JP2010182934A - Drawing apparatus and drawing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the phase of each of beams made into multi-beam by a simple structure in a technique for making light from a light source into multi-beam using a plurality of micro-mirrors. <P>SOLUTION: The drawing apparatus 1 for drawing a pattern includes: a light splitting section 15 for splitting laser light by a reflection surface 150; spatial optical modulation devices 16, 17 equipped with a plurality of micro-mirrors; and a parallel flat plate 18 for inverting the phase by 1/4. Laser light emitted to the spatial optical modulation device 17 is subjected to conversion of the phase by 1/2 by the parallel flat plate 18 during forward and backward movement. The beam modulated by the spatial optical modulation device 16 and the beam modulated by the spatial optical modulation device 17 and having the phase inverted by the parallel flat plate 18 are composited in the reflection surface 150, and the substrate 9 is irradiated with the composited beam. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for controlling the phase of each beam that has been converted to a multibeam in a technique for converting light from a light source into a multibeam using a plurality of minute mirrors.

  In a technique (direct exposure) that directly draws precise fine patterns based on design data without using a photomask, a plurality of minute patterns arranged in an array form for high-precision and high-speed drawing. A technique is known in which light from a light source is converted into a multi-beam by a mirror for drawing. For example, Patent Document 1 discloses a drawing apparatus that draws a pattern using such a mirror device (spatial light modulation device).

  On the other hand, in the pattern exposure of semiconductors with advanced miniaturization, a technique for exposing a fine pattern exceeding the diffraction limit of a lens has been put into practical use by reversing the phase of light (180 degree shift) with a phase difference mask. (Phase shift method). As described above, a technique for performing exposure with super-resolution exceeding the diffraction limit has been developed in the field of semiconductor lithography, and a developing device (stepper) incorporating a function of shifting the phase of light into a pattern mask is practical. It has become.

  In direct exposure, a technique for controlling the phase of light that has been converted into a multi-beam by a spatial light modulation device has also been proposed. For example, a technique has been proposed in which a spring is provided on the back surface of each mirror of a spatial light modulation device, and the spring is expanded and contracted for each mirror so that the position of the reflecting surface of each mirror moves forward and backward with respect to the optical axis. Yes. As a result, the optical path length in the optical system of the light reflected by each mirror can be changed, so that the phase of the beam formed by each mirror is controlled. For example, if the difference between the optical path lengths of the two beams is controlled to be ½ of the wavelength of the beam, the phases of these two beams are inverted from each other.

JP 2003-332221 A

  However, when a pattern is drawn (exposed) using a phase shift mask as in the prior art, the phase shift mask is not easy to handle and is very expensive, and also requires time for production. there were. Further, the phase shift mask has to be manufactured for each pattern, and there is a problem that it cannot flexibly cope with a pattern change (design change).

  On the other hand, in the direct exposure, although the technique as described above has been proposed, there is a problem that the mirror device is a minute and complicated structure, and it is very difficult to design and manufacture the structure. That is, in order to incorporate the function of performing phase control in the spatial light modulation device, in addition to the function of deflecting individual micromirrors, a mechanism for moving the position of each micromirror in parallel with the light traveling direction is required. Become. In addition, the amount of movement of the micromirror at this time is also required to be exactly 1/4 with respect to the wavelength of light. Therefore, there was a problem that it has not been put into practical use at present.

  The present invention has been made in view of the above problems, and in a technique for converting light from a light source into a multi-beam using a spatial light modulation device, the phase of each beam converted into a multi-beam is controlled with a simple structure. The purpose is to do.

  In order to solve the above problems, the invention of claim 1 is a drawing apparatus for drawing a pattern by a plurality of beams, and a light source for irradiating light, light emitted from the light source as first light and second light. Light dividing means for dividing the light into light, a first spatial light modulation device for modulating the first light divided by the light dividing means into a plurality of first beams, and the second light divided by the light dividing means. A second spatial light modulation device that modulates a plurality of second beams; phase conversion means that sets the phase of the first beam and the phase of the second beam different from each other; and the first beam that has the phases different from each other. And beam combining means for combining the second beam and the second beam.

