JP7021637B2 - Pattern drawing device - Google Patents

Description

The present invention relates to a pattern drawing apparatus that scans a spot of a beam on a substrate as an irradiated object and draws a predetermined pattern on the substrate.

Conventionally, the spot light of a laser beam is projected onto an irradiated object (processed object), and the spot light is mainly scanned in a one-dimensional direction by a scanning mirror (polygon mirror) while the irradiated object is in the main scanning line direction. In order to form a desired pattern or image (characters, figures, etc.) on an irradiated object by moving in orthogonal sub-scanning directions, for example, an image forming apparatus (drawing apparatus) as in JP-A-2008-195019. )It has been known.

In Japanese Unexamined Patent Publication No. 2008-195019, each of a plurality of scanning regions (shared regions) set on a photosensitive material, which is a photographic printing paper, is divided and scanned by an exposure beam from a laser exposure unit to scan the photosensitive material. Relationship between the temperature change of the laser exposure unit and the intensity change of the exposure beam, which are obtained in advance, so that the exposure amount due to the exposure beam does not change due to the temperature change of a plurality of laser exposure units when forming (drawing) an image. Based on 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 joint of the scanning region covered by each laser exposure unit. The image forming apparatus of JP-A-2008-195019 has three laser light sources that output laser light in each of the red, green, and blue wavelength bands corresponding to the three primary colors of light to each of the three laser exposure units. From each of the three acoustic-optical modulation elements (AOM) and each of the three AOMs, which individually modulate the intensities of the red laser light, green laser light, and blue laser light from each of the three laser light sources according to the image data. A half mirror that superimposes three laser beams on one, a rotating polygon mirror that scans one superimposed laser beam, and a laser beam scanned by the polygon mirror for constant velocity scanning on a photosensitive material. The fθ lens and the like are provided.

In Japanese Unexamined Patent Publication No. 2008-195019, the temperature of the laser light source and the AOM is controlled by the temperature control unit, but 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 beam 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 control or an overshoot phenomenon that may occur while the temperature inside the housing deviates slightly from the set temperature and returns to the original temperature, each of them. The fluctuation of the exposure amount in the laser exposure unit is corrected by adjusting the modulation level of the AOM, and the density unevenness due to the discontinuous difference in the exposure amount at the boundary of the shared region on the photosensitive material is suppressed.

A first aspect of the present invention is a pattern drawing device that draws a pattern on the substrate by a plurality of drawing units that scan a beam from a light source device on the substrate by a scanning member to draw a pattern. In order to selectively supply the beam from the light source device to any one of the plurality of drawing units, the beams from the light source device are arranged so as to pass in order, and the beam is drawn by electrical control. A beam switching unit having a plurality of acoustic-optical modulation elements directed toward the unit, a beam intensity adjusting unit for adjusting the intensity of a beam projected from a specific drawing unit among the plurality of drawing units onto the substrate, and a beam intensity adjusting unit . A control unit for controlling the beam intensity adjusting unit is provided , and the control unit compares the adjustable range of the efficiency of the plurality of acoustic-optical modulation elements from each of the plurality of drawing units to the substrate. The beam intensity adjusting unit is controlled so that the intensities of the projected beams are the same .

A second aspect of the present invention is a pattern drawing device that draws a pattern on the substrate by a plurality of drawing units that scan a beam from a light source device on the substrate with a scanning member to draw a pattern, and the light source. An acoustic-optical modulation element for deflecting the beam from the apparatus toward the drawing unit is provided corresponding to each of the plurality of drawing units, and the beam from the light source device is provided for each of the plurality of acoustic-optical modulation elements. A beam switching unit having a plurality of optical elements for guiding light in order, and the plurality of acoustic optics so as to sequentially supply a beam from the light source device to one of the plurality of drawing units. The control unit that switches one of the modulation elements to the deflection state and the intensity of the beam in the non-deflection state that has passed through the acoustic-optical modulation element that is in the deflection state among the plurality of acoustic-optical modulation elements are detected. The beam intensity measuring unit is provided with a beam intensity measuring unit for measuring the intensity of the beam supplied to each of the plurality of drawing units, and the beam intensity measuring unit is the frontmost acoustic of the plurality of acoustic-optical modulation elements. A first photoelectric sensor that detects the intensity of the beam from the light source device incident on the optical modulation element, and a second photoelectric sensor that detects the intensity of the beam in the non-deflected state that has passed through each of the plurality of acoustic optical modulation elements. The beam intensity measuring unit includes a photoelectric sensor, and the beam intensity measuring unit includes the first photoelectric sensor and the second photoelectric sensor each time one of the plurality of acoustic-optical modulation elements is switched to a deflection state by the control unit. Information on the efficiency of each of the plurality of acoustic-optical modulation elements is calculated based on the photoelectric signal output from .

It is a perspective view which shows the schematic whole structure of the pattern drawing apparatus by 1st Embodiment. It is a perspective view which shows the specific structure of the drawing unit mounted on the pattern drawing apparatus shown in FIG. It is a figure which shows the specific optical arrangement of the optical element for selection and the incident mirror shown in FIG. It is a figure which shows the schematic structure of the beam switching part and the drawing control device for selectively distributing a beam from a light source device to any of 6 drawing units. It is a figure explaining the connection relation of the strength adjustment control unit, the drive circuit, etc. provided in the drawing control apparatus shown in FIG. It is a graph which shows an example of the change characteristic of the diffraction efficiency by the change of the RF power of the drive signal applied to the optical element for selection. It is a graph which shows an example of the relationship between the intensity of the beam supplied to each of the drawing units, and the adjustable range in the selection optical element which adjusts the intensity of the beam. It is a figure which schematically explains the influence by the efficiency and transmittance of each of the plurality of selection optical elements arranged in series along the traveling direction of the beam from a light source device.

The pattern drawing apparatus according to the aspect of the present invention will be described in detail below with reference to the attached drawings, with reference to suitable embodiments. It should be noted that the aspects of the present invention are not limited to these embodiments, but include those with various changes or improvements. That is, the components described below include those that can be easily assumed by those skilled in the art and those that are substantially the same, and the components described below can be appropriately combined. In addition, various omissions, substitutions or changes of components can be made without departing from the gist 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 (irradiated body) P according to the first embodiment. In the following description, unless otherwise specified, an XYZ Cartesian coordinate system with the gravity direction as 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 figure.

The pattern drawing apparatus EX is a substrate processing apparatus used in a device manufacturing system that manufactures an electronic device by subjecting a substrate P to a predetermined process (exposure process or the like). The device manufacturing system is, for example, a manufacturing line in which a manufacturing line for manufacturing flexible displays as electronic devices, film-shaped touch panels, film-shaped color filters for liquid crystal display panels, flexible wiring, flexible sensors, etc. is constructed. It is a system. Hereinafter, a flexible display will be described as an electronic device. Flexible displays include, for example, organic EL displays and liquid crystal displays. In the device manufacturing system, the substrate P is delivered from a supply roll (not shown) in which a flexible sheet-shaped substrate (sheet substrate) P is wound in a roll shape, and various processes are continuously performed on the sent substrate P. It has a so-called roll-to-roll (Roll To Roll) production method in which the substrate P after various treatments is wound up with a recovery roll (not shown). Therefore, the substrate P after various treatments is a multi-chamfering substrate in which a plurality of devices (display panels) are arranged in a state of being 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 apparatus of the pre-process, the pattern drawing apparatus EX, and the process apparatus of the post-process, and is wound up by the recovery roll. The substrate P has a strip-shaped shape in which the moving direction (transporting direction) of the substrate P is the longitudinal direction (long direction) and the width direction is the lateral direction (short direction).

As the substrate P, for example, a resin film, a foil made of a metal or an alloy such as stainless steel, or the like is used. Examples of the material of the resin film 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. Of these, those containing at least one may be used. Further, the thickness and rigidity (Young's modulus) of the substrate P are within a range in which the substrate P does not have creases or irreversible wrinkles due to buckling when passing through the transport path of the device manufacturing system or the pattern drawing device EX. It should be. A film such as PET (polyethylene terephthalate) or PEN (polyethylene naphthalate) having a thickness of about 25 μm to 200 μm as a base material of the substrate P 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 a substrate P made of a material whose thermal expansion coefficient is not significantly large. For example, the coefficient of thermal expansion can be suppressed by mixing the inorganic filler with the resin film. The inorganic filler may be, for example, titanium oxide, zinc oxide, alumina, silicon oxide or the like. Further, the substrate P may be a single layer of ultrathin glass having a thickness of about 100 μm manufactured by a float method or the like, or a laminated body in which the above resin film, foil or the like is bonded to the ultrathin glass. May be.

