JP2017102272A - Beam scanning device, beam scanning method, and pattern drawing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a beam scanning device that can detect deviations of a generation timing of an origin signal due to positional deviation of an origin sensor, and adjust a scan start timing.SOLUTION: A beam scanning device, which first-dimensionally scans spot light on an irradiated surface as projecting the spot light of a beam from a light source device to the irradiated surface of a substrate, comprises: a polygon mirror PM that includes a plurality of reflection planes RP deflecting the beam for the first dimensional scanning; and a plurality of origin sensors (OP1, SOPa1 and SOPb1) that irradiates the reflection plane of the polygon mirror with measurement light Bga, receives reflection light Bgb of the measurement light when the reflection plane comes at a prescribed rotation angle position and thereby outputs an origin signal (SZ1, SZa1 and SZb1). Each of the plurality of origin sensors is configured to: irradiate the mutually different reflection plane of the polygon mirror with the measurement light; and output the origin signal for each different reflection plane.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a beam scanning apparatus, a beam scanning method, and a pattern drawing apparatus that scan a spot light of a beam irradiated on an irradiated surface of an object to draw and expose a predetermined pattern.

  In Patent Document 1 shown below, a photosensitive drum is rotated by rotating a photosensitive drum while projecting a laser beam onto a photosensitive drum and rotating a laser beam in a one-dimensional direction along a scanning line by a rotated polygon mirror. A laser printer that draws a desired pattern or image (characters, figures, photographs, etc.) on a drum is disclosed. It also describes that an origin sensor is provided at the first scanning position on the scanning line, and the drawing start timing and the rotation of the polygon mirror are controlled using an origin pulse that is a detection signal of the origin sensor. Here, around the reflection surface of the polygon mirror that scans (deflects) the laser beam (hereinafter referred to as the deflection reflection surface), it is reflected by an optical system for transmitting the laser beam to the deflection reflection surface or by the deflection reflection surface. An exposure optical system for guiding the laser beam to a photosensitive drum as an object is arranged. Therefore, when the origin sensor is provided in the vicinity of the deflection reflection surface that reflects the laser beam, there is not much space for providing the origin sensor, so it is difficult to stably place the origin sensor. It may deviate slightly from the installation position due to vibration. In this case, the origin signal generation timing is also shifted, and the drawing start timing is also shifted. As a result, the position of the scanning line scanned with the laser beam is shifted (drifted) in the main scanning direction.

JP-A-7-35995

  A first aspect of the present invention is a beam scanning device that projects the spot light of a beam from a light source device onto an irradiated surface of an object while scanning the spot light on the irradiated surface in a one-dimensional manner. A rotating polygon mirror having a plurality of reflecting surfaces for deflecting the beam for the one-dimensional scanning, and measuring light is applied to the reflecting surface of the rotating polygon mirror, and the reflecting surface is at a predetermined rotational angle position. And a plurality of origin sensors that output an origin signal by receiving reflected light of the measurement light, and each of the plurality of origin sensors is directed toward the different reflective surfaces of the rotary polygon mirror. Irradiating the measurement light, the origin signal is output for each of the different reflecting surfaces.

  According to a second aspect of the present invention, there is provided a beam scanning method for projecting spot light of a beam from a light source device onto an irradiated surface of an object while scanning the spot light on the irradiated surface in a one-dimensional manner. A deflection step of deflecting the beam for the one-dimensional scanning by using a rotating polygon mirror; and irradiating measurement light on at least two different reflecting surfaces of the rotating polygon mirror; An output step of outputting at least two origin signals corresponding to each of the at least two reflection surfaces by receiving reflected light of the measurement light when each of the reflection surfaces comes to a predetermined rotation angle position; Including.

  According to a third aspect of the present invention, there is provided a pattern drawing apparatus for drawing a pattern on the object by scanning the beam on the object and modulating the beam according to pattern information during the scanning. The rotating polygon mirror having a plurality of reflecting surfaces for deflecting the beam and the first reflecting surface of the plurality of reflecting surfaces of the rotating polygon mirror are rotated within a predetermined angle range for the scanning. A projection optical system that projects the beam reflected by the first reflecting surface and projects toward the object, and a first time point when the first reflecting surface reaches the predetermined angle range. The first origin detector that outputs the origin signal of the first and the second reflecting surface different from the first reflecting surface among the plurality of reflecting surfaces of the rotary polygon mirror is a first time point representing a predetermined rotational angle position. A second origin detector that outputs a second origin signal; and the first origin detector Based on said a point signal a second origin signal, and a drawing control unit that controls the start timing of modulation of the beam.

It is a schematic block diagram of the device manufacturing system containing the exposure apparatus which performs the exposure process to the board | substrate of embodiment. It is a perspective view which shows the rotating drum shown in FIG. 1 in the state by which the board | substrate was wound. It is a figure which shows the mark for alignment formed on the drawing line of a spot light, and a board | substrate. It is a principal part enlarged view of the exposure apparatus shown in FIG. It is a figure for demonstrating the structure of the scanning unit shown in FIG. It is a figure which shows typically arrangement | positioning of the origin sensor arrange | positioned in the vicinity of the polygon mirror of the scanning unit shown in FIG. It is a figure which shows the structure of the origin sensor shown in FIG. It is a figure which shows the arrangement | positioning relationship between a polygon mirror, an origin sensor, and a sub origin sensor. 6 is a timing chart showing an example of the relationship between the generation timing of an origin signal by an origin sensor and the generation timing of a sub origin signal by a sub origin sensor. It is a functional block diagram for performing drawing modulation of spot light scanned by a scanning unit and rotation control of a polygon mirror of the scanning unit. FIG. 11A is a time chart showing an example of the origin signal, drawing enable signal, and serial data generation state when the origin sensor is not misaligned, and FIG. 11B is the origin sensor misalignment. 6 is a time chart showing an example of a generation state of an origin signal, a drawing enable signal, and serial data in a case where

  A beam scanning apparatus, a beam scanning method, and a pattern drawing apparatus according to an aspect of the present invention will be described in detail below with reference to the accompanying drawings. 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.

  FIG. 1 is a schematic configuration diagram of a device manufacturing system 10 including an exposure apparatus EX that performs an exposure process on a substrate (an object to be irradiated) FS of an 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 −Z direction is the direction in which gravity works.

  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 FS. The device manufacturing system 10 is a manufacturing system in which a manufacturing line for manufacturing electronic devices is constructed. Examples of the electronic device include a flexible display, a film-like touch panel, a film-like color filter for a liquid crystal display panel, flexible wiring, and a flexible sensor. In the present embodiment, a description will be given 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 out a substrate FS from a supply roll (not shown) obtained by winding a flexible sheet-like substrate (sheet substrate) FS in a roll shape, and continuously performs various processes on the delivered substrate FS. After the application, the substrate FS after various treatments is wound up by a collection roll (not shown), and has a so-called roll-to-roll structure. The substrate FS has a strip shape in which the moving direction of the substrate FS is the longitudinal direction (long) and the width direction is the short direction (short). The substrate FS sent from the supply roll is sequentially subjected to various processes by the process apparatus PR1, the exposure apparatus EX, the process apparatus PR2, and the like, and is taken up by the collection roll.

  The X direction is a direction (conveyance direction) from the process apparatus PR1 to the process apparatus PR2 through the exposure apparatus EX in a horizontal plane. The Y direction is a direction orthogonal to the X direction in the horizontal plane, and is the width direction (short direction) of the substrate FS. 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.

  For the substrate FS, 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, those including at least one of them may be used. Further, the thickness and rigidity (Young's modulus) of the substrate FS are within a range that does not cause folds or irreversible wrinkles due to buckling in the substrate FS when passing through the transport path in the device manufacturing system 10. Good. As a base material of the substrate FS, 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 FS may receive heat in each process performed by the process apparatus PR1, the exposure apparatus EX, the process apparatus PR2, and the like, it is possible to select a substrate FS having a material whose thermal expansion coefficient is not significantly large. preferable. 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 FS may be a single layer of ultrathin glass having a thickness of about 100 μm manufactured by a float process or the like, or a laminate in which the above resin film, foil, etc. are bonded to the ultrathin glass. It may be.

  By the way, the flexibility of the substrate FS means a property that the substrate FS can be bent without being sheared or broken even when a force of its own weight is applied to the substrate FS. . 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 FS, the layer structure formed on the substrate FS, the environment such as temperature and humidity, and the like. In any case, when the substrate FS is correctly wound around various conveying rollers, rotating drums, and other members for conveying direction provided in the conveying path in the device manufacturing system 10 according to the present embodiment, the substrate FS buckles and folds. If the substrate FS can be smoothly transported without being damaged or broken (breaking or cracking), it can be said to be a flexible range.

  The process apparatus PR1 performs a pre-process on the substrate FS subjected to the exposure process by the exposure apparatus EX. The process apparatus PR1 performs a pre-process on the substrate FS while transporting the substrate FS sent from the supply roll toward the exposure apparatus EX at a predetermined speed. By this pre-process, the substrate FS sent to the exposure apparatus EX becomes a substrate (photosensitive substrate) having a photosensitive functional layer (photosensitive layer) uniformly or selectively formed on the surface thereof.

  This photosensitive functional layer is applied as a solution on the substrate FS and dried to form a layer (film). A typical photosensitive functional layer is a photoresist (in liquid or dry film form), but as a material that does not require development processing, the photosensitivity of the part that has been irradiated with ultraviolet rays is modified. There is a silane coupling agent (SAM), or a photosensitive reducing agent in which a plating reducing group is exposed on a portion irradiated with ultraviolet rays. When a photosensitive silane coupling agent is used as the photosensitive functional layer, the pattern portion exposed to ultraviolet rays on the substrate FS 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, an electronic device for display A pattern layer (a layer on which a pattern is formed) that becomes a circuit or wiring (for example, a source electrode, a drain electrode, and a gate electrode, a semiconductor, insulation, or a connection wiring that constitute a thin film transistor) can do. When a photosensitive reducing agent is used as the photosensitive functional layer, the plating reducing group is exposed on the pattern portion exposed to the ultraviolet rays on the substrate FS. Therefore, after exposure, the substrate FS 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. However, in the case of assuming an etching process as a subtractive process, the substrate FS sent to the exposure apparatus EX has a base material of PET or the like. PEN may be formed by depositing a metallic thin film such as aluminum (Al) or copper (Cu) on the entire surface or selectively, and further laminating a photoresist layer thereon.

  In the present 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 exposure apparatus (beam scanning apparatus, pattern drawing apparatus). Predetermined representing a circuit or wiring constituting an electronic device for display with respect to the irradiated surface of the substrate FS supplied from the process apparatus PR1 (the surface of the photosensitive functional layer, hereinafter sometimes referred to as a photosensitive surface). The light pattern corresponding to the pattern is irradiated. As will be described in detail later, the exposure apparatus EX transmits the spot light SP of the exposure beam LB on the surface to be irradiated of the substrate FS in a predetermined manner while transporting the substrate FS in the + X direction (sub-scanning direction). While performing one-dimensional scanning (main scanning) in the scanning direction (main scanning direction, Y direction), the intensity of the spot light SP is modulated (on / off) at high speed according to pattern data (drawing data, pattern information). Thereby, a light pattern corresponding to a predetermined pattern such as a circuit or wiring constituting the electronic device is drawn and exposed on the irradiated surface of the substrate FS. That is, the spot light SP is relatively two-dimensionally scanned on the irradiated surface of the substrate FS by the sub-scanning of the substrate FS and the main scanning of the spot light SP, and a predetermined pattern is drawn and exposed on the substrate FS. . Since the substrate FS is transported along the transport direction (+ X direction), the exposure region W where the pattern is exposed by the exposure apparatus EX has a predetermined interval along the long direction (transport direction) of the substrate FS. A plurality will be provided (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 process apparatus PR2 performs a post-process process (for example, application of conductive ink, plating process, development / etching process, etc.) on the substrate FS exposed by the exposure apparatus EX. The process apparatus PR2 performs a post-process on the substrate FS while transporting the substrate FS sent from the exposure apparatus EX toward the collection roll at a predetermined speed. By this subsequent process, a pattern layer of the electronic device is formed on the substrate FS.

  As described above, one pattern layer is generated through at least each process of the device manufacturing system 10. Therefore, in order to generate an electronic device composed of a plurality of pattern layers, each process of the device manufacturing system 10 as shown in FIG. 1 must be performed at least twice. Therefore, a pattern layer can be laminated | stacked by mounting | wearing another device manufacturing system 10 with the collection | recovery roll by which board | substrate FS was wound up as a supply roll. The processed substrate FS is in a state in which a plurality of electronic devices are connected along the longitudinal direction of the substrate FS at a predetermined interval. That is, the substrate FS is a multi-sided substrate.

  The collection roll that collects the substrate FS formed in a state where the electronic devices are connected along the longitudinal direction of the substrate FS may be mounted on a dicing apparatus (not shown). The dicing apparatus to which the collection roll is mounted divides (dices) the processed substrate FS for each electronic device (exposure area W that is a device formation area). Thereby, the electronic device which became the several sheet | seat is formed. In addition, as for the dimension of the board | substrate FS, the dimension of the width direction (direction used as a short length) is about 10 cm-2 m, and the dimension of a length direction (long direction) is 10 m or more, for example. In addition, the dimension of the board | substrate FS is not limited to an above-described dimension.

  Next, the exposure apparatus EX will be described in detail. The exposure apparatus EX has a temperature control chamber ECV. This temperature control chamber ECV suppresses a shape change due to the temperature of the substrate FS transported inside by keeping the inside at a predetermined temperature. The temperature control chamber ECV is arranged on the installation surface E of the manufacturing factory via passive or active vibration isolation units SU1, SU2. The anti-vibration units SU1 and SU2 reduce vibration from the installation surface E. The installation surface E may be the floor surface of the factory itself, or may be a surface on an installation base (pedestal) 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 (pulse light source device) 14, an exposure head 16, a control device 18, and a plurality of alignment microscopes ALGm (m = 1, 2, 3 and 4) and a plurality of encoders ENja and ENjb (j = 1, 2, 3). The control device 18 controls each part of the exposure apparatus EX. The control device 18 includes a computer and a recording medium on which a program is recorded, and the computer functions as the control device 18 of the present embodiment when the computer executes the program.

  The substrate transport mechanism 12 transports the substrate FS transported from the process apparatus PR1 at a predetermined speed in the exposure apparatus EX, and then sends the substrate FS to the process apparatus PR2 at a predetermined speed. The substrate transport mechanism 12 defines a transport path for the substrate FS transported in the exposure apparatus EX. The substrate transport mechanism 12 includes an edge position controller EPC, a drive roller (nip roller) R1, a tension adjustment roller RT1, a rotating drum (cylindrical drum stage) DR, and tension in order from the upstream side (−X direction side) in the transport direction of the substrate FS. An adjustment roller RT2 and drive rollers (nip rollers) R2 and R3 are provided. The substrate FS transferred from the process apparatus PR1 is passed over the rollers in the edge position controller EPC, the drive rollers R1 to R3, the rotary drum DR, and the tension adjustment rollers RT1 and RT2, and is directed to the process apparatus PR2. Are transported.

  The edge position controller EPC adjusts the position in the width direction (the Y direction and the short direction of the substrate FS) of the substrate FS transported from the process apparatus PR1. That is, in the edge position controller EPC, the position at the end (edge) in the width direction of the substrate FS being transported in a state where a predetermined tension is applied is about ± 10 μm to several tens μm with respect to the target position. The position in the width direction of the substrate FS is adjusted so that it falls within the range (allowable range). The edge position controller EPC includes a roller on which the substrate FS is stretched in a state where a predetermined tension is applied, and an edge sensor (end detection unit) (not shown) that detects the position of the edge (edge) in the width direction of the substrate FS. And have. The edge position controller EPC adjusts the position of the substrate FS in the width direction by moving the roller of the edge position controller EPC in the Y direction based on the detection signal detected by the edge sensor. The driving roller R1 rotates while holding both front and back surfaces of the substrate FS conveyed from the edge position controller EPC, and conveys the substrate FS toward the rotating drum DR. The edge position controller EPC moves the roller in the Y direction so that the longitudinal direction of the substrate FS wound around the rotary drum DR is always perpendicular to the central axis AXo of the rotary drum DR, thereby changing the width of the substrate FS. The position in the direction is adjusted appropriately. The edge position controller EPC may appropriately adjust the parallelism between the rotation axis of the roller and the center axis AXo of the edge position controller EPC so as to correct a tilt error in the traveling direction of the substrate FS.

