CN108885337B - Light beam scanning device and pattern drawing device - Google Patents

Abstract

A scanning unit (Un) that projects a light beam (LBn) deflected by a Polygon Mirror (PM) whose reflection surface angle changes onto a substrate (P) is provided with: a re-reflection optical system (CY2, M10) that reflects the 1 st reflected light beam (LBn) that was initially reflected by the Polygon Mirror (PM) to generate a 2 nd reflected light beam (LBn) that is directed toward the Polygon Mirror (PM), and that converges the 2 nd reflected light beam (LBn) in a non-deflection direction that intersects the deflection direction of the Polygon Mirror (PM); and scanning optical systems (FT, CY3) that receive the 2 nd reflected light beam (LBn), reflect the 3 rd reflected light beam (LBn) obtained by the Polygon Mirror (PM) again, and emit the reflected light beam toward the substrate (P).

Description

Light beam scanning device and pattern drawing device

Technical Field

The present invention relates to a light beam scanning device that scans a spot of a light beam irradiated onto an irradiation surface of an object, and a pattern drawing device that draws an exposure predetermined pattern using the light beam scanning device.

Background

Conventionally, there is known a high-speed printer for business use, for example, an optical scanning device disclosed in japanese patent application laid-open No. s 61-7818, which is described below, in order to project a spot of a laser beam onto an object (target object) such as a photosensitive drum, move the object in a sub-scanning direction orthogonal to a main scanning line direction while performing main scanning in a one-dimensional direction by a rotating polygon mirror, and draw a desired pattern or image (characters, figures, photographs, etc.) on the object.

Jp 61-7818 a discloses that a rotary polygon mirror having a deflection surface that rotates about a rotation axis and 2 correction plane mirrors facing the deflection surface such that a ridge line is orthogonal to the rotation axis are provided, and an incident light beam to the deflection surface of the rotary polygon mirror is guided to a scanning surface as a scanning light beam by reciprocating the incident light beam once between the correction plane mirrors and the rotary polygon mirror, thereby optically correcting distortion of the scanning line due to, for example, a surface inclination of the deflection surface. In jp 61-7818 a, the arrangement of 2 correction mirrors and the incident angle of an incident beam are set so that the angle (emission angle) between the projection image of a scanning beam onto a plane including a rotation axis and perpendicular to the ridge line of the 2 correction mirrors and the plane perpendicular to the rotation axis is 5 ° to 15 °.

As shown in fig. 2 (or fig. 8 to 10) of jp 61-7818 a, when the light flux that is first incident on the deflecting surface of the rotary polygon mirror and the light flux that is reflected by the 2-piece correcting plane mirror and is second incident on the deflecting surface of the rotary polygon mirror are set to the same position on the deflecting surface in the direction of the rotation axis, the angle (included angle β) formed by the 2-piece correcting plane mirrors is an acute angle of less than 90 °. In this case, if the deflection surface of the rotary polygon mirror is inclined with respect to a plane parallel to the rotation axis, the position of the light flux reflected by the 2-piece correcting plane mirror and returned to the deflection surface of the rotary polygon mirror with respect to the light flux that first entered the deflection surface of the rotary polygon mirror is greatly displaced in the direction of the rotation axis. Therefore, it is necessary to secure a dimension in the rotation axis direction of the deflection surface of the rotary polygon mirror in advance so as to cope with the displacement. This limits the reduction in weight of the rotary polygon mirror, and limits the upper limit of the rotational speed of the rotary polygon mirror.

Disclosure of Invention

A 1 st aspect of the present invention is an optical beam scanning device that projects a light beam deflected by a movable reflecting member whose reflecting surface angle changes, onto an irradiation object, and includes: a re-reflection optical system including a 1 st optical member that reflects a 1 st reflected light beam that is first reflected by the movable reflection member to generate a 2 nd reflected light beam that is directed toward the movable reflection member, and converges the 2 nd reflected light beam in a non-deflecting direction that intersects a deflecting direction of the light beam generated by the movable reflection member; and a scanning optical system that receives the 2 nd reflected light beam, reflects the 3 rd reflected light beam again by the movable reflecting member, and emits the 3 rd reflected light beam toward the irradiation object.

A 2 nd aspect of the present invention is an optical beam scanning device for projecting an optical beam deflected by a movable reflecting member having a plurality of reflecting surfaces with mutually different directions, the reflecting surfaces being directed to an irradiation object, the optical beam scanning device including: a re-reflection optical system that generates a 1 st reflected light beam reflected by a 1 st reflection surface of the movable reflection member and a 2 nd reflected light beam heading toward a 2 nd reflection surface of the movable reflection member different from the 1 st reflection surface; and a scanning optical system which is incident on the 3 rd reflected light beam reflected by the 2 nd reflecting surface of the movable reflecting member and projects the 3 rd reflected light beam onto the irradiation target.

A 3 rd aspect of the present invention is a pattern drawing apparatus that uses the optical beam scanning apparatus of the 1 st or 2 nd aspect of the present invention in a state where a substrate is moved in a predetermined direction, projects the optical beam onto the substrate as the irradiation object, and scans the optical beam in a main scanning direction intersecting the predetermined direction, thereby drawing a pattern on the substrate.

Drawings

Fig. 1 is a diagram showing a schematic configuration of a device manufacturing system including an exposure apparatus for performing exposure processing on a substrate according to embodiment 1.

Fig. 2 is a detailed view of the drum shown in fig. 2 in a state where the substrate is wound.

Fig. 3 is a diagram showing a drawing line of a light spot scanned on a substrate and an alignment mark formed on the substrate.

Fig. 4 is a schematic configuration diagram of the beam switching unit shown in fig. 1.

Fig. 5 is a diagram showing a specific configuration around the optical element for selection and the incidence mirror shown in fig. 4.

Fig. 6 is a perspective view showing a configuration of the scanning unit shown in fig. 1.

Fig. 7 is a view of the scanning unit shown in fig. 6 as viewed from the + Y direction.

Fig. 8 is a diagram illustrating a reflection angle of a light flux when the reflection surface of the polygon mirror PM shown in fig. 6 reflects 2 times.

Fig. 9 is a diagram illustrating the rotation angle of the polygon mirror required for 1 scan.

Fig. 10 is an electrical configuration diagram of the exposure apparatus shown in fig. 1.

Fig. 11 is a view showing the configuration of a scanner unit according to modification 1 of embodiment 1.

Fig. 12 is a diagram showing a configuration for reflecting a beam 2 times by a reflection surface of a polygon mirror in modification 2 of embodiment 1.

Fig. 13A is a view of the configuration of the scanning unit according to embodiment 2 as viewed from the-Y direction, and fig. 13B is a view of the configuration of the scanning unit according to embodiment 2 as viewed from the + Z direction.

Fig. 14 is a diagram showing an example of the arrangement of the scanning unit in modification 1 of embodiment 2.

Fig. 15 is a diagram of the structure of embodiment 3 for making the polygon mirror 2 reflect the drawing light beam once.

Fig. 16 is a diagram showing a configuration for reflecting a beam by the polygon mirror 2 in modification 1 of embodiment 3.

Fig. 17 is a diagram showing the configuration of a scanner unit according to a modification of embodiments 1 to 3.

Detailed Description

The optical beam scanning device and the pattern drawing device according to the aspects of the present invention will be described in detail below with reference to the accompanying drawings, which illustrate preferred embodiments. Furthermore, the aspects of the present invention are not limited to the embodiments, and various changes and modifications may be added. That is, the components described below include substantially the same components that can be easily assumed by the manufacturer, and the components described below can be appropriately combined. Various omissions, substitutions, and changes in the components can be made without departing from the spirit of the invention.

[ embodiment 1 ]

Fig. 1 is a schematic configuration diagram of a device manufacturing system 10 including an exposure apparatus EX for performing an exposure process on a substrate (irradiation target) P according to embodiment 1. In the following description, unless otherwise specified, an XYZ rectangular coordinate system is set in which the direction of gravity is the Z direction, and the X direction, the Y direction, and the Z direction are described in accordance with arrows shown in the drawings.

The device manufacturing system 10 is a system (substrate processing apparatus) that performs a predetermined process (exposure process, etc.) on the substrate P to manufacture an electronic device. The device manufacturing system 10 is a manufacturing system of a production line for manufacturing, for example, a flexible display, a film-shaped touch panel, a film-shaped color filter for a liquid crystal display panel, a flexible wiring, a flexible sensor, or the like, which is an electronic device. Hereinafter, a flexible display will be explained as an electronic device on the premise of a flexible display. Examples of flexible displays include organic EL displays and liquid crystal displays. The device manufacturing system 10 has a so-called Roll-To-Roll (Roll To Roll) type structure in which a substrate P is fed from a supply Roll (not shown) that winds a soft (flexible) sheet-like substrate (sheet substrate) P into a Roll, various processes are continuously performed on the fed substrate P, and thereafter, the substrate P after various processes is wound around a recovery Roll (not shown). Therefore, the substrate P after various processes is in a state where a plurality of devices are connected in the substrate P conveyance direction, and is a substrate for multi-chamfering. The substrate P sent from the supply roll is subjected to various processes in the manufacturing apparatus PR1, the exposure apparatus EX, and the manufacturing apparatus PR2 in this order, and is wound up by the recovery roll. The substrate P has a belt-like shape in which the moving direction (transfer direction) of the substrate P is the longitudinal direction (long dimension) and the width direction is the short direction (short dimension).

In the present embodiment, the X direction is a direction in which the substrate P is directed from the supply roller to the recovery roller in a horizontal plane orthogonal to the Z direction, and is a longitudinal direction (longitudinal direction) of the substrate P. The Y direction is a direction orthogonal to the X direction in a horizontal plane orthogonal to the Z direction, and is a width direction (short dimension direction) of the substrate P. the-Z direction is a direction in which gravity acts (gravity direction), and the conveyance direction of the substrate P is the + X direction.

For example, a resin film or foil (foil) made of metal such as stainless steel or alloy is used as the substrate P. As the material of the resin film, for example, at least 1 or more selected from the group consisting of a polyethylene resin, a polypropylene resin, a polyester resin, an ethylene-vinyl alcohol copolymer resin, a polyvinyl chloride resin, a cellulose resin, a polyamide resin, a polyimide resin, a polycarbonate resin, a polystyrene resin, and a vinyl acetate resin can be used. The thickness or rigidity (young's modulus) of the substrate P may be in a range such that the substrate P does not have creases or irreversible wrinkles due to bending when passing through the transfer path of the device manufacturing system 10. As a base material of the substrate P, a film of PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or the like having a thickness of 10 to 200 μm or less is a typical preferable thin sheet substrate.

Since the substrate P may be heated in each process performed in the device manufacturing system 10, it is preferable to select a material having a thermal expansion coefficient not too large. For example, the coefficient of thermal expansion can be suppressed by mixing an inorganic filler with a resin film. The inorganic filler may be, for example, titanium oxide, zinc oxide, aluminum oxide, silicon oxide, or the like. The substrate P may be a single layer of an extra thin glass having a thickness of about 100 μm or about 35 μm manufactured by a float method or the like, or may be a laminate in which the resin film, foil, or the like is laminated on the extra thin glass.

The flexibility of the substrate P means that the substrate P can be bent without being sheared or broken even if a force of a self weight is applied to the substrate P. Also, the property of bending by a force of its own weight is included in flexibility. The degree of flexibility varies depending on the material, size, and thickness of the substrate P, the layer structure formed on the substrate P, and the environment such as temperature and humidity. In short, the flexibility range can be defined as long as the substrate P can be smoothly transported without being bent and without causing creases or damage (causing chipping or cracking) when the substrate P is accurately wound around the transport direction changing members such as various transport rollers and drums provided on the transport path in the device manufacturing system 10 of the present embodiment.

The manufacturing apparatus (processing apparatus) PR1 performs the processing of the preceding step on the substrate P sent to the exposure apparatus EX while conveying the substrate P conveyed from the supply roller toward the exposure apparatus EX at a predetermined speed in a conveyance direction (+ X direction) along the longitudinal direction. By the processing in the preceding step, the substrate P sent to the exposure apparatus EX becomes a substrate (photosensitive substrate) having a photosensitive functional layer (photosensitive layer) formed on the surface thereof.

The photosensitive functional layer is applied as a solution onto the substrate P and dried to form a layer (film). The photosensitive functional layer is typically a photoresist (liquid or dry film), but as a material not requiring development treatment, there are a photosensitive silane coupling agent (SAM) in which hydrophilicity/repellency of a portion irradiated with ultraviolet rays is modified, a photosensitive reducing agent in which a reducing group is exposed to a portion irradiated with ultraviolet rays, and the like. When a photosensitive silane coupling agent is used as the photosensitive functional layer, the pattern portion exposed to ultraviolet light on the substrate P is modified from lyophilic to lyophilic. Therefore, by selectively applying a liquid containing a conductive ink (ink containing conductive nanoparticles such as silver or copper) or a semiconductor material to the portion having lyophilic properties, a pattern layer to be an electrode constituting a Thin Film Transistor (TFT) or the like, a semiconductor, and an insulating or connecting wiring can be formed. When a photosensitive reducing agent is used as the photosensitive functional layer, the plating reducing group is exposed to the pattern portion exposed to ultraviolet light on the substrate P. Therefore, immediately after exposure, the substrate P is immersed in a plating solution containing palladium ions or the like for a fixed time, thereby forming (depositing) a pattern layer of palladium. Such plating treatment is additive (additive) production, but in addition to this, etching treatment may be assumed as subtractive (reactive) production. In this case, the substrate P sent to the exposure apparatus EX may be formed by depositing a metal thin film of aluminum (Al) or copper (Cu) on the entire surface of a base material PET or PEN, or selectively depositing a photoresist layer thereon.

The exposure apparatus (processing apparatus) EX is a processing apparatus that performs exposure processing on the substrate P while conveying the substrate P conveyed from the manufacturing apparatus PR1 in the conveyance direction (+ X direction) at a predetermined speed toward the manufacturing apparatus PR 2. The exposure apparatus EX irradiates the surface of the substrate P (the surface of the photosensitive functional layer, i.e., the photosensitive surface) with a light pattern corresponding to a pattern for an electronic device (e.g., a pattern of an electrode, a wiring, or the like of a TFT constituting the electronic device). Thereby, a latent image (modified portion) corresponding to the pattern is formed on the photosensitive functional layer.

In the present embodiment, the exposure apparatus EX is an exposure apparatus of a direct imaging system without using a mask, that is, an exposure apparatus of a so-called raster scanning system (pattern writing apparatus). The exposure apparatus EX scans (main-scans) a spot SP of a pulse-shaped light beam LB (pulse beam) for exposure one-dimensionally in a predetermined scanning direction (Y direction) on an irradiated surface (photosensitive surface) of a substrate P while conveying the substrate P in the + X direction (predetermined direction, sub-scanning direction), and modulates (turns on/off) the intensity of the spot SP at high speed in accordance with pattern data (drawing data, pattern information). Thereby, a light pattern corresponding to a predetermined pattern of electronic devices, circuits, wirings, and the like is drawn and exposed on the irradiated surface of the substrate P. That is, in the sub-scanning of the substrate P and the main scanning of the spot SP, the spot SP is relatively two-dimensionally scanned on the irradiation surface (surface of the photosensitive functional layer) of the substrate P, and a predetermined pattern is drawn and exposed on the irradiation surface of the substrate P. Since the substrate P is transported along the transport direction (+ X direction), a plurality of exposure fields W of the exposure pattern by the exposure apparatus EX are provided at predetermined intervals along the longitudinal direction of the substrate P (see fig. 3). Since the electronic device is formed in the exposure region W, the exposure region W is also a device formation region.

The manufacturing apparatus (processing apparatus) PR2 performs processes (for example, plating, development, etching, and the like) of subsequent steps on the substrate P subjected to the exposure process by the exposure apparatus EX while conveying the substrate P conveyed from the exposure apparatus EX toward the recovery roller at a predetermined speed in a conveyance direction (+ X direction) along the longitudinal direction. Through the subsequent steps, a device pattern layer is formed on the substrate P.

