JPWO2018066338A1 - Pattern drawing device - Google Patents

Abstract

The pattern drawing device (EX) sequentially passes the beam from the light source device (LS) in order to selectively supply the beam from the light source device (LS) to any one of the plurality of drawing units (Un). And a beam switching unit having a plurality of optical members for selection (OSn) for directing the beam to the drawing unit (Un) by electrical control, and a specific drawing unit of the plurality of drawing units (Un) ( When adjusting the intensity of the beam projected from (Un) to the substrate (P), the beam projected onto the substrate (P) within the adjustable range of the beam intensity adjusting unit corresponding to the specific drawing unit (Un). The intensity is adjusted, and the intensity of the beam projected from each of the other drawing units (Un) other than the specific drawing unit (Un) onto the substrate (P) is changed from the specific drawing unit (Un) to the substrate (P). Throw As it aligns the intensity of the beam, a control unit for controlling each corresponding beam intensity adjusting unit of the other drawing units (Un) and (250), the.

Description

  The present invention relates to a pattern drawing apparatus that draws a predetermined pattern on a substrate by scanning a beam spot on the substrate as an irradiation object.

  Conventionally, a spot light of a laser beam is projected onto an object to be irradiated (processing object), and the spot light is main-scanned in a one-dimensional direction by a scanning mirror (polygon mirror), and the object to be irradiated is set in the main scanning line direction. In order to form a desired pattern or image (characters, figures, etc.) on the irradiated object by moving in the orthogonal sub-scanning direction, for example, an image forming apparatus (drawing apparatus) as disclosed in Japanese Patent Application Laid-Open No. 2008-195019 )It has been known.

  Japanese Patent Application Laid-Open No. 2008-195019 discloses that a plurality of scanning areas (sharing areas) set on a photosensitive material that is a photographic printing paper are each scanned by sharing with an exposure beam from a laser exposure unit. When forming (drawing) an image on a laser beam, the relationship between the predetermined change in the temperature of the laser exposure unit and the change in the intensity of the exposure beam so that the exposure amount due to the exposure beam does not fluctuate due to the temperature change of the plurality of laser exposure units On the basis of the above, it is disclosed that the intensity of the exposure beam from the laser exposure unit is adjusted to suppress the density unevenness at the joints of the scanning regions that each laser exposure unit is responsible for. In the image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 2008-195019, three laser light sources that output laser light in red, green, and blue wavelength bands corresponding to the three primary colors of light to each of the three laser exposure units. And three acousto-optic modulators (AOM) for individually modulating the intensity of red laser light, green laser light, and blue laser light from each of the three laser light sources according to image data, and each of the three AOMs A half mirror that superimposes the three laser beams into one, a rotating polygon mirror that scans one superimposed laser beam, and a laser beam scanned by the polygon mirror at a constant speed on the photosensitive material Fθ lens or the like is provided.

  In Japanese Patent Application Laid-Open No. 2008-195019, the temperature of the laser light source and the AOM is controlled by the temperature control unit. However, the exposure amount changes when the temperature changes by 0.1 ° C. or more with respect to the set temperature. The modulation level of the AOM that modulates the laser light according to the image data is corrected according to the temperature change measured by the temperature sensor. That is, in Japanese Patent Application Laid-Open No. 2008-195019, even if there is a delay in temperature control or an overshoot phenomenon that may occur while the temperature inside the housing slightly deviates from the set temperature and returns to the original temperature, Variations in the exposure amount at the laser exposure unit are corrected by adjusting the modulation level of the AOM, thereby suppressing density unevenness due to discontinuous exposure amount differences at the boundaries of the shared areas on the photosensitive material.

  A first aspect of the present invention is a pattern drawing apparatus that draws a pattern on the substrate by a plurality of drawing units that draw a pattern by scanning a beam from a light source device on the substrate by a scanning member, In order to selectively supply a beam from the light source device to any one of the plurality of drawing units, the beam from the light source device is arranged to pass in order, and the beam is drawn by electrical control. Corresponding to the specific drawing unit when adjusting the intensity of the beam projected to the substrate from a specific drawing unit of the plurality of drawing units, and a beam switching unit having a plurality of selection optical members directed to the unit The beam intensity projected onto the substrate is adjusted within the adjustable range of the beam intensity adjusting unit, and other drawing units other than the specific drawing unit are adjusted. The beam intensity adjusting unit corresponding to each of the other drawing units is arranged so that the intensity of the beam projected on the substrate from each of the other drawing units is aligned with the intensity of the beam projected on the substrate from the specific drawing unit. A control unit for controlling.

  A second aspect of the present invention is a pattern drawing apparatus that draws a pattern on the substrate by a plurality of drawing units that draw a pattern by scanning a beam from a light source device on the substrate by a scanning member, In order to selectively supply a beam from the light source device to any one of the plurality of drawing units, the beam from the light source device is arranged to pass in order, and the beam is drawn by electrical control. A beam switching unit having a plurality of selection optical members directed to the unit, and a plurality of beams provided corresponding to each of the plurality of drawing units and capable of adjusting the intensity of the beam projected on the substrate within a predetermined range Of the plurality of selection optical members, an intensity adjustment unit is selected by the selection optical member that finally enters the beam from the light source device, and the drawing unit is selected. The plurality of beam intensity adjusting units so as to align the intensity of the beam projected from each of the plurality of drawing units to the substrate based on an adjustable range of the intensity of the beam projected onto the substrate via And a control unit for controlling.

  A third aspect of the present invention is a pattern drawing apparatus that draws a pattern on the substrate by a plurality of drawing units that draw a pattern by scanning a beam from the light source device on the substrate with a scanning member, the light source An electrooptic selection optical member for deflecting a beam from the apparatus toward the drawing unit is provided corresponding to each of the plurality of drawing units, and a plurality of the beams from the light source device are used for the selection. A beam switching unit having a plurality of optical elements for guiding light so as to pass through each of the optical members in order, and selectively supplying a beam from the light source device to one of the plurality of drawing units, A switching control unit for supplying a drive signal for deflection to one of the plurality of selection optical members, and the selection optical unit to which the drive signal is provided among the plurality of selection optical members. It detects the intensity of the beam undeflected state transmitted through, and a beam intensity measuring unit for measuring the intensity of the beam, each supplied to the plurality of rendering units.

  According to a fourth aspect of the present invention, there is provided a pattern drawing device for drawing a pattern on the substrate by a plurality of drawing units for drawing a pattern by scanning a beam from the light source device on the substrate with a scanning member. Acousto-optic modulation elements for deflecting the beam from the apparatus toward the drawing unit are provided corresponding to each of the plurality of drawing units, and the beam from the light source apparatus is provided to each of the plurality of acousto-optic modulation elements. A plurality of acoustooptics so as to sequentially supply a beam from the light source device to one of the plurality of drawing units. A control unit that switches one of the modulation elements to a deflected state, and a non-deflection state that is transmitted through the acousto-optic modulation element that is in a deflection state among the plurality of acousto-optic modulation elements Of detecting the intensity of the beam, and a beam intensity measuring unit for measuring the intensity of the beam, each supplied to the plurality of rendering units.

1 is a perspective view showing a schematic overall configuration of a pattern drawing apparatus according to a first embodiment. It is a perspective view which shows the specific structure of the drawing unit mounted in the pattern drawing apparatus shown in FIG. It is a figure which shows the specific optical arrangement | positioning of the optical element for selection shown in FIG. 1, and an incident mirror. It is a figure which shows schematic structure of the beam switching part and drawing control apparatus for selectively distributing the beam from a light source device to either of six drawing units. FIG. 5 is a diagram for explaining a connection relationship between an intensity adjustment control unit, a drive circuit, and the like provided in the drawing control apparatus shown in FIG. 4. It is a graph which shows an example of the change characteristic of the diffraction efficiency by the change of RF electric power of the drive signal applied to the optical element for selection. It is the graph which showed typically an example of the relationship between the intensity | strength of the beam supplied to each of drawing unit, and the adjustable range in the optical element for selection which adjusts the intensity | strength of the beam. It is a figure which illustrates typically the influence by each efficiency and the transmittance | permeability of several optical element for selection arranged in series along the advancing direction of the beam from a light source device.

  DESCRIPTION OF EMBODIMENTS A pattern drawing apparatus according to an aspect of the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. In addition, the aspect of this invention is not limited to these embodiment, What added the various change or improvement is included. That is, the constituent elements described below include those that can be easily assumed by those skilled in the art and substantially the same elements, and the constituent elements described below can be appropriately combined. In addition, various omissions, substitutions, or changes of the components can be made without departing from the scope of the present invention.

[First Embodiment]
FIG. 1 is a perspective view showing a schematic configuration of a pattern drawing apparatus (hereinafter also referred to as an exposure apparatus) EX that performs an exposure process on a substrate (object to be irradiated) P according to the first embodiment. In the following description, unless otherwise specified, an XYZ orthogonal coordinate system in which the gravity direction is the Z direction is set, and the X direction, the Y direction, and the Z direction will be described according to the arrows shown in the drawing.

  The pattern drawing apparatus EX is a substrate processing apparatus used in a device manufacturing system for manufacturing an electronic device by performing predetermined processing (such as exposure processing) on the substrate P. The device manufacturing system is a manufacturing system in which a manufacturing line for manufacturing, for example, a flexible display as an electronic device, a film-like touch panel, a film-like color filter for a liquid crystal display panel, flexible wiring, or a flexible sensor is constructed. System. The following description is based on the assumption that a flexible display is used as the electronic device. Examples of the flexible display include an organic EL display and a liquid crystal display. In the device manufacturing system, a substrate P is sent from a supply roll (not shown) in which a flexible sheet-like substrate (sheet substrate) P is wound in a roll shape, and various processes are continuously performed on the sent substrate P. After the application, the substrate P after various treatments is taken up by a collection roll (not shown), so-called roll-to-roll production method. Therefore, the substrate P after various treatments is a multi-sided substrate in which a plurality of devices (display panels) are arranged in a state where they are connected in the transport direction of the substrate P. The substrate P sent from the supply roll is sequentially subjected to various processes through the process device in the previous process, the pattern drawing apparatus EX, and the process apparatus in the subsequent process, and is taken up by the collection roll. The substrate P has a belt-like shape in which the moving direction (transport direction) of the substrate P is the longitudinal direction (long direction) and the width direction is the short direction (short direction).

  For the substrate P, for example, a resin film or a foil (foil) made of a metal or alloy such as stainless steel is used. Examples of the resin film material include polyethylene resin, polypropylene resin, polyester resin, ethylene vinyl copolymer resin, polyvinyl chloride resin, cellulose resin, polyamide resin, polyimide resin, polycarbonate resin, polystyrene resin, and vinyl acetate resin. Among them, one containing at least one or more may be used. Further, the thickness and rigidity (Young's modulus) of the substrate P are within a range in which a fold due to buckling or irreversible wrinkles does not occur in the substrate P when passing through the conveyance path of the device manufacturing system or the pattern drawing apparatus EX. If it is. As a base material of the substrate P, a film such as PET (polyethylene terephthalate) or PEN (polyethylene naphthalate) having a thickness of about 25 μm to 200 μm is typical of a suitable sheet substrate.

  Since the substrate P may receive heat in each process performed in the device manufacturing system, it is preferable to select the substrate P made of a material whose thermal expansion coefficient is not significantly large. For example, the thermal expansion coefficient can be suppressed by mixing an inorganic filler with a resin film. The inorganic filler may be, for example, titanium oxide, zinc oxide, alumina, or silicon oxide. Further, the substrate P may be a single layer of ultrathin glass having a thickness of about 100 μm manufactured by a float process or the like, or a laminate in which the above resin film, foil, etc. are bonded to the ultrathin glass. It may be.

