KR20190003748A - Beam scanning device and drawing device - Google Patents

Abstract

The scanning unit Un which is a beam scanning device for scanning the beam LBn in one dimension on the substrate P includes a first cylindrical lens CY1 having power in one direction and a first cylindrical lens CY1 A fθ lens system FT for projecting the beam LBn deflected in a telecentric state onto the substrate P, and a fθ lens system FT for deflecting the beam LBn deflected in the telecentric state onto the substrate P, and a second cylindrical lens (CY2) incident on the beam (LBn) transmitted through the f? lens system (FT) and having power in one direction, wherein the first cylindrical lens (CY1) and the second cylindrical lens (CY2) has power in directions orthogonal to each other and further includes a lens system (G10) provided between the first cylindrical lens (CY1) and the polygon mirror (PM).

Description

Beam scanning device and drawing device

The present invention relates to a beam scanning device for scanning a beam in one dimension in a main scanning direction in order to draw a predetermined pattern on a substrate and a beam scanning device for scanning a predetermined pattern And to a drawing apparatus for drawing.

it is known that a beam projected onto a photosensitive material can be scanned at a constant velocity (constant velocity) by using an f? lens system and a polygon mirror (a rotary polygon mirror). Each reflection surface of a general polygon mirror is formed parallel to a direction orthogonal to the rotation plane (plane including the rotation direction) of the polygon mirror, but the actual reflection surface is slightly inclined with respect to the direction perpendicular to the rotation plane of the polygon mirror Error, so-called tangle (tilt) error. Since the error differs depending on the reflection surface, the phase position (the projection position of the beam) of the spot light that forms an image on the image sensing material by the f? Lens system deviates from each reflection surface.

In order to prevent the deviation of the projection position, Japanese Unexamined Patent Publication (Kokai) No. Hei 8-297255 discloses a method of correcting a deflection angle of a polygon mirror in a deflection direction (scanning direction, rotation direction of a polygon mirror The cylindrical lens having refractive power only in the orthogonal direction is arranged. That is, two cylindrical lenses whose bus lines are parallel to the scanning direction of the beam are arranged. As a result, with respect to the direction (sub scanning direction) orthogonal to the scanning direction of the beam (main scanning direction), the reflecting surface of the polygon mirror and the surface to be irradiated of the reflecting material are in a conjugate relationship So that even if the surface tangle error is irregularly distributed on each reflection surface of the polygon mirror, the projection position on the surface of the beam can be made constant in the sub scanning direction.

However, as disclosed in Japanese Patent Application Laid-Open No. 8-297255, there is a method in which a first cylindrical lens disposed immediately before the polygon mirror and a second cylindrical lens disposed behind the f? Lens system (composed of a plurality of spherical lenses) In the case where each of the first and second cylindrical lenses is made of a single lens and the bus bar of the first cylindrical lens and the bus bar of the second cylindrical lens are made parallel to each other, (Aberration correction) for satisfactorily reducing the spherical aberration (for example, the spherical aberration of the beam).

A first aspect of the present invention is a beam scanning apparatus for scanning a beam from a light source device onto a workpiece in a one-dimensional manner on the workpiece, the beam scanning device comprising: A first optical member that condenses (collects) light in a first direction, and a beam deflector that inclines the beam passing through the first optical member and deflects the beam in the first direction for the one- A main optical system for entering the beam deflected by the beam deflection member and for projecting the beam toward the object to be irradiated, and a second optical system for entering the beam passing through the main optical system, And a second optical member that is provided between the first optical member and the beam deflecting member and that has transmitted the beam that has passed through the first optical member at a position of the beam deflecting member, And a lens system for focusing the second direction.

A second aspect of the present invention is a method for forming a pattern on a workpiece by relatively moving a workpiece and a beam in a sub scanning direction while scanning a beam from a light source device on a workpiece in a main scanning direction, A movable deflecting member that deflects the beam in one dimension in the main scanning direction to scan the beam in the main scanning direction; and a deflecting member that deflects the deflecting member in one dimension A first optical member having an anisotropic refracting power and converging the beam toward the movable deflecting member with respect to the main scanning direction; a second optical member for converging the beam toward the movable deflecting member in the main scanning direction; And converging the beam, which is emitted from the main optical system and is directed to the object, with respect to the sub-scanning direction, Scanning direction; and a second optical member which is provided between the first optical member and the movable deflecting member and which converts the beam converged with respect to the main scanning direction into a beam converging with respect to the sub- And a third optical member having an isotropic refractive power that is emitted toward the movable deflecting member.

