WO2014002312A1

WO2014002312A1 - Pattern drawing device, pattern drawing method

Info

Publication number: WO2014002312A1
Application number: PCT/JP2012/082758
Authority: WO
Inventors: 小久保　正彦; 昌一馬越; 大介岸脇; 康平大森
Original assignee: 大日本スクリーン製造株式会社
Priority date: 2012-06-26
Filing date: 2012-12-18
Publication date: 2014-01-03
Also published as: TW201400989A; JP2014006433A; TWI479279B

Abstract

The uniformity of the illumination distribution of irradiation light (Re) on a substrate (S) may be improved for a pattern drawing device (1) wherein light incident on a spatial modulator (80) through a rod integrator (70) is modulated by a spatial light modulator (80) and irradiated onto the substrate (S). Provided is a light source array (60) having a plurality of light-emitting elements (601) which emits light with the brightness in accordance with the magnitude of a driving current (Id). The rod integrator (70) equalizes the illumination distribution for the light entering from the light source array (60). Also provided is an irradiation control unit (130) which individually controls the magnitude of the driving signal (Id) for each light-emitting element (601). Therefore, by individually controlling the brightness of the light-emitting element (601) the illumination distribution of the light incident on the subsequent rod integrator (70) can be suitably adjusted. As a result, it is possible to improve the uniformity of the illumination distribution of the irradiation light on an irradiation region (Re) using an optical head (6).

Description

Pattern drawing apparatus and pattern drawing method

The present invention relates to a pattern drawing apparatus and a pattern drawing method in which light incident on a spatial light modulator via an illuminance equalizing element is modulated by the spatial light modulator and irradiated onto a substrate.

Conventionally, there has been known a pattern drawing apparatus that exposes a drawing target such as a substrate coated with a photosensitive material such as a resist solution in a pattern and draws a pattern on the drawing target. Further, in the pattern drawing apparatus of Patent Document 1, a spatial light modulator composed of DMD (Digital Micromirror Device) is provided, and this spatial light modulator has a pattern to form light from an ultrahigh pressure mercury lamp. The pattern is drawn on the drawing target by modulating the light accordingly and irradiating the drawing target.

Incidentally, in such a pattern writing apparatus, it is required that the illuminance distribution of the light irradiated to the drawing target is uniform in order to form a pattern without unevenness. Therefore, in Patent Document 1, an integrator, which is an illuminance uniformizing element, is provided in the optical path from the ultrahigh pressure mercury lamp to the spatial light modulator, and light with improved illuminance distribution uniformity by the function of the integrator is provided. The spatial light modulator is irradiated. Thereby, the illuminance distribution of the light irradiated to the drawing target is made uniform.

JP 2006-337475 A

However, the luminance distribution of the emission point of the ultra-high pressure mercury lamp is not necessarily uniform and may have unevenness, which is condensed by an optical system such as an elliptical mirror and led to an illuminance uniformizing element such as an integrator. As a result, a large unevenness occurs in the illuminance distribution at the integrator incident end. Further, even when a bundle fiber in which individual fibers are randomly arranged is used to guide the light from the lamp house to the integrator, the illuminance distribution at the integrator incident end may not be made uniform. Thus, when the illuminance distribution at the integrator incident end is uneven, the ability of the integrator to make the illuminance distribution uniform is limited. Therefore, if the unevenness is large, the uniformity of the illuminance distribution of the light applied to the drawing target cannot always be sufficiently ensured. That is, if the illuminance distribution at the integrator incident end is too large to be compensated for by the ability of the integrator, the illuminance distribution of the light irradiated to the drawing target may not be uniform. Alternatively, if the integrator itself has manufacturing errors and its function is low, or the uniformity of the illuminance distribution of the light irradiated to the drawing object due to unevenness of the transmittance and reflectance of the optical elements in the optical path may be insufficient there were.

The present invention has been made in view of the above problems, and a pattern drawing apparatus and a pattern drawing method for irradiating an object to be drawn by modulating light incident on a spatial light modulator via an illuminance uniformizing element with the spatial light modulator In addition, in addition to the capability of the illuminance uniformizing element, an object of the present invention is to provide a technique that can improve the uniformity of the illuminance distribution of the irradiation light to the drawing target.

In order to achieve the above object, a pattern drawing apparatus according to the present invention provides a light emitting unit having a plurality of light emitting units that emit light at a luminance corresponding to the magnitude of a drive signal, and light incident from the light emitting unit to emit light illuminance. The illuminance uniformity element that emits after uniforming the distribution, the spatial light modulator that modulates the light emitted from the illuminance uniformity element and irradiates the drawing object, and the size of the drive signal for each light emitting unit individually And a drive control unit for controlling.

In the invention (pattern drawing apparatus) configured as described above, a light emitting unit having a plurality of light emitting units that emit light with luminance according to the magnitude of the drive signal is provided, and the illuminance equalizing element has been incident from the light emitting unit. The illuminance distribution is made uniform with respect to light. And in this invention, the drive control part which controls the magnitude | size of a drive signal separately for every light emission part is provided. Therefore, it is possible to appropriately adjust the illuminance distribution of the light incident on the illuminance uniformizing element by individually controlling the luminance for each light emitting unit. As a result, in addition to the ability of the illuminance uniformizing element, it is possible to improve the uniformity of the illuminance distribution of the irradiation light on the drawing target.