Next, the exposure apparatus EX will be described in further detail. The exposure apparatus EX is housed in a temperature-controlled chamber ECV. The temperature-control chamber ECV maintains the inside at a predetermined temperature and a predetermined humidity, thereby suppressing a change in shape of the substrate P conveyed inside due to the temperature, and suppressing moisture absorption of the substrate P, electrostatic charging generated during conveyance, and the like. The temperature-controlled chamber ECV is disposed on the installation surface E of the manufacturing plant via passive or active vibration-resistant units SU1 and SU 2. The anti-vibration units SU1 and SU2 reduce vibration from the installation surface E. The installation surface E may be the floor of a factory or a surface on an installation base (pedestal) which is installed on the floor in a special manner to make a horizontal surface. The exposure apparatus EX includes at least a substrate conveyance mechanism 12, a light source device 14, a light beam switching unit BDU, a drawing head 16, a control device 18, a plurality of alignment microscopes AMm (where m is 1, 2, 3, and 4), and a plurality of encoder heads ENja and ENjb (where j is 1, 2, and 3). The controller 18 controls each part of the exposure apparatus EX. The control device 18 includes a computer, a recording medium on which a program is recorded, and the computer executes the program to function as the control device 18 of the present embodiment.

The substrate transfer mechanism 12 is a part of a substrate transfer apparatus constituting the device manufacturing system 10, and transfers the substrate P transferred from the manufacturing apparatus PR1 at a predetermined speed in the exposure apparatus EX, and then sends the substrate P to the manufacturing apparatus PR2 at a predetermined speed. The substrate conveyance mechanism 12 includes an edge position controller EPC, a drive roller R1, a tension adjustment roller RT1, a drum (cylindrical drum) DR, a tension adjustment roller RT2, a drive roller R2, and a drive roller R3 in this order from the upstream side (the-X direction side) in the conveyance direction of the substrate P. The conveyance path of the substrate P conveyed in the exposure apparatus EX is defined by an edge position controller EPC which mounts the substrate P on the substrate conveyance mechanism 12, drive rollers R1 to R3, tension adjustment rollers RT1 and RT2, and a drum (cylindrical drum) DR.

The edge position controller EPC adjusts the position in the width direction (Y direction and the short-dimension direction of the substrate P) of the substrate P conveyed from the manufacturing apparatus PR 1. That is, the edge position controller EPC adjusts the position of the substrate P in the width direction by moving the substrate P in the width direction so that the position of the end (edge) of the substrate P in the width direction, which is conveyed in a state where a predetermined tension is applied, is within a range (allowable range) of about ± ten μm to several tens μm from the target position. The edge position controller EPC includes a roller on which the substrate P is suspended with a predetermined tension applied thereto, and an edge sensor (edge detection unit), not shown, that detects the position of an edge (edge) of the substrate P in the width direction. The edge position controller EPC moves the roller of the edge position controller EPC in the Y direction based on the detection signal detected by the edge sensor, thereby adjusting the position of the substrate P in the width direction. The drive roller (nip roller) R1 rotates while holding both the front and back surfaces of the substrate P conveyed from the edge position controller EPC, and conveys the substrate P toward the drum DR. The edge position controller EPC may also appropriately adjust the position of the substrate P in the width direction so that the longitudinal direction of the substrate P wound around the drum DR is always orthogonal to the central axis AXo of the drum DR, and appropriately adjust the parallelism between the rotation axis of the drum of the edge position controller EPC and the Y axis so as to correct the slope error in the traveling direction of the substrate P.

The drum DR has a central axis AXo extending in the Y direction intersecting the Z direction in which gravity acts, and a cylindrical outer peripheral surface having a constant radius from the central axis AXo. The drum DR supports (holds) the substrate P so as to bend a part of the substrate P in a cylindrical surface shape along the outer peripheral surface (circumferential surface) and conveys the substrate P in the + X direction while rotating about the central axis AXo. The drum DR supports, on its outer peripheral surface, a region (portion) on the substrate P on which the light beam LB (spot SP) from the drawing head 16 is projected. The drum DR supports (holds in close contact with) the substrate P from a surface (back surface) side opposite to a surface (surface on which the photosensitive surface is formed) on which the electronic components are formed. On both sides of the drum DR in the Y direction, shafts Sft supported by annular bearings are provided so that the drum DR rotates about the central shaft AXo. The drum DR rotates at a fixed rotational speed around the center shaft AXo by applying rotational torque to the shaft Sft from a not-shown rotational drive source (e.g., a motor, a speed reduction mechanism, or the like) controlled by the control device 18. For convenience, a plane including the central axis AXo and parallel to the YZ plane is referred to as a central plane Poc.

The driving rollers (nip rollers) R2 and R3 are disposed at a predetermined interval along the conveyance direction (+ X direction) of the substrate P, and provide a predetermined amount of slack (margin) to the substrate P after exposure. The drive rollers R2 and R3 rotate while holding both the front and back surfaces of the substrate P, and convey the substrate P toward the manufacturing apparatus PR2, similarly to the drive roller R1. The tension adjusting rollers RT1 and RT2 are pressed in the-Z direction, and apply a predetermined tension to the substrate P wound around the drum DR and supported in the longitudinal direction. Thereby, the tension in the longitudinal direction applied to the substrate P wound around the drum DR is stabilized within a predetermined range. The controller 18 controls a rotation driving source (e.g., a motor, a reduction mechanism, or the like), not shown, to rotate the driving rollers R1 to R3. The rotation axes of the drive rollers R1 to R3 and the rotation axes of the tension adjustment rollers RT1 and RT2 are parallel to the central axis AXo of the drum DR.

The light source device 14 generates and emits a pulse-shaped light beam (pulse light beam, pulsed light, laser light) LB. The light beam LB is ultraviolet light having a peak wavelength in a wavelength band of 370nm or less, and the light emission frequency (oscillation frequency, predetermined frequency) of the light beam LB is Fa. The light beam LB emitted from the light source device 14 enters the drawing head 16 through the beam switching unit BDU. The light source device 14 emits and emits a light beam LB at a light emission frequency Fa in accordance with the control of the control device 18. The light source device 14 may be configured by a semiconductor laser element that generates pulsed light in an infrared wavelength range, an optical fiber amplifier, a wavelength conversion element (harmonic generation element) that converts the amplified pulsed light in the infrared wavelength range into pulsed light in an ultraviolet wavelength range, and the like. By configuring the light source device 14 in this manner, it is possible to obtain high-brightness ultraviolet pulsed light having an oscillation frequency Fa of several hundreds MHz and a light emission time of 1 pulsed light of about picoseconds (picoseconds). The light beam LB emitted from the light source device 14 is made parallel. In embodiment 1, a light source device as shown in japanese patent application laid-open No. 2015-210437 (see fig. 17) is used as the light source device 14. The light beam LB emitted from the light source device 14 is P-polarized light which is linearly polarized light.

The beam switching unit BDU causes the light beam LB to enter any one of the plurality of scanning units Un (where n is 1, 2, … …, or 6) constituting the drawing head 16, and switches the scanning unit Un on which the light beam LB enters. The beam switching unit BDU sequentially switches the scanning unit Un into which the beam LB is incident among the scanning units U1 to U6. That is, the light beam lb (lbn) is time-divisionally distributed to each scanning unit Un. For example, the beam switching section BDU switches the scanning unit Un, into which the light beam LB is incident, in the order of U1 → U2 → U3 → U4 → U5 → U6. Note that LBn may be the light beam LB from the light source device 14 that enters the scanning unit Un through the light beam switching portion BDU. Also, there is a case where the light beam LBn incident to the scanning unit U1 is denoted by LB1 and the light beam LBn incident to the scanning units U2 to U6 is denoted by LB2 to LB6 as well.

The beam switching unit BDU switches the scanning unit Un on which the light beam LBn enters so that the light beam LB enters the scanning unit Un that scans the spot SP. Further, the scanning unit Un performing scanning of the spot SP is switched in the order of U1 → U2 → U3 → U4 → U5 → U6.

The drawing head 16 is a so-called multi-scan type drawing head in which a plurality of scanning units Un (U1 to U6) having the same configuration are arranged. The drawing head 16 draws a pattern on a part of the substrate P supported by the outer circumferential surface (circumferential surface) of the drum DR by a plurality of scanning units Un (U1 to U6). Each of the scanning units Un (U1 to U6) condenses (converges) the light beam LBn on the substrate P while projecting the light beam LBn from the beam switching unit BDU onto the substrate P (onto the irradiated surface of the substrate P). Thereby, the light beam LBn (LB1 to LB6) projected onto the substrate P becomes the spot SP. Each of the scanning units Un (U1 to U6) includes a polygon mirror PM, and scans a spot SP of a light beam LBn (LB1 to LB6) projected onto the substrate P in a main scanning direction (Y direction) using the rotating polygon mirror PM. By scanning the spot SP, a linear drawing line (scanning line) SLn (n is 1, 2, … …, or 6) for drawing a pattern of 1 line is defined on the substrate P. That is, the drawing line SLn indicates the scanning locus of the spot SP of the light beam LBn on the substrate P.

The scanning unit U1 scans the spot SP along the scanning line SL1, and similarly, the scanning units U2 to U6 scan the spot SP along the scanning lines SL2 to SL 6. As shown in fig. 2 and 3, the drawing lines SLn (SL1 to SL6) of the plurality of scanning units Un (U1 to U6) are arranged in 2 rows in the circumferential direction of the drum DR with the center plane Poc (see fig. 1 and 3) therebetween. The odd-numbered drawing lines SL1, SL3, and SL5 are located on the irradiated surface of the substrate P on the upstream side (on the (-X direction side) in the substrate P conveyance direction with respect to the center plane Poc, and are arranged in 1 line at predetermined intervals along the Y direction. The even drawing lines SL2, SL4, and SL6 are located on the irradiated surface of the substrate P on the downstream side (+ X direction side) of the center plane Poc in the conveyance direction of the substrate P, and are arranged in 1 line at predetermined intervals along the Y direction.

Therefore, the plurality of scanning units Un (U1 to U6) are also arranged in 2 rows in the conveyance direction of the substrate P with the center plane Poc therebetween (see fig. 2). That is, the odd-numbered scan units U1, U3, and U5 are disposed upstream (on the (-X direction side) in the conveyance direction of the substrate P with respect to the center plane Poc, and are disposed in 1 row at predetermined intervals along the Y direction. The even-numbered scan units U2, U4, and U6 are disposed on the downstream side (+ X direction side) of the center plane Poc in the conveyance direction of the substrate P, and are disposed in 1 row at predetermined intervals along the Y direction. The odd-numbered scan cells U1, U3, and U5 and the even-numbered scan cells U2, U4, and U6 are disposed symmetrically with respect to the center plane Poc when viewed from the XZ plane.

The odd-numbered drawing lines SL1, SL3, and SL5 and the even-numbered drawing lines SL2, SL4, and SL6 are spaced from each other in the X direction, but are set so as to be in contact with each other without being separated from each other in the Y direction (the width direction of the substrate P and the main scanning direction). The drawing lines SL1 to SL6 are substantially parallel to the width direction (Y direction) of the substrate P, that is, the central axis AXo of the drum DR. The term "the drawing lines SLn are in contact with each other in the Y direction" means that the ends of the respective drawn patterns passing through the drawing lines SLn are adjacent to each other in the Y direction or partially overlap each other. When the ends of the patterns drawn by the drawing lines SLn are overlapped with each other, it is preferable to overlap the ends in the Y direction in a range of several% or less including the drawing start point or the drawing end point with respect to the length of each drawing line SLn, for example.

In this way, each of the scanning units Un (U1 to U6) shares the scanning area so that all of the plurality of scanning units Un (U1 to U6) cover the entire width direction of the exposure area W. Thus, each of the scanning units Un (U1 to U6) can draw a pattern for each of a plurality of regions (drawing ranges) divided in the width direction of the substrate P. For example, if the Y-direction scanning length (the length of the drawing line SLn) of 1 scan cell Un is set to about 20 to 60mm, the Y-direction width that can be drawn is extended to about 120 to 360mm by arranging 3 odd-numbered scan cells U1, U3, and U5 and 3 even-numbered scan cells U2, U4, and U6, and 6 scan cells Un in total, in the Y direction. The lengths (the lengths of the drawing ranges) of the drawing lines SLn (SL1 to SL6) are basically the same. That is, the scanning distances of the spot SP of the light beam LBn scanned along the scanning lines SL1 to SL6 are set to be the same in principle.

In the case of the present embodiment, since the light beam LB from the light source device 14 is a pulsed light, the spot SP projected on the scanning line SLn during the main scanning is dispersed according to the oscillation frequency Fa (for example, 100MHz) of the light beam LB. Therefore, it is necessary to make the spot SP projected by the 1 pulse light of the beam LB and the spot SP projected by the next 1 pulse light mainThe scanning directions overlap. The amount of overlap is set in accordance with the size φ of the spot SP, the scanning speed (speed of main scanning) Vs of the spot SP, and the oscillation frequency Fa of the light beam LB. The effective size phi of the spot SP is 1/e of the peak intensity of the spot SP when the intensity distribution of the spot SP is approximate to a Gaussian distribution²(or 1/2) a decision. In the present embodiment, the scanning speed Vs and the oscillation frequency Fa of the spot SP are set so that the spot SP overlaps with the effective size (dimension) Φ × 1/2. Therefore, the projection interval of the spot SP in the main scanning direction becomes Φ/2. Therefore, it is preferable to set the rotation speed of the drum DR so that the substrate P moves in the circumferential direction by a distance of approximately 1/2, which is the effective size Φ of the spot SP, between 1 scan of the spot SP along the scanning line SLn and the next scan in the sub-scanning direction (the direction orthogonal to the scanning line SLn). Further, when the adjacent drawing lines SLn in the Y direction are connected in the main scanning direction, it is also preferable that they overlap each other by Φ/2. In the present embodiment, the size (dimension) φ of the spot SP is set to 3 μm.

Each of the scanning units Un (U1 to U6) projects each light beam LBn toward the substrate P on at least the XZ plane in such a manner that each light beam LBn advances toward the central axis AXo of the drum DR. Thus, the optical path (beam center axis) of the light beam LBn that advances from each scanning unit Un (U1 to U6) toward the substrate P is parallel to the normal line of the irradiated surface of the substrate P on the XZ plane. At this time, the optical axes (central axes) of the light beams LB1, LB3, LB5 projected toward the substrate P from the odd-numbered scan cells U1, U3, U5 are in the same direction on the XZ plane and overlap with the following orientation line Lx2 (see fig. 1). The optical axes (central axes) of the light beams LB2, LB4, and LB6 projected toward the substrate P from the even-numbered scan cells U2, U4, and U6 are in the same direction on the XZ plane, and overlap with the following orientation line Lx3 (see fig. 1). The azimuth line Lx2 and the azimuth line Lx3 are set so that an angle of ± θ 1 with respect to the center plane Poc on the XZ plane (see fig. 1). That is, on the XZ plane, the traveling direction of the light beam LB projected toward the substrate P from the odd-numbered scan units U1, U3, and U5 and the traveling direction of the light beam projected toward the substrate P from the even-numbered scan units U2, U4, and U6 are symmetrical with respect to the center plane Poc. Each of the scanning units Un (U1 to U6) irradiates the substrate P with the light beam LBn such that the light beam LBn irradiated to the drawing line SLn (SL1 to SL6) is perpendicular to the irradiated surface of the substrate P in a plane parallel to the YZ plane. That is, the light beam LBn (LB1 to LB6) projected onto the substrate P is scanned in the main scanning direction of the spot SP on the irradiated surface in a telecentric state.