  The rotating drum DR is a cylindrical drum stage having a central axis AXo extending in the Y direction and extending in a direction intersecting with the direction in which gravity acts (Z direction), and a cylindrical outer peripheral surface having a constant radius from the central axis AXo. It is. The rotating drum DR rotates around the central axis AXo while supporting (holding) a part of the substrate FS in a cylindrical shape in the longitudinal direction following this outer peripheral surface (circumferential surface). FS is transported in the + X direction. The rotary drum DR supports an area (part) on the substrate FS on which the beam LB (spot light SP) from the exposure head 16 is projected on the outer peripheral surface thereof. The rotating drum DR supports (closely holds) the substrate FS in the longitudinal direction from the surface (back surface) side opposite to the surface (surface on which the photosensitive surface 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 when a rotational torque from a rotation driving source (not shown) (for example, a motor or a speed reduction mechanism) controlled by the control device 18 is applied. 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 R2 and R3 are arranged at a predetermined interval along the transport direction (+ X direction) of the substrate FS, and give a predetermined slack (play) to the exposed substrate FS. Similarly to the drive roller R1, the drive rollers R2 and R3 rotate while holding both front and back surfaces of the substrate FS, and transport the substrate FS toward the process 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 FS that is wound around and supported by the rotary drum DR. Thereby, the longitudinal tension applied to the substrate FS applied to the rotary drum DR is stabilized within a predetermined range. The control device 18 rotates the drive rollers R1 to R3 by controlling a rotation drive source (not shown) (for example, a motor or a speed reduction mechanism). The rotation axes of the drive rollers R1 to R3 and the rotation axes of the tension adjustment rollers RT1 and RT2 are in principle parallel to the central axis AXo of the rotary drum DR.

  The light source device 14 has a light source (pulse light source) and emits a pulsed beam (pulse beam, pulse light, laser) LB. This beam LB is ultraviolet light having a peak wavelength in a wavelength band of 370 nm or less, and the light emission frequency (oscillation frequency) of the beam (pulse light) LB is Fe. The beam LB emitted from the light source device 14 enters the exposure head 16. The light source device 14 emits and emits the beam LB at the emission frequency Fe under the control of the control device 18. As the light source device 14, a semiconductor laser element that generates pulsed light in the infrared wavelength range, a fiber amplifier that amplifies the pulsed light in the infrared wavelength range, and the amplified pulsed light in the infrared wavelength range is converted into pulsed light in the ultraviolet wavelength range. A fiber amplifier laser light source composed of a wavelength conversion element (harmonic generation element) or the like for conversion into a light source may be used. In that case, high-intensity ultraviolet pulsed light having an oscillation frequency Fe of several hundred MHz and an emission time of one pulse of about picoseconds can be obtained. Although the light source device 14 emits the pulsed beam LB, it may be a light source (CW laser, ultraviolet LED, etc.) that emits a continuously emitting beam.

  The exposure head 16 includes a plurality of scanning units MDn (n = 1, 2,..., 6) on which the beams LB from the light source device 14 are respectively incident. The exposure head 16 scans the spot light SP in the Y direction while irradiating a part of the substrate FS supported by the outer peripheral surface of the rotary drum DR with the plurality of scanning units MDn (MD1 to MD6). To do. Thereby, a predetermined pattern is drawn on the irradiated surface of the substrate FS (on the substrate FS). The exposure head 16 is a so-called multi-beam type exposure head in which a plurality of scanning units MDn (MD1 to MD6) having the same configuration are arranged. Each scanning unit MDn (MD1 to MD6) draws a pattern on the substrate FS using the beam from the light source device 14. Hereinafter, the beam LB from the light source device 14 incident on the scanning unit MDn (MD1 to MD6) may be represented by LBn (LB1 to LB6). Therefore, the beam LBn incident on the scanning unit MD1 is represented by LB1, and similarly, the beam LBn incident on the scanning units MD2 to MD6 is represented by LB2 to LB6.

  As shown in FIG. 2, the plurality of scanning units MDn (MD1 to MD6) are arranged in a predetermined arrangement relationship. The plurality of scanning units MDn (MD1 to MD6) are arranged in a staggered arrangement in two rows in the transport direction (X direction) of the substrate FS across the center plane Poc. The odd-numbered scanning units MD1, MD3, MD5 are arranged on the upstream side (−X direction side) in the transport direction of the substrate FS with respect to the center plane Poc, and 1 with a predetermined interval along the Y direction. Arranged in columns. The even-numbered scanning units MD2, MD4, MD6 are arranged on the downstream side (+ X direction side) in the transport direction of the substrate FS with respect to the center plane Poc, and are arranged in a row at a predetermined interval along the Y direction. Are arranged. The odd-numbered scanning units MD1, MD3, and MD5 and the even-numbered scanning units MD2, MD4, and MD6 are provided symmetrically with respect to the center plane Poc.

  Each scanning unit (scanning module) MDn (MD1 to MD6) projects the projected beam LBn (LB1 to LB6) of the substrate FS while projecting the beam LBn (LB1 to LB6) from the light source device 14 toward the substrate FS. It converges on the spot light SP on the irradiated surface. Each scanning unit MDn (MD1 to MD6) scans the spot light SP converged on the substrate FS in one dimension (Y direction) by the rotating polygon mirror PM (see FIG. 5). The spot light SP of the beam LBn (LB1 to LB6) is scanned one-dimensionally in the main scanning direction (Y direction) on the irradiated surface of the substrate FS by the rotated polygon mirror PM of each scanning unit MDn (MD1 to MD6). Linear drawing lines (scanning lines) SLn (SL1 to SL6) on which a pattern for one line is drawn are defined on the irradiated surface of the substrate FS. The drawing lines SLn (SL1 to SL6) indicate the scanning trajectory of the spot light SP of the beam LBn (LB1 to LB6) irradiated on the substrate FS. The configuration of the scanning unit MDn will be described in detail later.

  The scanning unit MD1 scans the spot light SP of the beam LB1 in the main scanning direction (Y direction) along the drawing line SL1, and similarly, the scanning units MD2 to MD6 scan the spot light SP of the beams LB2 to LB6. Scan in the main scanning direction (Y direction) along SL2 to SL6. The drawing lines (scanning lines) SLn (SL1 to SL6) of the plurality of scanning units MDn (MD1 to MD6) are related to the Y direction (the width direction of the substrate FS, the scanning direction) as shown in FIGS. They are set to be joined together without being separated from each other. The beams LBn (LB1 to LB6) incident on the scanning units MDn (MD1 to MD6) are linearly polarized light (P-polarized light or S-polarized light) polarized in a predetermined direction. In the present embodiment, P-polarized light is used. The beam is incident.

  As shown in FIGS. 2 and 3, each scanning unit MDn (MD1 to MD6) covers the scanning area so that all of the plurality of scanning units MDn (MD1 to MD6) cover all of the width direction of the exposure area W. Sharing. Thereby, each scanning unit MDn (MD1-MD6) can draw a pattern for every some area | region divided | segmented in the width direction of the board | substrate FS. For example, when the scanning width in the Y direction (the length of the drawing line SLn) by one scanning unit MDn is about 20 to 60 mm, three odd numbered scanning units MD1, MD3, MD5 and even numbered scanning unit MD2 are used. , MD4 and MD6, a total of six scanning units MDn, are arranged in the Y direction, so that the width in the Y direction that can be drawn is increased to about 120 to 360 mm. In principle, the lengths (scanning lengths) of the respective drawing lines SLn (SL1 to SL6) are the same. That is, when the drawing magnification is the initial value (no magnification correction), the scanning distances of the spot lights SP of the beams LB1 to LB6 scanned along the drawing lines SL1 to SL6 are the same. Note that the width of the exposure region W can be increased by increasing the length of the drawing line SLn itself or increasing the number of scanning units MDn arranged in the Y direction.

  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 The length is set to about 31 mm with a margin of about 0.5 mm on each of the scanning start point (drawing start point) side and the scanning end point (drawing end point) side of the drawing line SLn. By setting in this way, within the range of the maximum scanning length of 31 mm of the spot light SP, the position of the 30 mm drawing line SLn is shifted (finely adjusted) in the main scanning direction, or the drawing magnification is finely adjusted. Is possible. The maximum scanning length of the spot light SP is not limited to 31 mm, and is determined mainly by the aperture and position of the fθ lens FT (see FIG. 5) provided after the polygon mirror PM in the scanning unit MDn.

  The plurality of drawing lines SLn (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, SL5 are positioned on the irradiated surface on the upstream side (−X direction side) in the transport direction of the substrate FS wound around the rotary drum DR with respect to the center plane Poc. The even-numbered drawing lines SL2, SL4, and SL6 are positioned on the irradiated surface on the downstream side (+ X direction side) in the transport direction of the substrate FS wound around the rotary drum DR with respect to the center plane Poc. The drawing lines SL1 to SL6 are substantially parallel along the width direction (Y direction) of the substrate FS, that is, along the central axis AXo of the rotary drum DR.

  The drawing lines SL1, SL3, and SL5 are arranged in a line on a straight line at a predetermined interval along the width direction (scanning direction) of the substrate FS. Similarly, the drawing lines SL2, SL4, and SL6 are arranged in a line on a straight line at a predetermined interval along the width direction (scanning direction) of the substrate FS. 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 FS. Similarly, the drawing line SL3 is arranged between the drawing line SL2 and the drawing line SL4 in the width direction of the substrate FS. The drawing line SL4 is arranged between the drawing line SL3 and the drawing line SL5 in the width direction of the substrate FS, and the drawing line SL5 is arranged between the drawing line SL4 and the drawing line SL6 in the width direction of the substrate FS. Is done.

  The scanning direction of the spot light SP of the beams LB1, LB3, and LB5 scanned along each of the odd-numbered drawing lines SL1, SL3, and SL5 is a one-dimensional direction and is the −Y direction. The scanning direction of the spot light SP of the beams LB2, LB4, and LB6 scanned along the even-numbered drawing lines SL2, SL4, and SL6 is a one-dimensional direction and is a + Y direction. Therefore, the scanning direction of the spot light SP scanned along the drawing lines SL1, SL3, SL5 and the scanning direction of the spot light SP scanned along the drawing lines SL2, SL4, SL6 are opposite to each other. Yes. Thereby, the end on the drawing start point side of the pattern drawn on each of the drawing lines SL1, SL3, and SL5, and the end on the drawing start point side of the pattern drawn on each of the drawing lines SL2, SL4, and SL6 Are closely adjacent to each other in the Y direction, or overlapped with a predetermined length (for example, the dimension of the spot light SP, or several μm to several tens μm). Also, the end on the drawing end point side of the pattern drawn on each of the drawing lines SL3 and SL5 and the end on the drawing end point side of the pattern drawn on each of the drawing lines SL2 and SL4 are mutually in relation to the Y direction. Exactly adjacent or overlap with a predetermined length. Note that the length (predetermined length) at which the end portions of the patterns drawn by the drawing lines SLn adjacent in the Y direction partially overlap each other is, for example, drawn with respect to the length of each drawing line SLn. It may be a range of several percent or less in the Y direction including the start point or the drawing end point. Thus, joining the drawing lines SLn in the Y direction means that the ends of the patterns drawn by the drawing lines SLn are adjacent or partially overlapped (predetermined length).

The width (dimension in the X direction) of the drawing line SLn in the sub-scanning direction is a thickness corresponding to the size (diameter) φ of the spot light SP. For example, when the size φ of the spot light SP is 3 μm, the width of each drawing line SLn in the sub-scanning direction is also 3 μm. The spot light SP may be irradiated along the drawing line SLn so as to overlap by a predetermined length (for example, half the size φ of the spot light SP). Further, when drawing lines SLn (for example, the drawing line SL1 and the drawing line SL2) adjacent in the Y direction are connected to each other, they are overlapped by a predetermined length (for example, half the size φ of the spot light SP). Good. Note that the effective size φ of the spot light SP is determined by 1 / e ² (or full width at half maximum) 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 case of the present embodiment, since the beam LB (LBn) from the light source device 14 is pulsed light, the spot light SP projected on the drawing line SLn during the main scanning is the oscillation frequency of the beam LB (LBn). It becomes discrete according to Fe. Therefore, it is necessary to overlap the spot light SP projected by one pulse light of the beam LB (LBn) 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 Vs of the spot light SP, and the oscillation frequency Fe of the beam LB (LBn), but in this embodiment, it is about φ / 2. Therefore, also in the sub-scanning direction (direction perpendicular to the drawing line SLn), the substrate FS effectively applies the spot light SP between one scanning of the spot light SP along the drawing line SLn and the next scanning. It is desirable to set so as to move by a distance of about half or less of a large size φ. Further, the exposure amount to the photosensitive functional layer on the substrate FS can be set by adjusting the peak value of the beam LB (LBn). However, the exposure amount can be set in a situation where the intensity of the beam LB (LBn) cannot be increased. When it is desired to increase, it is caused by any one of a decrease in the scanning speed Vs of the spot light SP in the main scanning direction, an increase in the oscillation frequency Fe of the beam LB (LBn), or a decrease in the transport speed Vt of the substrate FS in the sub-scanning direction. The overlap amount of the spot light SP in the main scanning direction or sub-scanning direction may be increased to ½ or more of the effective size φ. The scanning speed Vs of the spot light SP in the main scanning direction increases in proportion to the rotational speed (rotational speed Vp) of the polygon mirror PM.

  Each scanning unit MDn (MD1 to MD6) applies the beam LBn (LB1 to LB6) to the substrate FS so that the beam LBn (LB1 to LB6) is perpendicular to the irradiated surface of the substrate FS at least in the XZ plane. Irradiate toward. That is, each scanning unit MDn (MD1 to MD6) travels toward the central axis AXo of the rotary drum DR on the XZ plane, that is, so as to be parallel to the normal line of the irradiated surface. To LB6) are irradiated (projected) onto the substrate FS. Each scanning unit MDn (MD1 to MD6) has a beam LBn (LB1 to LB6) that irradiates the drawing line SLn (SL1 to SL6) with respect to the surface to be irradiated of the substrate FS in a plane parallel to the YZ plane. The beams LBn (LB1 to LB6) are irradiated toward the substrate FS so as to be vertical. That is, the beam LBn (LB1 to LB6) projected onto the substrate FS 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 FS through a specific point (for example, a middle point) of a predetermined drawing line SLn (SL1 to SL6) defined by each scanning unit MDn (MD1 to MD6) (or The optical axis) is also referred to as the irradiation center axis Len (Le1 to Le6) (see FIG. 2). Therefore, the beam LBn projected from each scanning unit MDn onto the irradiated surface of the substrate FS so as to pass a specific point on the drawing line SLn is coaxial with the irradiation center axis Len.

  Each irradiation central axis Len (Le1 to Le6) is a line connecting the drawing line SLn (SL1 to SL6) and the central axis AXo on the XZ plane. The irradiation center axes Le1, Le3, Le5 of the odd-numbered scanning units MD1, MD3, MD5 are in the same direction on the XZ plane. The irradiation center axes Le2, Le4, Le6 of the odd-numbered scanning units MD2, MD4, MD6 are in the same direction on the XZ plane. In the XZ plane, the irradiation center axes Le1, Le3, Le5 and the irradiation center axes Le2, Le4, Le6 are set so that the angle with respect to the center plane Poc becomes ± θ1 (FIG. 1, FIG. 2).

