JP2014048649A - Exposure drawing apparatus and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure drawing apparatus and program in which exposure amount can be adjusted, and fluctuation of light volume when ejecting light of low light volume can be made small.SOLUTION: An exposure head 16a includes: a laser source 30; a light volume control part 50 that has a reflection surface that reflects light from the laser source 30 and in which reflectance is adjustable, and that ejects reflection light having a light volume corresponding to reflectance in the reflection surface; first optical systems 31, 32 that adjust illuminance distribution of reflection light from the light volume control part 50, and form adjustment light; DMD27 that performs spatial modulation of adjustment light, and generates pattern light corresponding to a drawing pattern; and second optical systems 34, 35 that irradiate the pattern light to a surface to be exposed. The light volume control part 50 has a first reflection surface and a second reflection surface having different reflectances, and one of the first and second surfaces is arranged on a light path depending on a control signal.

Description

  The present invention relates to an exposure drawing apparatus and a program, and more particularly to an exposure drawing apparatus for drawing an image on a substrate and a program executed by the exposure drawing apparatus.

  In recent years, when performing exposure drawing of a drawing pattern on a substrate to be exposed, a spatial light modulation element such as a digital micromirror device (hereinafter referred to as DMD) is used as a pattern generator, and the above drawing is performed by this spatial light modulation element. Development of an exposure drawing apparatus that performs exposure drawing on a substrate to be exposed with a light beam modulated in accordance with image data indicating a pattern is underway.

  The DMD is, for example, a mirror device in which a number of micromirrors whose reflection surfaces change in response to a control signal are two-dimensionally arranged on a memory cell matrix, and are microscopically generated by electrostatic force generated by charges stored in each memory cell. The angle of the reflecting surface of the mirror is changed. In an exposure drawing apparatus having a DMD, each of the micromirrors of the DMD is controlled to be turned on / off based on image data or the like to modulate a light beam for each pixel, and the modulated light beam is exposed to the substrate to be exposed.

  In such an exposure drawing apparatus, the lens used in the optical system in the exposure head has a unique distortion characteristic called distortion (distortion aberration). For this reason, the designed drawing pattern (hereinafter also referred to as “design drawing pattern”) and the drawing pattern actually exposed and drawn on the exposed surface do not have a similar relationship. That is, the design drawing pattern is drawn on the exposed surface in a state of being deformed by distortion. This deformation of the drawing pattern becomes a problem when a fine pattern such as a circuit pattern requiring high accuracy is drawn by exposure.

  In order to deal with such a problem, in Patent Document 1, the irradiation position of the light beam that is actually irradiated onto the surface to be exposed is detected for each pixel using a photosensor, and the exposure is performed from the detected light beam irradiation position. There has been proposed an exposure drawing apparatus that derives a distortion amount of an actual drawing pattern drawn on a surface with respect to a design drawing pattern and corrects the design drawing pattern based on the derived distortion amount.

  Patent Document 2 describes that the amount of light emitted from the exposure head is adjusted by providing a transmission type attenuator between the illumination optical system and the light modulator in the exposure head. .

JP 2005-316409 A JP 2010-26465 A

  By the way, when an ultra-sensitive material such as a silver salt sensitive material is to be exposed, it is necessary to perform exposure with a light amount sufficiently smaller than that when a normal-sensitive material is to be exposed. On the other hand, in an exposure drawing apparatus having a function of correcting the irradiation position of light emitted from the exposure head as disclosed in Patent Document 1, it is sufficient to detect the actual irradiation position using a photosensor. Light intensity is required. If the amount of light is insufficient, the S / N of the detection signal from the photo sensor is lowered, and the detection accuracy of the actual irradiation position of the light beam is lowered. Therefore, when an ultrasensitive material is used as an exposure target, it is necessary to detect the irradiation position with a light amount different from the light amount of the light beam at the time of exposure drawing.

  Therefore, as described in Patent Document 2, it is conceivable to provide an attenuator in the optical path to adjust the amount of light. However, when using a transmission type attenuator as described in Patent Document 2 to significantly attenuate incident light, the individual variation of the attenuators becomes a problem. For example, when a transmission type attenuator is used to obtain transmitted light having a light amount of about 4% of the incident light amount, if the individual variation of the transmittance of the attenuator is ± 1%, the transmitted light amount is ± 25%. It will vary. As described above, it is difficult for the transmission type attenuator to suppress variations in the light amount when the attenuation factor is increased to obtain a low amount of transmitted light. If the amount of transmitted light varies greatly, it may be impossible to expose the ultrasensitive material with an appropriate amount of light.

  The present invention has been made in view of the above problems, and provides an exposure drawing apparatus and program capable of adjusting the exposure amount in a wide range and reducing the variation in the amount of light when emitting a low amount of light. The purpose is to do.

  In order to achieve the above object, an exposure drawing apparatus according to the present invention has a light source and a reflective surface having a variable reflectivity for reflecting light from the light source, and has an amount of light corresponding to the reflectivity on the reflective surface. A light amount adjustment unit that emits reflected light, a first optical system that introduces the reflected light, adjusts an illuminance distribution of the reflected light, and generates adjustment light, and spatially modulates the adjustment light into a drawing pattern A light modulation unit that generates corresponding pattern light, and a second optical system that forms an image of the pattern light on an exposed surface.

  The light amount adjustment unit may include a plurality of reflection surfaces having different reflectances and a drive unit that arranges any of the plurality of reflection surfaces on the optical path in accordance with a control signal.

  In this case, the light amount adjusting unit includes a first reflective surface configured by the surface of the light reflective member and a second reflectance lower than the first reflective surface configured by the surface of the light transmissive member. And a reflective surface.

  Further, the second reflecting surface may be constituted by a glass surface. In this case, the 1st reflective surface may be comprised by the light reflection film which coat | covers the surface of the base material which consists of glass, and the 2nd reflective surface may be comprised by the non-coat surface of the base material.

  Further, the light amount adjustment unit may include a reflection surface constituted by the surface of the light transmissive member, and a drive unit that changes an incident angle of light from the light source with respect to the reflection surface according to a control signal, The reflectance on the reflection surface may be configured to change according to the incident angle of light from the light source.

  In addition, the exposure drawing apparatus according to the present invention includes an acquisition unit that acquires information on the light sensitivity of the surface to be exposed, and a first control unit that controls the reflectance on the reflection surface according to the information acquired by the acquisition unit. , May be further included.

  The exposure drawing apparatus according to the present invention may further include second control means for controlling the intensity of light generated in the light source in accordance with information acquired by the acquisition means.

  The exposure drawing apparatus according to the present invention further includes third control means for controlling the moving speed of the stage on which the exposure object having the exposed surface is placed according to the information acquired by the acquisition means. Also good.

  The exposure drawing apparatus according to the present invention is detected by a detection surface provided in the same plane as the surface to be exposed, an irradiation position detection unit that detects an irradiation position on the detection surface of the pattern light, and an irradiation position detection unit. Correction means for correcting the irradiation position of the pattern light based on the irradiation position of the patterned light may be further included.

  The first optical system may include a rod integrator.

  In addition, the exposure drawing apparatus according to the present invention may further include a condenser lens disposed between the light amount adjusting unit and the rod integrator. In this case, the reflecting surface of the light amount adjusting unit and the light incident surface of the rod integrator can be disposed at a conjugate position with respect to the condenser lens.

  In addition, the exposure drawing apparatus according to the present invention may further include a temperature adjusting unit that maintains the temperature of the light modulation unit within a predetermined range.

  The light source may include a laser that emits laser light.

  The exposure drawing apparatus according to the present invention may further include a light guide that generates random polarized light from the laser light and guides it to the reflecting surface.

  The exposure drawing apparatus according to the present invention may further include a light absorbing member that absorbs light transmitted through the reflecting surface.