The alignment microscopes AMm (AM1 to AM4) shown in fig. 1 are for detecting the alignment marks MKm (MK1 to MK4) formed on the substrate P shown in fig. 3, and are provided in plural numbers (4 in the present embodiment 1) along the Y direction. The plurality of marks MKm (MK1 to MK4) are reference marks for aligning (aligning) a predetermined pattern of the exposure field W drawn on the irradiated surface of the substrate P with respect to the substrate P. The alignment microscopes AMm (AM1 to AM4) detect the marks MKm (MK1 to MK4) on the substrate P supported by the outer peripheral surface (circumferential surface) of the drum DR. The alignment microscopes AMm (AM1 to AM4) are provided on the upstream side (the (-X direction side) in the substrate P conveyance direction of the irradiation region (the region surrounded by the drawing lines SL1 to SL6) on the substrate P from the light spot SP of the light beam LBn (LB1 to LB6) from the drawing head 16.

The alignment microscope AMm (AM1 to AM4) has: a light source that projects illumination light for alignment onto the substrate P; an observation optical system (including an objective lens) that obtains a magnified image of a local region (observation region) Vwm (Vw1 to Vw4) including the mark MKm on the surface of the substrate P; and an image pickup device such as a CCD or a CMOS, which picks up the enlarged image with a high-speed shutter corresponding to the conveyance speed Vt of the substrate P while the substrate P is moving in the conveyance direction. The imaging signals (image data) obtained by the respective imaging of the alignment microscopes AMm (AM1 to AM4) are sent to the control device 18. The controller 18 performs image analysis of the plurality of sent image pickup signals to detect the positions (mark position information) of the marks MKm (MK1 to MK4) on the substrate P. The illumination light for alignment is light in a wavelength region having substantially no sensitivity to the photosensitive functional layer on the substrate P, for example, light having a wavelength of about 500 to 800 nm.

A plurality of marks MK 1-MK 4 are provided around each exposure field W. A plurality of marks MK1, MK4 are formed at regular intervals Dh along the long dimension direction of the substrate P on both sides of the exposure region W in the width direction of the substrate P. Marker MK1 is formed on the-Y direction side of the substrate P in the width direction, and marker MK4 is formed on the + Y direction side of the substrate P in the width direction. The markers MK1 and MK4 are arranged so as to be at the same position in the longitudinal direction (X direction) of the substrate P in a state where the substrate P is not subjected to a large tension or is deformed by heat treatment. Further, marks MK2, MK3 are between mark MK1 and mark MK4, and the blank portions on the + X direction side and the-X direction side of exposure region W are formed along the width direction (short dimension direction) of substrate P. Marker MK2 is formed on the-Y direction side of the substrate P in the width direction, and marker MK3 is formed on the + Y direction side of the substrate P.

Further, the distance between mark MK1 arranged at the end of substrate P on the-Y direction side and mark MK2 in the Y direction, the distance between mark MK2 in the Y direction and mark MK3 in the Y direction, and the distance between mark MK4 arranged at the end of substrate P on the + Y direction side and mark MK3 in the Y direction are all set to the same distance. The marks MKm (MK1 MK4) may be formed together during the formation of the layer 1 pattern layer. For example, the pattern for the mark MKm may be exposed at the same time around the exposure area W of the exposure pattern when the layer 1 pattern is exposed. Further, the mark MKm may also be formed in the exposure area W. For example, it may also be formed within the exposure area W and along the profile of the exposure area W. Further, a pattern portion at a predetermined position or a portion having a predetermined shape in the pattern of the electronic component formed in the exposure region W may be used as the mark MKm.

As shown in fig. 3, the alignment microscope AM1 is arranged to capture an image of the marker MK1 present in the observation region (detection region) Vw1 of the objective lens. Similarly, alignment microscopes AM2 to AM4 are arranged to capture images of markers MK2 to MK4 existing in observation regions Vw2 to Vw4 of the objective lens. Therefore, the alignment microscopes AM1 to AM4 are provided in the order of AM1 to AM4 along the width direction of the substrate P from the-Y direction side of the substrate P in accordance with the positions of the markers MK1 to MK 4.

The alignment microscopes AMm (AM1 to AM4) are provided such that the distance between the exposure position (the drawing lines SL1 to SL6) and the observation region Vwm (Vw1 to Vw4) is shorter in the X direction than the length of the exposure region W in the X direction. The number of alignment microscopes AMm provided in the Y direction may be changed according to the number of marks MKm formed in the width direction of the substrate P. The size of the observation regions Vwm (Vw1 to Vw4) on the irradiated surface of the substrate P is set according to the size of the marks MK1 to MK4 or the alignment accuracy (position measurement accuracy), and is about 100 to 500 μm square.

In embodiment 1, since the drawing lines SL1, SL3, and SL5 of the odd-numbered scan cells U1, U3, and U5 and the drawing lines SL2, SL4, and SL6 of the even-numbered scan cells U2, U4, and U6 are positioned close to each other on the substrate P in the X direction, a plurality of alignment microscopes AM (AM1 to AM4) are arranged on the upstream side of the drawing lines SL1, SL3, and SL 5. However, when the drawing lines SL1, SL3, and SL5 of the odd-numbered scan cells U1, U3, and U5 and the drawing lines SL2, SL4, and SL6 of the even-numbered scan cells U2, U4, and U6 are spaced apart by a predetermined distance or more in the circumferential direction on the substrate P, a plurality of alignment microscopes AMm (AM1 to AM4) may be provided corresponding to the odd-numbered scan cells U1, U3, and U5 and the even-numbered scan cells U2, U4, and U6 arranged along the X direction (the conveying direction of the substrate P). That is, in the X direction, the plurality of alignment microscopes AM (AM1 to AM4) are arranged in 1 row along the Y direction at the same position on the upstream side of the odd-numbered drawing lines SL1, SL3, SL5, and in the X direction, the plurality of alignment microscopes AM (AM1 to AM4) are arranged in 1 row along the Y direction at the downstream side of the even-numbered drawing lines SL1, SL3, SL5 and at the same position on the upstream side of the drawing lines SL2, SL4, SL 6.

As shown in fig. 2, scale portions SDa, SDb having scales formed in a ring shape over the entire circumferential direction of the outer circumferential surface of the drum DR are provided at both end portions of the drum DR. The scale portions SDa and SDb are diffraction gratings in which concave or convex grating lines (scale marks) are formed at a constant pitch (for example, 20 μm) in the circumferential direction of the outer peripheral surface of the drum DR, and are formed as incremental scales. The scales SDa, SDb rotate integrally with the drum DR about the central shaft AXo. The encoder heads EN1a to EN3a and EN1b to EN3b as scale heads for reading the scale sections SDa and SDb are provided so as to face the scale sections SDa and SDb (see fig. 1 and 2).

The encoder heads ENja and ENjb optically detect the rotational angle position of the drum DR by projecting measuring light beams on the scale portions SDa and SDb, respectively. Opposite to the scale portion SDa provided at the end on the-Y direction side of the drum DR, 3 encoder heads ENja (EN1a, EN2a, EN3a) are provided. Similarly, 3 encoder heads ENjb (EN1b, EN2b, EN3b) are provided so as to face the scale portion SDb provided at the end of the drum DR on the + Y direction side.

The encoder heads EN1a and EN1b are provided upstream (on the (-X direction side) in the conveyance direction of the substrate P with respect to the center plane Poc, and are arranged on the azimuth line Lx1 (see fig. 1 and 2). The azimuth line Lx1 is a line connecting the projection positions (reading positions) of the measuring light beams from the encoder heads EN1a and EN1b on the scales SDa and SDb and the central axis AXo on the XZ plane. The line of orientation Lx1 is a line connecting the observation region Vwm (Vw1 to Vw4) of each alignment microscope AMm (AM1 to AM4) and the central axis AXo on the XZ plane. That is, the alignment microscopes AMm (AM1 to AM4) are also disposed on the azimuth line Lx 1.

The encoder heads EN2a, EN2b are provided upstream (on the (-X direction side) in the substrate P conveyance direction with respect to the center plane Poc, and are provided on the downstream side (on the + X direction side) in the substrate P conveyance direction with respect to the encoder heads EN1a, EN1 b. The encoder heads EN2a and EN2b are disposed on the azimuth line Lx2 (see fig. 1 and 2). The azimuth line Lx2 is a line connecting the projection positions (reading positions) of the measuring light beams from the encoder heads EN2a and EN2b on the scales SDa and SDb and the central axis AXo on the XZ plane.

The encoder heads EN3a and EN3b are provided on the downstream side (+ X direction side) of the center plane Poc in the conveyance direction of the substrate P, and are arranged on the azimuth line Lx3 (see fig. 1 and 2). The azimuth line Lx3 is a line connecting the projection positions (reading positions) of the measuring light beams from the encoder heads EN3a and EN3b on the scales SDa and SDb and the central axis AXo on the XZ plane.

When the plurality of alignment microscopes AMm (AM1 to AM4) are arranged in 1 row along the Y direction in correspondence with the even-numbered scanning units U2, U4, and U6, the encoder heads EN4a and EN4b are separately provided on the azimuth line Lx4 on which the plurality of alignment microscopes AMm (AM1 to AM4) are provided. In this case, the alignment microscopes AMm (AM1 to AM4) and the encoder heads EN4a and EN4b are disposed between the odd-numbered scan cells U1, U3, and U5 and the even-numbered scan cells U2, U4, and U6. Note that, of course, the azimuth line Lx4 is a line passing through the central axis AXo.

The encoder heads ENja (EN1a to EN3a) and ENjb (EN1b to EN3b) project the measuring light beams toward the scale parts SDa and SDb and photoelectrically detect the reflected light beams (diffracted light), thereby outputting detection signals (two-phase signals) as pulse signals to the control device 18. The controller 18 interpolates the detection signals (biphase signals) of the encoder heads ENja (EN1a to EN3a) and counts the moving amounts of the lattices of the scale sections SDa and SDb by a digital counter, thereby measuring the rotation angle position and the angular change of the drum DR with a resolution of submicron. The conveyance speed Vt of the substrate P can also be measured based on the change in the angle of the drum DR, that is, the frequency (or cycle) of the pulse signal counted by the digital counter.

Any one of the digital count values based on the detection signals (two-phase signals) from each of the encoder heads EN1a, EN1b or an average value thereof is used as the rotational angle position of the drum DR observed on the free line Lx 1. Likewise, any one or the average of the numerical count values based on each of the encoder heads EN2a, EN2b is used as the rotational angle position of the drum DR viewed from the position line of orientation Lx2, and any one or the average of the numerical count values based on each of the encoder heads EN3a, EN3b is used as the rotational angle position of the drum DR viewed from the position line of orientation Lx 3. Note that, in principle, the numerical count values based on the encoder heads EN1a and EN1b are the same except that the drum DR eccentrically rotates with respect to the central axis AXo due to a manufacturing error or the like of the drum DR. In the same manner, the numerical count values based on each of the encoder heads EN2a, EN2b are also set to be the same, and the numerical count values based on each of the encoder heads EN3a, EN3b are also set to be the same.

By using the alignment system constituted by the plurality of alignment microscopes AMm (AM1 to AM4), the scale sections SDa and SDb, and the plurality of encoder heads ENja (EN1a to EN3a) and ENjb (EN1b to EN3b), the conveyance state (whether or not the substrate P is skewed), the position of the exposure region W, the positions of the drawing lines SL1 to SL6 on the substrate P, and the like can be grasped with high accuracy. As described above, a configuration in which the plurality of encoder heads ENja (EN1a to EN3a) and ENjb (EN1b to EN3b) are arranged around the scale portions SDa and SDb formed annularly along the cylindrical surface is disclosed in, for example, international publication No. 2013/146184.

Next, the configuration of the beam switching unit BDU will be briefly described with reference to fig. 4. The beam switching unit BDU includes a plurality of optical elements for selection AOMn (AOM1 to AOM6), a plurality of mirrors M1 to M3, a plurality of incidence mirrors IMn (IM1 to IM6), and an absorber TR, as described in detail in, for example, international publication No. 2015/166910. The optical selection elements AOMn (AOM 1-AOM 6) are Acousto-Optic modulators (AOM: Acousto-Optic modulators) that are transparent to the light beam LB and are driven by ultrasonic signals. The plurality of optical elements for selection AOMn (AOM1 to AOM6) and the plurality of incidence mirrors IMn (IM1 to IM6) are provided in correspondence with the plurality of scanning units Un (U1 to U6). For example, the selective optical element AOM1 and the incidence mirror IM1 are provided corresponding to the scanning unit U1, and similarly, the selective optical elements AOM2 to AOM6 and the incidence mirrors IM2 to IM6 are provided corresponding to the scanning units U2 to U6, respectively.

The light beam LB from the light source device 14 is guided to the absorber TR with its optical path bent by the mirrors M1 to M3. Hereinafter, the selective optical elements AOMn (AOM1 to AOM6) are all in an off state (a state where no ultrasonic signal is applied) and will be described in detail.

The light beam LB from the light source device 14 advances in the + X direction parallel to the X axis and is incident on the mirror M1. The light beam LB reflected by the mirror M1 in the + Y direction passes through the selective optical elements AOM1, AOM3, and AOM5 in this order, and then reaches the mirror M2. The light beam LB reflected in the + X direction by the mirror M2 is incident on the mirror M3. The light beam LB reflected by the mirror M3 in the-Y direction passes through the optical selection elements AOM2, AOM4, and AOM6 in this order and is then guided to the absorber TR. The absorber TR is a light trap that absorbs the light beam LB to suppress leakage of the light beam LB to the outside.

When an ultrasonic signal (high-frequency signal) is applied to each optical selection element AOMn, 1-order diffracted light, which is obtained by diffracting an incident light beam (0-order light) LB at a diffraction angle corresponding to a frequency of a high frequency, is generated as an output light beam (light beam LBn). Therefore, the light beam emitted as 1-time diffracted light from the optical element for selection AOM1 becomes LB1, and similarly, the light beams emitted as 1-time diffracted light from the optical elements for selection AOMs 2 to AOM6 become LB2 to LB 6. In this manner, each of the selective optical elements AOMn (AOM1 to AOM6) functions to deflect the optical path of the light beam LB from the light source device 14. However, since the actual generation efficiency of the 1 st-order diffracted light by the acousto-optic modulation element is about 80% of that of the 0 th-order light, the intensity of the light beam LBn (LB1 to LB6) deflected by each of the selective optical elements AOMn (AOM1 to AOM6) is lower than that of the original light beam LB. When any of the selective optical elements AOMn (AOM1 to AOM6) is in an on state, approximately 20% of 0 th-order light that travels straight without being diffracted remains, but is finally absorbed by the absorber TR.

The light beam LBn (LB1 to LB6) which is 1-order diffracted light deflected by the selective optical elements AOMn (AOM1 to AOM6) is projected to the corresponding incidence mirrors IMn (IM1 to IM 6). The incidence mirrors IMn (IM1 to IM6) are light guide members that guide the incident light beams LBn (LB1 to LB6) to the corresponding scanning units Un (U1 to U6). For example, the light beam LB1 deflected by the selective optical element AOM1 is incident on the incidence mirror IM1 and then guided to the scanning unit U1.

The respective optical elements AOMn for selection (AOM 1-AOM 6) can have the same constitution, function, action and the like. The plurality of optical elements AOMn for selection (AOM1 to AOM6) turn on/off the generation of diffracted light obtained by diffracting the incident light beam LB in accordance with the on/off of a drive signal (high frequency signal) from the control device 18. For example, when the selection optical element AOM1 is turned off without a drive signal (high-frequency signal) from the control device 18 being applied thereto, the incident light beam LB from the light source device 14 is transmitted without being diffracted. Therefore, the light beam LB transmitted through the selective optical element AOM1 is incident on the selective optical element AOM 3. On the other hand, when the selection optical element AOM1 is turned on by a drive signal (high-frequency signal) from the control device 18, it diffracts the incident light beam LB toward the incident mirror IM 1. That is, the optical element AOM1 for selection is switched on in accordance with the drive signal. In this manner, by switching on any one of the plurality of optical elements for selection AOMn (AOM1 to AOM6), the light beam LBn can be guided to any one of the scanning cells Un, and the scanning cell Un on which the light beam LBn is incident can be switched. In embodiment 1, the scanning unit Un into which the light beam LBn is incident is switched in the order of U1 → U2 → U3 → U4 → U5 → U6, and therefore the optical element for selection AOMm switched to be on may be switched in the order of AOM1 → AOM2 → AOM3 → AOM4 → AOM5 → AOM 6. In the example shown in fig. 4, the selection optical element AOM6 is turned on, and the light beam LB6 is incident on the scanning unit U6.