A third aspect of the present invention is a projection exposure apparatus for projecting a beam deflected in a first direction on a movable deflecting member onto a workpiece while projecting it onto a workpiece by a main optical system, A drawing apparatus for drawing a pattern, comprising: a first adjusting optical system including a first lens member having an anisotropic refractive power for converging the beam projected on the movable deflecting member with respect to a second direction orthogonal to the first direction; And a second lens element having an anisotropic refractive power for converging the beam from the injection optical system to the object in the second direction, wherein the wavelength of the beam is λ, wherein the numerical aperture NA on the second direction _x, the numerical aperture for the first direction of the beam incident to the irradiated body NA _y, the irradiated body When the spherical aberration for the first direction of the beam to be projected and the spherical aberrations of the S _1, the second direction in S _2, the first lens element and the second lens member, S ₁ <λ / NA _y ² and the condition that S ₂ <λ / NA _x ² and the condition that | S ₁ -S ₂ | <λ / NA _y ² and | S ₁ -S ₂ | <λ / NA _x ² Condition is satisfied.

According to a fourth aspect of the present invention, there is provided a method of scanning a patterning beam along a main scanning direction on a workpiece in a one-dimensional scanning manner and relatively moving the workpiece and the beam in a sub scanning direction crossing the main scanning direction, A beam drawing apparatus for drawing a pattern on a carcass, comprising: a beam generating device for generating the beam; a beam expander for converting the beam from the beam generating device into a parallel beam expanded in beam diameter; A main scanning optical system for focusing the spot of the beam on the object to be scanned by incidence of the one-dimensional deflected beam, and a scanning optical system for scanning the one- And a beam deflecting member provided between the beam expander and the beam deflecting member, for entering the beam converted by the beam expander, A first optical system including a first optical element having an anisotropic refracting power for converging the projected beam in a direction corresponding to the sub scanning direction, and a second optical system for projecting the beam, which is emitted from the main use optical system, A second optical system including a second optical element having an anisotropic refractive power for converging in a sub-scanning direction; a second optical system provided in an optical path of the beam expander, for shifting the optical path of the beam in a direction corresponding to the sub- And an optical member.

BRIEF DESCRIPTION OF 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 an embodiment; FIG.
Fig. 2 shows a schematic configuration of the beam switching unit and the imaging head shown in Fig. 1, and shows the arrangement relationship of the scanning lines of the respective scanning units of the imaging head on the substrate.
Fig. 3 is a view showing a specific configuration around the optical element for selection and the incidence mirror of the beam switching section shown in Fig. 2; Fig.
Fig. 4 is a view showing a specific configuration of the scanning unit shown in Fig. 2, and is a view seen from a plane (XZ plane) orthogonal to a plane (plane parallel to the XY plane) including the scanning direction (deflection direction) of the beam.
Fig. 5 is a schematic view of the beam from the aperture stop shown in Fig. 4 to the substrate viewed from a plane parallel to the plane including the deflection direction (main scanning direction) of the beam.
6 is a view showing lens data in an optical design example according to Comparative Example 1. Fig.
7 is a schematic view of the state of the beam from the beam expander to the substrate (the image surface) in a plane parallel to the plane including the deflection direction of the beam (the main scanning direction of the spot light) in Comparative Example 1. Fig.
8 is a schematic view of the state of the beam from the beam expander shown in Fig. 7 to the reflecting surface of the polygon mirror, as viewed from a plane orthogonal to the main scanning direction of the beam.
Fig. 9 is a schematic view of the state of the beam from the reflection surface of the polygon mirror shown in Fig. 7 to the substrate (upper surface) as viewed from a plane perpendicular to the main scanning direction of the beam.
Fig. 10 is an explanatory view for explaining the generation state of spherical aberration in the main-scan direction of a beam projected from the f? Lens system onto the substrate (upper surface).
11 is a diagram for explaining exaggerated state of the spherical aberration in the sub-scan direction of the beam projected from the f? Lens system onto the substrate (upper surface).
12 is a graph simulating the spherical aberration characteristics in the main scanning direction and the sub scanning direction of the beam generated by the optical design example of the first comparative example.
13 is a graph showing the spherical aberration characteristics of the difference between the spherical aberration in the main scanning direction and the spherical aberration in the sub-scanning direction in Comparative Example 1. Fig.
14 is a diagram showing lens data in the optical design example according to the first embodiment.
15 is a schematic view showing the state of the beam from the beam expander to the substrate (upper surface) in Embodiment 1 in a plane parallel to the plane including the deflection direction of the beam (the main scanning direction of the spot light).
16 is a schematic view showing the state of the beam from the beam expander shown in Fig. 15 to the reflecting surface of the polygon mirror, in a plane perpendicular to the main scanning direction of the beam.
FIG. 17 is a schematic view of the state of the beam from the reflection surface of the polygon mirror shown in FIG. 15 to the substrate (upper surface), in a plane orthogonal to the main scanning direction of the beam.
18 is a graph simulating the spherical aberration characteristics in the main scanning direction and the sub scanning direction of the beam generated by the optical design example of the first embodiment.
19 is a graph showing the spherical aberration characteristics of the difference between the spherical aberration in the main scanning direction and the spherical aberration in the sub scanning direction in the first embodiment.
20A is a view showing a state in which a parallel flat plate is not inclined in the XZ plane, and FIG. 20B is a view showing a state in which the parallel flat plate is inclined by an angle? With respect to the YZ plane.