  In order to achieve the above object, the program of the present invention controls the reflectance on the reflection surface according to the information acquired by the computer, the acquisition means for acquiring the information related to the photosensitivity of the exposed surface. Exposure having a surface to be exposed according to information acquired by the first control means, second control means for controlling the intensity of light generated in the light source according to the information acquired by the acquisition means, and information acquired by the acquisition means It is configured to function as a third control unit that controls the moving speed of the stage on which the object is placed, and controls the exposure drawing apparatus according to the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the exposure drawing apparatus and program which can adjust exposure amount to a wide range and can reduce the light quantity dispersion | variation at the time of radiate | emitting a low light quantity light can be provided.

It is a perspective view which shows the structure of the exposure drawing apparatus which concerns on embodiment of this invention. It is a schematic perspective view of the principal part which shows the state at the time of exposure drawing in the exposure drawing apparatus which concerns on embodiment of this invention. It is a schematic perspective view of the principal part which shows the state at the time of exposure drawing in the exposure drawing apparatus which concerns on embodiment of this invention. It is sectional drawing along the optical path which shows the structure of the exposure head which concerns on embodiment of this invention. It is a top view which shows the structure of the light quantity adjustment part which concerns on embodiment of this invention. It is a perspective view which shows the structure of DMD which concerns on embodiment of this invention. It is a block diagram which shows the electric system of the exposure drawing apparatus which concerns on embodiment of this invention. It is a flowchart which shows the flow of a process of the exposure control processing program which concerns on embodiment of this invention. It is a flowchart which shows the flow of a process of the irradiation position correction process program which concerns on embodiment of this invention. (A) is a figure for demonstrating the method to detect the irradiation position of a to-be-measured pixel in the exposure drawing apparatus which concerns on embodiment of this invention, (B) is the exposure drawing apparatus which concerns on embodiment of this invention. FIG. 2 is an explanatory diagram showing the detection signal of the photosensor corresponding to (A). It is the schematic which shows an example of distortion correction of exposure drawing in the exposure drawing apparatus which concerns on embodiment. It is sectional drawing along the optical path which shows the structure of the light quantity adjustment part which concerns on the 2nd Embodiment of this invention. It is a graph which shows the relationship between the incident angle of light and the reflectance in the light quantity adjustment part which concerns on the 2nd Embodiment of this invention.

[First Embodiment]
Hereinafter, an exposure drawing apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same or equivalent components and parts are denoted by the same reference numerals. In the present embodiment, the exposed substrate C is exposed using a film having a photosensitive material such as a resist film on the surface, a flat substrate such as a printed wiring board and a glass substrate for a flat panel display as the exposed substrate C. An exposure drawing apparatus that performs drawing will be described as an example.

  FIG. 1 is a perspective view showing a configuration of an exposure drawing apparatus 1 according to an embodiment of the present invention. In the following, the direction in which the stage 10 moves is defined as the Y direction, the direction perpendicular to the Y direction on the horizontal plane is defined as the X direction, and the direction perpendicular to the Y direction on the vertical plane is defined as the Z direction. The direction of rotation about the Z axis is defined as the θ direction.

  As shown in FIG. 1, the exposure drawing apparatus 1 includes a flat plate stage 10 for fixing a substrate C to be exposed. On the upper surface of the stage 10, a suction mechanism (not shown) having a plurality of suction holes for sucking air is provided in a region where the substrate C to be exposed is placed. The suction mechanism is configured to suck the air between the surface to be exposed C and the stage 10 from the suction hole when the substrate to be exposed C is fixed to the upper surface of the stage 10. The substrate to be exposed C is sucked and held on the stage 10 by vacuum suction.

  Further, the stage 10 is configured to be movable, and the exposure substrate C fixed to the stage 10 moves to the exposure position as the stage 10 moves, and the exposure unit 16 is irradiated with the light beam to be exposed. An image such as a circuit pattern is drawn on the surface.

  The stage 10 is supported by a flat base 12 that is movably provided on the upper surface of a table-like base 11. Further, a moving mechanism unit (not shown) having a moving drive mechanism configured by a motor or the like is provided between the base 12 and the stage 10, and the stage 10 has a thickness of the stage 10 by the moving mechanism unit. It can be translated in the vertical direction (Z direction).

  One or a plurality of (in this embodiment, two) guide rails 14 are provided on the upper surface of the base 11. The base 12 is supported so as to be movable on the guard rail 14 and is moved by a stage driving unit (stage driving unit 46 described later) constituted by a motor or the like. The stage 10 is moved along the guide rail 14 by being supported on the upper surface of the movable base 12.

  A gate-type gate 15 is erected on the upper surface of the base 11 so as to straddle the guide rail 14, and an exposure unit 16 is attached to the gate 15. The exposure unit 16 has a plurality of exposure heads 16 a and is fixedly arranged on the moving path of the stage 10. In the present embodiment, the exposure unit 16 has 16 exposure heads 16a arranged in a matrix of 2 rows and 8 columns. An optical fiber 18 drawn from the light source unit 17 and a signal cable 20 drawn from the image processing unit 19 are connected to the exposure unit 16.

  A gate-shaped gate 22 is provided on the upper surface of the base 11 so as to straddle the guide rail 14. One or a plurality of (two in the present embodiment) imaging units 23 for imaging the alignment mark of the substrate C to be exposed placed on the stage 10 are attached to the gate 22. The photographing unit 23 is a CCD camera or the like having a built-in strobe with a very short light emission time. Each of the imaging units 23 is installed so as to be movable in a direction (X direction) perpendicular to the moving direction (Y direction) of the stage 10. When the exposure drawing apparatus 1 draws a drawing pattern on the exposed substrate C, the exposure drawing apparatus 1 measures the position of the alignment mark photographed by the photographing unit 23 and adjusts the drawing position based on the measured position of the alignment mark.

  FIG. 2 is a schematic perspective view of a main part showing a state during exposure drawing in the exposure drawing apparatus 1 according to the present embodiment. In FIG. 2, only a part of the exposure head 16 a provided in the exposure unit 16 is shown for easy understanding.

  For example, the exposure area R1 by the exposure head 16a is formed in a rectangular shape having a short side in the scanning direction of the exposure head 16a (the Y direction that is the moving direction of the stage 10). On the substrate C to be exposed, a strip-shaped exposed area R2 is formed for each exposure head 16a as the stage 10 moves in the Y direction.

  Further, as shown in FIG. 2, each of the exposure heads 16a arranged in the X direction is arranged so that the position in the X direction is shifted from each of the adjacent exposure heads 16a in the Y direction. Thereby, for example, an area that cannot be exposed by the exposure heads 16a adjacent to each other in the X direction is exposed by the exposure head 16a adjacent in the Y direction.

  FIG. 3 is a perspective view of a main part showing a state during exposure drawing in the exposure drawing apparatus 1 according to the present embodiment. As shown in FIG. 3, a slit plate 24 is provided at the end of the stage 10. The slit plate 24 is provided such that its upper surface extends in the same plane as the upper surface of the stage 10. The slit plate 24 is made of a rectangular long plate-like quartz glass plate having a length equal to the width of the stage 10 (length in the X direction) and a thin chromium film (chrome mask, emulsion mask) covering the quartz glass plate. And a plurality of detection slits 25 formed by partially removing the light shielding film. The detection slit 25 transmits the light beam emitted from the exposure head 16a to the lower surface side of the slit plate 24 (surface opposite to the side on which the substrate to be exposed C is placed).

  The detection slit 25 has a saddle shape that is orthogonal so that two line segments open in the X-axis direction. For the detection slit 25, for example, after a resist mask is formed on the light shielding film, the resist mask is subjected to patterning corresponding to the pattern of the detection slit 25, and the light shielding film exposed at the opening of the resist mask is removed by etching. It is formed by doing. In addition, the deformation | transformation by a temperature change can be made small by using quartz glass as a base material of the slit board 24. FIG. Further, by using a thin chrome film as the light shielding film, the exposure position of the light beam can be detected with high accuracy.

