JP2019197219A - Pattern drawing device - Google Patents

Abstract

To provide a pattern drawing device that does not degrade overlay accuracy and total pitch accuracy.SOLUTION: A pattern drawing device includes: a rotary polygon mirror PM; an origin sensor OP1 that generates an origin pulse signal expressing a drawing start time point due to a light beam LB1 every time when each reflective surface of the rotary polygon mirror PM becomes a predetermined angular position; a data storage part that stores pixel data corresponding to each of a plurality of pixels as a pixel data sequence arranged in a scanning order of spots when a pattern to be drawn on a substrate is expressed with a plurality of pixels decomposed in two dimensions of a main scanning direction and a sub-scanning direction; and a controller that starts a drawing operation due to spots based on the pixel data sequence prepared and treated responding to a second origin pulse signal by executing the preparation treatment that performs indicated and predetermined calculation of the pixel data sequence to be drawn stored in the data memory part by the time of generation of a next second origin pulse signal corresponding to the first origin pulse signal.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a pattern drawing apparatus that draws a pattern by irradiating a light beam based on drawing data onto an object to be irradiated such as a substrate.

  In recent years, printing methods such as intaglio printing, letterpress printing, silk printing, or ink jet printing on flexible substrates made of resin or ultra-thin glass, called “printable electronic”, or flexible printing. Attempts have been made to form electronic devices such as display displays by an optical patterning method in which an ultraviolet light pattern is projected onto a photosensitive layer coated on a substrate. As an electronic device, a circuit pattern (single wiring layer or multilayer wiring layer) including a thin film transistor (TFT), an IC chip, a sensor element, a resistance element, a capacitor element, etc. is formed with a high pattern drawing resolution. Since accurate positioning accuracy is required, use of an optical patterning method instead of a printing method is being studied.

  In Patent Document 1 shown below, a laser beam is irradiated onto a substrate in accordance with drawing data defined by a predetermined inter-pixel pitch (pixel size), and the beam and the substrate are relatively two-dimensionally moved. A pattern forming apparatus for forming a pattern such as a TFT or a color filter on a substrate is disclosed. In the pattern forming apparatus of Patent Document 1, each position of alignment marks formed at a plurality of positions around a previous process pattern formed on a base material (flexible base material) is detected, and based on the result, the base material is detected. The pattern exposure is performed in which the positional deviation from the previous process pattern is prevented by calculating the expansion / contraction (and deformation) and correcting the drawing data according to the calculated expansion / contraction (deformation). When correcting the drawing data, the pixel dimensions (pixels) subdivided into the direction of moving the beam on the substrate (main scanning direction) and the moving direction of the moving stage that supports the substrate (sub-scanning direction) Pitch) is corrected according to the expansion and contraction of the base material.

  However, for example, when a pattern is continuously formed on a long base material by a roll-to-roll system, the expansion and contraction of the base material in the longitudinal direction is not constant and may vary in some places. That is, even in a pattern formation region (exposure region) corresponding to one electronic device formed on a long base material, expansion and contraction in the sub-scanning direction may not be constant. In order to avoid degrading the overlay accuracy with the base pattern (pre-process pattern) and the total pitch accuracy (dimensional accuracy of the entire pattern formation region) even while the pattern is being drawn in one pattern formation region, There arises a need to finely change the magnification correction in the scanning direction.

JP 2004-272167 A

  A first aspect of the present invention includes an exposure head unit that scans a spot of a light beam modulated based on drawing data in the main scanning direction on the substrate, and moves the substrate in the sub-scanning direction. A pattern drawing apparatus for drawing a pattern corresponding to the drawing data on the substrate, wherein the rotating polygon mirror which sequentially reflects the light beam on each of a plurality of reflecting surfaces and scans in a main scanning direction; and the rotating polygon An origin sensor that generates an origin pulse signal indicating a drawing start time by the light beam every time each reflecting surface of the mirror reaches a predetermined angular position, and the pattern to be drawn on the substrate in the main scanning direction and the pattern A pixel data sequence in which pixel data corresponding to each of the plurality of pixels is arranged in the order of scanning of the spot when represented by a plurality of pixels decomposed two-dimensionally in the sub-scanning direction And the data storage unit to be stored and the data to be drawn stored in the data storage unit until the next generation of the origin pulse signal in response to the first origin pulse signal A preparatory process for specifying a pixel data string and performing a predetermined calculation is executed, and in response to the second origin pulse signal, a drawing operation by the spot is started based on the pixel data string that has been subjected to the preparatory process. A control unit.

  According to a second aspect of the present invention, there is provided a pattern drawing apparatus that draws a pattern for an electronic device on a long sheet substrate that is supported in a cylindrical shape on the outer peripheral surface of a rotating drum that rotates about a central axis. A scanning unit that repeatedly scans a drawing beam for drawing the pattern in a main scanning direction substantially parallel to a direction in which the central axis extends on the sheet substrate by a rotating polygon mirror, and the sheet substrate At the time when the rotation driving source for rotating the rotary drum and the drawing beam correspond to the scanning start position in the main scanning direction so as to move at a predetermined conveying speed in the sub-scanning direction intersecting the main scanning direction. A detection sensor that outputs a detection signal indicating that the rotation has occurred for each of the plurality of reflecting surfaces of the rotary polygon mirror, and a pattern to be drawn while the drawing beam is scanned in the main scanning direction. A period between a data storage unit that stores a plurality of corresponding drawing data in the sub-scanning direction, the first detection signal output from the detection sensor, and the second detection signal output thereafter In addition, a preparation process for reading out and preparing the drawing data to be drawn in response to the second detection signal from the data storage unit is performed, and the preparation process is performed in response to the second detection signal. And a control unit that controls to perform drawing of the pattern by the drawing beam based on the drawing data.

It is a figure which shows the whole structure of the exposure apparatus by 1st Embodiment. FIG. 2 is a detailed view showing a state in which a substrate is wound around a rotating drum of the exposure apparatus shown in FIG. 1. It is a figure which shows the drawing line of the spot light scanned on a board | substrate, and the alignment mark formed on the board | substrate. It is a figure which shows the optical structure of the scanning unit shown in FIG. It is a figure which shows the structure of the beam distribution part shown in FIG. It is a block diagram which shows schematic structure of the control apparatus shown in FIG. It is a figure which shows the specific structure of the light source device shown in FIG. FIG. 7 is a diagram for explaining the timing of reading of drawing data (pixel data string) corresponding to the movement position (movement amount) of the substrate by the drawing control unit and the drawing data storage unit shown in FIG. 6. FIG. 9A is a diagram showing a state in which the increment of the X address value (increase of the first address) corresponds to 10 counts of the movement amount when the magnification correction is not performed, and FIG. 9B shows the pattern to be drawn. In order to reduce, it is a figure which shows the state where the increment of X address value (increase of 1 address) respond | corresponds to 9 counts of movement amount. It is a figure explaining the control at the time of changing to a different drawing magnification in the middle of drawing operation. It is a figure explaining the control at the time of changing to a different drawing magnification in the middle of drawing operation. It is a figure explaining an example of the magnification change point set on one exposure area. 7 is a time chart for explaining a modified example of a calculation sequence for correcting a drawing magnification in the sub-scanning direction, which is executed by the drawing control unit shown in FIG. 6. 6 is a time chart showing the generation timing, drawing timing, and calculation timing of the origin signal from the scanning unit in time series. FIG. 15 is a block diagram illustrating an outline of a part of the circuit configuration provided in each of the drawing control unit and the drawing data storage unit in FIG. 6 in order to perform the control described in FIG. 14. FIG. 16 is a chart illustrating an example of a case where the position shift of the drawing pattern in the main scanning direction (Y direction) described in FIGS. 14 and 15 is continuously performed during the pattern drawing operation for the exposure region.

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

[First Embodiment]
FIG. 1 is a diagram showing a schematic configuration of a device manufacturing system 10 including an exposure apparatus (pattern drawing 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 orthogonal coordinate system in which the gravity direction is the Z direction is set, and the X direction, the Y direction, and the Z direction will be described according to the arrows shown in the drawing.

  The device manufacturing system 10 is a system (substrate processing apparatus) that manufactures an electronic device by performing predetermined processing (such as exposure processing) on the substrate P. In the device manufacturing system 10, for example, a manufacturing line for manufacturing a flexible display as an electronic device, a film-like touch panel, a film-like color filter for a liquid crystal display panel, a flexible wiring, or a flexible sensor is constructed. It is a manufacturing system. The following description is based on the assumption that a flexible display is used as the electronic device. Examples of the flexible display include an organic EL display and a liquid crystal display. The device manufacturing system 10 sends a substrate P from a supply roll (not shown) obtained by winding a flexible sheet-like substrate (sheet substrate) P in a roll shape, and continuously performs various processes on the sent substrate P. After the application, the substrate P after various treatments is wound up by a collection roll (not shown), and has a so-called roll-to-roll structure. The substrate P has a belt-like shape in which the moving direction (transport direction) of the substrate P is the longitudinal direction (long) and the width direction is the short direction (short). In the first embodiment, the film-like substrate P passes through the pre-processing apparatus (first processing apparatus) PR1, the exposure apparatus EX, and the post-processing apparatus (second processing apparatus) PR2. An example of continuous processing is shown.

  In the first embodiment, the X direction is a horizontal plane parallel to the floor E of the factory where the apparatus is installed and the substrate P is transported, and the Y direction is the X direction in the horizontal plane. , That is, the width direction (short direction) of the substrate P, and the Z direction is a direction (upward direction) orthogonal to the X direction and the Y direction, and is parallel to the direction in which gravity acts.

  As the substrate P, for example, a resin film or a foil (foil) made of a metal or alloy such as stainless steel is used. Examples of the resin film material include polyethylene resin, polypropylene resin, polyester resin, ethylene vinyl copolymer resin, polyvinyl chloride resin, cellulose resin, polyamide resin, polyimide resin, polycarbonate resin, polystyrene resin, and vinyl acetate resin. Of these, one containing at least one or more may be used. Further, the thickness and rigidity (Young's modulus) of the substrate P may be in a range that does not cause folds or irreversible wrinkles due to buckling in the substrate P when passing through the conveyance path of the device manufacturing system 10. . As a base material of the substrate P, a film such as PET (polyethylene terephthalate) or PEN (polyethylene naphthalate) having a thickness of about 25 μm to 200 μm is typical of a suitable sheet substrate.

  Since the substrate P may receive heat in each process performed by the processing apparatus PR1 and the processing apparatus PR2, it is preferable to select the substrate P made of a material that does not have a significantly large thermal expansion coefficient. For example, the thermal expansion coefficient can be suppressed by mixing an inorganic filler with a resin film. The inorganic filler may be, for example, titanium oxide, zinc oxide, alumina, or silicon oxide. The substrate P may be a single layer of ultrathin glass having a thickness of about 100 μm manufactured by a float process or the like, or a laminate in which the above resin film, foil, or the like is bonded to the ultrathin glass. It may be.

  By the way, the flexibility of the substrate P means the property that the substrate P can be bent without being sheared or broken even when a force of its own weight is applied to the substrate P. . In addition, flexibility includes a property of bending by a force of about its own weight. The degree of flexibility varies depending on the material, size and thickness of the substrate P, the layer structure formed on the substrate P, the environment such as temperature or humidity, and the like. In any case, when the substrate P is correctly wound around the conveyance direction changing members such as various conveyance rollers and rotary drums provided in the conveyance path in the device manufacturing system 10 according to the first embodiment, If the substrate P can be smoothly transported without being bent and creased or damaged (breaking or cracking), it can be said to be a flexible range.

  The pre-process processing apparatus PR1 is a coating apparatus that performs a coating process and a drying process on the substrate P while transporting the substrate P along the longitudinal direction at a predetermined speed. After the photosensitive functional liquid is selectively or uniformly applied to the surface of the substrate P, the processing apparatus PR1 removes the solvent or water contained in the photosensitive functional liquid and dries the photosensitive functional liquid. Thereby, a film to be a photosensitive functional layer (photosensitive layer) is selectively or uniformly formed on the surface of the substrate P. Note that the photosensitive functional layer may be formed on the surface of the substrate P by attaching a dry film to the surface of the substrate P. In this case, instead of the processing apparatus PR1, a pasting apparatus (processing apparatus) for attaching the dry film to the substrate P may be provided.

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

  The exposure apparatus EX performs exposure processing (pattern drawing) on the substrate P while transporting the substrate P transported from the processing apparatus PR1 toward the processing apparatus PR2 in the transport direction (+ X direction) at a predetermined speed. It is a processing device. The exposure apparatus EX uses a light corresponding to a pattern for an electronic device (for example, a pattern of an electrode or wiring of a TFT 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 pattern. Thereby, a latent image (modified portion) corresponding to the pattern is formed on the photosensitive functional layer.

  In the first embodiment, the exposure apparatus EX is a direct drawing type exposure apparatus that does not use a mask, that is, a so-called raster scan type pattern drawing apparatus. As will be described in detail later, the exposure apparatus EX, while transporting the substrate P in the longitudinal direction (sub-scanning direction), emits a spot beam SP of a pulsed beam (pulse beam, light beam) LB for exposure, The intensity of the spot light SP is modulated at high speed according to the pattern data (drawing data) while one-dimensionally scanning (main scanning) in the predetermined scanning direction (Y direction) on the irradiated surface (photosensitive surface) of the substrate P. (ON / OFF). Thereby, a light pattern corresponding to a predetermined pattern such as an electronic device, a circuit, or a wiring is drawn and exposed on the irradiated surface of the substrate P. That is, the spot light SP is relatively two-dimensionally scanned on the irradiated surface of the substrate P by the sub-scanning of the substrate P and the main scanning of the spot light SP, and a predetermined pattern is drawn and exposed on the substrate P. . Further, since the substrate P is transported along the longitudinal direction, a plurality of exposure regions W where the pattern is exposed by the exposure apparatus EX are provided at predetermined intervals along the longitudinal direction of the substrate P. (See FIG. 3). Since an electronic device is formed in the exposure area W, the exposure area W is also a device formation area.

  The post-process processing apparatus PR2 is a wet processing apparatus that performs wet processing and drying processing on the substrate P while transporting the substrate P transported from the exposure apparatus EX at a predetermined speed. In the first embodiment, the processing apparatus PR2 performs a development process or a plating process which is a kind of wet process on the substrate P. Therefore, the processing apparatus PR2 includes a developing unit that immerses the substrate P in the developer for a predetermined time, a plating unit that immerses the substrate P in the electroless plating solution for a predetermined time, and a cleaning unit that cleans the substrate P with pure water or the like. And a drying unit for drying the substrate P. As a result, a pattern layer corresponding to the latent image is deposited (formed) on the surface of the photosensitive functional layer. That is, a predetermined material (for example, resist, palladium) is selectively formed on the substrate P according to the difference between the irradiated portion and the non-irradiated portion of the spot light SP on the photosensitive functional layer of the substrate P, and this is the pattern. Become a layer.

  When a photosensitive silane coupling agent is used as the photosensitive functional layer, a coating process or a plating process of a liquid (for example, a liquid containing a conductive ink or the like) as a wet process is performed by the processing apparatus PR2. Is called. Even in this case, a pattern layer corresponding to the latent image is formed on the surface of the photosensitive functional layer. That is, a predetermined material (for example, conductive ink or palladium) is selectively formed on the substrate P according to the difference between the irradiated portion of the spot light SP of the photosensitive functional layer of the substrate P and the irradiated portion, This is the pattern layer.

  Now, the exposure apparatus (pattern drawing apparatus) EX shown in FIG. 1 is stored in the temperature control chamber ECV. This temperature control chamber ECV keeps the inside at a predetermined temperature and a predetermined humidity, thereby suppressing a change in shape due to the temperature of the substrate P transported inside, and occurring along with the hygroscopicity and transport of the substrate P. The humidity is set in consideration of static charge. The temperature control chamber ECV is arranged on the floor E of the manufacturing plant via passive or active vibration isolation units SU1, SU2. The anti-vibration units SU1 and SU2 reduce vibration from the floor surface E. This floor surface E may be the floor surface of the factory itself, or may be a surface on an installation base (pedestal) that is exclusively installed on the floor surface in order to obtain a horizontal surface. The exposure apparatus EX includes a substrate transport mechanism 12, a light source device LS, a beam distribution unit BDU, an exposure head 14, a control device 16, and a plurality of alignment microscopes AM1m and AM2m (m = 1, 2, 3, 4) and a plurality of encoder heads ENja, ENjb (j = 1, 2, 3, 4). The control device (control unit) 16 controls each part of the exposure apparatus EX. The control device 16 includes a computer, a recording medium on which a program is recorded, and the like, and functions as the control device 16 of the first embodiment when the computer executes the program.