  The invention of claim 2 is the drawing apparatus according to the invention of claim 1, wherein the phase conversion means is an optical element that satisfies nλ ± (1 / m) λ (where n and m are integers, 1 / M is a predetermined phase difference).

  According to a third aspect of the present invention, there is provided a drawing apparatus for drawing a pattern with a plurality of beams, a light source for irradiating light, and light for dividing light emitted from the light source into first light and second light. A splitting means; a first spatial light modulation device that modulates the first light split by the light splitting means into a plurality of first beams; and a second light split by the light splitting means into a plurality of second beams. A second spatial light modulation device that modulates the first spatial light modulation device and the second spatial light modulation device such that the phase of the first beam and the phase of the second beam are different from each other. Is arranged, and the first beam and the second beam having different phases are combined.

  According to a fourth aspect of the present invention, there is provided the drawing apparatus according to any one of the first to third aspects, further comprising a light amount control means for controlling the light amounts of the plurality of beams.

  Further, the invention of claim 5 is a drawing method for drawing a pattern with a plurality of beams, wherein (a) a step of irradiating light from a light source, and (b) light emitted from the light source as first light. Splitting into second light, (c) modulating the first light into a plurality of first beams with a first spatial light modulation device, and (d) second spatial light modulation device with the second light. And (e) a step of setting the phase of the first beam and the phase of the second beam different from each other.

  The invention of claim 6 is the drawing method according to the invention of claim 5, wherein the step (e) causes the phase of the first beam and the phase of the second beam to be mutually changed by the phase conversion means. It is a process which makes it a different phase.

  Further, the invention of claim 7 is the drawing method according to the invention of claim 5, wherein the step (e) includes the phase of the first beam according to the optical path length difference between the first beam and the second beam. And the phase of the second beam are different from each other.

  The invention according to claim 8 is the drawing method according to any one of claims 5 to 7, further comprising the step of (f) controlling the light quantity of the plurality of beams.

  According to the first aspect of the present invention, a light splitting unit that splits the light emitted from the light source into the first light and the second light, and the first light split by the light splitting unit is modulated into a plurality of first beams. The first spatial light modulation device, the second spatial light modulation device that modulates the second light split by the light splitting means into a plurality of second beams, and the phase of the first beam and the phase of the second beam Providing a special structure to the spatial light modulation device in direct digital exposure by providing phase conversion means for different phases and beam synthesis means for synthesizing the first beam and the second beam having different phases The phase can be controlled.

  In the invention according to claim 2, the phase conversion means is an optical element satisfying nλ ± (1 / m) λ (where n and m are integers and 1 / m is a predetermined phase difference), The invention of claim 1 can be easily realized.

  According to a third aspect of the present invention, there is provided a light dividing means for dividing the light emitted from the light source into the first light and the second light, and the first light divided by the light dividing means is modulated into a plurality of first beams. And a second spatial light modulation device that modulates the second light divided by the light dividing means into a plurality of second beams, the phase of the first beam and the phase of the second beam Of the first spatial light modulation device and the second spatial light modulation device are determined such that the first and second spatial light modulation devices have different phases, and by combining the first beam and the second beam having different phases, direct In digital exposure, the phase can be controlled without providing a special structure in the spatial light modulation device.

  In the inventions according to claims 4 and 8, the super-resolution exceeding the diffraction limit can be achieved by controlling the light quantity of a plurality of beams and combining phase control and light quantity control without creating a phase shift mask. realizable.

  The invention according to any one of claims 5 to 8 includes a step of irradiating light from a light source, a step of dividing light emitted from the light source into first light and second light, and first spatial light modulation. The step of modulating the plurality of first beams by the device, the step of modulating the second light into the plurality of second beams by the second spatial light modulation device, and the phases of the first beam and the second beam are different from each other. In the direct digital exposure, the phase can be controlled without providing a special structure in the spatial light modulation device.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.

<1. First Embodiment>
FIG. 1 is a diagram illustrating a drawing apparatus 1 according to the first embodiment. In FIG. 1, for convenience of illustration and description, the Z-axis direction is defined as the vertical direction, and the XY plane is defined as the horizontal plane. However, these directions are defined for convenience in order to grasp the positional relationship, and do not limit each direction described below. The same applies to the following drawings.