  A plurality of photosensors 26 corresponding to each of the inspection slits 25 are provided on the lower surface of the slit plate 24. The light beam emitted from the exposure head 16 a and passing through the inspection slit 25 is irradiated to the photo sensor 26. The photo sensor 26 outputs a detection signal when it detects the light beam that has passed through the inspection slit 25. The irradiation position of the light beam emitted from the exposure head 16a can be detected by a detection signal of the photosensor 26.

  The exposure drawing apparatus 1 according to the present embodiment detects the irradiation position of the light beam irradiated to the exposed surface of the substrate C to be exposed for each pixel using the photo sensor 26, and from the detected irradiation position of the light beam. An irradiation position correction function that corrects the irradiation position of the light beam by deriving the amount of distortion of the actual drawing pattern drawn on the exposed surface from the design drawing pattern and correcting the design drawing pattern based on the derived amount of distortion have.

  Each exposure head 16a has a digital micromirror device (DMD) 27, which will be described later, as a reflective spatial light modulation element, and controls the DMD 27 based on image data input from the image processing unit 19 to control the light source unit 17. Is subjected to spatial modulation, and the substrate C is irradiated with the spatially modulated light beam. Thereby, exposure drawing of an image according to the image data is performed on the substrate C to be exposed.

  FIG. 4 is a cross-sectional view along the optical path showing the configuration of the exposure head 16a. In FIG. 4, the components of the control system of the stage 10, the light source unit 17, and the exposure drawing apparatus 1 are shown together with the exposure head 16a.

  The light source unit 17 includes a laser light source 30 and a laser driving unit 41. The laser drive unit 41 generates a drive current having a magnitude corresponding to the control signal supplied from the system control unit 40 and supplies this to the laser light source 30. The laser light source 30 is configured by, for example, a semiconductor laser, and emits a laser beam having a light amount (intensity) corresponding to the drive current supplied from the laser drive unit 41. Laser light emitted from the laser light source 30 is led out of the light source unit 17 by the optical fiber 18. The laser light emitted from the laser light source 30 is repeatedly reflected in the optical fiber 18 serving as a light guide, and is emitted as random polarized light from the emission end of the optical fiber 18. Laser light emitted from the optical fiber 18 is introduced into the exposure head 16a and irradiated onto a light reflecting surface of a light amount adjusting unit 50 described later. In addition, the dispersion | variation in the reflectance in the reflective surface of the light quantity adjustment part 50 mentioned later can be suppressed by making a laser beam into random polarization | polarized-light with the optical fiber 18. FIG.

  The exposure head 16a includes a light amount adjusting unit 50, a condenser lens 70, a rod integrator 31, a first lens system 32, a reflecting mirror 33, a DMD 27, a second lens system 34, and a focusing mechanism 35.

  The light amount adjusting unit 50 has two reflecting surfaces (a first reflecting surface 52 and a second reflecting surface 53 shown in FIG. 5) having different reflectances, and is emitted from the emitting end portion of the optical fiber 18. The beam is reflected on one of the reflecting surfaces, and a light beam (reflected light) having a light amount corresponding to the reflectance on the reflecting surface is emitted. The light amount adjusting unit 50 selectively arranges one of the two reflecting surfaces in the optical path to change the light amount of the light beam emitted from the exposure head 16a. The light amount adjusting unit 50 is disposed such that the direction of the reflecting surface is inclined with respect to the incident direction of the laser light so that the reflected light is emitted in a direction different from the incident direction of the light beam supplied from the optical fiber 18. Has been.

  FIG. 5 is a plan view seen from the reflection surface side of the light amount adjustment unit 50 according to the present embodiment. The light amount adjusting unit 50 includes a rectangular base material 51 made of a light transmissive member such as glass. On the main surface of the base material 51, a first reflection surface 52 and a second reflection surface 53 having different reflectivities are provided in parallel.

  The first reflecting surface 52 is formed by covering the main surface of the base material 51 with a high reflectivity member 54 made of aluminum, Ag, or the like. As a result, the first reflecting surface 52 has a relatively high reflectivity (for example, 95% or more), and the light beam reflected by the first reflecting surface 52 is hardly attenuated and is a rod integrator. 31. A dielectric multilayer film may be used as the high reflectivity member 54. The dielectric multilayer film is formed by alternately laminating a dielectric film having a thickness corresponding to a quarter wavelength of incident light and having a relatively high refractive index and a dielectric film having a relatively low refractive index. By using such a dielectric multilayer film for the high reflectance member 54, a higher reflectance can be obtained at the first reflecting surface 52.

The second reflecting surface 53 is configured as a non-coated surface in which the main surface of the substrate 51 is not coated. Thereby, the second reflecting surface 53 has a lower reflectance than the first reflecting surface 52. In this embodiment, quartz glass having a refractive index of about 1.5 is used as the substrate 51, and about 4% of incident light incident on the second reflecting surface 53 is introduced into the rod integrator 31 as reflected light. The remaining 96% passes through the substrate 51. Thus, by configuring the second reflective surface 53 with the non-coated surface (that is, the glass surface) of the base material 51, the reflectance (relative intensity of the reflected light with respect to the incident light) on the second reflective surface is as follows. As shown in the equations (1) and (2), it depends only on the refractive index of the substrate 51, the incident angle of light, and the polarization state of incident light. As a result, when the incident light is greatly attenuated and an extremely low amount of light is extracted, the variation in the amount of light can be significantly reduced as compared with the transmission type attenuator. For example, when the second reflecting surface 53 is irradiated with randomly polarized light, the intensity variation of the reflected light can be suppressed to about ± 5%. In the following formulas (1) and (2), rs is a reflectance with respect to the s-polarized component, rp is a reflectance with respect to the p-polarized component, θ _i is an incident angle of light with respect to the second reflecting surface 53, and θ _t Is the refraction angle of light transmitted through the substrate 51.

rs = {sin (θ _i −θ _t ) / sin (θ _i + θ _t )} ² (1)
rp = {tan (θ _i −θ _t ) / tan (θ _i + θ _t )} ² (2)
The light absorbing unit 80 shown in FIG. 4 is made of, for example, a metal surface-treated in black, and absorbs the light beam transmitted through the second reflecting surface 53 and converts it into heat. Thereby, it is possible to prevent the light beam transmitted through the second reflecting surface 53 from becoming stray light. In addition, it is preferable to arrange | position in the position where the heat which the light absorption part 80 emits does not affect an exposure system.

  Further, the light amount adjusting unit 50 is provided with a reflecting surface driving unit 60. The reflecting surface driving unit 60 moves the base 51 in the direction indicated by the arrow in FIG. 5 according to the control signal supplied from the system control signal 40 (the direction in which the first reflecting surface 52 and the second reflecting surface 53 are arranged). By moving the first reflective surface 52 or the second reflective surface 53, one of the first reflective surface 52 and the second reflective surface 53 is arranged on the optical path. That is, the light beam emitted from the optical fiber 18 is reflected by one of the first reflecting surface 52 and the second reflecting surface 53 and is introduced into the rod integrator 31 at the subsequent stage.

  The condensing lens 70 is a lens for condensing the light beam reflected on the first reflecting surface 52 or the second reflecting surface 53 of the light amount adjusting unit 50 on the rod integrator 31. The first reflective surface 52 or the second reflective surface 53 of the light amount adjusting unit 50 disposed on the optical path and the light incident surface of the rod integrator 31 are in a conjugate positional relationship with the condenser lens 70. Has been placed. Thereby, even if the incident angle of the light beam with respect to the first reflecting surface 52 and the second reflecting surface 53 slightly varies, the reflected light can be introduced into the rod integrator 31.

  The rod integrator 31 is a translucent rod formed in, for example, a quadrangular prism shape. The light beam incident on the rod integrator 31 travels while totally reflecting the inside of the translucent rod. Thereby, the illuminance distribution in the light beam cross section is made uniform. A fly-eye lens may be used instead of the rod integrator as an optical member for obtaining a uniform illuminance distribution. The light beam whose illuminance distribution is made uniform by the rod integrator 31 is incident on the first lens system 32.