  The substrate transport mechanism (moving mechanism) 12 constitutes a part of the substrate transport apparatus of the device manufacturing system 10, and transports the substrate P transported from the processing apparatus PR1 at a predetermined speed in the exposure apparatus EX. Then, it sends out to the processing apparatus PR2 at a predetermined speed. The substrate transport mechanism 12 defines a transport path for the substrate P transported in the exposure apparatus EX. The substrate transport mechanism 12 includes an edge position controller EPC, a driving roller R1, a tension adjusting roller RT1, a rotating drum (cylindrical drum) DR, a tension adjusting roller RT2, in order from the upstream side (−X direction side) in the transport direction of the substrate P. A driving roller R2 and a driving roller R3 are provided.

  In the edge position controller EPC, the position in the width direction (Y direction and the short direction of the substrate P) of the substrate P transported from the processing apparatus PR1 is within a range of about ± 10 to several tens μm with respect to the target position. The position of the substrate P in the width direction is adjusted by moving the substrate P in the width direction so as to fall within (allowable range). The edge position controller EPC finely moves the roller of the edge position controller EPC in the Y direction on the basis of a detection signal from an edge sensor (not shown) that detects the position of the edge (edge) in the width direction of the substrate P. The position of P in the width direction is adjusted. The driving roller (nip roller) R1 rotates while holding both front and back surfaces of the substrate P conveyed from the edge position controller EPC, and conveys the substrate P toward the rotating drum DR. The edge position controller EPC appropriately adjusts the position in the width direction of the substrate P so that the longitudinal direction of the substrate P wound around the rotating drum DR is always perpendicular to the central axis AXo of the rotating drum DR. The parallelism between the rotation axis of the roller and the Y axis of the edge position controller EPC may be appropriately adjusted so as to correct the tilt error in the traveling direction of the substrate P.

  The rotating drum DR has a central axis AXo extending in the Y direction and extending in a direction intersecting with the direction in which gravity works, and a cylindrical outer peripheral surface having a constant radius from the central axis AXo. The rotating drum DR rotates around the central axis AXo while supporting (holding) a part of the substrate P by bending the outer surface (circumferential surface) into a cylindrical surface in the longitudinal direction. Transport P in the + X direction. The rotating drum DR supports an area (portion) on the substrate P onto which the beam LB (spot light SP) from the exposure head 14 is projected on the outer peripheral surface thereof. The rotating drum DR supports (holds and holds) the substrate P from the surface (back surface) opposite to the surface (surface on which the photosensitive layer is formed) on which the electronic device is formed. On both sides in the Y direction of the rotating drum DR, shafts Sft supported by annular bearings are provided so that the rotating drum DR rotates around the central axis AXo. The shaft Sft rotates at a constant rotational speed around the central axis AXo by receiving a rotational torque from a rotational drive source (not shown) (for example, a motor or a speed reduction mechanism) controlled by the control device 16. For convenience, a plane including the central axis AXo and parallel to the YZ plane is referred to as a central plane Poc.

  The drive rollers (nip rollers) R2 and R3 are arranged at a predetermined interval along the transport direction (+ X direction) of the substrate P, and give a predetermined slack (play) to the substrate P after exposure. Similarly to the drive roller R1, the drive rollers R2 and R3 rotate while holding both front and back surfaces of the substrate P, and convey the substrate P toward the processing apparatus PR2. The tension adjusting rollers RT1 and RT2 are urged in the −Z direction, and apply a predetermined tension in the longitudinal direction to the substrate P that is wound around and supported by the rotary drum DR. As a result, the longitudinal tension applied to the substrate P applied to the rotating drum DR is stabilized within a predetermined range. The control device 16 rotates the drive rollers R1 to R3 by controlling a rotation drive source (not shown) (for example, a motor, a speed reduction mechanism, etc.). The rotation axes of the drive rollers R1 to R3 and the rotation axes of the tension adjustment rollers RT1 and RT2 are parallel to the central axis AXo of the rotation drum DR.

  The light source device LS generates and emits a pulsed beam (pulse beam, pulsed light, laser) LB. This beam LB is ultraviolet light having a peak wavelength at a specific wavelength (for example, 355 nm) in a wavelength band of 370 nm or less, and the light emission frequency (oscillation frequency, predetermined frequency) of the beam LB is Fa. The beam LB emitted from the light source device LS enters the exposure head 14 via the beam distribution unit BDU. The light source device LS emits and emits the beam LB at the emission frequency Fa according to the control of the control device 16. Although the configuration of the light source device LS will be described in detail later, in the first embodiment, a semiconductor laser element that generates pulsed light in the infrared wavelength region, a fiber amplifier, an amplified infrared wavelength region It is composed of a wavelength conversion element (harmonic generation element) that converts pulsed light into pulsed light in the ultraviolet wavelength region, and can emit pulses at an oscillation frequency Fa of 100 MHz to several hundreds of MHz. It is assumed that a fiber amplifier laser light source (harmonic laser light source) capable of obtaining high-intensity ultraviolet pulsed light of about several picoseconds to several tens of picoseconds is used.

  The beam distribution unit BDU includes a plurality of mirrors and beams that distribute the beam LB from the light source device LS to each of the plurality of scanning units Un (n = 1, 2,..., 6) constituting the exposure head 14. A splitter and a drawing optical element (AOM) that modulates the intensity of each beam LBn incident on each scanning unit Un according to drawing data are described in detail later with reference to FIG.

  The exposure head (exposure head unit) 14 is a so-called multi-beam type exposure head in which a plurality of scanning units Un (U1 to U6) having the same configuration are arranged. The exposure head 14 draws a pattern on a part of the substrate P supported by the outer peripheral surface (circumferential surface) of the rotary drum DR by a plurality of scanning units Un (U1 to U6). Since the exposure head 14 repeatedly performs pattern exposure for an electronic device on the substrate P, an exposure region (electronic device formation region) W where the pattern is exposed is a longitudinal direction of the substrate P as shown in FIG. Are provided at predetermined intervals. The plurality of scanning units Un (U1 to U6) are arranged in a staggered arrangement in two rows in the transport direction of the substrate P with the center plane Poc interposed therebetween. The odd-numbered scanning units U1, U3, U5 are arranged in a line on the upstream side (−X direction side) in the transport direction of the substrate P with respect to the center plane Poc and at a predetermined interval along the Y direction. Has been placed. The even-numbered scanning units U2, U4, U6 are arranged in a line at a predetermined interval along the Y direction on the downstream side (+ X direction side) in the transport direction of the substrate P with respect to the center plane Poc. Yes. The odd-numbered scanning units U1, U3, and U5 and the even-numbered scanning units U2, U4, and U6 are provided symmetrically with respect to the center plane Poc when viewed in the XZ plane.

  Each scanning unit Un (U1 to U6) projects the beam LBn (n = 1 to 6) supplied from the beam distribution unit BDU so as to converge on the spot light SP on the irradiated surface of the substrate P. The spot light SP is scanned one-dimensionally by a rotating polygon mirror PM (see FIG. 4). The spot light SP is one-dimensionally scanned in the Y direction on the irradiated surface of the substrate P by the polygon mirror PM of each scanning unit Un (U1 to U6). By scanning with the spot light SP, a linear drawing line (scanning line) SLn on which a pattern for one line is drawn on the substrate P (on the irradiated surface of the substrate P) (n = 1, 2, ..., 6) are defined.

  The scanning unit U1 scans the spot light SP along the drawing line SL1, and similarly, the scanning units U2 to U6 scan the spot light SP along the drawing lines SL2 to SL6. The drawing lines SL1 to SL6 of the plurality of scanning units U1 to U6 are separated in the sub-scanning direction, which is the long direction of the substrate P, as shown in FIG. 2 and FIG. However, the Y direction (the width direction of the substrate P or the main scanning direction) is set to be joined without being separated from each other. In the beam LBn emitted from the beam distribution unit BDU, the beam incident on the scanning unit U1 is represented by LB1, and similarly, the beam LBn incident on the scanning units U2 to U6 is represented by LB2 to LB6. The beam LBn incident on the scanning unit Un may be a linearly polarized light (P-polarized light or S-polarized light) polarized in a predetermined direction, or a circularly polarized beam.

  As shown in FIG. 3, the plurality of scanning units U <b> 1 to U <b> 6 are arranged so as to cover all of the exposure region W in the width direction. Thereby, each scanning unit U1-U6 can draw a pattern for every some area | region (drawing range) divided | segmented in the width direction of the board | substrate P. FIG. For example, when the scanning length in the Y direction (the length of the drawing line SLn) by one scanning unit Un is about 20 to 60 mm, three odd numbered scanning units U1, U3, U5 and even numbered scanning unit U2 are used. , U4, and U6, a total of six scanning units Un, which are arranged in the Y direction, expand the width in the Y direction that can be drawn up to about 120 to 360 mm. In principle, the lengths of the drawing lines SL1 to SL6 (the length of the drawing range) are the same. That is, in principle, the scanning distance of the spot light SP of the beam LBn scanned along each of the drawing lines SL1 to SL6 is the same. If it is desired to further increase the width of the exposure region W (the width of the substrate P), it is possible to increase the length of the drawing line SLn itself or increase the number of scanning units Un arranged in the Y direction. it can.

  Each actual drawing line SLn (SL1 to SL6) is set slightly shorter than the maximum length (maximum scanning length) that the spot light SP can actually scan on the irradiated surface. For example, if the scanning length of the drawing line SLn on which pattern drawing is possible is 30 mm when the drawing magnification in the main scanning direction (Y direction) is an initial value (no magnification correction), the maximum scanning on the irradiated surface of the spot light SP is performed. The length is set to about 31 mm with a margin of about 0.5 mm on each of the drawing start point (scanning start point) side and the drawing end point (scanning end point) side of the drawing line SLn. With this setting, the position of the 30 mm drawing line SLn can be finely adjusted in the main scanning direction and the drawing magnification can be finely adjusted within the maximum scanning length of 31 mm of the spot light SP. Become. The maximum scanning length of the spot light SP is not limited to 31 mm, but is determined mainly by the aperture of the fθ lens FT (see FIG. 4) provided after the polygon mirror (rotating polygon mirror) PM in the scanning unit Un.

  The plurality of drawing lines SL1 to SL6 are arranged in a staggered arrangement in two rows in the circumferential direction of the rotary drum DR, with the center plane Poc interposed therebetween. The odd-numbered drawing lines SL1, SL3, and SL5 are located on the irradiated surface of the substrate P on the upstream side (−X direction side) in the transport direction of the substrate P with respect to the center plane Poc. 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) in the transport direction of the substrate P with respect to the center plane Poc. The drawing lines SL1 to SL6 are substantially parallel to the width direction of the substrate P, that is, the central axis AXo of the rotary drum DR.

  The drawing lines SL1, SL3, SL5 are arranged in a line on a straight line at a predetermined interval along the width direction (main scanning direction) of the substrate P. Similarly, the drawing lines SL2, SL4, and SL6 are arranged in a line on the straight line at a predetermined interval along the width direction (main scanning direction) of the substrate P. At this time, the drawing line SL2 is arranged between the drawing line SL1 and the drawing line SL3 in the width direction of the substrate P. Similarly, the drawing line SL3 is arranged between the drawing line SL2 and the drawing line SL4 in the width direction of the substrate P. The drawing line SL4 is arranged between the drawing line SL3 and the drawing line SL5 with respect to the width direction of the substrate P, and the drawing line SL5 is arranged between the drawing line SL4 and the drawing line SL6 with respect to the width direction of the substrate P. Has been.

  The main scanning direction of the spot light SP by each of the beams LB1, LB3, and LB5 scanned along the odd-numbered drawing lines SL1, SL3, and SL5 is a one-dimensional direction and is the same direction. Yes. The main scanning direction of the spot light SP by the beams LB2, LB4, and LB6 scanned along the even-numbered drawing lines SL2, SL4, and SL6 is a one-dimensional direction and is the same direction. Yes. The main scanning direction of the spot light SP of the beams LB1, LB3, LB5 scanned along the drawing lines SL1, SL3, SL5 and the beams LB2, LB4, LB6 scanned along the drawing lines SL2, SL4, SL6. The main scanning direction of the spot light SP may be opposite to each other. In the first embodiment, the main scanning direction of the spot light SP of the beams LB1, LB3, and LB5 scanned along the drawing lines SL1, SL3, and SL5 is the -Y direction. The main scanning direction of the spot light SP of the beams LB2, LB4, and LB6 scanned along the drawing lines SL2, SL4, and SL6 is the + Y direction. Thereby, the drawing start point side ends of the drawing lines SL1, SL3, SL5 and the drawing start point side ends of the drawing lines SL2, SL4, SL6 are adjacent or partially overlapped in the Y direction. Further, the end of the drawing lines SL3 and SL5 on the drawing end point side and the end of the drawing lines SL2 and SL4 on the drawing end point side are adjacent or partially overlap in the Y direction. When arranging each drawing line SLn so that the ends of the drawing lines SLn adjacent in the Y direction partially overlap, for example, the drawing start point or the drawing end with respect to the length of each drawing line SLn It is preferable to overlap within a range of several percent or less in the Y direction including points. Note that joining the drawing lines SLn in the Y direction means that the ends of the drawing lines SLn are adjacent to each other or partially overlap in the Y direction. That is, it means that the patterns drawn by each of the two drawing lines SLn adjacent to each other in the Y direction are joined and exposed in the Y direction.

Note that the width in the sub-scanning direction (dimension in the X direction) of the drawing line SLn is a thickness corresponding to the effective size (diameter) φ of the spot light SP on the substrate P. For example, when the effective size (dimension) φ of the spot light SP is 3 μm, the width of the drawing line SLn is also 3 μm. Further, in the case of the first embodiment, since the beam LB from the light source device LS is pulsed light, the spot light SP projected on the drawing line SLn during the main scanning is the oscillation frequency Fa of the beam LB. It becomes discrete according to (for example, 100 MHz). Therefore, it is necessary to overlap the spot light SP projected by one pulse light of the beam LBn from the beam distribution unit BDU 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 φ of the spot light SP is determined by 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.

  In the first embodiment, the scanning speed Vs and the oscillation frequency Fa of the spot light SP are set so that the spot light SP overlaps by about φ × ½ with respect to the effective size (dimension) φ. Is done. Therefore, the projection interval of the spot light SP along the main scanning direction is φ / 2. Therefore, also in the sub-scanning direction (direction orthogonal to the drawing line SLn), the substrate P is effective for the spot light SP between one scanning of the spot light SP along the drawing line SLn and the next scanning. It is desirable to set so as to move by a distance that is approximately ½ of a large size φ. The exposure amount to the photosensitive functional layer on the substrate P can be set by adjusting the peak value of the beam LB (pulse light). However, the exposure amount can be increased in a situation where the intensity of the beam LB cannot be increased. In the case where the spot light SP is desired, the spot light SP is caused to fall by the decrease in the scanning speed Vs of the spot light SP in the main scanning direction, the increase in the oscillation frequency Fa of the beam LB, or the decrease in the transport speed Vt of the substrate P in the sub-scanning direction. The overlap amount in the main scanning direction or the sub scanning direction may be increased. The scanning speed Vs of the spot light SP in the main scanning direction increases in proportion to the number of rotations (rotation speed Vp) of the polygon mirror PM.

  Each scanning unit Un (U1 to U6) irradiates each beam LBn toward the substrate P so that each beam LBn travels toward the central axis AXo of the rotary drum DR at least in the XZ plane. Thereby, the optical path (beam central axis) of the beam LBn traveling from each scanning 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, each scanning unit Un (U1 to U6) is configured such that the beam LBn irradiated to the drawing line SLn (SL1 to SL6) is perpendicular to the irradiated surface of the substrate P in a plane parallel to the YZ plane. The beam LBn is irradiated toward the substrate P. That is, the beam LBn (LB1 to LB6) projected onto the substrate P is scanned in a telecentric state with respect to the main scanning direction of the spot light SP on the irradiated surface. Here, a line perpendicular to the irradiated surface of the substrate P (also referred to as an optical axis) through each midpoint of a predetermined drawing line SLn (SL1 to SL6) defined by each scanning unit Un (U1 to U6). Is referred to as the irradiation center axis Len (Le1 to Le6).

  Each irradiation center axis Len (Le1 to Le6) is a line connecting the drawing lines SL1 to SL6 and the center axis AXo on the XZ plane. The irradiation center axes Le1, Le3, Le5 of the odd-numbered scanning units U1, U3, U5 are in the same direction on the XZ plane, and the irradiation center axes Le2 of the even-numbered scanning units U2, U4, U6. , Le4 and Le6 are in the same direction in the XZ plane. Further, the irradiation center axes Le1, Le3, Le5 and the irradiation center axes Le2, Le4, Le6 are set such that the angle is ± θ1 with respect to the center plane Poc in the XZ plane (see FIG. 1).