A preferred embodiment of a beam scanning apparatus and a drawing apparatus according to the present invention will be described with reference to the accompanying drawings. It is to be understood that the present invention is not limited to these embodiments, but includes various modifications and improvements. That is, the constituent elements described below include those that can be easily assumed by those skilled in the art, substantially the same, and the constituent elements described below can be appropriately combined. In addition, various omissions, substitutions or alterations of the constituent elements can be made without departing from the gist of the present invention.

[First Embodiment]

1 is a view showing a schematic configuration of a device manufacturing system 10 including an exposure apparatus EX for performing exposure processing on a substrate (object to be irradiated) P of the first embodiment. In the following description, an XYZ orthogonal coordinate system in which the gravity direction is the Z direction is set, unless otherwise stated, and the X direction, the Y direction, and the Z direction will be described along the arrows in the drawing.

The device manufacturing system 10 is a system (substrate processing apparatus) for producing an electronic device by performing a predetermined process (such as exposure process) on the substrate P. The device manufacturing system 10 is a manufacturing line for manufacturing, for example, a flexible display as an electronic device, a film-shaped touch panel, a film-like color filter for a liquid crystal display panel, a flexible wiring, or a flexible sensor It is a constructed manufacturing system. Hereinafter, a flexible display is assumed as an electronic device. Examples of the flexible display include an organic EL display, a liquid crystal display, and the like. The device manufacturing system 10 is a system in which a substrate P is fed out from a feeding roll (not shown) in which a sheet-like substrate (sheet substrate) P of a flexible (flexible) Called roll-to-roll system in which various treatments are continuously performed on the substrate P after the various treatments and the substrate P after the various treatments is taken up on a recovery roll (not shown). Therefore, the substrate P after various treatments is in a state in which a plurality of devices are connected to each other in the conveying direction of the substrate P, and is a substrate for multi-face picking. The substrate P sent from the supply roll is sequentially subjected to various treatments in the process apparatus PR1, the exposure apparatus EX, and the process apparatus PR2, and is wound on the collecting roll. The substrate P has a band-like shape in which the moving direction (conveying direction) of the substrate P is long (long) and the width direction is short (long) I have.

In the first embodiment, the X direction is a direction in which the substrate P is directed from the supply roll toward the recovery roll in a horizontal plane orthogonal to the Z direction. The Y direction is a direction orthogonal to the X direction within a horizontal plane orthogonal to the Z direction, and is a width direction (short direction) of the substrate P. [ The -Z direction is a direction in which gravity acts (gravity direction), and the carrying direction of the substrate P is a + X direction.

As the substrate P, for example, a resin film, a foil (foil) made of a metal such as stainless steel or an alloy, or the like is used. Examples of the material of the resin film include polyethylene resin, polypropylene resin, polyester resin, ethylene vinyl copolymer resin, polyvinyl chloride resin, cellulose resin, polyamide resin, polyimide resin, polycarbonate resin, polystyrene resin, And vinyl acetate resin may be used. The thickness and the rigidity (Young's modulus) of the substrate P are set such that when the substrate P passes through the conveying path of the device manufacturing system 10, folded gold or irreversible wrinkles due to buckling do not occur on the substrate P Range. As the base material of the substrate P, a film of PET (polyethylene terephthalate) or PEN (polyethylene naphthalate) having a thickness of about 25 to 200 mu m is a typical example of a sheet substrate.

Since the substrate P sometimes receives heat in each process performed in the device manufacturing system 10, it is preferable to select the substrate P having a material with a remarkably small thermal expansion coefficient. For example, the thermal expansion coefficient can be suppressed by mixing the inorganic filler with the resin film. The inorganic filler may be, for example, titanium oxide, zinc oxide, alumina, silicon oxide or the like. The substrate P may be a very thin glass single layer having a thickness of about 100 mu m produced by a float method or the like and may be a laminate obtained by bonding the above resin film or foil to the extremely thin glass.

The flexibility of the substrate P can be obtained by bending the substrate P without shearing or breaking the substrate P by applying a force of about its own weight It says nature. Also, the property of flexing by the force of the degree of self weight is included in flexibility. The degree of flexibility changes depending on the material, size and thickness of the substrate P, the layer structure formed on the substrate P, the temperature, the environment such as humidity, and the like. As a result, when the substrate P is properly wound on the conveying direction switching member such as various conveying rollers and rotary drums provided in the conveying path in the device manufacturing system 10 according to the first embodiment, If the substrate P can be smoothly transported without cracks or breakage (breakage or cracks occurring), the range of flexibility can be said.