By the way, the flexibility of the substrate P means a property that the substrate P can be flexed without being sheared or broken even if a force of about its own weight is applied to the substrate P. .. Flexibility also includes the property of bending by a force of about its own weight. Further, the degree of flexibility varies depending on the material, size, thickness of the substrate P, the layer structure formed on the substrate P, the temperature, the environment such as humidity, and the like. In any case, when the substrate P is correctly wound around various transport rollers, rotary drums, and other transport direction changing members provided in the transport path in the device manufacturing system (pattern drawing device EX), it buckles and creases. It can be said that the range of flexibility is such that the substrate P can be smoothly conveyed without being damaged or damaged (tear or cracked).

The process apparatus (including a single processing unit or a plurality of processing units) in the previous process transports the substrate P sent from the supply roll toward the pattern drawing apparatus EX at a predetermined speed along a long direction. At the same time, the process of the previous process is performed on the substrate P sent to the pattern drawing apparatus EX. The substrate P sent to the pattern drawing apparatus EX by the process of this previous step is a substrate (photosensitive substrate) having a photosensitive functional layer (photosensitive layer) formed on its surface.

This photosensitive functional layer is applied as a solution on the substrate P and dried to form a layer (film). A typical photosensitive functional layer is a photoresist (liquid or dry film), but as a material that does not require development processing, the photosensitive functional layer is modified in terms of the liquid repellency of the portion exposed to ultraviolet rays. There is a silane coupling agent (SAM), or a photosensitive reducing agent in which a plating reducing group is exposed on 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 liquid repellent to liquid repellent. Therefore, by selectively coating a conductive ink (ink containing conductive nanoparticles such as silver and copper) or a liquid containing a semiconductor material on the portion that has become liquid-friendly, a thin film (TFT) or the like can be used. It is possible to form a pattern layer as a wiring for electrodes, semiconductors, insulation, or connections constituting the above. When a photosensitive reducing agent is used as the photosensitive functional layer, the plating reducing group is exposed on the pattern portion exposed to ultraviolet rays on the substrate P. Therefore, after the exposure, the substrate P is immediately immersed in a plating solution containing palladium ions or the like for a certain period of time to form (precipitate) a pattern layer made of palladium. Such a plating process is an additive process, but in addition, an etching process as a subtractive process may be premised. In that case, the substrate P sent to the pattern drawing apparatus EX uses PET or PEN as the base material, and a metallic thin film such as aluminum (Al) or copper (Cu) is deposited on the entire surface thereof or selectively, and further, the substrate P thereof is deposited. It is preferable to laminate a photoresist layer on top.

The pattern drawing apparatus EX conveys the substrate P conveyed from the process apparatus of the previous process to the process apparatus of the subsequent process (including a single processing unit or a plurality of processing units) at a predetermined speed, while conveying the substrate. This is a processing device that performs exposure processing on P. The pattern drawing device EX corresponds to a pattern for an electronic device (for example, a pattern such as a TFT electrode or wiring constituting the electronic device) on the surface of the substrate P (the surface of the photosensitive functional layer, that is, the photosensitive surface). Irradiate the light pattern. As a result, 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 without a mask, a so-called spot scanning type exposure apparatus (drawing apparatus), as shown in FIG. The exposure device EX has a plurality of rotary drum DRs that support the substrate P for sub-scanning and convey it in a long direction, and a plurality of patterns that perform pattern exposure for each portion of the substrate P that is supported in a cylindrical surface by the rotary drum DR. Here, 6) drawing units Un (U1 to U6) are provided, and each of the plurality of drawing units Un (U1 to U6) has a spot light SP of a pulsed beam LB (pulse beam) for exposure. Pattern data (drawing data) of the intensity of the spot light SP while scanning (main scanning) one-dimensionally with a polygon mirror (scanning member) in a predetermined scanning direction (Y direction) on the irradiated surface (photosensitive surface) of the substrate P. , Pattern information) at high speed modulation (on / off). As a result, an optical 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, in the sub-scanning of the substrate P and the main scanning of the spot light SP, the spot light SP is relatively two-dimensionally scanned on the irradiated surface (the surface of the photosensitive functional layer) of the substrate P, and the substrate P is scanned. A predetermined pattern is drawn and exposed on the irradiated surface. Further, since the substrate P is conveyed along the elongated direction, a plurality of exposed regions to which the pattern is exposed by the exposure apparatus EX are provided along the elongated direction of the substrate P at predetermined intervals. It will be. Since the 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 the direction in which gravity acts, and a cylindrical outer peripheral surface having a constant radius from the central axis AXo. The rotary drum DR rotates around the central axis AXo while supporting (holding) a part of the substrate P by bending it in a cylindrical surface shape in the elongated direction following the outer peripheral surface (circumferential surface). P is conveyed in the long direction. The rotary drum DR supports a region (part) on the substrate P on which the beam LB (spot light SP) from each of the plurality of drawing units Un (U1 to U6) is projected by its outer peripheral surface. The rotary drum DR supports (closely holds) the substrate P from the surface (rear surface) side opposite to the surface on which the electronic device is formed (the surface on which the photosensitive surface is formed). On both sides of the rotary drum DR in the Y direction, shafts (not shown) supported by bearings so as to rotate the rotary drum DR around the central axis AXo are provided. Rotational torque from a rotational drive source (for example, a motor, a deceleration mechanism, etc.) (not shown) is applied to the shaft, and the rotary drum DR rotates at a constant rotational speed around the central axis AXo.

The light source device (pulse light source device) LS generates and emits a pulsed beam (pulse beam, pulse 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 light in a pulse shape at a frequency (oscillation frequency, predetermined frequency) Fa under the control of a drawing control device 200 (described with reference to FIG. 4) (not shown here). This light source device LS is a semiconductor laser element that generates pulsed light in the infrared wavelength region, a fiber amplifier, and a wavelength conversion element (harmonic) that converts the amplified pulsed light in the infrared wavelength region into pulsed light in the ultraviolet wavelength region. A fiber amplifier laser light source composed of a wave generating element) or the like. By configuring the light source device LS in this way, it is possible to obtain high-intensity ultraviolet pulse light having an oscillation frequency Fa of several hundred MHz and a light emission time of one pulse light of several tens of picoseconds or less. It is assumed that the beam LB emitted from the light source device LS has a thin parallel light beam having a beam diameter of about 1 mm or less. For a configuration in which the light source device LS is used as 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”), for example. , International Publication No. 2015/166910.

The 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, and 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 elements OSn (OS1 to OS6) have transparency with respect to the beam LB, and are driven by an ultrasonic signal to use the incident primary diffracted light of the beam LB as a predetermined beam LBn for drawing. It is composed of an acousto-optic modulation element (AOM: Acousto-Optic Modulator) that deflects and emits light 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 elements OS2 to OS6 and the incident mirrors IM2 to IM6 correspond to the drawing units U2 to U6, respectively. It is provided.