  The drawing apparatus 1 includes a movable stage 10, a drawing head 11, and a control unit 2, and is configured as an apparatus that draws a fine pattern (image) on a substrate 9 supported by the movable stage 10.

  The object on which the pattern is drawn is not limited to the substrate 9 and may be paper or a three-dimensional object. Further, the drawing apparatus according to the present invention is not limited to the one in which an image to be drawn can be visually recognized, and is a concept including an exposure apparatus, for example. In addition, an image drawn by one drawing operation of the drawing apparatus 1 is formed of n pixels (n is an integer of 1 or more). In the following description, the configuration corresponding to the nth pixel is described as “ The subscript “n” shall be attached.

  The upper surface of the movable stage 10 is processed into a horizontal plane and has a function of holding the substrate 9 in a horizontal posture. The movable stage 10 performs suction from a suction port (not shown), thereby sucking the back surface of the placed substrate 9 and holding the substrate 9 in a predetermined position.

  The movable stage 10 can move linearly in the X-axis direction and the Y-axis direction in accordance with a control signal from the control unit 2. Although not described in detail, the movable stage 10 includes a main scanning drive mechanism that moves the substrate 9 in the Y-axis direction and a sub-scanning drive mechanism that moves the substrate 9 in the X-axis direction. As such a mechanism, for example, a linear motion mechanism using a linear motor can be employed.

  Thereby, the drawing apparatus 1 can irradiate the light irradiated from the drawing head 11 to an arbitrary position on the surface of the substrate 9. As described above, the laser light emitted from the drawing apparatus 1 is imaged with the surface of the substrate 9 as the image plane.

  The drawing head 11 includes a laser oscillator 13 as a light source for irradiating laser light, an illumination optical system 14 that guides the laser light emitted from the laser oscillator 13 in a predetermined direction, and laser light guided by the illumination optical system 14. A light splitting unit 15 for splitting is provided. Further, the drawing head 11 forms an image on the substrate 9 with spatial light modulation devices 16 and 17 that modulate incident laser light, a parallel plane plate 18 that converts the phase of the passing laser light, and the modulated laser light. An imaging optical system 19 is provided.

  The laser oscillator 13 intermittently turns on a laser beam having a predetermined pulse width according to a reset signal transmitted from the control unit 2 at a cycle T (becomes a pulse laser). Thereby, the laser oscillator 13 in this Embodiment functions as a light source which irradiates a laser beam with the period T (predetermined period). Note that the laser light emitted by the laser oscillator 13 in this embodiment is plane wave coherent light.

  In general, when the exposure interval is short, the movement of the movable stage 10 must be completed during the exposure interval. Therefore, it is necessary to move the movable stage 10 at a relatively high speed. On the other hand, if the exposure interval is long, the allowable time for completing the movement of the movable stage 10 becomes long, so that the movable stage 10 can be moved at a low speed. However, if the movable stage 10 is moved at a low speed, the time required to complete the exposure of the entire pattern becomes longer and the processing itself is delayed.

  Since the laser oscillator 13 in the present embodiment irradiates laser light at a constant exposure time (pulse width) and a constant exposure interval (period T) as described above, the moving speed of the movable stage 10 may be constant. . Therefore, the drive control becomes easy and it is possible to prevent the movement of the movable stage 10 from becoming unstable due to the speed change.

  In the drawing apparatus 1 in the present embodiment, an excimer laser is employed as the laser oscillator 13 that irradiates a pulse laser. The pulse width is about 10 [nsec] to several tens [nsec]. However, the laser beam used in the drawing apparatus 1 is not limited to such a laser beam.

  The illumination optical system 14 includes a mirror 140 and a lens 141. Laser light emitted from the laser oscillator 13 and incident on the illumination optical system 14 is guided to the light splitting unit 15 by the mirror 140 and the lens 141.