The process apparatus (processing apparatus) PR1 conveys the substrate P sent from the supply roll toward the exposure apparatus EX at a predetermined speed in the transport direction (+ X direction) along the long direction, EX to the substrate P to be processed. The substrate P to be sent to the exposure apparatus EX by the major definition processing is a substrate (photosensitive substrate) having a photosensitive functional layer (photosensitive layer) formed on its surface.

This photosensitive functional layer is applied onto the substrate P as a solution and becomes a layer (film) by drying. A typical example of the photosensitive functional layer is a photoresist (liquid or dry film), but it is a material which does not require a developing process and is a material having a hydrophilic property A photosensitive silane coupling agent (SAM), in which a plating reductant is exposed at the 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 by ultraviolet rays on the substrate P is modified from lyophobic to lyophilic. Therefore, by selectively applying a conductive ink (ink containing conductive nanoparticles such as silver or copper) or a liquid containing a semiconductor material onto the lyophilic area, an electrode constituting a thin film transistor (TFT) or the like, It is possible to form a pattern layer to be a semiconductor, insulating, or connection wiring. When a photosensitive reductant is used as the photosensitive functional layer, a plating reductant is exposed to a pattern portion exposed by ultraviolet rays on the substrate P. Therefore, after the exposure, the substrate P is immediately immersed (immersed) in the plating solution containing palladium ions for a predetermined time to form (precipitate) a pattern layer of palladium. Such a plating process is an additive process, but it is also possible to assume an etching process as a subtractive process. In this case, the substrate P to be sent to the exposure apparatus EX can be made of PET or PEN, and a metallic thin film such as aluminum (Al) or copper (Cu) And a photoresist layer is further laminated thereon.

The exposure apparatus (processing apparatus) EX transfers the substrate P transported from the processing apparatus PR1 toward the processing apparatus PR2 at a predetermined speed in the transport direction (+ X direction) In the exposure apparatus. The exposure apparatus EX exposes a pattern for an electronic device (for example, a pattern of an electrode or a wiring of a TFT constituting an electronic device) on the surface of the substrate P (the surface of the photosensitive functional layer, Is irradiated. As a result, a latent image (modified portion) corresponding to the pattern is formed on the photosensitive functional layer.

In the first embodiment, the exposure apparatus EX is an exposure apparatus of a direct drawing type without using a mask, or an exposure apparatus (drawing apparatus) of a so-called raster scan type. The exposure apparatus EX conveys the spotlight SP of the beam LB (pulse beam) for exposure in pulse form to the irradiated surface of the substrate P while conveying the substrate P in the + X direction (ON / OFF) in accordance with the pattern data (imaging data, pattern information) while scanning (main scanning) the spot light SP in a predetermined scanning direction (Y direction) do. Thus, a light pattern corresponding to a predetermined pattern such as an electronic device, a circuit, or a wiring is drawn and exposed on the surface to be irradiated of the substrate P. That is, the spot light SP is relatively two-dimensionally scanned on the surface to be irradiated (the surface of the photosensitive functional layer) of the substrate P by the sub-scanning of the substrate P and the main scanning of the spot light SP, P, a predetermined pattern is drawn and exposed. Since the substrate P is transported along the transport direction (+ X direction), the exposure area in which the pattern is exposed by the exposure apparatus EX is divided into a plurality of . Since the electronic device is formed in this exposure area, the exposure area is also a device formation area.

The process apparatus (processing apparatus) PR2 transfers the substrate P sent from the exposure apparatus EX toward the collecting roll in the conveying direction (+ X direction) along the long direction at a predetermined speed, (For example, a plating process, a developing process, an etching process, or the like) is performed on the substrate P subjected to the exposure process in the exposure process EX. A pattern layer of the device is formed on the substrate P by the subsequent process.

Next, the exposure apparatus EX will be described in more detail with reference to Figs. 2 to 5. Fig. The exposure apparatus EX is stored in a temperature adjusting and temperature control chamber (ECV) as shown in Fig. By maintaining the inside of the temperature-controlled chamber (ECV) at a predetermined temperature and a predetermined humidity, it is possible to suppress the change in the shape due to the temperature of the substrate (P) conveyed in the inside thereof, This suppresses the charging of the static electricity generated. The temperature control chamber (ECV) is disposed on the mounting surface (E) of the manufacturing factory through passive or active vibration isolating units (SU1, SU2). The vibration damping units SU1 and SU2 reduce the vibration from the mounting surface E. The mounting surface (E) may be a floor surface (pedestal) on which the floor surface of the factory itself is fine, and which is installed exclusively on the floor surface to form a horizontal surface. The exposure apparatus EX includes at least a substrate transport mechanism 12, a light source device 14, a beam switching unit (BDU), a drawing head 16, and a control device 18. [ The control device 18 controls each section of the exposure apparatus EX. The control device 18 includes a computer and a recording medium on which a program is recorded. The control device 18 functions as the control device 18 of the first embodiment by executing the program.