Fig. 5 is a diagram showing a specific configuration around the selective optical element AOMn and the incidence mirror IMn. In principle, since the configurations around the selective optical element AOMn and the incidence mirror IMn are the same, only the configurations around the selective optical element AOM1 and the incidence mirror IM1 will be described.

For the optical element AOM1 for selection, for example, a beam LB of a parallel beam having a minute diameter (1 st diameter) of about 1mm is incident. When a drive signal as a high-frequency signal (ultrasonic signal) is not input (the drive signal is off), the selective optical element AOM1 allows the incident light beam LB to pass through without being diffracted. The transmitted light beam LB passes through the condenser lens G1 and the collimator lens G2a provided on the optical path thereof and enters the rear stage optical element AOM3 for selection. The optical axis (central axis) of the light beam LB passing through the condenser lens G1 and the collimator lens G2a by the selective optical element AOM1 at this time is AXa. The condenser lens G1 condenses the light beam LB transmitted through the optical element AOM1 at the rear focal point located between the condenser lens G1 and the collimator lens G2 a. The collimator lens G2a collimates the beam LB that has been converged by the condenser lens G1 and then diverged into a parallel beam. The diameter of the beam LB collimated by the collimator lens G2a becomes the 1 st diameter. The rear focal point of the condenser lens G1 and the front focal point of the collimator lens G2a are within a predetermined allowable range. The condenser lens G1 and the collimator lens G2a constitute a relay lens system of equal magnification. The front focal point of the condenser lens G1 and the deflection position of the optical selection element AOM1 are within a predetermined allowable range. In fig. 5, fa denotes a distance of a front focal point of the condenser lens G1, and fb denotes a distance of a rear focal point.

On the other hand, in a state where a drive signal as a high-frequency signal is incident, the selection optical element AOM1 generates a beam LB1(1 st-order diffracted light) that deflects the incident beam LB at a diffraction angle corresponding to the frequency of the high-frequency signal. The light beam LB1 deflected in the-Z direction at a diffraction angle corresponding to the frequency of the high-frequency signal passes through the condenser lens G1 and enters an entrance mirror (also referred to as an "epi-mirror" because the light beam is caused to fall in the-Z direction) IM1 provided at a position of the rear focal point of the condenser lens G1 or a position near the rear focal point. The condenser lens G1 bends the light beam LB1 so that the optical axis (central axis) AXb of the light beam LB1 deflected in the-Z direction is parallel to the optical axis AXa of the light beam LB, and condenses (converges) the light beam LB1 on or near the reflection surface of the incidence mirror IM 1. The light beam LB1 reflected in the-Z direction by the incident mirror IM1 provided on the-Z direction side with respect to the light beam LB transmitted through the optical element AOM for selection 1 is incident on the scanning unit U6 via the collimator lens G2 b. The collimator lens G2b makes the back-divergent light beam LB1 condensed by the condenser lens G1 a parallel light beam having the same diameter as the 1 st diameter. The rear focal point of the condenser lens G1 and the front focal point of the collimator lens G2b are within a predetermined allowable range. The condenser lens G1 and the collimator lens G2b constitute a relay lens system of equal magnification.

Next, the structure of the scanning unit (optical beam scanning device) Un will be described with reference to fig. 6 and 7. Since each of the scan units Un (U1 to U6) has the same configuration, only the scan unit U1 will be described in brief. Fig. 6 is a perspective view showing the structure of the scanner unit U1, and fig. 7 is a view of the scanner unit U1 shown in fig. 6 as viewed from the + Y direction. The scanning unit U1 includes a cylindrical lens CY1, a polarization beam splitter PBS, a λ/4 wave plate QP, a polygon mirror (movable reflection member) PM, a cylindrical lens CY2, a mirror M10, an f θ lens FT, a mirror M11, and a cylindrical lens CY 3.

The beam LB1 of the parallel light flux reflected in the-Z direction by the incident mirror (light guide member) IM1 shown in fig. 5 is converted into a parallel light flux having a predetermined diameter (for example, several mm) expanded from the 1 st diameter (for example, about 1 mm) by a beam expander optical system (not shown), and then enters the scanning unit U1 along the optical axis AX1 parallel to the Z axis. The light beam LB1 (hereinafter, sometimes referred to as an incident light beam LB1a) incident to the scanning unit U1 is incident to the polarization beam splitter PBS through a cylindrical lens (2 nd optical member) CY1 having a generatrix in the Y direction provided on the optical axis AX 1. The polarization splitting plane Qs of the polarization beam splitter PBS is inclined at 45 degrees with respect to the XY plane, transmits the P-polarized light, and reflects the linearly polarized light (S-polarized light) polarized in the direction orthogonal to the P-polarized light. Since the light beam LB emitted from the light source device 14 is P-polarized light, the light incident on the polarization beam splitter PBS through the cylindrical lens CY1 passes through the polarization beam splitter PBS along the optical axis AX1, passes through the λ/4 wave plate QP provided on the-Z direction side of the polarization beam splitter PBS, and is then guided to the reflection surface RP of the polygon mirror PM. Further, the polarization beam splitter PBS and the λ/4 wave plate QP constitute a beam splitting means.

The polygon mirror PM is a rotary polygon mirror having a rotation shaft AXp and a plurality of reflection surfaces RP formed around the rotation shaft AXp in parallel with the rotation shaft AXp (in the present embodiment 1, the number Np of the reflection surfaces RP is 8). The polygon mirror PM is disposed such that a plane orthogonal to the rotation axis AXp is inclined at 45 degrees with respect to the XY plane so that an incident light flux LB1a incident from the polarizing beam splitter PBS onto the reflection surface RP of the polygon mirror PM is reflected toward the mirror M10 disposed at a position on the-X direction side of the polygon mirror PM. The polygon mirror PM rotates about the rotation axis AXp to scan the spot SP of the beam LB1 on the surface of the substrate P to be irradiated. The reflection angle of the pulse-shaped light beam LB1a irradiated on the reflection surface RP can be continuously changed by rotating the polygon mirror PM in a predetermined rotation direction about the rotation axis AXp. Thus, the light beam LB1 can be deflected by 1 reflection surface RP, and the spot SP of the light beam LB1 irradiated on the irradiated surface of the substrate P can be scanned in the main scanning direction (the width direction and the Y direction of the substrate P). Therefore, when the polygon mirror PM rotates once, the number of times of scanning the spot SP along the scanning line SL1 on the surface to be irradiated of the substrate P becomes 8 times at the maximum, which is the same as the number of the reflection surfaces RP. The polygon mirror PM is rotated at a fixed speed by a rotation drive source RM1 (see fig. 10) such as a motor under the control of the control device 18.

The polygon mirror PM deflects the incident beam LB1a incident from the polarizing beam splitter PBS in a plane parallel to the XY plane including the optical axis AX2 set parallel to the X axis, and also deflects the incident beam in the Y direction around the optical axis AX 2. The generatrix of the cylindrical lens CY1 extending in the Y direction is located on the plane (plane parallel to the XY plane) in which the incident light beam LB1a is polarized. The optical axis AX2 is orthogonal to the optical axis AX1, and a plane containing the optical axes AX1, AX2 and the rotation axis AXp is parallel to the XZ plane.

The cylindrical lens (2 nd optical member) CY1 having a generatrix in the Y direction converges the incident light flux LB1 on the reflection surface RP of the polygon mirror PM in the non-scanning direction (Z direction or direction of the rotation axis AXp) orthogonal to the main scanning direction (rotation direction, deflection direction) by the polygon mirror PM. That is, the cylindrical lens CY1 converges the light beam LB1 on the reflection surface RP into a slit shape (oblong shape) extending in the Y direction. Further, the cylindrical lens CY1 having a generatrix in the Y direction transmits the incident light flux LB1a as parallel light without converging in the main scanning direction (deflecting direction) by the polygon mirror PM.

The reflected light of the incident light beam LB1a reflected toward the-X direction side by the reflection surface RP of the polygon mirror PM (hereinafter, sometimes referred to as a 1 st reflected light beam LB1b) is incident on the reflection mirror M10 through the cylindrical lens (1 st optical member) CY 2. The 1 st reflected light beam LB1b reflected on the reflection surface RP is incident on the cylindrical lens CY2 while diverging in a non-scanning direction (Z direction) orthogonal to the main scanning direction by the polygon mirror PM, and becomes parallel light by the cylindrical lens CY2 having a generatrix in the Y direction. Therefore, the 1 st reflected light beam LB1b to be incident to the mirror M10 becomes a parallel light beam of substantially the same diameter as the incident light beam LB1a to be incident to the cylindrical lens CY 1. Further, the rear focal point of the cylindrical lens CY1 and the front focal point of the cylindrical lens CY2 coincide within a predetermined allowable range on the reflection surface RP of the polygon mirror PM on which the incident light beam LB1a is incident.

The reflection mirror M10 reflects the 1 st reflected light beam LB1b, which was originally reflected by the reflection surface RP of the polygon mirror PM, again toward the reflection surface RP of the polygon mirror PM. The reflected light of the 1 st reflected light beam LB1b (hereinafter, sometimes referred to as the 2 nd reflected light beam LB1c) reflected by the mirror M10 is incident on the reflection surface RP that initially reflects the incident light beam LB1 a. Hereinafter, for ease of understanding of the description, the reflection surface RP of the polygon mirror PM on which the incident light beam LB1a transmitted through the polarization beam splitter PBS enters is denoted by RPa. Therefore, the reflection surface RP that reflects the 1 st reflected light beam LB1b toward the mirror M10 becomes the reflection surface RPa together with the reflection surface RP on which the 2 nd reflected light beam LB1c reflected by the mirror M10 enters. The 2 nd reflected light beam LB1c reflected by the mirror M10 passes through the cylindrical lens CY2 and enters the reflection surface RPa. Therefore, the 2 nd reflected light beam LB1c that has again entered the reflection surface RPa converges on the reflection surface RPa in the non-scanning direction (the Z direction or the direction of the rotation axis AXp) orthogonal to the main scanning direction (the deflection direction) by the polygon mirror PM by the cylindrical lens CY 2. That is, the cylindrical lens CY2 converges the 2 nd reflected light beam LB1c on the reflection surface RPa into a slit shape (oblong shape) extending in the Y direction. In a non-scanning direction (direction of the Z direction or the rotation axis AXp) orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM, the converging position on the reflection surface RPa by the cylindrical lens CY1 and the converging position on the reflection surface RPa by the cylindrical lens CY2 are set to the same position. That is, in the non-scanning direction (the Z direction or the direction of the rotation axis AXp) orthogonal to the main scanning direction (the deflection direction) by the polygon mirror PM, the position of the incident light beam LB1a that is first incident on the reflection surface RPa and the position of the 2 nd reflected light beam LB1c that is incident again (2 nd time) are set to substantially the same position. Thereby, the thickness (length in the direction of the rotation axis AXp) of the polygon mirror PM can be made thin. Further, the cylindrical lenses CY1 and CY2 whose generatrices are parallel to the Y direction and the cylindrical lens CY3 described below can suppress the influence of the reflection surface RPa even when the reflection surface RPa is inclined with respect to the direction of the rotation axis AXp. For example, the irradiation position of the spot SP (the drawing line SL1) of the light beam LB1 irradiated onto the irradiated surface of the substrate P can be suppressed from being shifted in the X direction due to a slight inclination error of each of the reflecting surfaces RP of the polygon mirror PM. Further, the mirror M10 and the cylindrical lens CY2 constitute a re-reflection optical system.

The reflection surface RPa of the polygon mirror PM reflects the 2 nd reflected light beam LB1c reflected by the mirror M10 toward the + Z direction side. The polygon mirror PM deflects the 2 nd reflected light beam LB1c incident from the reflection mirror M10 in a plane including the optical axis AX1 parallel to the Z axis and parallel to the YZ plane. The reflected light of the 2 nd reflected light beam LB1c reflected again by the reflection surface RPa of the polygon mirror PM (hereinafter, sometimes referred to as the 3 rd reflected light beam LB1d) is incident again on the polarization beam splitter PBS. Here, since the λ/4 wave plate QP is provided between the polygon mirror PM and the polarization beam splitter PBS, the light beam LB1a transmitted through the polarization beam splitter PBS and incident on the reflection surface RPa of the polygon mirror PM is converted from P-polarized light to circularly polarized light. The light beam LB1d reflected by the reflection surface RPa of the polygon mirror PM and again incident on the polarization beam splitter PBS is converted from circularly polarized light to S polarized light. Therefore, the 3 rd reflected light beam LB1d is reflected toward the + X direction side by the polarization splitting plane Qs of the polarization beam splitter PBS inclined by 45 degrees with respect to the XY plane.

The 3 rd reflected light beam LB1d reflected to the + X direction side by the polarization separation plane Qs is incident on the f θ lens FT having an optical axis AXf parallel to the X axis. The f θ lens FT is a scanning lens of a telecentric system that projects the 3 rd reflected light beam LB1d reflected by the polygon mirror PM onto the mirror M11 (eventually, the substrate P) in parallel with the optical axis AXf in a plane including the optical axis AXf and parallel with the XY plane. The f θ lens FT scans the 3 rd reflected light beam LB1d projected to the mirror M11 (eventually, the substrate P) with the optical axis AXf as the center in the Y direction. The incident angle θ of the light beam LB1 to the f θ lens FT varies according to the rotation angle (θ/4) of the polygon mirror PM. The f θ lens FT projects the light beam LB1(LB1d) to an image height position on the irradiated surface of the substrate P in proportion to the incident angle θ via the mirror M11 and the cylindrical lens CY 3. When the focal length is fo and the image height position is y, the f θ lens FT is designed so as to satisfy the relationship (distortion aberration) of y ═ fo × θ. Therefore, the f θ lens FT can accurately scan the light beam LB1 at a constant speed in the Y direction. A plane including the optical axes AX1, AX2, and AXf is parallel to the XZ plane, and when the incident angle θ to the f θ lens FT is 0 degree, the principal ray of the light beam LB1(LB1d) incident on the f θ lens FT advances along the optical axis AXf.

In embodiment 1, since the light beam LB1 is reflected twice on the reflection surface RPa of the polygon mirror PM, the incident angle θ of the light beam LB1 on the f θ lens FT is 4 times the rotation angle of the polygon mirror PM. However, when the light beam LB1 is reflected only 1 time on the reflection surface RPa of the polygon mirror PM, the incident angle θ of the light beam LB1 on the f θ lens FT becomes 2 times the rotation angle of the polygon mirror PM. Therefore, the scanning speed of the spot SP can be set to 2 times by reflecting the light beam LB1 twice on the reflection surface RPa of the polygon mirror PM. This will be described in detail below with reference to fig. 8.

The 2 nd reflected light beam LB1c reflected by the mirror M10 and incident on the polygon mirror PM converges on the reflection surface RPa in the non-scanning direction (Z direction) orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM by the cylindrical lens CY 2. Therefore, the 3 rd reflected light beam LB1d reflected by the reflection surface RPa and directed toward the f θ lens FT diverges and enters the f θ lens FT in the non-scanning direction (Z direction) orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM. On the other hand, the 2 nd reflected light beam LB1c reflected by the mirror M10 and incident on the polygon mirror PM becomes parallel light in the main scanning direction (deflecting direction) by the polygon mirror PM. Therefore, the 3 rd reflected light beam LB1d reflected by the reflection surface RPa and directed toward the f θ lens FT becomes a parallel light beam in the main scanning direction (deflection direction) by the polygon mirror PM.