  A plurality of alignment microscopes AM1m (AM11 to AM14) and AM2m (AM21 to AM24) shown in FIG. 1 detect a plurality of alignment marks (marks) MKm (MK1 to MK4) formed on the substrate P shown in FIG. Therefore, a plurality (four in the first embodiment) are provided along the Y direction. The plurality of alignment marks MKm (MK1 to MK4) are reference marks for relatively aligning (aligning) the predetermined pattern drawn in the exposure area W on the irradiated surface of the substrate P with the substrate P. It is. The plurality of alignment microscopes AM1m (AM11 to AM14) and AM2m (AM21 to AM24) are arranged on the substrate P supported by the outer peripheral surface (circumferential surface) of the rotary drum DR, and a plurality of alignment marks MKm (MK1 to MK4). Is detected. The plurality of alignment microscopes AM1m (AM11 to AM14) is more than the irradiated area (area surrounded by the drawing lines SL1 to SL6) on the substrate P by the spot light SP of the beam LBn (LB1 to LB6) from the exposure head 14. It is provided on the upstream side (−X direction side) in the transport direction of the substrate P. Further, the plurality of alignment microscopes AM2m (AM21 to AM24) are irradiated from the exposure head 14 by the spot light SP of the beam LBn (LB1 to LB6) on the substrate P (region surrounded by the drawing lines SL1 to SL6). Is also provided on the downstream side (+ X direction side) in the transport direction of the substrate P.

  The alignment microscopes AM1m (AM11 to AM14) and AM2m (AM21 to AM24) are a local region (observation region) Vw1m (Vw11) including a light source that projects illumination light for alignment onto the substrate P and an alignment mark MKm on the surface of the substrate P. To Vw14), an observation optical system (including an objective lens) for obtaining magnified images of Vw2m (Vw21 to Vw24), and while the substrate P is moving in the transport direction, the substrate P is moved at the transport speed Vt. And an image pickup device such as a CCD or a CMOS for picking up an image with a corresponding high-speed shutter. Imaging signals (image data) captured by each of the plurality of alignment microscopes AM1m (AM11 to AM14) and AM2m (AM21 to AM24) are sent to the control device 16. The control device 16 is provided with a mark position detection unit, and detects the position (mark position information) of the alignment mark MKm (MK1 to MK4) on the substrate P by performing image analysis of a plurality of imaging signals. The alignment illumination light is light in a wavelength region that has little sensitivity to the photosensitive functional layer on the substrate P, for example, light having a wavelength of about 500 to 800 nm.

  A plurality of alignment marks MK1 to MK4 are provided around each exposure region W. A plurality of alignment marks MK1 and MK4 are formed on both sides of the exposure region W in the width direction of the substrate P along the longitudinal direction of the substrate P at a constant interval Dh. The alignment mark MK1 is formed on the −Y direction side in the width direction of the substrate P, and the alignment mark MK4 is formed on the + Y direction side in the width direction of the substrate P. Such alignment marks MK1 and MK4 are located at the same position in the longitudinal direction (X direction) of the substrate P when the substrate P is not deformed due to a large tension or a thermal process. Be placed. Further, the alignment marks MK2 and MK3 are between the alignment mark MK1 and the alignment mark MK4, and extend along the width direction (short direction) of the substrate P in the margin part between the + X direction side and the −X direction side of the exposure region W. Is formed. The alignment marks MK2 and MK3 are formed between the exposure area W and the exposure area W. The alignment mark MK2 is formed on the −Y direction side in the width direction of the substrate P, and the alignment mark MK3 is formed on the + Y direction side of the substrate P.

  Further, the spacing in the Y direction between the alignment mark MK1 and the alignment mark MK2 in the blank portion arranged at the −Y direction end of the substrate P, the spacing in the Y direction between the alignment mark MK2 in the blank portion and the alignment mark MK3, and The interval in the Y direction between the alignment mark MK4 arranged at the end on the + Y direction side of the substrate P and the alignment mark MK3 in the blank portion is set to the same distance. These alignment marks MKm (MK1 to MK4) may be formed together when the first pattern layer is formed. For example, when the pattern of the first layer is exposed, the alignment mark pattern may be exposed around the exposure area W where the pattern is exposed. The alignment mark MKm may be formed in the exposure area W. For example, it may be formed in the exposure area W along the outline of the exposure area W. Further, a pattern portion at a specific position or a specific shape portion in the pattern of the electronic device formed in the exposure region W may be used as the alignment mark MKm.

  As shown in FIG. 3, the alignment microscopes AM11 and AM21 are arranged so as to image the alignment mark MK1 existing in the observation areas (detection areas) Vw11 and Vw21 by the objective lens. Similarly, the alignment microscopes AM12 to AM14 and AM22 to AM24 are arranged so as to image the alignment marks MK2 to MK4 existing in the observation regions Vw12 to Vw14 and Vw22 to Vw24 by the objective lens. Therefore, the plurality of alignment microscopes AM11 to AM14 and AM21 to AM24 correspond to the positions of the plurality of alignment marks MK1 to MK4, and the substrates P in the order of AM11 to AM14 and AM21 to AM24 from the −Y direction side of the substrate P. It is provided along the width direction. In FIG. 2, the observation region Vw2m (Vw21 to Vw24) of the alignment microscope AM2m (AM21 to AM24) is not shown.

  In the plurality of alignment microscopes AM1m (AM11 to AM14), the distance in the longitudinal direction between the exposure position (drawing lines SL1 to SL6) and the observation region Vw1m (Vw11 to Vw14) in the X direction is the X direction of the exposure region W. It is provided to be shorter than the length. Similarly, in the plurality of alignment microscopes AM2m (AM21 to AM24), the distance in the longitudinal direction between the exposure position (drawing lines SL1 to SL6) and the observation region Vw2m (Vw21 to Vw24) is X in the exposure region W with respect to the X direction. It is provided to be shorter than the length in the direction. The number of alignment microscopes AM1m and AM2m provided in the Y direction can be changed according to the arrangement and number of alignment marks MKm formed in the width direction of the substrate P. The sizes of the observation regions Vw1m (Vw11 to Vw14) and Vw2m (Vw21 to Vw24) on the irradiated surface of the substrate P are set according to the sizes of the alignment marks MK1 to MK4 and the alignment accuracy (position measurement accuracy). However, it is about 100 to 500 μm square.

  As shown in FIG. 2, scale portions SDa and SDb having scales formed in an annular shape over the entire circumferential direction of the outer peripheral surface of the rotary drum DR are provided at both ends of the rotary drum DR. The scale portions SDa and SDb are diffraction gratings in which concave or convex lattice lines (scales) are engraved at a constant pitch (for example, 20 μm) in the circumferential direction of the outer peripheral surface of the rotating drum DR. Configured as The scale portions SDa and SDb rotate integrally with the rotary drum DR around the central axis AXo. A plurality of encoder heads (hereinafter also simply referred to as encoders) ENja and ENjb (j = 1, 2, 3, 4) as scale reading heads for reading the scale portions SDa and SDb are opposed to the scale portions SDa and SDb. (See FIGS. 1 and 2). In FIG. 2, the encoders EN4a and EN4b are not shown.

  The encoders ENja and ENjb optically detect the rotational angle position of the rotary drum DR. Four encoders ENja (EN1a, EN2a, EN3a, EN4a) are provided to face the scale portion SDa provided at the end portion on the −Y direction side of the rotary drum DR. Similarly, four encoders ENjb (EN1b, EN2b, EN3b, EN4b) are provided so as to face the scale part SDb provided at the end on the + Y direction side of the rotary drum DR.

  The encoders EN1a and EN1b are provided on the upstream side (−X direction side) in the transport direction of the substrate P with respect to the center plane Poc, and are disposed on the installation direction line Lx1 (see FIGS. 1 and 2). . The installation azimuth line Lx1 is a line connecting the projection positions (reading positions) of the measurement light beams on the scale portions SDa and SDb of the encoders EN1a and EN1b and the central axis AXo on the XZ plane. Further, the installation orientation line Lx1 is a line connecting the observation region Vw1m (Vw11 to Vw14) of each alignment microscope AM1m (AM11 to AM14) and the central axis AXo on the XZ plane. That is, the plurality of alignment microscopes AM1m (AM11 to AM14) are also arranged on the installation direction line Lx1.

  The encoders EN2a and EN2b are provided on the upstream side (−X direction side) in the transport direction of the substrate P with respect to the center plane Poc, and downstream in the transport direction of the substrate P (+ X direction) from the encoders EN1a and EN1b. Side). The encoders EN2a and EN2b are disposed on the installation direction line Lx2 (see FIGS. 1 and 2). The installation azimuth line Lx2 is a line connecting the projection positions (reading positions) of the light beams for measurement of the encoders EN2a and EN2b onto the scale portions SDa and SDb and the central axis AXo on the XZ plane. The installation azimuth line Lx2 overlaps with the irradiation center axes Le1, Le3, Le5 at the same angular position in the XZ plane.

  The encoders EN3a and EN3b are provided on the downstream side (+ X direction side) in the transport direction of the substrate P with respect to the center plane Poc, and are disposed on the installation direction line Lx3 (see FIGS. 1 and 2). The installation azimuth line Lx3 is a line connecting the projection positions (reading positions) of the measurement light beams on the scale portions SDa and SDb of the encoders EN3a and EN3b and the central axis AXo on the XZ plane. This installation orientation line Lx3 overlaps with the irradiation center axes Le2, Le4, and Le6 at the same angular position in the XZ plane. Therefore, the installation azimuth line Lx2 and the installation azimuth line Lx3 are set so that the angle is ± θ1 with respect to the center plane Poc in the XZ plane (see FIG. 1).

  The encoders EN4a and EN4b are provided on the downstream side (+ X direction side) in the transport direction of the substrate P from the encoders EN3a and EN3b, and are disposed on the installation direction line Lx4 (see FIG. 1). The installation azimuth line Lx4 is a line connecting the projection positions (reading positions) of the measurement light beams on the scale portions SDa and SDb of the encoders EN4a and EN4b and the central axis AXo on the XZ plane. Further, the installation orientation line Lx4 is a line connecting the observation region Vw2m (Vw21 to Vw24) of each alignment microscope AM2m (AM21 to AM24) and the central axis AXo on the XZ plane. That is, the plurality of alignment microscopes AM2m (AM21 to AM24) are also arranged on the installation direction line Lx4. The installation azimuth line Lx1 and the installation azimuth line Lx4 are set so that the angle is ± θ2 with respect to the center plane Poc in the XZ plane.

  Each encoder ENja (EN1a to EN4a), ENjb (EN1b to EN4b) projects a measurement light beam toward the scale portions SDa and SDb, and a detection signal (two-phase) obtained by photoelectrically detecting the reflected light beam (diffracted light). Signal) to the control device 16. In the controller 16, the detection signal (two-phase signal) for each encoder is interpolated, and the amount of movement of the grids of the scale portions SDa and SDb is digitally counted. Alternatively, a plurality of counter circuits are provided for measuring the movement amount of the substrate P with sub-micron resolution (resolution that is a fraction of the pixel size on the substrate P set in the design). From the change in the angle of the rotary drum DR, the transport speed Vt of the substrate P can also be measured. Based on the count value (digital count value) of the counter circuit corresponding to each of the encoders ENja (EN1a to EN4a) and ENjb (EN1b to EN4b), the position of the alignment mark MKm (MK1 to MK4), the exposure area on the substrate P The positional relationship in the sub-scanning direction between W and each drawing line SLn can be specified. In addition, based on the count value (digital count value) of the counter circuit, the address position (access address) in the sub-scanning direction of the memory unit for storing the drawing data (for example, bitmap data) of the pattern to be drawn on the substrate P Is also specified. As shown in FIG. 2, a Z-phase mark ZZ representing the origin position in the circumferential direction is formed at one place in the circumferential direction of the scale part SDa (SDb), and encoders ENja (EN1a to EN4a), ENjb (EN1b to Each of the EN4b), when detecting the Z-phase mark ZZ, resets the count value of the corresponding counter circuit to zero (or a constant value) instantaneously, and then sets the moving amount of the lattice of the scale portion SDa (SDb). Continue to measure.

  Next, the optical configuration of the scanning units Un (U1 to U6) will be described with reference to FIG. Since each scanning unit Un (U1 to U6) has the same configuration, only the scanning unit U1 will be described as a representative, and the description of the other scanning units Un will be omitted. In FIG. 4, the direction parallel to the irradiation center axis Len (Le1) is the Zt direction, and the substrate P is on a plane orthogonal to the Zt direction, and the substrate P passes from the processing apparatus PR1 to the processing apparatus PR2 via the exposure apparatus EX. The direction toward the Xt direction is defined as the Yt direction, and the direction perpendicular to the Xt direction on the plane orthogonal to the Zt direction is defined as the Yt direction. That is, the three-dimensional coordinates Xt, Yt, and Zt in FIG. 4 are the same as the three-dimensional coordinates X, Y, and Z in FIG. 1, and the Z-axis direction is parallel to the irradiation center axis Len (Le1). Thus, the three-dimensional coordinates rotated are as follows.

  As shown in FIG. 4, in the scanning unit U1, along the traveling direction of the beam LB1 from the incident position of the beam LB1 to the irradiated surface (substrate P), a reflection mirror M10, a beam expander BE, a reflection mirror M11, Polarization beam splitter BS1, reflection mirror M12, shift optical member (parallel plate) SR, deflection adjustment optical member (prism) DP, field aperture FA, reflection mirror M13, λ / 4 wavelength plate QW, cylindrical lens CYA, reflection mirror M14, A polygon mirror PM, an fθ lens FT, a reflection mirror M15, and a cylindrical lens CYb are provided. Further, in the scanning unit U1, an origin sensor (origin detector, detection sensor) OP1 for detecting the timing when the drawing of the scanning unit U1 can be started, and a polarization beam splitter BS1 for reflecting light from the irradiated surface (substrate P). And an optical lens system G10 and a photodetector DT for detection.

  The beam LB1 incident on the scanning unit U1 travels in the −Zt direction, and is incident on the reflection mirror M10 inclined by 45 ° with respect to the XtYt plane. The axis of the beam LB1 incident on the scanning unit U1 is incident on the reflection mirror M10 so as to be coaxial with the irradiation center axis Le1. The reflection mirror M10 moves the incident beam LB1 in the −Xt direction toward the reflection mirror M11 that is separated in the −Xt direction from the reflection mirror M10 along the optical axis AXa of the beam expander BE set parallel to the Xt axis. reflect. Therefore, the optical axis AXa is orthogonal to the irradiation center axis Le1 in a plane parallel to the XtZt plane. The beam expander BE includes a condensing lens Be1 and a collimating lens Be2 that collimates the beam LB1 diverged after being converged by the condensing lens Be1, and expands the diameter of the beam LB1.

  The reflection mirror M11 is disposed with an inclination of 45 ° with respect to the YtZt plane, and reflects the incident beam LB1 (optical axis AXa) toward the polarization beam splitter BS1 in the −Yt direction. The polarization separation surface of the polarization beam splitter BS1 disposed away from the reflection mirror M11 in the -Yt direction is disposed at an angle of 45 ° with respect to the YtZt plane, reflects the P-polarized beam, and is orthogonal to the P-polarized light. It transmits a linearly polarized (S-polarized) beam polarized in the direction. Since the beam LB1 incident on the scanning unit U1 is a P-polarized beam here, the polarization beam splitter BS1 reflects the beam LB1 from the reflection mirror M11 in the -Xt direction and guides it to the reflection mirror M12 side.

  The reflection mirror M12 is disposed with an inclination of 45 ° with respect to the XtYt plane, and reflects the incident beam LB1 in the −Zt direction toward the reflection mirror M13 that is separated from the reflection mirror M12 in the −Zt direction. The beam LB1 reflected by the reflection mirror M12 is shifted along the optical axis AXc parallel to the Zt axis by the shift optical member SR composed of two quartz parallel plates Sr1 and Sr2, and two wedge-shaped prisms Dp1 and Dp2. Is incident on the reflecting mirror M13 after passing through the deflection adjusting optical member DP and the field aperture (field stop) FA. The shift optical member SR tilts each of the parallel plates Sr1 and Sr2 so that the center position in the cross section of the beam LB1 is two-dimensionally within a plane (XtYt plane) orthogonal to the traveling direction (optical axis AXc) of the beam LB1. To adjust. The deflection adjusting optical member DP rotates each of the prisms Dp1 and Dp2 around the optical axis AXc so that the axis of the beam LB1 is parallel to the optical axis AXc, or the beam LB1 reaches the irradiated surface of the substrate P. These axes can be parallel to the irradiation center axis Le1.