  As described above, the illumination optical system 14 has a function of appropriately adjusting the optical path of the laser light emitted from the laser oscillator 13 and guiding it to the light splitting unit 15. Note that the configuration of the illumination optical system 14 is not limited to that shown in the present embodiment, and another optical element such as another lens or mirror may be appropriately disposed on the optical path of the laser light.

  The light splitting unit 15 on which the laser light guided by the illumination optical system 14 is incident is configured as a prism having a reflection surface 150 constituting a so-called half mirror inside. The laser light that has entered the light splitting unit 15 passes through the reflecting surface 150 in the prism and travels straight, and is reflected by the reflecting surface 150 in the prism and a component (first laser light component) that travels toward the spatial light modulation device 16. It is divided into a component (second laser beam component) directed to the plane parallel plate 18.

  The spatial light modulation devices 16 and 17 are arranged at positions where the optical axis distances from the light dividing section 15 are equal to each other, and have a structure in which a large number of minute mirrors are arranged in a lattice pattern on a silicon substrate. . In the drawing apparatus 1 according to the present embodiment, micromirror devices are employed as such spatial light modulation devices 16 and 17. Hereinafter, the micromirrors included in the spatial light modulation devices 16 and 17 are referred to as “micromirrors” and are distinguished from other mirrors (for example, the mirror 140).

  Each micromirror of the spatial light modulation devices 16 and 17 corresponds to each pixel of an image drawn by the drawing apparatus 1. That is, each of the spatial light modulation devices 16 and 17 has n micromirrors. In addition, each micromirror is designed so that the reflection surface can be tilted in accordance with a control signal transmitted from the control unit 2, thereby controlling the reflection angle of the laser beam by each micromirror. ing.

  The first laser beam split by the light splitting unit 15 is incident on the spatial light modulation device 16. Then, the first laser light incident on the spatial light modulation device 16 is reflected by each micromirror of the spatial light modulation device 16 to be modulated into a plurality of first beams. Then, according to the reflection angle of each micromirror at this time, a part of the plurality of first beams is again directed to the light dividing unit 15 and reflected by the reflecting surface 150 of the light dividing unit 15 to form an image. The light enters the optical system 19.

  The second laser light split by the light splitting unit 15 enters the spatial light modulation device 17 after passing through the plane parallel plate 18. Then, the second laser light incident on the spatial light modulation device 17 is reflected by each micromirror of the spatial light modulation device 17 and thereby modulated into a plurality of second beams. And according to the reflection angle of each micromirror at this time, some of the formed second beams are directed toward the plane parallel plate 18 again.

  The plane-parallel plate 18 is an optical element having a function of shifting the phase of light with respect to the difference in optical path length before and after the optical path on which it is provided by a ¼ wavelength. Specifically, the optical element satisfies the general formula, nλ ± (1 / m) λ (where n and m are integers and 1 / m is a predetermined phase difference). The phase of the second laser light incident on the plane-parallel plate 18 from the light splitting unit 15 is incident on the spatial light modulation device 17 after being converted in phase by the ¼ wavelength by the plane-parallel plate 18. Further, the plurality of second beams reflected and modulated by the spatial light modulation device 17 are incident on the parallel plane plate 18 again, and the phase is again converted by ¼ wavelength.

  As a result, the phase of the second beam is light that differs in phase by ½ wavelength compared to the phase of the first beam. That is, the second beam formed by the spatial light modulation device 17 is light obtained by inverting the phase of the first beam formed by the spatial light modulation device 16.

  In the spatial light modulation device 16 and the spatial light modulation device 17, the optical system is adjusted so that the light from the micromirror corresponding to the same pixel is at the same position on the reflection surface 150 of the light splitting unit 15. ing.

  Although not shown in detail, the control unit 2 is mainly composed of a CPU that calculates data, a memory that stores data such as pixel data 20 and characteristic data, and a circuit (drive circuit) that generates various signals. Yes.

  The pixel data 20 is data created according to the pattern to be drawn, and is created by an external device and stored in the control unit 2. In the pixel data 20 in the present embodiment, a pixel having a pixel value of “positive” indicates a pixel drawn by a “positive phase” beam. On the other hand, a pixel whose pixel value is “negative” indicates a pixel drawn by a beam of “reverse phase (phase obtained by shifting the phase of a positive phase beam by 180 °)”. Further, the absolute value of the pixel value indicates the light amount of the beam for drawing the pixel.