  The first lens system 32 includes a combination lens 32a including a pair of lenses for collimating an incident light beam, and a pair of lenses for correcting the light quantity distribution of the collimated light beam to be uniform. And a condensing lens 32c that condenses the light beam with the corrected light quantity distribution on the reflecting mirror 33. In the combination lens 32b, with respect to the arrangement direction of the laser emitting ends, the portion close to the optical axis of the lens expands the light beam, and the portion away from the optical axis contracts the light beam, and in a direction orthogonal to the arrangement direction. On the other hand, it has a function of allowing light to pass through as it is, and corrects the laser light so that the light quantity distribution is uniform.

  The light beam emitted from the first lens system 32 is reflected by the reflecting mirror 33 and applied to the DMD 27.

  FIG. 6 is a perspective view showing the configuration of the DMD 27 according to the present embodiment. As shown in FIG. 6, the DMD 27 is configured as a mirror device in which a large number of (for example, 600 × 800) micromirrors (micromirrors) 29 constituting a pixel (pixel) are arranged in a lattice pattern. . Each of the rectangular micromirrors 29 is supported by a pillar including a hinge and a yoke (not shown) on an SRAM cell (memory cell) 28 made of silicon gate CMOS or the like for temporarily storing image data indicating a drawing pattern. Has been. A material having high reflectivity such as aluminum is deposited on the surface of the micromirror 29 to form a light reflecting surface. Each pixel of the drawing pattern is constituted by the light beam reflected by each of the micromirrors 29.

  In the SRAM cell 28 of the DMD 27, a digital signal indicating the on state or the off state of each micromirror 29 generated based on the image data of the drawing pattern is written. The micromirror 29 in the on state has its reflecting surface inclined with the diagonal line as the rotation axis until one corner of the micromirror 29 comes into contact with the landing pad on the SRAM cell. On the other hand, the reflective surface of the micromirror 29 in the off state is inclined with the diagonal line as the rotation axis until the corner facing the one corner contacts the other landing pad.

  In this way, by controlling the inclination of each micromirror 29 so as to correspond to each pixel in the image data of the drawing pattern, the light beam incident on the DMD 27 is reflected in a direction according to the inclination of the micromirror 29. Exposure drawing of a drawing pattern is performed.

  The on / off control of the micromirror 29 is performed by the image processing unit 19 connected to the DMD 27. The light reflected by the on-state micromirror 29 is modulated into an exposure state and is incident on the second lens system 34 provided on the light exit side of the DMD 27. The light reflected by the off-state micromirror 29 is modulated into a non-exposure state and enters a light absorber (not shown).

  The second lens system 34 is disposed on the light reflection side of the DMD 27 and has a pair of lenses 34a that forms an image on the exposed surface of the substrate C to be exposed, which is reflected by the micromirror 29 that is turned on. 34b. The lens 34a and the lens 34b are arranged so that the reflective surface of the DMD 27 and the exposed surface of the exposed substrate C are in a conjugate relationship. In the present embodiment, the drawing pattern formed by the DMD 27 is set to be magnified about 5 times by the lens 34 a and the lens 34 b and imaged on the exposed surface of the substrate C to be exposed.

  On the emission side of the second lens system 34, a focusing mechanism 35 is provided for forming an image of the focal point of the light beam emitted from the second lens system 34 on the surface to be exposed of the substrate C to be exposed. The focusing mechanism 35 includes a pair of pair wedge glasses 35a and 35b. In the focusing mechanism 35, an actuator (not shown) is operated in response to a control signal from the system control unit 40, and the pair wedge glass 35a is directed along the inclined surface of the pair wedge glass 35b with respect to the pair wedge glass 35b by the actuator. The optical path length is changed by moving to, and the focus position of the light beam is changed.

  Here, the electrical system of the exposure drawing apparatus 1 according to the present embodiment will be described together with the description of the exposure head 16a.

  FIG. 7 is a configuration diagram showing an electrical system of the exposure drawing apparatus 1 according to the present embodiment. As shown in FIGS. 4 and 7, the exposure drawing apparatus 1 is provided with a system control unit 40 electrically connected to each part of the apparatus. The system control unit 40 includes a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), and a hard disk drive (HDD), and comprehensively controls each unit of the exposure drawing apparatus 1.

  The laser drive unit 41 generates a drive current having a magnitude indicated by the control signal supplied from the system control unit 40 and supplies this to the laser light source 30. The amount of light (energy) of the laser light emitted from the laser light source 30 varies according to the drive current supplied from the laser drive unit 41.

  The reflection surface drive unit 60 of the light amount adjustment unit 50 arranges one of the first reflection surface 52 and the second reflection surface 53 in the optical path in accordance with a control signal supplied from the system control unit 40. The light quantity of the light beam introduced into the rod integrator 31 is adjusted. That is, when the first reflecting surface 52 is disposed on the optical path, the light beam emitted from the laser light source 30 is introduced into the rod integrator 31 with almost no attenuation. On the other hand, when the second reflecting surface 53 is disposed on the optical path, only a part of the light beam emitted from the laser light source 30 (about 4% in this embodiment) is introduced into the rod integrator 31. .

  The stage driving unit 46 moves the stage 10 in the Y direction (scanning direction) at a moving speed indicated by the control signal supplied from the system control unit 40.

  The system control unit 40 generates a digital signal corresponding to the image data of the drawing pattern at the time of exposure drawing, and transmits the generated digital signal to the image processing unit 19. The image processing unit 19 generates a drive signal for driving the micromirror 29 of the DMD 27 of each exposure head 16 a based on the received digital signal, and supplies this to the DMD 27. By synchronizing the control signal supplied to the stage drive unit 46 by the system control unit 40 and the control signal supplied to the image processing unit 19, scanning exposure is performed in conjunction with the movement of the stage 10 and the driving of the micromirror 29. .

  The exposure drawing apparatus 1 includes a temperature detection unit 43 that detects the temperature of the DMD 27. The temperature detection unit 43 includes a temperature sensor 43 a such as a thermistor connected to the DMD 27, and transmits temperature information indicating the temperature detected by the temperature sensor 43 a to the system control unit 40.

  The exposure drawing apparatus 1 also includes a temperature adjustment unit 44 that adjusts the temperature of the DMD 27. The DMD 27 is provided with a thermoelectric element 45 such as a Peltier element. The temperature adjustment unit 44 adjusts the temperature of the DMD 27 by controlling cooling and heating of the DMD 27 by the thermoelectric element 45 based on a control signal supplied from the system control unit 40.

  When the photo sensor 26 detects the light beam emitted from the exposure head 16 a via the detection slit 25 provided in the slit plate 24, the photo sensor 26 generates a detection signal and supplies it to the system control unit 40. The system control unit 40 specifies the irradiation position of the light beam emitted from the exposure head 16 a based on the detection signal from the photosensor 26. A method for specifying the irradiation position of the light beam will be described later.

  The input unit 47 is a user interface for the operator to input the substrate size of the substrate C to be exposed, the photosensitivity of a photosensitive material such as a resist film to be exposed, an identification number for designating a drawing pattern for exposure drawing, and the like. It is composed of a keyboard and a touch panel. The operator can input processing conditions when the exposure drawing apparatus 1 performs exposure drawing as described above by operating the input unit 47. The system control unit 40 supplies control signals to the laser drive unit 41 and the reflection surface drive unit 60 so as to match the light sensitivity of the photosensitive material that is the exposure target notified via the input unit 47 to expose the substrate to be exposed. While controlling the amount (intensity) of light applied to C, a control signal is supplied to the stage drive unit 46 to control the moving speed of the stage 10 during scanning exposure.

  The display unit 48 is a display for displaying an initial information input screen or the like for an operator to input processing conditions when the exposure drawing apparatus 1 performs exposure drawing, and includes a liquid crystal display device. ing.

  The imaging unit drive mechanism 49 performs imaging by moving each of the imaging units 23 in a direction (X direction) perpendicular to the moving direction (Y direction) of the stage 10 based on a control signal from the system control unit 40. The photographing position in the unit 23 is positioned.