The optical path of the beam LB from the light source device LS is bent in a zigzag shape in a plane parallel to the XY plane by the reflection mirrors M1 to M12, and is guided to the absorber TR. Hereinafter, the case where the selection optical elements OSn (OS1 to OS6) are all off (a state in which an ultrasonic signal is not applied and primary diffracted light is not 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 luminous flux. Or, the beam LB emitted after convergence is returned to the parallel luminous 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 in parallel with the X axis and is incident on the reflection mirror M1. The beam LB reflected in the −Y direction by the reflection mirror M1 is incident on the reflection mirror M2. The beam LB reflected in the + X direction by the reflection mirror M2 linearly passes through the selection optical element OS 5 and reaches the reflection mirror M3. The beam LB reflected in the −Y direction by the reflection mirror M3 is incident on the reflection mirror M4. The beam LB reflected in the −X direction by the reflection mirror M4 linearly passes through the selection optical element OS 6 and reaches the reflection mirror M5. The beam LB reflected in the −Y direction by the reflection mirror M5 is incident on the reflection mirror M6. The beam LB reflected in the + X direction by the reflection mirror M6 linearly passes 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 is incident on the reflection mirror M8. The beam LB reflected in the −X direction by the reflection mirror M8 linearly passes 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 is incident on the reflection mirror M10. The beam LB reflected in the + X direction by the reflection mirror M10 linearly passes 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 is incident on the reflection mirror M12. The beam LB reflected in the −X direction by the reflection mirror M12 linearly passes through the selection optical element OS2 and is 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, each selection optical element OSn emits first-order diffracted light obtained by diffracting an incident beam (0th-order light) LB at a diffraction angle corresponding to a high-frequency frequency. It is generated as (beam LBn for drawing). Therefore, the beam emitted as the primary diffracted light from the selection optical element OS1 becomes LB1, and the beam emitted as the primary diffracted light from the selection optical elements OS2 to OS6 becomes LB2 to LB6. As described above, each selection optical element OSn (OS1 to OS6) functions to deflect the optical path of the beam LB from the light source device LS. In the present embodiment, the state in which the selection optical elements OSn (OS1 to OS6) are turned on and the beam LBn (LB1 to LB6) as the primary diffracted light is generated is defined as the selection optical element OSn (OSn). OS1 to OS6) will be described as a state in which the beam LB from the light source device LS is deflected (or selected). However, since the maximum generation efficiency of the first-order diffracted light is about 80% of the 0th-order light in the actual acoustic-optical modulation element, the beam LBn (LB1 to LB6) deflected by each of the selection optical elements OSn is used. It is lower than the intensity of the original beam LB. Further, in the present embodiment, the drawing control device 200 (see FIG. 4) controls so that only one of the selection optical elements OSn (OS1 to OS6) is turned on for a certain period of time. Ru. When one selected optical element OSn for selection is in the ON state, about 20% of the 0th-order light that travels straight without being diffracted by the optical element OSn for selection remains, but it is finally absorbed by the absorber TR. Ru.

Each of the selection optical elements OSn is installed so as to deflect the beam LBn (LB1 to LB6) for drawing, which is the deflected primary diffracted light, in the −Z direction with respect to the incident beam LB. The beam LBn (LB1 to LB6) deflected and emitted by each of the selection optical elements OSn is projected onto the incident mirror Imn (IM1 to IM6) provided at a position separated from each of the selection optical elements OSn by a predetermined distance. Will be done. Each incident mirror Imn guides the beam LBn (LB1 to LB6) to the corresponding drawing units Un (U1 to U6) by reflecting the incident beam LBn (LB1 to LB6) in the −Z direction.

The same configuration, function, operation, and the like of each selection optical element OSn may be used. Each of the plurality of selection optical elements OSn turns on / off the generation of diffracted light (beam LBn) that diffracts the incident beam LB according to the on / off of the drive signal (ultrasonic signal) from the drawing control device 200. Turn off. For example, the selection optical element OS 5 transmits the beam LB from the incident light source device LS without deflecting (diffraction) 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 OS 5 is incident on the reflection mirror M3. On the other hand, when the selection optical element OS 5 is in the ON state, the incident beam LB is deflected (diffracted) and directed toward the incident mirror IM5. That is, the switching (beam selection) operation by the selection optical element OS 5 is controlled by turning the drive signal on / off. In this way, the beam LB from the light source device LS can be guided to any one drawing unit Un by the switching operation of each selection optical element OSn, and the drawing unit Un on which the beam LBn is incident can be switched. Can be done. In this way, the configuration is such that a plurality of selection optical elements OSn are arranged in series (serial) so that the beam LBs from the light source device LS pass in order, and the beam LBn is supplied to the corresponding drawing unit Un in a time-division manner. Is disclosed in International Publication No. 2015/166910 Pamphlet.

The order in which each of the selection optical elements OSn (OS1 to OS6) constituting the beam switching unit is turned on for a certain period of time is, for example, OS1 → OS2 → OS3 → OS4 → OS5 → OS6 → OS1 → ... In addition, it is predetermined. This order is determined by the order of scanning start timings by spot light set in each of the drawing units Un (U1 to U6). That is, in the present embodiment, one of the drawing units U1 to U6 is synchronized by synchronizing the rotation speeds of the polygon mirrors provided in each of the six drawing units U1 to U6 and also the phase of the rotation angle. One reflective surface of the polygon mirror in one can be switched to time division so that one spot scan is performed on the substrate P. Therefore, the order of spot scanning of the drawing unit Un may be any order as long as the phases of the rotation angles of the polygon mirrors of the drawing unit Un are synchronized in a predetermined relationship. In the configuration of FIG. 1, three drawing units U1, U3, and U5 are arranged side by side in the Y direction on the upstream side of the substrate P in the transport direction (the direction in which the outer peripheral surface of the rotating drum DR moves in the circumferential direction), and the substrate P is arranged. Three drawing units U2, U4, and U6 are arranged side by side 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 odd-numbered drawing units U1, U3, and U5 on the upstream side, and when the substrate P is sent for a certain length, the even-numbered drawing units U2, U4, and U6 on the downstream side are sent. Since pattern drawing is also started, the order of spot scanning of the drawing unit Un can be set to 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 certain period of time is defined as 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 turned on, 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, each of the polygon mirror PMs of each drawing unit Un is synchronously controlled so as to maintain a constant rotation angle phase with each other while precisely rotating at the same rotation speed. Thereby, the timings of the main scans of the beams LB1 to LB6 projected from each of the drawing units U1 to U6 onto the substrate P (main scan period of the spot light SP) can be set so as not to overlap each other. Therefore, by controlling the on / off switching of each of the selection optical elements OSn (OS1 to OS6) provided in the beam switching unit in synchronization with the rotation angle position of each of the six polygon mirror PMs, the light source is used. Efficient exposure processing can be performed by distributing the beam LB from the apparatus LS to each of the plurality of drawing units Un in a time-division manner.

For the synchronization control between the phase matching of the rotation angle of each of the six polygon mirror PMs and the on / off switching timing of each of the optical elements OSn (OS1 to OS6) for selection, refer to the International Publication No. 2015/166910 pamphlet. Although disclosed, in the case of the 8-sided polygon mirror PM, about 1/3 of the rotation angle (45 degrees) for one reflecting surface is one scan of the spot light SP on the substrate P as the scanning efficiency. Therefore, the six polygon mirrors PM are rotated by relatively shifting the phase of the rotation angle by 15 degrees, and each polygon mirror PM is selected to scan the beam LBn by skipping eight reflective surfaces. Switching on / off of each of the optical elements OSn (OS1 to OS6) is controlled. As described above, a drawing method in which the reflective surface of the polygon mirror PM is skipped by one surface is also disclosed in the International Publication No. 2015/166910 pamphlet.

As shown in FIG. 1, the exposure apparatus EX is a so-called multi-head type 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 of the substrate P supported by the outer peripheral surface (circumferential surface) of the rotating drum DR, which is partitioned in the Y direction. Each drawing unit Un (U1 to U6) focuses (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). As a result, 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 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. Will be done. The drawing line SLn is also a scanning locus of the spot light SP of the beam LBn on the substrate P.

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 the central axis AXo of the rotating drum DR and sandwich the central surface parallel to the YZ plane. They are arranged in a staggered arrangement in two rows in the circumferential direction of the 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) of the substrate P in the transport direction with respect to the central surface, and are along the Y direction. They are arranged in a row at predetermined intervals. The even-numbered drawing lines SL2, SL4, and SL6 are located on the irradiated surface of the substrate P on the downstream side (+ X direction side) of the substrate P in the transport direction with respect to the central surface, and are predetermined along the Y direction. They are arranged in a row at intervals 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 with the central plane interposed therebetween, and the odd-numbered drawing units U1, U3, and U5 and the even-numbered drawing units are drawn. The units U2, U4, and U6 are provided symmetrically with respect to the central plane when viewed in the XZ plane.