  The control unit 2 has a function of controlling each configuration of the drawing apparatus 1. For example, the control unit 2 controls the horizontal position of the movable stage 10 or transmits a reset signal to the laser oscillator 13 to irradiate laser light at a period T. Let

  Further, the control unit 2 controls the reflection angle of each micromirror of the spatial light modulation device 16 based on the pixel data 20, so that only the beam corresponding to the pixel to be drawn with the positive phase beam is transmitted to the light dividing unit 15. While reflecting in the direction (−Z direction), the beam is reflected in the direction in which the beam is turned off for the other pixels.

  Further, the control unit 2 controls the reflection angle of each micromirror of the spatial light modulation device 17 based on the pixel data 20 so that only the beam corresponding to the pixel to be drawn with the beam having the opposite phase is displayed on the parallel plane plate 18. While reflecting in the direction (+ Y direction), the beam is reflected in the direction in which the beam is turned off for the other pixels.

  Although detailed description is omitted, in the drawing apparatus 1 according to the present embodiment, the control unit 2 reflects each micromirror of the spatial light modulation devices 16 and 17 according to the absolute value of the pixel value in the pixel data 20. By controlling the angle, the incident position of each beam on the aperture 190 is controlled, and thereby the light quantity of each beam is controlled. That is, the control unit 2, the spatial light modulation devices 16 and 17, and the aperture 190 implement the light amount control means in the present invention. However, the method of controlling the light quantity is not limited to this, and various conventionally proposed methods can be appropriately employed.

  The imaging optical system 19 includes an aperture 190, a mirror 191 and an imaging lens 192.

  The beam emitted from the aperture 190 is emitted toward the mirror 191. The beam emitted toward the mirror 191 is reflected by the mirror 191 and applied to the surface of the substrate 9 serving as an image plane via the imaging lens 192. Thereby, each beam is irradiated to the position of the pixel corresponding to each beam, and a desired pixel is drawn.

  The above is the description of the configuration and function of the drawing apparatus 1. Next, the principle of realizing a resolution exceeding the diffraction limit of the optical system in such a drawing apparatus 1 will be described.

  First, a case where there is no function for controlling the phase of the beam (when only a beam having a positive phase can be irradiated) will be described.

  FIG. 2 is a diagram illustrating an arrangement example of pixels when one pixel is drawn with one beam having a positive phase. FIG. 2 shows an example in which the central pixel P3 among the seven pixels P0 to P6 arranged one-dimensionally is drawn. Therefore, in this example, only the beam formed by the micromirror corresponding to the pixel P3 is irradiated. In addition, as for the size of each pixel P0 to P6, the vertical and horizontal length sizes are all set to the beam pitch BP.

  FIG. 3 is a diagram illustrating an ideal beam amplitude distribution for drawing the pattern illustrated in FIG. 2. According to this, it can be seen that it is preferable to irradiate the beam only on the position corresponding to the pixel P3.

  FIG. 4 is a diagram showing the light intensity distribution on the imaging plane when one beam is irradiated onto the pixel P3.

  Comparing FIG. 4 with FIG. 3, it can be seen that the light intensity distribution is wider than the beam pitch, and the region irradiated with the beam is larger than the size of the pixel P3. This spread is constant by the optical system of the apparatus due to the diffraction limit determined by the wavelength of the beam and the numerical aperture of the lens of the optical system, and cannot be narrowed (squeezed) any further.

FIG. 5 is a diagram showing the distribution of light energy in the example shown in FIG. The threshold value V shown in FIG. 5 is a value indicating the sensitivity of the photosensitive material. As shown in FIG. 5, in the case of drawing without inverting the phase, the minimum size of the beam drawing area is VP ₀ .

  Next, a case where it is possible to irradiate a beam whose phase is inverted for each pixel will be described.