By the way, in a pattern drawing apparatus that draws a pattern on a drawing object by modulating the light emitted from the light emitting unit to the spatial light modulator while relatively moving the light emitting unit in the first direction with respect to the drawing object, The unit can configure the pattern drawing device so that light is irradiated to different positions in a second direction orthogonal to the first direction. In such a configuration, when the illuminance unevenness of the light irradiated to the drawing target is generated in the second direction, a difference in the exposure amount distribution appears on the drawing target, which is not preferable. On the other hand, if the configuration is such that the magnitude of the drive signal is individually controlled for each light emitting unit as described above, it is possible to effectively suppress the occurrence of such illuminance unevenness in the second direction. Is possible.

Specifically, the pattern drawing device may be configured such that the plurality of light emitting units irradiate light at different positions in the second direction with respect to the illumination uniformizing element incident end. In such a configuration, the illuminance distribution of the light incident on the illuminance equalizing element incident end can be changed in the second direction by individually controlling the magnitude of the drive signal for each light emitting unit. At this time, if the illuminance distribution at the incident end of the illuminance uniforming element changes in the second direction, the illuminance distribution slightly changes in the second direction at the outgoing end of the illuminance uniformizing element accordingly. Therefore, by utilizing such characteristics of the illuminance uniformizing element, the magnitude of the drive signal can be individually controlled for each light emitting unit to adjust the illuminance distribution of light after the illuminance uniforming element emission end. It is possible to effectively suppress the occurrence of uneven illuminance in the second direction described above.

At this time, the light emitting unit is configured by a plurality of light emitting elements each emitting light with a luminance corresponding to the magnitude of the drive signal and irradiating light to the positions arranged in a straight line in the first direction. The patterning device may be configured to collectively control the magnitude of the drive signal for a plurality of light emitting elements belonging to the same light emitting unit. In such a configuration, the regions where the light emitting elements belonging to the same light emitting unit emit light are aligned in the direction in which the light emitting unit moves relative to the drawing target (first direction). For this reason, the plurality of light emitting elements belonging to the same light emitting unit irradiate light while moving in the first direction with respect to the drawing target, thereby performing exposure in the direction of integration in the same region. Therefore, even if the illumination light of each of these light emitting elements has uneven illuminance, there is little influence on the finally formed pattern. Therefore, it is possible to simplify the drive control by collectively controlling the magnitude of the drive signal for a plurality of light emitting elements belonging to the same light emitting unit.

Specifically, each of the light emitting units emits light with a luminance corresponding to the magnitude of the drive signal, and each of the light emitting units irradiates light at positions linearly aligned in the first direction at the illuminance equalizing element incident end. The pattern drawing apparatus may be configured such that the drive control unit is configured by a light emitting element, and the control of the magnitude of the drive signal is collectively performed for a plurality of light emitting elements belonging to the same light emitting unit. In such a configuration, a region where a plurality of light emitting elements belonging to the same light emitting unit emit light is aligned in a direction (first direction) in which the light emitting unit relatively moves with respect to the drawing target at the illuminance equalizing element incident end. It will be out. For this reason, the plurality of light emitting elements belonging to the same light emitting unit irradiate light while moving in the first direction with respect to the drawing target, thereby performing exposure in the direction of integration in the same region. Therefore, even if the illumination light of each of these light emitting elements has uneven illuminance, there is little influence on the finally formed pattern. Therefore, it is possible to simplify the drive control by collectively controlling the magnitude of the drive signal for a plurality of light emitting elements belonging to the same light emitting unit.

In addition, an illuminance detector that detects an illuminance distribution of the light emitted from the illuminance equalizing element is further provided, and the drive control unit determines the magnitude of the drive signal for each light emitting unit according to the detection result of the illuminance detector. Alternatively, the pattern drawing device may be configured to be individually controlled. In such a configuration, since the magnitude of the drive signal to each light emitting unit is controlled based on the result of detecting the illuminance distribution of the light emitted from the illuminance equalizing element, the irradiation light to the drawing target The uniformity of the illuminance distribution can be improved more reliably.

At this time, the illuminance detector may configure the pattern drawing device so as to detect the illuminance distribution of the light irradiated to the drawing target. Thereby, the uniformity of the illuminance distribution of the irradiation light to the drawing target can be further improved.

Various types of spatial light modulators can be used. Therefore, the pattern drawing device may be configured so that the spatial light modulator is a DMD.

In addition, in order to achieve the above object, the pattern drawing method according to the present invention individually controls the magnitude of the drive signal given to the plurality of light emitting sections that emit light with the luminance corresponding to the magnitude of the drive signal. A step of making the light from a plurality of light emitting portions incident on an illuminance uniformizing element that homogenizes and emits incident light, and modulating the light emitted from the illuminance uniformizing element with a spatial light modulator And a step of irradiating the drawing target.

In the invention configured as described above (pattern drawing method), a plurality of light emitting portions that emit light at a luminance corresponding to the magnitude of the drive signal are provided, and the illuminance equalizing element applies to light incident from the plurality of light emitting portions. On the other hand, the illuminance distribution is made uniform. And in this invention, the process of controlling the magnitude | size of a drive signal separately for every light emission part is provided. Therefore, it is possible to appropriately adjust the illuminance distribution of the light incident on the illuminance uniformizing element by individually controlling the luminance for each light emitting unit. As a result, in addition to the ability of the illuminance uniformizing element, it is possible to improve the uniformity of the illuminance distribution of the irradiation light on the drawing target.

