the imaging lens 38 for laser light.

  The laser light L4 irradiated from the spatial light modulation element 45 and deflected by the deflecting element 46 becomes parallel light in the imaging lens 38 for laser light, passes through the half mirror 37a and the half mirror 37b, and is off-axis from the axis. The laser beam up to is taken into the pupil plane of the objective lens 31 without leakage and projected onto the processed surface of the substrate 1. As a result, the defect that is the processing target of the substrate 1 is processed. The imaging lens 38 has a function of projecting the modulated light spatially modulated by the spatial light modulator 45 onto the processing surface of the substrate 1 that is a processing target. The deflection element 46 deflects the traveling direction of the laser light output from the spatial light modulation element 45 in a direction that coincides with the optical axis direction of the imaging lens 38. The objective lens 31 has a function of processing the defect of the substrate 1 by raising the laser light output from the imaging lens 38 to a predetermined energy density and projecting it onto the substrate 1.

  The control unit 5 includes a microscope control unit 51 and a laser processing control unit 52. The microscope control unit 51 controls the operation process of each component of the stage 2 and the microscope unit 3. The laser processing control unit 52 instructs the laser light source 41 of the laser irradiation unit 4 about the output wavelength of the laser light and controls the output of the laser light source 41.

  The input unit 6 is configured using a keyboard, a mouse, and the like, and acquires input instructions such as various setting parameters from the user in cooperation with a GUI (Graphical User Interface) displayed on the display unit 7. The display unit 7 is configured using a liquid crystal display or the like, and displays an observation image, setting information, and the like. The storage unit 8 is configured using a hard disk, a ROM, a RAM, a portable storage medium, and the like, and stores a control program and control conditions for controlling various operations of the laser processing apparatus 100 in advance. The storage unit 8 also stores a sample pattern image of an electrode (or wiring) pattern corresponding to the process / product type of the substrate 1. The laser processing apparatus 100 has a communication interface (not shown) and the like, and communicates with an external apparatus via a network.

  Next, the configuration of the spatial light modulation element 45 shown in FIGS. 1 and 2 will be described. FIG. 3 is a side view of a part of the spatial light modulator 45 shown in FIG. As shown in FIG. 3, the spatial light modulator 45 includes a micro mirror 45b, a support portion 45c, a rotation shaft portion 45d, a pair of landing pads 45e (only one is shown) as a rotation angle restricting member, and a pair of It includes an address electrode 45f and a substrate 45g.

  The support portion 45c is provided in each of the plurality of micromirrors 45b and supports the center of the back surface of the micromirror 45b. The rotation shaft portion 45d is connected to the lower end of the support portion 45c at the center in the axial direction, and becomes the rotation center of the swinging motion of the micromirror 45b.

  The pair of landing pads 45e support both ends of the rotating shaft portion 45d spanned between them, and regulate the rotation angle of the micromirror 45b by contacting the micromirror 45b.

  The pair of address electrodes 45f oscillates between an on state in which the micro mirror 45b is tilted at an on angle by an electrostatic force and an off state in which the micro mirror 45b is tilted at an off angle. The on angle and the off angle are the same angle. Therefore, the positional relationship between the on state and the off state of the micromirror 45b is symmetric with respect to one plane including the normal line of the reference surface of the spatial light modulation element 45 that passes through the rotation shaft portion 45d. The plurality of micromirrors 45b are independently swung by each pair of address electrodes 45f.

  The entire device of the spatial light modulator 45 is coated with a lubricant 45h in order to prevent sticking, which is a phenomenon in which one surface of the pair of landing pads 45e and the back surface of the micromirror 45b stick to each other and cannot operate. ing. In FIG. 3, the lubricant 45h is illustrated only on the landing pad 45e.

  The pair of landing pads 45e are arranged in the non-irradiation region A1 where the laser beam L2 (optical axis A2) is not irradiated. This non-irradiation region A1 is on the back surface side of the micromirror 45b and is on regardless of the rotation position of the micromirror 45b (even when the micromirror 45b is in the off state indicated by the solid line in FIG. 33b-1) is a region where the laser beam is not irradiated.