  FIG. 6 is a diagram illustrating an example of pixel arrangement when one pixel is drawn while irradiating a plurality of pixels with a beam whose phase is inverted. FIG. 6 shows an example of drawing the central pixel P3 among the seven pixels P0 to P6 arranged one-dimensionally as in FIG. However, the pixels P1 and P5 are irradiated with a beam whose phase is inverted. That is, a positive pixel value is stored in the pixel P3, and a negative pixel value is stored in the pixels P1 and P5.

  FIG. 7 is a diagram showing the amplitude of the beam given to the pixels P1, P3, and P5 when the pattern shown in FIG. 6 is drawn. In FIG. 7, the amplitude of the positive-phase beam is indicated by a positive value, and the amplitude of the anti-phase beam is indicated by a negative value. In the example shown here, the amplitude of the antiphase beam is smaller than the amplitude of the positive phase beam.

  FIG. 8 is a diagram showing the light intensity distribution on the imaging plane for each beam in the example shown in FIG. Since the spread of the intensity distribution of each beam is determined by the diffraction limit of the optical system as described above, it is substantially constant regardless of the amplitude of each beam.

  FIG. 9 is a diagram showing the light intensity distribution on the imaging plane in the example shown in FIG. In a region where a region irradiated with a positive phase beam and a region irradiated with a reverse phase beam overlap, the beam intensities are subtracted from each other.

FIG. 10 is a diagram showing the distribution of light energy in the example shown in FIG. By irradiating the beam from the micromirrors corresponding to the three pixels P1, P3, and P5, the region irradiated with the beam is expanded compared to the example shown in FIG. However, the components in the peripheral portion are suppressed as compared with the case shown in FIG. 5, and the size (peak in the peripheral portion) is made lower than the sensitivity of the photosensitive material (by selecting such a photosensitive material). The minimum size of the beam drawing area is VP ₁ . The comparison between VP ₁ of VP ₀ and 10 in FIG. 5, is less clearly towards the size of VP _1. That is, it can be seen that the resolution exceeding the diffraction limit can be realized by irradiating the beam having the opposite phase obtained by inverting the phase of the beam having the positive phase.

  As described above, the drawing apparatus 1 controls the phase and the amount of light for each pixel (each micromirror), thereby realizing high resolution exceeding the diffraction limit without using an expensive phase shift mask.

  It should be noted that the principle shown here is a simplified example, and there are various pixels and light amounts to be irradiated with the positive phase or reverse phase beam depending on the pattern shape to be drawn, the profile (intensity distribution) of the beam to be used, etc. Change. Pixel data in the present embodiment is created by executing resolution improvement processing (for example, Optical Proximity Correction) on bitmap data generated from CAD data. As described above, in the pixel data in the present embodiment, the absolute value of the pixel value indicates the amount of light, and the sign indicates the phase (“positive sign” indicates the positive phase, and “negative sign” indicates the reverse phase). Further, the resolution improvement process may be executed by an external device or may be executed by the control unit 2.

  Next, a drawing method for drawing a pattern using the drawing apparatus 1 will be described.

  FIG. 11 is a flowchart showing a drawing method according to the present invention. FIG. 11 shows a flow of one drawing. Therefore, the process shown in FIG. 11 is repeated a plurality of times for drawing an actual pattern. Further, it is assumed that the substrate 9 is placed on the movable stage 10 and the relative position of the movable stage 10 (substrate 9) with respect to the drawing head 11 is determined before the process of step S11 shown in FIG. 11 is started. .

  First, the control unit 2 controls the reflection angle of the micromirror corresponding to each pixel according to the pixel data 20 (step S11). Thereby, each micromirror of the spatial light modulation devices 16 and 17 becomes a reflection angle according to each pixel.

  Next, the control unit 2 transmits a reset signal to the laser oscillator 13 so that the laser oscillator 13 emits laser light (step S12). The laser light irradiated in step S12 is guided to the illumination optical system 14, enters the light splitting unit 15, and the first laser light directed to the spatial light modulation device 16 and the spatial light modulation device 17 (parallel plane plate 18). (Step S13).

  The first laser light incident on the spatial light modulation device 16 is reflected by each micromirror of the spatial light modulation device 16 and modulated into a plurality of first beams (step S14).