According to the present invention, in a pattern drawing apparatus and a pattern drawing method in which light incident on a spatial light modulator via an illuminance equalizing element is modulated by the spatial light modulator and irradiated to a drawing object, In addition to the capability, it is possible to improve the uniformity of the illuminance distribution of the irradiation light on the drawing target.

It is a side view which shows typically an example of the pattern drawing apparatus which can apply this invention. FIG. 2 is a partial plan view schematically showing the pattern drawing apparatus of FIG. 1. It is a fragmentary top view which shows the conveyance mechanism of an optical sensor. It is a perspective view which shows typically the schematic structure with which an optical head is provided. It is a side view which shows typically schematic structure of a light source panel. It is a top view which shows typically schematic structure of a light source panel. It is a perspective view which shows typically schematic structure of a light source panel. It is the figure which showed the light ray figure of the light which injects into a rod integrator. It is the top view which showed typically an example of the image of the light emitting element irradiated to a rod integrator. It is a block diagram which shows an example of the circuit which controls a light emitting element separately.

FIG. 1 is a side view schematically showing an example of a pattern drawing apparatus to which the present invention is applicable. FIG. 2 is a partial plan view schematically showing the pattern drawing apparatus of FIG. FIG. 3 is a partial plan view showing the transport mechanism of the optical sensor. In order to show the positional relationship of each part of the pattern drawing apparatus 1, in these drawings, XYZ orthogonal coordinate axes having the Z-axis direction as the vertical direction are appropriately shown. Further, as necessary, the arrow side of each coordinate axis in the drawing is referred to as a positive side, and the opposite side of each coordinate axis in the drawing is referred to as a negative side.

The pattern drawing apparatus 1 performs pattern drawing by exposure on the substrate S carried into the apparatus from the negative inlet 11 in the Y-axis direction, and the pattern has been drawn from the positive outlet 12 in the Y-axis direction. The substrate S is unloaded. The substrate S is a surface of a semiconductor substrate, an FPC (Flexible Printed Circuit) substrate, a plasma display device, an organic EL (Electro-Luminescence) display device, or the like on which an upper surface (one main surface) is coated with a photosensitive material such as a resist solution. A glass substrate for a display device or a printed wiring board. The pattern drawing apparatus 1 includes a support unit 3 that supports a substrate S that has been carried in, an exposure unit 5 that exposes the substrate S supported by the support unit 3, and an imaging unit 9 that captures an alignment mark on the substrate S. , And a controller 100 that controls each

unit

3, 5, 9.

The support unit 3 is provided with a support stage 31 that sucks and supports the substrate S placed on the upper surface thereof, and a pair of peeling rollers 32 provided on both sides of the support stage 31 in the Y-axis direction. That is, the support stage 31 has a large number of suction holes on a horizontally formed upper surface, and a substrate placed on the upper surface of the support stage 31 by suction of each suction hole by a suction mechanism (not shown). S is adsorbed to the support stage. As a result, the substrate S that has been carried in is firmly supported by the support stage 31, and pattern drawing on the substrate S can be executed stably. Further, when the substrate S is unloaded after the pattern drawing is finished, the suction of the suction holes is stopped and the pair of peeling rollers 32 are raised to push up the substrate S, whereby the substrate S is peeled from the support stage 31. The

Further, in the support unit 3, the support stage 31 is connected to the mover 37 a of the linear motor 37 through the lifting table 33, the rotary table 34 and the support plate 35. Therefore, the support stage 31 can be moved up and down by the lift table 33 and can be rotated by the rotary table 34. Furthermore, by driving the mover 37a along the stator 37b of the linear motor 37 extending in the Y-axis direction, the support stage 31 can be driven in the Y-axis direction in the range from the carry-in port 11 to the carry-out port 12. . A pair of peeling rollers 32 is also moved along with the support stage 31.

Further, as shown in FIG. 3, the support stage 31 includes an optical sensor SC that detects an illuminance distribution of the light irradiated by the optical head 6 on the surface of the substrate S supported by the support stage 31 (a position corresponding to the support stage 31), and A transport mechanism 20 that moves the optical sensor SC in the X-axis direction is provided at the front end of the support stage 31 in the Y-axis direction. The optical sensor SC is disposed on the upper surface of the support stage 31 and on the (+ Y) side of the support stage 31. As will be apparent later, when the operation of adjusting the illuminance distribution of light by the optical head 6 is performed, the support stage 31 is moved along the main scanning direction (Y-axis direction), thereby the optical head 6. Is placed directly above the optical sensor SC.

The optical sensor SC has a structure in which a pinhole, a diffusion plate, and a photodiode as a light receiving element are arranged inside the housing 41. The modulated light of the two-dimensional region irradiated from the optical head 6 is introduced into the housing 41 and the amount of light is detected. The transport mechanism 20 is fixed on the ball screw 21 and the support stage 31 arranged in the sub-scanning direction (X-axis direction) and two guide rails 22 arranged in the sub-scanning direction for supporting the housing 41. And a motor 23 connected to the ball screw 21.

In the pattern drawing apparatus 1, the ball screw 21 is rotated by the motor 23 of the transport mechanism 20 and the optical sensor SC is moved along the guide rail 22, that is, along the sub-scanning direction, in the operation of detecting the illuminance distribution of light described later. Is moved in a predetermined direction. Thereby, the modulated light emitted from the optical head 6 is sequentially received and detected for each light emitting element 601 by the photodiode of the optical sensor SC. The detected optical signals are transmitted to and stored in the irradiation control unit 130, and predetermined calculation processing is performed.