  As described above, the spatial light modulator 45 is disposed so that the laser light L2 (optical axis A2) is incident substantially perpendicular to the reference plane S1. Therefore, the laser beam L2 (for example, an ultraviolet laser beam such as a YAG fourth harmonic (wavelength 266 nm)) is reflected by the minute mirror 45b in both the on state and the off state, and is reflected by the minute mirror 45b. Laser light is not irradiated to the landing pad 45e of the spatial light modulator 45 located on the back surface.

  Therefore, in the embodiment, it is possible to reduce the irradiation of the laser beam to the lubricant 45h applied to the landing pad 45e without separately providing a member for preventing the deterioration of the lubricant. As a result, according to the embodiment, it is possible to prevent the lubricant 45h applied to the landing pad 45e from being deteriorated, and to reduce the occurrence of sticking.

  Next, the deflection element 46 shown in FIGS. 1 and 2 will be described. FIG. 4 is a plan view of the spatial light modulation element 45 and the deflection element 46 shown in FIG. As shown in FIG. 4, the laser light L <b> 2 is incident on the spatial light modulator 45 at a point P <b> 1 with an optical axis that matches the normal line of the reference surface of the spatial light modulator 45. When the minute mirror 45b located at the point P1 in the spatial light modulation element 45 is in the ON state, the incident laser light is 45 ° when the spatial light modulation element 45 is viewed from above (the front side in FIG. 4). The laser beam L3 is emitted in the direction.

  As shown in FIG. 4, in the deflection element 46, grooves perpendicular to the 45 ° direction are arranged on the surface on the spatial light modulation element 45 side. As shown in FIG. 5, the deflection element 46 is a one-dimensional diffractive optical element, and grooves are formed at the same pitch as the mirror pitch of the spatial light modulation element 45. Further, the groove of the deflection element 46 has an inclined surface that is inclined at the same angle as the ON angle of the micro mirror 45 b of the spatial light modulator 45. For example, the wavelength of the laser beam used is 266 nm. The spatial light modulator 45 has a pixel surface tilt angle (on angle, off angle) of the micromirror 45b of 12.0 ° and a mirror pitch of 11.1 μm. In this case, the groove pitch of the deflection element 46 is 11.1 μm which is the same as the mirror pitch, and the inclination angle of the inclined surface is set to 12.0 ° which is the same as the pixel surface inclination angle.

  In the embodiment, a deflection element 46 is disposed between the spatial light modulation element 45 that outputs laser light at a predetermined angle with respect to incident light and the imaging lens 11, and is output from the spatial light modulation element 45. The laser beam L3 is corrected to a laser beam L4 having an optical axis A4 coaxial with the optical axis A5 of the observation optical system. Thus, in the embodiment, since the laser beam L3 output from the spatial light modulator 45 is corrected coaxially with the optical axis A5 of the observation optical system, the optical axis A5 of the observation optical system is aligned with that of the substrate 1. It can be set perpendicular to the processing surface, and the laser irradiation unit 4 can be easily incorporated into the observation optical system of the microscope unit 3. In the present embodiment, since the reference surface S1 of the spatial light modulator 45 and the processed surface of the substrate 1 can be arranged in parallel, assembly of each optical system other than the optical system of the observation optical system is also possible. It becomes easy.

  In the embodiment, as shown in FIG. 5, the traveling direction of the laser light deflected by the deflecting element 46 is tilted by 0.037 ° with respect to the optical axis A5 in the microscope section 3, and the deflecting element 46 has the strongest intensity. The position may be strictly adjusted so that the laser beam can be diffracted by.