The substrate transport mechanism 12 constitutes a part of the substrate transport apparatus of the device manufacturing system 10 and transports the substrate P transported from the process apparatus PR1 in the exposure apparatus EX at a predetermined speed And sends it to the processing apparatus PR2 at a predetermined speed. The substrate conveying mechanism 12 sequentially forms an edge position controller EPC, a driving roller R1, a tension adjusting roller RT1, a rotary drum R1, (Cylindrical drum) DR, a tension adjusting roller RT2, a driving roller R2, and a driving roller R3. The substrate P hangs over the edge position controller EPC, the drive rollers R1 to R3, the tension adjustment rollers RT1 and RT2 and the rotary drum (cylindrical drum) DR of the substrate transport mechanism 12 The transport path of the substrate P transported in the exposure apparatus EX is defined.

The edge position controller (EPC) adjusts the position in the width direction of the substrate P conveyed from the process apparatus PR1 (in the direction of the short side of the substrate P in the Y direction). That is, the edge position controller (EPC) controls the position of the edge of the substrate P in the width direction of the substrate P, which is transported in a predetermined tension, within a range of about 占 퐉 to about 占 퐉 The substrate P is moved in the width direction so as to adjust the position in the width direction of the substrate P so as to be within the predetermined range (allowable range). The edge position controller EPC includes a roller on which the substrate P is wound with a predetermined tension applied thereto and an edge sensor (not shown) for detecting the position of the edge (edge) Detection section). 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 to adjust the position in the width direction of the substrate (P). The driving 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 rotary drum DR . The edge position controller EPC controls the width of the substrate P so that the longitudinal direction of the substrate P wound around the rotary drum DR is always orthogonal to the central axis AXo of the rotary drum DR. And the parallelism of the roller axis and the Y axis of the edge position controller EPC may be adjusted appropriately so as to correct the tilting error in the traveling direction of the substrate P. [

The rotary drum DR has a central axis AXo extending in the Y direction and a direction intersecting the direction in which gravity acts and a cylindrical outer peripheral surface having a certain radius from the central axis AXo. The rotary drum DR rotates about the central axis AXo and rotates about the central axis AXo while curving and holding (maintaining) a part of the substrate P along the outer peripheral surface ) In the + X direction (long direction). The rotary drum DR supports an area (portion) on the substrate P on which the beam LB (spot light SP) from the imaging head 16 is projected, from its outer peripheral surface. The rotary drum DR supports (holds and maintains) the substrate P from the side (back side) opposite to the side (side on which the photosensitive surface is formed) on which the electronic device is formed. On both sides of the rotary drum DR in the Y direction, a shaft Sft is provided which is supported by an annular bearing so that the rotary drum DR rotates around the central axis AXo. The rotation drum DR is provided with a rotation torque from a rotation drive source (not shown) (for example, a motor or a deceleration mechanism) controlled by the control device 18 to the shaft Sft, To rotate at a constant rotation speed. For convenience, a plane including the central axis AXo and parallel to the YZ plane is referred to as a center plane Poc.

The driving rollers (nip rollers) R2 and R3 are arranged at predetermined intervals along the conveying direction (+ X direction) of the substrate P, and the substrate P after the exposure has a predetermined looseness Free). The driving rollers R2 and R3 rotate while holding the front and back surfaces of the substrate P in the same manner as the driving roller R1 and transport the substrate P toward the processing device PR2. The tension adjustment rollers RT1 and RT2 are pressed in the -Z direction and apply a predetermined tension to the substrate P held on the rotary drum DR and supported thereon in the longitudinal direction. As a result, the tension in the longitudinal direction applied to the substrate P held by the rotary drum DR is stabilized within a predetermined range. The control device 18 rotates the drive rollers R1 to R3 by controlling a rotation drive source (not shown) (for example, a motor or a deceleration mechanism). 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 rotary drum DR.

The light source device 14 generates and emits a pulse beam (pulse beam, pulse light, laser) LB. The beam LB is ultraviolet light having a peak wavelength in a wavelength band of 370 nm or less and the light emission frequency (oscillation frequency, predetermined frequency) of the beam LB is Fa. The beam LB emitted by the light source device 14 enters the imaging head 16 through the beam switching unit BDU. The light source device 14 emits and emits the beam LB at the light emission frequency Fa under the control of the control device 18. [ The light source device 14 includes a semiconductor laser device for generating pulsed light in the infrared wavelength range, a fiber amplifier, and a wavelength conversion element for converting the pulse light in the amplified infrared wavelength range into pulse light in the ultraviolet wavelength range ) Or the like may be used. By constituting the light source device 14 as described above, ultraviolet pulse light having an oscillation frequency Fa of several hundreds of MHz and a high luminance of about one picosecond of light emission time of one pulse light is obtained. It is assumed that the beam LB emitted from the emission window of the light source device 14 has a narrow parallel beam whose beam diameter is about 1 mm or less.