In addition, here, the optical sensor SC moves while the optical sensor SC receives light, and the transport mechanism 20 is driven to detect light. However, the specific form for detecting light is not limited to this. Therefore, the transport mechanism 20 may not be provided, and the optical sensor SC may be fixedly installed with respect to the support stage 31. In this case, the optical sensor SC moves relative to the optical head 6 to detect light by the movement of the support stage 31 in the main scanning direction and the support table 51 in the sub-scanning direction.

The exposure unit 5 has a plurality of optical heads 6 arranged on the upper side with respect to the movable region of the support stage 31. Each optical head 6 exposes the substrate S by emitting light toward the substrate S supported by the support stage 31 below. The plurality of optical heads 6 are arranged side by side in the X-axis direction, and are responsible for exposing different areas in the X-axis direction. The support table 51 that supports the plurality of optical heads 6 is movable along a pair of linear guides 52 extending in the X-axis direction. Therefore, by driving the support table along the linear guide 52 by a linear motor (not shown), the plurality of optical heads 6 can be collectively moved in the X-axis direction.

The imaging unit 9 has two CCD (Charge Coupled Device) cameras 91 arranged at intervals in the X-axis direction. These CCD cameras 91 are configured to be movable in the X-axis direction by a driving mechanism (not shown), and move above the alignment mark formed on the substrate S to image the alignment mark.

The above is the outline of the mechanical configuration of the pattern drawing apparatus 1. Next, the controller 100 that is an electrical configuration of the pattern drawing apparatus 1 will be described. The controller 100 mainly performs an operation of scanning the surface of the substrate S supported by the support stage 31 with the irradiation light from the optical head 6 and drawing a pattern on the surface of the substrate S. A control unit 120 and an irradiation control unit 130 are included.

The data processing unit 110 converts image data generated by CAD (computer aided design) or the like into drawing data and outputs it to the scanning control unit 120. On the other hand, the scanning control unit 120 controls the movement of the support stage 31 and the optical head 6 during the pattern drawing operation based on the drawing data. The irradiation control unit 130 controls light irradiation of the optical head 6 during the pattern drawing operation. More specifically, the pattern drawing operation is executed as follows.

In starting the pattern drawing operation, the controller 100 causes the imaging unit 9 to image the alignment mark attached to the substrate S. Then, the controller 100 adjusts the positional relationship between the support stage 31 and the optical head 6 based on the imaging result of the imaging unit 9, so that a plurality of optical devices are positioned at positions where exposure to the substrate S on the support stage 31 is started. The head 6 is positioned.

When this positioning is completed, the support stage 31 starts moving to one side in the Y-axis direction (for example, the Y-axis negative side). Then, each of the plurality of optical heads 6 irradiates the surface of the substrate S that moves along with the support stage 31 with a pattern according to the drawing data. Thus, each of the plurality of optical heads 6 scans the surface of the substrate S with irradiation light in the Y-axis direction (main scanning direction), thereby forming a pattern for one line (line pattern) on the surface of the substrate S. In this way, a plurality of line patterns corresponding to the number of optical heads 6 are formed side by side in the X-axis direction.

When the formation of the plurality of line patterns is completed, the controller 100 moves the optical head 6 in the X-axis direction (sub-scanning direction). Accordingly, each of the plurality of optical heads 6 is opposed to the previously formed plurality of line patterns. When the support stage 31 starts to move to the other side in the Y-axis direction (for example, the Y-axis positive side) that is the opposite side to the previous stage, a plurality of the support stage 31 moves with respect to the surface of the substrate S that moves with the support stage 31. Each of the optical heads 6 irradiates light of a pattern corresponding to the drawing data.

Thus, the irradiation light of the optical head 6 is scanned between each of the plurality of previously formed line patterns, and a new line pattern is formed. In this way, a pattern is drawn on the entire surface of the substrate S by sequentially forming a plurality of line patterns while intermittently moving the optical head 6 in the X-axis direction.

The above is the outline of the pattern drawing apparatus 1. Next, details of the optical head 6 will be described. Since the plurality of optical heads 6 have the same configuration, only one optical head 6 will be described here. FIG. 4 is a perspective view schematically showing a schematic configuration of the optical head.

The optical head 6 makes light emitted from the light source array 60 enter a spatial light modulator 80 that is a light modulator via a rod integrator 70 that is a rod-like integrator, and is spatially modulated by the spatial light modulator 80. Is applied to the irradiation region Re on the surface of the substrate S. As shown in FIG. 4, the optical head 6 is provided with two light source arrays 60, and a lens array 61 is disposed opposite to each of the light source arrays 60. The light source array 60 and the lens array 61 facing each other are integrated as a light source panel 62.

FIG. 5 is a side view schematically showing a schematic configuration of the light source panel. FIG. 6 is a plan view schematically showing a schematic configuration of the light source panel. FIG. 7 is a perspective view schematically showing a schematic configuration of the light source panel. In these drawings, symbol Aoa indicates the optical axis direction of the optical head 6. Note that the two light source panels 62 differ only in the wavelength of light emitted from the light emitting elements, and the other configurations are the same. Therefore, the following description is basically made by showing one light source panel 62. As shown in FIGS. 5 to 7, the light source array 60 of the light source panel 62 has a configuration in which twelve light emitting elements 601 are two-dimensionally arranged in three rows and four columns on a flat electrode substrate 602. At this time, the intervals between adjacent light emitting elements 601 are equal in both the row direction and the column direction, and the plurality of light emitting elements 601 are uniformly arranged. Here, a set of three light emitting elements 601 arranged in the column direction is particularly referred to as a light emitting element column 601C.