In 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 in the Y direction ( The width direction and the main scanning direction of the substrate P) are set so as to be joined 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 rotating drum DR. By joining the drawing lines SLn in the Y direction, the end of the drawing line SLn is joined so that the patterns drawn by each of the drawing lines SLn adjacent to each other in the Y direction are joined in the Y direction on the substrate P. It means that the positions in the Y direction of each other are adjacent to each other or partially overlapped with each other. When the ends of the drawing lines SLn are overlapped with each other, for example, it is preferable to overlap the lengths of the drawing lines SLn within a range of several% or less in the Y direction including the drawing start point or the drawing end point. ..

In this way, the plurality of drawing units Un (U1 to U6) share the scanning area (division of the main scanning range) in the Y direction so as to cover the dimension in the width direction of the exposed area on the substrate P as a whole. ing. For example, assuming that the main scanning range (the length of the drawing line SLn) in the Y direction by one drawing unit Un is about 30 to 60 mm, drawing is possible by arranging a total of six drawing units U1 to U6 in the Y direction. The width of the exposed area in the Y direction is widened to about 180 to 360 mm. The length (length of the drawing range) of each drawing line SLn (SL1 to SL6) is the same in principle. That is, in principle, the scanning distances of the spot light SPs of the beams LBn scanned along each of the drawing lines SL1 to SL6 are 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 scan is a 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 the 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 (rotational speed of the polygon mirror PM) of the spot light SP and the spot light SP so that the spot light SP overlaps with the effective size (dimension) φ by about φ × 1/2. The oscillation frequency Fa is set. Therefore, the projection interval of the pulsed spot light SP along the main scanning direction is φ / 2. Therefore, even in the sub-scanning direction (direction intersecting the drawing line SLn), the substrate P is effective for the spot light SP between one scan of the spot light SP along the drawing line SLn and the next scanning. It is desirable to set it so that it moves by a distance of approximately 1/2 of the size φ. Further, even when the drawing lines SLn adjacent to each other in the Y direction are connected in the main scanning direction, it is desirable to overlap by φ / 2. In this 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 so that each beam LBn advances toward the central axis AXo of the rotating drum DR when viewed in the XZ plane. As a result, the optical path (beam main 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 each drawing unit Un (U1 to U6) to the drawing lines SLn (SL1 to SL6) is relative to the tangent plane at the drawing line SLn on the surface of the substrate P curved in a cylindrical surface. It is projected toward the substrate P so that it is always vertical. That is, the beams LBn (LB1 to LB6) projected on the substrate P are scanned in a telecentric state with respect to the main scanning direction of the spot light SP.

Since the drawing unit (beam scanning device) Un shown in FIG. 1 has the same configuration, only the drawing unit U1 will be briefly described. The detailed configuration of the drawing unit U1 will be described later with reference to FIG. The drawing unit U1 includes at least a reflection mirror M20 to M24, a polygon mirror PM, and an fθ lens system (scanning lens for drawing) FT. Although not shown in FIG. 1, the first cylindrical lens CYa (see FIG. 2) is arranged in front of the polygon mirror PM when viewed from the traveling direction of the beam LB1, and the fθ lens system (f−θ lens system) is arranged. ) 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 is incident on the reflection mirror M20 provided in the drawing unit U1, and the beam LB1 reflected by the reflection mirror M20 travels in the −X direction and is incident on the reflection mirror M21. do. The beam LB1 reflected by the reflection mirror M21 in the −Z direction is incident on the reflection mirror M22, and the beam LB1 reflected by the reflection mirror M22 travels in the + X direction and is incident on 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 bend in a plane parallel to the XY plane.

The polygon mirror PM reflects the incident beam LB1 toward the fθ lens system FT in the + X direction. 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 polymorphic mirror, scanning member) PM has a rotation axis AXp extending in the Z-axis direction and a plurality of reflection surface RPs (books) formed around the rotation axis AXp in parallel with the rotation axis AXp. In the embodiment, the number Np of the reflecting surface RP is 8). By rotating this polygon mirror PM around the rotation axis AXp in a predetermined rotation direction, the reflection angle of the pulsed beam LB1 irradiated on the reflection surface can be continuously changed. 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 (width direction of the substrate P, Y direction). can do. Therefore, 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 surface RP at the maximum.

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 becomes a spot light SP via the reflection mirror M24 and is projected onto the substrate P. At this time, the reflection mirror M24 reflects the beam LB1 toward the substrate P so that the beam LB1 advances toward the central axis AXo of the rotating drum DR with respect to the XZ plane. The angle of incidence θ of the beam LB1 on the fθ lens system FT changes according to the rotation angle (θ / 2) of the polygon mirror PM. The fθ lens system FT projects the beam LB1 at the image height position on the irradiated surface of the substrate P in proportion to the incident angle θ thereof via the reflection mirror M24. Assuming that 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, this fθ lens system FT makes it possible to scan the beam LB1 in the Y direction accurately at a constant velocity. The surface (parallel to the XY surface) in which the beam LB1 incident on the fθ lens system FT is one-dimensionally deflected by the polygon mirror PM is the surface including the optical axis AXf of the fθ lens system FT.

Next, the optical configuration of the drawing units Un (U1 to U6) will be described with reference to FIG. As shown in FIG. 2, in the drawing unit Un, the reflection mirror M20, the reflection mirror M20a, and the polarizing beam splitter BS1 are included along the traveling direction of the beam LBn from the incident position of the beam LBn to the irradiated surface (substrate P). , Reflective mirror M21, Reflective mirror M22, First cylindrical lens CYa, Reflective mirror M23, Polygon mirror PM, fθ lens system FT, Reflective mirror M24, Second cylindrical lens CYb. Further, in the drawing unit Un, an origin sensor (origin detection) that detects the angular position of each reflective 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 light transmitting system 60a and a beam light receiving system 60b as a device) are provided. Further, in the drawing unit Un, the reflected light of the beam LBn reflected by the irradiated surface (or the surface of the rotating drum DR) of the substrate P is transferred to the fθ lens system FT, the polygon mirror PM, the polarization beam splitter BS1 and the like. A photodetector (photoelectric sensor) DTc for detection 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 is incident on the reflection mirror M20 tilted at 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 away from the reflection mirror M20 in the −X direction. The reflection mirror M20a is arranged at an angle of 45 ° with respect to the YZ plane, and reflects the incident beam LBn toward the polarizing beam splitter BS1 in the −Y direction. The polarization separation surface of the polarization beam splitter BS1 is arranged at an angle of 45 ° with respect to the YZ plane, reflects the P-polarized beam, and transmits the linearly polarized (S-polarized) beam polarized in the direction orthogonal to the P-polarized light. Assuming that the beam LBn incident on the drawing unit Un is a P-polarized beam, the polarizing 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 arranged 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 away from the reflection mirror M21 in the −Z direction. The beam LBn reflected by the reflection mirror M21 is incident on the reflection mirror M22. The reflection mirror M22 is arranged at an angle 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 is incident on the reflection mirror M23 via a λ / 4 wave 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 the fθ lens system FT having the 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 the present 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. Will be done. The rotation motor RM is rotated 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 device 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 this polygon mirror PM. The length is set to the following, 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) by the polygon mirror PM. That is, the cylindrical lens CYa converges the beam LBn into a slit shape (oblong shape) extending in a direction parallel to the XY plane on the reflection surface of the polygon mirror PM. Even when the reflective surface of the polygon mirror PM is tilted from a state parallel to the Z axis (rotation axis AXp) due to the cylindrical lens CYa whose generatrix is parallel to the Y direction and the 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.