  On the other hand, the second laser light incident on the plane-parallel plate 18 is subjected to ¼ phase conversion by the plane-parallel plate 18 (step S15) and then enters the spatial light modulation device 17. Then, the light is reflected by each micromirror of the spatial light modulation device 17 and modulated into a plurality of second beams (step S16). Further, among the plurality of second beams, a beam corresponding to a pixel to be drawn with an antiphase beam is incident on the parallel plane plate 18 again, and is subjected to ¼ phase conversion by the parallel plane plate 18 (step S17).

  The first beam from the spatial light modulation device 16 and the second beam from the plane parallel plate 18 (spatial light modulation device 17) are combined in the light splitting unit 15 (step S18) and enter the imaging optical system 19. .

  The light quantity of the plurality of beams (first beam and second beam) from the light splitting unit 15 is controlled by the aperture 190 of the imaging optical system 19 in accordance with the reflection angle control executed in step S11 (step S19). ). More specifically, since the incident position on the aperture 190 is slightly different depending on the difference in reflection angle, for example, in the example shown in FIG. To do.

  The beam that has passed through the aperture 190 is guided to the mirror 191 and the imaging lens 192 to be irradiated on the surface of the substrate 9. Thereby, a pixel (pattern) is drawn at a predetermined position on the substrate 9 (step S20).

  As described above, the drawing apparatus 1 according to the first embodiment includes the light splitting unit 15 that splits the light emitted from the laser oscillator 13 into the first laser light and the second laser light, and the light splitting unit 15. A spatial light modulation device 16 that modulates the divided first laser light into a plurality of first beams; and a spatial light modulation device 17 that modulates the second laser light divided by the light dividing unit 15 into a plurality of second beams; In the direct digital exposure, a parallel plane plate 18 having a phase different from the phase of the first beam and the phase of the second beam is combined, and the first beam and the second beam having different phases are combined. The phase can be controlled without providing a special structure in the spatial light modulation devices 16 and 17.

  In addition, by controlling the light amounts of a plurality of beams, it is possible to realize super-resolution exceeding the diffraction limit without creating a phase shift mask by combining phase control and light amount control.

  The plane parallel plate 18 may be provided on the spatial light modulation device 16 side.

<2. Second Embodiment>
In the first embodiment, an example has been described in which the parallel plane plate 18 forms an antiphase beam whose phase is inverted with respect to the positive phase beam. However, the method of converting the phase is not limited to this.

  FIG. 12 is a schematic diagram showing the light splitting unit 15 and the spatial light modulation devices 16 and 17 of the drawing apparatus 1a according to the second embodiment.

  The drawing apparatus 1a does not have a configuration corresponding to the plane-parallel plate 18 in the drawing apparatus 1, but the optical axis distance between the light splitting unit 15 and the spatial light modulation device 16 is “L1”. The optical axis distance between the light splitting unit 15 and the spatial light modulation device 17 is “L2”. Then, assuming that the wavelength of the laser light emitted from the laser oscillator 13 is “λ”, the optical axis distances L1 and L2 are determined so as to satisfy Expression 1 using the integer i.

  L2−L1 = (i ± 1/4) × λ Equation 1

  As described above, the drawing apparatus 1a according to the second embodiment has the spatial light modulation device 16 and the spatial space so that the phase of the first beam and the phase of the second beam are different from each other (inverted phase). The arrangement of the light modulation device 17 has been determined. As a result, the phase of the first beam and the phase of the second beam can be made different from each other due to the optical path length difference between the first beam and the second beam, which is the same as the drawing apparatus 1 in the first embodiment. The effect of can be obtained.

<3. Modification>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made.

  For example, although the light splitting unit 15 has been described as a prism having the reflecting surface 150 in the above embodiment, the light splitting unit 15 may be a simple half mirror.

  Further, instead of the aperture 190, an optical element whose amount of light changes depending on the position of light passing therethrough, such as a continuous density variable filter, may be used.

  Further, as a configuration for controlling the amount of light, instead of using a micromirror device as a spatial light modulation device as in the above-described embodiment, a diffraction grating type spatial light modulation element such as GLV (Grating Light Valve) or magnetic A configuration using an optical spatial light modulator may be adopted.