The f θ lens FT makes the 3 rd reflected light beam LB1d, which is incident while diverging, substantially parallel light in a non-scanning direction (Z direction) orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM. The f θ lens FT converges the 3 rd reflected light beam LB1d of the incident parallel light on the substrate P in the main scanning direction (deflecting direction) by the polygon mirror PM. Therefore, the f θ lens FT has a front focal point on the reflection surface RPa of the polygon mirror PM on which the light beam LB (LB1a, LB1c) is incident, and a rear focal point on the substrate P. The light beam LB1d transmitted through the f θ lens FT is bent by the mirror M11, and then passes through a cylindrical lens (3 rd optical member) CY3 having a bus line in the Y direction to reach the substrate P. The mirror M11 reflects the 3 rd reflected light beam LB1d toward the substrate P in the XZ plane in such a manner that the optical axis of the 3 rd reflected light beam LB1d overlaps with the azimuth line Lx2 to advance. The cylindrical lens CY3 converges the 3 rd reflected light beam LB1d of the parallel light transmitted through the f θ lens FT on the substrate P in the non-scanning direction (Z direction) orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM. Therefore, the light beam LB1 projected onto the substrate P is converged to the spot SP on the substrate P by the f θ lens FT and the cylindrical lens CY 3. Further, the rear focal point of the cylindrical lens CY3 is located on the substrate P. The f θ lens FT and the cylindrical lens CY3 constitute a scanning optical system.

In fig. 7, the mirror M11 and the cylindrical lens CY3 are arranged such that the principal ray of the light flux LB1d (or the optical axis AXf of the f θ lens FT) reflected in the-Z direction by the mirror M11 is inclined at an angle θ 1 with respect to the Z axis in a plane parallel to the XZ plane. The angle θ 1 corresponds to a slope angle ± θ 1 of the azimuth line Lx2 (or Lx3) from the central plane Poc shown in fig. 1. Therefore, the reflection surface (plane) of the mirror M11 is arranged obliquely at an angle (45 ° - θ/2) with respect to the XY plane. However, when each of the scanning units Un (U1 to U6) of fig. 6 and 7 is tilted at an angle θ 1 with respect to the entire XY plane from the illustrated state, the reflection surface of the mirror M11 is arranged to intersect the optical axis AXf at 45 ° so as to reflect the principal ray of the light beam LB1d from the f θ lens FT at 90 ° in the XZ plane.

Next, fig. 8 is a description of the reflection angle of the light beam LB1 when reflected 2 times by the reflection surface RPa of the polygon mirror PM. In fig. 8, the arrangement of the polygon mirror PM, the polarization beam splitter PBS, the cylindrical lens CY2, and the reflection mirror M10 is slightly different from that shown in fig. 7 and 8 because the optical path of the light beam LB1 is schematically illustrated to facilitate understanding.

In fig. 8, the amount of angular change of the reflection surface RPa of the polygon mirror PM on which the incident light beam LB1a is incident with respect to the reference surface Po is Δ θ. The reference plane Po is a plane including the rotation axis AXp of the polygon mirror PM and parallel to a plane extending in the Y direction. When the angular change amount Δ θ of the reflection surface RPa with respect to the reference surface Po is 0 degree, the incident beam LB1a incident on the reflection surface RPa of the polygon mirror PM along the optical axis AX1 enters the mirror M10 along the optical axis AX 2. Therefore, in this case, the 2 nd reflected light beam LB1c reflected by the mirror M10 enters the reflection surface RPa of the polygon mirror PM along the optical axis AX2, where the 3 rd reflected light beam LB1d reflected thereon proceeds toward the polarization beam splitter PBS along the optical axis AX1, and thereafter passes through the f θ lens FT on the optical axis AXf. Further, the optical axes AX1, AX2, and AXf are coaxial when viewed on the optical path of the light beam LB 1.

The 1 st reflected light beam LB1b of the incident light beam LB1a transmitted through the cylindrical lens CY1 and the polarization beam splitter PBS and incident on the reflection surface RPa of the polygon mirror PM is reflected toward the mirror M10 at an angle corresponding to the angle change Δ θ. At this time, the amount of change in the incident angle of the 1 st reflected light beam LB1b from the reflection surface RPa toward the mirror M10 with respect to the optical axis AX2 on the XY plane becomes 2 × Δ θ. The 2 nd reflected light beam LB1c reflected by the mirror M10 enters the reflection surface RPa of the polygon mirror PM again, and is then guided to the f θ lens FT via the polarization beam splitter PBS. At this time, the 3 rd reflected light beam LB1d is reflected again at an angle corresponding to the angle change Δ θ and enters the f θ lens FT. Therefore, the amount of change in the incident angle of the 3 rd reflected light beam LB1d with respect to the optical axis AXf of the f θ lens FT on the XY plane is 4 × Δ θ. In this way, the deflection angle of the 1 st reflected light beam LB1b when the light beam LB1a is reflected on the reflection surface RPa of the polygon mirror PM for the 1 st time is 2 times the angular change amount Δ θ of the reflection surface RPa of the polygon mirror PM, and the deflection angle of the 3 rd reflected light beam LB1d (the incident angle to the f θ lens FT) when the reflection surface RP is reflected on the 2 nd time is 4 times the angular change amount Δ θ of the reflection surface RPa. Therefore, when the scanning length of the drawing line SL1 of the spot SP of the scanning beam LB1(LB1d) is fixed, the rotation angle of the polygon mirror PM necessary for effective scanning can be halved when scanning is performed by reflecting the light beam on the reflection surface RPa 2 times, as compared with the case of scanning by reflecting the light beam on the reflection surface RPa 1 time.

Fig. 9 is a diagram illustrating the rotation angle of the polygon mirror PM required for 1 scan. The angle θ m shown in fig. 9 is an angle at which the polygon mirror PM rotates 1 the reflection surface RP. In embodiment 1, since the polygon mirror PM is a rotary polygon mirror having 8 reflection surfaces RP, the angle θ m is 45 degrees (360 degrees/8). While the polygon mirror PM is rotated by the angle θ m, the angle θ w actually contributing to the scanning of the spot SP is smaller than the angle θ m. When the scanning length of the scanning line SL1 is fixed, the angle θ w when the light spot SP is scanned by reflecting the reflection surface RPa 1 time is set to θ w1, and the angle θ w when the light spot SP is scanned by reflecting the reflection surface RPa 2 times is set to θ w 2. Here, the angle θ w1 is set to an angular range in which the light beam (LB1a) reflected 1 time on the reflection surface RPa can pass through the f θ lens FT 1.

As described above, when the light is reflected 1 time on the reflection surface RPa, the incident angle to the f θ lens FT becomes 2 times the angle change amount Δ θ of the reflection surface RPa, and when the light is reflected 2 times on the reflection surface RPa, the change (deflection angle) of the incident angle to the f θ lens FT becomes 4 times the angle change amount Δ θ of the reflection surface RPa, and therefore, the angles θ w1 and θ w2 become 1/2 × θ w1 as θ w 2. Therefore, if the angle θ w1 is set to 15 degrees, for example, the scanning efficiency α 1 of the reflection surface RPa when the reflection surface RPa reflects 1 time and scans the spot SP becomes α 1 — θ w1/θ m — 15 degrees/45 degrees 1/3, and the scanning efficiency α 2 of the reflection surface RPa when the reflection surface RPa reflects 2 times and scans the spot SP becomes α 2 — θ w2/θ m — 7.5 degrees/45 degrees 1/6.

Therefore, while the reflection surface RPa of the polygon mirror PM rotates by 1 reflection surface RP, the scanning unit Un into which the light beam LBn enters can be switched on in the order of, for example, U1 → U2 → U3 → U4 → U5 → U6 by sequentially switching the optical elements for selection AOM1 to AOM6 on. That is, since the rotation angle θ w2 contributing to actual scanning is 7.5 degrees, the rotation angle which does not contribute to actual scanning among the angles (45 °) at which the polygon mirror PM rotates by 1 reflection surface RP reaches 37.5 degrees, and the light beam LBn is not made incident on the polygon mirror PM of the scanning unit U1 during this period, and becomes useless. Therefore, the light beam LBn is selectively switched in the unnecessary period and is incident on the other scanning units U2 to U6 in a time-sharing manner, whereby the light beam LBn can be effectively used. Further, the polygon mirror PM rotates by 45 degrees from the start of scanning of the spot SP by each scanning unit Un (U1 to U6) to the start of the next scanning.

Here, in order for the plurality of scanning units Un to scan the spot SP in the order of, for example, U1 → U2 → U3 → U4 → U5 → U6, the polygon mirror PM of each scanning unit Un (U1 to U6) must be rotated in synchronization, and the rotational angle positions thereof must be in a predetermined phase relationship. Further, it is necessary to switch any of the plurality of selection optical elements AOMn (AOM1 to AOM6) of the beam switching portion BDU to be on, and to cause the beam LBn to enter the scanning cell Un while the scanning cell Un can scan the spot SP. A schematic configuration of a control circuit system provided in the control device 18 shown in fig. 1 to achieve this will be described below with reference to fig. 10.

First, the rotation control of the polygon mirror PM of the plurality of scanning units Un (U1 to U6) will be explained. Origin sensors OPn (OP1 to OP6) are provided in the scanning units Un (U1 to U6). Each of the origin sensors OPn (OP1 to OP6) generates a pulse-shaped origin signal SZn (SZ1 to SZ6) when the rotational position of the reflection surface RP of the polygon mirror PM of the scanning unit Un (U1 to U6) reaches a predetermined position at which scanning of the spot SP passing through the reflection surface RP can be started. In other words, each of the origin sensors OPn (OP1 to OP6) generates the origin signal SZn (SZ1 to SZ6) when the angle of the reflection surface RP to be scanned by the spot SP next becomes a predetermined angular position. Since the polygon mirror PM has 8 reflection surfaces RP, the origin sensor OPn (OP1 to OP6) outputs the origin signal SZn (SZ1 to SZ6) 8 times while the polygon mirror PM of the scanning unit Un (U1 to U6) makes one rotation. The origin signals SZn (SZ1 to SZ6) generated by the origin sensors OPn (OP1 to OP6) are sent to the polygon mirror drive control unit 20 of the control device 18. The origin sensor OPn includes: a beam delivery system opa for emitting a laser beam Bga in a wavelength region not sensitive to the photosensitive functional layer of the substrate P, to the reflection surface RP; and a beam light-receiving system opb that receives a reflected beam Bgb of the laser beam Bga (continuous light emission) reflected by the reflection surface RP and generates an origin signal SZ 1.

The polygon mirror PM of each scanning unit Un (U1 to U6) is rotated about the rotation shaft AXp by driving a rotation drive source RMn (RM1 to RM6) including a motor or the like. The polygon mirror drive control unit 20 controls the rotation of the polygon mirror PM by controlling the rotation drive sources RMn (RM1 to RM6) that rotate the polygon mirror PM of each scanning unit Un (U1 to U6). The polygon mirror drive control unit 20 synchronously rotates the polygon mirrors PM of the plurality of scanning units Un (U1 to U6) such that the rotational angle positions of the polygon mirrors PM of the plurality of scanning units Un (U1 to U6) have a predetermined phase relationship, based on the origin signal SZn (SZ1 to SZ 6). That is, the rotation of the polygon mirror PM of the plurality of scanning units Un (U1 to U6) is controlled such that the rotational speeds (the numbers of rotations) of the polygon mirror PM of the plurality of scanning units Un (U1 to U6) are identical to each other and the phases of the rotational angle positions are shifted by a fixed angle one by one.

Since the angle θ w2 contributing to the actual scanning of the spot SP is 7.5 degrees in the present embodiment, the polygon mirror drive control unit 20 synchronously controls the rotation of the polygon mirror PM of the plurality of scanning units Un (U1 to U6) so as to rotate at a constant speed while shifting the rotational angle positions of the polygon mirror PM of the plurality of scanning units Un (U1 to U6) by 7.5 degrees one by one. In embodiment 1, since the order of the scanning unit Un on which the light beam LBn is incident, that is, the order of the scanning unit Un that scans the spot SP is U1 → U2 → U3 → U4 → U5 → U6, the rotational angle position of the polygon mirror PM in each of the plurality of scanning units Un (U1 to U6) is controlled so as to be shifted by 7.5 degrees one by one in accordance with the order.

Specifically, the polygon mirror drive control section 20 synchronously controls the rotation of the polygon mirror PM of the scanning unit U2 such that the origin signal SZ2 from the origin sensor OP2 of the scanning unit U2 is delayed by the time Ts with reference to the origin signal SZ1 from the origin sensor OP1 of the scanning unit U1. This time Ts is a time required for the polygon mirror PM to rotate 7.5 degrees. The polygon mirror drive control unit 20 synchronously controls the rotation of the polygon mirror PM of the scanning unit U3 so that the origin signal SZ3 from the origin sensor OP3 of the scanning unit U3 is delayed by 2 × time Ts with reference to the origin signal SZ 1. In the same manner, the rotations of the polygon mirrors PM of the scanning units U4 to U6 are synchronously controlled so that the origin signals SZ4, SZ5, and SZ6 are generated with a delay of 3 × time Ts, 4 × time Ts, and 5 × time Ts with the origin signal SZ1 set as a reference. The polygon mirror drive control unit 20 outputs the obtained origin signals SZ1 to Z6 to the AOM drive control unit 22 shown in fig. 10.

Next, the timing when the plurality of optical elements for selection AOMn (AOM1 to AOM6) are switched to on will be described. The AOM drive control unit (beam switching drive control unit) 22 shown in fig. 10 controls the plurality of selection optical elements AOMn (AOM1 to AOM6) of the beam switching unit BDU to sequentially distribute the beam lb (lbn) from the light source device 14 to the 6 scanning units Un (U1 to U6) in time division from the start of scanning of the spot SP by 1 scanning unit Un to the start of the next scanning.

Specifically, when the origin signal SZn is generated (SZ1 to SZ6), the AOM drive control unit 22 applies a drive signal (high frequency signal) HFn (HF1 to HF6) to the optical elements AOMn (AOM1 to AOM6) for selection corresponding to the scanning units Un (U1 to U6) that generate the origin signals SZn (SZ1 to SZ6) from a fixed time (on time Ton) after the origin signal SZn is generated. Thereby, the optical element AOMn for selection to which the driving signal (high-frequency signal) HFn is applied is turned on for the on time Ton, and the light beam LBn can be incident on the corresponding scanning cell Un. Further, since the light beam LBn is incident on the scanning cell Un that generates the origin signal SZn, the light beam LBn can be incident on the scanning cell Un that can scan the spot SP. The on time Ton is a time equal to or shorter than a time Ts during which the polygon mirror PM rotates by 7.5 degrees.

The origin signals SZ 1-SZ 6 generated in the 6 scan cells U1-U6 are generated at intervals of time Ts in the order SZ1 → SZ2 → SZ3 → SZ4 → SZ5 → SZ 6. Therefore, the drive signal (high-frequency signal) HFn is applied to the plurality of optical elements for selection AOM1 to AOM6 at time Ts intervals in the order HF1 → HF2 → HF3 → HF4 → HF5 → HF 6. Therefore, the 1 scanning unit Un into which the light beam LBn from the light source device 14 is incident can be switched at time Ts intervals in the order of U1 → U2 → U3 → U4 → U5 → U6, and the plurality of scanning units Un (U1 to U6) can scan the spot SP in this order.