Each light emitting element 601 emits light with a luminance corresponding to the drive current Id (FIG. 1), and specifically, an LED (Light
Emitting Diode) bare chip. That is, in this embodiment, a plurality of LEDs are used side by side. More specifically, the light emitting element 601 is configured by a ceramic package in which an LED chip having a square light emitting region is housed. A cover glass for protecting the inside is provided on the front surface of each ceramic package.

Thus, one reason for using a plurality of LEDs side by side is as follows. Conventionally, it has been common to use an ultra-high pressure mercury lamp as a light source. On the other hand, LEDs have advantages such as high efficiency, long life, monochromatic light emission, and space saving over such an ultra-high pressure mercury lamp. In this embodiment, attention is given to such advantages, and LEDs are used as light sources. However, with a single LED, the amount of light required for exposure may be insufficient. Therefore, securing a sufficient amount of light is achieved by arranging a plurality of LEDs. Moreover, since the LED is remarkably small as compared with the ultra-high pressure mercury lamp, the advantage of saving space is not impaired even when a plurality of LEDs are arranged. Thus, this embodiment effectively draws out the advantages of LEDs while securing a sufficient amount of light by using a plurality of LEDs side by side.

On the other hand, the lens array 61 of the light source panel 62 corresponds to the 12 light emitting elements 601 on a one-to-one basis, and the lens group that forms an image of the light emitting area of each LED chip corresponds to the arrangement of the LED chips. Each of the light emitting elements 601 is formed by arranging 12 × 3 × 4 in dimension, and when viewed from the light emitting element 601 side, two of a biconvex first lens 611 and a planoconvex second lens 612 are provided. It has a lens group composed of a single sheet and is constructed by assembling them into a frame. That is, in the same manner as the arrangement of the light emitting elements 601 in the light source array 60, in the lens array 61, each of the 12 first lenses 611 and the 12 second lenses 612 is arranged in 3 rows and 4 columns. Thus, the two

lenses

611 and 612 are opposed to each of the twelve light emitting elements 601, and light from each light emitting element 601 is transmitted through the first lens 611 and the second lens 612, and the light source panel 62. The outside is injected. As described above, the optical head 6 is provided with the two light source panels 62. Among these, the light emitting element 601 of the light source panel 62a emits light having a central wavelength of 385 [nm], and the light emitting element 601 of the light source panel 62b emits light having a central wavelength of 365 [nm]. That is, the

light source panels

62a and 62b emit light having different center wavelengths.

Returning to FIG. 4, the description of the optical head 6 will be continued. Light emitted from each of the two light source panels 62 enters the dichroic mirror 63. The dichroic mirror 63 has one surface (transmission side) facing the light source panel 62a and the other surface (reflection side) facing the light source panel 62b. Light (12 lights) from each light emitting element 601 of the light source panel 62a is transmitted from one surface of the dichroic mirror 63 to the other surface, and light from each light emitting element 601 of the light source panel 62b (12 lights). Light) is reflected by the other surface of the dichroic mirror 63. In this way, light having different center wavelengths is synthesized by the dichroic mirror 63.

Incidentally, since the difference in the center wavelength of the light synthesized by the dichroic mirror 63 is about 20 [nm], the dichroic mirror 63 needs a spectral reflectance (spectral transmittance) characteristic having a relatively steep edge. Become. On the other hand, when the incident angle to the dichroic mirror 63 is 45 degrees or more, separation occurs in the optical characteristics of the PS polarization component, and a steep characteristic cannot be obtained. Therefore, the incident angle at which the light emitted from each of the

light source panels

62a and 62b enters the dichroic mirror 63 is set to be smaller than 40 degrees.

Twelve lights emitted from the dichroic mirror 63 enter the lens array 64. Similar to the lens array 61, the lens array 64 has a configuration in which twelve lenses 641 are arranged in a one-to-one correspondence with the twelve light emitting elements 601. That is, the lens array 64 is provided with twelve lenses 641 corresponding to the twelve lights emitted from the dichroic mirror 63 on a one-to-one basis. Further, an enlarged projection image of each corresponding light emitting element 601 is formed on each lens 641, and each light emitting element 601 and each corresponding lens 641 are optically conjugate, and each lens 641 is a field. It functions as a lens. Therefore, after the light emitted from the dichroic mirror 63 passes through the lens 641, the principal ray travels parallel to the optical axis direction. In this way, twelve light beams whose chief rays are parallel to the optical axis are emitted from the lens array 64.

The light emitted from the lens array 64 enters an optical system 65 composed of three

lenses

65a, 65b, and 65c. This optical system 65 is a telecentric optical system on both sides, and projects the image of the lens array 64 on the incident end 70a of the rod integrator 70 in a reduced scale and is emitted from the optical system 65 so that the principal ray is parallel to the optical axis. The incident light enters the rod integrator 70.