  As described above, in the exposure / drawing apparatus 1 according to the present embodiment, the irradiation position of the light beam irradiated on the surface to be exposed is detected for each pixel using the photosensor 26, and the actual irradiation target is detected from the detected irradiation position. A distortion amount with respect to the design drawing pattern of the drawing pattern drawn on the exposure surface is derived, and the design drawing pattern is corrected based on the derived distortion amount.

Here, in the exposure drawing device 1 according to the present embodiment, the photosensitivity dry film resist to be exposed drawing is about 10 to 100 mJ / cm ^2, if in the case of exposure with 50 mJ / cm ^2, the scanning speed (stage 10 moving speed) is 25 mm / sec and 1024 × 512 pixels are used for an exposure width of 70 mm, the amount of light per pixel is about 1.6 μW. If the amount of light for one pixel is this amount of light, the position of one pixel can be detected using the photosensor 26.

  However, when an ultra-sensitive material such as a silver salt sensitive material is used as a photosensitive material, it is necessary to reduce the amount of light beam irradiated so as to match the light sensitivity of the photosensitive material. However, even if an attempt is made to correct the irradiation position using this light beam as it is, a sufficient amount of detection signal cannot be obtained from the photosensor 26 due to insufficient light quantity of the light beam, and the S / N of the detection signal is reduced. descend. As a result, the detection accuracy of the irradiation position of the light beam is lowered, and the irradiation position cannot be appropriately corrected.

For example, when an ultrasensitive material having a photosensitivity of 0.1 mJ / cm ² is used as an exposure target, the amount of light per pixel is about 3.3 nW. Even if an attempt is made to detect such an irradiation position of a light beam with an extremely low light amount using the photosensor 26, a detection signal having a sufficiently large size cannot be obtained from the photosensor 26.

  Therefore, in the exposure drawing apparatus 1 according to the present embodiment, exposure drawing is performed on the substrate C to be exposed by controlling the reflectance in the light amount adjusting unit 50, the output of the laser light source 30, and the moving speed of the stage 10. In each case of correcting the irradiation position of the light beam, the light amount (exposure amount) of the light beam is optimized.

  Below, the effect | action of the exposure drawing apparatus 1 which concerns on this embodiment is demonstrated.

  FIG. 8 is a flowchart showing the flow of processing of the exposure control processing program executed by the system control unit 40. The program is stored in advance in a predetermined area of a ROM provided in the system control unit 40. The system control unit 40 executes the exposure control processing program, for example, when the exposure drawing apparatus 1 is turned on.

  In step S <b> 101, the system control unit 40 causes the display unit 48 to display a predetermined initial information input screen. As a result, a message prompting the operator to select either execution of exposure drawing or execution of irradiation position correction is displayed on the display unit 48. The operator operates the input unit 47 according to the message to select execution of exposure drawing or execution of irradiation position correction. When the operator instructs execution of exposure drawing, the display unit 48 displays a message prompting input of the number of processes of the substrate C to be exposed and the light sensitivity of the photosensitive material to be exposed. The operator operates the input unit 47 in accordance with such a message to input the number of processed substrates C, the light sensitivity of the photosensitive material, and the like.

  In step S102, the system control unit 40 determines whether or not to execute the irradiation position correction based on the selection result input from the input unit 47 by the operator according to the message on the initial information input screen. When the operator selects execution of irradiation position correction via the input unit 47, the system control unit 40 shifts the process to step S107, and when instructed to execute exposure drawing, the system control unit 40 proceeds to step S103. Transition.

  In step S103, the system control unit 40 derives the moving speed of the stage 10 based on the light sensitivity of the photosensitive material to be exposed, which is input by the operator from the input unit 47, and a control signal indicating the magnitude of the derived moving speed. Is supplied to the stage drive unit 46. The stage drive unit 46 that has received such a control signal moves the stage 10 in the Y direction at the moving speed indicated by the control signal.

In step S <b> 104, the system control unit 40 selects and selects the first reflection surface 52 or the second reflection surface 53 based on the light sensitivity of the photosensitive material to be exposed, which is input from the input unit 47 by the operator. A control signal is supplied to the reflecting surface driving unit 60 so as to place the reflecting surface on the optical path. The reflection surface driving unit 60 slides the base material 51 based on this control signal and arranges the first reflection surface 52 or the second reflection surface 53 on the optical path. For example, when the light sensitivity of the light-sensitive material input by the operator from the input unit 47 is equal to or higher than a predetermined value (for example, 0.5 mJ / cm ² ), the system control unit 40 is a first reflective surface having a high reflectance. 52 is arranged on the optical path, and if it is less than the predetermined value, control is performed so that the second reflecting surface 53 having a low reflectance is arranged on the optical path.

  In step S105, the system control unit 40 derives the magnitude of the drive current to be supplied to the laser light source 30 based on the light sensitivity of the photosensitive material to be exposed, which is input from the input unit 47 by the operator, and the derived drive. A control signal indicating the magnitude of the current is supplied to the laser drive unit 41. The laser drive unit 41 that has received the control signal supplies a drive current having a magnitude indicated by the control signal to the laser light source 30.

  As described above, in the exposure drawing apparatus 1 according to the present embodiment, the reflectance in the light amount adjusting unit 50 and the light emitted from the laser light source 30 are based on the light sensitivity of the photosensitive material to be exposed, which is input from the input unit 47 by the operator. The intensity of the laser beam to be applied and the moving speed of the stage 10 during scanning exposure are set.

In the exposure drawing apparatus 1 according to the present embodiment, when the first reflecting surface 52 having a reflectance of approximately 100% is arranged on the optical path, exposure can be performed with a light amount of 50 mJ / cm ^{2 at} the maximum. In addition, the amount of laser light emitted from the laser light source 30 can be adjusted in the range of 10% to 100% by the drive current supplied to the laser light source 30. Accordingly, the light amount of the exposure by adjusting the drive current can be adjusted from ^{5mJ / cm 2 ~50mJ / cm 2} . Furthermore, the moving speed of the stage 10 during scanning exposure can be adjusted within a range of 1 (standard speed) to 10 times. Therefore, by adjusting the moving speed of the stage 10 together with the adjustment of the light amount of the laser light source 30, the light amount at the time of exposure can be adjusted in the range of 0.5 mJ / cm ^{2 to} 50 mJ / cm ² .

On the other hand, when the second reflecting surface 53 having a reflectance of about 4% is arranged on the optical path, the maximum exposure amount is ² mJ / cm ² , the light amount adjustment of the laser light source 30 and the moving speed of the stage 10 are performed. With this adjustment, the amount of light at the time of exposure can be adjusted in the range of 0.02 mJ / cm ^{2 to 2} mJ / cm ² . Thus, in the exposure drawing apparatus 1 of this embodiment, exposure is performed by adjusting the reflectance in the light amount adjusting unit 50, the intensity of the laser light emitted from the laser light source 30, and the moving speed of the stage 10 during scanning exposure. It is possible to adjust the amount of light in the range of 0.02 mJ / cm ^{2 to} 50 mJ / cm ² .

  In the processing of steps S103 to S105 described above, the system control unit 40 reflects the reflectance in the light amount adjusting unit 50, the light amount (intensity) of the laser light, so that the exposure amount matches the light sensitivity of the photosensitive material to be exposed. The moving speed of the stage 10 is set. At this time, the system control unit 40 may derive the settings of the above three parameters so that the moving speed of the stage 10 is fastest from the viewpoint of improving productivity. When the system control unit 40 derives the settings of the three parameters, a reference table that associates the light sensitivity of the photosensitive material to be exposed with the settings of the three parameters may be used. In this case, the reference table is stored in advance in the ROM in the system control unit 40.

  In steps S103 to S105, when a control signal is supplied from the system control unit 40 to the stage driving unit 46, the light amount adjusting unit 50, and the laser driving unit 41, the control signal is placed on the stage 10 under conditions according to the control signal. The exposure drawing on the exposed substrate C is started.