The light source device 14 has a control circuit 14 a. The control circuit 14a controls a semiconductor laser element, not shown, of the light source device 14 so as to generate a clock signal LTC at an oscillation frequency Fa and emit seed light in response to the clock signal LTC. The seed light in the infrared region emitted from the semiconductor laser element is amplified by the optical fiber amplifier, and the amplified pulse light in the infrared wavelength region is converted into pulse light in the ultraviolet wavelength region by the wavelength conversion element. The converted pulsed light in the ultraviolet wavelength range is output from the light source device 14 as a light beam LB. The light beam LB emitted from the light source device 14 is a light beam LBn whose intensity is adjusted to a high level and a low level in accordance with a pattern of 1 line (1 drawing line SLn) drawn by the scanning unit Un on which the light beam LB (lbn) is incident. For example, while the light beam LBn is incident on the scanning unit U1, the intensity of the light beam LB emitted from the light source device 14 is modulated in intensity according to the pattern of the 1-trace SL1 drawn by the scanning unit U1. The structure of the light source device 14 is disclosed in japanese patent laid-open publication No. 2015-210437. The clock signal LTC generated by the control circuit 14a is output to a polygon mirror drive control unit 20, an AOM drive control unit 22, and a controller 24 provided in the control device 18. The polygon mirror drive control unit 20, the AOM drive control unit 22, and the controller 24 operate in accordance with a clock signal LTC. The controller 24 functions as an overall control unit that controls the polygon mirror drive control unit 20, the AOM drive control unit 22, and the light source device 14. The polygon mirror drive control unit 20 outputs the obtained origin signal SZn (SZ1 to SZ6) to the controller 24, and the controller 24 manages the scanning units Un (U1 to U6) to be scanned by the spot SP next using the origin signal SZn (SZ1 to SZ 6). Then, the controller 24 outputs pattern information of 1 line amount (1 scanning amount of the spot SP) drawn by the scanning unit Un which is to perform scanning of the spot SP next to the light source device 14. The light source device 14 modulates the intensity of the light beam LB emitted based on the pattern information at a high speed with a time resolution corresponding to the period of the clock signal LTC.

In this way, the spot SP of the light beam LBn polarized by reflecting the light beam LBn twice on the reflection surface RPa of the polygon mirror PM is projected onto the substrate P, and therefore, the scanning speed of the spot SP can be increased. Further, since the scanning efficiency of the reflection surface RP of the polygon mirror PM, that is, the rotation angle of the polygon mirror PM contributing to actual scanning can be reduced, the light flux LBn can be time-divisionally distributed to more scanning units Un while the polygon mirror PM rotates 1 reflection surface RP. Further, the positions of the light beam LB1 that is first incident on the reflection surface RPa and the light beam LB1 that is again (2 nd) incident are set to the same position in the non-scanning direction (the Z direction or the direction of the rotation axis AXp) that is orthogonal to the main scanning direction (the deflection direction) by the polygon mirror PM using the cylindrical lenses CY1, CY 2. Thereby, the thickness (length in the direction of the rotation axis AXp) of the polygon mirror PM can be made thin. Therefore, the weight of the polygon mirror PM can be reduced, and the rotation speed of the polygon mirror PM can be increased.

As described with reference to fig. 9, the deflection angle θ w2 when the light beam LBn (LB1d) is scanned by the polygon mirror PM is half, and therefore the scanning efficiency α 1 of 1 reflection surface RPa of the polygon mirror PM is also half 1/6, but when the scanning efficiency α 1 is only 1/3, the angle θ m corresponding to 1 reflection surface RP of the polygon mirror PM can be half, and therefore a polygon mirror of 16 reflection surfaces RP can be used as the polygon mirror PM. Further, in the present embodiment, the description is given taking the reflecting surface of the mirror M10 shown in fig. 6 and 7 as a plane parallel to the YZ plane, but it may be a concave spherical surface having a large radius of curvature or a concave cylindrical surface. By making the reflection surface of the mirror M10 a curved surface, the influence (distortion of the drawn line SLn, etc.) caused by a slight positional change in the Z direction of the reflected light beam LB1b that may occur due to a shift between the reflection surface RP of the polygon mirror PM and the rotation axis AXp can be corrected or alleviated.

[ modification of embodiment 1 ]

The embodiment 1 can be modified as follows.

(modification 1) fig. 11 is a diagram showing the structure of a scanner unit U1a in modification 1. The same components as those in embodiment 1 are denoted by the same reference numerals. In modification 1, 6 scan cells Una (U1a to U6a) having the same configuration as scan cell U1a in fig. 11 are also arranged as shown in fig. 2. Since the plurality of scan cells Una (U1a to U6a) have the same configuration, the scan cell U1a will be described as an example. The scanning unit U1a includes a mirror M12, a cylindrical lens CY1, a polarization beam splitter PBS, a λ/4 wave plate QP, a polygon mirror PM, a cylindrical lens CY2, a mirror M10, an f θ lens FT, and a cylindrical lens CY 3. Further, the polarization beam splitter PBS and the λ/4 wave plate QP constitute a beam splitting means, and the cylindrical lens CY2 and the mirror M10 constitute a re-reflection optical system. The f θ lens FT and the cylindrical lens CY3 constitute a scanning optical system.

A parallel light beam LB1, which is reflected in the-Z direction by an incidence mirror (an epi-mirror as a light guide member) IM1 shown in fig. 5 and expanded to a predetermined diameter, is incident on the scanning unit U1a along an optical axis AX1 parallel to the Z axis. The light beam LB1 (hereinafter, sometimes referred to as an incident light beam LB1a) incident to the scanning unit U1a is reflected in the-X direction along an optical axis AX3 parallel to the X axis by a mirror M12 provided at 45 ° on the optical axis AX 1. The incident light beam LB1a reflected in the-X direction by the mirror M12 enters the reflection surface RPa of the polygon mirror PM through the cylindrical lens CY1 having a generatrix in the Y direction and disposed on the optical axis AX3, the polarization beam splitter PBS, and the λ/4 wave plate QP. Although the description has been given above with respect to embodiment 1, it should be noted that the light beam LB1 is P-polarized light, and the polarization beam splitter PBS transmits P-polarized light and reflects S-polarized light.

The polygon mirror PM is disposed such that a plane orthogonal to the rotation axis AXp of the polygon mirror PM is inclined at a slight angle of less than 45 ° with respect to the XY plane, so that an incident light flux LB1a incident from the reflection mirror M12 to the reflection surface RPa of the polygon mirror PM is reflected toward the reflection mirror M10 provided at a position on the + X direction side of the polygon mirror PM and at a position on the + Z direction side of the polarization beam splitter PBS. The polygon mirror PM deflects the reflected light (hereinafter, the 1 st reflected light beam LB1b) of the incident light beam LB1a reflected by the reflection surface RPa in a plane including the optical axis AX4 and inclined with respect to the XY plane. The generatrix of the cylindrical lens CY2 extending in the Y direction is located on the plane in which the 1 st reflected light beam LB1b is polarized. A plane containing the optical axis AX1, AX3, AX4, and the rotation axis AXp is parallel to the XZ plane.

The cylindrical lens CY1 having a generatrix in the Y direction converges the incident light flux LB1a incident on the reflection surface RPa of the polygon mirror PM in a non-scanning direction (Z direction or direction of the rotation axis AXp) orthogonal to the main scanning direction (rotation direction, deflection direction) by the polygon mirror PM. That is, the cylindrical lens CY1 converges the incident beam LB1a on the reflection surface RPa into a slit shape (oblong shape) extending in the Y direction.

The 1 st reflected light beam LB1b reflected by the reflection surface RPa of the polygon mirror PM is incident on the reflection mirror M10 through the cylindrical lens CY 2. The 1 st reflected light beam LB1b reflected on the reflection surface RPa diverges in the non-scanning direction (Z direction) orthogonal to the main scanning direction by the polygon mirror PM and enters the cylindrical lens CY2, but becomes parallel light by the cylindrical lens CY2 having a generatrix in the Y direction. Therefore, the 1 st reflected light beam LB1b to be incident to the mirror M10 becomes a parallel light beam of substantially the same diameter as the incident light beam LB1a to be incident to the cylindrical lens CY 1. Further, the rear focal point of the cylindrical lens CY1 and the front focal point of the cylindrical lens CY2 coincide with each other within a predetermined allowable range on the reflection surface RPa.

The reflecting mirror M10 reflects the 1 st reflected light beam LB1b, which was originally reflected by the reflecting surface RPa of the polygon mirror PM, again toward the reflecting surface RPa of the polygon mirror PM. The reflected light of the 1 st reflected light beam LB1b (hereinafter, sometimes referred to as the 2 nd reflected light beam LB1c) reflected by the mirror M10 is incident on the reflection surface RPa through the cylindrical lens CY 2. Therefore, the 2 nd reflected light beam LB1c incident on the reflection surface RPa through the cylindrical lens CY2 converges on the reflection surface RPa in the non-scanning direction (Z direction or direction of the rotation axis AXp) orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM. That is, the cylindrical lens CY2 converges the 2 nd reflected light beam LB1c on the reflection surface RPa into a slit shape (oblong shape) extending in the Y direction. In a non-scanning direction (Z direction or direction of the rotation axis AXp) orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM, the converging position on the reflection surface RPa by the cylindrical lens CY1 and the converging position on the reflection surface RPa by the cylindrical lens CY2 are set to substantially the same position. Thereby, the thickness (length in the direction of the rotation axis AXp) of the polygon mirror PM can be made thin.

The reflection surface RPa of the polygon mirror PM reflects the 2 nd reflected light beam LB1c reflected by the mirror M10 toward the + X direction side. The reflected light of the light beam LB1 (the 2 nd reflected light beam LB1c) reflected again by the reflection surface RPa is sometimes referred to as a 3 rd reflected light beam LB1 d. The polygon mirror PM deflects the 3 rd reflected light beam LB1d in a plane parallel to the XY plane including the optical axis AX3 parallel to the X axis, and deflects in the Y direction around the optical axis AX 3. The 3 rd reflected light beam LB1d reflected again by the reflection surface RPa of the polygon mirror PM is incident on the polarization beam splitter PBS. Since the λ/4 wave plate QP is provided between the polygon mirror PM and the polarization beam splitter PBS, the 3 rd reflected light beam LB1d reflected again by the reflection surface RP of the polygon mirror PM and incident on the polarization beam splitter PBS is reflected toward the substrate P toward the-Z direction side by the polarization splitting surface Qs of the polarization beam splitter PBS. The polarization separation plane Qs reflects the light beam LB1d toward the f θ lens FT on the XZ plane so that the optical axis of the light beam LB1d overlaps the azimuth line Lx2 and the optical axis AXf of the f θ lens FT and advances.

The f θ lens FT is a scanning lens of a telecentric system that projects the principal ray of the light beam LB1d reflected by the polygon mirror PM onto the substrate P in parallel with the optical axis AXf in a plane orthogonal to the XZ plane including the optical axis AXf. The f θ lens FT scans the light beam LB1d projected onto the substrate P with the optical axis AXf as the center in the Y direction. The incident angle θ of the light beam LB1d to the f θ lens FT varies according to the rotation angle (θ/4) of the polygon mirror PM. The f θ lens FT projects the light beam LB1d to an image height position on the irradiated surface of the substrate P in proportion to the incident angle θ via the cylindrical lens CY 3. Further, the beam LB1d projected onto the substrate P is converged to the spot SP on the substrate P by the f θ lens FT and the cylindrical lens CY 3. A plane including the optical axes AX1, AX3, AX4, and AXf is parallel to the XZ plane, and when the incident angle θ to the f θ lens FT is 0 degree, the light beam LB1d incident on the f θ lens FT advances along the optical axis AXf. The f θ lens FT has a front focal point on the reflection surface RPa of the polygon mirror PM on which the light beam LB is incident, and a rear focal point on the substrate P. The rear focal point of the cylindrical lens CY3 is located on the substrate P. In modification 1, the same operation and effect as those of embodiment 1 can be obtained. Further, in the present modification, the incident angle of light flux LB1a or light flux LB1c incident on reflection surface RPa of polygon mirror PM is set smaller than that in fig. 6 and 7 (the incident angle is 45 °). Therefore, as compared with the case of fig. 6 and 7, the influence (degree of distortion of the drawing line SLn) due to a slight positional change in the Z direction of the reflected light beams LB1b and LB1d, which may be caused by the displacement of the reflection surface RP of the polygon mirror PM from the rotation axis AXp, can be reduced.

(modification 2) fig. 12 is a configuration diagram of modification 2 for reflecting the light LBn twice on the reflection surface RPa of the polygon mirror PM. The same components as those in embodiment 1 are denoted by the same reference numerals. The light beam LB1a incident on the polygon mirror PM is converged on the reflection surface RPa in a non-scanning direction (Z direction) orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM by a cylindrical lens having a generatrix in the Y direction, not shown. The light beam LB1b reflected by the reflection surface RPa of the polygon mirror PM enters the mirror M20 via the relay lens system G20. The mirror M20 reflects the incident light beam LB1b toward the reflection surface RPa of the polygon mirror PM. The reflected beam LB1c of the beam LB1b reflected by the mirror M20 passes through the relay lens system G20 again and enters the reflection surface RPa of the polygon mirror PM. The reflection surface RPa and the mirror M20 are in a conjugate relationship by the relay lens system G20. Therefore, the light beam LB1b to be incident on the mirror M20 converges in the Z direction on the reflection surface of the mirror M20 in the non-scanning direction (Z direction) orthogonal to the main scanning direction (deflecting direction) by the polygon mirror PM. The light beam LB1c incident on the reflection surface RPa of the polygon mirror PM from the mirror M20 also converges in the Z direction on the reflection surface RPa in the non-scanning direction (Z direction) orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM. Then, light beam LB1c incident on reflection surface RPa of polygon mirror PM again is reflected as light beam LB1d toward f θ lens FT. Further, in the Z direction orthogonal to the scanning direction of the polygon mirror PM, the convergence position of the light flux LB1a that has first entered the reflection surface RPa substantially coincides with the convergence position of the light flux LB1c that has again entered the reflection surface RPa. In modification 2, the same effects as those of embodiment 1 can be obtained. Further, by using a short focal length as the relay lens system G20, the optical path length from the polygon mirror PM to the mirror M20 can be shortened, or the aperture of the lens can be reduced.

[ embodiment 2 ]

Next, the scanner unit U1b according to embodiment 2 will be described. Fig. 13A is a view of the configuration of the scanner unit U1B of embodiment 2 as viewed from the-Y direction, and fig. 13B is a view of the configuration of the scanner unit U1B of embodiment 2 as viewed from the + Z direction. Note that the same reference numerals are given to the same components as those in embodiment 1. Since the scan cells Unb (U1b to U6b) have the same configuration, only the scan cell U1b will be described as an example. Further, in embodiment 2, the substrate P is transported in the + X direction in parallel with the XY plane. The scanning unit U1b includes cylindrical lenses CYa to CYd having generatrices in the Y direction, a polarization beam splitter PBS1, a PBS2, a λ/4 wave plate QP1, a QP2, an f θ lens FT1, an imaging lens FT2, a polygon mirror PM, and a mirror M30. The polarization beam splitter PBS1, PBS2, and λ/4 wave plates QP1 and QP2 constitute a beam splitting means, and the f θ lens FT1 and the cylindrical lens (3 rd optical member) CYd constitute a scanning optical system. The cylindrical lenses (1 st optical member) CYb, CYc and the mirror M30 constitute a re-reflection optical system.