2, the beam switching unit BDU includes a plurality of scanning units Un (n = 1, 2, ..., 6) constituting the imaging head 16 And has a plurality of optical switching elements for switching the beam LB to enter the scanning unit Un in a time-divisional manner (time-divisional). The plurality of switching elements successively switches the scanning unit Un to which the beam LB enters from among the scanning units U1 to U6. For example, the beam switching unit BDU repeats the switching of the scanning unit Un to which the beam LB enters, in the order of U1? U2? U3? U4? U5? U6. The beam LB from the light source device 14 incident on the scanning unit Un through the beam switching unit BDU may be denoted by LBn. The beam LBn incident on the scanning unit U1 is represented by LB1 and the beams LBn incident on each of the scanning units U2 through U6 are represented by LB2 through LB6.

As shown in Fig. 2, each of the scanning units U1 to U6 is provided with a polygon mirror PM for main scanning the incident on-beams LB1 to LB6. In the first embodiment, each of the polygon mirrors PM of each scanning unit Un is synchronously controlled so as to maintain a constant rotation angle phase with each other while being precisely rotated at the same rotation speed. Thereby, the timings (main scanning periods of the spot lights SP) of the respective main scanning lines of the beams LB1 to LB6 projected from the scanning units U1 to U6 onto the substrate P are set so as not to overlap each other . Therefore, the beam switching unit BDU switches the beam LB to any one of the scanning units Un so that the beam LB is incident on any one of the scanning units Un for scanning the spot light SP It is possible to divide the beam LB by time division. The scanning unit Un (the scanning unit Un to which the beam LBn enters) for performing the main scanning of the spot light SP is composed of U1? U2? U3? U4? U5? U6? U1 ... . A configuration for dividing the beam LB from the light source device 14 into the plurality of scan units Un in a time division manner is disclosed in International Publication No. 2015/166910 pamphlet.

As shown in Fig. 2, the imaging head 16 is a so-called multi-beam type imaging head in which a plurality of scanning units Un (U1 to U6) having the same arrangement 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 rotary drum DR by the plurality of scanning units Un (U1 to U6). Each of the scanning units Un (U1 to U6) projects on the substrate P while projecting the beam LBn from the beam switching unit BDU onto the substrate P (on the surface to be irradiated on the substrate P) And converges (converges) the beam LBn. As a result, the beams LBn (LB1 to LB6) projected onto the substrate P become spot lights SP. The rotation of the polygon mirror PM of each of the scanning units Un (U1 to U6) causes the spot light SP of the beams LBn (LB1 to LB6) projected on the substrate P to converge in the main scanning direction (Y direction). A linear drawing line (scan line) SLn (n = 1, 2, ...) on which a pattern of one line minute is drawn is formed on the substrate P by the scanning of the spot light SP. , 6) are defined. That is, the drawing line SLn indicates a scan locus on the substrate P of the spot light SP of the beam LBn.

The scanning unit U1 scans the spotlight SP along the drawing line SL1 and similarly the scanning units U2 to U6 scan the spot light SP along the drawing lines SL2 to SL6 do. 2, the drawing lines SLn (SL1 to SL6) of the plurality of scanning units Un (U1 to U6) are connected to a rotary drum (not shown) via a center plane Poc DR in a zigzag arrangement in two rows in the circumferential direction. The odd-numbered drawing lines SL1, SL3 and SL5 are located on the surface to be processed of the substrate P on the upstream side (-X direction side) in the carrying direction of the substrate P with respect to the center plane Poc, , And are arranged in one row at predetermined intervals along the Y direction. The even-numbered drawing lines SL2, SL4 and SL6 are located on the surface to be irradiated of the substrate P on the downstream side (+ X direction side) in the carrying direction of the substrate P with respect to the center plane Poc, And are arranged in one row at predetermined intervals along the Y direction.

Therefore, the plurality of scanning units Un (U1 to U6) are also arranged in a zigzag arrangement in two rows in the conveying direction of the substrate P with the central plane Poc therebetween. That is, the odd-numbered scanning units U1, U3, and U5 are arranged on the upstream side (-X direction side) in the transport direction of the substrate P with respect to the center plane Poc, As shown in FIG. The even-numbered scanning units U2, U4 and U6 are arranged downstream in the conveying direction of the substrate P with respect to the center plane Poc (in the + X direction) . The odd-numbered scanning units U1, U3, and U5 and the even-numbered scanning units U2, U4, and U6 are provided symmetrically with respect to the center plane Poc as viewed from the XZ plane.