  As shown in FIG. 3, the alignment microscope ALGm (ALG1 to ALG4) shown in FIG. 1 has positional information (m = 1, 2, 3, 4) on a plurality of alignment marks MKm (m = 1, 2, 3, 4) formed on the substrate FS. Mark position information) and is provided along the Y direction. The marks MKm (MK1 to MK4) are reference marks for relatively aligning (aligning) the predetermined pattern drawn in the exposure region W on the irradiated surface of the substrate FS and the substrate FS. The plurality of alignment microscopes ALGm (ALG1 to ALG4) detect the mark MKm (MK1) in order to detect the position information of the plurality of marks MKm (MK1 to MK4) on the substrate FS supported by the circumferential surface of the rotary drum DR. To MK4). The alignment microscope ALGm (ALG1 to ALG4) is provided on the upstream side (−X direction side) in the transport direction of the substrate FS with respect to the irradiated region (drawing lines SL1 to SL6) of the spot light SP on the substrate FS by the exposure head 16. It has been.

  The alignment microscope ALGm (ALG1 to ALG4) is a magnified image of the observation region Vwm (Vw1 to Vw4) including the light source that projects the illumination light for alignment onto the substrate FS and the mark MKm (MK1 to MK4) on the surface of the substrate FS. An observation optical system (including an objective lens) to be obtained, and an image sensor such as a CCD or CMOS that captures an enlarged image of the observation optical system with a high-speed shutter while the substrate FS is moving in the transport direction. Imaging signals captured by the alignment microscopes ALGm (ALG1 to ALG4) are sent to the control device 18. The control device 18 performs the mark MKm (MK1) on the substrate FS based on the image analysis of the imaging signal and the information on the rotational position of the rotating drum DR at the moment of imaging (information measured by encoders EN1a and EN1b described later). ˜MK4) position information is detected. Note that the illumination light for alignment is light in a wavelength region that has little sensitivity to the photosensitive functional layer on the substrate FS, for example, light having a wavelength of about 500 to 800 nm.

  A plurality of marks MKm (MK1 to MK4) are provided around each exposure region W. A plurality of marks MK1 and MK4 are formed on both sides of the exposure region W in the width direction of the substrate FS at a constant interval Dh along the longitudinal direction of the substrate FS. The mark MK1 is formed on the −Y direction side in the width direction of the substrate FS, and the mark MK4 is formed on the + Y direction side in the width direction of the substrate FS. Such marks MK1 and MK4 are arranged so as to be at the same position in the longitudinal direction (X direction) of the substrate FS when the substrate FS is not deformed due to a large tension or a thermal process. Is done. Further, the marks MK2 and MK3 are formed between the mark MK1 and the mark MK4 and in the margin part between the + X direction side and the −X direction side of the exposure region W along the width direction (short direction) of the substrate FS. ing. The mark MK2 is formed on the −Y direction side in the width direction of the substrate FS, and the mark MK3 is formed on the + Y direction side of the substrate FS. Further, the distance in the Y direction between the mark MK1 and the margin mark MK2 arranged at the −Y direction end of the substrate FS, the distance in the Y direction between the margin mark MK2 and the mark MK3, and the substrate FS. The interval in the Y direction between the mark MK4 arranged at the end on the + Y direction side and the mark MK3 in the margin is set to the same distance. These marks MKm (MK1 to MK4) may be formed together when the pattern layer of the first layer is formed. For example, when the pattern of the first layer is exposed, the pattern for the mark MKm may be exposed around the exposure area W where the pattern is exposed. The 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. In addition, 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.

  FIG. 3 shows an arrangement of a plurality of marks MKm (MK1 to MK4) when the exposure region W is not deformed. Therefore, when the substrate FS is deformed due to a large tension or is affected by a thermal process, and the exposure region W is deformed (distorted), the plurality of marks MKm (MK1 to MK4) are arranged with respect to the substrate FS. Will also be deformed (distorted).

  The plurality of alignment microscopes ALG1 to ALG4 are provided in order of ALG1 to ALG4 from the −Y direction side of the substrate FS corresponding to the positions of the plurality of marks MK1 to MK4. Specifically, the alignment microscope ALG1 is arranged so that the mark MK1 is positioned in the observation region (detection region) Vw1 by the objective lens with respect to the width direction of the substrate FS (with respect to the Y direction). Similarly, the alignment microscopes ALG2 to ALG4 are arranged such that the marks MK2 to MK4 are located in the observation direction Vw2 to Vw4 by the objective lens in the width direction (with respect to the Y direction) of the substrate FS. In the plurality of alignment microscopes ALGm (ALG1 to ALG4), the distance between the exposure position (drawing lines SL1 to SL6) and the observation region Vwm (Vw1 to Vw4) of the alignment microscope ALGm (ALG1 to ALG4) is the exposure region in the X direction. It is provided to be shorter than the length of W in the X direction. The number of alignment microscopes ALGm provided in the Y direction can be changed according to the number of marks MKm formed in the width direction of the substrate FS. The size of the observation region Vwm on the surface to be irradiated of the substrate FS is set according to the size of the mark MKm and the alignment accuracy (position measurement accuracy), but is about 100 to 500 μm square.

  As shown in FIGS. 1 and 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. Yes. The scale portions SDa and SDb are diffraction gratings in which concave or convex grating lines are engraved at a constant pitch (for example, 20 μm) in the circumferential direction of the outer peripheral surface of the rotary drum DR, and are configured as incremental scales. . The scale portions SDa and SDb rotate integrally with the rotary drum DR around the central axis AXo. A plurality of encoder heads (scale reading heads) ENja (EN1a to EN3a) and ENjb (EN1b to EN3b) are provided so as to face the scale portions SDa and SDb. These encoder heads (hereinafter also simply referred to as encoders) ENja and ENjb optically detect the rotational position of the rotary drum DR. Three encoders ENja (EN1a to EN3a) are provided to face the scale portion SDa provided at the −Y direction end of the rotating drum DR, and provided at the + Y direction end of the rotating drum DR. Three encoders ENjb (EN1b to EN3b) are provided facing the scale part SDb. The encoders EN1a and EN1b are arranged at the same position with respect to the rotation direction (X direction) of the rotary drum DR. Similarly, the encoders EN2a and EN2b and the encoders EN3a and EN3b are also arranged at the same position with respect to the rotation direction (X direction) of the rotary drum DR.

  The encoders ENja and ENjb project a measurement light beam toward the scale portions SDa and SDb, and photoelectrically detect the reflected light beam (diffracted light), thereby detecting the circumference of the scales (diffraction gratings) of the scale portions SDa and SDb. A detection signal (a two-phase signal of a sine wave and a cosine wave) corresponding to the change in position in the direction is output to the control device 18. The control device 18 digitizes the detection signal by an interpolation processing circuit (not shown) and a digital counter circuit, so that the rotation angle position and angle change of the rotary drum DR or the movement amount of the substrate FS can be submicron resolution. It can be measured. This counter circuit individually counts the detection signals of the encoders ENja (EN1a to EN3a) and ENjb (EN1b to EN3b). The control device 18 can also measure the transport speed of the substrate FS from the angle change of the rotary drum DR. The counter circuit corresponding to each of the encoders ENja (EN1a to EN3a) and ENjb (EN1b to EN3b) has one circumferential direction of the scale portions SDa and SDb by the encoders ENja (EN1a to EN3a) and ENjb (EN1b to EN3b). When the origin mark (origin pattern) ZZ (see FIG. 2) formed at the location is detected, the count value of the counter circuit corresponding to the encoders ENja and ENjb that detected the origin mark ZZ is reset to zero.

  The encoders EN1a and EN1b are arranged on the installation direction line Lx1 with respect to the XZ plane. The installation azimuth line Lx1 is a line connecting the projection positions (reading positions) of the measurement light beams of the encoders EN1a and EN1b to the scale portions SDa and SDb and the central axis AXo with respect to the XZ plane. Therefore, the count value based on the detection signals detected by the encoders EN1a and EN1b represents the rotational angle position of the rotary drum DR viewed from the installation direction line Lx1. Further, the installation orientation line Lx1 is a line connecting the observation region Vwm (Vw1 to Vw4) of each alignment microscope ALGm (ALG1 to ALG4) and the central axis AXo on the XZ plane. That is, each alignment microscope ALGm (ALG1 to ALG4) is arranged on the installation direction line Lx1 in the XZ plane.

  The encoders EN2a and EN2b are provided on the upstream side (−X direction side) in the transport direction of the substrate FS with respect to the center plane Poc, and further downstream (+ X direction) in the transport direction of the substrate FS from the encoders EN1a and EN1b. Side). The encoders EN2a and EN2b are arranged on the installation direction line Lx2 with respect to the XZ plane. The installation azimuth line Lx2 is a line connecting the projection positions (reading positions) of the measurement light beams on the scale portions SDa and SDb of the encoders EN2a and EN2b and the central axis AXo with respect to the XZ plane. Therefore, the count value based on the detection signals detected by the encoders EN2a and EN2b represents the rotational angle position of the rotary drum DR as viewed from the installation direction line Lx2. The installation azimuth line Lx2 overlaps with the irradiation center axes Le1, Le3, and Le5 at the same angular position with respect to the XZ plane.

  The encoders EN3a and EN3b are provided on the downstream side (+ X direction side) in the transport direction of the substrate FS with respect to the center plane Poc. The encoders EN3a and EN3b are arranged on the installation direction line Lx3 with respect to the XZ plane. 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 with respect to the XZ plane. Therefore, the count value based on the detection signals detected by the encoders EN3a and EN3b represents the rotational angle position of the rotary drum DR viewed from the installation direction line Lx3. The installation azimuth line Lx3 overlaps with the irradiation center axes Le2, Le4, and Le6 at the same angular position with respect to the XZ plane. 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 FIGS. 1 and 2).

  Incidentally, the substrate FS is wound inside the scale portions SDa and SDb at both ends of the rotary drum DR. In FIG. 1, the radius from the central axis AXo of the outer peripheral surface of the scale portions SDa and SDb is set smaller than the radius from the central axis AXo of the outer peripheral surface of the rotary drum DR. However, as shown in FIG. 2, the outer peripheral surfaces of the scale portions SDa and SDb may be set so as to be flush with the outer peripheral surface of the substrate FS wound around the rotary drum DR. That is, the radius (distance) from the central axis AXo of the outer peripheral surfaces of the scale parts SDa and SDb and the radius (distance) from the central axis AXo of the outer peripheral surface (irradiated surface) of the substrate FS wound around the rotary drum DR May be set to be the same. Accordingly, each encoder ENja (EN1a to EN3a) and ENjb (EN1b to EN3b) can detect the scale portions SDa and SDb at the same radial position as the irradiated surface of the substrate FS wound around the rotary drum DR. . Therefore, Abbe error caused by the difference between the measurement positions by the encoders ENja and ENjb and the processing positions (drawing lines SL1 to SL6) in the radial direction of the rotary drum DR can be reduced.

  However, since the thickness of the substrate FS as the irradiated body is greatly different from ten to several hundred μm, the radius of the outer peripheral surface of the scale portions SDa and SDb and the outer peripheral surface of the substrate FS wound around the rotary drum DR It is difficult to always make the radius the same. Therefore, in the case of the scale portions SDa and SDb shown in FIG. 2, the radius of the outer peripheral surface (scale surface) is set to coincide with the radius of the outer peripheral surface of the rotary drum DR. Furthermore, the scale portions SDa and SDb can be formed of individual disks, and the disks (scale disks) can be coaxially attached to the shaft Sft of the rotary drum DR. Even in this case, it is preferable to align the radius of the outer peripheral surface (scale surface) of the scale disk and the radius of the outer peripheral surface of the rotary drum DR so that the Abbe error falls within the allowable value.

  When the rotation angle position of the rotary drum DR in each installation azimuth line Lx1, Lx2, Lx3 with respect to the origin mark ZZ attached at one place in the rotating direction of the rotary drum DR is the same, the counter circuit corresponding to the encoders EN1a, EN1b The count value, the count value of the counter circuit corresponding to the encoders EN2a and EN2b, and the count value of the counter circuit corresponding to the encoders EN3a and EN3b are the same. Therefore, the control device 18 uses a plurality of scanning units MDn (MD1 to MD6) based on the count value based on the encoders EN1a and EN1b, the count value based on the encoders EN2a and EN2b, and the count value based on the encoders EN3a and EN3b. The scanning start timing of the spot light SP can be controlled.

  Specifically, the control device 18 determines the substrate FS based on the position information of the marks MKm (MK1 to MK4) on the substrate FS detected using the plurality of alignment microscopes ALGm (ALG1 to ALG4) and the encoders EN1a and EN1b. The drawing exposure start position of the exposure region W in the longitudinal direction (X direction) is determined. The count value based on the encoders EN1a and EN1b at that time is set to 100, for example. In this case, when the count value based on the encoders EN2a and EN2b reaches 100, the drawing exposure start position of the exposure region W in the longitudinal direction of the substrate FS is positioned on the drawing lines SL1, SL3, and SL5. Therefore, when the count value based on the encoders EN2a and EN2b reaches 100, the control device 18 starts scanning the spot light SP by the scanning units MD1, MD3, and MD5. When the count value based on the encoders EN3a and EN3b reaches 100, the drawing exposure start position of the exposure region W in the longitudinal direction of the substrate FS is positioned on the drawing lines SL2, SL4, and SL6. Therefore, when the count value based on the encoders EN3a and EN3b reaches 100, the control device 18 starts scanning the spot light SP by the scanning units MD2, MD4, and MD6.

  The count value (count value) based on the encoders EN1a and EN1b is one of the count values counted by the counter circuit based on the detection signals detected by the encoders EN1a and EN1b, or the average value of the two count values. Means. Similarly, the count value (count value) based on the encoders EN2a and EN2b is one of the count values counted by the counter circuit based on the detection signals detected by the encoders EN2a and EN2b, or the average of the two count values. The count value (count value) based on the encoders EN3a and EN3b means one of the count values counted by the counter circuit based on the detection signal detected by the encoders EN3a and EN3b, or two count values Mean value of Except when the rotating drum DR rotates eccentrically with respect to the central axis AXo due to a manufacturing error of the rotating drum DR or the like, in principle, a count value counted based on the detection signal detected by the encoder EN1a, This is the same as the count value counted based on the detection signal detected by the encoder EN1b. The same applies to the encoders EN2a and EN2b and the encoders EN3a and EN3b.

  FIG. 4 is an enlarged view of a main part of the exposure apparatus EX. The exposure apparatus EX further includes a plurality of light introducing optical systems BDUn (n = 1, 2,..., 6) and a main body frame UB. The plurality of light introducing optical systems BDUn (BDU1 to BDU6) guide the beam LB (LBn) from the light source device 14 to the plurality of scanning units MDn (MD1 to MD6). The light introducing optical system BDU1 guides the beam LB1 to the scanning unit MD1, and similarly, the light introducing optical systems BDU2 to BDU6 guide the beams LB2 to LB6 to the scanning units MD2 to MD6. Each light introducing optical system BDUn (BDU1 to BDU6) corresponds to the beam LBn (LB1 to LB6) so that the optical axis of the beam LBn (LB1 to LB6) is coaxial with the irradiation center axis Len (Le1 to Le6). It injects into scanning unit MDn (MD1-MD6). That is, the beam LB1 incident on the scanning unit MD1 from the light introducing optical system BDU1 is coaxial with the irradiation center axis Le1. Similarly, beams LB2 to LB6 incident on the scanning units MD2 to MD6 from the light introducing optical systems BDU2 to BDU6 are coaxial with the irradiation center axes Le2 to Le6. The beam LB from the light source device 14 is branched into each light introducing optical system BDUn (BDU1 to BDU6) by an optical member such as a beam splitter or a switching optical deflector (for example, an acoustooptic modulator). Or selectively incident.

  The plurality of light introducing optical systems BDUn (BDU1 to BDU6) have a plurality of drawing optical elements AOMn (n = 1, 2,..., 6). The plurality of drawing optical elements AOMn (AOM1 to AOM6) modulate (on / off) the intensity of the beams LBn (LB1 to LB6) guided to the plurality of scanning units MDn (MD1 to MD6) at high speed according to the pattern data. . The light introducing optical system BDU1 has a drawing optical element AOM1, and similarly, the light introducing optical systems BDU2 to BDU6 have drawing optical elements AOM2 to AOM6. The drawing optical element AOMn is an acousto-optic modulator having transparency to the beam LB. The drawing optical element AOMn uses an ultrasonic signal (high frequency signal) to diffract the incident beam LB from the light source device 14 at a diffraction angle corresponding to the frequency of the high frequency, and thus travels the optical path of the beam LB, that is, travels. Change direction. The drawing optical elements AOMn (AOM1 to AOM6) turn on / off generation of the first-order diffracted light (beam LBn) obtained by diffracting the incident beam LB in accordance with on / off of the drive signal which is a high-frequency signal from the control device 18. Turn off.