  The reflection mirror M13 is disposed at an angle of 45 ° with respect to the XtYt plane, and reflects the incident beam LB1 toward the reflection mirror M14 in the + Xt direction. The beam LB1 reflected by the reflection mirror M13 enters the reflection mirror M14 via the λ / 4 wavelength plate QW and the cylindrical lens CYa. The reflection mirror M14 reflects the incident beam LB1 toward the polygon mirror (rotating polygonal mirror, scanning deflection member) PM. The polygon mirror PM reflects the incident beam LB1 toward the + Xt direction toward the fθ lens FT having the optical axis AXf parallel to the Xt axis. The polygon mirror PM deflects (reflects) the incident beam LB1 in a one-dimensional manner in a plane parallel to the XtYt 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 PM has a rotation axis AXp extending in the Zt-axis direction and a plurality of reflection surfaces RP formed around the rotation axis AXp (in this embodiment, the number Np of reflection surfaces RP is eight). ). By rotating the 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 RP can be continuously changed. As a result, the reflection direction of the beam LB1 is deflected by the single reflection surface RP, and the spot light SP of the beam LB1 irradiated on the irradiated surface of the substrate P is changed in the main scanning direction (width direction of the substrate P, Yt direction). Can be scanned along.

  That is, the spot light SP of the beam LB1 can be scanned once along the main scanning direction by one reflecting surface RP of the polygon mirror PM. For this reason, the number of drawing lines SL1 in which the spot light SP is scanned on the irradiated surface of the substrate P by one rotation of the polygon mirror PM is eight, which is the same as the number of the reflecting surfaces RP. The polygon mirror PM is rotated at a constant speed by a rotation drive source (for example, a motor, a reduction mechanism, etc.) RM under the control of the control device 16. As described above, the effective length (for example, 30 mm) of the drawing line SL1 is equal to or shorter than the maximum scanning length (for example, 31 mm) that allows the spot light SP to be scanned by the polygon mirror PM. In the initial setting (design), the center point of the drawing line SL1 (the point through which the irradiation center axis Le1 passes) is set at the center of the maximum scanning length.

  The cylindrical lens CYa converges the incident beam LB1 on the reflection surface RP of the polygon mirror PM in the non-scanning direction (Zt direction) orthogonal to the main scanning direction (rotation direction) by the polygon mirror PM. That is, the cylindrical lens CYa converges the beam LB1 into a slit shape (ellipse shape) extending in a direction parallel to the XtYt plane on the reflection surface RP. When the reflecting surface RP is inclined with respect to the Zt direction by a cylindrical lens CYa whose generating line is parallel to the Yt direction and a cylindrical lens CYb described later (inclination of the reflecting surface RP with respect to the normal of the XtYt plane). Even if it exists, the influence can be suppressed. For example, it is possible to prevent the irradiation position of the beam LB1 (drawing line SL1) irradiated on the irradiated surface of the substrate P from shifting in the Xt direction due to a slight tilt error for each reflecting surface RP of the polygon mirror PM. it can.

  The fθ lens FT having the optical axis AXf extending in the Xt axis direction is a telecentric scan lens that projects the beam LB1 reflected by the polygon mirror PM onto the reflection mirror M15 so as to be parallel to the optical axis AXf on the XtYt plane. It is. The incident angle θ of the beam LB1 to the fθ lens FT changes according to the rotation angle (θ / 2) of the polygon mirror PM. The fθ lens FT projects the beam LB1 to the image height position on the irradiated surface of the substrate P in proportion to the incident angle θ through the reflection mirror M15 and the cylindrical lens CYb. When the focal length is fo and the image height position is y, the fθ lens FT is designed so as to satisfy the relationship y = fo × θ (distortion aberration). Therefore, the fθ lens FT enables the beam LB1 to be scanned accurately at a constant speed in the Yt direction (Y direction). When the incident angle θ to the fθ lens FT is 0 degree, the beam LB1 incident on the fθ lens FT travels along the optical axis AXf.

  The reflection mirror M15 reflects the beam LB1 from the fθ lens FT in the −Zt direction toward the substrate P via the cylindrical lens CYb. By the fθ lens FT and the cylindrical lens CYb in which the generatrix is parallel to the Yt direction, the beam LB1 projected on the substrate P is a minute spot light having a diameter of about several μm (for example, 3 μm) on the irradiated surface of the substrate P. Converged to SP. The spot light SP projected on the irradiated surface of the substrate P is one-dimensionally scanned by the polygon mirror PM along the drawing line SL1 extending in the Yt direction. The optical axis AXf of the fθ lens FT and the irradiation center axis Le1 are on the same plane, and the plane is parallel to the XtZt plane. Therefore, the beam LB1 traveling on the optical axis AXf is reflected in the −Zt direction by the reflection mirror M15, and is projected on the substrate P coaxially with the irradiation center axis Le1. In the first embodiment, at least the fθ lens FT functions as a projection optical system that projects the beam LB1 deflected by the polygon mirror PM onto the irradiated surface of the substrate P. At least the reflecting members (reflecting mirrors M11 to M15) and the polarizing beam splitter BS1 function as an optical path deflecting member that bends the optical path of the beam LB1 from the reflecting mirror M10 to the substrate P. By this optical path deflecting member, the incident axis of the beam LB1 incident on the reflecting mirror M10 and the irradiation center axis Le1 can be made substantially coaxial. With respect to the XtZt plane, the beam LB1 passing through the scanning unit U1 travels in the −Zt direction and is projected onto the substrate P after passing through the optical path bent in a crank shape.

  In this way, with the substrate P being transported in the sub-scanning direction, the spot light SP of the beam LBn (LB1-LB6) is primary in the main scanning direction (Y direction) by each scanning unit Un (U1-U6). By performing original scanning, the spot light SP can be relatively two-dimensionally scanned on the irradiated surface of the substrate P.

  As an example, the effective length (drawing length) of each of the drawing lines SL1 to SL6 is 30 mm, and the effective size φ is ½ each of the spot light SP with 3 μm, that is, 1.5 (= 3 When the spot light SP is irradiated onto the irradiated surface of the substrate P along the drawing lines SLn (SL1 to SL6) while being overlapped by × 1/2) μm, the pulsed spot light SP is 1.5 μm. Irradiated at intervals. Therefore, the number of spot lights SP irradiated in one scan is 20000 (= 30 [mm] /1.5 [μm]). Further, assuming that the feed speed (conveyance speed) Vt of the substrate P in the sub-scanning direction is 2.42 mm / sec and that the spot light SP is also scanned in the sub-scanning direction at intervals of 1.5 μm. The time difference (period) Tpx between the time when the first scan (drawing start) and the next time when the next scan is started is about 620 μsec (= 1.5 [μm] /2.42 [mm / sec]). . This time difference Tpx is a time required for the polygon mirror PM of the eight reflecting surfaces RP to rotate by one surface (45 degrees = 360 degrees / 8). In this case, since the time for one rotation of the polygon mirror PM needs to be set to be about 4.96 msec (= 8 × 620 [μsec]), the rotation speed Vp of the polygon mirror PM is about 201 per second. .613 revolutions (= 1 / 4.96 [msec]), that is, about 12096.8 rpm.

  On the other hand, the maximum incident angle (corresponding to the maximum scanning length of the spot light SP) at which the beam LB1 reflected by one reflecting surface RP of the polygon mirror PM effectively enters the fθ lens FT is the focal length and the maximum scanning length of the fθ lens FT It will be roughly decided by. As an example, when the reflecting surface RP is eight polygon mirrors PM, the ratio (scanning efficiency) of the rotation angle α that contributes to actual scanning out of the rotation angle 45 degrees for one reflection surface RP is α / 45 degrees. expressed. In the first embodiment, since the rotation angle α that contributes to actual scanning is in a range larger than 10 degrees and smaller than 15 degrees, the scanning efficiency is 1/3 (= 15 degrees / 45 degrees), and fθ. The maximum incident angle of the lens FT is 30 degrees (± 15 degrees with respect to the optical axis AXf). Therefore, the time Ts required to scan the spot light SP by the maximum scanning length (for example, 31 mm) of the drawing line SLn is Ts = Tpx × scanning efficiency. In the case of the above numerical example, the time Ts, About 206.666... Μsec (= 620 [μsec] / 3). Since the effective scanning length of the drawing lines SLn (SL1 to SL6) in the first embodiment is 30 mm, the scanning time Tsp of one scanning of the spot light SP along the drawing lines SLn is about 200 μsec ( = 206.666 (μsec) × 30 (mm) / 31 (mm)). Accordingly, since it is necessary to irradiate 20000 spot light SP (pulse light) during this time Tsp, the emission frequency (oscillation frequency) Fa of the beam LB from the light source device LS is Fa≈20,000 times / 200 μsec≈ 100 MHz.

  The origin sensor OP1 shown in FIG. 4 generates an origin signal SZ1 when the rotational position of the reflection surface RP of the polygon mirror PM reaches a predetermined position where the scanning of the spot light SP by the reflection surface RP can be started. In other words, the origin sensor OP1 generates the origin signal SZ1 when the angle of the reflection surface RP from which the spot light SP is scanned becomes a predetermined angular position. Since the polygon mirror PM has eight reflecting surfaces RP, the origin sensor OP1 outputs the origin signal SZ1 eight times during the period in which the polygon mirror PM rotates once. The origin signal SZ1 generated by the origin sensor OP1 is sent to the control device 16. After the origin sensor OP1 generates the origin signal SZ1, scanning of the spot light SP along the drawing line SL1 is started after the delay time Td1 has elapsed. That is, the origin signal SZ1 is information indicating the drawing start timing (scanning start timing) of the spot light SP by the scanning unit U1. The origin sensor OP1 includes a beam transmission system opa for emitting a laser beam Bga in a wavelength region that is non-photosensitive to the photosensitive functional layer of the substrate P to the reflection surface RP, and a laser beam Bga reflected by the reflection surface RP. And a beam receiving system opb that receives the reflected beam Bgb and generates an origin signal SZ1.

  The origin sensors OPn provided in the scanning units U2 to U6 are represented by OP2 to OP6, and origin signals SZn generated by the origin sensors OP2 to OP6 are represented by SZ2 to SZ6. Based on these origin signals SZn (SZ1 to SZ6), the control device 16 manages which scanning unit Un will scan the spot light SP from now on. Further, the delay time Tdn from when the origin signals SZ2 to SZ6 are generated to when the scanning units U2 to U6 start scanning the spot light SP along the drawing lines SL2 to SL6 may be represented by Td2 to Td6. In the present embodiment, using the origin signals SZ1 to SZ6, synchronous control for matching the rotational speed of the polygon mirror PM of each of the scanning units U1 to U6 to a predetermined value, and the rotational angular position (angular phase) of each polygon mirror PM. Is synchronized with the predetermined relationship.

  The photodetector DT shown in FIG. 4 is, for example, reflected light generated when a reference pattern formed on the surface of the rotating drum DR or a reference pattern formed at a specific position on the substrate P is scanned with the spot light SP. A photoelectric conversion element that photoelectrically converts the change of If the spot light SP of the beam LB1 is irradiated from the scanning unit U1 to the area where the reference pattern (or the reference pattern on the substrate P) of the rotary drum DR is formed, the reflected light is reflected from the fθ lens FT being a telecentric system. Are cylindrical lens CYb, reflection mirror M15, fθ lens FT, polygon mirror PM, reflection mirror M14, cylindrical lens CYa, λ / 4 wavelength plate QW, reflection mirror M13, field aperture FA, deflection adjustment optical member DP, shift optical member The light passes through SR and the reflection mirror M12 and returns to the polarization beam splitter BS1. The beam LB1 irradiated to the substrate P is converted from the P-polarized light to the circularly-polarized beam LB1 by the action of the λ / 4 wavelength plate QW, reflected by the surface of the rotating drum DR (or the surface of the substrate P), and polarized. The reflected light returning to the beam splitter BS1 is converted from circularly polarized light to S polarized light by the λ / 4 wavelength plate QW, passes through the polarized beam splitter BS1, and reaches the photodetector DT via the optical lens system G10. The scanning unit Un can be calibrated based on the position information of the reference pattern with respect to the drawing line SLn measured based on the detection signal from the photodetector DT.

  FIG. 5 is a diagram of the configuration in the beam distribution unit BDU viewed in the XY plane. The beam distribution unit BDU includes a plurality of drawing optical elements AOMn (AOM1 to AOM6), a plurality of beam splitters BSa to BSe, a plurality of reflection mirrors MR1 to MR5, and a plurality of reflection mirrors FM1 to FM6. Have. The drawing optical elements AOMn (AOM1 to AOM6) are arranged in each of the optical paths in which the beam LB from the light source device LS is distributed into six, and the first-order diffracted light that diffracts the incident beam in response to a high-frequency drive signal. , An acousto-optic modulator (AOM) that emits as beams LBn (LB1 to LB6). The diffraction direction of the first-order diffracted light (beams LB1 to LB6) in each of the drawing optical elements AOMn (AOM1 to AOM6) is the −Z direction in a plane parallel to the XZ plane, and each drawing optical element AOMn is in the on state ( The beam LBn (LB1 to LB6) emitted from each drawing optical element AOMn in the state where the first-order diffracted light is generated) is reflected on each of the reflecting mirrors FM1 to FM6 for incident light whose reflecting surfaces are inclined with respect to the XY plane. Is reflected in the −Z direction toward the corresponding scanning units U1 to U6 (reflection mirror M10).

  The beam LB from the light source device LS is divided into two by the beam splitter BSa, and the beam transmitted through the beam splitter BSa is reflected by the reflection mirrors MR1 and MR2, and then divided into two by the beam splitter BSb. The beam reflected by the beam splitter BSb enters the drawing optical element AOM5. The beam transmitted through the beam splitter BSb is divided into two by the beam splitter BSc, and the beam reflected by the beam splitter BSc is incident on the drawing optical element AOM3. The beam that has passed through the beam splitter BSc is reflected by the reflection mirror MR3 and enters the drawing optical element AOM1. Similarly, the beam reflected by the beam splitter BSa is reflected by the reflection mirror MR4 and then divided into two by the beam splitter BSd. The beam reflected by the beam splitter BSd enters the drawing optical element AOM6. The beam that has passed through the beam splitter BSd is divided into two by the beam splitter BSe, and the beam reflected by the beam splitter BSe is incident on the drawing optical element AOM4. The beam that has passed through the beam splitter BSe is reflected by the reflection mirror MR5 and enters the drawing optical element AOM2.

  As described above, the beam LB from the light source device LS is incident on each of the six drawing optical elements AOMn (AOM1 to AOM6) while being amplitude-divided (intensity-divided) by about 1/6. Each of the scanning units Un (U1 to U6) is turned on / off by applying a high-frequency drive signal to each of the drawing optical elements AOMn (AOM1 to AOM6) according to the bit data for each pixel of the drawing data. The intensity of the spot light SP scanned along the drawing line SLn is modulated. Thereby, a pattern corresponding to the drawing data (bitmap) is simultaneously drawn on the substrate P by each scanning unit Un (U1 to U6). The drawing data (pattern data) is provided for each scanning unit Un, and a pattern drawn by the scanning unit Un is divided by pixels having dimensions set according to the size φ of the spot light SP, and each of the plurality of pixels is divided. Is represented by 1-bit logical information (bit data, pixel data) corresponding to the pattern. That is, in the drawing data, the direction along the scanning direction (main scanning direction, Y direction) of the spot light SP is the row direction, and the direction along the transport direction (sub-scanning direction, X direction) of the substrate P is the column direction. Thus, it is bitmap data composed of logical information (pixel data) of a plurality of pixels that are two-dimensionally decomposed.

  The logical information of the pixels for one column of the drawing data corresponds to one drawing line SLn (SL1 to SL6). Therefore, the number of pixels for one column is determined according to the pixel size Pxy on the irradiated surface of the substrate P and the length of the drawing line SLn. The size Pxy of one pixel is set to be equal to or larger than the size φ of the spot light SP. For example, when the effective size φ of the spot light SP is 3 μm, the size Pxy of one pixel is It is set to about 3 μm square or more. The intensity of the spot light SP projected onto the substrate P along one drawing line SLn (SL1 to SL6) is modulated according to the logical information of the pixels for one column. The logical information (bit data) of the pixels for one column is referred to as a pixel data column DLn. That is, the drawing data is bitmap data in which pixel data columns DLn are arranged in the column direction. The pixel data string DLn of the drawing data of the scanning unit U1 is represented by DL1, and similarly, the pixel data string DLn of the drawing data of the scanning units U2 to U6 is represented by DL2 to DL6. When the bit data of the pixel is “1”, it means that the intensity of the spot light SP projected onto the substrate P becomes high, that is, the drawing optical element AOMn generates the first-order diffracted light. Further, “0” means that the intensity of the spot light SP projected onto the substrate P is low (for example, zero), that is, the drawing optical element AOMn does not generate the first-order diffracted light.