FIG. 8 is an optical path diagram of light incident on the rod integrator 70. In the figure, reference numeral Aoa indicates the optical axis direction of the optical head 6. As shown in the figure, the light emitted from the light source array 60 is imaged on the lens array 64 by the lens array 61. The imaging magnification at this time is set so that the image of the light emitting element 601 of the light source array 60 is larger than the outer shape of the lens 641 of the lens array 64. The shape of the lens array 64 is similar to the shape of the incident end 70 a of the rod integrator 70. The light transmitted through the lens array 64 is incident on the bilateral telecentric optical system 65 as parallel light whose principal ray is parallel to the optical axis direction Aoa. The light emitted from the optical system 65 is reduced and projected onto the incident end 70a of the rod integrator 70 as light whose principal ray is parallel to the optical axis direction Aoa.

Referring back to FIG. The rod integrator 70 equalizes the illuminance distribution of the light that has entered the incident end 70a and emits the light from the exit end 70b. As the rod integrator 70, various types such as a hollow rod type and a solid rod type can be used. In addition, the incident end 70a and the exit end 70b of the rod integrator 70 are similar to each other, but the respective dimensions do not have to be equal, and the rod integrator 70 formed in a tapered shape from the incident end 70a to 70b may be used. it can.

The light emitted from the exit end 70b of the rod integrator 70 enters the spatial light modulator 80 via the two lenses 66, the plane mirror 67a, and the concave mirror 67b. The exit end 70b of the rod integrator 70 and the spatial light modulator 80 are in an optically conjugate relationship. The spatial light modulator 80 is composed of a DMD in which a large number of micromirrors are arranged in a lattice pattern. The micro mirror of the spatial light modulator 80 is controlled by a control signal from the irradiation control unit 130 and takes a posture corresponding to either the on state or the off state. The micro mirror in the posture corresponding to the on state reflects the light from the rod integrator 70 toward the first projection lens 68. On the other hand, the microlens in the posture corresponding to the off state reflects light from the rod integrator 70 in a direction away from the first projection lens 68. Therefore, the light from the rod integrator 70 is reflected by the minute mirror in the on state of the spatial light modulator 80 and enters the first projection lens 68.

The first projection lens 68 and the second projection lens 69 function as a pair of projection lenses. After the magnification adjustment is performed by changing the distance between the first projection lens 68 and the second projection lens 69, the image of the spatial light modulator 80 is transferred to the surface of the substrate S. Is projected onto the irradiation region Re. Note that the minute mirror of the spatial light modulator 80 and the irradiation region Re on the surface of the substrate S are in an optically conjugate relationship. The optical head 6 shown in FIG. 4 includes an autofocus mechanism 95 that automatically adjusts the focus. The autofocus mechanism 95 includes an irradiation unit 96 that irradiates light to the irradiation region Re, and a light receiving unit 97 that receives reflected light from the irradiation region Re. Based on the light reception result of the light receiving unit 97, the second projection is performed. The focus is automatically adjusted by driving the lens 69 in the vertical direction.

FIG. 9 is a plan view schematically showing an image of the light emitting element 601 irradiated on the rod integrator 70. In the figure, a unit image IM is an image obtained by irradiating the rod integrator 70 with light from one light emitting element 601. As shown in the figure, corresponding to the arrangement of 12 light emitting elements 601 in the light source array 60 in 3 rows and 4 columns, in the

rod integrator

70, 12 unit images IM are arranged in 3 rows and 4 columns. As a result, the three unit images IM irradiated by the three light emitting elements 601 belonging to the same light emitting element row 601C are arranged in a straight line in the direction corresponding to the Y-axis direction of the substrate S to form the unit image row IMC. To do. That is, three unit images IM belonging to the same unit image row IMC are arranged in a direction corresponding to the Y-axis direction of the substrate S, which is the light scanning direction on the substrate S.

And in this embodiment, in order to adjust the illumination distribution of the light irradiated to the rod integrator 70 so that it may illustrate in FIG. 9, the illumination intensity of the unit image IM can be changed separately. Specifically, the irradiation control unit 130 individually controls the magnitude of the drive current Id for each light emitting element 601. Thereby, the luminance is individually controlled for each light emitting element 601, and the illuminance of the unit image IM is individually controlled. Thereby, the illuminance distribution in the irradiation region Re is adjusted. At this time, the irradiation control unit 130 controls the drive current Id of each light emitting element 601 based on the result of the optical sensor SC detecting the illuminance distribution of the irradiation region Re.

As described above, in this embodiment, the light source array 60 having a plurality of light emitting elements 601 that emit light with a luminance corresponding to the magnitude of the drive current Id is provided, and the rod integrator 70 is incident from the light source array 60. The illuminance distribution is made uniform with respect to the reflected light. In this embodiment, an irradiation control unit 130 that individually controls the magnitude of the drive signal Id for each light emitting element 601 is provided. The rod integrator 70 has a characteristic that when the illuminance is uneven in one direction of the incident end 70a of the rod integrator 70, a slight illuminance distribution is generated in the same direction also at the exit end 70b of the rod integrator 70. Therefore, the luminance is individually controlled for each light emitting element 601, and the illuminance distribution at the emission end 70b of the rod integrator 70 can be appropriately adjusted. As a result, in addition to the capability of the rod integrator 70, it is possible to improve the uniformity of the illuminance distribution at the exit end 70b of the rod integrator 70.