  By the way, the flexibility of the substrate P means the property that the substrate P can be bent without being sheared or broken even when a force of its own weight is applied to the substrate P. . In addition, flexibility includes a property of bending by a force of about its own weight. The degree of flexibility varies depending on the material, size, and thickness of the substrate P, the layer structure formed on the substrate P, the environment such as temperature or humidity, and the like. In any case, when the substrate P is correctly wound around various conveyance rollers, rotary drums, or other members for conveyance direction provided in the conveyance path in the device manufacturing system (pattern drawing apparatus EX), the substrate P buckles and folds. If the substrate P can be smoothly transported without being damaged or broken (breaking or cracking), it can be said to be in the range of flexibility.

  The process device in the previous process (including a single processing unit or a plurality of processing units) transports the substrate P sent from the supply roll along the longitudinal direction at a predetermined speed toward the pattern drawing device EX. Meanwhile, the previous process is performed on the substrate P sent to the pattern drawing apparatus EX. The substrate P sent to the pattern writing apparatus EX by this pre-process is a substrate (photosensitive substrate) having a photosensitive functional layer (photosensitive layer) formed on the surface thereof.

  This photosensitive functional layer is applied on the substrate P as a solution and dried to form a layer (film). A typical photosensitive functional layer is a photoresist (in liquid or dry film form), but as a material that does not require development processing, the photosensitivity of the part that has been irradiated with ultraviolet rays is modified. There is a silane coupling agent (SAM) or a photosensitive reducing agent in which a plating reducing group is exposed in a portion irradiated with ultraviolet rays. When a photosensitive silane coupling agent is used as the photosensitive functional layer, the pattern portion exposed to ultraviolet rays on the substrate P is modified from lyophobic to lyophilic. Therefore, a thin film transistor (TFT) or the like can be formed by selectively applying a conductive ink (ink containing conductive nanoparticles such as silver or copper) or a liquid containing a semiconductor material on the lyophilic portion. A pattern layer to be an electrode, a semiconductor, insulation, or a wiring for connection can be formed. When a photosensitive reducing agent is used as the photosensitive functional layer, the plating reducing group is exposed to the pattern portion exposed to ultraviolet rays on the substrate P. Therefore, after exposure, the substrate P is immediately immersed in a plating solution containing palladium ions for a certain period of time, so that a pattern layer of palladium is formed (deposited). Such a plating process is an additive process, but may be based on an etching process as a subtractive process. In that case, the substrate P sent to the pattern writing apparatus EX is made of PET or PEN as a base material, and a metal thin film such as aluminum (Al) or copper (Cu) is deposited on the entire surface or selectively, and further, It is preferable that a photoresist layer is laminated thereon.

  The pattern drawing apparatus EX transfers the substrate P, which has been transported from the process device in the previous process, to the process device (including a single processing unit or a plurality of processing units) at a predetermined speed while transporting the substrate P at a predetermined speed. A processing apparatus that performs an exposure process on P. The pattern drawing apparatus EX corresponds to a pattern for an electronic device (for example, a pattern of electrodes and wiring of TFTs constituting the electronic device) on the surface of the substrate P (the surface of the photosensitive functional layer, that is, the photosensitive surface). Irradiate a light pattern. Thereby, a latent image (modified portion) corresponding to the pattern is formed on the photosensitive functional layer.

  In the present embodiment, the pattern drawing apparatus EX is a direct drawing type exposure apparatus that does not use a mask as shown in FIG. 1, that is, a so-called spot scanning type exposure apparatus (drawing apparatus). The exposure apparatus EX performs pattern exposure for each part of the rotating drum DR that supports the substrate P and conveys it in the longitudinal direction for sub-scanning, and the substrate P that is supported in a cylindrical surface by the rotating drum DR. Here, six drawing units Un (U1 to U6) are provided, and each of the plurality of drawing units Un (U1 to U6) receives spot light SP of a pulse beam LB (pulse beam) for exposure, The intensity of the spot light SP is measured with pattern data (drawing data) while one-dimensionally scanning (main scanning) with a polygon mirror (scanning member) in a predetermined scanning direction (Y direction) on the irradiated surface (photosensitive surface) of the substrate P. , Modulation (on / off) at high speed according to the pattern information). Thereby, a light pattern corresponding to a predetermined pattern such as an electronic device, a circuit, or a wiring is drawn and exposed on the irradiated surface of the substrate P. That is, the spot light SP is relatively two-dimensionally scanned on the surface to be irradiated (the surface of the photosensitive functional layer) of the substrate P by the sub-scanning of the substrate P and the main scanning of the spot light SP. A predetermined pattern is drawn and exposed on the irradiated surface. In addition, since the substrate P is transported along the longitudinal direction, a plurality of exposed areas where the pattern is exposed by the exposure apparatus EX are provided at predetermined intervals along the longitudinal direction of the substrate P. It will be. Since an electronic device is formed in this exposed region, the exposed region is also a device forming region.

  As shown in FIG. 1, the rotary drum DR has a central axis AXo extending in the Y direction and extending in a direction intersecting with the direction in which gravity works, and a cylindrical outer peripheral surface having a constant radius from the central axis AXo. The rotating drum DR rotates around the central axis AXo while supporting (holding) a part of the substrate P by bending the outer surface (circumferential surface) into a cylindrical surface in the longitudinal direction. P is transported in the longitudinal direction. The rotating drum DR supports an area (portion) on the substrate P onto which the beam LB (spot light SP) from each of the plurality of drawing units Un (U1 to U6) is projected on its outer peripheral surface. The rotating drum DR supports (holds and holds) the substrate P from the surface (back surface) opposite to the surface on which the electronic device is formed (surface on which the photosensitive surface is formed). In addition, on both sides in the Y direction of the rotating drum DR, shafts (not shown) supported by bearings are provided so as to rotate the rotating drum DR around the central axis AXo. The shaft is given a rotational torque from a rotational drive source (not shown) (for example, a motor or a speed reduction mechanism), and the rotary drum DR rotates around the central axis AXo at a constant rotational speed.

  The light source device (pulse light source device) LS generates and emits a pulsed beam (pulse beam, pulsed light, laser) LB. This beam LB is ultraviolet light having sensitivity to the photosensitive layer of the substrate P and having a peak wavelength in a wavelength band of 370 nm or less. The light source device LS emits a beam LB that emits pulses at a frequency (oscillation frequency, predetermined frequency) Fa according to control of a drawing control device 200 (not illustrated) (described in FIG. 4). The light source device LS includes a semiconductor laser element that generates pulsed light in the infrared wavelength range, a fiber amplifier, and a wavelength conversion element (harmonic) that converts the amplified pulsed light in the infrared wavelength range into pulsed light in the ultraviolet wavelength range. A fiber amplifier laser light source including a wave generating element). By configuring the light source device LS in this manner, high-intensity ultraviolet pulsed light having an oscillation frequency Fa of several hundred MHz and a light emission time of one pulse of several tens of picoseconds or less can be obtained. It is assumed that the beam LB emitted from the light source device LS is a thin parallel light beam having a beam diameter of about 1 mm or less. For example, a configuration in which the light source device LS is a fiber amplifier laser light source and the pulse generation of the beam LB is turned on / off at high speed according to the state of the pixels constituting the drawing data (logical value “0” or “1”). Disclosed in International Publication No. 2015/166910.

  A beam LB emitted from the light source device LS includes a selection optical element OSn (OS1 to OS6) as a plurality of switching elements, a plurality of reflection mirrors M1 to M12, a plurality of incident mirrors IMn (IM1 to IM6), It is selectively (alternatively) supplied to each of the drawing units Un (U1 to U6) via a beam switching unit composed of an absorber TR or the like. The selection optical element OSn (OS1 to OS6) is transmissive to the beam LB, is driven by an ultrasonic signal, and the first-order diffracted light of the incident beam LB is used as a drawing beam LBn. It comprises an acousto-optic modulator (AOM: Acousto-Optic Modulator) that deflects and emits at an angle. The plurality of selection optical elements OSn and the plurality of incident mirrors IMn are provided corresponding to each of the plurality of drawing units Un. For example, the selection optical element OS1 and the incident mirror IM1 are provided corresponding to the drawing unit U1, and similarly, the selection optical element OS2 to OS6 and the incident mirror IM2 to IM6 correspond to the drawing units U2 to U6, respectively. Is provided.

  The light beam LB from the light source device LS is guided to the absorber TR by the reflection mirrors M1 to M12 whose optical path is bent in a plane parallel to the XY plane. Hereinafter, the case where all of the selection optical elements OSn (OS1 to OS6) are in an off state (a state where no ultrasonic signal is applied and no first-order diffracted light is generated) will be described in detail. Although not shown in FIG. 1, a plurality of lenses (optical elements) are provided in the beam optical path from the reflection mirror M1 to the absorber TR, and the plurality of lenses converge the beam LB from the parallel light flux. Or the beam LB that diverges after convergence is returned to a parallel light flux. The configuration will be described later with reference to FIG.

  In FIG. 1, the beam LB from the light source device LS travels in the −X direction parallel to the X axis and enters the reflection mirror M1. The beam LB reflected in the −Y direction by the reflection mirror M1 enters the reflection mirror M2. The beam LB reflected in the + X direction by the reflection mirror M2 passes through the selection optical element OS5 linearly and reaches the reflection mirror M3. The beam LB reflected in the −Y direction by the reflection mirror M3 enters the reflection mirror M4. The beam LB reflected in the −X direction by the reflection mirror M4 is linearly transmitted through the selection optical element OS6 and reaches the reflection mirror M5. The beam LB reflected in the −Y direction by the reflection mirror M5 enters the reflection mirror M6. The beam LB reflected in the + X direction by the reflection mirror M6 is linearly transmitted through the selection optical element OS3 and reaches the reflection mirror M7. The beam LB reflected in the −Y direction by the reflection mirror M7 enters the reflection mirror M8. The beam LB reflected in the −X direction by the reflection mirror M8 is linearly transmitted through the selection optical element OS4 and reaches the reflection mirror M9. The beam LB reflected in the −Y direction by the reflection mirror M9 enters the reflection mirror M10. The beam LB reflected in the + X direction by the reflection mirror M10 is linearly transmitted through the selection optical element OS1 and reaches the reflection mirror M11. The beam LB reflected in the −Y direction by the reflection mirror M11 enters the reflection mirror M12. The beam LB reflected by the reflecting mirror M12 in the −X direction is linearly transmitted through the selection optical element OS2 and guided to the absorber TR. The absorber TR is an optical trap that absorbs the beam LB in order to suppress leakage of the beam LB to the outside.