  The drawing optical element AOMn (AOM1 to AOM6) allows the incident light beam LB from the light source device 14 to pass through without being diffracted when the drive signal (high-frequency signal) from the control device 18 is off. The beam LB is guided to an absorber (not shown) provided in the light introducing optical system BDUn (BDU1 to BDU6). This absorber is an optical trap that absorbs the beam LB for suppressing leakage of the beam LB to the outside. Therefore, when the drive signal is OFF, the beam (0th order light, 0th order beam) LB transmitted through the drawing optical element AOMn (AOM1 to AOM6) does not enter the scanning unit MDn (MD1 to MD6). That is, the intensity of the beam LBn (LB1 to LB6) passing through the scanning unit MDn (MD1 to MD6) is low (zero). This means that when viewed on the irradiated surface of the substrate FS, the intensity of the spot light SP of the beam LBn (LB1 to LB6) irradiated on the irradiated surface is modulated to a low level (zero). To do.

  On the other hand, the drawing optical element AOMn (AOM1 to AOM6) generates the first-order diffracted light diffracted from the incident beam LB when the drive signal (high-frequency signal) from the control device 18 is on. The beams LBn (LB1 to LB6) which are the folding lights are guided to the scanning units MDn (MD1 to MD6). Therefore, when the drive signal is on, the intensity of the beam LBn (LB1 to LB6) passing through the scanning unit MDn (MD1 to MD6) is high. This means that when viewed on the irradiated surface of the substrate FS, the intensity of the spot light SP of the beam LBn (LB1 to LB6) irradiated on the irradiated surface is modulated to a high level. Thus, the drawing optical elements AOMn (AOM1 to AOM6) can be switched on / off by applying the on / off drive signal to the drawing optical elements AOMn (AOM1 to AOM6).

  The control device 18 turns on the drive signal (high-frequency signal) applied to each drawing optical element AOMn (AOM1 to AOM6) based on the pattern data corresponding to the pattern drawn by each scanning unit MDn (MD1 to MD6). / Turn off. The pattern data is provided for each scanning unit MDn (MD1 to MD6). The pattern data is stored in a memory (not shown).

  Here, the pattern data will be briefly described. The pattern data is obtained by dividing a pattern drawn by each scanning unit MDn by pixels having a dimension Pxy set in accordance with the size φ of the spot light SP, and a plurality of pixels. Each is represented by logical information (pixel data) corresponding to the pattern. That is, in the pattern 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 FS is the column direction. Thus, the bitmap data is composed of logical information of a plurality of pixels that are two-dimensionally decomposed. The logical information of this pixel is 1-bit data of “0” or “1”. The logical information “0” means that the intensity of the spot light SP irradiated on the substrate FS is lowered, and the logical information “1” indicates that the intensity of the spot light SP irradiated on the substrate FS is high. Means level. Therefore, when the logical information of the pixel is “0”, the control device 18 turns off the drive signal (high frequency signal) applied to the drawing optical element AOMn, and when the logical information of the pixel is “1”. Then, the drive signal (high frequency signal) applied to the drawing optical element AOMn is turned on.

  The pixels for one column of the pattern data correspond to one drawing line SLn, and the intensity of the spot light SP projected onto the irradiated surface of the substrate FS along one drawing line SLn is Modulation is performed according to the logical information of the pixels for one column. That is, the drawing line SLn is a scanning line in which the spot light SP is scanned with its intensity modulated by the logical information of the pixels for one column, that is, drawn. This logical information of the pixels for one column is called serial data DLn. That is, the pattern data is bitmap data in which a plurality of serial data DLn such as serial data DLn in the first column, serial data DLn in the second column,. The serial data DLn of the scanning unit MD1 is DL1, and similarly, the serial data DLn of the scanning units MD2 to MD6 is DL2 to DL6. Spots along the drawing lines SLn (SL1 to SL6) by the respective scanning units MDn (MD1 to MD6) by starting driving the drawing optical elements AOMn (AOM1 to AOM6) based on the serial data DLn (DL1 to DL6) Scanning of the light SP is started. That is, during the period in which the drawing optical elements AOMn (AOM1 to AOM6) are driven based on the serial data DLn (DL1 to DL6), the drawing lines SLn (SL1 to SL6) by the scanning units MDn (MD1 to MD6) are driven. Scanning of the spot light SP along is performed.

  Note that the number of pixels for one column (the number of pixels of the serial data DLn) is determined according to the size of the pixel on the irradiated surface and the length of the drawing line SLn, and the size of one pixel is the spot light SP. It depends on the size φ. As described above, when the spot light SP continuously irradiated on the irradiated surface is overlapped by about ½ of the size φ, the size of one pixel is approximately the same as the size φ of the spot light SP, or More than that. When the effective size φ of the spot light SP is 3 μm, the size of one pixel is set to about 3 μm square or more. For example, when the size of one pixel is 3 μm square and the spot light SP having a diameter size φ of 3 μm is overlapped by about ½ of the size φ, the two spot lights SP correspond to one pixel. Therefore, the number of pixels for one column of the pattern data is ½ times the number (number of pulses) of the spot light SP projected along the drawing line SLn. In order to draw a finer pattern, the effective size φ of the spot light SP can be made smaller and the size of one pixel can be set smaller.

  The main body frame UB holds a plurality of light introducing optical systems BDUn (BDU1 to BDU6) and a plurality of scanning units MDn (MD1 to MD6). The main body frame UB includes a first frame Ub1 that holds a plurality of light introduction optical systems BDUn (BDU1 to BDU6), and a second frame Ub2 that holds a plurality of scanning units MDn (MD1 to MD6). The first frame Ub1 holds a plurality of light introducing optical systems BDUn (BDU1 to BDU6) on the upper side (+ Z direction) of the plurality of scanning units MDn (MD1 to MD6) held by the second frame Ub2. The first frame Ub1 supports the plurality of light introducing optical systems BDUn (BDU1 to BDU6) from the lower side (−Z direction). The odd-numbered light introducing optical systems BDU1, BDU3, and BDU5 are supported by the first frame Ub1 at the positions corresponding to the positions of the odd-numbered scanning units MD1, MD3, and MD5. That is, the odd-numbered light introducing optical systems BDU1, BDU3, and BDU5 are 1 at a predetermined interval along the Y direction on the upstream side (−X direction side) in the transport direction of the substrate FS with respect to the center plane Poc. Arranged in a row. The even-numbered light introducing optical systems BDU2, BDU4, and BDU6 are supported by the first frame Ub1 at the arrangement positions corresponding to the positions of the even-numbered scanning units MD2, MD4, and MD6. That is, the even-numbered light introducing optical systems BDU2, BDU4, and BDU6 are arranged in a row at a predetermined interval along the Y direction on the downstream side (+ X direction side) in the transport direction of the substrate FS with respect to the center plane Poc. Placed in.

  The first frame Ub1 is provided with a plurality of openings Hsn (Hs1 to Hs6) corresponding to the plurality of light introducing optical systems BDUn (BDU1 to BDU6). By the plurality of openings Hsn (Hs1 to Hs6), the beams LBn (LB1 to LB6) emitted from the plurality of light introducing optical systems BDUn (BDU1 to BDU6) are not blocked by the first frame Ub1 and corresponding scanning is performed. Incident on the unit MDn (MD1 to MD6). That is, the beams LBn (LB1 to LB6) emitted from the light introducing optical system BDUn (BDU1 to BDU6) enter the corresponding scanning units MDn (MD1 to MD6) through the openings Hsn (Hs1 to Hs6). . The first frame Ub1 may support a plurality of light introducing optical systems BDUn (BDU1 to BDU6) from the upper side (+ Z direction) side or from the side (X direction) side.

  The second frame Ub2 includes a plurality of scanning units MDn (MD1 to MD6) so that each of the plurality of scanning units MDn (MD1 to MD6) can rotate (rotate) around the irradiation center axis Len (Le1 to Le6). Holds pivotally. Even when the scanning units MDn (MD1 to MD6) are rotated by rotating the scanning units MDn (MD1 to MD6) around the irradiation center axis Len (Le1 to Le6), the scanning units MDn (MD1) The positional relationship between the beam LBn (LB1 to LB6) incident on MD6) and the optical members in the scanning unit MDn (MD1 to MD6) does not change. Accordingly, even when each scanning unit MDn (MD1 to MD6) rotates, each scanning unit MDn (MD1 to MD6) projects the spot light SP of the beam LBn (LB1 to LB6) onto the substrate FS. The spot light SP can be scanned along the defined drawing lines SLn (SL1 to SL6). By the rotation of each scanning unit MDn (MD1 to MD6), each drawing line SLn (SL1 to SL6) rotates around the irradiation center axis Len (Le1 to Le6) on the irradiated surface of the substrate FS. Thereby, each drawing line SLn (SL1 to SL6) is inclined from a state parallel to the Y axis (center axis AXo). The rotation of each scanning unit MDn (MD1 to MD6) around the irradiation center axis Len is performed by an actuator (not shown) under the control of the control device 18.

  Even if the irradiation center axis Len of the scanning unit MDn and the axis (rotation center axis) where the scanning unit MDn actually rotates do not completely coincide, they may be coaxial within a predetermined allowable range. The predetermined allowable range includes, for example, the drawing start point (or drawing end point) of the actual drawing line SLn when the scanning unit MDn is rotated by a predetermined angle θsm, the irradiation center axis Len, and the rotation center axis. When the scanning unit MDn is rotated by a predetermined angle θsm, the amount of difference from the drawing start point (or drawing end point) of the design drawing line SLn when the scanning unit MDn is rotated by a predetermined angle θsm is the spot light SP. The main scanning direction is set to be within a predetermined distance (for example, the diameter of the size φ of the spot light SP). Further, even if the optical axis of the beam LBn actually incident on the scanning unit MDn does not completely coincide with the rotation center axis of the scanning unit MDn, it may be coaxial within the above-described predetermined allowable range.

  FIG. 5 is a diagram for explaining the configuration of the scanning unit MDn. Since each scanning unit MDn (MD1 to MD6) has the same configuration, the scanning unit MD1 will be described as an example. Moreover, in FIG. 5, it demonstrates using a XtYtZt orthogonal coordinate system. The Zt direction is a direction parallel to the irradiation center axis Le1. The Xt direction is on a plane orthogonal to the Zt direction, the substrate FS is directed from the process apparatus PR1 to the process apparatus PR2 through the exposure apparatus EX, and the Yt direction is on a plane orthogonal to the Zt direction. Therefore, the direction is orthogonal to the Xt direction. That is, the XtYtZt orthogonal coordinate system is a three-dimensional coordinate system obtained by rotating the XYZ orthogonal coordinate system of FIGS. 1 and 4 around the Y axis so that the Z axis is parallel to the irradiation center axis Le1.

  As shown in FIG. 5, in the scanning unit MD1, along the traveling direction of the beam LB1 from the incident position of the beam LB1 to the irradiated surface of the substrate FS, the reflection mirror M10, the beam expander BE, the reflection mirror M11, and the polarization Beam splitter BS, reflection mirror M12, image 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. Furthermore, in the scanning unit MD1, an optical lens G10 and a photodetector DT for detecting reflected light from the irradiated surface of the substrate FS or the rotating drum DR via the polarization beam splitter BS are provided.

  The beam LB1 incident on the scanning unit MD1 travels in the −Zt direction, and is incident on the reflection mirror M10 inclined by 45 degrees with respect to the XtYt plane. The beam LB1 incident on the scanning unit MD1 is incident on the reflection mirror M10 so that the optical axis thereof is coaxial with the irradiation center axis Le1. The reflection mirror M10 functions as an incident optical member that receives the beam LB1 and enters the scan unit MD1. The reflection mirror M10 reflects the incident beam LB1 in the −Xt direction along the optical axis AXa set parallel to the Xt axis toward the reflection mirror M11 that is separated from the reflection mirror M10 in the −Xt direction. Therefore, the optical axis AXa is orthogonal to the irradiation center axis Le1 in a plane parallel to the XtZt plane. The beam LB1 reflected by the reflection mirror M10 passes through the beam expander BE arranged along the optical axis AXa and enters the reflection mirror M11. The beam expander BE expands the diameter of the transmitted beam LB1. The beam expander BE includes a condensing lens Be1 and a collimating lens Be2 that collimates the beam LB1 that diverges after being converged by the condensing lens Be1.

  The reflection mirror M11 is disposed with an inclination of 45 degrees with respect to the YtZt plane, and reflects the incident beam LB1 in the -Yt direction toward the polarization beam splitter BS disposed away from the reflection mirror M11 in the -Yt direction. The polarization separation surface of the polarization beam splitter BS is disposed with an inclination of 45 degrees with respect to the YtZt plane. The polarization beam splitter BS reflects a P-polarized beam and transmits a linearly-polarized (S-polarized) beam polarized in a direction orthogonal to the P-polarized light. Since the beam LB1 incident on the scanning unit MD1 is a P-polarized beam, the polarization beam splitter BS reflects the beam LB1 from the reflection mirror M11 in the −Xt direction and guides it to the reflection mirror M12.

  The reflection mirror M12 is disposed with an inclination of 45 degrees with respect to the XtYt plane, and the incident beam LB1 is disposed away from the reflection mirror M12 in the −Zt direction along the optical axis AXc parallel to the Zt axis. Reflects in the -Zt direction toward M13. The beam LB1 reflected by the reflection mirror M12 passes through the image shift optical member SR, the deflection adjustment optical member DP, and the field aperture (field stop) FA arranged along the optical axis AXc, and then enters the reflection mirror M13. Incident. The image shift optical member SR two-dimensionally adjusts the center position in the cross section of the beam LB1 in a plane (XtYt plane) orthogonal to the traveling direction (optical axis AXc) of the beam LB1. The image shift optical member SR is composed of two quartz parallel plates Sr1 and Sr2 arranged along the optical axis AXc. The parallel plate Sr1 can be tilted (rotatable) about the Xt axis. Sr2 is tiltable (rotatable) around the Yt axis. The two parallel flat plates Sr1 and Sr2 are inclined about the Xt axis and the Yt axis, respectively, so that the center position in the cross section of the beam LB1 is minutely two-dimensionally on the XtYt plane orthogonal to the traveling direction of the beam LB1. shift. The parallel plates Sr1 and Sr2 are driven by an actuator (drive unit) (not shown) under the control of the control device 18.

  The deflection adjusting optical member DP finely adjusts the inclination of the beam LB1 reflected by the reflecting mirror M12 and passing through the image shift optical member SR with respect to the optical axis AXc. The deflection adjusting optical member DP is composed of two wedge-shaped prisms Dp1, Dp2 arranged along the optical axis AXc. Each of the prisms Dp1 and Dp2 is independently provided to be rotatable 360 degrees about the optical axis AXc. By adjusting the rotational angle positions of the two prisms Dp1 and Dp2, the axis of the beam LB1 reaching the reflecting mirror M13 is made parallel to the optical axis AXc, or the axis of the beam LB1 reaching the irradiated surface of the substrate FS. Is made parallel to the irradiation center axis Le1. The center position of the beam LB1 after the parallel adjustment by the two prisms Dp1 and Dp2 may be shifted two-dimensionally in a plane parallel to the cross section of the beam LB1, but this shift is an image shift. It can be returned to the original by the optical member SR. The prisms Dp1 and Dp2 are driven by an actuator (drive unit) (not shown) under the control of the control device 18.