  FIG. 6 is a block diagram showing a main configuration of the control device 16 shown in FIG. 1. The control device 16 controls the drawing control unit 100 that controls the entire drawing operation and the origins of the scanning units U1 to U6. The origin signals SZ1 to SZ6 from the beam receiving system opb of the sensor OPn are input and captured by the polygon mirror driving unit 102 that controls the motor RM for rotating the polygon mirror PM and each of the plurality of alignment microscopes AM1m and AM2m. Based on the alignment unit 104 that analyzes the images of the alignment marks MK1 to MK4 to generate mark position information and detection signals (two-phase signals) from each of the plurality of encoders EN1a to EN4a and EN1b to EN4b Digitally counts the movement amount and movement position of the parts SDa and SDb in the circumferential direction, and also the scale part The encoder counter unit 106 which is reset to zero by the Z-phase mark ZZ for each rotation of Da and SDb (or the rotating drum DR), and the drawing data of the pattern to be drawn by each of the scanning units U1 to U6 are stored in bitmap format. The drawing data storage unit 108 and the drawing optical element AOM1 corresponding to each of the scanning units U1 to U6 according to the drawing data string (bit stream signal) for each of the drawing lines SL1 to SL6 read from the drawing data storage unit 108. AOM driving unit 110 that modulates .about.AOM6 and a drive control unit 112 that controls the rotational driving motor of the rotating drum DR. Furthermore, the drawing control unit 100 sends information TMg and CMg for correcting the drawing magnification to the light source device LS, and at the timing when each of the scanning units U1 to U6 scans the substrate P with the spot light SP, the light source device LS. Generates a drawing switch signal SHT for controlling to emit the beam LB by monitoring the generation state of the origin signals SZ1 to SZ6.

  In the present embodiment, the beam LB of the light source device LS is pulsed light having an oscillation frequency Fa (for example, 100 MHz). For this purpose, the light source device LS generates a clock signal LTC having the oscillation frequency Fa. One clock pulse of the clock signal LTC corresponds to one pulse emission of the beam LB. Furthermore, the light source device LS includes a local magnification correction unit that partially finely adjusts the period of the clock signal LTC at a specific pixel position while the spot light SP is scanned along the drawing line SLn. The clock signal LTC is also used for managing the rotational speed of the polygon mirror PM by the polygon mirror driving unit 102. Further, the light source device LS shifts the pixel data string DLn sent from the drawing data storage unit (data storage unit) 108 to the AOM drive unit 110 during one scan of the spot light SP for each bit data of one pixel. The pixel shift signal (pixel shift pulse) BSC is generated.

  FIG. 7 is a diagram showing a specific configuration of a light source device (pulse light source device, pulse laser device) LS. The light source device LS as a fiber laser device includes a pulsed light generation unit 20 and a control circuit 22. The pulse light generator 20 includes DFB semiconductor laser elements 30 and 32, a polarization beam splitter 34, an electro-optic element (intensity modulation section) 36 as a drawing optical modulator, a drive circuit 36a for the electro-optic element 36, and a polarization beam splitter. 38, an absorber 40, an excitation light source 42, a combiner 44, a fiber optical amplifier 46, wavelength conversion optical elements 48 and 50, and a plurality of lens elements GL. The control circuit 22 has a signal generator 22a that generates a clock signal LTC and a pixel shift pulse BSC.

  In response to the clock signal LTC, the DFB semiconductor laser element (first solid-state laser element) 30 has sharp or sharp pulsed seed light (pulse beam, beam) at an oscillation frequency Fa (for example, 100 MHz) which is a predetermined frequency. ) S1 is generated, and the DFB semiconductor laser element (second solid-state laser element) 32 responds to the clock signal LTC and has a slow (time broad) pulse at an oscillation frequency Fa (for example, 100 MHz) which is a predetermined frequency. A seed light (pulse beam, beam) S2 is generated. The seed light S1 generated by the DFB semiconductor laser element 30 and the seed light S2 generated by the DFB semiconductor laser element 32 are synchronized in emission timing. The seed lights S1 and S2 both have substantially the same energy per pulse, but have different polarization states, and the peak intensity of the seed light S1 is stronger. The seed light S1 and the seed light S2 are linearly polarized light, and their polarization directions are orthogonal to each other. In the first embodiment, the polarization state of the seed light S1 generated by the DFB semiconductor laser element 30 will be described as S-polarized light, and the polarization state of the seed light S2 generated by the DFB semiconductor laser element 32 will be described as P-polarized light. The seed lights S1 and S2 are light in the infrared wavelength region.

  The control circuit 22 controls the DFB semiconductor laser elements 30 and 32 so that the seed lights S1 and S2 emit light in response to the clock pulse of the clock signal LTC sent from the signal generator 22a. As a result, the DFB semiconductor laser elements 30 and 32 emit the seed lights S1 and S2 simultaneously at a predetermined frequency (oscillation frequency) Fa in response to each clock pulse (oscillation frequency Fa) of the clock signal LTC. The control circuit 22 is controlled by the drawing control unit 100 in the control device 16. The clock pulse period (= 1 / Fa) of the clock signal LTC is referred to as a reference period Ta. The seed lights S 1 and S 2 generated by the DFB semiconductor laser elements 30 and 32 are guided to the polarization beam splitter 34.

  As will be described in detail later, the clock signal LTC serving as the reference clock signal designates an address in the row direction (main scanning direction) in the memory circuit that stores bitmap-like drawing pattern data in the drawing data storage unit 108. This is the base of the pixel shift pulse BSC supplied to the address counter (register). Further, the signal generator 22a includes the overall magnification correction information TMg for correcting the overall magnification of the drawing line SLn on the irradiated surface of the substrate P, and the local magnification correction information for correcting the local magnification of the drawing line SLn. CMg is sent from the drawing control unit 100 in the control device 16. Thereby, the length (scanning length) of the drawing line SLn on the irradiated surface of the substrate P can be finely adjusted from the ppm order to the% order. The expansion / contraction (fine adjustment of the scanning length) of the drawing line SLn can be performed within the range of the maximum scanning length (for example, 31 mm) of the drawing line SLn. The overall magnification correction in the first embodiment is projected along the main scanning direction with the number of spot lights SP corresponding to one pixel (1 bit) on the drawing data being constant. By uniformly finely adjusting the projection interval of the spot light SP (that is, the cycle of the clock signal LTC), the magnification in the scanning direction of the entire drawing line SLn is uniformly corrected. The local magnification correction in the first embodiment is a spot projected along the main scanning direction only at some discrete correction points (pixel positions) set on one drawing line. By temporarily increasing or decreasing the projection interval of the light SP (that is, the cycle of the clock signal LTC), the size of the pixel on the substrate corresponding to the correction point is slightly expanded or contracted in the main scanning direction.

  The polarization beam splitter 34 transmits S-polarized light and reflects P-polarized light. The polarization beam splitter 34 includes seed light S1 generated by the DFB semiconductor laser element 30 and seed light S2 generated by the DFB semiconductor laser element 32. Is guided to the electro-optic element 36. That is, the polarization beam splitter 34 guides the seed light S 1 to the electro-optic element 36 by transmitting the S-polarized seed light S 1 generated by the DFB semiconductor laser element 30. The polarization beam splitter 34 reflects the P-polarized seed light S2 generated by the DFB semiconductor laser element 32 to guide the seed light S2 to the electro-optic element 36. The DFB semiconductor laser elements 30 and 32 and the polarization beam splitter 34 constitute a pulse light source unit 35 that generates seed lights S1 and S2.

  The electro-optic element (intensity modulation section) 36 is transmissive to the seed lights S1 and S2, and for example, an electro-optic modulator (EOM) is used. The seed lights S1 and S2 from each of the DFB semiconductor laser element 30 and the DFB semiconductor laser element 32 have a long wavelength range of 800 nm or more. Therefore, the electro-optic element 36 having a polarization state switching response of about GHz is used. Can do. In response to the high / low state of the drawing switch signal SHT, the electro-optical element 36 switches the polarization states of the seed lights S1 and S2 by the drive circuit 36a. The drawing switch signal SHT is in a high state immediately before any of the scanning units U1 to U6 starts drawing, or at a time before the drawing start by a fixed time, and all of the scanning units U1 to U6 perform drawing. If not, it goes low. The drawing switch signal SHT is sent from the drawing control unit 100 that monitors the generation state of the origin signals SZ1 to SZ6 in FIG.

  When the drawing switch signal SHT input to the drive circuit 36a is in a low (“0”) state, the electro-optic element 36 directly guides it to the polarization beam splitter 38 without changing the polarization state of the seed lights S1 and S2. Conversely, when the drawing switch signal SHT input to the drive circuit 36a is in a high (“1”) state, the electro-optic element 36 changes the polarization state of the incident seed light S1 and S2, that is, changes the polarization direction. The beam is changed by 90 degrees and guided to the polarization beam splitter 38. The drive circuit 36a drives the electro-optical element 36 in this way, so that the electro-optical element 36 converts the S-polarized seed light S1 into the P-polarized seed light when the drawing switch signal SHT is in the high state (“1”). The light is converted into light S1, and the P-polarized seed light S2 is converted into S-polarized seed light S2.

  The polarization beam splitter 38 transmits P-polarized light and guides it to the combiner 44 through the lens element GL, and reflects S-polarized light to the absorber 40. The light (seed light) that passes through the polarization beam splitter 38 is represented by a beam Lse. The oscillation frequency of this pulsed beam Lse is Fa. The excitation light source 42 generates excitation light, and the excitation light is guided to the combiner 44 through the optical fiber 42a. The combiner 44 combines the beam Lse emitted from the polarization beam splitter 38 and the excitation light, and outputs the combined light to the fiber optical amplifier 46. The fiber optical amplifier 46 is doped with a laser medium that is pumped by pumping light. Therefore, in the fiber optical amplifier 46 that transmits the synthesized beam Lse and the pumping light, the laser medium is pumped by the pumping light, so that the beam Lse as the seed light is amplified. As the laser medium doped in the fiber optical amplifier 46, rare earth elements such as erbium (Er), ytterbium (Yb), thulium (Tm) are used. The amplified beam Lse is emitted from the exit end 46 a of the fiber optical amplifier 46 with a predetermined divergence angle, converged or collimated by the lens element GL, and enters the wavelength conversion optical element 48.

  The wavelength conversion optical element (first wavelength conversion optical element) 48 generates an incident beam Lse (wavelength λ) from the second harmonic generation (SHG) by a second harmonic generation (SHG). Convert to harmonics. As the wavelength conversion optical element 48, a PPLN (Periodically Poled LiNbO3) crystal which is a quasi phase matching (QPM) crystal is preferably used. It is also possible to use a PPLT (Periodically Poled LiTaO3) crystal or the like.

  The wavelength conversion optical element (second wavelength conversion optical element) 50 includes the second harmonic (wavelength λ / 2) converted by the wavelength conversion optical element 48 and the seed light remaining without being converted by the wavelength conversion optical element 48. A third frequency with a wavelength of 1/3 of λ is generated by sum frequency generation (SFG) with (wavelength λ). The third harmonic becomes ultraviolet light (beam LB) having a peak wavelength in a wavelength band of 370 mm or less (for example, 355 nm).

  When the drawing switch signal SHT applied to the drive circuit 36a is low (“0”), the electro-optic element (intensity modulation unit) 36 directly changes the polarization state of the incident seed lights S1 and S2 without changing the polarization state. Lead to. Therefore, the beam Lse that passes through the polarization beam splitter 38 becomes the seed light S2. In this case, the beam Lse has a low peak intensity of the pulse and has a broad and dull characteristic. Since the fiber optical amplifier 46 has low amplification efficiency for the seed light S2 having such a low peak intensity, the beam LB emitted from the light source device LS becomes light that is not amplified to the energy required for exposure. Therefore, from the viewpoint of exposure, the light source device LS has substantially the same result as not emitting the beam LB. That is, the intensity of the spot light SP applied to the substrate P is at a very low level. However, even during a period when the pattern is not exposed (non-drawing period), the ultraviolet beam LB derived from the seed light S2 is irradiated with a slight intensity. Therefore, when the drawing lines SL1 to SL6 remain in the same position on the substrate P for a long time (for example, when the substrate P is stopped due to a trouble in the transport system, etc.), the beam LB of the light source device LS. A movable shutter may be provided on the exit window (not shown) to close the exit window.

  On the other hand, when the drawing switch signal SHT applied to the drive circuit 36 a is high (“1”), the electro-optic element (intensity modulation unit) 36 changes the polarization state of the incident seed light S 1 and S 2 to change the polarization beam splitter 38. Lead to. Therefore, the beam Lse that passes through the polarization beam splitter 38 is generated from the seed light S 1 from the DFB semiconductor laser element 30. Since the seed light S1 from the DFB semiconductor laser element 30 has a strong peak intensity, it is efficiently amplified by the fiber optical amplifier 46, and the P-polarized beam LB output from the light source device LS is energy required for exposure of the substrate P. have. That is, the intensity of the spot light SP applied to the substrate P is at a high level. As described above, since the electro-optic element 36 responding to the drawing switch signal SHT is provided in the light source device LS, scanning is performed only during a period during which the drawing operation is performed by scanning the spot light SP while the polygon mirror PM is rotating. It is possible to cause the units U1 to U6 to transmit the beams LB (LB1 to LB6).

  In the configuration of FIG. 7, the DFB semiconductor laser element 32 and the polarization beam splitter 34 are omitted, and only the seed light S1 from the DFB semiconductor laser element 30 is switched by switching the polarization state of the electro-optic element 36, and the fiber optical amplifier 46. It is also conceivable to guide the light in burst waves. However, when this configuration is adopted, the incident periodicity (frequency Fa) of the seed light S1 to the fiber optical amplifier 46 is to be drawn, and the scanning cycle of the spot light SP along the drawing line SLn (each surface of the polygon mirror PM). In accordance with the reflection period of the beam LBn). That is, after the seed light S1 from the DFB semiconductor laser element 30 does not enter the fiber optical amplifier 46, when the seed light S1 suddenly enters the fiber optical amplifier 46, the seed light S1 immediately after the incident is more than usual. However, there is a problem that a beam having a greater intensity than specified is generated from the fiber optical amplifier 46. Therefore, in the present embodiment, as a preferable mode, the seed light S2 from the DFB semiconductor laser element 32 (time-broadly pulsed light with a reduced peak intensity) is a period in which the seed light S1 is not incident on the fiber optical amplifier 46. Is incident on the fiber optical amplifier 46 to solve such a problem.

  FIG. 8 is a diagram for explaining the timing of reading the drawing data (pixel data string DLn) according to the movement position (movement amount) of the substrate P by the drawing control unit 100 and the drawing data storage unit 108 shown in FIG. It is. Here, the drawing operation by the scanning unit U1 will be described as a representative. When the drawing magnification correction in the sub-scanning direction (X-scan direction) is not performed (magnification = 1.0), the encoder counter unit (digital counter) 106 counts by the encoder EN2a (or EN2b) corresponding to the scanning unit U1. The counted value corresponds to the rotation position of the rotary drum DR, that is, the movement amount (or movement position) of the substrate P, and is set as CX2. In FIG. 8, the movement amount CX <b> 2 is schematically represented by an arrangement of up / down pulses supplied to a corresponding counter circuit in the encoder counter unit 106. Here, the measurement resolution of the movement amount (movement position) CX2 is set to be smaller than the effective diameter size φ of the spot light SP. In the present embodiment, a drawing data storage unit is used as bit map data in which pixel data is divided into a matrix in the main scanning direction (Y scan direction) and the sub scanning direction (X scan direction). (Data storage unit) 108. The encoder counter unit 106, the scale units SDa and SDb, and the encoders ENja and ENjb constitute a measurement mechanism.