  When an ultrasonic signal (high frequency signal) is applied to each of the optical elements for selection OSn, an incident beam (0th order light) LB is radiated as a first order diffracted light with a diffraction angle corresponding to a high frequency. It is generated as (drawing beam LBn). Therefore, the beam emitted as the first-order diffracted light from the selection optical element OS1 is LB1, and similarly, the beams emitted as the first-order diffracted light from the selection optical elements OS2 to OS6 are LB2 to LB6. Thus, each selection optical element OSn (OS1 to OS6) has a function of deflecting the optical path of the beam LB from the light source device LS. In this embodiment, the selection optical element OSn (OS1 to OS6) is turned on to generate the beam LBn (LB1 to LB6) as the first-order diffracted light. In the following description, it is assumed that OS1 to OS6) deflect (or select) the beam LB from the light source device LS. However, since the maximum generation efficiency of the first-order diffracted light is about 80% of the 0th-order light in the actual acoustooptic modulator, the beams LBn (LB1 to LB6) deflected by each of the selection optical elements OSn are It is lower than the intensity of the original beam LB. In the present embodiment, the drawing control device 200 (see FIG. 4) controls the selected optical element OSn (OS1 to OS6) so that only one of the selected optical elements OSn (OS1 to OS6) is turned on for a predetermined time. The When one selected optical element OSn is in the ON state, about 20% of zero-order light that travels straight without being diffracted by the optical element for selection OSn remains, but it is finally absorbed by the absorber TR. The

  Each of the selection optical elements OSn is installed so as to deflect the drawing beam LBn (LB1 to LB6), which is the deflected first-order diffracted light, in the −Z direction with respect to the incident beam LB. Beams LBn (LB1 to LB6) that are deflected and emitted from each of the selection optical elements OSn are projected onto incident mirrors IMn (IM1 to IM6) provided at positions separated from each of the selection optical elements OSn by a predetermined distance. Is done. Each incident mirror IMn guides the beam LBn (LB1 to LB6) to the corresponding drawing unit Un (U1 to U6) by reflecting the incident beam LBn (LB1 to LB6) in the −Z direction.

  The same configuration, function, action, and the like of each selection optical element OSn may be used. Each of the plurality of optical elements for selection OSn turns on / off generation of diffracted light (beam LBn) obtained by diffracting the incident beam LB in accordance with on / off of a drive signal (ultrasonic signal) from the drawing control apparatus 200. Turn off. For example, the selection optical element OS5 transmits the beam LB from the incident light source device LS without being deflected (diffracted) when the drive signal (high frequency signal) from the drawing control device 200 is not applied and is in the off state. . Therefore, the beam LB transmitted through the selection optical element OS5 enters the reflection mirror M3. On the other hand, when the selection optical element OS5 is in the on state, the incident beam LB is deflected (diffracted) and directed to the incident mirror IM5. That is, the switching (beam selection) operation by the selection optical element OS5 is controlled by turning on / off the drive signal. In this way, the switching operation of each selection optical element OSn can guide the beam LB from the light source device LS to any one drawing unit Un, and switch the drawing unit Un on which the beam LBn is incident. Can do. As described above, the plurality of selection optical elements OSn are arranged in series so that the beams LB from the light source device LS pass in order, and the beams LBn are supplied to the corresponding drawing units Un in a time division manner. Is disclosed in International Publication No. 2015/166910.

  The order in which each of the selection optical elements OSn (OS1 to OS6) constituting the beam switching unit is turned on for a predetermined time is, for example, OS1 → OS2 → OS3 → OS4 → OS5 → OS6 → OS1 →. Are predetermined. This order is determined by the order of the scanning start timing by the spot light set in each of the drawing units Un (U1 to U6). That is, in the present embodiment, any one of the drawing units U1 to U6 is synchronized with the rotation speed of the polygon mirror provided in each of the six drawing units U1 to U6 in synchronization with the rotation angle phase. It is possible to switch to the time division so that one reflection surface of the polygon mirror in one of them performs one spot scanning on the substrate P. Therefore, the order of spot scanning of the drawing unit Un may be any as long as the phase of the rotation angle of each polygon mirror of the drawing unit Un is synchronized in a predetermined relationship. In the configuration of FIG. 1, three drawing units U1, U3, U5 are arranged in the Y direction on the upstream side in the transport direction of the substrate P (the direction in which the outer peripheral surface of the rotary drum DR moves in the circumferential direction). Three drawing units U2, U4, U6 are arranged in the Y direction on the downstream side in the transport direction.

  In this case, pattern drawing on the substrate P is started from the upstream odd-numbered drawing units U1, U3, U5, and when the substrate P is fed for a certain length, the even-numbered drawing units U2, U4, U6 on the downstream side. Since pattern drawing is also started, the order of spot scanning of the drawing unit Un can be set as U1 → U3 → U5 → U2 → U4 → U6 → U1 →. Therefore, the order in which each of the selection optical elements OSn (OS1 to OS6) is turned on for a predetermined time is determined as follows: OS1 → OS3 → OS5 → OS2 → OS4 → OS6 → OS1 →. Even when the selection optical element OSn corresponding to the drawing unit Un having no pattern to be drawn is in the turn-on order, the on / off switching control of the selection optical element OSn is based on the drawing data. By doing so, the selection optical element OSn is forcibly maintained in the OFF state, so that spot scanning by the drawing unit Un is not performed.

  As shown in FIG. 1, each of the drawing units U1 to U6 is provided with a polygon mirror PM for main scanning the incident beams LB1 to LB6. In the present embodiment, the polygon mirrors PM of the respective drawing units Un are synchronously controlled so as to maintain a constant rotational angle phase with each other while precisely rotating at the same rotational speed. Thereby, the main scanning timing (main scanning period of the spot light SP) of each of the beams LB1 to LB6 projected onto the substrate P from each of the drawing units U1 to U6 can be set so as not to overlap each other. Accordingly, the on / off switching of each of the selection optical elements OSn (OS1 to OS6) provided in the beam switching unit is controlled in synchronization with the rotation angle positions of the six polygon mirrors PM, thereby providing a light source. An efficient exposure process can be performed in which the beam LB from the apparatus LS is distributed in time division to each of the plurality of drawing units Un.

  The synchronization of the phase adjustment of the rotation angles of each of the six polygon mirrors PM and the on / off switching timings of the optical elements for selection OSn (OS1 to OS6) is described in International Publication No. 2015/166910. Although disclosed, in the case of the 8-sided polygon mirror PM, about 1/3 of the rotation angle (45 degrees) of one reflecting surface is one scan of the spot light SP on the substrate P as the scanning efficiency. 6 polygon mirrors PM are rotated by shifting the phase of the rotation angle by 15 degrees relative to each other, and each polygon mirror PM scans the beam LBn by skipping one of the eight reflecting surfaces. The on / off switching of each of the optical elements OSn (OS1 to OS6) is controlled. As described above, a drawing method using one reflecting surface of the polygon mirror PM is also disclosed in International Publication No. 2015/166910.

  As shown in FIG. 1, the exposure apparatus EX is a so-called multi-head direct drawing exposure apparatus in which a plurality of drawing units Un (U1 to U6) having the same configuration are arranged. Each of the drawing units Un draws a pattern for each partial region partitioned in the Y direction of the substrate P supported by the outer peripheral surface (circumferential surface) of the rotary drum DR. Each drawing unit Un (U1 to U6) condenses (converges) the beam LBn on the substrate P while projecting the beam LBn from the beam switching unit onto the substrate P (on the irradiated surface of the substrate P). Thereby, the beam LBn (LB1 to LB6) projected on the substrate P becomes the spot light SP. Further, the spot light SP of the beam LBn (LB1 to LB6) projected on the substrate P is scanned in the main scanning direction (Y direction) by the rotation of the polygon mirror PM of each drawing unit Un. By scanning with the spot light SP, a linear drawing line (scanning line) SLn (n = 1, 2,..., 6) for drawing a pattern for one line is defined on the substrate P. Is done. The drawing line SLn is also a scanning locus on the substrate P of the spot light SP of the beam LBn.

  The drawing unit U1 scans the spot light SP along the drawing line SL1, and similarly, the drawing units U2 to U6 scan the spot light SP along the drawing lines SL2 to SL6. As shown in FIG. 1, the drawing lines SLn (SL1 to SL6) of the plurality of drawing units Un (U1 to U6) include a central plane that includes the central axis AXo of the rotary drum DR and is parallel to the YZ plane. It is arranged in a staggered arrangement in two rows in the circumferential direction of DR. The odd-numbered drawing lines SL1, SL3, and SL5 are located on the irradiated surface of the substrate P on the upstream side (−X direction side) in the transport direction of the substrate P with respect to the center surface, and along the Y direction. They are arranged in a row at a predetermined interval. The even-numbered drawing lines SL2, SL4, SL6 are located on the irradiated surface of the substrate P on the downstream side (+ X direction side) in the transport direction of the substrate P with respect to the center surface, and are predetermined along the Y direction. Are arranged in a row separated by an interval of. Therefore, the plurality of drawing units Un (U1 to U6) are also arranged in a staggered arrangement in two rows in the transport direction of the substrate P across the center plane, and the odd-numbered drawing units U1, U3, U5 and the even-numbered drawing The units U2, U4, and U6 are provided symmetrically with respect to the center plane when viewed in the XZ plane.

  Regarding the X direction (the transport direction of the substrate P or the sub-scanning direction), the odd-numbered drawing lines SL1, SL3, SL5 and the even-numbered drawing lines SL2, SL4, SL6 are separated from each other, but the Y direction ( With respect to the width direction of the substrate P and the main scanning direction), they are set to be joined together without being separated from each other. The drawing lines SL1 to SL6 are substantially parallel to the width direction of the substrate P, that is, the central axis AXo of the rotary drum DR. Note that splicing the drawing line SLn in the Y direction means that the end of the drawing line SLn is such that the pattern drawn in each of the drawing lines SLn adjacent in the Y direction is spliced in the Y direction on the substrate P. This means that the positions in the Y direction are adjacent or partially overlapped. When overlapping the end portions of the drawing lines SLn, for example, the length of each drawing line SLn may be overlapped within a range of several percent or less in the Y direction including the drawing start point or the drawing end point. .

  As described above, the plurality of drawing units Un (U1 to U6) share the Y-direction scanning region (the main scanning range section) so as to cover the widthwise dimension of the exposure region on the substrate P in total. ing. For example, if the main scanning range in the Y direction (the length of the drawing line SLn) by one drawing unit Un is about 30 to 60 mm, drawing can be performed by arranging a total of six drawing units U1 to U6 in the Y direction. The width of the exposure area in the Y direction is increased to about 180 to 360 mm. The length of each drawing line SLn (SL1 to SL6) (length of the drawing range) is basically the same. That is, the scanning distance of the spot light SP of the beam LBn scanned along each of the drawing lines SL1 to SL6 is basically the same.

In the case of the present embodiment, when the beam LB from the light source device LS is pulsed light having a light emission time of several tens of picoseconds or less, the spot light SP projected on the drawing line SLn during the main scanning is the beam It becomes discrete according to the oscillation frequency Fa (for example, 400 MHz) of the LB. Therefore, it is necessary to overlap the spot light SP projected by one pulse light of the beam LB and the spot light SP projected by the next one pulse light in the main scanning direction. The amount of overlap is set by the size φ of the spot light SP, the scanning speed (main scanning speed) Vs of the spot light SP, and the oscillation frequency Fa of the beam LB. The effective size (diameter) φ of the spot light SP is 1 / e ² (or 1/2) of the peak intensity of the spot light SP when the intensity distribution of the spot light SP is approximated by a Gaussian distribution. Determined by the width dimension. In the present embodiment, the scanning speed Vs of the spot light SP (rotational speed of the polygon mirror PM) and the spot light SP so that the spot light SP overlaps the effective size (dimension) φ by about φ × ½. The oscillation frequency Fa is set. Therefore, the projection interval along the main scanning direction of the pulsed spot light SP is φ / 2. Therefore, also in the sub-scanning direction (direction intersecting with the drawing line SLn), the substrate P is effective for the spot light SP between one scanning of the spot light SP along the drawing line SLn and the next scanning. It is desirable to set so as to move by a distance of about ½ of a large size φ. Further, when drawing lines SLn adjacent in the Y direction are continued in the main scanning direction, it is desirable to overlap by φ / 2. In the present embodiment, the size (dimension) φ of the spot light SP is about 3 to 4 μm.