  The beam LB1 that has passed through the image shift optical member SR and the deflection adjustment optical member DP passes through the circular aperture of the field aperture FA and reaches the reflection mirror M13. The circular aperture of the field aperture FA is a stop that cuts the skirt portion of the intensity distribution in the cross section of the beam LB1 expanded by the beam expander BE. When the field aperture FA is a variable iris diaphragm that can adjust the aperture of the circular aperture, the intensity (luminance) of the spot light SP can be adjusted.

  The reflection mirror M13 is arranged with an inclination of 45 degrees with respect to the XtYt plane, and reflects the incident beam LB1 in the + Xt direction toward the reflection mirror M14 arranged away from the reflection mirror M13 in the + Xt direction. The beam LB1 reflected by the reflection mirror M13 passes through the λ / 4 wavelength plate QW and the cylindrical lens CYa and then enters the reflection mirror M14. The reflection mirror M14 reflects the incident beam LB1 toward the polygon mirror (scanning deflection member) PM. The polygon mirror PM reflects the incident beam LB1 toward the + Xt direction toward the fθ lens FT disposed away from the polygon mirror PM toward the + Xt direction. 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 FS. Specifically, the polygon mirror PM has a rotary polyhedral surface having a rotation axis AXp extending in the Zt direction and a plurality of reflection surfaces RP (eight reflection surfaces RP in the present embodiment) formed around the rotation axis AXp. It is a mirror. 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.

  Thereby, the reflection direction (deflection direction) of the beam LB1 is continuously changed by one reflection surface RP, and the spot light SP of the beam LB1 irradiated on the irradiated surface of the substrate FS is mainly changed along the drawing line SL1. It is possible to scan one-dimensionally in the scanning direction (the width direction of the substrate FS, the Y direction). That is, the spot light SP of the pulsed beam LB1 oscillated at the oscillation frequency Fe can be scanned along one drawing line SL1 by one reflecting surface RP. Therefore, the number of scans of the spot light SP along the drawing line SL1 on the irradiated surface of the substrate FS is eight times the same as the number of the reflection surfaces RP by one rotation of the polygon mirror PM. The polygon mirror PM is rotated at a constant speed (number of rotations) by a polygon driving unit RM including a digital motor and the like under the control of the control device 18.

  The cylindrical lens CYa whose generating line is parallel to the Yt direction transmits the incident beam LB1 on the reflection surface RP of the polygon mirror PM in the non-scanning direction (Zt direction) orthogonal to the scanning direction (rotation direction) of the polygon mirror PM. Converge in. Thereby, the beam LB1 converged on the reflection surface RP of the polygon mirror PM has a slit shape in which the Yt direction is the longitudinal direction and the Zt direction is the short direction. Even if the reflection surface RP is inclined with respect to the Zt direction (inclination of the reflection surface RP with respect to the normal of the XtYt plane), the influence is suppressed by the cylindrical lens CYa and the cylindrical lens CYb described later. be able to. For example, the irradiation position (drawing line SL1) of the beam LB1 irradiated on the irradiated surface of the substrate FS can be prevented from shifting in the Xt direction due to a slight tilt error for each reflection surface RP of the polygon mirror PM. .

  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 (incident angle of the beam LB1 with respect to the optical axis AXf) θ 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 FS 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 to satisfy the relationship (distortion aberration) of y = fo · θ. 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 incident beam LB1 in the −Zt direction toward the substrate FS 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 FS is a minute spot light having a diameter of about several μm (for example, 3 μm) on the irradiated surface of the substrate FS. Converged to SP. Further, the spot light SP projected onto the irradiated surface of the substrate FS is one-dimensionally scanned along the drawing line SL1 extending in the Yt (Y) direction by the rotating polygon mirror PM. 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. Accordingly, 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 FS so as to be coaxial with the irradiation center axis Le1. In the present 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 FS. Further, at least the reflecting members (reflecting mirrors M11 to M15) and the polarizing beam splitter BS function as an optical path deflecting member that bends the optical path of the beam LB1 from the reflecting mirror M10 to the substrate FS. 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 MD1 travels in the −Zt direction and is projected onto the substrate FS after passing through a substantially U-shaped or U-shaped optical path.

  In this way, with the substrate FS being sub-scanned (conveyed) in the sub-scanning direction (+ X direction), the spot light SP of the beam LBn (LB1 to LB6) is mainly emitted by each scanning unit MDn (MD1 to MD6). By performing one-dimensional main scanning in the scanning direction (Y direction), the spot light SP can be relatively two-dimensionally scanned on the irradiated surface of the substrate FS. Therefore, a predetermined pattern can be drawn and exposed on the exposure region W of the substrate FS. Although the drawing optical elements AOMn (AOM1 to AOM6) are provided in the light introducing optical system BDUn (BDU1 to BDU6), they may be provided in the scanning unit MDn (MD1 to MD6). In this case, a drawing optical element AOMn (AOM1 to AOM6) may be provided between the reflection mirror M10 and the reflection mirror M14 in the scanning unit MDn (MD1 to MD6).

  As an example, the spot light SP is drawn on the drawing line SLn (1) while overlapping the spot light SP having an effective diameter φ of 3 μm by 1/2, that is, by 1.5 (= 3 × 1/2) μm. When irradiating the surface to be irradiated of the substrate FS along SL1 to SL6), the pulsed spot light SP is irradiated at intervals of 1.5 μm. If the effective length of the drawing lines SLn (SL1 to SL6) is 30 mm, the number of spot lights SP irradiated in one scan is 20000 (= 30 [mm] /1.5 [μm]. ) It becomes a piece. Further, assuming that the feed speed (conveyance speed) Vt of the substrate FS in the sub-scanning direction is 2.419 mm / sec, and the spot light SP is also scanned in the sub-scanning direction at intervals of 1.5 μm. The time difference Tpx between the first scan start (drawing start) time and the next scan start time along the line is about 620 μsec (≈1.5 [μm] /2.419 [mm / sec]). This time difference Tpx is a time required for the polygon mirror PM of the eight reflecting surfaces RP to rotate by an angle β (β = 45 degrees = 360 degrees / 8) for one surface. 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 rotations (= 1 / 4.96 [msec]), that is, about 12096.8 rpm.

  If the rotation angle range that can actually scan the spot light SP while the polygon mirror PM rotates by an angle β corresponding to one reflecting surface RP is α (α <β), the scanning efficiency corresponding to one reflecting surface RP. Can be expressed as α / β. In the present embodiment, since the polygon mirror PM has a regular octagonal shape having eight reflecting surfaces RP, the angle β is 45 degrees, and the scanning efficiency is represented by α / 45 degrees. The rotation angle range α that contributes to the actual scanning is the rotation angle range of the polygon mirror PM in which the beam LB1 reflected by the reflection surface RP of the polygon mirror PM is incident on the fθ lens FT and can be projected toward the substrate FS. It is. That is, the reflection surface (hereinafter referred to as a deflection reflection surface) RP of the polygon mirror PM that reflects the beam LB1 irradiated from the reflection mirror M14 toward the fθ lens FT rotates within a rotation angle range (predetermined angle range) α. The beam LB1 reflected by the deflecting reflecting surface RP is incident on the fθ lens FT and projected onto the substrate FS. This rotation angle range α is roughly determined by the focal length, aperture, position, etc. of the fθ lens FT. The larger the rotation angle range α, the longer the maximum scanning length of the drawing line SLn.

  In the present embodiment, since the rotation angle range α that contributes to actual scanning is set to 15 degrees, the scanning efficiency is 1/3 (= 15 degrees / 45 degrees). 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 this embodiment is 30 mm, the scanning time Tsp of one scanning of the spot light SP along the drawing line 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 the scanning time Tsp, the emission frequency (oscillation frequency) Fe of the beam LB from the light source device 14 is Fe≈20,000 times / 200 μsec. = 100 MHz. The maximum incident angle at which the beam LB1 reflected by one reflecting surface RP of the polygon mirror PM effectively enters the fθ lens FT is 30 degrees that is twice the rotation angle range α (centered on the optical axis AXf of the fθ lens FT). ± 15 degrees).

  The photodetector DT illustrated in FIG. 5 includes a photoelectric conversion element that photoelectrically converts incident light. A predetermined reference pattern is formed on the surface of the rotary drum DR. The portion on the rotary drum DR on which the reference pattern is formed is made of a material having a low reflectance (10 to 50%) with respect to the wavelength region of the beam LB1. The other part on the rotating drum DR where the reference pattern is not formed is made of a material having a reflectance of 10% or less or a material that absorbs light with respect to the wavelength region of the beam LB1. Therefore, when the spot light SP of the beam LB1 is irradiated from the scanning unit MD1 to the region where the reference pattern of the rotary drum DR is formed in a state where the substrate FS is not wound (or a state where the substrate FS is passed through the transparent portion), The reflected light is a cylindrical lens CYb, a reflection mirror M15, an fθ lens FT, a polygon mirror PM, a reflection mirror M14, a cylindrical lens CYa, a λ / 4 wavelength plate QW, a reflection mirror M13, a field aperture FA, a deflection adjusting optical member DP, The light passes through the image shift optical member SR and the reflection mirror M12 and enters the polarization beam splitter BS. Here, a λ / 4 wavelength plate QW is provided between the polarizing beam splitter BS and the substrate FS, specifically, between the reflection mirror M13 and the cylindrical lens CYa. As a result, the beam LB1 irradiated to the substrate FS is converted from the P-polarized light to the circularly-polarized beam LB1 by the λ / 4 wavelength plate QW, and the reflected light incident on the polarization beam splitter BS from the substrate FS is converted to the λ / The circularly polarized light is converted to S polarized light by the four-wavelength plate QW. Therefore, the reflected light from the substrate FS passes through the polarization beam splitter BS and enters the photodetector DT via the optical lens G10.

  At this time, in a state where the drawing optical element AOM1 of the light introducing optical system BDU1 is turned on, that is, in a state where the pulsed beam LB1 continuously enters the scanning unit MD1, the rotating drum DR is rotated and the scanning unit is rotated. The spot light SP is two-dimensionally irradiated on the outer peripheral surface of the rotating drum DR by the MD1 performing main scanning with the spot light SP. Therefore, the image of the reference pattern formed on the rotary drum DR can be acquired by the photodetector DT. Specifically, the control device 18 converts the intensity change of the photoelectric signal output from the photodetector DT into a clock pulse signal for pulse emission of the spot light SP (clock of the oscillation frequency Fe created in the light source device 14). One-dimensional image data in the Yt direction is obtained by digital sampling in response to the pulse signal. The control device 18 acquires this one-dimensional image data every time the spot light SP is scanned. Further, the control device 18 responds to the measurement values of the encoders EN2a and EN2b that measure the rotation angle position of the rotary drum DR in the installation orientation line Lx2 where the drawing line SL1 is arranged, for example, a fixed distance (for example, a spot) By arranging one-dimensional image data in the Yt direction in the Xt direction every 1/2) of the size φ of the light SP, two-dimensional image information on the surface of the rotary drum DR is acquired. The control device 18 measures the inclination of the drawing line SL1 of the scanning unit MD1 based on the acquired two-dimensional image information of the reference pattern of the rotating drum DR. The inclination of the drawing line SL1 may be a relative inclination between the scanning units MDn (MD1 to MD6), or may be an inclination (absolute inclination) with respect to the central axis AXo of the rotating drum DR. . In addition, it cannot be overemphasized that the inclination of each drawing line SL2-SL6 can also be measured similarly.

  Here, in the scanning units MDn (MD1 to MD6), in order to define the start point (or drawing start point) of the main scanning on the substrate FS of the spot light SP, a pulse-like origin signal (first signal) Origin sensors (first origin sensor, first origin detector) OPn (OP1 to OP6) for generating (outputting) origin signals (SZn) (SZ1 to SZ6) are provided. Each origin sensor (origin detector) OPn (OP1 to OP6) has the same configuration. Further, since the relative positional relationship between each origin sensor OPn (OP1 to OP6) and other members such as the polygon mirror PM in each scanning unit MDn (MD1 to MD6) is the same, the scanning unit MD1. The origin sensor OP1 provided in the inside will be described in detail as an example.

  6 is a diagram schematically showing the arrangement of the origin sensor OP1 arranged in the vicinity of the polygon mirror PM of the scanning unit MD1, and FIG. 7 is a diagram showing the configuration of the origin sensor OP1. The origin sensor OP1 generates a pulsed origin signal SZ1 that indicates the timing at which scanning of the spot light SP by each reflection surface RP of the polygon mirror PM can be started. The origin sensor OP1 generates an origin signal SZ1 when the rotational position of the polygon mirror PM reaches a predetermined position where the scanning of the spot light SP by the reflecting surface RP can be started. The origin sensor OP1 uses the reflecting surface RP that actually deflects the beam LB1, that is, the deflecting reflecting surface RP that is the reflecting surface RP that reflects the beam LB1 irradiated from the reflecting mirror M14 toward the fθ lens FT. An origin signal SZ1 is generated. Therefore, the origin sensor OP1 generates the origin signal SZ1 when the rotation angle position of the deflecting / reflecting surface RP that will perform the scanning of the spot light SP becomes a predetermined rotation angle position in a plane parallel to the XtYt plane. Specifically, the predetermined rotation angle position is the rotation angle position of the deflection reflection surface RP at the timing when the rotation angle position of the deflection reflection surface RP that scans the spot light SP enters the rotation angle range (predetermined angle range) α. That is.

  Therefore, the origin sensor OP1 generates the origin signal SZ1 every time the polygon mirror PM rotates 45 ° at the timing when the deflection reflection surface RP of the rotating polygon mirror PM enters the rotation angle range α. 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. In order to distinguish each reflection surface RP of the polygon mirror PM, in FIGS. 6 and 7, the reflection surface RP which is the deflection reflection surface RP is represented by RPa, and other reflection surfaces RP are separated from the reflection surface RPa. RPb to RPh are shown clockwise (around the direction opposite to the rotation direction of the polygon mirror PM). Further, since the polygon mirror PM is rotated in the clockwise direction, the reflecting surface RP that becomes the deflecting reflecting surface RP is switched in the counterclockwise direction in the order of RPa → RPb → RPc →. .

  The origin sensor OP1 includes a beam transmission system opa that emits measurement light (laser beam) Bga toward the deflection reflection surface RP (RPa in FIGS. 6 and 7) and measurement light Bga reflected by the deflection reflection surface RP. A beam receiving system opb that receives the reflected light Bgb. When receiving the reflected light Bgb, the beam receiving system opb generates (outputs) the origin signal SZ1. Specifically, as shown in FIG. 7, the beam transmission system opa includes a light source unit 20 that generates measurement light Bga in a wavelength region that is not sensitive to the photosensitive functional layer of the substrate FS, and the light source unit 20. Mirrors 22 and 24 that reflect the measurement light Bga from the light and project it onto the deflecting / reflecting surface RP (RPa in FIGS. 6 and 7) of the polygon mirror PM. The beam receiving system opb guides the light receiving unit 26 having sensitivity to the reflected light Bgb (measurement light Bga) and the reflected light Bgb from the deflection reflection surface RP (RPa in FIGS. 6 and 7) to the light receiving unit 26. Mirrors 28 and 30 and a lens system 32 that converges (condenses) the reflected light Bgb reflected by the mirror 30 into a minute spot light on the light receiving surface of the light receiving unit 26. The light receiving unit 26 includes a photoelectric conversion element that converts the spot light of the reflected light Bgb converged by the lens system 32 into an electric signal. Here, the position at which the measurement light Bga is projected onto each reflection surface RP of the polygon mirror PM is set to be the pupil plane (focal position) of the lens system 32.

  A light shielding body (not shown) having a slit opening with a very small width is provided immediately before the light receiving surface of the photoelectric conversion element in the light receiving section 26. While the rotational angle position of the deflecting reflecting surface RP (RPa in FIGS. 6 and 7) is within a predetermined angle range, the reflected light Bgb is incident on the lens system 32 and the spot light of the reflected light Bgb is received by the light receiving unit. The light shielding body in 26 is scanned in a certain direction. During the scanning, spot light of the reflected light Bgb that has passed through the slit opening of the light shield is received by the photoelectric conversion element, and the received light signal is amplified by an amplifier (not shown) and output as a pulsed origin signal SZ1. Is done.