The angle of incidence θ (angle with respect to the optical axis AXf) of the beam LBn on the fθ lens system FT changes according to the rotation angle (θ / 2) of the polygon mirror PM. When the angle of incidence θ of the beam LBn on the fθ lens system FT is 0 degrees, the beam LBn incident on the fθ lens system FT travels 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 projected toward the substrate P via the cylindrical lens CYb. The beam LBn projected on the substrate P by the fθ lens system FT and the cylindrical lens CYb whose generatrix 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 in 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. It is projected on P. Each of the six drawing units U1 to U6 one-dimensionally scans each spot light SP of the beams LB1 to LB6 in the main scanning direction (Y direction), and conveys the substrate P in the elongated direction to convey the substrate P to the substrate P. The irradiated surface is relatively two-dimensionally scanned by the spot light SP, and the patterns drawn on each of the drawing lines SL1 to SL6 are exposed on the substrate P in a state of being spliced 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 spot light SP is pulsed so as to overlap each other by 1/2 of the diameter φ along the drawing line SLn (main scanning direction), the interval in the main scanning direction of the pulse emission of the spot light SP is on the substrate P. It becomes 2 μm, which corresponds to 2.5 nS (1/400 MHz) which is a period Tf (= 1 / Fa) of the oscillation frequency Fa. Further, 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. To. Therefore, the scanning speed Vsp in the main scanning direction of the spot light SP 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 is the rotation speed VR (rpm) of the polygon mirror PM, the effective scanning length LT, the number of reflecting surfaces of the polygon mirror PM Np (= 8), and one reflecting surface of the polygon mirror PM. It is determined as follows based on the scanning efficiency of 1 / α by RP.
Vsp = (8 ・ α ・ VR ・ LT) / 60 [mm / sec]
Therefore, the oscillation frequency Fa (period Tf) and the rotation speed VR (rpm) are set to have the following relationship.
(Φ / 2) / Tf = (8 ・ α ・ VR ・ LT) / 60 ・ ・ ・ Equation 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 from 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, due to the relation of the formula A, the polygon mirror PM with 8 faces The rotation speed VR may be set to 36000 rpm. The scanning speed Vsp = 0.8 μm / nS in this case is 2880 Km / h when converted to an hourly speed.

In the beam light receiving system 60b constituting the origin sensor shown in FIG. 2, the rotation position of the reflecting surface RP of the polygon mirror PM is immediately before the scanning of the spot light SP of the beam LBn for drawing by the reflecting surface RP can be started. The origin signal SZn that changes its waveform at the moment when it reaches a predetermined position (specified angle position, origin angle position) is generated. Since the polygon mirror PM has eight reflecting surface RPs, the beam light receiving system 60b outputs the origin signal SZn eight times during one rotation of the polygon mirror PM. The origin signal SZn is sent to the drawing control device 200 (see FIG. 4), and after a predetermined delay time Tdn has elapsed after the origin signal SZn is generated, scanning along the drawing line SLn of the spot light SP is started. To.

FIG. 3 is a diagram showing a specific configuration around the selection optical elements 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 flux having a minute diameter (first diameter) of, for example, 1 mm or less. During the 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 as it is without being diffracted by the selection optical element OSn. The transmitted beam LB passes through the condenser lens Ga and the collimating lens Gb provided along the optical axis AXb on the optical path, and is incident on the selection optical element OSn in the subsequent stage. At this time, the beam LB passing through the condenser lens Ga and the collimating 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 collimated lens Gb. .. The collimating lens Gb makes the beam LB diverging from the position of the surface Ps a parallel light flux. The diameter of the beam LB made into a parallel light flux by the collimating lens Gb is the first diameter. The rear focal position of the condenser 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 condenser lens Ga is in the selection optical element OSn. It is arranged so as to coincide with the diffraction point within a predetermined allowable range.

On the other hand, during the on-state 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 0th-order beam LBnz that was not generated is generated. When the intensity of the incident beam LB is 100% and the decrease due to the transmittance of the selection optical element 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 condenser lens Ga and the collimating lens Gb, passes through the selection optical element OSn in the subsequent stage, and is absorbed by the absorber TR. The beam LBn (parallel luminous flux) 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 heads toward the incident mirror Imn provided on the surface Ps. Since the front focal position of the condenser lens Ga is optically coupled to the diffraction point in the optical element OSn for selection, the beam LBn from the condenser lens Ga toward the incident mirror Imn illuminates the position eccentric from the optical axis AXb. It travels parallel to the axis AXb and is focused (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 conjugated with the spot light SP projected on the substrate P via the drawing unit Un.

By arranging the reflection 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 by the incident mirror Imn in the −Z direction, and the collimating lens Gc. It is incident on the drawing unit Un along the optical axis AX1 (see FIGS. 2 and 3). The collimating lens Gc makes the beam LBn converged / diverged by the condenser lens Ga a parallel light flux coaxial with the optical axis (AX1) of the collimating lens Gc. The diameter of the beam LBn made into a parallel light flux by the collimating lens Gc is substantially the same as the first diameter. The posterior focal point of the condenser lens Ga and the anterior focal point of the collimating lens Gc are arranged at 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 selection optical element OSn are optically coupled, and the incident mirror Imn is arranged on the surface Ps which 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 eccentricity (shift amount) of the focusing 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 selection optical element OSn itself, the size of the reflection 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 of the reflective surface RP of the polygon mirror PM in the Z direction, the magnification from the polygon mirror PM to the substrate P (magnification of the fθ lens system FT), etc., it is effective on the substrate P of the spot light SP. It can be adjusted within a range of about the size (diameter) or about the pixel size (Pxy) defined on the drawing data. As a result, the overlay error between the new pattern drawn on the substrate P in each of the drawing units P and the pattern formed on the substrate P, or the new pattern drawn on the substrate P in each of the drawing units Un. It is possible to correct the splicing error between various patterns with high accuracy and high speed.

FIG. 4 is a schematic view of a beam switching unit including a selection optical element OSn (OS1 to OS6) for selectively distributing a beam LB from a light source device LS to any one of six drawing units U1 to U6. The configuration is shown. The reference numerals of the respective members in FIG. 4 are the same as those shown in FIG. 1, but the reflection mirrors M1 to M12 shown in FIG. 1 are appropriately omitted. The light source device LS composed of the fiber amplifier laser light source is connected to the drawing control device 200 and exchanges various control information SJs. 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 the beam LB is pulsed, and draws each drawing unit Un sent from the drawing control device 200. Burst mode (emission for a predetermined number of clock pulses and a predetermined number of clock pulses) in response to a beam LBn in response to a clock signal CLK based on data SDn (serial data from bitmap data in which one pixel is one bit). It emits a pulse by repeating the process of stopping the light emission. As described above, in the present embodiment, the light source device LS itself performs intensity modulation (switching of pulse emission on / off) of the beam LB for pattern drawing.

The drawing control device 200 inputs the origin signals SZn (SZ1 to SZ6) output from the beam light receiving units (beam light receiving system, light receiving system) 60b of the origin sensors of the drawing units U1 to U6, and the drawing units U1 to U1 to A polygon rotation control unit that controls the rotation motor RM of the polygon mirror PM and an optical element OSn (OS1 to OS6) for selection so that the rotation speed and the rotation angle phase of each polygon mirror PM of the U6 are specified. ), A beam switching control unit that controls on / off (applied / not applied) of the drive signals DF1 to DF6 as ultrasonic signals based on the origin signal SZn (SZ1 to SZ6) (later FIG. 5). More in detail), and. Also in FIG. 4, according to the arrangement of FIG. 1, the beam LB from the light source device LS passes in the order of selection optical element OS5 → OS6 → OS3 → OS4 → OS1 → OS2. Further, in FIG. 4, the selection optical element OS4 among the six selection optical elements OS1 to OS6 is selected and turned on, and the beam LB (drawing data SDn of the pattern drawn by the drawing unit U4) from the light source device LS is turned on. (Intensity modulated by) is deflected toward the incident mirror IM4 and supplied to the drawing unit U4 as a beam LB4.

In this way, when the selection optical elements OS1 to OS6 are provided in series in 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. The intensity of the selected beams LB1 to LB6 (peak intensity of the pulsed light) differs depending on the above. Therefore, the relative difference in the intensities of the beams LB1 to LB6 incident on each of the drawing units U1 to U6 (that is, the exposure amount each of the drawing units U1 to U6 gives to the photosensitive layer of the substrate P) is within a predetermined allowable range (that is, For example, it is necessary to adjust (align) within ± 5%, preferably within ± 2%. In the present embodiment, the intensities of the beams LB1 to LB6 incident on each of the drawing units U1 to U6 are set to the respective levels (high frequency signals) of the drive signals DF1 to DF6 for driving each of the selection optical elements OS1 to OS6. Adjust by changing the amplitude or power of.