  The laser light source 30 receives the supply of the drive current set in step S105 from the laser drive unit 41 and emits laser light. The laser light emitted from the laser light source 30 enters the light amount adjusting unit 50 as random polarized light while passing through the optical fiber 18 as a light guide. The light beam incident on the light amount adjusting unit 50 is reflected by the first reflecting surface 52 or the second reflecting surface 53 selected in step S <b> 104, and the reflected light is introduced into the rod integrator 31. The light beam is emitted from the rod integrator 31 as adjustment light adjusted so that the illuminance distribution is uniform in the rod integrator 31, and is irradiated to the DMD 27 through the first optical system 32 and the reflecting mirror 33.

  In the exposure drawing apparatus 1, when performing exposure drawing, image data indicating a drawing pattern is input to the image processing unit 19 and temporarily stored in a memory in the image processing unit 19. This image data is data representing the density of each pixel constituting the drawing pattern in binary (whether or not dots are recorded).

  The stage driving unit 46 moves the stage 10 on which the substrate to be exposed C is placed in the Y direction at the moving speed set in step S103. When the stage 10 moves to the exposure position, the image processing unit 19 sequentially reads the image data stored in the memory in the image processing unit 19 for a plurality of lines, and generates a digital signal for each exposure head 16a. The micromirror 29 of the DMD 27 of each exposure head 16a is turned on or off according to the digital signal.

  The light beam reflected by the micromirror 29 in the on state in the DMD 27 is output from the DMD 27 as pattern light corresponding to the drawing pattern, and is exposed on the substrate C to be exposed through the second lens system 34 and the focusing mechanism 35. The image is formed on the surface.

  As the substrate C to be exposed moves at a constant speed as the stage 10 moves, a strip-shaped exposed area R2 is formed for each exposure head 16a on the substrate C to be exposed. In this way, exposure drawing on the substrate C to be exposed is performed by the exposure drawing apparatus 1 according to the present embodiment. In step S106, the system control unit 40 determines whether or not the exposure drawing has been completed for the number of exposure target substrates C input by the operator via the input unit 47. Ends.

  On the other hand, when the system control unit 40 determines that the irradiation position correction is executed in step S102 and the process proceeds to step S107, the system control unit 40 in step S107, the irradiation position of the light beam emitted from the exposure head 16a. Execute correction processing. FIG. 9 is a flowchart showing a processing flow of the irradiation position correction processing program according to the present embodiment. This program is stored in advance in a predetermined area of the ROM provided in the system control unit 40.

  In step S201, the system control unit 40 supplies a control signal to the stage driving unit 46 so as to position the slit plate 24 directly below the exposure head 16a.

  In step S202, the system control unit 40 supplies a control signal to the reflection surface driving unit 60 of the light amount adjustment unit 50 so as to arrange the first reflection surface 52 having a high reflectance on the optical path.

  In step S <b> 203, the system control unit 40 supplies a control signal to the laser driving unit 41 so that the amount of light (intensity) of the laser light emitted from the laser light source 30 is maximized.

  As described above, in the irradiation position correction process of the light beam emitted from the exposure head 106a, the first reflective surface 52 having a high reflectance is disposed on the optical path, and the light amount (intensity) of the laser light from the laser light source 30 is set. Set to be maximum. Thereby, the signal level of the detection signal output from the photosensor 26 can be increased, the S / N is improved, and the detection accuracy of the irradiation position of the light beam is improved.

  In step S <b> 204, the system control unit 40 determines a pixel to be measured for correcting the irradiation position, and stores a reference irradiation position on the exposure surface of the light beam corresponding to the pixel to be measured. Note that the reference irradiation position means an ideal irradiation position of the light beam on the exposure surface corresponding to the pixel to be measured when there is no influence of distortion. When determining the pixel to be measured, it is preferable that the pixel to be measured is sequentially selected from, for example, corner pixels in the exposure region by each exposure head 16a.

  In step S205, the system control unit 40 drives the DMD 27 by inputting the position correction image data generated based on the measured pixel determined in step S204 to the image processing unit 19. This image data is image data for position correction, and is data in which the density of each pixel is expressed in binary (the pixel under measurement has dots and the other pixels have no dots). The image processing unit 19 sequentially reads the input image data for a plurality of lines, and generates a digital signal for each exposure head 16a. The micromirror 29 of the DMD 27 of each exposure head 16a is turned on or off according to the digital signal.

  In step S <b> 206, the system control unit 40 receives the output signal of the temperature detection unit 43 to acquire the temperature of the DMD 27.

  In step S207, the system control unit 40 determines whether or not the temperature acquired in step S206 is within a predetermined range. The predetermined range is that when the exposure drawing is performed and when the position correction is performed, the temperature difference of the DMD 27 is preferably ± 0.5 ° C. or less. It may be set to be −0.5 ° C. or more and 0.5 ° C. or less. Note that the temperature of the DMD 27 at the time of exposure drawing may be detected a plurality of times at an arbitrary timing while exposure drawing is being performed, and an average value of the detected temperatures may be stored in advance.

  If it is determined in step S207 that the temperature of the DMD 27 is outside the predetermined range, in step S208, the system control unit 40 causes the temperature adjustment unit 44 so that the temperature of the DMD 27 is within the predetermined range. And the process returns to step S206.

  The processes in steps S206 to S208 are processes for suppressing the thermal influence caused by changing the light amount of the light beam between exposure drawing and irradiation position correction. The temperature of the DMD 27 at the time of position correction is adjusted to substantially the same temperature as that of the DMD 27 at the time of exposure drawing.

  If it is determined in step S207 that the temperature of the DMD 27 is within a predetermined range, in step S209, the system control unit 40 determines the actual irradiation position on the exposure surface of the light beam corresponding to the pixel to be measured. get. At this time, the system control unit 40 receives the detection signal output from each of the plurality of photosensors 26, and acquires the irradiation position on the exposed surface of the light beam corresponding to the pixel under measurement from the received detection signal. .

  Here, in the exposure drawing apparatus 1 according to the present embodiment, a method for detecting the irradiation position on the exposed surface of the light beam corresponding to the pixel to be measured using the detection slit 25 will be described.

  In the exposure drawing apparatus 1 according to the present embodiment, the detection slit 25 is used for the irradiation position of the light beam irradiated on the exposed surface when the micromirror 29 corresponding to the pixel Z1 to be measured is turned on. To detect.

  FIG. 10A is a view for explaining a method for detecting the position of the pixel under measurement in the exposure drawing apparatus 1 according to the present embodiment, and FIG. 10B is an exposure drawing according to the present embodiment. FIG. 11 is a diagram illustrating a detection signal of a photosensor 26 for a pixel to be measured in the apparatus 1 corresponding to FIG.

  As shown by a solid line in FIG. 10A, the system control unit 40 moves the stage 10 in the Y direction so that the detection slit 25 becomes a required position (for example, a position to be the origin) on the exposure area R1. . At this time, the system control unit 40 sets the intersection point of the two straight portions (here, the first straight portion 25A and the second straight portion 25B) in the saddle-shaped detection slit 25 as (X0, Y0). The coordinates are temporarily stored.

  Next, as illustrated in FIG. 10A, the system control unit 40 moves the detection slit 25 in the Y direction (right side of the front view) by moving the stage 10 in the Y direction. Then, the system control unit 40 transmits the light beam corresponding to the pixel to be measured Z1 through the first linear portion 25A as shown by the two-dot chain line on the right side of the front view, that is, as shown in FIG. Then, the stage 10 is stopped at the position detected by the photosensor 26. The system control unit 40 sets the intersection of the first straight line portion 25A and the second straight line portion 25B at this time as (X0, Y11), and temporarily stores the coordinates.