  Each drawing unit Un (U1 to U6) is set such that each beam LBn travels toward the central axis AXo of the rotary drum DR when viewed in the XZ plane. Thereby, the optical path (beam principal ray) of the beam LBn traveling from each drawing unit Un (U1 to U6) toward the substrate P becomes parallel to the normal line of the irradiated surface of the substrate P in the XZ plane. Further, the beam LBn irradiated from the respective drawing units Un (U1 to U6) to the drawing lines SLn (SL1 to SL6) is relative to the tangential plane at the drawing line SLn on the surface of the substrate P curved in a cylindrical surface shape. It is projected toward the substrate P so as to be always vertical. That is, with respect to the main scanning direction of the spot light SP, the beams LBn (LB1 to LB6) projected onto the substrate P are scanned in a telecentric state.

  Since the drawing unit (beam scanning device) Un shown in FIG. 1 has the same configuration, only the drawing unit U1 will be described briefly. The detailed configuration of the drawing unit U1 will be described later with reference to FIG. The drawing unit U1 includes at least reflection mirrors M20 to M24, a polygon mirror PM, and an fθ lens system (drawing scanning lens) FT. Although not shown in FIG. 1, a first cylindrical lens CYa (see FIG. 2) is disposed in front of the polygon mirror PM when viewed from the traveling direction of the beam LB1, and an fθ lens system (f-θ lens system). ) A second cylindrical lens CYb (see FIG. 2) is provided after the FT. The first cylindrical lens CYa and the second cylindrical lens CYb correct the position variation of the spot light SP (drawing line SL1) in the sub-scanning direction due to the tilt error of each reflecting surface of the polygon mirror PM.

  The beam LB1 reflected in the −Z direction by the incident mirror IM1 enters the reflection mirror M20 provided in the drawing unit U1, and the beam LB1 reflected by the reflection mirror M20 advances in the −X direction and enters the reflection mirror M21. To do. The beam LB1 reflected in the −Z direction by the reflection mirror M21 enters the reflection mirror M22, and the beam LB1 reflected by the reflection mirror M22 advances in the + X direction and enters the reflection mirror M23. The reflection mirror M23 reflects the incident beam LB1 toward the reflection surface RP of the polygon mirror PM so as to be bent in a plane parallel to the XY plane.

  The polygon mirror PM reflects the incident beam LB1 toward the + θ direction toward the fθ lens system FT. The polygon mirror PM deflects (reflects) the incident beam LB1 one-dimensionally in a plane parallel to the XY plane in order to scan the spot light SP of the beam LB1 on the irradiated surface of the substrate P. Specifically, the polygon mirror (rotating polygonal mirror, scanning member) PM includes a rotation axis AXp extending in the Z-axis direction, and a plurality of reflecting surfaces RP (mainly formed around the rotation axis AXp and in parallel with the rotation axis AXp). In the embodiment, the number Np of the reflecting surfaces RP is 8). The reflection angle of the pulsed beam LB1 irradiated on the reflection surface can be continuously changed by rotating the polygon mirror PM around the rotation axis AXp in a predetermined rotation direction. As a result, the beam LB1 is deflected by one reflecting surface RP, and the spot light SP of the beam LB1 irradiated on the irradiated surface of the substrate P is scanned along the main scanning direction (the width direction of the substrate P, the Y direction). can do. For this reason, the number of drawing lines SL1 in which the spot light SP is scanned on the irradiated surface of the substrate P by one rotation of the polygon mirror PM is eight, which is the same as the number of the reflecting surfaces RP.

  The fθ lens system (scanning system lens, scanning optical system) FT is a telecentric scan lens that projects the beam LB1 reflected by the polygon mirror PM onto the reflection mirror M24. The beam LB1 transmitted through the fθ lens system FT is projected onto the substrate P as the spot light SP through the reflection mirror M24. At this time, the reflection mirror M24 reflects the beam LB1 toward the substrate P so that the beam LB1 travels toward the central axis AXo of the rotary drum DR with respect to the XZ plane. The incident angle θ of the beam LB1 to the fθ lens system FT varies depending on the rotation angle (θ / 2) of the polygon mirror PM. The fθ lens system FT projects the beam LB1 to the image height position on the irradiated surface of the substrate P in proportion to the incident angle θ through the reflection mirror M24. When the focal length of the fθ lens system FT is fo and the image height position is yo, the fθ lens system FT is designed to satisfy the relationship (distortion aberration) of yo = fo × θ. Therefore, the beam LB1 can be scanned in the Y direction accurately at a constant speed by the fθ lens system FT. Note that a surface (parallel to the XY plane) on which the beam LB1 incident on the fθ lens system FT is deflected in one dimension by the polygon mirror PM is a surface including the optical axis AXf of the fθ lens system FT.

  Next, the optical configuration of the drawing unit Un (U1 to U6) will be described with reference to FIG. As shown in FIG. 2, in the drawing unit Un, along the traveling direction of the beam LBn from the incident position of the beam LBn to the irradiated surface (substrate P), the reflection mirror M20, the reflection mirror M20a, and the polarization beam splitter BS1. , A reflection mirror M21, a reflection mirror M22, a first cylindrical lens CYa, a reflection mirror M23, a polygon mirror PM, an fθ lens system FT, a reflection mirror M24, and a second cylindrical lens CYb. Further, in the drawing unit Un, an origin sensor (origin detection) that detects the angular position of each reflecting surface of the polygon mirror PM in order to detect the drawing start possible timing (scanning start timing of the spot light SP) of the drawing unit Un. A beam transmitting system 60a and a beam receiving system 60b are provided. In the drawing unit Un, the reflected light of the beam LBn reflected by the irradiated surface of the substrate P (or the surface of the rotating drum DR) is converted into the fθ lens system FT, the polygon mirror PM, the polarization beam splitter BS1, and the like. A photodetector (photoelectric sensor) DTc for detection via the DTc is provided.

  The beam LBn incident on the drawing unit Un travels in the −Z direction along the optical axis AX1 parallel to the Z axis, and enters the reflection mirror M20 inclined by 45 ° with respect to the XY plane. The beam LBn reflected by the reflection mirror M20 travels in the −X direction toward the reflection mirror M20a that is separated from the reflection mirror M20 in the −X direction. The reflection mirror M20a is disposed with an inclination of 45 ° with respect to the YZ plane, and reflects the incident beam LBn toward the polarization beam splitter BS1 in the −Y direction. The polarization separation surface of the polarization beam splitter BS1 is disposed at an angle of 45 ° with respect to the YZ plane, reflects a P-polarized beam, and transmits a linearly polarized (S-polarized) beam polarized in a direction orthogonal to the P-polarized light. When the beam LBn incident on the drawing unit Un is a P-polarized beam, the polarization beam splitter BS1 reflects the beam LBn from the reflection mirror M20a in the −X direction and guides it to the reflection mirror M21 side. The reflection mirror M21 is disposed at an angle of 45 ° with respect to the XY plane, and reflects the incident beam LBn in the −Z direction toward the reflection mirror M22 that is separated from the reflection mirror M21 in the −Z direction. The beam LBn reflected by the reflection mirror M21 enters the reflection mirror M22. The reflection mirror M22 is disposed with an inclination of 45 ° with respect to the XY plane, and reflects the incident beam LBn toward the reflection mirror M23 in the + X direction. The beam LBn reflected by the reflection mirror M22 enters the reflection mirror M23 via a λ / 4 wavelength plate (not shown) and a cylindrical lens CYa. The reflection mirror M23 reflects the incident beam LBn toward the polygon mirror PM.

  The polygon mirror PM reflects the incident beam LBn toward the + X direction toward an fθ lens system FT having an optical axis AXf parallel to the X axis. The polygon mirror PM deflects (reflects) the incident beam LBn one-dimensionally in a plane parallel to the XY plane in order to scan the spot light SP of the beam LBn on the irradiated surface of the substrate P. The polygon mirror PM has a plurality of reflecting surfaces (each side of a regular octagon in this embodiment) formed around a rotation axis AXp extending in the Z-axis direction, and is rotated by a rotation motor RM coaxial with the rotation axis AXp. Is done. The rotation motor RM rotates at a constant rotation speed (for example, about 30,000 to 40,000 rpm) by a polygon rotation control unit provided in the drawing control apparatus 200 (see FIG. 4). As described above, the effective length (for example, 50 mm) of the drawing lines SLn (SL1 to SL6) is the maximum scanning length (for example, 52 mm) at which the spot light SP can be scanned by the polygon mirror PM. The length is set as follows, and in the initial setting (design), the center point of the drawing line SLn (the point through which the optical axis AXf of the fθ lens system FT passes) is set at the center of the maximum scanning length.

  The cylindrical lens CYa converges the incident beam LBn on the reflection surface of the polygon mirror PM in the sub-scanning direction (Z direction) orthogonal to the main scanning direction (rotation direction) of the polygon mirror PM. That is, the cylindrical lens CYa converges the beam LBn in a slit shape (ellipse shape) extending in a direction parallel to the XY plane on the reflection surface of the polygon mirror PM. Even when the reflection surface of the polygon mirror PM is tilted from a state parallel to the Z axis (rotation axis AXp) by a cylindrical lens CYa whose generating line is parallel to the Y direction and a cylindrical lens CYb described later, It is possible to prevent the irradiation position of the beam LBn (drawing line SLn) irradiated on the irradiated surface of the substrate P from shifting in the sub-scanning direction.

  An incident angle θ of the beam LBn to the fθ lens system FT (an angle with respect to the optical axis AXf) changes according to the rotation angle (θ / 2) of the polygon mirror PM. When the incident angle θ of the beam LBn to the fθ lens system FT is 0 degree, the beam LBn incident on the fθ lens system FT advances along the optical axis AXf. The beam LBn from the fθ lens system FT is reflected in the −Z direction by the reflection mirror M24, and is projected toward the substrate P through the cylindrical lens CYb. The beam LBn projected onto the substrate P by the fθ lens system FT and the cylindrical lens CYb whose generating line is parallel to the Y direction is a minute spot light having a diameter of about several μm (for example, 2 to 3 μm) on the irradiated surface of the substrate P. Converged to SP. As described above, the beam LBn incident on the drawing unit Un is bent along the optical path cranked in a U-shape from the reflection mirror M20 to the substrate P when viewed in the XZ plane, and proceeds in the −Z direction to the substrate. Projected to P. Each of the six drawing units U1 to U6 scans the spot lights SP of the beams LB1 to LB6 in one dimension in the main scanning direction (Y direction) and conveys the substrate P in the longitudinal direction, thereby The irradiated surface is relatively two-dimensionally scanned with the spot light SP, and the pattern drawn on each of the drawing lines SL1 to SL6 is exposed on the substrate P in a state where the patterns are joined in the Y direction.