  It is assumed that one pixel on the drawing data is set to a 3 μm square on the substrate P, for example, similar to the size φ of the spot light SP. Further, since the spot light SP is projected onto the substrate P by overlapping each half of the size φ of the spot light SP with respect to the main scanning direction (Y scan direction) and the sub scanning direction (X scan direction). Two spot lights SP correspond to one pixel along the main scanning direction and the sub-scanning direction. Therefore, when the resolution of the movement amount CX2 of the substrate P counted by the encoder counter unit 106 is 1 / k of the pixel dimension (k is preferably 2 or more) and 0.3 μm per count (1 / k of 1k) In the case where k is 10, the drawing control unit 100 (or the drawing data storage unit 108), for every 10 counts of the movement amount CX2, addresses the drawing data stored in the memory of the drawing data storage unit 108 in the X scan direction. A signal XA2 for incrementing (X address value) one by one is generated. The drawing data storage unit 108 accesses the pixel data string DL1 for one column arranged in the Y scan direction in accordance with the signal XA2. Further, the drawing data storage unit 108 responds to the pixel shift pulse BSC obtained by dividing the clock signal LTC by 1/2, and the address (Y address value) in the Y scan direction of the accessed pixel data string DL1. The bit data (“0” or “1”) of the corresponding pixel is designated and output to the AOM driver 110 serially. As shown in FIG. 8, the cycle of the pixel shift pulse BSC is set to twice the cycle of the clock signal LTC, and the oscillation frequency Fa of the clock signal LTC and the rotation speed Vp of the polygon mirror PM are synchronized with each other along the drawing line SL1. The spot light SP scanned in this manner can be overlapped by ½ of the size φ. In the spot light SP shown in FIG. 8, the solid line is the spot light SP that reaches the substrate P by pulse light emission, and the broken line represents the pulse light emission (spot light SP) that has not been irradiated to the substrate P. Here, the X address This represents a case where a pixel data string DL1 (00011...) Having a value of 1 is drawn.

  In the above example, the ratio k between the resolution (movement amount for one count) of the movement amount CX2 of the substrate P counted by the encoder counter unit 106 and the pixel dimension Pxy is an integer (for simplicity of explanation). 10). However, the ratio k between the measurement resolution (the amount of movement per count) and the pixel dimension Pxy may not be an integer depending on the pitch of the scale portions SDa and SDb (diffraction grating) and the configuration of the encoder heads ENja and ENjb. is there. For example, when the actual measurement resolution of the encoder system is 0.312 μm / count and the designed pixel size Pxy is 3 μm square, the ratio k is about 9.615 (= 3/0). 312). In this case, assuming that 10 counts is the designed pixel size Pxy as the movement amount CX2 described with reference to FIGS. 9A to 11, the actual movement amount of the substrate P is 3.12 μm, which is about 4% per pixel ( = 0.12 / 3). Therefore, if pattern drawing is continued in this state in the sub-scanning direction, the pattern drawn in the exposure area W is enlarged by 4% overall in the sub-scanning direction without correcting the drawing magnification in the sub-scanning direction. Will be. This is a cumulative error less than LSB (least significant bit) that occurs during digital counting.

  Therefore, one countermeasure is that the count value of the movement amount CX2 of the substrate P counted by the encoder counter unit 106 is an error rate per pixel (actual 1 count with respect to the movement amount of 1 count assumed in the design). The cumulative error can be eliminated by performing a rounding operation for one count each time it increases by a number corresponding to the reciprocal of the ratio of the movement amount of minutes). For example, in the above example, when the error rate per pixel is + 4% (0.04), the count value of the movement amount CX2 of the substrate P counted by the encoder counter unit 106 is the reciprocal of the error rate. It is only necessary to provide an address counter that increments such that every time 25 (= 1 / 0.04) is counted, the next one count is not counted or the 25th count is not counted. As another countermeasure, there is a method of setting the designed pixel dimension Pxy in accordance with the actual movement amount (for example, 0.312 μm) for one count counted by the encoder counter unit 106. In this method, assuming that the pixel size Pxy of drawing data prepared in advance when using the exposure apparatus (pattern drawing apparatus) EX of the present embodiment is, for example, 3.12 μm square, CAD data of a pattern is converted into bitmap data. Can be converted to.

  Now, as shown in FIG. 8, the drawing control unit 100 has a measured movement amount (movement position) CX2 based on the count value of the encoder counter unit 106 so that the drawing line SL1 and the tip of the exposure area W coincide. When it coincides with the drawing start position Wst in the sub-scanning direction, the generation of the signal XA2 is started and the X address value is sequentially incremented. The drawing control unit 100 preferably generates the X address value by recounting the movement amount CX2 from zero with the drawing start position Wst as the zero point (start point). Further, as the substrate P moves in the sub-scanning direction, the scanning of the spot light SP along the drawing line SL1 is repeated at a pitch ΔXP in the sub-scanning direction. In the standard exposure mode, the pitch ΔXP is set to be about ½ of the effective size φ of the spot light SP on the substrate P. That is, the X-scan direction of one pixel is controlled so as to be drawn with two spot lights SP. However, in this embodiment, the pitch ΔXP is obtained by reducing the moving speed of the substrate P without changing the oscillation frequency Fa of the clock signal LTC (pulse emission frequency of the beam LB) and the rotation speed of the polygon mirror PM. Can be made smaller than φ / 2, and a multiple exposure mode in which one pixel is exposed in multiple main scans of three or more times can increase the exposure amount during pattern exposure.

  As described above, in the normal exposure mode or the multiple exposure mode, a pattern based on the drawing data is drawn accurately according to the movement amount CX2 of the substrate P. However, in response to the deformation of the substrate P, it is necessary to expand and contract the pattern to be drawn in the sub-scanning direction. Therefore, in the present embodiment, as shown in FIGS. 9A and 9B, the movement amount CX2 of the substrate P counted by the encoder counter unit 106 and the address in the X scan direction (X address value) on the drawing data The drawing magnification in the sub-scanning direction is corrected by shifting the correspondence from the standard relationship. FIG. 9A shows a state in which the increment of the X address value (increase of the first address) corresponds to 10 counts of the movement amount CX2 when the magnification correction is not performed, and FIG. 9B shows the pattern to be drawn. In order to reduce, the X address value increment (increase in address 1) corresponds to the movement amount CX2 corresponding to 9 counts. In this case, the size Px in the X direction of one pixel drawn on the substrate P is reduced to 2.7 μm when the designed pixel size Pxy is 3 μm square. Therefore, the pattern exposed on the substrate P up to the position where the X address value is 10 is reduced by one pixel (3 μm) in the sub-scanning direction with respect to the pattern exposed without correcting the magnification. On the contrary, when the pattern to be drawn is enlarged, the X address value increment (increase in the first address) may be controlled so as to correspond to 11 counts of the movement amount CX2.

  As described above, the X address value is incremented before the movement amount CX2 of the substrate P reaches the designed pixel size Px, or the X address value is incremented when it exceeds the designed pixel size Px. The drawing magnification can be switched to reduction or enlargement by selecting. Further, the timing (pixel position in the X scan direction) for changing the relationship between the design dimension Px and the movement amount CX2 in the sub scanning direction of one pixel from the reference state does not have to be performed for all X address values. While the X address value advances to No. 10, the X address value is incremented by 10 counts (reference state) of the movement amount CX2, and when the X address value becomes 11th, 9 counts (or 11) of the movement amount CX2 is reached. The X address value is incremented by (count), and when the X address value becomes the 12th, the X address value is incremented again by 10 counts (reference state) of the movement amount CX2, and the next 20th X address You may make it continue to a value. Such correction of the drawing magnification in the sub-scanning direction (% or ppm) may not be able to ensure good overlay accuracy and splicing accuracy by just making it uniform within one exposure region W of the substrate P. During the exposure of the area W in the sub-scanning direction, it is necessary to gradually shift to a different magnification correction amount.

  FIG. 10 is a diagram illustrating control when changing to a different drawing magnification during the drawing operation. In FIG. 10, when the magnification is not corrected, it is assumed that one pixel corresponds to 10 counts of the movement amount CX2, and the movement amount CX2 is about 90 counts from the drawing start position Wst. It is assumed that the drawing magnification is set to 1.0 (initial value) at the drawing start position Wst, and the enlargement magnification change point Xm1 is set to a position where the movement amount CX2 becomes 65 counts. The magnification change point Xm1 is estimated from, for example, the arrangement state of the plurality of alignment marks MK1 to MK4 on the substrate P detected by the alignment microscope AM1m. The magnification change point Xm1 is managed by the distance, that is, the movement amount CX2 measured by the encoder counter unit 106. However, as shown in FIG. 10, the magnification change point Xm1 is a period in which the pixel data string DLn corresponding to the X address value No. 6 is drawn, and the magnification is changed so that the drawing magnification is corrected immediately from the magnification change point Xm1. When the movement amount CX2 from the change point Xm1 is 9 counts or 11 counts, the X address value is incremented, and the X address value becomes the seventh pixel data string in the middle of drawing (spot scanning) of the sixth pixel data string DLn. The pixel is switched to DLn, and the pixel corresponding to the sixth pixel data string DLn is drawn halfway or missing. That is, the continuity of pixels (patterns) in the sub-scanning direction is impaired. With respect to the sub-scanning direction, when one pixel is drawn by two spot scans so as to overlap with 1/2 of the size φ of the spot light SP, or the transport speed Vt of the substrate P is decreased and the sub-scan is performed. Even in the multiple drawing mode in which one pixel is drawn by spot scanning three times or more with respect to the direction to increase the exposure amount, the pixel of the X address value depends on the position of the magnification change point Xm1 within the X address value. The data string DLn is missing, or the exposure amount is insufficient (can cause disconnection).

  Therefore, in the present embodiment, as shown in the lower part of FIG. 10, the drawing control unit (control unit) 100 displays the fifth X address value and the sixth X address value at which drawing ends normally immediately before the initial magnification change point Xm1. The position Xm1 ′ (60th count) on the movement amount CX2 located at the boundary with the X address value is set as a new magnification change point (new change point) in the calculation. The pixel data string DLn of the sixth X address value read from the drawing data storage unit 108 from the time when the movement position of the substrate P reaches the position Xm1 ′ is shown in FIG. 8 every time the movement amount CX2 advances 11 counts. The indicated signal XA2 (pulse) is generated and the X address value is incremented. Thereafter, until the next magnification change point, the generation of the signal XA2 (increment of the X address value) is performed every time the movement amount CX2 advances by 11 counts (9 counts in the case of reduction). Then, at the next magnification change point set on the movement amount CX2, a new magnification change point (new change point) is similarly set in the calculation. Here, the new change point (position Xm1 ′) is the position before the original magnification change point Xm1, but the pixel data string DLn of the sixth X address value drawn at the original magnification change point Xm1 is Drawing is performed with the same magnification correction value as that of the pixel data string DLn of the fifth X address value, and the 70th count for completing the drawing of the pixel data string DLn of the sixth X address value is set as the new change point Xm1 ′. You can also

Here, the magnification coefficient set at the drawing start position Wst at which the movement amount CX2 becomes zero is set to ΔMx (0), the first magnification change point (position) on the movement amount CX2 is set to Xm1, and the position Xm1 and subsequent positions. The magnification coefficient is ΔMx (1), the X address value of the current pixel data string DLn being drawn is XA2 (1), and the new change point (position) on the movement amount CX2 obtained by changing the position Xm1 is Xm1 ′. And Further, the magnification coefficient (correction coefficient) ΔMx (0), ΔMx (1) is, for example, any one of count numbers 9, 10, and 11 of the movement amount CX2 set per pixel. In addition, an offset value (X address value at the previous new change point) set for calculating the new change point (position) Xm2 'where the magnification correction is performed next to the new change point Xm1' is performed. Let XAo. When set in this way, the new change point Xm1 ′ is calculated by the following equation (1).
Xm1 ′ = Wst + {XA2 (1) −XAo} · ΔMx (0) (1)

  Here, as shown in FIG. 10, the movement amount CX2 of the drawing start position Wst is zero, the X address value XA2 (1) of the current pixel data string DLn being drawn is 6, and the offset value XAo is zero. Since the magnification coefficient ΔMx (0) is 10 counts, the new change point Xm1 ′ is the 60th count.

Thus, after the magnification coefficient is changed from ΔMx (0) to ΔMx (1) at the new change point Xm1 ′, the X address value XA2 is incremented every 11 counts of the movement amount CX2, and the X address value XA2 Are read out in the order of No. 7, No. 8, No. 9,..., And pattern drawing is performed. Then, as shown in FIG. 11, the next magnification change point Xm2 is designated, for example, at the 118th count (11th pixel data string DLn) on the movement amount CX2, and from the magnification change point Xm2, the magnification coefficient ΔMx (1 ) And a different magnification coefficient ΔMx (2). Here, the magnification coefficient ΔMx (2) is set to an initial value of 10 counts for not performing magnification correction, and the X address value of the current pixel data string DLn that is being drawn is XA2 (2). . In this case, the new change point Xm2 ′ shown in FIG. 11 is calculated by the following equation (2).
Xm2 ′ = Xm1 ′ + {XA2 (2) −XAo} · ΔMx (1) (2)

  Here, as shown in FIG. 11, the previous new change point Xm1 ′ is 60, the X address value XA2 (2) of the current pixel data string DLn being drawn is 11, and the offset value XAo (ie, Since the X address value XA2 (1)) at the previous new change point Xm1 ′ is 6 and the magnification coefficient ΔMx (1) is 11 counts, the new change point Xm2 ′ is calculated as the 115th count. The drawing of the pixel data string DLn whose X address value XA2 (2) is No. 11 is incremented when the movement amount CX2 advances by 10 counts, and the drawing data of the next address (here 12th) is drawn. Control to access (read) the column. 10 and 11 exemplify the case where the pixels in the X scan direction from the new change point (position) Xm1 ′ to the new change point Xm2 ′ are expanded, but in the case of reduction, the movement amount CX2 Is incremented by 9 counts, the signal XA2 (pulse) is generated and the X address value is incremented.

  FIG. 12 is a diagram for explaining an example of the magnification change point Xmn set on one exposure region (pattern formation region) W. When viewed on the XYZ coordinate system, the + X direction side is the tip in the exposure region W. As the portion (drawing start point Wst), the position detection of the plurality of alignment marks MK1 to MK4 by the alignment microscopes AM11 to AM14 and the drawing (exposure) proceed sequentially in the −X direction. While the substrate P is moving in the + X direction at a constant speed, magnification correction information (magnification change point Xmn, magnification factor ΔMx, etc.) in the sub-scanning direction (X direction) based on the position detection results of the alignment marks MK1 to MK4 ) Are generated sequentially. For example, the alignment marks MK1 and MK4 arranged on both sides in the Y direction of the exposure region W are provided at an interval of 10 mm in the design along the X direction. In the measurement of the magnification error using the alignment microscopes AM11 to AM14, an interval between at least two alignment marks MK1 arranged adjacent to each other in the X direction and an interval between at least two alignment marks MK4 arranged adjacent to each other in the X direction are the encoders. It is obtained based on the count value in the counter circuit corresponding to each of EN1a and EN1b, and is compared with the designed interval (10 mm) to obtain the magnification error (%, ppm).

  In FIG. 12, the drawing start position Wst of the exposure area W is set to a magnification change point Xm0 at which the initial magnification coefficient ΔMx (0) is set. In the case of this type of flexible long substrate P, even in the vicinity of the drawing start position Wst in the exposure region W, depending on the change in the transport state of the substrate P until just before being supported by the rotary drum DR, the sub-scanning direction A large magnification error may occur. Therefore, in order to obtain the initial magnification factor ΔMx (0), alignment marks MK1 to MK4 (the blank portion or the previous one) are arranged by the alignment microscopes AM11 to AM14 before the drawing start position Wst of the exposure area W. The drawing control unit 100 calculates the magnification coefficient ΔMx (0) at the magnification change point Xm0 (drawing start position Wst) in consideration of the measurement result.

  Thereafter, as the substrate P moves in the + X direction, the alignment microscopes AM11 and AM14 sequentially detect the positions of the alignment marks MK1 and MK4 and measure the magnification error. As a result, the drawing control unit (magnification setting) When the initial magnification factor ΔMx (0) is to be corrected, the control unit 100 sets a new magnification factor ΔMx (1) and a magnification change point Xm1 to be corrected. After the position detection of the alignment marks MK1 and MK4 by the alignment microscopes AM11 and AM14 and the measurement of the magnification error are started, the drawing start point Wst of the exposure region W is an odd number when the substrate P moves in the + X direction by a certain distance. Pattern lines SL1, SL3, and SL5, pattern drawing is performed with the magnification coefficient ΔMx (0) in the sub-scanning direction, and thereafter, the drawing start positions Wst of the exposure area W are even-numbered drawing lines SL2, SL4, SL6 is reached, and pattern drawing is performed with a magnification coefficient ΔMx (0) in the sub-scanning direction.