  The beam transmission system opa and the beam reception system opb are arranged in a predetermined positional relationship. That is, the beam transmitting system opa and the beam receiving system opb are configured such that the measurement light Bga from the beam transmitting system opa is obtained when the rotation angle position of the deflecting reflection surface RP that performs the scanning of the spot light SP becomes a predetermined rotation angle position. (Reflected light Bgb) is arranged in such a positional relationship that the beam receiving system opb can receive it. For this reason, the origin sensor OP1 is disposed in the vicinity of the deflection reflection surface RP (RPa). The origin sensor OP1 (beam transmission system opa and beam reception system opb) is fixedly supported by a first support member (not shown) in the scanning unit MD1. 6 and 7 is the shaft of the digital motor RMa of the polygon drive unit RM arranged coaxially with the rotation axis AXp (see FIG. 10).

  The control device 18 controls each scanning unit MDn (MD1 to MD6) based on the origin signal SZn (SZ1 to SZ6) generated by the origin sensor OPn (OP1 to OP6) provided in each scanning unit MDn (MD1 to MD6). The scanning (drawing) start timing of the spot light SP is determined. Specifically, after the predetermined delay time (offset time) Tdn (Td1 to Td6) has elapsed from the timing when the origin sensor OPn (OP1 to OP6) generates the origin signal SZn (SZ1 to SZ6), the control device 18 The driving of the drawing optical elements AOMn (AOM1 to AOM6) based on the serial data DLn (DL1 to DL6) is started. Thereby, the drawing of the spot light SP (scanning of the spot light SP and its intensity modulation) by each scanning unit MDn (MD1 to MD6) is delayed from the generation of the origin signal SZn (SZ1 to SZ6). Will be started later. For example, the control unit 18 starts to drive the drawing optical element AOM1 based on the serial data DL1 after the delay time Td1 has elapsed from the timing at which the origin signal SZ1 is generated, so that the scanning unit MD1 can detect the spot along the drawing line SL1. Start drawing with the light SP.

  The control device 18 changes the delay time Tdn (Td1 to Td6) from when the origin signal SZn (SZ1 to SZ6) is generated to when the scanning unit MDn (MD1 to MD6) starts drawing the spot light SP. The positions of the drawing lines SLn (SLn1 to SL6) on the substrate FS can be shifted in the main scanning direction (Y direction). For example, if the delay time Tdn (Td1 to Td6) is shortened, the drawing line SLn (SL1 to SL6) is shifted in the direction opposite to the main scanning direction, and if the delay time Tdn (Td1 to Td6) is lengthened, the drawing line SLn. (SL1 to SL6) shift in the main scanning direction. The delay time Tdn (Td1 to Td6) has an initial value such that, for example, the center position of the drawing line SLn (SL1 to SL6) having a length of 30 mm becomes the center position of the maximum scanning length of 31 mm. The time is set in advance such that the drawing start point of the drawing line SLn is shifted by 0.5 mm from the scanning start point of the spot light SP at the maximum scanning length.

  As shown in FIG. 6, optical members such as a cylindrical lens CYa, a reflection mirror M14, and an fθ lens FT are disposed in the vicinity of the deflection reflection surface RP (RPa). Therefore, there is not enough space in the scanning units MDn (MD1 to MD6) to provide the first support member that supports the origin sensors OPn (OP1 to OP6) in the vicinity of the deflection reflection surface RP (RPa). Therefore, it is difficult to stably fix the origin sensor OPn (OP1 to OP6) to the rigid. That is, since there is not enough space for providing the first support member, the rigidity and strength of the first support member cannot be increased. For this reason, the first support member may vibrate due to rotation of the rotary drum DR or the polygon mirror PM, or the first support member may expand due to heat generated in the exposure apparatus EX. When the first support member vibrates or expands, the relative positional relationship among the beam transmission system opa, the beam reception system opb, and the polygon mirror PM of the origin sensor OPn (OP1 to OP6) is slightly shifted. End up. As a result, the generation timing of the origin signal SZn (SZ1 to SZ6) on the time axis deviates from the initial design generation timing. As described above, the position of the drawing lines SLn (SL1 to SL6) in the main scanning direction on the substrate FS is determined based on the generation timing of the origin signal SZn (SZ1 to SZ6) on the time axis. Accordingly, if the generation timing itself of the reference origin signal SZn (SZ1 to SZ6) is shifted on the time axis due to the displacement of the origin sensor OPn (OP1 to OP6) due to vibration or heat, the drawing lines SLn (SL1 to SL1) are shifted. SL6) is shifted in the main scanning direction, and the accuracy of the drawing exposure is lowered.

  Therefore, in the present embodiment, in order to detect a deviation in the generation timing of the origin signal SZn (SZ1 to SZ6) due to the positional deviation of the origin sensor OPn (OP1 to OP6), the polygons of the respective scanning units MDn (MD1 to MD6) are detected. As shown in FIG. 8, two sub origin sensors (second origin sensor, second origin detector) SOPan (SOPa1 to SOPa6) and SOPbn (SOPb1 to SOPb6) are provided around the mirror PM. These two sub origin sensors (origin sensors, origin detectors) SOPan (SOPa1 to SOPa6) and SOPbn (SOPb1 to SOPb6) have a reflection surface RP at a position different from the deflection reflection surface RP that reflects the drawing beam LBn. The sub origin signal (second origin signal) SZan (SZa1 to SZa6) and SZbn (SZb1 to SZb6) are generated. Regarding the two sub origin sensors SOPan (SOPa1 to SOPa6) and SOPbn (SOPb1 to SOPb6), the relative positional relationship with other members such as the polygon mirror PM in each scanning unit MDn (MD1 to MD6) is the same. Therefore, the two sub origin sensors SOPa1 and SOPb1 provided in the scanning unit MD1 will be described in detail below as an example. The sub origin sensors SOPan (SOPa1 to SOPa6) and SOPbn (SOPb1 to SOPb6) have the same basic configuration as the origin sensors OPn (OP1 to OP6). Therefore, the sub origin sensors SOPan (SOPa1 to SOPa6) and SOPbn (SOPb1 to SOPb6) are also composed of the beam transmission system opa and the beam receiving system opb. The sub origin sensors SOPan (SOPa1 to SOPa6) and SOPbn (SOPb1 to SOPb6) are supported by a second support member (not shown) in the scanning unit MDn (MD1 to MD6).

  FIG. 8 is a diagram showing an arrangement relationship among the polygon mirror PM, the origin sensor OP1, and the sub origin sensors SOPa1 and SOPb1. Also in FIG. 8, the reflection surface (deflection reflection surface) RP that deflects the beam LB1 is represented by RPa, and the other reflection surfaces RP are rotated counterclockwise from the reflection surface RPa (what is the rotation direction of the polygon mirror PM)? RPb to RPh around the opposite direction). As described above, when the origin sensor OP1 can generate the origin signal SZ1 on the deflecting reflection surface RPa, the sub origin sensors SOPa1 and SOPb1 are respectively related to the reflecting surfaces RPc and RPf other than the deflection reflecting surface RPa. , SZb1 is generated.

  The sub origin sensors SOPa1 and SOPb1 preferably generate the sub origin signals SZa1 and SZb1 using a reflection surface RP that is two or more adjacent to the deflecting reflection surface (first reflection surface) RPa. In the example shown in FIG. 8, the sub origin sensor SOPa1 generates the sub origin signal SZa1 using the reflection surface RPc two before the deflection reflection surface RPa with reference to the rotation direction of the polygon mirror PM. Similarly, the sub origin sensor SOPb1 uses the reflection surface RPf three times after the deflection reflection surface RPa, that is, the reflection surface RPf five times before the deflection reflection surface RPa, based on the rotation direction of the polygon mirror PM. An origin signal SZb1 is generated. Thus, the origin sensor OP1 and the sub origin sensors SOPa1 and SOPb1 generate (output) the origin signal SZ1 and the sub origin signals SZa1 and SZb1 by using the reflection surfaces RP at different positions of the polygon mirror PM. In the sub origin sensors SOPa1 and SOPb1, the reflecting surface (second reflecting surface) RP (RPc, RPf in FIG. 8) different from the deflecting reflecting surface (first reflecting surface) RPa is at a predetermined rotational angle position. The sub origin signals SZa1 and SZb1 are generated at the timing, but it is not necessary to generate the origin signal SZ1 and the sub origin signals SZa1 and SZb1 at exactly the same timing on the time axis.

  As shown in FIG. 6, optical members of the cylindrical lens CYa, the reflection mirror M14, and the fθ lens FT are densely arranged in the vicinity of the deflection reflection surface RP (RPa in FIG. 6). In the reflective surface RP at a position different from the surface RPa, there is a relatively large space and there is room. Accordingly, the rigidity and strength of the second support member (not shown) that supports the sub origin sensors SOPa1 and SOPb1 can be increased, and the second support member can stably stabilize the sub origin sensors SOPa1 and SOPb1. Can be supported.

  FIG. 9 is a timing chart showing an example of the relationship between the generation timing of the origin signal SZ1 by the origin sensor OP1 and the generation timing of the sub origin signals SZa1 and SZb1 by the sub origin sensors SOPa1 and SOPb1. Origin sensor OP1 and sub origin sensors SOPa1 and SOPb1 generate origin signal SZ1 and sub origin signals SZa1 and SZb1 at time Tpx intervals. This time Tpx is the time for which the polygon mirror PM rotates by one surface (45 degrees). In FIG. 9, it is assumed that the polygon mirror PM rotates at a constant rotation speed Vp unless otherwise noted. Furthermore, in FIG. 9, for the sake of simplicity, when the position of the origin sensor OP1 is not shifted (no variation), the origin signal SZ1 and the sub origin signals SZa1 and SZb1 have the same generation timing on the time axis. Is set to be Of course, the generation timing of the origin signal SZ1 and the sub origin signals SZa1 and SZb1 may be different.

  As shown in FIG. 8, the origin sensor OP1 generates an origin signal SZ1 using the deflection reflection surface RP. Therefore, the reflection surface RP which becomes the deflection reflection surface RP used for generation of the origin signal SZ1 is switched in the order of RPa → RPb → RPc →... → RPh → RPa. The sub origin sensor SOPa1 generates a sub origin signal SZa1 by using the reflection surface RP two before the deflection reflection surface RP with reference to the rotation direction of the polygon mirror PM. Therefore, the reflecting surface RP used for generating the sub origin signal SZa1 is switched in the order of RPc → RPd → RPe →... → RPb → RPc. The sub origin sensor SOPb1 generates a sub origin signal SZb1 using the reflection surface RP five before the deflection reflection surface RP with reference to the rotation direction of the polygon mirror PM. Therefore, the reflective surface RP used for generating the sub origin signal SZb1 is switched in the order of RPf → RPg → RPh →... → RPe → RPf. In FIG. 9, the reflection surface RP in which the origin signal SZ1 and the sub origin signals SZa1 and SZb1 are generated is shown in parentheses on the generated origin signal SZ1 and the sub origin signals SZa1 and SZb1. In this specification, the origin surface SZ1 and the sub origin signals SZa1 and SZb1 may be followed by a reflective surface RP that generates the origin signal SZ1 in parentheses. For example, the origin signal SZ1 and the sub origin signals SZa1 and SZb1 generated by the reflecting surface RPa may be expressed as the origin signal SZ1 (RPa) and the sub origin signals SZa1 (RPa) and SZb1 (RPa).

  Next, a method for detecting a deviation in the generation timing of the origin signal SZ1 and a method for calculating the deviation amount S1 will be described with reference to FIG. It should be noted that the deviation detection of the generation timing of the origin signal SZ1 and the calculation of the deviation amount S1 are performed for each reflecting surface RP. The calculation will be described as an example.

  The interval time (time difference) between the timing at which the origin sensor OP1 generates the origin signal SZ1 (RPd) by the reflecting surface RPd and the timing at which the sub origin sensor SOPa1 generates the sub origin signal SZa1 (RPd) by the reflecting surface RPd is Ta. To do. Further, an interval time (time difference) between the timing at which the origin sensor OP1 generates the origin signal SZ1 (RPd) by the reflecting surface RPd and the timing at which the sub origin sensor SOPb1 generates the sub origin signal SZb1 (RPd) by the reflecting surface RPd. Let Tb. That is, the time difference between the generation timing of the origin signal SZ1 (RPd) and the generation timings of the sub origin signals SZa1 (RPd) and SZb1 (RPd) generated at the timing closest to the generation timing of the origin signal SZ1 (RPd). The absolute values are set as interval times Ta and Tb, respectively. A time difference between the two interval times Ta and Tb is ΔTab (= Ta−Tb).

  When the position of the origin sensor OP1 varies, the generation timing of the origin signal SZ1 moves (time shift) as indicated by an arrow A on the time axis. As a result, the interval times Ta and Tb change from those in the initial state (a state in which the origin sensor OP1 is not displaced), and the time difference ΔTab also changes from that in the initial state.

  Therefore, the control device 18 uses the generation (output) timing of the origin signal SZ1 (RPd) and the generation (output) timing of the sub-origin signals SZa1 (RPd) and SZb1 (RPd) to determine the interval times Ta and Tb and the time difference. ΔTab is calculated sequentially. Here, in order to distinguish between the interval times Ta and Tb and the time difference ΔTab in the initial state and the interval times Ta and Tb and the time difference ΔTab obtained sequentially by the control device 18, the interval times Ta and Tb in the initial state are It is represented by ITa and ITb, and the time difference ΔTab is represented by ΔITab. And the control apparatus 18 detects the shift | offset | difference of the generation | occurrence | production timing of origin signal SZ1 (RPd) by monitoring the calculated time difference (DELTA) Tab. That is, if the calculated time difference ΔTab is equal to the time difference ΔITab (initial value) at the initial state, the control device 18 determines that the generation timing of the origin signal SZ1 (RPd) is not shifted. Then, when there is a difference between time difference ΔTab and time difference ΔITab, control device 18 determines that the generation timing of origin signal SZ1 (RPd) has deviated from the initial state. The interval times ITa and ITb and the time difference ΔITab in the initial state can be obtained in advance by experiments, calculations, and the like. At this time, the rotational speed Vp of the polygon mirror PM is precisely determined by a tachometer or encoder connected to a motor or the like that rotates the polygon mirror PM, or the frequency (period) of the sub-origin signals SZa1 and SZb1. Good.

  When the control device 18 detects a deviation in the generation timing of the origin signal SZ1 (RPd), the control device 18 sets a deviation amount (deviation time) S1 indicating how much the origin signal SZ1 (RPd) is generated since the initial state. calculate. The control device 18 determines the difference ΔTa (= ITa−Ta) between the interval time ITa (initial value) in the initial state and the measured interval time Ta, or the interval time ITb (initial value) in the initial state. A difference ΔTb (= Tb−ITb) from the measured interval time Tb is calculated, and this is set as a deviation amount S1. Therefore, when the interval times ITa and ITb in the initial state are equal to the measured interval times Ta and Tb, the deviation amount S1 is 0 and there is no deviation. In principle, the difference ΔTa and the difference ΔTb have a relationship of difference ΔTa = difference ΔTb. The control device 18 may calculate a value obtained by dividing the time difference (ΔITab−ΔTab) between the time difference ΔITab in the initial state and the measured time difference ΔTab by 2, and this may be used as the deviation amount S1. That is, the deviation amount S1 can also be obtained by a relational expression of S1 = (ΔITab−ΔTab) / 2.

  When the value of the shift amount S1 is positive (+), it means that the generation timing of the origin signal SZ1 (RPd) on the time axis has shifted in a direction that is earlier than in the initial state. Conversely, when the value of the deviation amount S1 is negative (−), it means that the generation timing of the origin signal SZ1 (RPd) on the time axis has shifted in a direction that is slower than in the initial state.