Although the odd-numbered writing lines SL1, SL3 and SL5 and the even-numbered writing lines SL2, SL4 and SL6 are separated from each other in the X direction (carrying direction of the substrate P) (The width direction of the recording medium P, the main scanning direction) are set so as to be connected with each other without being separated from each other. The drawing lines SL1 to SL6 are substantially parallel to the width direction of the substrate P, that is, the central axis AXo of the rotary drum DR. The connection of the drawing lines SLn in the Y direction means that the ends of the drawing line SLn are adjacent or partially overlapped with each other in the Y direction. In the case of overlapping the end portions of the drawing line SLn, for example, if the length of each drawing line SLn is overlapped in the range of several percent or less in the Y direction including the drawing start point or the drawing end point good.

As described above, 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) covers the entire width direction of the exposure area. Thus, each of the scanning units Un (U1 to U6) can draw a pattern for each of a plurality of regions (drawing regions) divided in the width direction of the substrate P. [ For example, when the scanning length in the Y direction (the length of the drawing line SLn) by one scanning unit Un is about 20 to 60 mm, three odd-numbered scanning units U1, U3 and U5, The width of the Y-direction in which the image can be drawn is widened to about 120 to 360 mm by arranging a total of six scanning units Un with three scanning units U2, U4 and U6 in the Y direction. The length of each drawing line SLn (SL1 to SL6) (the length of the drawing range) is basically the same. In other words, the scanning distance of the spot light SP of the beam LBn scanned along each of the rendering lines SL1 to SL6 is basically the same.

Since the beam LB from the light source device 14 is a pulse light, the spot light SP projected onto the imaging line SLn during the main scanning is incident on the beam LB of the beam LB, And become discrete according to the frequency Fa (for example, 400 MHz). Therefore, it is necessary to overlap the spot light SP projected by the one pulse light of the beam LB and the spot light SP projected by the next one pulse light in the main scanning direction. The amount of the overlap is set by the size? Of the spot light SP, the scanning speed (main scanning speed) Vs of the spot light SP, and the oscillation frequency Fa of the beam LB. The effective size (diameter)? Of the spot light SP is 1 / e ² (the diameter) of the peak intensity of the spot light SP when the intensity distribution of the spot light SP is approximated by a Gaussian distribution (Or 1/2) of the width dimension. In the first embodiment, the scanning speed Vs of the spot light SP (the rotation speed of the polygon mirror PM) is set so that the spot light SP of about × x 遜 is overlapped with the effective size (dimension) ) And the oscillation frequency Fa are set. Therefore, the projection interval of the pulse-like spot light SP along the main-scan direction becomes? / 2. Therefore, also in regard to the sub-scanning direction (the direction orthogonal to the drawing line SLn), between the scanning of the spot light SP along the drawing line SLn and the next scanning, Is set to move by a distance of about 1/2 of the effective size? Of the spot light SP. In addition, in the case of connecting the drawing lines SLn adjacent to each other in the Y direction in the main scanning direction, it is also preferable to overlap the drawing lines SLn by? / 2. In the first embodiment, the size (dimension)? Of the spot light SP is set to about 3 占 퐉.

Each of the scanning units Un (U1 to U6) forms each beam LBn on the substrate P so that each beam LBn advances toward the central axis AXo of the rotary drum DR, . Thus, the optical path (beam central axis) of the beam LBn traveling from each of the scanning units Un (U1 to U6) toward the substrate P is perpendicular to the normal to the surface to be irradiated of the substrate P . At this time, with respect to the XZ plane, the moving direction of the beam LB projected from the odd-numbered scanning units U1, U3 and U5 toward the substrate P (the drawing lines SL1, SL3 and SL5) The direction of the beam LB projected from the even-numbered scanning units U2, U4, U6 toward the substrate P is set to -θ1, And the angle between the central plane Poc and the drawing lines SL2, SL4 and SL6 and the central axis AXo is +? 1. That is, with respect to the XZ plane, the direction of travel of the beam LB projected from the odd-numbered scanning units U1, U3, U5 toward the substrate P and the traveling direction of the beam LB projected from the even-numbered scanning units U2, U4, U6 The traveling direction of the beam projected toward the substrate P is symmetrical with respect to the center plane Poc. The scanning units Un (U1 to U6) are arranged in such a manner that the beam LBn irradiating the drawing lines SLn (SL1 to SL6) is inclined with respect to the surface to be irradiated of the substrate P in the plane parallel to the YZ plane And the beam LBn is irradiated toward the substrate P so as to be vertical. That is, with respect to the main scanning direction of the spot light SP on the surface to be irradiated, the beams LBn (LB1 to LB6) projected onto the substrate P are scanned in the telecentric state.