Therefore, 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 some points 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. In FIG. 4, the photoelectric sensor DTa (first photoelectric sensor) transmits a beam LB emitted from the light source device LS at a constant ratio (for example, several percent or less) when reflected by the reflection mirror M1 in FIG. It receives the leaking light and outputs a photoelectric signal according to its intensity. The photoelectric signal from the photoelectric sensor DTa is input to the detection circuit CKa including an amplifier, a sample hold circuit, an analog / digital converter, etc., 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. When the light source device LS has a wavelength conversion element, the beam in the long wavelength region before the wavelength conversion may be superimposed on the beam LB in the ultraviolet wavelength region and output. 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 passes through the six selection optical elements OS5, OS6, OS3, OS4, OS1 and OS2 in order. The beam (0th-order light) transmitted through the partially reflected mirror Mb arranged in is received. The partial reflection mirror Mb is a beam that splits the beam (0th-order light) transmitted through the selection optical element OS2 in the final stage into the absorber TR and the photoelectric sensor DTb among the six selection optical elements OS1 to OS6. Acts as a splitter. The photoelectric signal output from the photoelectric sensor DTb is input to the detection circuit CKb including the amplifier, the sample hold circuit, the analog / digital converter, etc., and the detection circuit CKb is the beam passing through the selection optical element OS2 in the final stage ( The 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 that the intensities of the beams received by the photoelectric sensor DTa and the photoelectric sensor DTb are the same when they are the same. It is assumed that it is.

Further, in the present embodiment, the beam LBn (LB1 to LB6) reflected by each of the incident mirrors Imn (IM1 to IM6) and incident on each of the drawing units Un (U1 to U6) is reflected on the back side of the reflection mirror M22. The photoelectric sensors DT1 to DT6 that are arranged and receive the leakage light of the beam LBn in the reflection mirror M22 are provided. The reflective surface of the reflection mirror M22 reflects most of the incident beam LBn (for example, about 98%), but the remaining intensity is transmitted as leaked light. Although not shown in FIG. 4, the photoelectric signals Sm1 to Sm6 from each of the photoelectric sensors DT1 to DT6 are amplified by the same detection circuits as the detection circuits CKa and CKb, respectively, and correspond to the respective intensities of the photoelectric signals Sm1 to Sm6. The measured signal (digital value) is generated. These measurement signals are used for the actual exposure control, but here, for the sake of simplicity, the exposure control is performed based on the respective intensities of the photoelectric signals Sm1 to Sm6. Each intensity of the photoelectric signals Sm1 to Sm6 (measured signal after amplification) corresponds to the absolute intensity of the spot light SP (beams LB1 to LB6) projected on 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 the exposure control (intensity correction) is performed so that the intensities of the photoelectric signals Sm1 to Sm6 are within a predetermined allowable range (for example, within ± 2%), the pattern drawn by each of the drawing units U1 to U6 can be obtained. , It will be exposed with the same exposure amount (dose amount).

FIG. 5 shows an intensity adjustment control unit 250 for controlling the exposure amount in each of the drawing units Un, which is provided in the drawing control device 200 of FIG. 4, and drive signals of the respective optical elements OS1 to OS6 for selection. The configuration with the drive circuits 251a to 251f that generate DF1 to 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 also inputs the detection signals Sa and Sb in the drawing control device 200. Various control information IFDs are exchanged with the main control CPU. Each of the drive circuits 251a to 251f inputs a high frequency signal from the oscillation circuit RF, and the drive signal DF1 is adjusted to an amplitude (power) corresponding 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) for is calculated by calculation and transmitted. 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 of each of the drawing units Un is aligned with the target value indicated by the control information IFD.

Further, the intensity adjustment control unit 250 responds to each of the origin signals SZ1 to SZ6 by using 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). The switching signals LP1 to LP6 for switching to the off state after being turned on are output to the drive circuits 251a to 251f. Each of the drive circuits 251a to 251f switches between an applied state and a non-applied state 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 showing an example of the change characteristic CCa of the diffraction efficiency due to the change of the RF power (amplitude of the high frequency signal) of the drive signal DFn applied to the acoustic optical modulation element 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 of the acoustic-optical modulation element. Diffraction efficiency β increases with an increase in RF power input within the adjustable range ΔKn, reaches the maximum diffraction efficiency (upper limit of the adjustable range ΔKn) at a certain power value Pwm, and then gradually decreases. Have a tendency. The maximum efficiency is 80% or less, although it varies slightly depending on the type of crystal medium of the acoustic-optical modulation element. 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 shown 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 (%). When, 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 0th order light) transmitted without being deflected is It is represented by 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 fluctuates slightly or the temperature of the crystal medium (or quartz) of the selection optical element OSn changes significantly. 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 fluctuates. 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 ejection surface, and the like, and is usually a constant value (for example) that does not fluctuate. , 95%). However, when the beam is passed through a beam in the ultraviolet wavelength region for a long time, the transmittance εn may gradually fluctuate (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 each of the photoelectric sensors DT1 to DT6 shown in FIG. 4 are set corresponding to the appropriate exposure amount. 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 by feedback so that the target value can be suppressed to within ± 2%, for example. be able to. However, when it becomes necessary to change the appropriate exposure amount, the efficiency β of the selection optical element OSn is changed to adjust the intensity of each of the deflected beam LBn, but 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 each of the drawing units U1 to U6 and the adjustable range ΔK1 to ΔK6 of the selection optical elements OS1 to OS6 for adjusting the intensities of the beams LB1 to LB6. It is a graph shown schematically. In FIG. 7, the horizontal axis indicates the intensity and adjustable range of the beam LBn in each of the drawing units U5, U6, U3, U4, U1, and U2 from the left side according to the order in which the beam LB from the light source device LS is supplied. ΔKn (ΔK1 to ΔK6) are arranged side by side. When the six selection optical elements OS1 to OS6 are serially arranged along the optical path of the beam LB as shown in FIG. 4 (FIG. 1), the degree of transmittance εn of the selection optical elements OS1 to OS6 and individual transmission The adjustment state of the efficiency βn differs depending on each of the selection optical elements OS1 to OS6 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 selection optical element OS5 in the front stage closest to the light source device LS determines the intensity of the beam LB at the point where the light source device LS is emitted. Assuming Eo (value measured by the photoelectric sensor DTa), it is represented by E5 = ε5 ・ β5 ・ Eo 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 selection optical element OS2 in the final stage farthest from the light source device LS is the product of the transmittances εn of all the six selection optical elements OS1 to OS6 and the efficiency. By β2, it is represented by E2 = ε5, ε6, ε3, ε4, ε1, ε2, β2, Eo. Assuming that the transmittances εn of each 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 equally, 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 intensities of the beams LB1 to LB6 are set within an allowable range (for example, ± 2%) with respect to the target value, the efficiency of the optical element OS 5 for selection in the first stage 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 selection optical element OS2 in the final stage is approaching the upper limit of the adjustable range ΔK2 (corresponding to the power value Pwm), and the selection optical element OS5 in the front stage is the lower limit of the adjustable range ΔK5 (power). (Corresponding to the value Pwo) is approaching. Therefore, in FIG. 7, when the target values of the intensities of the beams LB1 to LB6 are changed, the upper limit of the adjustable range ΔK2 of the efficiency of the selection optical element OS2 and the adjustable range ΔK5 of the efficiency of the selection optical element OS5 The intensity (exposure amount) between the lower limit and the settable range is limited.

In an actual device, the beam LB from the light source device LS is such that the intensity of the beam LB2 deflected by the selection optical element OS2 in the final stage, which receives the most attenuation, becomes an appropriate exposure amount with respect to the photosensitive layer of the substrate P. The maximum strength (power) of 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, is it possible to change the target value of the intensity within the range in which the intensity (exposure amount) can be set in FIG. Whether or not it is determined by the drawing control device 200 or the intensity adjustment control unit 250. When the new target value of the intensity of the beams LB1 to LB6 corresponding to the appropriate exposure amount to be adjusted is within the range in which the intensity (exposure amount) can be set in FIG. 7, the efficiency βn of each of the selection optical elements 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 in FIG.