As an example, the effective scanning length LT of the drawing lines SLn (SL1 to SL6) is 50 mm, the effective diameter φ of the spot light SP is 4 μm, and the oscillation frequency Fa of the pulse emission of the beam LB from the light source device LS is 400 MHz. When the pulsed light is emitted so that the spot light SP overlaps by 1/2 of the diameter φ along the drawing line SLn (main scanning direction), the interval of the pulsed light emission of the spot light SP in the main scanning direction is 2 μm, which corresponds to 2.5 nS (1/400 MHz) which is the period Tf (= 1 / Fa) of the oscillation frequency Fa. In this case, the pixel size Pxy defined on the drawing data is set to 4 μm square on the substrate P, and one pixel is exposed by two pulses of the spot light SP in each of the main scanning direction and the sub-scanning direction. The Therefore, the scanning speed Vsp of the spot light SP in the main scanning direction and the oscillation frequency Fa are set so as to have a relationship of Vsp = (φ / 2) / Tf = (φ / 2) · Fa. On the other hand, the scanning speed Vsp includes the rotational speed VR (rpm) of the polygon mirror PM, the effective scanning length LT, the number Np (= 8) of the reflecting surfaces of the polygon mirror PM, and one reflecting surface of the polygon mirror PM. Based on the scanning efficiency 1 / α by RP, it is determined as follows.
Vsp = (8 · α · VR · LT) / 60 [mm / sec]
Therefore, the oscillation frequency Fa (cycle Tf) and the rotation speed VR (rpm) are set to satisfy the following relationship.
(Φ / 2) / Tf = (8 · α · VR · LT) / 60 Formula A

  When the oscillation frequency Fa is 400 MHz (Tf = 2.5 nS) and the diameter φ of the spot light SP is 4 μm, the scanning speed Vsp defined by the oscillation frequency Fa is 0.8 μm / nS (= 2 μm / 2.5 nS). It becomes. In order to correspond to this scanning speed Vsp, when the scanning efficiency 1 / α is 0.3 (α≈3.33) and the scanning length LT is 50 mm, the relationship between the formula A and the 8-sided polygon mirror PM The rotation speed VR may be set to 36000 rpm. In this case, the scanning speed Vsp = 0.8 μm / nS is 2880 Km / h in terms of hourly speed.

  In the beam receiving system 60b constituting the origin sensor shown in FIG. 2, the rotational position of the reflection surface RP of the polygon mirror PM is just before the scanning of the spot light SP of the drawing beam LBn by the reflection surface RP can be started. An origin signal SZn having a waveform change is generated at the moment when it reaches a predetermined position (specified angle position, origin angle position). Since the polygon mirror PM has eight reflecting surfaces RP, the beam receiving system 60b outputs eight origin signals SZn during one rotation of the polygon mirror PM. The origin signal SZn is sent to the drawing control apparatus 200 (see FIG. 4), and scanning of the spot light SP along the drawing line SLn is started after a predetermined delay time Tdn has elapsed since the origin signal SZn is generated. The

  FIG. 3 is a diagram showing a specific configuration around the optical element for selection OSn (OS1 to OS6) and the incident mirror IMn (IM1 to IM6). The beam LB emitted from the light source device LS is incident on the selection optical element OSn as a parallel light beam having a minute diameter (first diameter) of 1 mm or less, for example. In a period when the drive signal DFn, which is a high-frequency signal (ultrasonic signal), is not input (the drive signal DFn is off), the incident beam LB is transmitted without being diffracted by the selection optical element OSn. The transmitted beam LB passes through the condensing lens Ga and the collimating lens Gb provided on the optical path along the optical axis AXb, and enters the selection optical element OSn at the subsequent stage. At this time, the beam LB passing through the condenser lens Ga and the collimator lens Gb through the selection optical element OSn is coaxial with the optical axis AXb. The condensing lens Ga condenses the beam LB (parallel light beam) transmitted through the selection optical element OSn so as to be a beam waist at the position of the surface Ps located between the condensing lens Ga and the collimating lens Gb. . The collimating lens Gb turns the beam LB diverging from the position of the surface Ps into a parallel light beam. The diameter of the beam LB converted into a parallel light beam by the collimating lens Gb is the first diameter. The rear focal position of the condensing lens Ga and the front focal position of the collimating lens Gb coincide with the surface Ps within a predetermined allowable range, and the front focal position of the condensing lens Ga is within the selection optical element OSn. It arrange | positions so that it may correspond within a predetermined tolerance with a diffraction point.

  On the other hand, during the ON period in which the drive signal DFn, which is a high-frequency signal, is applied to the selection optical element OSn, the incident beam LB is diffracted with the beam LBn (first-order diffracted light) diffracted by the selection optical element OSn. The zeroth-order beam LBnz that has not occurred is generated. When the intensity of the incident beam LB is 100% and the decrease due to the transmittance of the optical element for selection OSn is ignored, the intensity of the diffracted beam LBn is about 80% at the maximum, and the remaining 20% is the 0th order. It becomes the intensity of the beam LBnz. The 0th-order beam LBnz passes through the condensing lens Ga and the collimating lens Gb, passes through the subsequent selection optical element OSn, and is absorbed by the absorber TR. The beam LBn (parallel light beam) deflected in the −Z direction at a diffraction angle corresponding to the high frequency of the drive signal DFn passes through the condenser lens Ga and travels toward the incident mirror IMn provided on the surface Ps. Since the front focal position of the condensing lens Ga is optically conjugate with the diffraction point in the optical element for selection OSn, the beam LBn from the condensing lens Ga toward the incident mirror IMn has a position decentered from the optical axis AXb. The light travels in parallel with the axis AXb and is condensed (converged) so as to be a beam waist at the position of the surface Ps. The position of the beam waist is set so as to be optically conjugate with the spot light SP projected onto the substrate P through the drawing unit Un.

  By disposing the reflective surface of the incident mirror IMn or its vicinity at the position of the surface Ps, the beam LBn deflected (diffracted) by the selection optical element OSn is reflected in the −Z direction by the incident mirror IMn, and collimated lens Gc. And enters the drawing unit Un along the optical axis AX1 (see FIGS. 2 and 3). The collimating lens Gc turns the beam LBn converged / diverged by the condenser lens Ga into a parallel light beam coaxial with the optical axis (AX1) of the collimating lens Gc. The diameter of the beam LBn made into a parallel light beam by the collimating lens Gc is substantially the same as the first diameter. The rear focal point of the condensing lens Ga and the front focal point of the collimating lens Gc are arranged on or near the reflecting surface of the incident mirror IMn within a predetermined allowable range.

  As described above, the front focal position of the condenser lens Ga and the diffraction point in the optical element for selection OSn are optically conjugated, and the incident mirror IMn is disposed on the surface Ps that is the rear focal position of the condenser lens Ga. Then, by changing the frequency of the drive signal DFn of the selection optical element OSn by ± ΔFs from the specified frequency, the amount of eccentricity (shift amount) of the condensing point on the surface Ps of the beam LBn with respect to the optical axis AXb is changed. be able to. As a result, the spot light SP of the beam LBn projected from the drawing unit Un onto the substrate P can be shifted by ± ΔSFp in the sub-scanning direction. The shift amount (| ΔSFp |) is the maximum range of the deflection angle of the optical element for selection OSn itself, the size of the reflecting surface of the incident mirror IMn, and the optical system (relay system) up to the polygon mirror PM in the drawing unit Un. Although it is limited by the magnification, the width in the Z direction of the reflecting surface RP of the polygon mirror PM, the magnification from the polygon mirror PM to the substrate P (magnification of the fθ lens system FT), etc., the effective spot light SP on the substrate P is limited. Adjustment is possible within the range of the size (diameter) or the pixel size (Pxy) defined on the drawing data. Accordingly, an overlay error between a new pattern drawn on the substrate P in each drawing unit Un and a pattern formed on the substrate P, or a new pattern drawn on the substrate P in each drawing unit Un. It is possible to correct a joint error between various patterns with high accuracy and at high speed.

  FIG. 4 is a schematic diagram of a beam switching unit including a selection optical element OSn (OS1 to OS6) for selectively distributing the beam LB from the light source device LS to any one of the six drawing units U1 to U6. The configuration is shown. 4 are the same as those shown in FIG. 1, but the reflection mirrors M1 to M12 shown in FIG. 1 are omitted as appropriate. A light source device LS composed of a fiber amplifier laser light source is connected to the drawing control device 200 and exchanges various control information SJ. The light source device LS includes a clock circuit that generates a clock signal CLK having an oscillation frequency Fa (for example, 400 MHz) when causing the beam LB to emit pulses, and performs drawing for each drawing unit Un sent from the drawing control device 200. Based on the data SDn (serial data from bitmap data in which one pixel is one bit), the beam LBn is transmitted in response to the clock signal CLK in burst mode (emission for a predetermined number of clock pulses and a predetermined number of clock pulses). Pulse light emission). As described above, in the present embodiment, the light source device LS itself modulates the intensity of the beam LB for pattern drawing (switching on / off of pulsed light emission).

  The drawing control apparatus 200 receives the origin signal SZn (SZ1 to SZ6) output from the beam receiving unit (beam receiving system, light receiving system) 60b of each origin sensor of the drawing units U1 to U6, and receives the drawing units U1 to U1. A polygon rotation control unit that controls the rotation motor RM of the polygon mirror PM and a selection optical element OSn (OS1 to OS6) so that the rotation speed and rotation angle phase of each polygon mirror PM of U6 are designated. ) Are switched on / off (applied / non-applied) as drive signals DF1 to DF6 as ultrasonic signals based on the origin signals SZn (SZ1 to SZ6) (later FIG. 5). Will be described in detail). In FIG. 4, it is assumed that the beam LB from the light source device LS passes through the optical element for selection OS5 → OS6 → OS3 → OS4 → OS1 → OS2 in accordance with the arrangement of FIG. In FIG. 4, the selection optical element OS4 out of the six selection optical elements OS1 to OS6 is selected and turned on, and the beam LB from the light source device LS (the drawing data SDn of the pattern drawn by the drawing unit U4) Is modulated toward the incident mirror IM4 and is supplied to the drawing unit U4 as a beam LB4.

  As described above, when the selection optical elements OS1 to OS6 are provided in series on the optical path of the beam LB, the order of the selection optical elements OSn from the light source device LS depends on the transmittance and diffraction efficiency of each of the selection optical elements OSn. Depending on the intensity of the selected beams LB1 to LB6 (the peak intensity of the pulsed light) varies. Therefore, the relative difference in the intensity of the beams LB1 to LB6 incident on each of the drawing units U1 to U6 (that is, the exposure amount that each of the drawing units U1 to U6 gives to the photosensitive layer of the substrate P) falls within a predetermined allowable range ( For example, it is necessary to adjust (align) within ± 5%, preferably within ± 2%. In the present embodiment, the intensity of each of the beams LB1 to LB6 incident on each of the drawing units U1 to U6 is set to the level of each of the drive signals DF1 to DF6 (high frequency signal) for driving each of the selection optical elements OS1 to OS6. The amplitude or power) is changed and adjusted.

  For this purpose, in the present embodiment, as shown in FIG. 4, photoelectric sensors DTa, DTb, and DT1 to DT6 for detecting the beam intensity are provided at several locations in the optical path through which the beam LB from the light source device LS passes. The intensity of each of the beams LB1 to LB6 supplied to each of the drawing units U1 to U6 is monitored. 4, the photoelectric sensor DTa (first photoelectric sensor) transmits a beam LB emitted from the light source device LS at a constant rate (for example, several% or less) when the beam LB is reflected by the reflection mirror M1 in FIG. The incoming leakage light is received and a photoelectric signal corresponding to the intensity is output. The photoelectric signal from the photoelectric sensor DTa is input to a detection circuit CKa including an amplifier, a sample hold circuit, an analog / digital converter, and the detection circuit CKa outputs a detection signal Sa corresponding to the intensity of the beam LB from the light source device LS. Output. Note that when the light source device LS includes a wavelength conversion element, a long wavelength region beam before wavelength conversion may be output superimposed on the ultraviolet wavelength region beam LB, so that the long wavelength is output to the emission window of the light source device LS. It is preferable to provide a wavelength filter that blocks the beam in the region and transmits the beam LB in the ultraviolet wavelength region.