By the way, the pattern drawing apparatus 1 of this embodiment modulates the light emitted from the light source array 60 to the spatial light modulator 80 while moving the light source array 60 relative to the surface of the substrate S in the Y-axis direction. A pattern is drawn on the surface of S. At this time, if unevenness in the illuminance of the light applied to the surface of the substrate S occurs in the X-axis direction, a difference in exposure dose distribution appears on the surface of the substrate S, which is not preferable. On the other hand, in this embodiment, the emission end 70b of the rod integrator 70 is projected onto the spatial modulation element 80, and further projected onto the irradiation region Re by the first projection lens 68 and the second projection lens 69. Since the magnitudes of the drive signals Id of the four light emitting elements 601 that expose different areas in the axial direction are individually controlled for each light emitting element 601, the occurrence of uneven illuminance in the X axis direction is effectively suppressed. It is possible to do.

In this embodiment, an optical sensor SC that detects the illuminance distribution of the light emitted from the optical head 6 is provided. Then, the irradiation control unit 130 individually controls the magnitude of the drive signal Id for each light emitting element 601 according to the detection result of the optical sensor SC. In such a configuration, since the magnitude of the drive signal Id to each light emitting element 601 is controlled based on the result of detecting the illuminance distribution of the light emitted from the rod integrator 70, The uniformity of the illuminance distribution of irradiation light can be improved more reliably.

In particular, in this embodiment, the optical sensor SC detects the illuminance distribution of the light irradiated on the surface of the substrate S. Thereby, the uniformity of the illuminance distribution of the irradiation light on the surface of the substrate S can be further improved.

As described above, in this embodiment, the pattern drawing device 1 corresponds to the “pattern drawing device” of the present invention, the substrate S corresponds to the “drawing target” of the present invention, and the light emitting element 601 or the light emitting element array 601C is the book. The light source array 60 corresponds to the “light emitting unit” of the present invention, the rod integrator 70 corresponds to the “illuminance uniformizing element” of the present invention, and the spatial light modulator 80 corresponds to the present invention. The irradiation controller 130 corresponds to the “drive controller” of the present invention, the drive current Id corresponds to the “drive signal” of the present invention, and the Y-axis direction corresponds to the “spatial light modulator” of the present invention. It corresponds to the “first direction”, the X-axis direction corresponds to the “second direction” of the present invention, and the optical sensor SC corresponds to the “illuminance detector” of the present invention.

Note that the present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, the individual control of the drive current Id is performed for all the twelve light emitting elements 601 provided in the light source array 60. However, the application mode of the present invention is not limited to this. For example, the present invention can be applied in the following modes.

As described above, the three light-emitting elements 601 belonging to the same light-emitting element array 601C irradiate light while moving relative to the surface of the substrate S to perform overlapping exposure on the same region. Therefore, even if the illumination light of each of the light emitting elements 601 has uneven illuminance, the influence on the finally formed pattern is small. Therefore, it is possible to simplify the drive control by collectively controlling the magnitude of the drive current Id for the three light emitting elements 601 belonging to the same light emitting element row 601C. Incidentally, in such a modification, the light emitting element array 601C corresponds to the “light emitting portion” of the present invention.

In this modification, the same effect as described above can be obtained by individually controlling the magnitude of the drive current Id of the different light emitting element rows 601C. FIG. 10 is a block diagram illustrating a circuit of the irradiation control unit 130 that individually controls the light emitting elements 601. Three light emitting elements 601 belonging to the same light emitting element row 601C are connected in series, and their input terminals and output terminals are connected to the power supply 100 via the DC-DC converter 102. In addition, a current detector 103 is connected in series to the output side of these three light emitting elements 601, and the DC-DC converter 101 is connected to the DC-DC converter 101 in the irradiation controller 130 based on the detection result of the current detector 103. By changing the control voltage, the drive current Id given to these three light emitting elements 601 is controlled. A circuit having the same configuration is provided for each of the four light emitting element rows 601C. Therefore, it is possible to individually control the drive current Id applied to the light emitting element 601 for each light emitting element array 601C. Note that the four DC-DC converters 101 corresponding to the different light emitting element arrays 601C are connected to the power supply 100 via the AC-DC converter 102 and are supplied with power.

In the above embodiment, the drive signal Id to the light emitting element 601 is controlled based on the result of detecting the illuminance distribution. As a result, the integrated value (integrated light amount) of the light amount irradiated by exposure can be made uniform over substantially the entire area of the substrate S. At this time, an integrated light amount profile indicating the relationship between the drive signal Id and the integrated light amount may be measured in advance and stored in the irradiation control unit 130 or the like. Then, by controlling the drive signal Id based on this integrated light quantity profile, it is possible to make the integrated light quantity uniform over substantially the entire area of the substrate S and perform better pattern drawing.

In the above embodiment, the luminance of the light emitting element 601 is adjusted by controlling the magnitude of the drive current Id applied to the light emitting element 601. However, the luminance of the light emitting element 601 may be adjusted by controlling the drive voltage Vd applied to the light emitting element 601.

Further, although specific values of the drive current Id and the drive voltage Vd were not particularly mentioned, various modifications can be made to these values. Therefore, for example, the values of the drive current Id and the drive voltage Vd may be larger than the rated current and the rated voltage. Specifically, the values may be two or more times or three or more times the rated current and the rated voltage. Accordingly, the luminance of the light emitting element 601 can be significantly improved.

Further, in the above-described embodiment, the three unit images IM belonging to the same unit image row IMC are relatively moved in the same area on the surface of the substrate S, and the exposure is executed. However, the surface of the substrate S may be exposed without using such exposure method. Specifically, each time the substrate S moves by the length of the unit image row IMC in the X-axis direction, the twelve light emitting elements 601 are turned on, and the twelve unit image IM substrates shown in FIG. You may comprise so that irradiation to S may be performed.