A light beam LB1 of a parallel light beam reflected toward the-Z direction by an incident mirror (light guide member) IM1 shown in fig. 5 is incident to the scanning unit U1b along an optical axis AX1 parallel to the Z axis. In the present embodiment, the light beam LB1 (hereinafter, also referred to as an incident light beam LB1a) to be incident on the scanning unit U1b is condensed on the surface p1 by a condenser lens (not shown) into a circular spot, and then is incident on the scanning unit U1b, so that the light beam is incident on the scanning unit U1b while diverging. The incident light beam LB1a incident on the scanning unit U1b is incident on the polarization beam splitter PBS1 through a cylindrical lens (2 nd optical member) CYa having a generatrix in the Y direction provided along the optical axis AX 1. The polarization splitting plane Qs of the polarization beam splitter PBS1 is inclined at 45 degrees to the XY plane, and reflects the light of P-polarized light and transmits the light of S-polarized light. Therefore, the incident light beam LB1a (light of P-polarized light) incident on the polarization beam splitter PBS1 through the cylindrical lens CYa is reflected toward the-X direction side by the polarization splitting plane Qs of the polarization beam splitter PBS 1. The incident light beam LB1a reflected in the-X direction by the polarization splitting plane Qs of the polarization beam splitter PBS1 is incident on the reflection plane RPa of the polygon mirror PM via the λ/4 wave plate QP1 and the f θ lens FT1 provided in the-X direction of the polarization beam splitter PBS 1. The optical axis AXf1 of the f θ lens FT1 is set parallel to the X axis, and the rotation axis AXp of the polygon mirror PM is set parallel to the Z axis. The plane containing the optical axis AXf1 and the rotation axis AXp is parallel to the XZ plane. At this time, the incident light flux LB1a enters the f θ lens FT1 from the exit side of the f θ lens FT 1. The reflection surface RP of the polygon mirror PM is disposed at the position of the entrance pupil of the f θ lens FT1 (the position of the front focal point).

Here, the cylindrical lens CYa collimates the incident beam LB1a, which is incident while diverging in one plane, in a non-scanning direction (Z direction) orthogonal to the main scanning direction (rotation direction, deflection direction) by the polygon mirror PM (see fig. 13A). The cylindrical lens CYa transmits the incident beam LB1a that is incident while diverging in the main scanning direction (rotation direction and deflection direction) by the polygon mirror PM (see fig. 13B). Further, the front focal point of the cylindrical lens CYa is set on the plane p 1. The f θ lens FT1 converges the incident light flux LB1a, which is a parallel light flux formed by the cylindrical lens CYa, on the reflection surface RPa of the polygon mirror PM in the non-scanning direction orthogonal to the main scanning direction (the rotational direction and the deflection direction) by the polygon mirror PM (see fig. 13A). The f θ lens FT1 collimates the light beam LB1a, which is incident while diverging, in an XY plane that is the main scanning direction (rotation direction and deflection direction) by the polygon mirror PM (see fig. 13B). Thereby, the incident beam LB1a projected on the reflection surface RPa converges on the reflection surface RP into a slit shape (oblong shape) extending in the Y direction (see fig. 13A and 13B).

Further, in the XZ plane, the incident light flux LB1a that advances from the polarization beam splitter PBS1 toward the reflection surface RPa of the polygon mirror PM through the f θ lens FT1 enters the reflection surface RPa through a position on the + Z direction side of the optical axis AXf1 of the f θ lens FT1, and a position converging on the reflection surface RPa substantially coincides with the optical axis AXf1 of the f θ lens FT1 (see fig. 13A). Further, in the XY plane, the incident light beam LB1a heading from the polarization beam splitter PBS1 toward the reflection surface RPa of the polygon mirror PM through the f θ lens FT1 overlaps the optical axis AXf1 of the f θ lens FT1 and enters the reflection surface RPa (see fig. 13B). Here, the reflection surface RPa of the polygon mirror PM is set at the pupil position (the position of the front focal point) of the f θ lens FT1, and the rear focal point of the f θ lens FT1 is set at the position of the surface p2 distant from the polarization beam splitter PBS1 in the + X direction in fig. 13A and 13B. The plane P2 is set in an optically conjugate relationship with the plane P1 and is set in a relationship of ultimately being conjugate with the surface of the substrate P.

The reflection surface RPa of the polygon mirror PM reflects the incident light flux LB1a toward the + X direction side toward the f θ lens FT 1. The incident light flux LB1a is deflected in the Y direction by the rotation of the polygon mirror PM. The reflected light of the incident light beam LB1a reflected by the reflection surface RPa (hereinafter referred to as a 1 st reflected light beam LB1b) is deflected in the Y direction on the XY plane around the optical axis AXf1 by the rotating polygon mirror PM. The 1 st reflected light beam LB1b reflected on the reflection surface RPa passes through the optical axis AXf1 of the f θ lens FT1 on the-Z direction side on the XZ plane and enters the f θ lens FT 1.

The 1 st reflected light beam LB1b directed from the reflection surface RPa toward the f θ lens FT diverges in a non-scanning direction orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM and enters the f θ lens FT1, but becomes parallel light by the f θ lens FT1 (see fig. 13A). The 1 st reflected light beam LB1B directed from the reflection surface RPa toward the f θ lens FT enters the f θ lens FT1 as parallel light in an XY plane including the main scanning direction (deflection direction) by the polygon mirror PM, but converges to a circular point on the plane p2 by the f θ lens FT1 (see fig. 13B).

The 1 st reflected light beam LB1b transmitted through the f θ lens FT1 is transmitted through the λ/4 wave plate QP2 and enters the polarizing beam splitter PBS 2. The λ/4 wave plate QP2 and the polarization beam splitter PBS2 are disposed on the-Z direction side of the λ/4 wave plate QP1 and the polarization beam splitter PBS1 via the light shielding plate DO. The light shielding plate DO is disposed on a plane parallel to the XY plane and including the optical axis AXf1 of the f θ lens FT 1. The polarization splitting plane Qs of the polarization beam splitter PBS1 is inclined at 45 degrees to the XY plane, and reflects the light of P-polarized light and transmits the light of S-polarized light. Here, the incident light beam LB1a initially incident on the polygon mirror PM is converted from P-polarized light to circularly polarized light by the λ/4 wave plate QP1, and the 1 st reflected light beam LB1b initially reflected on the polygon mirror PM is converted from circularly polarized light to S-polarized light by the λ/4 wave plate QP 2. Therefore, the 1 st reflected beam LB1b incident on the PBS2 is transmitted directly through the PBS 2.

The 1 st reflected light beam LB1b transmitted through the polarization beam splitter PBS2 and heading toward the + X direction side passes through a cylindrical lens (1 st optical member) CYb and an imaging lens FT2 disposed on the + X direction side of the polarization beam splitter PBS2, and enters the mirror M30. The cylindrical lens CYb having the rear focal point set on the surface p2 converges the 1 st reflected light beam LB1b of the parallel light transmitted through the f θ lens FT1 and the polarization beam splitter PBS2 on the surface p2 in the non-scanning direction (Z direction) orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM (see fig. 13A). Since the surface p2 is also the position of the rear focal point of the f θ lens FT1, the 1 st reflected light beam LB1B transmitted through the f θ lens FT1 and the polarization beam splitter PBS2 converges on the surface p2 in the main scanning direction (deflecting direction) by the polygon mirror PM (see fig. 13B). The plane p1 is in conjugate relation with the plane p 2. The mirror M30 is disposed as a concave spherical mirror at the pupil position, which is the position of the rear focal point of the imaging lens FT2, for aberration correction, but may be a plane mirror in principle. Further, a system in which the imaging lens FT2 and the mirror M30 are combined functions as an equal-magnification relay optical system having telecentric imaging characteristics on the surface p2 side, and a spot condensed on the surface p2 by the convergence of the light beam LB1b is imaged at a different position on the surface p2 as a spot converged on the light beam LB1 c.

Therefore, the 1 st reflected light beam LB1b directed toward the mirror M30 through the imaging lens FT2 enters the imaging lens FT2 in a divergent state, but enters the mirror M30 after passing through the imaging lens FT2 as a parallel light beam. Further, an optical axis AXf2 of the imaging lens FT2 and an optical axis AXf1 of the f θ lens FT1 are coaxially set. The 1 st reflected light beam LB1b to be incident on the imaging lens FT2 is incident on the imaging lens FT2 through the-Z direction side of the optical axis AXf2 on the XZ plane, and the center axis of the 1 st reflected light beam LB1b coincides with the optical axis AXf2 on the mirror M30 (refer to fig. 13A). The position of the rear focal point (pupil plane) of the imaging lens FT2 is set on the plane p 2.

The reflected light of the 1 st reflected light beam LB1b (hereinafter, referred to as a 2 nd reflected light beam LB1c) reflected toward the-X direction side by the mirror M30 passes through the imaging lens FT2 and the cylindrical lens (1 st optical member) CYc and is again incident on the polarization beam splitter PBS 1. The 2 nd reflected light beam LB1c is incident on the imaging lens FT2 through the + Z direction side of the optical axis AXf 2. The imaging lens FT2 converges the 2 nd reflected light beam LB1c of the parallel light beam reflected by the mirror M30 to a circular point on the plane p 2. The 2 nd reflected beam LB1c converged at the surface p2 diverges in one plane, and enters the polarizing beam splitter PBS1 after entering the cylindrical lens CYc having a generatrix parallel to the Y axis in one plane. The 2 nd reflected light beam LB1c incident on the polarizing beam splitter PBS1 becomes parallel light in the non-scanning direction (Z direction) orthogonal to the main scanning direction (deflecting direction) by the polygon mirror PM, and is directly diffused in the main scanning direction (deflecting direction) by the polygon mirror PM and incident on the polarizing beam splitter PBS 1. Since the 2 nd reflected light beam LB1c to be incident on the polarizing beam splitter PBS1 becomes S-polarized light, it is directly transmitted through the polarizing beam splitter PBS 1. The 2 nd reflected light beam LB1c transmitted by the polarization beam splitter PBS1 is again incident on the reflection surface RPa of the polygon mirror PM through the λ/4 wave plate QP1 and the f θ lens FT 1. The 2 nd reflected light beam LB1c enters the f θ lens FT1 from the exit side of the f θ lens FT 1.

The f θ lens FT1 converges the incident 2 nd reflected light beam LB1c on the reflection surface rp (rpa) of the polygon mirror PM into a slit shape (oblong shape) extending in the Y direction. At this time, in the Z direction orthogonal to the scanning direction (deflecting direction) of the polygon mirror PM, the incident position on the reflection surface RPa of the 2 nd reflected light beam LB1c coincides with the incident position on the reflection surface RPa of the incident light beam LB1 a. The reflected light of the 2 nd reflected light beam LB1c reflected again by the reflection surface RPa (hereinafter, referred to as the 3 rd reflected light beam LB1d) is incident on the polarization beam splitter PBS2 through the f θ lens FT1 and the λ/4 wave plate QP 2. Here, the 2 nd reflected light beam LB1c re-incident on the polygon mirror PM is converted from S-polarized light to circularly polarized light by the λ/4 wave plate QP1, and the 3 rd reflected light beam LB1d re-reflected on the polygon mirror PM is converted from circularly polarized light to P-polarized light by the λ/4 wave plate QP 2. Therefore, the 3 rd reflected light beam LB1d to be incident on the polarizing beam splitter PBS2 is reflected in the-Z direction by the polarization splitting plane Qs of the polarizing beam splitter PBS2 and projected onto the substrate P. The 3 rd reflected light beam LB1d reflected toward the-Z direction by the polarization separation plane Qs is projected to the substrate P through the cylindrical lens (3 rd optical member) CYd. The light beam LB1 (the 3 rd reflected light beam LB1d) projected toward the substrate P from the scanning unit U1b is projected along the normal line of the substrate P.

Here, the f θ lens FT1 converges the 3 rd reflected light beam LB1d of the parallel light beam incident upon being reflected by the reflection surface RPa on the substrate P in the scanning direction (deflecting direction) of the polygon mirror PM. The f θ lens FT1 collimates the 3 rd reflected light beam LB1d that is reflected by the reflection surface RPa, diverges while diverging, and enters while being reflected, in a direction orthogonal to the scanning direction (deflecting direction) of the polygon mirror PM, and converges on the substrate P by the cylindrical lens CYd. Thus, the light beam LB1 (the 3 rd reflected light beam LB1d) projected onto the substrate P becomes the spot SP and is projected onto the substrate P. Thus, the surface P1, the surface P2, and the substrate P are in a conjugate relationship with each other.

Here, as shown in fig. 13A, in a direction (on the XZ plane) orthogonal to the scanning direction (deflection direction) of the polygon mirror PM, the optical path of the 1 st reflected light beam LB1b directed from the reflection surface RPa of the polygon mirror PM toward the mirror M10, the shape, and the optical path and the shape of the 2 nd reflected light beam LB1c directed from the mirror M30 toward the reflection surface RPa of the polygon mirror PM are symmetrical with respect to a plane including the optical axis AXf1(AXf2) and parallel to the XY plane. The optical path and shape of the incident beam LB1a that first goes to the reflection surface RPa of the polygon mirror PM from the polarizing beam splitter PBS1 are the same as the optical path and shape of the 2 nd reflected beam LB1c that goes again to the reflection surface RPa of the polygon mirror PM from the polarizing beam splitter PBS1 in the direction (on the XZ plane) orthogonal to the scanning direction (deflecting direction) of the polygon mirror PM. Further, the optical path and shape of the 1 st reflected light beam LB1b directed from the reflection surface RPa of the polygon mirror PM toward the polarizing beam splitter PBS2 are the same as the optical path and shape of the 3 rd reflected light beam LB1d directed from the reflection surface RPa of the polygon mirror PM toward the polarizing beam splitter PBS2 in the direction (on the XZ plane) orthogonal to the scanning direction (deflecting direction) of the polygon mirror PM.

On the other hand, as shown in fig. 13B, the optical paths of the 1 st reflected light beam LB1B to the 3 rd reflected light beam LB1d are different depending on the angle of the reflection surface RPa of the polygon mirror PM in the scanning direction (the deflecting direction) of the polygon mirror PM (on the XY plane). Here, an angle of the reflection surface RPa with respect to the YZ plane is Δ θ. In the scanning direction (deflecting direction) of the polygon mirror PM (on the XY plane), the angle (absolute value) of the central axis (principal ray) of the 1 st reflected light beam LB1b reflected by the reflection surface RPa of the polygon mirror PM and incident on the f θ lens FT1 with respect to the optical axis AXf1 of the f θ lens FT1 (central axis of the incident light beam LB1a) becomes 2 × Δ θ. Further, in the scanning direction (deflecting direction) of the polygon mirror PM (on the XY plane), the angle (absolute value) of the central axis (principal ray) of the 2 nd reflected light beam LB1c, which is again incident on the reflection surface RP of the polygon mirror PM, with respect to the optical axis AXf1 of the f θ lens FT1 (central axis of the incident light beam LB1a) becomes 2 × Δ θ. Therefore, in the scanning direction (deflecting direction) of the polygon mirror PM (on the XY plane), the central axis (principal ray) or convergent-divergent state of the 1 st reflected light beam LB1b reflected by the reflection surface RPa of the polygon mirror PM and incident on the f θ lens FT1, and the central axis (principal ray) or convergent-divergent state of the 2 nd reflected light beam LB1c re-incident on the reflection surface RP of the polygon mirror PM are symmetrical with respect to the optical axis AXf1 (central axis of the incident light beam LB1 a). In the scanning direction (deflecting direction) of the polygon mirror PM (on the XY plane), the angle (absolute value) of the optical axis (central axis) of the 3 rd reflected light beam LB1d reflected by the reflection surface RPa of the polygon mirror PM and incident on the f θ lens FT1 with respect to the optical axis AXf1 of the f θ lens FT1 (central axis of the incident light beam LB1a) is 4 × Δ θ.

Therefore, the effect equivalent to that of embodiment 1 can be obtained also in embodiment 2. The system in which the imaging lens FT2 and the mirror M30 are combined as shown in fig. 13A and 13B is a telecentric equal-magnification relay optical system similar to the relay lens system G20 shown in fig. 12, and the configuration from the surface p2 to the mirror M30 can be miniaturized by using a short focal length as the imaging lens FT 2.

[ modification of embodiment 2 ]

The embodiment 2 can be modified as described below.