  Next, the system control unit 40 moves the detection slit 25 in the Y direction (leftward in front view) by moving the stage 10 in the Y direction. The system control unit 40 then transmits the light beam of the measured pixel Z1 through the second linear portion 25B as shown by the two-dot chain line on the left side of the front view, that is, as shown in FIG. The stage 10 is stopped at the position where it is detected by the photo sensor 26. The system control unit 40 sets the intersection of the first straight line portion 25A and the second straight line portion 25B at this time as (X0, Y12), and temporarily stores the coordinates.

  Next, the system control unit 40 reads the stored coordinates (X0, Y11) and (X0, Y12), and uses these coordinates as the coordinates (X1, Y1) of the irradiation position of the light beam corresponding to the pixel to be measured Z1. Ask. Here, X1 and Y1 can be obtained as X1 = X0 + (Y11−Y12) / 2 and Y1 = (Y11 + Y12) / 2.

  As described above, when the photosensor 26 is used in combination with the detection slit 25 having the first straight portion 25A and the second straight portion 25B intersecting the first straight portion 25A, the photosensor 26 Only a predetermined range of light passing through the first straight part 25A or the second straight part 25B needs to be detected. Therefore, in this configuration, a commercially available inexpensive photosensor is used without making the photosensor 26 a fine and special configuration that detects a light amount in a narrow range corresponding to the first linear portion 25A or the second linear portion 25B. it can.

  In step S210, the system control unit 40 compares the reference irradiation position of the pixel under measurement stored in step S204 with the actual irradiation position of the light beam corresponding to the pixel under measurement acquired in step S209, and performs reference irradiation. A deviation amount of the actual irradiation position with respect to the position is derived and stored.

  In step S <b> 211, the system control unit 40 determines whether or not the derivation of the deviation amount has been completed for all the pixels under measurement for which the deviation amount should be derived. If the system control unit 40 determines that the derivation of the deviation amount has not been completed for all the pixels under measurement for which the deviation amount should be derived, the system control unit 40 returns the process to step S204, and all the measurement subjects for which the deviation amount should be derived. If it is determined that the derivation of the shift amount has been completed for the pixel, the process proceeds to step S212.

  In step S212, the system control unit 40 corrects the image data of the design drawing pattern based on the shift amount of each pixel to be measured derived in step S210, thereby irradiating the irradiation position of the light beam emitted from the exposure head 16a. Correct. The correction of the irradiation position of the light beam can be performed by modifying the design drawing pattern according to the shift amount, changing the mapping between each pixel of the design drawing pattern and each micromirror 29 in the DMD 27, or the like. That is, a distortion amount with respect to the design drawing pattern of the drawing pattern actually drawn is derived based on the derived deviation amount, and the image data of the design drawing pattern is corrected so that the derived distortion amount is reduced, or the micromirror 29 And the correspondence relationship between the pixels of the image data of the design drawing pattern is corrected.

  FIG. 11 is a schematic view showing an example of exposure drawing distortion correction in the exposure drawing apparatus 1 according to the present embodiment.

  If there is no distortion in the plurality of optical systems and the substrate C to be exposed, the image data of the design drawing pattern input to the DMD 27 is exposed as it is even if it is not particularly corrected as shown in FIG. By exposure drawing on the substrate C, an ideal image is drawn as shown in FIG.

  However, when distortion or the like occurs in the drawing pattern due to the influence of distortion or the like in the optical system in the exposure head 16a, the image data of the design drawing pattern is used as it is without correcting the image as shown in FIG. When input to the DMD 27, the drawing pattern actually drawn is deformed as shown in FIG. 11C.

  Therefore, as shown in FIG. 11F, the image data of the design drawing pattern input to the DMD 27 is corrected to correct the irradiation position of the light beam corresponding to each pixel, as shown in FIG. Finally, a correct image without distortion is drawn.

As is clear from the above description, in the exposure drawing apparatus 1 according to the present embodiment, the reflectance in the light amount adjustment unit 50, the intensity of the laser light emitted from the laser light source 30, and the movement of the stage 10 during scanning exposure. By adjusting the speed, the amount (energy) of light emitted from the exposure head 16a can be adjusted over a wide range (0.02 mJ / cm ^{2 to} 50 mJ / cm ² ). That is, the exposure amount can be adjusted in a wide range of 2500 times. Thereby, exposure drawing can be performed on photosensitive materials having various photosensitivities including the ultrasensitive photosensitive material. Further, even when the irradiation position correction of the light beam emitted from the exposure head 16a is performed using the photosensor 26, a detection signal with sufficient intensity can be obtained from the photosensor 26 by increasing the light amount of the exposure head 16a. Can do. Therefore, it is possible to avoid the problem that the irradiation position detection accuracy is lowered due to insufficient light quantity. That is, according to the exposure drawing apparatus 1 according to the present embodiment, it is possible to achieve both exposure drawing on the ultrasensitive material and correction of the irradiation position of the light beam emitted from the exposure head 16a.

  Further, in the exposure drawing apparatus 1 according to the present embodiment, in order to greatly attenuate the light amount of the light beam emitted from the laser light source 30, the non-coated surface of the base material 51 made of glass having a refractive index of about 1.5 (second). The reflected light reflected by the reflecting surface 53) is used. The reflectance of the second reflecting surface 53 depends only on the refractive index of the base material 51, the incident angle of light, and the polarization state of incident light. In the case of random polarization, the variation in reflectance is 4% ± 0.2. %. As a result, the variation in the light amount of the light beam output from the light amount adjusting unit 50 can be suppressed to about ± 5%. In this way, by using the light amount adjusting unit 50 that outputs the reflected light reflected by the low-reflectance reflecting surface as a means for attenuating the light amount of the light beam, compared to the case of using a transmission type attenuator, Variations in the amount of light can be reduced. In particular, the effect becomes significant when the amount of light beam is greatly attenuated.

  Further, in the exposure apparatus 1 according to the present embodiment, the rod integrator 31 that equalizes the illuminance distribution in the beam cross section of the light beam is arranged at the rear stage of the light amount adjusting unit 50, so that the arrangement is compared with the case where these arrangements are replaced. Thus, the uniformity of the illuminance distribution of the light beam can be improved.

  In the exposure drawing apparatus 1 according to the present embodiment, either the first reflective surface 52 having a high reflectance or the second reflective surface 53 having a low reflectance is arranged on the optical path. One or a plurality of reflecting surfaces having an intermediate reflectance may be provided. In this case, a desired reflectance can be obtained by appropriately selecting a reflective film that covers the substrate 51.

  Moreover, in the exposure drawing apparatus 1 which concerns on this embodiment, in the light quantity adjustment part 50, although the case where the 1st reflective surface 52 and the 2nd reflective surface 53 were formed on the single base material 51 was illustrated, these The reflective surface of each may be formed on a separate substrate.

  Moreover, in the exposure drawing apparatus 1 which concerns on this embodiment, although the Peltier device is used as the temperature control member 45, it is not limited to this, A fan etc. which cools may be sufficient.

  In the exposure drawing apparatus 1 according to the present embodiment, the DMD 27 is used as a spatial light modulation element used for the exposure head 16a. For example, a micro electro mechanical systems (MEMS) type spatial light modulation element (SLM; Special Light) is used. A spatial light modulator other than the MEMS type, such as a modulator, an optical element (PLZT element) that modulates transmitted light by an electro-optic effect, or a liquid crystal light shutter (FLC), may be used instead of the DMD 27.

Note that MEMS is a general term for a micro system that integrates micro-sized sensors, actuators, and control circuits based on a micro-machining technology based on an IC manufacturing process, and a MEMS type spatial light modulator is an electrostatic force. It means a spatial light modulation element driven by an electromechanical operation using
[Second Embodiment]
Hereinafter, an exposure drawing apparatus according to the second embodiment of the present invention will be described in detail. The exposure drawing apparatus according to the second embodiment includes a light amount adjustment unit having a configuration different from that of the light amount adjustment unit 50 according to the first embodiment. Since the configuration other than the light amount adjustment unit is the same as that of the first embodiment described above, a description thereof will be omitted.