  The photoelectric sensor DTb (second photoelectric sensor) is in front of the absorber TR that is incident after the beam LB from the light source device LS sequentially passes through the six selection optical elements OS5, OS6, OS3, OS4, OS1, and OS2. The beam (0th-order light) transmitted through the partial reflection mirror Mb disposed at the position is received. The partial reflection mirror Mb amplitude-divides the beam (zero-order light) that has passed through the final selection optical element OS2 out of the six selection optical elements OS1 to OS6 into the absorber TR and the photoelectric sensor DTb. Functions as a splitter. The photoelectric signal output from the photoelectric sensor DTb is input to a detection circuit CKb including an amplifier, a sample-and-hold circuit, an analog / digital converter, and the like. The detection circuit CKb passes through the final-stage selection optical element OS2 ( A detection signal Sb corresponding to the intensity of the 0th order light is output. Here, the detection signals Sa and Sb output from the detection circuits CKa and CKb are adjusted (calibrated) so as to have the same value when the intensities of the beams received by the photoelectric sensors DTa and DTb are the same. It shall be.

  Furthermore, in the present embodiment, on the back side of the reflecting mirror M22 that reflects the beams LBn (LB1 to LB6) reflected by the incident mirrors IMn (IM1 to IM6) and incident on the drawing units Un (U1 to U6). Photoelectric sensors DT1 to DT6 that are arranged and receive the leakage light of the beam LBn at the reflection mirror M22 are provided. The reflecting surface of the reflecting mirror M22 reflects most of the incident beam LBn (for example, about 98%), but the remaining intensity is transmitted as leakage light. Although not shown in FIG. 4, photoelectric signals Sm1 to Sm6 from the photoelectric sensors DT1 to DT6 are amplified by detection circuits similar to the detection circuits CKa and CKb, respectively, and correspond to the intensities of the photoelectric signals Sm1 to Sm6. The measured signal (digital value) is generated. In actual exposure control, those measurement signals are used. Here, for simplicity of explanation, the exposure control is performed based on the intensity of each of the photoelectric signals Sm1 to Sm6. Each intensity of the photoelectric signals Sm1 to Sm6 (measurement signals after amplification) corresponds to the absolute intensity of the spot light SP (beams LB1 to LB6) projected onto the substrate P by each of the drawing units U1 to U6. The amplification factor in the detection circuit is calibrated in advance. Therefore, if exposure control (intensity correction) is performed so that the intensity of each of the photoelectric signals Sm1 to Sm6 is within a predetermined allowable range (for example, within ± 2%), the pattern drawn by each of the drawing units U1 to U6 is The exposure is performed with the same exposure amount (dose amount).

  FIG. 5 is provided in the drawing control apparatus 200 of FIG. 4, and includes an intensity adjustment control unit 250 for controlling the exposure amount in each of the drawing units Un, and driving signals of the selection optical elements OS1 to OS6. The structure with the drive circuits 251a-251f which generate | occur | produce DF1-DF6 is shown. The intensity adjustment control unit 250 inputs the photoelectric signals Sm1 to Sm6 (measurement signals after amplification) shown in FIG. 4 and the detection signals Sa and Sb from the detection circuits CKa and CKb and Various control information IFD is exchanged with the main control CPU. Each of the drive circuits 251a to 251f receives a high frequency signal from the oscillation circuit RF, and the drive signal DF1 adjusted to an amplitude (power) according to the adjustment signals Pw1 to Pw6 from each of the gain adjustment circuits 252a to 252f. ~ DF6 is output. The intensity adjustment control unit (beam intensity measurement unit) 250 changes the adjustment signals Pw1 to Pw6 to each of the gain adjustment circuits 252a to 252f based on the photoelectric signals Sm1 to Sm6, the detection signals Sa and Sb, and the control information IFD. Command information (digital target value) is calculated and sent out by calculation. In the present embodiment, the intensity adjustment control unit 250 adjusts the intensity of each of the beams LB1 to LB6 so that the exposure amount in each of the drawing units Un is aligned with the target value indicated by the control information IFD.

  Further, in response to each of the origin signals SZ1 to SZ6, the intensity adjustment control unit 250 scans each of the selection optical elements OS1 to OS6 for a predetermined time (a period during which one reflecting surface of the polygon mirror PM scans the beam LBn). Switching signals LP1 to LP6 that are switched to the off state after the on state are output to the drive circuits 251a to 251f. Each of the drive circuits 251a to 251f switches between application states and non-application states of the drive signals DF1 to DF6 to the selection optical elements OS1 to OS6 in response to the switching signals LP1 to LP6.

  FIG. 6 is a diagram illustrating an example of a change characteristic CCa of diffraction efficiency due to a change in the RF power (amplitude of the high-frequency signal) of the drive signal DFn applied to the acousto-optic modulator as the selection optical element OSn. In FIG. 6, the horizontal axis represents the RF power of the drive signal DFn, and the vertical axis represents the diffraction efficiency (ratio of the intensity of the deflected beam LBn to the intensity of the incident beam LB) β. The diffraction efficiency β increases as the RF power input within the adjustable range ΔKn increases, and gradually decreases after reaching the maximum diffraction efficiency (upper limit of the adjustable range ΔKn) at a certain power value Pwm. Have a tendency. The maximum efficiency is 80% or less, although there are some changes depending on the type of crystal medium of the acousto-optic modulator. The lower limit of the adjustable range ΔKn of the efficiency β can be widened to a relatively low value, and the power value corresponding to the lower limit is Pwo. In FIG. 3 described above, the intensity of the beam LB incident on the selection optical element OSn is Eo (100%), the efficiency of the selection optical element OSn is βn (%), and the transmittance is εn (%). At this time, the intensity Ed of the beam LBn deflected by the selection optical element OSn is represented by Ed = εn · βn · Eo, and the intensity Es of the beam LBnz (non-deflected zero-order light) transmitted without being deflected is Es = εn · (1−βn) · Eo. The change characteristic CCa of the efficiency β changes when the incident angle of the beam LB incident on the selection optical element OSn slightly fluctuates or when the temperature of the crystal medium (or quartz) of the selection optical element OSn changes greatly. Therefore, even if the same RF power is applied to the selection optical element OSn, the efficiency is not the same, and the intensity of the deflected beam LBn varies. The transmittance εn is determined by the absorption characteristics of the incident beam LB in the crystal medium (or quartz), the characteristics of the antireflection film coated on the incident surface and the exit surface, etc., and is usually a constant value that does not vary (for example, 95%). However, when the beam in the ultraviolet wavelength region is passed for a long time, the transmittance εn may gradually change (decrease) due to deterioration or the like.

  In the present embodiment, the values of the photoelectric signals Sm1 to Sm6 corresponding to the intensities of the beams LB1 to LB6 measured by the photoelectric sensors DT1 to DT6 shown in FIG. 4 are set corresponding to the appropriate exposure amount. For example, during the pattern exposure operation, the intensity adjustment control unit 250 adjusts (corrects) the supply power (amplitude) of each of the drive signals DF1 to DF6 with feedback so that the target value can be suppressed within ± 2%, for example. be able to. However, when it is necessary to change the appropriate exposure amount, the intensity β of each of the deflected beams LBn is adjusted by changing the efficiency β of the optical element for selection OSn. However, such adjustment is limited. There is. This will be described with reference to FIG.

  FIG. 7 shows the intensities of the beams LB1 to LB6 supplied to the drawing units U1 to U6 and the adjustable ranges ΔK1 to ΔK6 of the selection optical elements OS1 to OS6 for adjusting the intensities of the beams LB1 to LB6. It is the graph shown typically. In FIG. 7, the horizontal axis indicates the intensity and the adjustable range of the beam LBn in each of the drawing units U5, U6, U3, U4, U1, and U2 from the left side in accordance with the order in which the beam LB from the light source device LS is supplied. ΔKn (ΔK1 to ΔK6) are arranged. As shown in FIG. 4 (FIG. 1), when the six selection optical elements OS1 to OS6 are serially arranged along the optical path of the beam LB, the degree of the transmittance εn of the selection optical elements OS1 to OS6 and individual transmissions. The adjustment state of the efficiency βn by each of the selection optical elements OS1 to OS6 varies depending on the difference in the rate εn.

  For example, the intensity E5 (value measured by the photoelectric sensor DT5) of the beam LB5 deflected by the foremost selection optical element OS5 closest to the light source device LS is the intensity of the beam LB when the light source device LS is emitted. Assuming Eo (value measured by the photoelectric sensor DTa), E5 = ε5 · β5 · Eo is represented by the transmittance ε5 and the efficiency β5 of the optical element for selection OS5. On the other hand, the intensity E2 of the beam LB2 deflected by the last-stage selection optical element OS2 farthest from the light source device LS is the product of all the transmittances εn of the six selection optical elements OS1 to OS6 and the efficiency. By β2, E2 = ε5 · ε6 · ε3 · ε4 · ε1 · ε2 · β2 · Eo. Assuming that the transmittances εn of the six selection optical elements OS1 to OS6 are the same and 95%, the intensity E5 of the beam LB5 is E5 = 0.95 · β5 · Eo, and the intensity E2 of the beam LB2 is E2 = 0.735 · β2 · Eo. In order to set the intensity E5 of the beam LB5 and the intensity E2 of the beam LB2 equal, the efficiency β5 of the selection optical element OS5 is set low, and the efficiency β2 of the selection optical element OS2 is set high.

  Setting the efficiency β5 of the selection optical element OS5 low means lowering the power value on the efficiency change characteristic CCa shown in FIG. 6, and setting the efficiency β2 of the selection optical element OS2 high. That is to increase the power value. In the case of the setting shown in FIG. 7, when the intensity of each of the beams LB1 to LB6 is set within an allowable range (for example, ± 2%) with respect to the target value, the efficiency of the selection optical element OS5 at the foremost stage is set. β5 is set below the efficiency (power) adjustable range ΔK5, and the efficiency β2 of the final stage selection optical element OS2 is set above the efficiency (power) adjustable range ΔK2. In the case of FIG. 7, the last-stage selection optical element OS2 is approaching the upper limit (corresponding to the power value Pwm) of the adjustable range ΔK2, and the foremost selection optical element OS5 is the lower limit (power) of the adjustable range ΔK5. (Corresponding to the value Pwo). Therefore, in FIG. 7, when changing the target value of the intensity of the beams LB1 to LB6, the upper limit of the efficiency adjustable range ΔK2 of the selection optical element OS2 and the efficiency adjustable range ΔK5 of the selection optical element OS5 The intensity (exposure amount) between the lower limit and the settable range is limited.

  In an actual apparatus, the beam LB from the light source device LS is adjusted so that the intensity of the beam LB2 deflected by the last-stage selection optical element OS2 that receives the most attenuation becomes an appropriate exposure amount with respect to the photosensitive layer of the substrate P. The maximum strength (power) is set with some margin. Therefore, when adjusting the appropriate exposure amount due to the difference in the sensitivity of the photosensitive layer of the substrate P and the difference in the thickness of the photosensitive layer, can the target value of the intensity be changed within the intensity (exposure amount) settable range of FIG. No is determined by the drawing control device 200 or the intensity adjustment control unit 250. When the new target values of the intensities of the beams LB1 to LB6 corresponding to the appropriate exposure amount to be adjusted are within the intensity (exposure amount) settable range in FIG. 7, the efficiency βn of each of the optical elements for selection OS1 to OS6 Is corrected from the current value, the RF power of each of the drive signals DF1 to DF6 is corrected based on the efficiency change characteristic CCa of FIG.