  In the embodiment, as shown in FIG. 6, a deflection element 46a which is a two-dimensional diffractive optical element may be used. Also in this case, the deflecting element 46a has a grating formed at the same pitch as the mirror pitch of the spatial light modulator 45, and each grating surface has the same angle as the ON angle of the micro mirror 45b of the spatial light modulator 45. Incline at. For example, the wavelength of the laser beam used is 266 nm, the pixel surface tilt angle (on angle, off angle) of the micro mirror 45 b of the spatial light modulator 45 is 12.0 °, and the mirror pitch is 11.1 μm. In this case, the grating pitch of the deflecting element 46a is 11.1 μm which is the same as the mirror pitch, and the inclination angle of the grating surface is set to 12.0 ° which is the same as the pixel surface inclination angle.

  In the embodiment, as shown in FIG. 7, a micro mirror array 46b having the same configuration as the spatial light modulation element 45 may be used. In this case, the laser light L3 output from the spatial light modulation element 45 can be corrected to a laser light coaxial with the optical axis A5 of the observation optical system by turning on all the minute mirrors.

  In the embodiment, as shown in FIG. 8, a transparent diffractive optical element 46 c formed of a transparent material may be used instead of the deflection element 46. In FIG. 8, the projection lenses 43a and 43b shown in FIG. 1 are not shown.

  As shown in FIG. 8, the transparent diffractive optical element 46c and the spatial light modulating element 45 are arranged so that the laser light L3 output from the spatial light modulating element 45 is perpendicularly incident on the back surface of the transparent diffractive optical element 46c. It is arranged between the imaging lens 38. At this time, the back surface of the transparent diffractive optical element 46c is at an angle β with respect to the plane orthogonal to the optical axis A3, corresponding to the spatial light modulator 45 outputting laser light at an angle β with respect to the incident light. It is arranged to be inclined. This angle β is, for example, 24.02 °.

  As shown in FIG. 9, the transparent diffractive optical element 46c has a structure in which a plurality of grooves are formed at a predetermined pitch on the surface, and the laser beam L3 incident from the back surface coincides with the direction of the optical axis A5 on the surface. Are deflected in the direction to be output and output as laser light L4.

The blaze angle θ _B which is the inclination angle of the groove on the surface of the transparent diffractive optical element 46 is the refractive index n of the constituent material of the transparent diffractive optical element 46c, the diffraction order m, the number of grooves N per mm, the wavelength of incident light Using λ, it is expressed as the following equation (1).

For example, when using a transparent diffractive optical element 46c having a refractive index of 1.5, a diffraction order of 15, and 102 grooves per mm, when using 266 nm ultraviolet laser light for processing The blaze angle θ _B of the transparent diffractive optical element 46c may be set to 34.75 °.

  In addition, when the diffraction efficiency varies from the set value due to a manufacturing error of the spatial light modulator 45, the laser light incident condition to the spatial light modulator 45 may also vary. Therefore, in the embodiment, as shown in FIG. 10, the incident angle adjusting mechanism 47 that adjusts the incident angle of the laser light incident on the spatial light modulator 45 and the spatial light modulator 45 are inclined to the deflection element 46. An angle adjustment mechanism 48 that adjusts the inclination angle of the spatial light modulator 45 may be further provided. In this case, the laser processing control unit 252 in the control unit 250 controls the incident angle adjusting mechanism 47 and the angle adjusting mechanism 48 so that the laser light incident on the spatial light modulator 45 is incident so that the diffraction efficiency satisfies the set value. Adjust the angle.

  For example, the case where the mirror pitch of the spatial light modulator 45 is 11.1 μm and the ON angle of the minute mirror 45b is 11.9 ° instead of the set value of 12.0 ° will be described as an example. In this case, the incident angle adjusting mechanism 47 sets the incident angle of the laser light incident on the spatial light modulator 45 to be inclined by 3.0 ° with respect to the normal to the reference plane of the spatial light modulator 45, and adjusts the angle. The mechanism 48 sets the inclination angle of the spatial light modulation element 45 with respect to the deflection element 46 to 3.2 °. In this case, the groove pitch of the deflecting element 46 which is a one-dimensional diffractive optical element is 11.1 μm which is the same as the mirror pitch, and the inclination angle of the inclined surface is 12.0 ° which is the same as the set value of the pixel surface inclination angle. You can leave it. Also in the configuration of FIG. 10, it is of course possible to use a deflection element 46a which is a two-dimensional diffractive optical element as the deflection element. In this case, the grating pitch of the deflection element 46a is the same as the mirror pitch. .1 μm, and the inclination angle of the lattice plane may remain 12.0 °, which is the same as the set value of the pixel plane inclination angle. Of course, the micromirror array 46b can also be used as the deflecting element in the configuration of FIG.