  In the light amount adjustment unit 50 according to the first embodiment, either one of the high-reflectivity first reflective surface 52 and the low-reflectivity second reflective surface 53 is selectively disposed on the optical path. The light quantity of the light beam emitted from the exposure head 16a is adjusted. On the other hand, the light amount adjustment unit 50a according to the present embodiment has a single light reflection surface, and changes the reflectance by changing the incident angle of the light beam incident on the light reflection surface. This adjusts the amount of reflected light.

  FIG. 12 is a cross-sectional view along the optical path of the light beam showing the configuration of the light amount adjusting unit 50a according to the second embodiment of the present invention. The light amount adjusting unit 50a according to the present embodiment is connected to the base 51 made of a light transmissive member such as glass having a refractive index of about 1.5, a support plate 54 that supports the base 51, and the support plate 54. And a rotation drive mechanism (not shown) that rotates the rotation shaft portion 55 around its axis based on a control signal supplied from the system control unit 40.

The entire surface of the substrate 51 is a glass surface that is not coated, and the surface of the substrate 51 is a reflective surface 56. When the rotation shaft portion 55 rotates around the axis, the direction of the reflection surface 56 changes as shown in FIGS. 12A to 12C, and the light beam emitted from the laser light source 30 is reflected. The incident angle θ _i with respect to the surface 56 changes.

The reflectance at the reflecting surface 56 changes according to the incident angle θ _i of the light beam. FIG. 13 is a graph showing the relationship between the incident angle θ _i and the reflectance of the reflection surface 56 for each of the p-polarization plane and the s-polarization plane. As shown in FIG. 13, when glass having a refractive index of about 1.5 is used as the substrate 51, the reflectance at the reflecting surface 56 varies in the range of about 4% to 100% depending on the incident angle θ _i. . That is, as shown in FIGS. 12A to 12C, the reflectance of the reflection surface 56 is changed from about 4% by controlling the rotation angle of the rotation shaft portion 55 to change the direction of the reflection surface 56. It can be changed within a range of 100%. As described above, the light amount adjusting unit 50 a according to the present embodiment can adjust the light amount of the light beam by controlling the incident angle θ _i of the light beam with respect to the reflection surface 56.

Note that the traveling direction of the reflected light is changed by changing the incident angle θ _i of the light beam with respect to the reflecting surface 56, but the reflecting surface 56 and the light incident surface of the rod integrator 31 are connected to the condenser lens 70. With respect to the arrangement, the reflected light can be introduced into the rod integrator 31 even if the traveling direction of the reflected light fluctuates.

  As described above, according to the exposure drawing apparatus according to the present embodiment, similarly to the exposure drawing apparatus according to the first embodiment, the exposure drawing on the ultrasensitive material and the irradiation of the light beam emitted from the exposure head 16a. It is possible to achieve both position correction. Further, even when exposure drawing is performed with an extremely low amount of light, variation in the amount of light can be reduced. Furthermore, according to the light amount adjusting unit 50a according to the present embodiment, the reflectance at the reflecting surface 56 can be continuously changed by changing the incident angle θi of the light beam with respect to the reflecting surface 56, so that the amount of exposure can be reduced. Adjustment can be made more flexibly.

  DESCRIPTION OF SYMBOLS 1 ... Exposure drawing apparatus, 10 ... Stage, 11 ... Base | substrate, 12 ... Base, 13 ... Movement mechanism part, 16 ... Exposure part, 16a ... Exposure head, 17 ... Light source unit, 18 ... Optical fiber, 19 ... Image processing unit , 24 ... slit plate, 25 ... detection slit, 26 ... photosensor, 27 ... DMD, 29 ... micromirror, 30 ... laser light source, 31 ... rod integrator, 32 ... first lens system, 33 ... reflector, 34 ... Second lens system, 35 ... Focusing mechanism, 40 ... System control unit, 41 ... Laser drive unit, 43 ... Temperature detection unit, 44 ... Temperature adjustment unit, 46 ... Stage drive unit, 47 ... Input unit, 48 ... Display Reference numeral 49, a photographing unit drive mechanism, 50, a light amount adjusting unit, 51, a base material, 52, a first reflecting surface, 53, a second reflecting surface, 80, a light absorbing unit, C, a substrate to be exposed.

Claims (17)

A light source;
A light amount adjustment unit that has a reflection surface that reflects light reflected from the light source and that emits reflected light of a light amount corresponding to the reflectance of the reflection surface;
A first optical system that introduces the reflected light and adjusts an illuminance distribution of the reflected light to generate adjustment light;
A light modulation unit that spatially modulates the adjustment light to generate pattern light corresponding to a drawing pattern;
A second optical system for imaging the pattern light on an exposed surface;
Exposure drawing apparatus. The light amount adjusting unit is
A plurality of reflecting surfaces having different reflectances;
A drive unit that arranges any of the plurality of reflecting surfaces on the optical path in response to a control signal;
The exposure drawing apparatus according to claim 1, comprising: The light amount adjusting unit is
A first reflecting surface constituted by the surface of the light reflecting member;
The exposure drawing apparatus according to claim 2, further comprising: a second reflection surface having a reflectance lower than that of the first reflection surface configured by a surface of the light transmissive member.   The exposure drawing apparatus according to claim 3, wherein the second reflecting surface is formed of a glass surface. The first reflecting surface is composed of a light reflecting film that covers the surface of a substrate made of glass,
The exposure drawing apparatus according to claim 4, wherein the second reflecting surface is constituted by a non-coated surface of the base material. The light amount adjusting unit is
A reflective surface composed of the surface of a light transmissive member;
A drive unit that changes an incident angle of light from the light source with respect to the reflection surface according to a control signal,
The exposure drawing apparatus according to claim 1, wherein the reflectance at the reflecting surface changes according to an incident angle of light from the light source. Obtaining means for obtaining information relating to light sensitivity on the exposed surface;
The exposure drawing apparatus according to any one of claims 1 to 6, further comprising: a first control unit that controls a reflectance on the reflecting surface in accordance with information acquired by the acquisition unit.   The exposure drawing apparatus according to claim 7, further comprising second control means for controlling intensity of light generated in the light source according to information acquired by the acquisition means.   The exposure drawing apparatus according to claim 8, further comprising third control means for controlling a moving speed of a stage on which an exposure target having the exposed surface is placed according to information acquired by the acquisition means. A detection surface provided in the same plane as the exposed surface;
An irradiation position detecting means for detecting an irradiation position of the pattern light on the detection surface;
The exposure drawing according to any one of claims 1 to 9, further comprising: a correction unit that corrects the irradiation position of the pattern light based on the irradiation position of the pattern light detected by the irradiation position detection unit. apparatus.   The exposure drawing apparatus according to claim 1, wherein the first optical system includes a rod integrator.   A condensing lens disposed between the light amount adjusting unit and the rod integrator, wherein the reflecting surface of the light amount adjusting unit and the light incident surface of the rod integrator are conjugate to the condensing lens; The exposure drawing apparatus according to claim 11, which is disposed in   The exposure drawing apparatus according to claim 1, further comprising a temperature adjusting unit that maintains a temperature of the light modulation unit within a predetermined range.   The exposure drawing apparatus according to claim 1, wherein the light source includes a laser that emits laser light.   The exposure drawing apparatus according to claim 14, further comprising a light guide that generates random polarized light from the laser light and guides the polarized light to the reflecting surface.   The exposure drawing apparatus according to claim 1, further comprising a light absorbing member that absorbs light transmitted through the reflecting surface. Computer
Obtaining means for obtaining information on the photosensitivity of the exposed surface;
First control means for controlling the reflectance at the reflecting surface according to the information obtained by the obtaining means;
Second control means for controlling the intensity of light generated in the light source according to the information acquired by the acquisition means;
2. The exposure drawing apparatus according to claim 1, wherein the exposure drawing apparatus according to claim 1 is made to function as a third control unit that controls a moving speed of a stage on which an exposure target having the exposed surface is placed according to information acquired by the acquisition unit. A program to control.

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