In modification 1, in the case of the scanner unit Unb according to embodiment 2, the scanner unit Unb is longer in the direction of the optical axes AXf1 and AXf2 of the f θ lens FT1 and the imaging lens FT 2. Therefore, as shown in fig. 14, when the substrate P is supported by being bent by the drum DR described in embodiment 1 and a plurality of scanning units Unb described in embodiment 2 are arranged along the conveyance direction of the substrate P, it is necessary to arrange the scanning units Unb arranged along the conveyance direction (X direction) of the substrate P at intervals in the X direction (circumferential direction of the drum DR) according to the odd number and the even number of the scanning units Unb. Accordingly, the distance between the drawing lines SLn (projection positions of the light spot SP) of the plurality of scanning units Unb arranged along the conveyance direction becomes longer. Therefore, if only 1 alignment microscope AMm (AM1 to AM4) on the upstream side of the plurality of scanning units Unb is provided in the conveyance direction of the substrate P, the alignment accuracy may be lowered. Therefore, in modification 1, as shown in fig. 14, a plurality of alignment microscopes AMm (AM1 to AM4) may be provided on the upstream side in the conveyance direction of the substrate P with respect to the positions of the odd-numbered scanning cells Unb and the even-numbered scanning cells Unb provided along the conveyance direction of the substrate P.

(modification 2) in the above-described embodiment 2, 1 light beam LB1a is incident on 1 scanning unit Unb, but 2 light beams LBn (LB1a) may be slightly separated in the Y direction and incident on the cylindrical lens CYa of 1 scanning unit Unb. In this case, each central axis of the 2 light fluxes LB1a to be incident to the cylindrical lens CYa is parallel to the optical axis AX1 and is located on a plane parallel to a YZ plane containing the optical axis AX 1. Thus, since scanning is performed by 2 spots SP, a pattern can be drawn at a higher speed. Further, by making 2 light beams LB1a incident on the scanning unit Unb so as to be divided into scanning areas of 2 spots SP, the rotation angle contributing to the actual scanning of the polygon mirror PM can be further halved.

[ embodiment 3 ]

In the above-described embodiments 1 and 2 (including the modifications), the light beam LBn is made incident on the polygon mirror PM in the same manner as the reflection surface RP of the polygon mirror PM that reflects the light beam LBn (LB1a) for the 1 st time and the reflection surface RP of the polygon mirror PM that reflects the light beam LBn (LB1c) for the 2 nd time. However, in embodiment 3, the configuration of the re-reflecting optical member is changed so that the reflection surface RP of the polygon mirror PM that reflects the light flux LBn for the 1 st time is different from the reflection surface RP of the polygon mirror PM that reflects the light flux LBn for the 2 nd time.

Fig. 15 is a diagram illustrating a configuration for reflecting the drawing light flux LBn twice by the polygon mirror PM in embodiment 3. The same reference numerals are given to the same components as those in the above-described embodiments 1 and 2. In the present embodiment, the re-reflecting optical member is configured such that the reflection surface RP of the polygon mirror PM that reflects the light flux LBn for the 1 st time is different from the reflection surface RP of the polygon mirror PM that reflects the light flux LBn for the 2 nd time.

In fig. 15, a light beam LB1a incident on the polygon mirror PM is converged on the reflection surface RPa in a non-scanning direction (direction of the rotation axis AXp) orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM by a cylindrical lens having a generatrix in the Y direction, not shown. The light beam LB1b reflected by the reflection surface RPa of the polygon mirror PM enters the mirror M50 through the relay lens system G30 and is reflected by the mirror M50, and then enters the mirror M51. The reflection surface RPa and the mirror M51 are in a conjugate relationship by the relay lens system G30. Therefore, the light beam LB1b to be incident on the mirror M51 converges on the reflection surface of the mirror M51 in the non-scanning direction (the direction of the rotation axis AXp) orthogonal to the main scanning direction (the deflecting direction) by the polygon mirror PM. The light beam LB1c reflected by the mirror M51 is reflected by the mirror M52, passes through the relay lens system G31, and enters the reflection surface RP of the polygon mirror PM. The reflection surface RP on which the light beam LB1c enters through the relay lens system G31 is a reflection surface RP (hereinafter, RPb) different from the reflection surface RPa. The mirror M51 and the reflecting surface RPb have a conjugate relationship by the relay lens system G31. Therefore, the light beam LB1c incident on the reflection surface RPb converges on the reflection surface RPb in the non-scanning direction (the direction of the rotation axis AXp) orthogonal to the main scanning direction (the deflection direction) by the polygon mirror PM. Then, the light beam LB1d reflected on the reflection surface RPb of the polygon mirror PM is reflected toward the f θ lens FT. Further, in the direction orthogonal to the scanning direction of the polygon mirror PM, the position where the light flux LBn converges on the reflection surface RPa (the position in the direction in which the rotation axis AXp extends) and the position where the light flux LBn converges on the reflection surface RPb (the position in the direction in which the rotation axis AXp extends) coincide.

In the present embodiment described above, the relay lens systems G30 and G31 and the mirrors M50, M51, and M52 in fig. 15 constitute a re-reflection optical system, and exhibit the same operation and effect as those of the above-described embodiment 1.

(modification 1) fig. 16 is a diagram showing a configuration for reflecting the beam LBn twice by the polygon mirror PM in modification 1 of embodiment 3 (fig. 15). The same components as those in embodiment 3 are denoted by the same reference numerals. In modification 1, the configuration of the re-reflecting optical system that causes the light flux LBn to enter the polygonal mirror PM is different from the configuration of fig. 15 in that the reflection surface RP of the polygonal mirror PM that reflects the light flux LBn for the 1 st time is different from the reflection surface RP of the polygonal mirror PM that reflects the light flux LBn for the 2 nd time.

The light beam LB1a to be incident on the polygon mirror PM is converged on the reflection surface RPa in a non-scanning direction (direction of the rotation axis AXp) orthogonal to the main scanning direction (deflection direction) by the polygon mirror PM by a cylindrical lens having a generatrix in the Y direction, not shown. The light beam LB1b reflected by the reflection surface RPa of the polygon mirror PM passes through the lens system G50a and then enters the mirror M60. The light beam LB1b reflected by the mirror M60 is incident on the mirror M61. The light beam LB1c reflected by the mirror M61 is incident on the reflection surface RPb of the polygon mirror PM through the lens system G50 b. The reflection surface RPb is a reflection surface RP different from the reflection surface RPa. The lens systems G50a and G50b constitute a relay lens system G50 in which a pupil plane ep is formed at an intermediate position (between the mirrors M60 and M61) in the optical path, and the reflection surfaces RPa and RPb are in a conjugate relationship with each other by the relay lens system G50. Therefore, the light beam LB1c to be incident on the reflection surface RPb converges on the reflection surface RPb in the non-scanning direction (the direction of the rotation axis AXp) orthogonal to the main scanning direction (the deflection direction) by the polygon mirror PM. Then, the light flux LBn reflected on the reflection surface RPb of the polygon mirror PM is reflected toward the f θ lens FT. Further, in the direction orthogonal to the scanning direction of the polygon mirror PM, the position where the light flux LB1a converges on the reflection surface RPa (the position in the direction in which the rotation axis AXp extends) and the position where the light flux LBn converges on the reflection surface RPb (the position in the direction in which the rotation axis AXp extends) coincide. In modification 1, the same effects as those of embodiment 1 can be obtained.

[ modifications of the 1 st to 3 rd embodiments ]

In the above embodiments, the polygon mirror PM is used as the movable reflecting member, but the beam LBn may be deflected by using a swinging reflecting member such as a galvanometer mirror. When the galvanometer mirror GM is used, the scanning unit U1d shown in fig. 17 may be used. The same reference numerals are given to the same configurations as those of the above-described embodiments 1 to 3. Since the scanning units Und (U1 d-U6 d) have the same configuration, only the scanning unit U1d will be described as an example.

The optical axis AXf of the f θ lens FT is arranged parallel to the X axis of the orthogonal coordinate system XYZ, and the rotation (vibration) center axis Cg of the galvanometer mirror (movable reflecting member, swinging reflecting member) GM is arranged parallel to the Z axis. The 1 st reflecting surface m10 and the 2 nd reflecting surface m11 of the galvanometer mirror GM are set so that a neutral position (a deflection angle of 0 degrees) parallel to the Z axis and parallel to the vibration around the rotation center axis Cg is at an angle of 45 degrees in the XY plane with respect to the optical axis AXf of the f θ lens FT. The galvanometer mirror GM vibrates (oscillates) within a predetermined range of a deflection angle ± θ g. When the 1 st reflecting surface m10 is, for example, the front surface of the galvanometer mirror GM, the 2 nd reflecting surface m11 is the rear surface of the galvanometer mirror GM.

The light beam LB1 (hereinafter, incident light beam LB1a) incident to the scanning unit U1d is bent in its optical path by a mirror or the like, then advances in the-Y direction, and is incident on the 1 st reflection surface m10 of the galvanometer mirror GM. The reflected light of the incident light beam LB1a (hereinafter, the 1 st reflected light beam LB1b) reflected by the 1 st reflecting surface m10 of the galvanometer mirror GM is reflected by the mirrors MRa, MRb and is again incident to the galvanometer mirror GM. At this time, the reflected light of the 1 st reflected light beam LB1b reflected by the mirrors MRa, MRb (hereinafter, the 2 nd reflected light beam LB1c) enters the 2 nd reflecting surface m11 of the galvanometer mirror GM. The reflected light of the 2 nd reflected light beam LB1c (hereinafter, the 3 rd reflected light beam LB1d) reflected by the 2 nd reflecting surface m11 is projected as a spot SP onto the substrate P through the f θ lens FT.

Further, in the beam scanning unit using the galvanometer mirror GM, a cylindrical lens for correcting the surface inclination of the reflection surface is not provided, but when the surface inclination correction is necessary, an optical system including a cylindrical lens for converging each of the incident beam LB1a and the 2 nd reflected beam LB1c on the 1 st reflection surface m10 and the 2 nd reflection surface m11 in a direction orthogonal to the scanning direction may be provided on the optical path of the beam LB. In this case, a cylindrical lens that converges the 3 rd reflected light beam LB1d on the substrate P in a direction orthogonal to the scanning direction of the galvanometer mirror GM is provided between the f θ lens FT and the substrate P. With the configuration shown in fig. 17, even when the galvanometer mirror GM is used, the 1 st reflecting surface m10 for deflecting the incident light beam LB1a may be different from the 2 nd reflecting surface m11 for deflecting the 2 nd reflected light beam LB1 c. Since the deflection angle of the galvanometer mirror GM is ± θ g, the 3 rd reflected light beam LB1d deflected in a range of ± 4 θ g around the optical axis AXf enters the f θ lens FT. Therefore, the present modification also exhibits the same effects as those of the above-described embodiment 1. The galvanometer mirror GM is poor in linearity at both ends of the range of the deflection angle, and therefore, usually, the beam scanning is performed in a narrow deflection angle range in which linearity is good including the center position of the amplitude angle of the oscillation, but by providing a re-reflection optical member by the mirrors MRa, MRb as shown in fig. 17, the beam scanning in good linearity can be performed in a wide angle range.

Claims (9)

1. An optical beam scanning device for projecting a light beam deflected by a movable reflecting member whose reflecting surface angle is changed, onto an irradiation object, the optical beam scanning device comprising:

a re-reflection optical system including a mirror that reflects a 1 st reflected light beam reflected first by the movable reflection member and generates a 2 nd reflected light beam directed toward the movable reflection member, and a 1 st optical member that converges the 2 nd reflected light beam in a non-deflecting direction intersecting a deflecting direction of the light beam generated by the movable reflection member;

a scanning optical system that receives the 2 nd reflected light beam, reflects the 3 rd reflected light beam again by the movable reflecting member, and emits the 3 rd reflected light beam toward the irradiation object; and

a light splitting member provided between the movable reflecting member and the re-reflecting optical system; and is

The 1 st reflected light beam initially reflected by the movable reflecting member is incident on the re-reflecting optical system via the light splitting member, and the 2 nd reflected light beam directed from the re-reflecting optical system toward the movable reflecting member is incident on the scanning optical system via the light splitting member.

2. The optical beam scanning apparatus according to claim 1, wherein said optical beam that is initially incident to said movable reflecting member and said 2 nd reflected optical beam that is re-incident are set at the same position in said non-deflecting direction on a reflecting surface of said movable reflecting member.

3. The optical beam scanning device according to claim 1 or 2, further comprising a 2 nd optical member that converges the optical beam that is initially incident on the movable reflecting member in the non-deflecting direction, and wherein

The scanning optical system includes an f θ lens system that is incident on the 3 rd reflected light beam reflected again by the movable reflecting member, and a 3 rd optical member that converges the 3 rd reflected light beam directed from the f θ lens system toward the irradiation object in the non-deflecting direction.

4. An optical beam scanning apparatus according to claim 1 or 2, wherein the beam splitting means comprises a polarizing beam splitter and a wave plate, and

the light beam that is initially incident on the movable reflecting member is linearly polarized light.

5. An optical beam scanning device for projecting a light beam deflected by a movable reflecting member whose reflecting surface angle is changed, onto an irradiation object, the optical beam scanning device comprising:

a re-reflection optical system including a mirror that reflects a 1 st reflected light beam reflected first by the movable reflection member and generates a 2 nd reflected light beam directed toward the movable reflection member, and a 1 st optical member that converges the 2 nd reflected light beam in a non-deflecting direction intersecting a deflecting direction of the light beam generated by the movable reflection member;

a scanning optical system that receives the 2 nd reflected light beam, reflects the 3 rd reflected light beam again by the movable reflecting member, and emits the 3 rd reflected light beam toward the irradiation object; and

a light guide member that guides the light beam that first enters the movable reflection member so as to enter from an exit side of the scanning optical system; and is

The movable reflecting member reflects the light beam incident from the emission side of the scanning optical system toward the scanning optical system as the 1 st reflected light beam,

the re-reflection optical system makes the 1 st reflected light beam reflected by the movable reflection member and passing through the scanning optical system incident from an exit side of the scanning optical system and reflected as the 2 nd reflected light beam toward the movable reflection member,

the scanning optical system further enters the 3 rd reflected light beam which is reflected again by the 2 nd reflected light beam passing through the movable reflecting member and is emitted toward the irradiation object,

the optical beam scanning device further includes:

a 1 st beam splitting member that is provided between the scanning optical system and the re-reflecting optical system, and that is configured to split the optical path of the light beam incident on the scanning optical system from the light guide member and split the optical path of the 2 nd reflected light beam reflected by the re-reflecting optical system and directed toward the movable reflecting member through the scanning optical system; and

a 2 nd spectroscopic member that is provided between the scanning optical system and the re-reflecting optical system, and that has an optical path of the 1 st reflected light beam that has been reflected by the movable reflecting member first and has passed through the scanning optical system, and an optical path of the 3 rd reflected light beam that has been reflected by the movable reflecting member again and has passed through the scanning optical system; and is

Projecting the 3 rd reflected light beam to the irradiated body via the 2 nd spectroscopic member.

6. A pattern drawing apparatus for drawing a pattern on a substrate by projecting a light beam onto the substrate as the irradiation object and scanning the light beam in a main scanning direction intersecting with a predetermined direction using the light beam scanning apparatus according to any one of claims 1 to 5 in a state where the substrate is moved in the predetermined direction.

7. The pattern drawing apparatus according to claim 6, wherein a plurality of the light beam scanning devices are arranged along at least one of a moving direction of the substrate and a main scanning direction.

8. The pattern drawing apparatus according to claim 7, comprising an alignment system for detecting a predetermined mark formed on the substrate, and wherein the pattern drawing apparatus comprises

The alignment systems are provided corresponding to positions of the plurality of light beam scanning devices arranged along the moving direction of the substrate.

9. The pattern rendering apparatus of claim 6, wherein the substrate is a flexible, elongated sheet substrate, and

the pattern drawing device further includes a drum having a central axis extending in a width direction intersecting with a longitudinal direction of the sheet substrate and a cylindrical outer peripheral surface having a constant radius from the central axis, and the drum is provided with a plurality of rollers

The drum moves the sheet substrate in the longitudinal direction while rotating about the central axis while supporting the sheet substrate so that a part of the sheet substrate is bent in the longitudinal direction while facing the outer peripheral surface

The light beam scanning device projects the light beam onto the sheet substrate supported by the drum.

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