If the new target value of the intensity of the beams LB1 to LB6 corresponding to the appropriate exposure amount to be adjusted is out of the range in which the intensity (exposure amount) can be set in FIG. 7, even if the adjustment (correction) is performed as it is, the final value is obtained. If the exposure amount due to the beam LB2 (drawing unit U2) deflected by the stage selection optical element OS2 is insufficient and the target value falls below the intensity (exposure amount) settable range in FIG. 7, it remains as it is. Even if the adjustment (correction) is made, the exposure amount by the beam LB5 (drawing unit U5) deflected by the selection optical element OS5 in the front stage will be exceeded. When a plurality of selection optical elements 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 beam LB may be affected by fluctuations or deterioration of internal members of the light source device LS. When the intensity gradually decreases, the efficiency βn of each of the selection optical elements OSn is increased in order to maintain the intensity of each of the beam LBn at the target value. Therefore, the adjustable range ΔKn of the efficiency βn of each of the selection optical elements OSn shown in FIG. 7 shifts downward relative to the target value. In that 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 reaches the upper limit first. , No further adjustments are possible.

Therefore, in the present embodiment, the intensity change of the beam LB emitted from the light source device LS is sequentially monitored by the drawing control device 200 or the intensity adjustment control unit 250 by the detection signal Sa from the detection circuit CKa shown in FIG. However, the efficiency β2 of the selection optical element OS2 located at the final stage of the selection optical element OSn is particularly maintained so that the appropriate exposure amount (target value in FIG. 7) is maintained regardless of the intensity change. Check whether the change of (RF power) is possible within the adjustable range ΔK2. When possible, the RF power (amplitude) of each drive signal 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. .. In this way, the relationship between the efficiency β2 (RF power) in the selection optical element OS2 in the final stage and the adjustable range ΔK2 is confirmed 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, and as in the first embodiment, the efficiency βn and the transmittance εn are measured, and the fluctuation of the efficiency βn and the fluctuation of the transmittance εn tend to be out of the allowable range. The selection optical element OSn is specified, the relationship between the efficiency βn (RF power) and the adjustable range ΔKn in the selection optical element OSn is confirmed, and the intensities of the beam LBn by each of the drawing units Un are made uniform. Just adjust.

As described above, in the present embodiment, the beam LB is generated by each of the plurality of selection optical elements (acoustic optical modulation elements) OSn provided so that the beam LBs emitted from the light source device LS are sequentially passed through. Adjustable range of efficiency (change in beam intensity) of each selection optical element OSn even if the intensity of the beam LB from the light source device LS decreases when selectively supplying to any of the corresponding drawing units Un. Under ΔKn, the intensities of the beams LBn supplied to each of the drawing units Un are adjusted so that the patterns drawn by each of the drawing units Un have the same exposure (eg within ± 2% tolerance). Be exposed. Therefore, the uniformity of the line width at the joint of the pattern exposed by each of the drawing units Un is maintained.

[Second Embodiment]
In the above embodiment, each of the drawing units Un pays attention to the adjustable range ΔK2 of the efficiency β2 (RF power) in the selection optical element OS2 located at the final stage among the selection optical elements OSn. 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 significantly different, only the adjustable range ΔK2 of the efficiency β2 (RF power) of the selection optical element OS2 in the final stage is focused on as shown in FIG. Instead, it is desirable to determine whether or not a specified appropriate exposure amount (target value of beam LBn intensity) can be obtained from the adjustable range ΔKn of the efficiency βn of all the selection optical elements OSn. For that purpose, it is necessary to grasp the state of fluctuation 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 the present embodiment, the fluctuation of the efficiency βn of each of the selection optical elements OSn is measured by using the detection signals Sa and Sb from each of the photoelectric sensors DTa and DTb shown in FIG.

In FIG. 8, of 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 state of each beam when one selection optical element OS5, OS6, OS4, OS1 and OS2 are turned off. In FIG. 8, since the selection optical element OS3 is in the ON state, the beam LB3z as the 0th-order light traveling in the selection optical element OS3 in a non-biased state is received by the photoelectric sensor DTb and output as a detection signal Sb. Will be done. Here, the intensity of the detection signal Sa corresponding to the intensity of the beam LB received by the photoelectric sensor DTa is set to Ea, and when all the selection optical elements OSn (OS1 to OS6) are in the off state, the photoelectric sensor DTb receives light. When 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 represented by the following equation 1 by the transmittance εn.
Eb0 = ε5 ・ ε6 ・ ε3 ・ ε4 ・ ε1 ・ ε2 ・ Ea ・ ・ ・ (1)
Here, let Kε be the product of the six transmittances ε1 to ε6. In order to acquire the intensity Ea and the intensity Eb0, the drawing control device 200 uses the beam LB when all the selection optical elements OSn are in the off state, that is, during the period when all the drawing units Un do not draw the pattern. The light source device LS is pulsed for a short time so that the light source device LS passes through each of the selection optical elements OSn.

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 selection optical element OS5 in the front stage is in the ON state is the selection optical element OS5. The efficiency β5 is included and it is expressed by the following equation 2.
Eb5 = Kε (1-β5) Ea ・ ・ ・ (2)

Similarly, the intensity Eb6, Eb3 of the detection signal Sb corresponding to the intensity of the 0th-order light received by the photoelectric sensor DTb when each of the selection optical elements OS6, OS3, OS4, OS1, and OS2 is sequentially turned on. , Eb4, Eb1 and Eb2 are represented by the following equations 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 equations 1 to 7, the intensity adjustment control unit 250 having the function of the beam intensity measuring unit has the intensity Ea corresponding to the beam LB received by the photoelectric sensor DTa and the 0th-order light received by the photoelectric sensor DTb. Based on the intensity Ebn (Eb1 to Eb6) corresponding to the beam LBnz of the above, the efficiency βn of each of the selection optical elements OSn at the measurement time point (during the pattern exposure operation) can be obtained by the following equation 8.
βn = 1- (Ebn / Eb0) ・ ・ ・ (8)

Further, during the pattern exposure operation, the intensities of the deflected beams LB1 to LB6 detected by each of the photoelectric sensors DT1 to DT6 shown in FIG. 4 (corresponding to the magnitudes of the photoelectric signals Sm1 to Sm6) are set to Es1 to Es6. Then, based on the measured efficiency βn, the transmittance ε5 of the selection optical element OS5 in the first stage is based on the relationship of Es5 = ε5 ・ β5 ・ Ea.
ε5 = Es5 / (β5 ・ Ea) ・ ・ ・ (9)
Will be.

The transmittance ε6 of the optical element OS6 for selection in the next stage is based on the relationship of Es6 = ε6, ε5, β6, and Ea.
ε6 = Es6 / (ε5 ・ β6 ・ Ea) ・ ・ ・ (10)
Will be.

Since the transmittance ε5 is obtained by Equation 9, when this is substituted into Equation 10, the transmittance ε6 becomes.
ε6 = (β5 ・ Es6) / (β6 ・ Es5) ・ ・ ・ (11)
Will be.

Further, the transmittance ε3 of the selection optical element OS3 in the next stage is based on the relationship of Es3 = ε3, ε6, ε5, β3, and Ea.
ε3 = Es3 / (ε6 ・ ε5 ・ β3 ・ Ea) ・ ・ ・ (12)
Will be.

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

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 each set.
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 of
ε4 = (β3 ・ Es4) / (β4 ・ Es3) ・ ・ ・ (14)
ε1 = (β4 ・ Es1) / (β1 ・ Es4) ・ ・ ・ (15)
ε2 = (β1 ・ Es2) / (β2 ・ Es1) ・ ・ ・ (16)
Will be.

In order to perform such an operation accurately, the measured values of the signals measured by each of the photoelectric sensors DTa, DTb, and DT1 to DT6 are in advance so as to accurately correspond to the absolute value of the intensity of the received beam. It shall be calibrated.