  Moreover, each process shown in the said embodiment is an illustration to the last, and if the same effect is acquired, the content and order of each process may be changed suitably.

It is a figure which shows the drawing apparatus in 1st Embodiment. It is a figure which shows the example of an arrangement | sequence of a pixel at the time of drawing one pixel with one beam of a positive phase. It is a figure which shows distribution of the amplitude of an ideal beam for drawing the pattern illustrated in FIG. It is a figure which shows intensity distribution of the light in the image plane at the time of irradiating one beam to the pixel P3. In the example shown in FIG. 4, it is a figure which shows distribution of the energy of light. It is a figure which shows the example of an arrangement | sequence of a pixel at the time of drawing one pixel, irradiating the beam which reversed the phase to several pixels. It is a figure which shows the amplitude of the beam given to the pixels P1, P3, and P5 when drawing the pattern shown in FIG. In the example shown in FIG. 7, it is a figure which shows the intensity distribution of the light in an image plane for every beam. In the example shown in FIG. 7, it is a figure which shows intensity distribution of the light in an image plane. In the example shown in FIG. 9, it is a figure which shows distribution of the energy of light. 3 is a flowchart showing a drawing method according to the present invention. It is the schematic which shows the light division part of the drawing apparatus in 2nd Embodiment, and a spatial light modulation device.

DESCRIPTION OF SYMBOLS 1,1a Drawing apparatus 10 Movable stage 11 Drawing head 13 Laser oscillator 14 Illumination optical system 15 Light dividing part 150 Reflecting surface 16, 17 Spatial light modulation device 18 Parallel plane plate 19 Imaging optical system 190 Aperture 2 Control part 20 Pixel data 9 substrate

Claims (8)

A drawing apparatus for drawing a pattern by a plurality of beams,
A light source that emits light;
A light splitting means for splitting light emitted from the light source into first light and second light;
A first spatial light modulation device that modulates the first light split by the light splitting means into a plurality of first beams;
A second spatial light modulation device that modulates the second light split by the light splitting means into a plurality of second beams;
Phase conversion means for setting the phase of the first beam and the phase of the second beam different from each other;
Beam combining means for combining the first beam and the second beam having different phases;
A drawing apparatus comprising: The drawing apparatus according to claim 1,
The drawing apparatus, wherein the phase conversion means is an optical element satisfying nλ ± (1 / m) λ (where n and m are integers and 1 / m is a predetermined phase difference). A drawing apparatus for drawing a pattern by a plurality of beams,
A light source that emits light;
A light splitting means for splitting light emitted from the light source into first light and second light;
A first spatial light modulation device that modulates the first light split by the light splitting means into a plurality of first beams;
A second spatial light modulation device that modulates the second light split by the light splitting means into a plurality of second beams;
With
The arrangement of the first spatial light modulation device and the second spatial light modulation device is determined so that the phase of the first beam and the phase of the second beam are different from each other, and the phases different from each other are determined. A drawing apparatus characterized by combining a first beam and a second beam. The drawing apparatus according to any one of claims 1 to 3,
A drawing apparatus, further comprising light amount control means for controlling light amounts of the plurality of beams. A drawing method for drawing a pattern by a plurality of beams,
(a) irradiating light from a light source;
(b) dividing the light emitted from the light source into first light and second light;
(c) modulating the first light into a plurality of first beams by a first spatial light modulation device;
(d) modulating the second light into a plurality of second beams by a second spatial light modulation device;
(e) the phase of the first beam and the phase of the second beam are different from each other;
A drawing method characterized by comprising: The drawing method according to claim 5, wherein
The drawing method, wherein the step (e) is a step of setting the phase of the first beam and the phase of the second beam different from each other by phase conversion means. The drawing method according to claim 5, wherein
The step (e) is a step of setting the phase of the first beam and the phase of the second beam different from each other according to the optical path length difference between the first beam and the second beam. Drawing method. A drawing method according to any one of claims 5 to 7,
(f) The drawing method further comprising the step of controlling the light quantity of the plurality of beams.

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