  In this embodiment, in order to correct the generation timing of the origin signal SZ1, in addition to the origin sensor OP1, two sub origin sensors SOPa1 and SOPb1 are provided. However, one sub origin sensor SOP is provided. It may be. That is, only one of the two sub origin sensors SOPa1 and SOPb1 may be provided. In this case, the control device 18 compares the interval time ITa (or ITb) in the initial state with the measured interval time Ta (or Tb), and the measured interval time Ta (or Tb) is the interval. When the time ITa (or ITb) is not equal, it is determined that the generation timing of the origin signal SZ1 has deviated from the initial state. Then, the control device 18 calculates the difference ΔTa (= ITa−Ta) or the difference ΔTb (= Tb−ITb) as the deviation amount S1.

  In this way, the control device 18 detects the origin signal SZn (SZ1 to SZ6) detected by the origin sensor OPn (OP1 to OP6) provided in each scanning unit MDn (MD1 to MD6) and the sub origin sensor SOPan ( The generation timing of the origin signal SZn (SZ1 to SZ6) using at least one of the secondary origin signals SZan (SZa1 to SZa6) and SZbn (SZb1 to SZb6) detected by SOPb1 to SOPa6), SOPbn (SOPb1 to SOPb6) Deviation amount Sn (S1 to S6) is sequentially detected (measured).

  The control device 18 adjusts the scanning start timing of the spot light SP by the scanning units MDn (MD1 to MD6) using the calculated deviation amount Sn (S1 to S6). Specifically, the control device 18 corrects the delay time Tdn (Td1 to Td6) using the deviation amount Sn (S1 to S6). The corrected delay time Tdn (Td1 to Td6) is represented by Tdn ′ (Td1 ′ to Td6 ′). This delay time Tdn ′ can be expressed by a relational expression of Tdn ′ = Tdn + Sn. Then, after the delay time Tdn ′ (Td1 ′ to Td6 ′) has elapsed from the timing at which the origin signal SZn (SZ1 to SZ6) is generated, the control device 18 draws the optical element AOMn for drawing based on the serial data DLn (DL1 to DL6). The driving of (AOM1 to AOM6) is started. Thereby, after the delay time Tdn ′ (Td1 ′ to Td6 ′) has elapsed since the origin signal SZn (SZ1 to SZ6) is generated, the scanning of the spot light SP is started and the intensity thereof is modulated. That is, drawing is started after the delay time Tdn ′ has elapsed since the origin signal SZn is generated. For example, with respect to the scanning unit MD2, after the delay time Td2 ′ (= Td2 + S2) has elapsed since the origin signal SZ2 was generated, the drawing optical element AOM2 is driven based on the serial data DL2, thereby along the drawing line SLn2. Drawing with the spot light SP is started.

  As described above, when a deviation in the generation timing of the origin signal SZn (SZ1 to SZ6) occurs, the scanning start timing of the spot light SP is adjusted using the deviation amount Sn (S1 to S6). When the deviation amount Sn (S1 to S6) is a positive value, the time from when the origin signal SZn (SZ1 to SZ6) is generated until the scanning start timing of the spot light SP is equal to the deviation amount Sn (S1 to S6). become longer. On the contrary, when the deviation amount Sn (S1 to S6) is a negative value, the time from the generation of the origin signal SZn (SZ1 to SZ6) to the scanning start timing of the spot light SP is the deviation amount Sn (S1 to S6). ) Shortened by minutes.

  It should be noted that the unevenness Sn (S1 to S6) of the generation timing of the origin signal SZn (SZ1 to SZ6) is obtained by taking the unevenness of the rotational speed Vp of the polygon mirror PM (variation of the rotational speed Vp) into consideration. ) May be requested. The unevenness of the rotation speed Vp of the polygon mirror PM may be obtained from the generation interval of the sub origin signal SZan (SZa1 to SZa6) or SZbn (SZb1 to SZb6), or the interval time Ta, the interval time Tb, or You may make it obtain | require from the fluctuation | variation of time difference (DELTA) Tab.

  FIG. 10 is a functional block diagram for performing drawing modulation of the spot light SP scanned by the scanning unit MD1 and rotation control of the polygon mirror PM of the scanning unit MD1. The control device 18 includes a control circuit 50, a drawing data output unit 52, an AOM drive circuit 54, and a polygon drive circuit 56. Since the exposure head 16 has six scanning units MDn, the control device 18 includes the control circuit 50, the drawing data output unit 52, the AOM driving circuit 54, and the polygon driving circuit 56 shown in FIG. 10 for each scanning unit MDn. Prepare for. Although only the scanning unit MD1 will be described here, the same applies to the other scanning units MD2 to MD6.

  The control circuit (drawing control unit) 50 includes a deviation detection unit 60, a rotation unevenness calculation unit 62, a deviation amount calculation unit 64, a delay time correction unit 66, and a rotation unevenness correction control unit 68. The control circuit 50 is composed of an FPGA (Field Programmable Gate Array). The origin signal SZ1 generated by the origin sensor OP1 is input to the deviation detection unit 60 and the delay time correction unit 66, and the sub origin signals SZa1 and SZb1 generated by the sub origin sensors SOPa1 and SOPb1 are input to the deviation detection unit 60. .

  The deviation detection unit 60 detects whether or not there is a deviation in the generation timing of the origin signal SZ1 using the origin signal SZ1 and one or both of the sub origin signals SZa1 and SZb1. Specifically, the deviation detecting unit 60 sequentially calculates the interval time Ta for each reflection surface RP from the origin signal SZ1 and the sub origin signal SZa1 generated for each reflection surface RP. Further, the deviation detector 60 sequentially calculates the interval time Tb for each reflection surface RP from the origin signal SZ1 and the sub origin signal SZb1 generated for each reflection surface RP. Accordingly, in the measurement of the interval time Ta, the deviation detector 60 uses the moment when one pulse signal of the sub-origin signal SZa1 is generated as a reference until the second pulse signal of the origin signal SZ1 is generated from that point. Time is measured and the interval time Tb is measured from the moment when one pulse signal of the origin signal SZ1 is generated as a reference until the third pulse signal of the sub origin signal SZb1 is generated. To do. In the present embodiment, for example, one pulse signal of each of an origin signal SZ1, a sub origin signal SZa1, and a sub origin signal SZb1 sequentially generated by a specific reflecting surface (the reflecting surface PRd in FIG. 9) is selected, Interval times Ta and Tb are measured.

  The interval time Ta is an absolute value of a time difference between the generation timing of the origin signal SZ1 and the generation timing of the sub origin signal SZa1. The interval time Tb is an absolute value of a time difference between the generation timing of the origin signal SZ1 and the generation timing of the sub origin signal SZb1. Then, the deviation detection unit 60 sequentially calculates a time difference ΔTab (= Ta−Tb) between the two calculated interval times Ta and Tb for each reflection surface RP. The deviation detection unit 60 sequentially compares the time difference ΔITab in the initial state and the calculated time difference ΔTab for each reflection surface RP, and determines that there is a deviation in the generation timing of the origin signal SZ1 when there is a deviation between the two. That is, it is determined that the position of the origin sensor OP1 has shifted. The deviation detector 60 may store the time difference ΔITab as an initial value in an internal memory (not shown), or may acquire the time difference ΔITab from an exposure controller (not shown) that constitutes a part of the control device 18. Good.

  The deviation detection unit 60 sequentially compares the interval time Ta and the initial interval time ITa for each reflection surface RP, and when deviation occurs between the two, the deviation occurs in the generation timing of the origin signal SZ1. That is, it may be determined that the position of the origin sensor OP1 has shifted. In this case, since it is not necessary to calculate the interval time Tb and the time difference ΔTab, the sub origin sensor SOPb1 need not be provided. Further, the deviation detection unit 60 compares the interval time Tb and the initial value of the interval time ITb for each reflection surface RP, and if deviation occurs between the two, the deviation occurs in the generation timing of the origin signal SZ1. It may be determined that the position of the origin sensor OP1 has shifted. In this case, since it is not necessary to calculate the interval time Ta and the time difference ΔTab, the sub origin sensor SOPa1 need not be provided. The deviation detection unit 60 may store the interval times ITa and ITb as initial values in an internal memory (not shown), or may acquire the interval times ITa and ITb from the exposure control unit.

  When the deviation detecting unit 60 detects that a deviation has occurred in the generation timing of the origin signal SZ1, at least one of the time difference ΔTab and the interval times Ta and Tb sequentially calculated for each reflection surface RP is detected with the rotation unevenness calculating unit 62 and the deviation. It outputs to the quantity calculation part 64.

  The rotation unevenness calculation unit 62 uses the sequentially calculated time difference ΔTab, interval time Ta, or interval time Tb to obtain rotation unevenness information ΔR indicating fluctuation (unevenness) in the rotation speed Vp of the polygon mirror PM of the scanning unit MD1. It calculates | requires sequentially for every reflective surface RP. The rotation unevenness calculation unit 62 calculates rotation unevenness information ΔR of the polygon mirror PM of the scanning unit MD1 from the calculated time difference ΔTab, interval time Ta, or interval time Tb. The rotation unevenness calculation unit 62 outputs the rotation unevenness information ΔR calculated sequentially to the deviation amount calculation unit 64 and the rotation unevenness correction control unit 68. The rotation unevenness information ΔR is information indicating a variation rate with respect to a specified target rotation speed. For example, the unit is [ppm] or [%]. The rotation unevenness calculating unit 62 may calculate the rotation unevenness information ΔR using the sub origin signal SZa1 (or SZb1) generated by the sub origin sensor SOPa1 (or SOPb1). In this case, at least one of the sub origin signals SZa1 and SZb1 generated by the sub origin sensors SOPa1 and SOPb1 is input to the rotation unevenness calculation unit 62, and the rotation unevenness calculation unit 62 receives the sub origin signal SZa1 (or SZb1). The rotation unevenness information ΔR is calculated from the change in the time interval of the generation timing (acquisition timing).

  Here, the polygon mirror PM is controlled so that the rotation speed Vp is constant, but the characteristics of a bearing provided for rotating the polygon mirror PM around the rotation axis AXp or windage loss during rotation (air resistance, etc.) ) Or the like, unevenness of the rotational speed Vp that affects the quality of drawing may occur.

  The deviation amount calculation unit 64 uses the calculated time difference ΔTab, interval time Ta or interval time Tb, and rotation unevenness information ΔR, and the deviation amount (deviation) of the generation timing of the origin signal SZ1 generated by the origin sensor OP1. Time) S1 is sequentially calculated for each reflecting surface RP. When using the time difference ΔTab, the deviation amount calculation unit 64 divides the time difference (ΔITab−ΔTab) between the time difference ΔITab that is the initial value and the calculated time difference ΔTab by 2, and a value obtained by multiplying the rotation unevenness information ΔR by a value. It calculates and makes this deviation | shift amount S1. When the interval time Ta is used, the deviation amount calculation unit 64 calculates a value obtained by multiplying the difference ΔTa (= ITa−Ta) between the interval time ITa as an initial value and the calculated interval time Ta by the rotation unevenness information ΔR. This is the amount of deviation S1. When the interval time Tb is used, the deviation amount calculation unit 64 calculates a value obtained by multiplying the difference ΔTb (= Tb−ITb) between the interval time ITb as the initial state and the calculated interval time Tb by the rotation unevenness information ΔR. This is the amount of deviation S1. That is, the shift amount S1 can be calculated by a relational expression of S1 = ΔR · (ΔITab−ΔTab) / 2 = ΔR · (ITa−Ta) = ΔR · (Tb−ITb). The deviation amount calculation unit 64 may store the interval times ITa, ITb or the time difference ΔITab as initial values in an internal memory (not shown), or the interval time ITa, ITa, from the exposure control unit or deviation detection unit 60 described above. ITb or time difference ΔITab may be acquired. The deviation amount calculation unit 64 outputs the deviation amount S1 sequentially calculated for each reflection surface RP to the delay time correction unit 66. When the generation timing of the origin signal SZ1 is delayed from the generation timing of the initial state (when the origin sensor OP1 is not displaced and the rotation speed of the polygon mirror PM is the target rotation speed) on the time axis, the deviation amount S1 is increased. The value is negative (-). Conversely, when the generation timing of the origin signal SZ1 is earlier than the generation timing of the initial state on the time axis, the value of the deviation amount S1 becomes positive (+).

  Here, the reason why the rotation unevenness information ΔR is taken into account in calculating the displacement amount S1 is that even when the rotation speed Vp of the polygon mirror PM is uneven, the origin sensor OP1 is not displaced. Therefore, a deviation occurs in the generation timing of the origin signal SZ1. Therefore, the rotation unevenness information ΔR is used to accurately grasp the deviation amount S1 of the generation timing of the origin signal SZ1 due to the positional deviation of the origin sensor OP1. In the case where the unevenness of the rotational speed Vp of the polygon mirror PM is not taken into consideration, ΔR = 1 may be set in the above equation for obtaining the shift amount S1.

  The delay time correction unit 66 corrects the delay time Td1, which is an offset time from when the origin signal SZ1 is generated to when actual drawing (scanning of the spot light SP and intensity modulation) is started, using the shift amount S1. . The delay time correction unit 66 generates a delay time Td1 ′ obtained by correcting the delay time Td1. The delay time correction unit 66 corrects the delay time Td1 for each reflection surface RP and sequentially generates the delay time Td1 ′. Specifically, the delay time correction unit 66 sequentially calculates the delay time Td1 ′ for each reflection surface RP using the relational expression Td1 ′ = Td1 + S1. The delay time correction unit 66 outputs the drawing enable signal STP1 to the drawing data output unit 52 and the AOM drive circuit 54 after the delay time Td1 ′ has elapsed from the generation timing of the origin signal SZ1 from the origin sensor OP1. The drawing enable signal STP1 is a signal that permits drawing (scanning of the spot light SP and its intensity modulation). The drawing enable signal STP1 is a signal that becomes H level (“1”) only for a certain period of time (at least the scanning time Tsp of the spot light SP) from the time when the delay time Td1 ′ has elapsed from the generation of the origin signal SZ1. The drawing enable signal STP1 permits drawing only during the H level period.

  The delay time Td1 is sent from the exposure control unit to the delay time correction unit 66. In principle, the exposure control unit determines the delay time Td1 so that the center position of the drawing line SLn (SL1 to SL6) having a length of 30 mm is the center position of the maximum scanning length of 31 mm. Is shifted in the main scanning direction, the delay time Td1 is determined according to the shift amount. The exposure control unit uses, for example, position information of the mark MKm (MK1 to MK4) on the substrate FS detected using an imaging signal from the alignment microscope ALGm (ALG1 to ALG4) and measurement information of the encoders EN1a and EN1b. Whether or not the drawing line SL1 is to be shifted is determined. For example, when the shape of the exposure area W is deformed (distorted) based on the position of the detected mark MKm (MK1 to MK4), the pattern for drawing exposure is also changed according to the shape of the exposure area W. It must be transformed. Therefore, it is necessary to rotate the drawing line SL1 around the irradiation center axis Le1 or to shift the drawing line SL1 in the main scanning direction.

  The drawing data output unit 52 stores the above-described pattern data (drawing data) corresponding to the scanning unit MD1. When the drawing enable signal STP1 (H level) is sent, the drawing data output unit 52 receives serial data (pixels for one column) during the period when the drawing enable signal STP1 is input (during the H level). (Logical information) DL1 is output to the AOM drive circuit 54 (see FIGS. 11A and 11B). The drawing data output unit 52 sequentially shifts the column of serial data DL1 to be output each time the drawing enable signal STP1 is sent. For example, when a drawing enable signal STP1 corresponding to the origin signal SZ1 generated by a certain reflecting surface RP is sent, the drawing data output unit 52 outputs the first column of serial data DL1 to the AOM drive circuit 54. Thereafter, when a drawing enable signal STP1 corresponding to the origin signal SZ1 generated by the next reflecting surface RP is sent, the drawing data output unit 52 converts the second column of serial data DL1 that is the next column into an AOM drive circuit. To 54. In this manner, the drawing data output unit 52 sequentially shifts the column of serial data DL1 output to the AOM driving circuit 54 every time the drawing enable signal STP1 is input. Note that the period during which the drawing data output unit 52 outputs the serial data DL1 for one column is shorter than the period during which the drawing enable signal STP1 is input (H level period).