Further, the arrangement of the plurality of light emitting elements 601 in the light source array 60 is not limited to the above. Therefore, the number of rows and columns in which a plurality of light emitting elements 601 are arranged can be changed as appropriate, and the interval between adjacent light emitting elements 601 can be changed as appropriate. Alternatively, a plurality of light emitting elements 601 may be arranged in a manner other than the matrix manner.

In the above embodiment, the substrate S and the optical head 6 are moved relative to each other by moving the substrate S in the Y-axis direction. However, the substrate S and the optical head 6 may be moved relative to each other by moving the optical head 6 in the Y-axis direction.

Further, the configuration of the optical sensor SC for detecting the light illuminance distribution is not limited to the above. The illuminance distribution may be detected by a two-dimensional image sensor installed separately. Further, the position where the optical sensor SC detects the illuminance distribution is not limited to the surface of the substrate S. Therefore, a part of the light incident on the spatial light modulator 80 may be branched, and the illuminance distribution may be detected by the optical sensor SC or a separately installed two-dimensional image sensor.

Further, the optical configuration of the optical head 6 is not limited to the above-described one, and addition, change, and deletion of each optical element constituting the optical head 6 can be appropriately executed. Therefore, the optical system 65 from the light source array 60 to the rod integrator 70 may be eliminated, and the rod integrator 70 may be disposed immediately after the lens array 64. Alternatively, all the optical configurations from the light source array 60 to the rod integrator 70 may be eliminated, and the rod integrator 70 may be disposed immediately after the light source array 60.

It is also possible to use an integrator other than the rod integrator 70. For example, a fly eye integrator configured with a fly eye lens may be used. In other words, the fly-eye integrator also functions as an integrator that makes the illuminance distribution uniform. At this time, a fly eye integrator may be disposed in the optical system 65 at a position where the principal ray of light intersects the optical axis. In addition, the shape of each lens constituting the fly eye integrator may be similar to the shape of the DMD 80.

In the above embodiment, two lights having different wavelengths are synthesized. However, it may be configured not to perform such light synthesis. Or you may comprise so that three light of a different wavelength may be synthesize | combined. In this case, a plurality of dichroic mirrors may be used, or a dichroic prism (cross prism, Philips type prism, Kester prism, etc.) may be used. Alternatively, these may be used in combination.

The type of the light emitting element 601 is not limited to the LED, and other various light sources can be used.

The present invention is used for a pattern drawing apparatus and a pattern drawing method in which light incident on a spatial light modulator via an illuminance uniformizing element such as a rod integrator 70 is modulated by the spatial light modulator and irradiated onto a substrate. Can do.

DESCRIPTION OF SYMBOLS 1 ... Pattern drawing apparatus 6 ... Optical head 60 ... Light source array 601 ... Light emitting element 601C ... Light emitting element row 62 ... Light source panel 62a ... Light source panel 62b ... Light source panel 63 ... Dichroic mirror 64 ... Lens array 65 ...

Optical system

67a, 67b ... Optical mirror 68 ... Zoom lens 69 ... Objective lens 70 ... Rod integrator 70a ... Incident end 70b ... Emission end 80 ... Spatial light modulator IM ... Unit image IMC ... Unit image sequence SC ... Optical sensor 100 ... Controller 110 ... Data processing unit 120 ... Scanning control unit 130 ... Irradiation control unit S ... Substrate

Claims

A light emitting unit having a plurality of light emitting units that emit light at a luminance according to the magnitude of the drive signal;
An illuminance uniformizing element that emits light incident from the light emitting unit after uniforming the illuminance distribution of the light, and
A spatial light modulator that modulates the light emitted from the illuminance equalizing element and irradiates the drawing target;
A pattern drawing apparatus comprising: a drive control unit that individually controls the magnitude of the drive signal for each light emitting unit.
2. The pattern is drawn on the drawing target by modulating the light emitted by the light emitting unit with the spatial light modulator while relatively moving the light emitting unit in the first direction with respect to the drawing target. In the described pattern drawing apparatus,
The plurality of light emitting units irradiate light to different positions in a second direction orthogonal to the first direction.
The light emitting unit is configured by a plurality of light emitting elements that each emit light at a luminance according to the magnitude of the drive signal, and each irradiates light at a position arranged linearly in the first direction,
The pattern drawing apparatus according to claim 2, wherein the drive control unit collectively controls the magnitude of the drive signal for the plurality of light emitting elements belonging to the same light emitting unit.
An illuminance detector for detecting an illuminance distribution of the light after being emitted from the illuminance equalizing element;
4. The pattern drawing device according to claim 1, wherein the drive control unit individually controls the magnitude of the drive signal for each light emitting unit according to a detection result of the illuminance detector. 5.
5. The pattern drawing apparatus according to claim 4, wherein the illuminance detector detects an illuminance distribution of the light irradiated on the drawing target.
The pattern drawing apparatus according to any one of claims 1 to 5, wherein the spatial light modulator is a DMD.
Individually controlling the magnitude of the drive signal to be given to a plurality of light emitting sections that emit light at a luminance corresponding to the magnitude of the drive signal;
Making the light from the plurality of light emitting parts incident on an illuminance uniformizing element that uniformizes and emits incident light; and
And a step of modulating the light emitted from the illuminance equalizing element with a spatial light modulator and irradiating the object to be drawn.