  As described above, the magnification error in the sub-scanning direction is sequentially measured as the substrate P moves in the + X direction. For example, as shown in FIG. 12, the magnification change points Xm2 to Xm5 and the magnification coefficient ΔMx (2) to ΔMx (5) is sequentially set. In FIG. 12, the magnification coefficients ΔMx (0) to ΔMx (5) and the magnification change points Xm0 to Xm5 are set for each of the six regions in the X direction in the exposure region W. For example, The magnification coefficient ΔMx (n) and the magnification change point Xmn may be set for each interval (for example, 10 mm) in the X direction between the alignment marks MK1 and MK4 or for every 1/2 (5 mm) thereof. . Thus, when the magnification change point Xmn is set finely in the sub-scanning direction, for example, while the substrate P moves 10 mm (or 5 mm) in the + X direction, the magnification coefficient ΔMx (n) is set to enlargement or reduction. Then, while the substrate P continues to move 10 mm (or 5 mm) in the + X direction, the magnification factor ΔMx (n + 1) may be set to the same magnification (no enlargement or reduction). In this embodiment, the drawing magnification can be finely corrected with respect to the magnification error due to the expansion and contraction of the substrate P in the sub-scanning direction as described above, and the overlay accuracy is satisfactorily maintained over the entire exposure area W. be able to.

[Modification] FIG. 13 is a diagram (time chart) for explaining a modification of the calculation sequence for correcting the drawing magnification in the sub-scanning direction executed by the drawing control unit 100 shown in FIG. Here, the calculation sequence for the scanning unit U1 will be described as a representative, but the same sequence is executed in the other scanning units U2 to U6. The drawing control unit 100 sequentially and repeatedly executes the two processes A and B shown in FIG. The process A is sequentially executed in response to the origin signal SZ1 (pulse signal) sent from the scanning unit U1, and the process B is generated with a cycle Tpk shorter than the cycle Tpx where the origin signal SZ1 (pulse signal) is generated. Are sequentially executed in response to the timing signal (internal clock pulse signal) SK1. Here, it is assumed that the cycle Tpk is set to about 1/3 of the cycle Tpx. The longest processing time of the routine processing of processing B is set so as to be within the cycle Tpk.

The processing A executed for each pulse of the origin signal SZ1 includes a step SA1 for obtaining the movement amount CX2 (movement distance from the drawing start position Wst of the substrate P) as described in FIGS. And step SA2 for calculating and setting the X address value XA2 (n) in the drawing data memory corresponding to CX2. The process B executed for each pulse of the signal SK1 includes step SB1 for obtaining the movement amount CX2, and the obtained movement amount CX2 (current position) is the next magnification change point as described in FIGS. In step SB2 for determining whether or not Xmn has passed, and when CX2 ≧ Xmn, the offset value XAo of the X address value and the new change point Xmn ′ described above are calculated, and the next magnification coefficient ΔMx (n) Step SB3 to be changed to Note that the calculation of the X address value XA2 (n) in step SA2 is the following integer calculation with the decimal point rounded off or rounded down, where ΔMx (n−1) is the magnification factor set when the process A is executed:
XA2 (n) = {CX2-Xm (n-1) '} / ΔMx (n-1) + XAo
Calculated by

  In this way, by paralleling the processes A and B for each cycle Tpx of the origin signal SZ1 and for each cycle Tpk shorter than the cycle Tpx of the origin signal SZ1, at the drawing magnification change point Xmn in the sub-scanning direction, Drawing for one pixel in the sub-scanning direction is not halfway or lost, and precise pattern drawing is performed.

[Second Embodiment]
In the previous first embodiment or modification, the drawing start by the spot light SP along each of the drawing lines SL1 to SL6 is started by the origin sensor OPn (OP1 to OP6) as the detection sensor shown in FIGS. ) Are generated immediately after the origin signals SZn (SZ1 to SZ6) are generated. However, in actuality, when the origin signal SZn (SZ1 to SZ6) is generated, the spot signal SPn is generated so that the pattern drawing is started after the spot light SP travels about 1 mm to several mm on the substrate P. Is provided with a delay circuit (hardware or software) for starting drawing after a predetermined delay time ΔTss. As exemplified above, the scanning time Tsp of one scan of the spot light SP along the drawing line SLn is about 200 μsec, and the maximum scanning length of the spot light SP on the substrate P is 32 mm (effective drawing range 30 mm). Assuming that an additional range of 1 mm is provided before and after the scanning speed Vs, the scanning speed Vs of the spot light SP is 160 μm / μsec. Therefore, if the delay time ΔTss is changed by ± 1 μsec with respect to the initial value, the pattern drawn on the substrate P can be shifted by ± 160 μm in the main scanning direction (Y direction). Usually, the time from the generation of the origin signal SZn to the actual start of drawing is set as short as possible. Therefore, when the delay time ΔTss is decreased from the initial value, the origin signal SZn is generated from the time of generation. The interval time until the drawing start time is shortened. Therefore, the time for calculating the address value in the memory of the pixel data string DLn to be drawn before the drawing start time and calculating various correction values (magnification correction amount, Y position shift amount, etc.) It may be longer than the interval time, and a pattern to be drawn may be partially lacked, and may be greatly disturbed.

  Therefore, in the present embodiment, as shown in FIG. 14, the pixel data string DLn to be drawn by one scan of the spotlight SP (read address processing, access address calculation process, one column of the pixel data string DLn is a bit. 1 cycle of the pulse of the origin signal SZn (second detection signal) generated at the timing of actually drawing with the spot light SP of the beam LBn for the preparation process such as the correction processing and the like. It is executed in response to a pulse (first detection signal) generated just before Tpx. FIG. 14 is a time chart showing the generation timing of the origin signal SZ1 from the scanning unit U1, the drawing timing (signal SE1 indicating the actual drawing period), and the calculation timing in time series. The pulse of the origin signal SZ1 is generated at a constant cycle Tpx in the order of the continuous reflecting surfaces RPa, RPb, RPc, RPd,. In general drawing control, for example, a predetermined delay from the time of generation of one pulse of the origin signal SZ1 generated immediately before the rotation angle at which the reflecting surface RPa (RPb to RPd. After the time ΔTss, for example, drawing is performed based on the pixel data string DL1a corresponding to one X address value. That is, in general drawing control, as indicated by the calculation timing A, it is necessary to perform access processing and calculation processing of the pixel data string DL1a to be drawn within the delay time ΔTss.

  In FIG. 14, DL1a drawing (drawing timing based on the pixel data string DL1a, the same applies hereinafter), DL1b drawing, DL1c drawing,... , RPb, RPc... However, the X address value is incremented when the scanning along the drawing line SL1 of the spot light SP is performed twice or a certain number of times or more, so that two or more continuous reflecting surfaces RPa of the polygon mirror PM, With RPb, RPc,..., The same pixel data string DL1 is repeatedly drawn a predetermined number of times. Further, in FIG. 14, the pulse of the origin signal SZn generated at the timing when the above-described preparation processing of the pixel data string DLn to be drawn with one scan of the spot light SP is actually drawn with the spot light SP of the beam LBn ( This is executed in response to a pulse (first detection signal) generated one cycle Tpx before the second detection signal), but this is not limited to one cycle Tpx but one cycle Tpx or more. May be a time point just before the predetermined time (for example, a pulse of the origin signal SZn generated before two cycles or more). The time before the preparation process is started is set according to the time required for the preparation process.

  In the present embodiment, as shown at the calculation timing B in FIG. 14, the access processing and calculation processing of the pixel data string DL1 are performed in advance in response to one pulse of the origin signal SZ1, and the next of the origin signal SZ1 is performed. The actual drawing is started in response to the pulse. In this way, it is possible to secure the time for performing the access process and the arithmetic process for the pixel data string DL1 up to the time of the period Tpx, and to reliably execute the access process and the arithmetic process for the pixel data string DL1. it can. Furthermore, in the case of the operation timing A, the delay time ΔTss cannot be shortened to a time shorter than that because it is necessary to secure a minimum time for the access processing of the pixel data string DL1. For this reason, the range in which the position of the pattern to be drawn can be shifted in the Y direction is limited, but in this embodiment, the delay time ΔTss can be set from zero. Therefore, even when the position and distortion in the width direction of the substrate P are large, it is possible to obtain good overlay accuracy.

  FIG. 15 is a block diagram illustrating an outline of a part of the circuit configuration provided in each of the drawing control unit 100 and the drawing data storage unit 108 in FIG. 6 in order to perform the control described in FIG. Also here, the drawing control unit 100 and the drawing data storage unit 108 are representatively provided corresponding to the scanning unit U1, and the drawing data storage unit 108 has pattern data to be drawn by the drawing line SL1. It shall be remembered. The drawing data storage unit 108 stores memory areas 108A0, 108A1, 108A2,... For storing pixel data strings DL1a, DL1b, DL1c,... For one drawing line in the main scanning direction accessed with an X address value. A selection unit 108B that selects one of the memory areas 108A0, 108A1, 108A2,... (Hereinafter also collectively referred to as 108An) in accordance with the X address value designated by the drawing control unit 100; An AND gate unit 108C for inputting the bit data of the pixel data string DL1 serially output from one memory area selected from 108An and the drawing switch signal SHT described with reference to FIGS. 6 and 7, and a memory area A Y address record for generating a Y address value of one selected memory area of 108An. It comprises a static 108D, and a pixel shift signal (pulse signal) for supplying BSC AND gate portion 108E for incrementing the Y address value to the Y address register 108D. In FIG. 15, the selection unit 108B applies the pixel data string DL1a from the memory area 108A0 corresponding to address 0 of the X address value to the AND gate unit 108C, and the bit stream (serial 2 of the pixel data string DL1a). The value signal) is supplied as a modulation signal to the drawing optical element AOM1 for the scanning unit U1 via the AOM driving unit 110 in FIG.

  The drawing control unit 100 includes a delay time generation unit 100A that inputs the origin signal SZ1 from the scanning unit U1 via the polygon mirror driving unit 102 in FIG. The delay time generation unit 100A outputs a signal SE1 as shown in FIG. 14 after a specified delay time ΔTss has elapsed from the time when one pulse of the origin signal SZ1 is generated. The signal SE1 is sent to one input of the AND gate unit 108E in the drawing data storage unit 108, and a pixel shift signal (pulse) BSC applied to the other input of the AND gate unit 108E is passed to the Y address register 108D. Switch at high speed. The function of the delay time generation unit 100A may be realized by program processing by the CPU of the drawing control unit 100, or may be realized by hardware by FPGA (Field Programmable Gate Array).

  Here, the delay time ΔTss set in the delay time generation unit 100A is a delay time from the time when the origin signal SZ1 is generated, but the delay time generation unit 100A itself generates a constant initial delay time ΔTd0. When configured, the delay time ΔTss ′ set in the delay time generator 100A may be ΔTss ′ = ΔTss−ΔTd0.

  In the above configuration, when one pulse of the origin signal SZ1 as shown in FIG. 14 is input to the delay time generation unit 100A, the delay time generation unit 100A rises to the H level after the delay time ΔTss and spots along the drawing line SL1. A signal SE1 that falls to L level is generated when a time that is slightly longer than the scanning time of the light SP and shorter than the period Tpx in which the origin signal SZ1 generates a pulse has elapsed. The AND gate unit 108E supplies a pixel shift signal (pulse signal) BSC as shown in FIG. 8 to the Y address register 108D only while the signal SE1 is at the H level. Thereby, the Y address register 108D sequentially increments the Y address value for designating the address in the memory area 108A0 in response to the pulse of the pixel shift signal BSC. In the case of FIG. 15, since the address specified as the X address value is address 0, the pixel data string DL1a read out serially from address 0 (bit) in the memory area 108A0 is passed through the AND gate unit 108C. During scanning of the spot light SP along the drawing line SL1, the intensity of the spot light SP is modulated in accordance with the pixel data string DL1a at address 0 in the sub-scanning direction (X address value is 0) while being sent to the AOM driving unit 110. Is done.

  As exemplified above, when the scanning time Tsp of one scanning of the spot light SP along the drawing line SLn is about 200 μsec and the maximum scanning length of the spot light SP on the substrate P is 32 mm, the delay time ΔTss is If it is changed by ± 1 μsec (1000 nsec), the pattern drawn on the substrate P is shifted by ± 160 μm in the main scanning direction (Y direction). In practice, the adjustment resolution of the position shift is determined by the balance between the overlay accuracy and the minimum dimension (minimum line width) of the pattern to be drawn. For example, assuming that the minimum dimension is 15 μm and the overlay accuracy is about 1/5 of the minimum dimension, ± 3 μm, the position shift adjustment resolution is also required to be about 3 μm. Therefore, the delay time generation unit 100A may be configured to be able to set the delay time ΔTss (or ΔTss ′) with a resolution of 18.75 nsec (= 3 μm × 1000 nsec / 160 μm) or less, for example, 9 nsec. When measuring the delay time ΔTss (or ΔTss ′) by the number of clock pulses, if a 107.25 MHz clock signal is generated, the pulse period of the clock signal is 9.324 nsec on the substrate P. This can correspond to a position shift of 1.5 μm.

  FIG. 16 is a chart showing an example in which the position shift of the drawing pattern in the main scanning direction (Y direction) described with reference to FIGS. It is. In FIG. 16, the horizontal axis represents the time from the drawing start position Wst of the exposure area W or the movement position in the X direction. Here, the movement amount CX2 (or CX1) is up to 500, which is a count value (one count corresponds to, for example, 0.3 μm) digitally counted from the drawing start position Wst by the counter circuit corresponding to the encoder EN2 (or EN1). It is assumed that the X address value is incremented by one address every 10 counts of the movement amount CX2. The Y shift change points XS0, XS1, and XS2 are exposure regions W (background patterns) calculated by the drawing control unit 100 based on positional information of the alignment marks MK1 to MK4 detected by the alignment microscopes AM11 to AM14 immediately before starting drawing. ) Is a change in position shift to cope with the deformation. The shift rates ΔYS0, ΔYS1, and ΔYS2 represent change rates (inclinations) ψ0, ψ1, and ψ2 of position shifts obtained by linear approximation between the position shift amounts at two successive Y shift change points XSn and XSn + 1. .

  In FIG. 16, it is assumed that at the drawing start position Wst (time Tx0, position X0), the Y position of the exposure region W is shifted by −YS0 in the Y direction from the designed initial position (0). The initial position (0) is drawn in the main scanning direction set on the substrate P when the delay time generator 100A transitions the signal SE1 to the H level after the initial delay time ΔTd0 from the generation of the pulse of the origin signal SZ1. This is the starting point. As the substrate P moves in the sub-scanning direction (X direction), the alignment microscopes AM11 to AM14 and the encoder EN1 cooperate to sequentially detect the positions of the alignment marks MK1 and MK4. The drawing control unit 100 calculates the position shift amount based on the detected positions of the detected plurality of alignment marks MK1 and MK4. When the drawing control unit 100 determines that the tendency of the position shift in the Y direction of the exposure area W at the position X1 has changed, the position shift amount + YS1 from the initial position (0) at the position X1 (time Tx1), The count value of the movement amount CX2 (CX1) from the position X0 to the position X1 using the difference value from the position shift amount −YS0 from the initial position (0) at the position X0 (time Tx0) as the drawing start position Wst as a numerator. The shift rate ΔYS0 (change rate ψ0) is calculated with the denominator as the denominator.

  As shown in FIG. 3, a plurality of alignments are performed with respect to the movement direction of the substrate P between the positions of the detection regions Vw11 and Vw14 of the alignment microscopes AM11 and AM14 and the positions of the drawing lines SL1, SL3, and SL5. Marks MK1 and MK4 are formed. In the case of FIG. 3, before the positions to be drawn in the exposure area W reach the drawing lines SL1, SL3, and SL5, the alignment microscopes AM11 and AM14 are respectively provided at three or four places provided at intervals Dh in the X direction. Each position of the alignment marks MK1 and MK4 can be detected. Therefore, based on the position detection results of the plurality of alignment marks MK1 and MK4, the position shift amount in the Y direction of the exposure region W and the change rate of the position shift can be obtained before pattern drawing.

  Similarly, each of the plurality of alignment marks MK1 and MK4 is sequentially detected as the substrate P is moved, and the tendency of the position shift in the Y direction of the exposure region W again at the next position X2 (time Tx2) again. If it is determined that the position has changed, the difference value between the position shift amount + YS2 from the initial position (0) at the position X2 and the position shift amount + YS1 at the position X1 (time Tx1), which is the previous change point, is calculated. A shift rate ΔYS1 (change rate ψ1) is calculated using the count value of the movement amount CX2 (CX1) from position X1 to position X2 as the numerator. In this way, the change in the position shift amount in the Y direction of the exposure area W is approximately and sequentially obtained corresponding to the movement amount CX2 (CX1) of the substrate P in the sub-scanning direction (X direction). When the position shift amounts -YS0, + YS1, + YS2 at the positions X0, X1, and X2 are obtained and the shift rates ΔYS0, ΔYS1,... Are obtained, the drawing control unit 100 determines the position shift amount −YS0 at the drawing start position Wst. The delay time ΔTss0 corresponding to the value and the shift rate ΔYS0 are set in the delay time generation unit 100A. The delay time generation unit 100A starts from the time when the drawing line SL1 (SL3, SL5) and the drawing start position Wst on the substrate P coincide with each other, in the case of FIG. 16, the delay time ΔTss is shifted from the initial value ΔTss0 to the shift rate ΔYS0. As you go up, it will be increased sequentially. When the substrate P moves to the position X1, the drawing control unit 100 sets the shift rate ΔYS1 in the delay time generation unit 100A with the value of the delay time ΔTss1 corresponding to the position shift amount + YS1 at the position X1 as an initial value. . Thereby, the pattern exposed from the position X0 on the substrate P is sequentially corrected and drawn at the drawing start timing in response to the origin signal SZn so as to follow the tendency of the position shift of the exposure region W in the Y direction.