  In the embodiment, a spatial light modulation element 345 shown in FIG. 11 may be used instead of the spatial light modulation element 45. In the spatial light modulator 345, an antireflection material 345i is formed in a region between the micromirrors 45b on which the laser light L2 is incident in either the on state or the off state on the substrate 45g. The antireflection material 345i can suppress the reflection of the laser light L2 that has reached the substrate 45g to the back surface side of the micromirror 45b. Therefore, since the laser beam L2 does not rebound from the substrate 45g with respect to the lubricant 45h, the deterioration of the lubricant 45h can be further prevented, and the occurrence of sticking can be reduced. It is also effective to provide a structure for trapping laser light such as providing a groove instead of the antireflection material.

  In this embodiment, a laser processing apparatus that corrects defects on the processed surface of the substrate 1 using laser light has been described as an example. However, the present invention is not limited to this, and laser light emitted from a laser light source is used. The present invention can also be applied to a pattern projection apparatus such as an exposure apparatus that projects a pattern onto an object by spatial modulation.

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Stage 3 Microscope part 4 Laser irradiation part 5 Control part 6 Input part 7 Display part 8 Memory | storage part 31 Objective lens 32 Revolver 33 Focusing mechanism 34 Imaging part 35 Imaging part 35a Imaging lens 35b, 44 Mirror 36 Illumination system 36a Lens 37a, 37b Half mirror 38 Imaging lens 41 Laser light source 42 Optical fiber 43a, 43b Projection lens 45 Spatial light modulation element 45b Micro mirror 45c Support part 45d Rotating shaft part 45e Landing pad 45f Address electrode 45g Substrate 45h Lubricant 46, 46a Deflection element 46b Micro mirror array 47 Incident angle adjustment mechanism 48 Angle adjustment mechanism 51 Microscope control unit 52 Laser processing control unit 100 Laser processing apparatus

Claims (5)

In a pattern projection apparatus that projects a pattern onto an object,
A light source that emits laser light;
A spatial light modulation element that has a plurality of regularly arranged mirrors and spatially modulates the laser light emitted from the laser light source in correspondence with the pattern by the plurality of mirrors;
An illumination optical system for illuminating the object;
A projection optical device that projects the modulated light spatially modulated by the spatial light modulation element onto the object;
A deflection element that deflects the traveling direction of the laser light output from the spatial light modulation element in a direction that coincides with the optical axis direction of the projection optical system;
With
The pattern projection apparatus, wherein the spatial light modulation element has a traveling direction of laser light incident on the spatial light modulation element substantially parallel to a normal line of a reference plane of the spatial light modulation element. The air conditioning light modulation element can switch between an on state in which the reflection angle of the mirror is inclined at an on angle and an off state in which the reflection angle is inclined at an off angle,
The pattern projection according to claim 1, wherein a positional relationship between the on state and the off state is symmetric with respect to one plane including the normal passing through the rotation axis of the mirror. apparatus.   2. The deflection element according to claim 1, wherein the deflection element is a one-dimensional diffractive optical element, a two-dimensional diffractive optical element, a diffractive optical element having a plurality of mirrors arranged in two dimensions, or a transparent diffractive optical element. Pattern projection device.   The spatial light modulation element further includes a substrate on which the plurality of mirrors are arranged, and an antireflection material that prevents reflection of the laser light formed in a region on the surface of the substrate where the laser light is incident. The pattern projection apparatus according to claim 1, further comprising: In a laser processing apparatus that processes an object using laser light,
The pattern projection device according to any one of claims 1 to 4,
A processing unit for processing the object by projecting the laser beam output from the pattern projection optical device onto the object;
A laser processing apparatus comprising:

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