  FIG. 11A is a time chart showing an example of the generation state of the origin signal SZ1, the drawing enable signal STP1, and the serial data DL1 when the origin sensor OP1 is not displaced. FIG. 11B shows the origin sensor OP1. 6 is a time chart illustrating an example of a generation state of an origin signal SZ1, a drawing enable signal STP1, and serial data DL1 when a positional deviation occurs. As can be seen from a comparison between FIGS. 11A and 11B, when the generation timing of the origin signal SZ1 is delayed due to the positional deviation of the origin sensor OP1, the deviation amount S1 becomes a negative value, and therefore the delay time Td1 ′ is the delay time. The time is shorter by the shift amount S1 than Td1. Therefore, the timing at which the drawing enable signal STP1 (H level) is output is the same as when the origin sensor OP1 is not displaced. Therefore, even when the position deviation of the origin sensor OP1 occurs, the output timing of the serial data DL1 to the AOM drive circuit 54 does not change, so that the drawing line SL1 is main-scanned due to the position deviation of the origin sensor OP1. Shifting in the direction can be suppressed.

  The AOM drive circuit 54 drives and controls the drawing optical element AOM1 based on the serial data DL1 sent from the drawing data output unit 52 while the drawing enable signal STP1 is at the H level. As a result, the drawing optical element AOM1 is switched based on the serial data DL1, and drawing is started. Specifically, the AOM drive circuit 54 turns on / off the drive signal (high frequency signal) output to the drawing optical element AOM1 based on the serial data DL1 during the period in which the drawing enable signal STP1 is at the H level. When the logic information of the pixel of the serial data DL1 is “1”, the AOM drive circuit 54 turns on the drive signal (high frequency signal) output to the drawing optical element AOM1, and the logic information of the pixel is “0”. In this case, the drive signal (high frequency signal) output to the drawing optical element AOM1 is turned off. Thereby, since the drawing optical element AOM1 is switched on and off, the spot light SP is scanned and its intensity is modulated. Needless to say, during the period in which the drawing enable signal STP1 and the serial data DL1 are not sent, the driving signal output from the AOM driving circuit 54 to the drawing optical element AOM1 is in an off state.

  The rotation unevenness correction control unit 68 generates a correction signal Dps for correcting the unevenness of the rotation speed Vp based on the rotation unevenness information ΔR sent from the rotation unevenness calculation unit 62. The rotation unevenness correction control unit 68 outputs the generated correction signal Dps to the polygon drive circuit 56. The polygon drive unit RM that rotates the polygon mirror PM includes a digital motor RMa capable of high-speed rotation (tens of thousands of rpm), and an encoder RMb that generates a one-pulse signal (measurement pulse signal) for each rotation of the digital motor RMa. Have. The polygon drive circuit 56 uses the measurement pulse signal from the encoder RMb to perform feedback control so that the digital motor RMa rotates at a specified speed (a constant speed), and also uses the correction signal Dps for finer detail. Correct unevenness of the rotational speed Vp. Since the rotation unevenness information ΔR is calculated for each reflection surface RP of the polygon mirror PM, the rotation unevenness correction control unit 68 has a tendency of unevenness of the rotation speed Vp that occurs during one rotation of the polygon mirror PM (generally, periodic rotation). Can be reflected in the generated correction signal Dps.

  Here, the calculation accuracy of the required deviation amount S1 will be described with specific numerical examples. The number of reflection surfaces RP of the polygon mirror PM is 8, and the maximum deflection angle (maximum incident angle) of the beam LB1 incident on the fθ lens FT is ± 15 degrees centering on the optical axis AXf of the fθ lens FT. In this case, one reflection surface RP (any one of RPa to RPh) of the polygon mirror PM is rotated by 15 degrees (rotation angle range α) by the rotation angle, thereby completing one scan by the spot light SP. To do. Further, the length of the drawing line SL1 formed by one scan of the spot light SP is 30 mm, the maximum scanning length of the drawing line SL1 is 31 mm, and the rotation speed Vp of the polygon mirror PM is about 1,2096.8 rpm.

  In this case, the time Tsp when the spot light SP crosses the drawing line SL1 with 30 mm, that is, the time Tsp when the spot light SP scans the drawing line SL1 with 30 mm is Tsp = (60 [seconds] /1209.86.8 [rpm]. ) · (15 degrees / 360 degrees) × (30 [mm] / 31 [mm]), and the time Tsp is about 200 μsec. During this time Tsp, the spot light SP is scanned by 30 mm (= 30000 μm). Therefore, when the minimum dimension (consisting of a plurality of pixels) of the pattern drawn on the substrate FS is 9 μm, this minimum dimension is used. The scanning time Tcs of the spot light SP for drawing a 9 μm line pattern is obtained by Tcs = Tsp · (9 [μm] / 30000 [μm]). Therefore, the scanning time Tcs is about 60 nsec. Further, since the overlay accuracy when overlaying and exposing a new pattern to the underlying pattern layer already formed on the substrate FS is 1/5 or less of the minimum dimension of 9 μm, the line of 9 μm The scanning time of the spot light SP corresponding to the overlay accuracy (± 1.8 μm) in the case of the pattern is 12 nsec from Tcs / 5. For this reason, the delay time Td1 ′ and the shift amount S1 need to be calculated with an accuracy or reproducibility of 12 nsec or less. In the present embodiment, by providing the sub origin sensors SOPa1 and SOPb1, it is possible to monitor the deviation amount S1 and the rotation unevenness information ΔR due to the position deviation of the origin sensor OP1 with high accuracy.

  As described above, the exposure apparatus (beam) that scans the spot light SP one-dimensionally on the irradiated surface while projecting the spot light SP of the beam LB from the light source device 14 onto the irradiated surface of the substrate (object) FS. The scanning device EX irradiates the polygon mirror (rotating polygon mirror) PM having a plurality of reflecting surfaces RP for deflecting the beam LB for one-dimensional scanning, and the measuring light Bga to the reflecting surface RP of the polygon mirror PM. When the reflecting surface RP comes to a predetermined rotation angle position, a plurality of origin sensors (the origin sensor OPn and the sub origin) output the origin signal SZ (SZn, SZan, SDnb) by receiving the reflected light Bgb of the measurement light Bga. Sensors SOPan, SOPbn). Each of the plurality of origin sensors irradiates the measurement light Bga toward different reflection surfaces RP of the polygon mirror PM, and outputs an origin signal SZ for each different reflection surface RP. Thus, by providing a plurality of origin sensors and using the origin signal SZ output from the plurality of origin sensors, it is possible to accurately determine the drawing start timing.

  The plurality of origin sensors use the reflection surface RP that deflects the beam LB and performs one-dimensional scanning of the spot light SP among the plurality of reflection surfaces RP of the polygon mirror PM, and uses an origin signal (first origin signal) SZn. Sub-origin signal (second origin signal) SZan by using an origin sensor (first origin sensor) OPn that outputs and a reflecting surface RP at a position different from the reflecting surface RP that performs one-dimensional scanning of the spot light SP. , SZbn output sub origin sensors (second origin sensors) SOPan, SOPbn. Accordingly, it is possible to correct the generation timing of the origin signal SZn using the sub origin signals SZan and SZbn, and to suppress the drawing line SLn from shifting in the main scanning direction due to the positional deviation of the origin sensor OPn. Can do.

  Using the output timing of the origin signal SZn and the output timings of the sub origin signals SZan and SZbn, a control device 18 is provided that detects a deviation in the output timing of the origin signal SZn due to a position deviation of the origin sensor OPn. Thereby, the exposure apparatus EX can accurately detect whether or not a deviation has occurred in the generation timing of the origin signal SZn.

  When the control device 18 detects a deviation in the output timing of the origin signal SZn due to the positional deviation of the origin sensor OPn, the controller 18 calculates a deviation amount Sn in the output timing of the origin signal SZn. Thus, the exposure apparatus EX can accurately calculate the deviation amount Sn of the generation timing of the origin signal SZn.

  The controller 18 determines the scanning start timing of the spot light SP based on the output timing of the origin signal SZn, and when the deviation amount Sn is calculated, the scanning start timing of the spot light SP is calculated using the deviation amount Sn. adjust. Accordingly, the drawing start timing can be accurately determined, and the drawing line SLn can be prevented from shifting in the main scanning direction due to the positional deviation of the origin sensor OPn.

  A plurality of sub origin sensors SOPan and SOPbn are provided, and each of the plurality of sub origin sensors SOPan and SOPbn outputs sub origin signals SZan and SZbn using reflection surfaces RP at different positions. As a result, for example, even when one of the sub origin sensors SOPan and SOPbn fails, the drawing start timing can be determined accurately, and the drawing line SLn is determined due to the positional deviation of the origin sensor OPn. Shifting in the main scanning direction can be suppressed.

  As described above, in the present embodiment, an exposure apparatus (pattern that draws a pattern on the substrate FS by scanning the beam LB on the substrate FS and modulating the beam LB according to the pattern data during scanning. The drawing apparatus EX includes a polygon mirror PM having a plurality of reflection surfaces RP for deflecting the beam LB and one of the first reflection surfaces RPa among the plurality of reflection surfaces RP of the polygon mirror PM for scanning. While rotating within the predetermined angle range α, an fθ lens (projection optical system) FT that enters the beam LB reflected by the first reflecting surface RPa and projects it toward the object, and the first reflecting surface RPa. An origin sensor (first origin detector) OPn that outputs an origin signal SZn that represents a point in time when reaching a predetermined angle range α, and a second reaction different from the first reflecting surface RPa among the plurality of reflecting surfaces RP of the polygon mirror PM. A sub-origin sensor (second origin detector) SOPan (or SOPbn) that outputs a sub-origin signal SZan (or SZbn) indicating a point in time when the surface RPc (or RPf) has reached a predetermined rotation angle position; And a control circuit (drawing control unit) 50 for controlling the start timing of the modulation of the beam LB based on the sub origin signal SZan (or SZbn). As a result, the drawing start timing can be accurately determined, and the drawing line SLn is shifted in the main scanning direction due to a positional shift caused by a drift with time of the origin sensor OPn or a gentle vibration. Can be suppressed.

DESCRIPTION OF SYMBOLS 10 ... Device manufacturing system 12 ... Board | substrate conveyance mechanism 14 ... Light source device 16 ... Exposure head 18 ... Control apparatus 20 ... Light source part 26 ... Light receiving part 50 ... Control circuit 52 ... Drawing data output part 54 ... AOM drive circuit 56 ... Polygon drive circuit 60 ... Deviation detection unit 62 ... Rotation unevenness calculation unit 64 ... Deviation amount calculation unit 66 ... Delay time correction unit 68 ... Rotation unevenness correction control unit ALGm (ALG1-ALG4) ... Alignment microscope AOMn (AOM1-AOM6) ... Optical element for drawing AXo ... Center axis AXp ... Rotation axis BDUn (BDU1 to BDU6) ... Light introducing optical system CYa, CYb ... Cylindrical lens DR ... Rotation drum ENja (EN1a-EN3a), ENjb (EN1b-EN3b) ... Encoder EX ... Exposure device FS ... Substrate FT ... fθ lens LB, LBn (LB1 to LB6) ... B Len (Le1 to Le6) ... Irradiation center axis Lx1, Lx2, Lx3 ... Installation orientation line MDn (MD1 to MD6) ... Scanning unit MKm (MK1 to MK4) ... Mark OPn (OP1 to OP6) ... Origin sensor PM ... Polygon mirror RP (RPa to RPh) ... reflective surface SDa, SDb ... scale portion SLn (SL1 to SL6) ... drawing lines SOPan (SOPa1 to SOPa6), SOPbn (SOPb1 to SOPb6) ... sub origin sensor SP ... spot light STP1 ... drawing enable signal SZn (SZ1 to SZ6) ... Origin signal SZan (SZa1 to SZa6), SZbn (SZb1 to SZb6) ... Sub origin signal UB ... Body frame W ... Exposure area

Claims (13)

A beam scanning device that scans the spot light in a one-dimensional manner on the irradiated surface while projecting the spot light of the beam from the light source device onto the irradiated surface of the object,
A rotating polygon mirror having a plurality of reflecting surfaces for deflecting the beam for the one-dimensional scanning;
A plurality of origin sensors that irradiate measurement light onto the reflection surface of the rotary polygon mirror and output an origin signal by receiving the reflection light of the measurement light when the reflection surface reaches a predetermined rotation angle position;
With
Each of the plurality of origin sensors irradiates the measurement light toward different reflection surfaces of the rotary polygon mirror, and outputs the origin signal for each of the different reflection surfaces. The beam scanning device according to claim 1,
The plurality of origin sensors output a first origin signal using the reflecting surface that deflects the beam and performs the one-dimensional scanning of the spot light among the plurality of reflecting surfaces of the rotary polygon mirror. And a second origin sensor that outputs a second origin signal using the reflective surface at a position different from the reflective surface that performs the one-dimensional scanning of the spot light. Beam scanning device. The beam scanning device according to claim 2,
A control device for detecting a deviation in the output timing of the first origin signal due to a positional deviation of the first origin sensor, using the output timing of the first origin signal and the output timing of the second origin signal. A beam scanning device. The beam scanning device according to claim 3,
The control device calculates a deviation amount of the output timing of the first origin signal when detecting a deviation of the output timing of the first origin signal due to a position deviation of the first origin sensor. apparatus. The beam scanning apparatus according to claim 4,
The control device determines a scanning start timing of the spot light based on an output timing of the first origin signal, and when the deviation amount is calculated, the spot light is scanned using the deviation amount. A beam scanning device that adjusts the start timing. The beam scanning apparatus according to any one of claims 2 to 5,
A plurality of second origin sensors,
Each of the plurality of second origin sensors outputs the second origin signal using the reflection surfaces at different positions. A beam scanning method of scanning the spot light in a one-dimensional manner on the irradiated surface while projecting the spot light of the beam from the light source device onto the irradiated surface of the object,
A deflection step of deflecting the beam for the one-dimensional scanning using a rotating polygon mirror;
By irradiating at least two different reflecting surfaces of the rotary polygon mirror with measurement light, and when each of the at least two reflecting surfaces is at a predetermined rotation angle position, the reflected light of the measurement light is received. Outputting at least two origin signals corresponding to each of the at least two reflecting surfaces;
A beam scanning method. The beam scanning method according to claim 7, comprising:
The output step includes
A first output step of outputting a first origin signal using the reflecting surface that deflects the beam and performs the one-dimensional scanning of the spot light;
A second output step of outputting a second origin signal using the reflection surface at a position different from the reflection surface that performs the one-dimensional scanning of the spot light;
A beam scanning method. The beam scanning method according to claim 8, comprising:
A beam scanning method including a detection step of detecting a shift in output timing of the first origin signal using the output timing of the first origin signal and the output timing of the second origin signal. The beam scanning method according to claim 9, comprising:
A beam scanning method including a calculation step of calculating a deviation amount of the output timing of the first origin signal when a deviation of the output timing of the first origin signal is detected. The beam scanning method according to claim 10, comprising:
The spot light scanning start timing is determined based on the output timing of the first origin signal, and when the deviation amount is calculated, the spot light scanning start timing is adjusted using the deviation amount. A beam scanning method including a determination step. The beam scanning method according to any one of claims 7 to 11,
The second output step is a beam scanning method in which a plurality of the second origin signals are output using the reflection surfaces at different positions. A pattern drawing apparatus for drawing a pattern on the object by scanning the beam on the object, modulating the beam according to pattern information during scanning,
A rotating polygon mirror having a plurality of reflecting surfaces for deflecting the beam for the scanning;
While the first reflecting surface of any one of the plurality of reflecting surfaces of the rotary polygon mirror is rotated within a predetermined angle range, the beam reflected by the first reflecting surface is incident and the object is incident. A projection optical system that projects toward
A first origin detector for outputting a first origin signal representing a time point when the first reflecting surface reaches the predetermined angle range;
A second origin detector for outputting a second origin signal representing a point in time when a second reflecting surface different from the first reflecting surface of the plurality of reflecting surfaces of the rotary polygon mirror has reached a predetermined rotation angle position; ,
A drawing control unit for controlling a start timing of modulation of the beam based on the first origin signal and the second origin signal;
A pattern drawing apparatus.

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