  As described above, the entire drawing line SLn has a high resolution in the Y direction in units of pixels in the sub-scanning direction (or one scanning unit by the spot light SP) in accordance with the tendency of the position shift in the main scanning direction of the exposure region W. (For example, about 1/2 of the pixel size) and the overlay accuracy can be greatly improved over the entire exposure area W.

  [Modification 1] In addition to the position shift in the Y direction of the exposure area W as described above, the dimension in the width direction (main scanning direction) of the exposure area W is sufficient according to the position of the exposure area W in the sub-scanning direction. In some cases, the expansion and contraction may change within a range of several ppm to several hundred ppm. Such a tendency of expansion and contraction in the main scanning direction of the exposure region W can also be estimated by detecting the positions of the alignment marks MK1 to MK4 by the alignment microscopes AM11 and AM14. As described with reference to FIGS. 6 and 7, the drawing magnification correction for the expansion and contraction of the exposure area W in the main scanning direction is performed so that the size of the pattern drawn in each drawing line SLn is finely adjusted. This is executed by sending information TMg and CMg for correcting the drawing magnification from the control unit 100 to the light source device LS.

  By sequentially changing values set in the light source device LS as the information TMg and CMg in association with the movement amount CX2 of the substrate P, the dimension in the width direction of the exposure region W seems to change nonlinearly with respect to the longitudinal direction. Even in such a case, high overlay accuracy can be obtained over the entire surface in the exposure region W. Further, the above-described drawing magnification correction for the expansion / contraction change of the exposure area W in the sub-scanning direction, the drawing position correction for the position shift of the exposure area W in the Y direction, and the drawing magnification correction for the expansion / contraction of the exposure area W in the width direction; By executing at least two of these corrections in parallel, a pattern can be drawn with good overlay accuracy even for non-linear deformation of the entire exposure region W.

  [Modification 2] In the first embodiment and the second embodiment, the oscillation frequency Fa of the beam LB from the light source device LS and the scanning speed Vs of the spot light SP are on the substrate P of the spot light SP. Is set to be overlapped in the main scanning direction at 1/2 of the size φ, and the pixel unit is set to be drawn by two spots of the spot light SP. Further, when the drawing magnification is corrected, the clock signal LTC is set so that the interval between two spot lights SP continuous in the main scanning direction is slightly expanded and contracted at a correction point corresponding to a specific pixel. The period of the pulse was expanded and contracted. However, the oscillation frequency Fa of the beam LB from the light source device LS is increased, the pixel unit is controlled to be drawn with a large number of spot lights SP (pulse light), and the pixel located at the correction point for correcting the drawing magnification is set. On the other hand, the number of pulses of the spot light SP may be increased or decreased. For example, the beam LB from the light source device LS according to the first embodiment is oscillated at 400 MHz, which is four times 100 MHz, and main scanning is performed on pixels (normal pixels) positioned other than the correction point for the drawing magnification. With respect to the direction, drawing is performed with spot light SP of 8 pulses per pixel, and for the pixel (correction pixel) located at the correction point, with respect to the main scanning direction, spot light SP of 7 pulses for reduction and 9 pulses for enlargement. Draw with. In this case, the clock signal LTC for pulsing the beam LB may remain at a constant period (in the case of 400 MHz, the period is 2.5 nS) without partially finely adjusting the period.

  As described above, in the case of the drawing magnification correction in the main scanning direction in which the number of pulses of the spot light SP per pixel is adjusted, the access to the image data (pixel data string) stored in the drawing data storage unit 108 is related to the normal pixel. When the clock pulse of the clock signal LTC is counted 8 times, the Y address value of the memory is incremented by one. When the clock pulse of the clock signal LTC is counted 7 or 9 for the correction pixel, the Y address value of the memory is incremented by 1. Just do it. As described above, when the pixel size Pxy is drawn with 3 μm square when the pixel size Pxy in the design is 3 μm square when the pixel is drawn with 8 pulses of spot light SP as a standard in the main scanning direction, the correction pixel is reduced when reduced. An image is drawn at about 2.63 μm (7/8 × 3 μm) in the main scanning direction, and at about 3.38 μm (9/8 × 3 μm) in the main scanning direction at the time of enlargement.

  [Modification 3] In both the first and second embodiments, a direct-drawing maskless exposure machine that performs one-dimensional scanning of the spot light SP projected onto the substrate P by the polygon mirror PM. Although, for example, as disclosed in Japanese Patent Application Laid-Open No. 2008-182115, even a maskless exposure machine that draws a pattern using a digital micromirror device (DMD) and a microlens array. Good. In that case, if a mechanism for precisely moving the substrate P in the sub-scanning direction and a measuring system such as an encoder or a length measuring interferometer that measures the amount of movement with a resolution less than the pixel size are provided, The drawing magnification correction in the sub-scanning direction described in the embodiment and the drawing position shift correction in the main scanning direction described in the second embodiment can be similarly performed. In the case of a maskless exposure apparatus having an exposure head unit including a DMD and a microlens array, whether the light beam deflected by each of a number of micro movable mirrors of the DMD is incident on each of the corresponding lenses of the microlens array The substrate P is moved in the sub-scanning direction while the intensity of a large number of spot lights SP distributed on the substrate P is modulated (on / off) by switching at high speed based on the drawing data. Let me draw a pattern. In the first embodiment, the second embodiment, and the first to third modifications, the substrate P is moved in the sub-scanning direction, but the exposure head side (the entire scanning unit Un) is constant. It may be moved at a predetermined speed in the sub-scanning direction over the distance.

  [Modification 4] In the first embodiment and the second embodiment, as shown in FIG. 6, the rotational angle position of the rotary drum DR counted by the encoder counter unit 106, that is, the length of the substrate P is long. Based on the movement position (or movement amount) of the direction, the address value of the drawing data corresponding to each of the scanning units U1 to U6 stored in the drawing data storage unit 108 is designated every time the spot light SP is scanned. Thus, data reading is performed, and pattern drawing is performed on each of the drawing lines SL1 to SL6. However, as described above, each counter circuit that is provided in the encoder counter unit 106 and counts the two-phase signals from each of the encoders ENja (EN1a to EN4a) and ENjb (EN1b to EN4b) has a Z-phase mark ZZ. Is reset to zero. Therefore, if the address value of the drawing data stored in the drawing data storage unit 108 is directly generated by the count value (count value) counted by the encoder counter unit 106, a large jump may occur in the address value at the time of zero reset. is there. In order to avoid this, the address value does not fly by zero reset while each of the scanning units U1 to U6 performs the drawing operation on one exposure area W on the substrate P shown in FIG. In addition, for example, monitoring is sequentially performed by program processing by a microprocessor (CPU) unit in the drawing control unit 100, and the count value of the counter circuit in the counter unit 106 immediately before being reset to zero is latched as an offset value. The drawing data address value stored in the drawing data storage unit 108 may be generated based on a value obtained by adding the latched offset value to the count value counted by the counter circuit in the counter unit 106.

  In that case, the microprocessor (CPU) unit in the drawing control unit 100 sequentially adds the latched offset value and the count value sent from the encoder counter unit 106 thereafter, and the drawing data storage unit 108. An address counter (register) for accessing the drawing data to be drawn in the internal memory is provided. As a result, this address counter functions as a counter circuit that is not reset to zero by the Z-phase mark ZZ of the encoder scale unit SDa (SDb), and is generated even if each counter circuit in the encoder counter unit 106 is reset to zero. The continuity of address values can be maintained.

  However, the microprocessor (CPU) unit in the drawing control unit 100 always monitors the occurrence of zero reset of each counter circuit in the encoder counter unit 106, latches the offset value at the time of zero reset, and outputs from the encoder counter unit 106. An addition operation between the count value and the offset value is performed by interrupt processing, and the series of processing may be delayed depending on the timing of interrupt generation. Therefore, a second counter circuit (functioning as an address counter for the memory in the drawing data storage unit 108) that has the same configuration as each counter circuit in the encoder counter unit 106 and is not reset by the Z-phase mark ZZ is separately provided. Provide. This second counter circuit has the number of digits (bit number) sufficient to count the grid scale of the scale portion SDa (SDb) over one rotation of the rotating drum DR, preferably over several rotations. The second counter circuit (s) counts the two-phase signals from the encoders ENja (EN1a to EN4a) and ENjb (EN1b to EN4b), respectively. The reset of the count value is performed by each of the scanning units U1 to U6. This is performed once in response to, for example, the origin signal SZn (SZ1 to SZ6) at the position of the drawing start point in the longitudinal direction of the exposure region W on the substrate P. The reset value at that time is made to correspond to the top address value of the memory in which the drawing data of the pattern drawn in the exposure area W is stored, for example. As described above, by providing the second counter circuit (s), the microprocessor (CPU) unit in the drawing control unit 100 performs an interrupt process in response to the zero reset of each counter circuit in the encoder counter unit 106. There is no need, and the drawing data can be read from the memory in the drawing data storage unit 108 without skipping continuously in time. Note that six second counter circuits (plural) are provided corresponding to each of the scanning units U1 to U6, and each second counter circuit has origin signals SZ1 to SZ1 from the corresponding scanning units U1 to U6. The SZ6 pulse may be counted from the drawing start time in the longitudinal direction of the exposure area W, and an address value for the memory in the drawing data storage unit 108 may be generated.

DESCRIPTION OF SYMBOLS 10 ... Device manufacturing system 12 ... Substrate conveyance mechanism 14 ... Exposure head 16 ... Control apparatus 20 ... Pulse light generation part 22 ... Control circuit 100 ... Drawing control part 102 ... Polygon mirror drive part 104 ... Alignment part 106 ... Encoder counter part 108 ... Drawing data storage unit 110 ... AOM driving unit 112 ... drive control unit AOMn ... drawing optical element BDU ... beam distributing unit DR ... rotating drum EX ... exposure device LBn ... beam LS ... light source device OP1 ... origin sensor opa ... beam light transmission system opb ... Beam receiving system P ... Substrate PM ... Polygon mirror SP ... Spot light Un ... Scanning unit

Claims (12)

An exposure head unit that scans a spot of a light beam modulated based on drawing data in the main scanning direction on the substrate, and corresponds to the drawing data on the substrate by moving the substrate in the sub-scanning direction A pattern drawing apparatus for drawing a pattern,
A rotating polygon mirror that sequentially reflects the light beam on each of a plurality of reflecting surfaces to scan in the main scanning direction;
An origin sensor that generates an origin pulse signal indicating a drawing start time by the light beam every time each reflecting surface of the rotating polygon mirror is at a predetermined angular position;
When the pattern to be drawn on the substrate is represented by a plurality of pixels decomposed two-dimensionally in the main scanning direction and the sub-scanning direction, pixel data corresponding to each of the plurality of pixels is represented by the spot A data storage unit for storing as a pixel data sequence arranged in the order of scanning;
In response to the first origin pulse signal, until the next second origin pulse signal is generated, designation of the pixel data string to be drawn and predetermined calculation stored in the data storage unit A control unit that executes a preparatory process, and starts a drawing operation by the spot based on the pixel data sequence that has been prepared in response to the second origin pulse signal;
A pattern drawing apparatus. The pattern drawing apparatus according to claim 1,
The control unit includes at least one of a calculation related to correction of the drawing magnification in the sub-scanning direction, a calculation related to correction of the drawing magnification in the main scanning direction, and a calculation related to a shift of the drawing position of the pattern in the main scanning direction. A pattern drawing apparatus that executes one as the predetermined calculation. The pattern drawing apparatus according to claim 2,
In order to emit an ultraviolet beam that has a peak wavelength at a specific wavelength in a wavelength band of 370 nm or less and emits a pulse at a specific frequency Fa of 100 MHz to several hundred MHz, A pulse light source section that oscillates the seed light at the frequency Fa, an optical amplifier that amplifies the seed light, and a wavelength conversion element that receives the amplified seed light and converts it into the wavelength of the ultraviolet beam. A pattern drawing device, further comprising a pulse light source device. It is a pattern drawing apparatus of Claim 3, Comprising:
A photosensitive functional layer having photosensitivity to the light beam from the pulse light source device is formed on the surface of the substrate,
The origin sensor receives a beam transmission system that emits a beam in a wavelength region that is non-photosensitive to the photosensitive functional layer toward a reflecting surface of the rotating polygon mirror, and a reflected beam reflected by the reflecting surface. And a beam receiving system for generating the origin pulse signal. A pattern drawing apparatus for drawing a pattern for an electronic device on a long sheet substrate supported by being curved in a cylindrical shape on an outer peripheral surface of a rotating drum that rotates around a central axis,
A scanning unit for repeatedly scanning a drawing beam for drawing the pattern in a main scanning direction substantially parallel to a direction in which the central axis extends on the sheet substrate by a rotary polygon mirror;
A rotation drive source for rotating the rotary drum so that the sheet substrate moves at a predetermined conveyance speed in the sub-scanning direction intersecting the main scanning direction;
A detection sensor that outputs a detection signal indicating that the drawing beam has reached a time corresponding to a scanning start position in the main scanning direction for each of the plurality of reflecting surfaces of the rotary polygon mirror;
A data storage unit for storing a plurality of drawing data corresponding to the pattern to be drawn while the drawing beam is scanned in the main scanning direction with respect to the sub-scanning direction;
The drawing data to be drawn in response to the second detection signal in a period between the first detection signal output from the detection sensor and the second detection signal output thereafter. Is prepared from the data storage unit, and the pattern is drawn by the drawing beam based on the drawing data that has been prepared in response to the second detection signal. A control unit for controlling
A pattern drawing apparatus. It is a pattern drawing apparatus of Claim 5, Comprising:
The data storage unit divides the pattern to be drawn on the sheet substrate into two-dimensional pixels, and stores a pixel data row corresponding to each of one row of pixels arranged in the main scanning direction as the drawing data. And a pattern drawing device that stores a plurality of the pixel data strings corresponding to the pixels arranged in the sub-scanning direction. It is a pattern drawing apparatus of Claim 6, Comprising:
The controller includes a modulator that starts a modulation of the intensity of the drawing beam based on the pixel data sequence that has been subjected to the preparation processing after a predetermined delay time from the generation of the second detection signal. apparatus. The pattern drawing apparatus according to claim 7,
The detection sensor receives a reflected beam from the reflection surface of the rotary polygon mirror and outputs a detection signal by irradiating the reflection surface of the rotary polygon mirror with a detection beam. Including a light receiving system,
The light receiving system outputs the detection signal when each of a plurality of reflecting surfaces of the rotary polygon mirror has a predetermined angle. It is a pattern drawing apparatus of Claim 8, Comprising:
The said control part is a pattern drawing apparatus which shifts the drawing position of the said pattern in the said main scanning direction by adjustment of the said delay time. It is a pattern drawing apparatus of any one of Claims 5-9,
In order to generate the drawing beam, a pulse light source unit that generates seed light that oscillates in a pulse shape at a predetermined frequency, an optical amplifier that amplifies the seed light, and an ultraviolet light that is incident on the amplified seed light. A pattern drawing apparatus, further comprising: a pulse light source device including a wavelength conversion element that generates pulsed light in a wavelength region. It is a pattern drawing apparatus of Claim 10, Comprising:
A photosensitive functional layer having photosensitivity to the drawing beam from the pulse light source device is formed on the surface of the sheet substrate,
The detection sensor receives a beam transmission system that emits a beam in a wavelength region that is non-photosensitive to the photosensitive functional layer toward a reflecting surface of the rotary polygon mirror, and a reflected beam reflected by the reflecting surface. And a beam receiving system for generating the detection signal. It is a pattern drawing apparatus of any one of Claims 5-11,
The control unit includes, as the preparation process, a calculation process related to correction of the drawing magnification in the sub-scanning direction, a calculation process related to correction of the drawing magnification in the main scanning direction, and a shift of the drawing position of the pattern in the main scanning direction. A pattern drawing apparatus that executes at least one of the arithmetic processing related to the above.

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