  If the new target value of the intensity of the beams LB1 to LB6 corresponding to the appropriate exposure amount to be adjusted falls outside the intensity (exposure amount) settable range in FIG. The exposure amount by the beam LB2 (drawing unit U2) deflected by the stage selection optical element OS2 will be insufficient, and if the target value falls below the intensity (exposure amount) settable range in FIG. Even if the adjustment (correction) is performed, the exposure amount by the beam LB5 (drawing unit U5) deflected by the selection optical element OS5 at the foremost stage is over. In the case where a plurality of optical elements for selection OSn are arranged in series along the optical path of the beam LB from the light source device LS as in the present embodiment, the variation of the members inside the light source device LS causes deterioration and deterioration of the beam LB. When the intensity gradually decreases, in order to maintain the intensity of each beam LBn at the target value, the efficiency βn of each optical element for selection OSn is increased. For this reason, the adjustable range ΔKn of the efficiency βn of each of the selection optical elements OSn shown in FIG. 7 is shifted downward relative to the target value. In this case, if the efficiency βn and the transmittance εn of each of the selection optical elements OSn are the same, the adjustable range ΔK2 of the efficiency β2 of the selection optical element OS2 located at the final stage first reaches the upper limit. No further adjustments can be made.

  Therefore, in the present embodiment, the drawing control device 200 or the intensity adjustment control unit 250 sequentially monitors the intensity change of the beam LB emitted from the light source device LS based on the detection signal Sa from the detection circuit CKa shown in FIG. In particular, the efficiency β2 of the selection optical element OS2 located at the last stage among the selection optical elements OSn so that the appropriate exposure amount (target value in FIG. 7) is maintained regardless of the intensity change. It is confirmed whether or not (RF power) can be changed within the adjustable range ΔK2. When possible, the RF power (amplitude) of each of the drive signals DFn is controlled by the intensity adjustment control unit 250 so that the efficiency βn of all the selection optical elements OSn including the selection optical element OS2 is adjusted. . As described above, the relationship between the efficiency β2 (RF power) in the final selection optical element OS2 and the adjustable range ΔK2 is determined by the efficiency βn and the transmittance εn of all the selection optical elements OSn. This is because it is assumed that they are the same. As in the first embodiment, the efficiency βn and the transmittance εn are measured, and the fluctuation of the efficiency βn and the variation of the transmittance εn tend to deviate from the allowable range. The selection optical element OSn is specified, the relationship between the efficiency βn (RF power) in the selection optical element OSn and the adjustable range ΔKn is confirmed, and the intensity of the beam LBn by each of the drawing units Un is matched. Adjust it.

  As described above, in the present embodiment, the beam LB is generated by each of the plurality of selection optical elements (acousto-optic modulation elements) OSn provided so that the beams LB emitted from the light source device LS are sequentially passed. When selectively supplying to any of the corresponding drawing units Un, even if the intensity of the beam LB from the light source device LS decreases, the adjustable range of each efficiency (change in beam intensity) of the optical element for selection OSn. Since each intensity of the beam LBn supplied to each of the drawing units Un is adjusted under ΔKn, the pattern drawn by each of the drawing units Un has the same exposure amount (for example, within an allowable range of ± 2%). Exposed. For this reason, the uniformity of the line width at the joint portion of the pattern exposed in each of the drawing units Un is maintained.

[Second Embodiment]
In the above embodiment, paying attention to the adjustable range ΔK2 of the efficiency β2 (RF power) in the selection optical element OS2 located in the final stage among the selection optical elements OSn, each drawing unit Un It was determined whether or not the pattern drawing was aligned so as to have an appropriate exposure amount. However, when the efficiency βn of each of the selection optical elements OSn is relatively different, just pay attention to the adjustable range ΔK2 of the efficiency β2 (RF power) of the last-stage selection optical element OS2 as shown in FIG. Instead, it is desirable to determine whether or not the designated appropriate exposure amount (target value of the intensity of the beam LBn) can be obtained from the adjustable range ΔKn of the efficiency βn of all the optical elements for selection OSn. For this purpose, it is necessary to grasp the state of variation of the efficiency βn of each of the selection optical elements OSn at an appropriate time interval and reset the adjustable range ΔKn. Therefore, in this embodiment, the variation of the efficiency βn of each optical element for selection OSn is measured using the detection signals Sa and Sb from the photoelectric sensors DTa and DTb shown in FIG.

FIG. 8 shows that among the six selection optical elements OS1 to OS6 arranged in series along the traveling direction of the beam LB from the light source device LS, the third selection optical element OS3 is turned on, and the other 5 It is a figure which shows typically the generation | occurrence | production state of each beam when the two optical elements for selection OS5, OS6, OS4, OS1, and OS2 are turned off. In FIG. 8, since the optical element for selection OS3 is in the ON state, the beam LB3z as the zero-order light traveling in the non-deflected state by the optical element for selection OS3 is received by the photoelectric sensor DTb and output as the detection signal Sb. Is done. Here, Ea is the intensity of the detection signal Sa corresponding to the intensity of the beam LB received by the photoelectric sensor DTa, and light is received by the photoelectric sensor DTb when all the selection optical elements OSn (OS1 to OS6) are in the OFF state. Assuming that the intensity of the detection signal Sb corresponding to the intensity of the 0th-order light of the beam LB is Eb0, the intensity Eb0 is expressed by the following equation 1 by the transmittance εn.
Eb0 = ε5 · ε6 · ε3 · ε4 · ε1 · ε2 · Ea (1)
Here, the product of the six transmittances ε1 to ε6 is defined as Kε. Note that in order to obtain the intensity Ea and the intensity Eb0, the drawing control apparatus 200 uses the beam LB when all the selection optical elements OSn are in an off state, that is, during a period when all the drawing units Un do not perform pattern drawing. Causes the light source device LS to emit light for a short time so that each of the optical elements OSn for selection passes through.

Next, the intensity Eb5 of the detection signal Sb corresponding to the intensity of the 0th-order light received by the photoelectric sensor DTb when only the foremost selection optical element OS5 is in the ON state is the value of the selection optical element OS5. The efficiency β5 is entered, and is expressed by the following formula 2.
Eb5 = Kε (1-β5) Ea (2)

Similarly, the intensities Eb6 and Eb3 of the detection signals Sb corresponding to the intensities of the zeroth order light received by the photoelectric sensor DTb when the selection optical elements OS6, OS3, OS4, OS1, and OS2 are sequentially turned on. , Eb4, Eb1, and Eb2 are represented by the following formulas 3 to 7, respectively.
Eb6 = Kε (1-β6) Ea (3)
Eb3 = Kε (1-β3) Ea (4)
Eb4 = Kε (1-β4) Ea (5)
Eb1 = Kε (1-β1) Ea (6)
Eb2 = Kε (1-β2) Ea (7)

From the above formulas 1 to 7, the intensity adjustment control unit 250 having the function of the beam intensity measurement unit calculates the intensity Ea corresponding to the beam LB received by the photoelectric sensor DTa and the zero-order light received by the photoelectric sensor DTb. Based on the intensity Ebn (Eb1 to Eb6) corresponding to the beam LBnz, each efficiency βn of the optical element for selection OSn at the time of measurement (during the pattern exposure operation) is obtained by the following equation (8).
βn = 1− (Ebn / Eb0) (8)

Further, during the pattern exposure operation, the respective intensities (corresponding to the magnitudes of the photoelectric signals Sm1 to Sm6) of the deflected beams LB1 to LB6 detected by the photoelectric sensors DT1 to DT6 shown in FIG. Then, based on the measured efficiency βn, the transmittance ε5 of the foremost selection optical element OS5 is Es5 = ε5 · β5 · Ea,
ε5 = Es5 / (β5 · Ea) (9)
It becomes.

The transmittance ε6 of the selection stage optical element OS6 is Es6 = ε6 · ε5 · β6 · Ea:
ε6 = Es6 / (ε5 · β6 · Ea) (10)
It becomes.

Since the transmittance ε5 is obtained by Equation 9, if this is substituted into Equation 10, the transmittance ε6 is
ε6 = (β5 · Es6) / (β6 · Es5) (11)
It becomes.

Further, the transmittance ε3 of the selection optical element OS3 in the next stage is Es3 = ε3 · ε6 · ε5 · β3 · Ea,
ε3 = Es3 / (ε6 · ε5 · β3 · Ea) (12)
It becomes.

Since the transmittances ε5 and ε6 are obtained by the equations 9 and 11, ε6 · ε5 is ε6 · ε5 = Es6 / (β6 · Ea). When this is substituted into the equation 12, the transmittance ε3 is
ε3 = (β6 · Es3) / (β3 · Es6) (13)
It becomes.

Similarly, the transmittance ε4 of the selection optical element OS4, the transmittance ε1 of the selection optical element OS1, and the transmittance ε2 of the selection optical element OS2 are respectively
Es4 = ε4 · ε3 · ε5 · ε6 · β4 · Ea,
Es1 = ε1, ε4, ε3, ε5, ε6, β1, Ea,
Es2 = ε2, ε1, ε4, ε3, ε5, ε6, β2, Ea,
From the relationship
ε4 = (β3 · Es4) / (β4 · Es3) (14)
ε1 = (β4 · Es1) / (β1 · Es4) (15)
ε2 = (β1 · Es2) / (β2 · Es1) (16)
It becomes.

  In order to accurately perform such calculations, the measured values of the signals measured by the photoelectric sensors DTa, DTb, and DT1 to DT6 are preliminarily set so as to accurately correspond to the absolute value of the intensity of the received light beam. It is assumed that it has been calibrated.

  While the intensity of the beam LBn from each of the drawing units Un is adjusted so as to be an appropriate exposure amount and pattern exposure is performed, the efficiency βn of each of the six selection optical elements OSn is set as described above. When the transmittance εn is sequentially measured at an appropriate interval, for example, every exposure time on the exposure area on the substrate P, it is possible to identify the drawing unit Un whose exposure amount may vary, The intensity adjustment control unit 250 shown in FIG. 5 can adjust the drive signal DFn of the selection optical element OSn corresponding to the drawing unit Un so that the variation is corrected. In the present embodiment, in addition to the photoelectric sensor DTa that detects the intensity of the beam LB emitted from the light source device LS, the zero-order light beam of the beam LB that passes through the six selection optical elements OS1 to OS6. By providing the beam intensity measuring unit by the photoelectric sensor DTb for detecting the intensity and the detection circuit CKb, the current efficiencies β1 to β6 of the selection optical elements OS1 to OS6 and their variations can be easily measured. Therefore, the efficiency βn varies depending on the refractive index variation due to the thermal influence of each of the selection optical elements OS1 to OS6, the slight inclination of the beam optical path due to the variation of other optical elements (condensing lens and collimator lens), and the like. The selected optical element OSn can be specified. Further, the adjustable range ΔKn shown in FIG. 7 for correcting the intensity of the beam LBn can be confirmed and reset from the measured variation in the efficiency βn.

  Further, when the photoelectric sensors DT1 to DT6 that are provided in each of the drawing units U1 to U6 and detect the intensities of the beams LB1 to LB6 deflected by the selection optical elements OS1 to OS6 are used, the selection optical elements OS1 to OS1 are used. Since each of the transmittances ε1 to ε6 of OS6 and its fluctuations can be easily measured, the pattern drawn by each of the drawing units U1 to U6 can be accurately exposed and maintained at an appropriate exposure amount. Further, according to the present embodiment, even if the intensity Ea of the beam LB from the light source device LS measured by the photoelectric sensor DTa changes, the efficiency βn and the transmittance εn of each optical element OSn for selection are obtained. Therefore, without using each of the photoelectric sensors DT1 to DT6 provided in the drawing unit Un, the intensity of the beam LBn supplied to each of the drawing units Un can be adjusted by the drawing control device 200 or the intensity adjustment control unit 250. It is possible to calculate (measure) with high accuracy.