The intensity of the beam LBn from each of the drawing units Un is adjusted to an appropriate exposure amount, and while the pattern is exposed, the efficiency βn of each of the six selection optical elements OSn is as described above. By sequentially measuring the transmittance εn at an appropriate interval, for example, every time when one exposure area on the substrate P is exposed, it is possible to identify the drawing unit Un where the exposure amount may fluctuate. The drive signal DFn of the selection optical element OSn corresponding to the drawing unit Un can be adjusted by the intensity adjustment control unit 250 shown in FIG. 5 so that the fluctuation 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 beam of the 0th-order light of the beam LB that passes through the six selection optical elements OS1 to OS6. By providing a beam intensity measuring unit using a photoelectric sensor DTb for detecting the intensity and a detection circuit CKb, it is possible to easily measure the current efficiencies β1 to β6 of each of the selection optical elements OS1 to OS6 and their fluctuations. Therefore, the efficiency βn fluctuates due to fluctuations in the refractive index due to the thermal influence of each of the selection optical elements OS1 to OS6, slight inclination of the beam optical path due to fluctuations in other optical elements (condensing lens and collimator lens), and the like. The selected optical element OSn for selection can be specified. Further, from the measured fluctuation of the efficiency βn, the adjustable range ΔKn shown in FIG. 7 for correcting the intensity of the beam LBn can be confirmed and reset.

Further, when the photoelectric sensors DT1 to DT6 provided in each of the drawing units U1 to U6 and detecting the intensity of the beams LB1 to LB6 deflected by each of the selection optical elements OS1 to OS6 are used, the selection optical elements OS1 to OS1 to Since the transmittances ε1 to ε6 of each of the OS6s and their fluctuations can be easily measured, the patterns drawn by each of the drawing units U1 to U6 can be accurately maintained at an appropriate exposure amount for exposure. 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 of the selection optical elements OSn can be obtained. Therefore, the intensity of the beam LBn supplied to each of the drawing units Un by the drawing control device 200 or the intensity adjustment control unit 250 can be obtained without using each of the photoelectric sensors DT1 to DT6 provided in the drawing unit Un. 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 used as an acousto-optic modulation element (AOM), and the beam LBn is deflected to each of the drawing units Un by a diffraction effect. The beam LBn may be deflected by using a splitter (polarization separation element). The electro-optical 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 the incident linearly polarized beam by 90 °, whose refractive index changes depending on the applied electric field. Therefore, when the beam emitted from the electro-optical element is incident on the deflection beam splitter, it is possible to switch at high speed between a state of reflecting toward the drawing unit Un according to the polarization direction and a state of transmitting without deflection. In the case of this modification, when the beam from the electro-optical element is reflected toward the drawing unit Un by the deflection beam splitter, the leakage light transmitted through the deflection beam splitter is each of the selection optical elements OSn in the subsequent stage. Since it passes through the electro-optical element and the polarizing 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 ° by the electro-optic element, but is intentionally slightly deviated from 90 °. Therefore, it is advisable to set the applied electric field.

[Modification 2]
In each of the above embodiments, the optical element OSn for switching 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 it is also 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 adjusting member that separately controls the polarization state of the beam LBn to correct the beam intensity for intensity adjustment. As the polarization adjusting member, an electro-optical element (an element that changes the polarization direction by the Pockels effect or the Kerr effect in which the refractive index changes by an electric field) that incidents a linearly polarized beam, and a polarization in a predetermined direction from the beam emitted by the electro-optical element. A combination with a polarizing plate that transmits components can be used. Such a polarization adjusting member may be provided inside each of the drawing units Un, or may be provided only once between the light source device LS and the selection optical element OS 5 in the front stage.

[Modification 3]
Further, when the intensity adjusting member is individually provided, if the fluctuation of the efficiency βn and the transmittance εn of each of the selection optical elements OSn for switching is gradual, the reflection mirror M20 and the reflection mirror in the drawing unit Un of FIG. 2 A glass plate (variable ND filter) having a density distribution so that the transmittance gradually changes is provided in the optical path of the beam LBn magnified by a beam expander (not shown) provided between M20a, and the glass plate is provided. The strength may be adjusted by moving the glass plate so that the transmission position of the beam LBn above is displaced.

[Other variants]
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, but the scanning efficiency of the polygon mirror PM is 1. Depending on / α, the number of light source devices LS is two, and the beam LB from one light source device LS is selectively supplied to, for example, one of three drawing units U1, U3, and U5 having an odd number. The beam LB from the other light source device LS may be controlled so as to selectively supply to any one of the three even-numbered drawing units U2, U4, and U6. Further, the number of drawing units for switching and supplying the beam LB from one light source device LS in a time-division manner is not limited to six or three, and may be two or more. Further, the drawing unit of each embodiment performs beam scanning using a rotating polygon mirror PM, but instead, a galvano mirror (scanning member) that reciprocates around the rotation axis APx within a certain angle range. May be used to scan the beam LBn incident on the fθ lens system FT.

Claims (7)

A pattern drawing device that draws a pattern on a substrate by a plurality of drawing units that scan a beam from a light source device on a substrate by a scanning member to draw a pattern.
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 so as to pass in order, and the beam is supplied by electrical control. A beam switching unit having multiple acoustic-optical modulation elements directed toward the drawing unit,
A beam intensity adjusting unit that adjusts the intensity of a beam projected from a specific drawing unit among the plurality of drawing units onto the substrate, and a beam intensity adjusting unit .
A control unit that controls the beam intensity adjustment unit and
Equipped with
The control unit compares the adjustable range of the efficiency of the plurality of acoustic and optical modulation elements, and adjusts the beam intensity so that the intensities of the beams projected from each of the plurality of drawing units on the substrate are the same. A pattern drawing device to control . The pattern drawing apparatus according to claim 1 .
The beam intensity adjusting unit is a pattern drawing apparatus including a drive circuit that adjusts a drive signal of the acoustic-optical modulation element so as to adjust the efficiency of the acoustic-optical modulation element. The pattern drawing apparatus according to claim 1 or 2 .
In order to measure the efficiency of the plurality of acoustic- optical modulation elements, the control unit detects the intensity of the 0th-order light of the beam from the light source device transmitted through the plurality of the acoustic-optical modulation elements. A pattern drawing device that uses signals from. The pattern drawing apparatus according to any one of claims 1 to 3.
A plurality of beam intensity adjusting units are provided corresponding to each of the plurality of drawing units, and are pattern drawing devices. A pattern drawing device that draws a pattern on the substrate by a plurality of drawing units that scan a beam from a light source device on a substrate with a scanning member to draw a pattern.
An acoustic-optical modulation element for deflecting the beam from the light source device toward the drawing unit is provided corresponding to each of the plurality of drawing units, and the beam from the light source device is provided with the plurality of the acoustic-optical modulation elements. A beam switching unit having a plurality of optical elements that guide light so as to pass through each of them in order, and
A control unit that switches one of the plurality of acoustic and optical modulation elements to a deflection state so that the beam from the light source device is sequentially supplied to one of the plurality of drawing units.
Of the plurality of acoustic and optical modulation elements, the intensity of the beam in the non-deflected state transmitted through the acoustic and optical modulation element in the deflected state is detected, and the beam supplied to each of the plurality of drawing units of the beam. Beam intensity measurement unit that measures intensity and
Equipped with
The beam intensity measuring unit includes a first photoelectric sensor that detects the intensity of a beam from the light source device incident on the acoustic-optical modulation element in the front stage of the plurality of acoustic-optical modulation elements.
A second photoelectric sensor that detects the intensity of the beam in the non-deflected state that has passed through each of the plurality of acoustic and optical modulation elements, and a second photoelectric sensor.
Equipped with
The beam intensity measuring unit converts the photoelectric signal output from the first photoelectric sensor and the second photoelectric sensor each time one of the plurality of acoustic-optical modulation elements is switched to the deflection state by the control unit. Based on this, a pattern drawing device that calculates information regarding the efficiency of each of the plurality of acoustic-optical modulation elements . The pattern drawing apparatus according to claim 5 .
The beam intensity measuring unit includes a plurality of third photoelectric sensors provided so as to receive each of the beams deflected by each of the plurality of acoustic and optical modulation elements and supplied to each of the drawing units. Pattern drawing device. The pattern drawing apparatus according to claim 6 .
The beam intensity measuring unit is based on the photoelectric signals output from each of the second photoelectric sensor and the plurality of third photoelectric sensors and the information regarding the efficiency of each of the plurality of acoustic-optical modulation elements. A pattern drawing device that calculates information regarding the transmittance of the plurality of acoustic-optical modulation elements.

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