[Modification 1]
In each of the above embodiments, each of the plurality of selection optical elements OSn is an acousto-optic modulation element (AOM), and the beam LBn is deflected to each of the drawing units Un by the diffraction effect. The beam LBn may be deflected using a splitter (polarization separation element). The electro-optic element has a chemical composition of KDP (KH ₂ PO ₄ ), ADP (NH ₄ H ₂ PO ₄ ), KD * P (KD ₂ PO ₄ ), KDA (KH ₂ AsO ₄ ), BaTiO ₃ , SrTiO _3. , LiNbO ₃ , LiTaO _{3 and the} like. The electro-optic element rotates the polarization direction of an incident linearly polarized beam by 90 ° with the refractive index changed by an applied electric field. Therefore, when the beam emitted from the electro-optic element is incident on the deflecting beam splitter, it can be switched at high speed between a state of reflecting toward the drawing unit Un and a state of non-deflecting transmission according to the polarization direction. In the case of this modification, when the beam from the electro-optical element is reflected toward the drawing unit Un by the deflecting beam splitter, the leakage light transmitted through the deflecting beam splitter is transmitted to each of the selection optical elements OSn in the subsequent stage. Since the light is transmitted through the electro-optic element and the polarization beam splitter, it can be similarly detected by the photoelectric sensor DTb as shown in FIG. However, in order to secure the intensity of the leaked light, the polarization direction of the linearly polarized beam incident on the electro-optic element is not exactly rotated by 90 degrees with the electro-optic element, but is intentionally slightly shifted from 90 degrees. Thus, the electric field to be applied may be set.

[Modification 2]
In each of the above embodiments, the switching selection optical element OSn that selectively supplies the beam LB from the light source device LS to any one of the plurality of drawing units Un is provided in the drawing unit Un. Although used for adjusting the intensity of the beam LBn toward each, the switching function and the intensity adjusting function may be realized by separate optical members. For example, the selection optical element OSn of the above embodiment may be used only for switching, and may be a polarization adjustment member that controls the polarization state of the beam LBn and corrects the beam intensity separately for intensity adjustment. As a polarization adjusting member, an electro-optical element (an element that changes the polarization direction by the Pockels effect or Kerr effect whose refractive index changes by an electric field) that receives a linearly polarized beam, and polarization in a predetermined direction from the beam emitted from the electro-optical element A combination with a polarizing plate that transmits the component can be used. Such a polarization adjusting member may be provided inside each drawing unit Un, or only one may be provided between the light source device LS and the foremost selection optical element OS5.

[Modification 3]
Further, in the case where the intensity adjusting member is provided individually, the reflection mirror M20 and the reflection mirror in the drawing unit Un of FIG. 2 if the variation of the efficiency βn and the transmittance εn of each of the switching selection optical elements OSn is moderate. A glass plate (variable ND filter) provided with a concentration distribution so that the transmittance gradually changes is provided in the optical path of the beam LBn expanded by a beam expander (not shown) provided between M20a, and the glass plate The intensity may be adjusted by moving the glass plate so that the transmission position of the beam LBn is shifted.

[Other variations]
In each of the above embodiments, the beam LB from one light source device LS is selectively supplied to any one of the six drawing units U1 to U6. However, the scanning efficiency of the polygon mirror PM is 1 Depending on / α, two light source devices LS are provided, and a beam LB from one light source device LS is selectively supplied to any one of, for example, three odd-numbered drawing units U1, U3, and U5. The beam LB from the other light source device LS may be controlled to be selectively supplied to any one of the even-numbered three drawing units U2, U4, U6. In addition, the number of drawing units that supply the beam LB from one light source device LS by switching in a time division manner is not limited to six or three, and may be two or more. In addition, the drawing unit of each embodiment performs beam scanning using the rotating polygon mirror PM. Instead, the galvanometer mirror (scanning member) that reciprocally vibrates around the rotation axis APx within a certain angular range. May be used to scan the beam LBn incident on the fθ lens system FT.

Claims (20)

A pattern drawing device that draws a pattern on the substrate by a plurality of drawing units that draw a pattern by scanning the beam from the light source device on the substrate with a scanning member,
In order to selectively supply the beam from the light source device to any one of the plurality of drawing units, the beam from the light source device is arranged to pass through in order, and the beam is controlled by electrical control. A beam switching unit having a plurality of optical members for selection directed to the drawing unit;
When adjusting the intensity of the beam projected from the specific drawing unit of the plurality of drawing units onto the substrate, the beam is projected onto the substrate within an adjustable range of the beam intensity adjustment unit corresponding to the specific drawing unit. The intensity of the beam projected onto the substrate from each of the other drawing units other than the specific drawing unit, and the intensity of the beam projected onto the substrate from the specific drawing unit. A control unit for controlling the beam intensity adjustment unit corresponding to each of the other drawing units,
A pattern drawing apparatus. The pattern drawing apparatus according to claim 1,
The pattern drawing apparatus, wherein the selection optical member is an acousto-optic modulation element that deflects a beam from the light source device toward the drawing unit by a diffraction action. The pattern drawing apparatus according to claim 2,
The pattern drawing apparatus, wherein the beam intensity adjusting unit includes a drive circuit that adjusts a drive signal of the acousto-optic modulation element so as to adjust the efficiency of the acousto-optic modulation element as the selection optical member. It is a pattern drawing apparatus of Claim 3, Comprising:
The control unit compares the adjustable range of the efficiency of the acousto-optic modulator that constitutes each of the plurality of optical members for selection, and each of the beams projected from the plurality of drawing units onto the substrate. A pattern drawing device that adjusts the strength to match. The pattern drawing apparatus according to claim 4,
The control unit is configured to measure 0 of the beam from the light source device that passes through the plurality of the acousto-optic modulation elements in order to measure the efficiency of the acousto-optic modulation elements constituting each of the plurality of selection optical members. A pattern drawing apparatus using a signal from a photoelectric sensor for detecting the intensity of the next light. The pattern drawing apparatus according to claim 1,
The selection optical member includes an electro-optical element that changes a polarization state of a beam from the light source device according to a change in refractive index, and a polarization separation element that deflects the beam toward the drawing unit according to the polarization state. Pattern drawing device. A pattern drawing device that draws a pattern on the substrate by a plurality of drawing units that draw a pattern by scanning the beam from the light source device on the substrate with a scanning member,
In order to selectively supply the beam from the light source device to any one of the plurality of drawing units, the beam from the light source device is arranged to pass through in order, and the beam is controlled by electrical control. A beam switching unit having a plurality of optical members for selection directed to the drawing unit;
A plurality of beam intensity adjusting units that are provided corresponding to each of the plurality of drawing units and that can adjust the intensity of the beam projected onto the substrate within a predetermined range;
Of the plurality of selection optical members, the intensity of the beam selected by the selection optical member that finally enters the beam from the light source device and projected onto the substrate through the drawing unit can be adjusted. A control unit that controls the plurality of beam intensity adjusting units so as to align the intensity of beams projected from the plurality of drawing units to the substrate based on a range;
A pattern drawing apparatus. The pattern drawing apparatus according to claim 7,
The pattern drawing apparatus, wherein the selection optical member is an acousto-optic modulation element that deflects a beam from the light source device toward the drawing unit by a diffraction action. It is a pattern drawing apparatus of Claim 8, Comprising:
The pattern drawing apparatus, wherein the beam intensity adjusting unit includes a drive circuit that adjusts a drive signal of the acousto-optic modulation element so as to adjust the efficiency of the acousto-optic modulation element as the selection optical member. It is a pattern drawing apparatus of Claim 9, Comprising:
The control unit compares the adjustable range of the efficiency of the acousto-optic modulator that constitutes each of the plurality of optical members for selection, and each of the beams projected from the plurality of drawing units onto the substrate. A pattern drawing device that adjusts the strength to match. It is a pattern drawing apparatus of Claim 10, Comprising:
The control unit is configured to measure 0 of the beam from the light source device that passes through the plurality of the acousto-optic modulation elements in order to measure the efficiency of the acousto-optic modulation elements constituting each of the plurality of selection optical members. A pattern drawing apparatus using a signal from a photoelectric sensor for detecting the intensity of the next light. The pattern drawing apparatus according to claim 7,
The selection optical member includes an electro-optical element that changes a polarization state of a beam from the light source device according to a change in refractive index, and a polarization separation element that deflects the beam toward the drawing unit according to the polarization state. Pattern drawing device. A pattern drawing device for drawing a pattern on the substrate by a plurality of drawing units for drawing a pattern by scanning a beam from a light source device on the substrate with a scanning member,
An electro-optic selection optical member for deflecting a beam from the light source device toward the drawing unit is provided corresponding to each of the plurality of drawing units, and a plurality of beams from the light source device are provided to the drawing unit. A beam switching unit having a plurality of optical elements for guiding light to pass through each of the optical members for selection in order;
A switching control unit for supplying a drive signal for deflection to one of the plurality of selection optical members so as to selectively supply a beam from the light source device to one of the plurality of drawing units. When,
The beam that is supplied to each of the plurality of drawing units by detecting the intensity of a non-deflected beam that has passed through the selection optical member to which the drive signal is given among the plurality of selection optical members. A beam intensity measurement unit for measuring the intensity of
A pattern drawing apparatus. It is a pattern drawing apparatus of Claim 13, Comprising:
The selection optical member is an acousto-optic modulation element that generates the non-deflected beam together with a beam that deflects the beam from the light source device toward the drawing unit in response to the drive signal. Pattern drawing device. It is a pattern drawing apparatus of Claim 13, Comprising:
The selection optical member includes an electro-optical element that generates the undeflected beam together with a beam that deflects the beam from the light source device toward the drawing unit in response to the drive signal. Drawing device. A pattern drawing device for drawing a pattern on the substrate by a plurality of drawing units for drawing a pattern by scanning a beam from a light source device on the substrate with a scanning member,
Acousto-optic modulation elements for deflecting a beam from the light source device toward the drawing unit are provided corresponding to each of the plurality of drawing units, and a beam from the light source device is provided to the plurality of acousto-optic modulation elements. A beam switching unit having a plurality of optical elements that guide the light so as to pass through each in turn,
A controller that switches one of the plurality of acoustooptic modulators to a deflected state so as to sequentially supply a beam from the light source device to one of the plurality of drawing units;
The intensity of the non-deflected beam transmitted through the acousto-optic modulation element in the deflected state among the plurality of acousto-optic modulation elements is detected, and the beam supplied to each of the plurality of drawing units is detected. A beam intensity measurement unit for measuring the intensity;
A pattern drawing apparatus. The pattern drawing apparatus according to claim 16, wherein
The beam intensity measurement unit includes a first photoelectric sensor that detects the intensity of the beam from the light source device that is incident on the front-stage acoustooptic modulator among the plurality of acoustooptic modulators;
A second photoelectric sensor that detects the intensity of the undeflected beam that has passed through each of the plurality of acoustooptic modulators;
A pattern drawing apparatus. The pattern drawing apparatus according to claim 17,
The beam intensity measurement unit outputs a photoelectric signal output from the first photoelectric sensor and the second photoelectric sensor each time one of the plurality of acousto-optic modulation elements is switched to a deflected state by the control unit. A pattern drawing apparatus that calculates information on the efficiency of each of the plurality of acoustooptic modulators based on the information. The pattern drawing apparatus according to claim 18,
The beam intensity measurement unit includes a plurality of third photoelectric sensors provided so as to receive the beams deflected by the plurality of acousto-optic modulation elements and supplied to the drawing units, respectively. Pattern drawing device. The pattern drawing apparatus according to claim 19,
The beam intensity measurement unit is based on photoelectric signals output from each of the second photoelectric sensor and the plurality of third photoelectric sensors, and information on the efficiency of each of the plurality of acousto-optic modulation elements. The pattern drawing apparatus which calculates the information regarding the transmittance | permeability of these several acousto-optic modulation elements.

Images