The configuration of the beam switching unit BDU and the scanning units Un (U1 to U6) of the writing head 16 will be briefly described with reference to Fig. The beam switching unit BDU includes selection optical elements AOMn (AOM1 to AOM6) as a plurality of switching elements, a plurality of reflection mirrors M1 to M12, a plurality of incident mirrors IMn (IM1 to IM6) And an absorber TR. The optical elements for selection (AOMn (AOM1 to AOM6)) are transparent to the beam LB and are acousto-optic modulators (AOM) driven by ultrasonic signals. The plurality of selection optical elements AOMn (AOM1 to AOM6) and the plurality of incident mirrors IMn (IM1 to IM6) are provided corresponding to the plurality of scanning units Un (U1 to U6). For example, the selection optical element AOM1 and the entrance mirror IM1 are provided corresponding to the scanning unit U1, and similarly, the selection optical elements AOM2 to AOM6 and the entrance mirrors IM2 to IM6 , And scanning units U2 to U6.

The light beam LB from the light source device 14 is bent in the shape of a meandering beam by the reflecting mirrors M1 to M12 and guided to the absorber TR. Hereinafter, the case in which all of the optical elements for selection (AOMn (AOM1 to AOM6)) are off (a state in which no ultrasonic signal is applied) will be described in detail. Although not shown in Fig. 2, a plurality of lenses are provided in the beam path from the reflecting mirror M1 to the absorber TR, and a plurality of lenses are provided so as to converge the beams LB from the parallel beams, ) To the parallel light flux. The constitution will be described later with reference to Fig.

2, the beam LB from the light source device 14 travels in the -X direction parallel to the X-axis and enters the reflecting mirror M1. The beam LB reflected from the reflecting mirror M1 in the -Y direction enters the reflecting mirror M2. The beam LB reflected from the reflecting mirror M2 in the + X direction passes through the selecting optical element AOM5 straightly and reaches the reflecting mirror M3. The beam LB reflected from the reflecting mirror M3 in the -Y direction enters the reflecting mirror M4. The beam LB reflected from the reflecting mirror M4 in the -X direction passes straight through the optical element for selection AOM6 and reaches the reflecting mirror M5. The beam LB reflected from the reflecting mirror M5 in the -Y direction enters the reflecting mirror M6. The beam LB reflected from the reflecting mirror M6 in the + X direction passes through the selecting optical element AOM3 straightly and reaches the reflecting mirror M7. The beam LB reflected from the reflecting mirror M7 in the -Y direction enters the reflecting mirror M8. The beam LB reflected from the reflecting mirror M8 in the -X direction passes straight through the optical element for selection AOM4 and reaches the reflecting mirror M9. The beam LB reflected from the reflecting mirror M9 in the -Y direction enters the reflecting mirror M10. The beam LB reflected from the reflecting mirror M10 in the + X direction passes straight through the optical element for selection AOM1 and reaches the reflecting mirror M11. The beam LB reflected from the reflecting mirror M11 in the -Y direction enters the reflecting mirror M12. The beam LB reflected from the reflecting mirror M12 in the -X direction passes straight through the optical element for selection AOM2 and is guided to the absorber TR. The absorber TR is a light trap that absorbs the beam LB to suppress leakage of the beam LB to the outside.

When each of the optical elements for selection AOMn is irradiated with the first-order diffracted light obtained by diffracting the incident beam (zero order light) LB at a diffraction angle corresponding to the frequency of the high frequency, (Beam LBn). Therefore, the beam emitted as first-order diffracted light from the optical element for selection AOM1 becomes LB1, and the beams emitted as first-order diffracted light from the selection optical elements AOM2 to AOM6 become LB2 to LB6. Thus, each of the selection optical elements AOMn (AOM1 to AOM6) has a function of deflecting the optical path of the beam LB from the light source device 14. [ However, since the actual acoustooptic modulating element generates the first-order diffracted light by about 80% of the zero-th order light, the beams LBn (LB1 to LB6) deflected in each of the optical elements for selection AOMn (AOM1 to AOM6) ) Is lower than the intensity of the original beam LB. When any one of the optical elements for selection (AOMn (AOM1 to AOM6)) is in the on state, approximately 0% of the zero-order light remaining without diffraction remains, and it is finally absorbed by the absorber TR.

Each of the plurality of selection optical elements AOMn (AOM1 to AOM6) is provided so as to deflect beams LBn (LB1 to LB6), which are deflected first order diffracted light, in the -Z direction with respect to the incident beam LB . The beams LBn (LB1 to LB6) deflected and emitted from each of the optical elements for selection (AOMn (AOM1 to AOM6)) are positioned at a predetermined distance from each of the optical elements for selection AOMn (AOM1 to AOM6) IMn (IM1 to IM6) provided on the incident mirror IMn. Each of the incident mirrors IMn to IM6 reflects the incident beams LBn (LB1 to LB6) in the -Z direction so that the beams LBn (LB1 to LB6) To U6). Each of the incident mirrors IMn is also referred to as a light use mirror because each of the beams LBn is projected in the -Z direction.

The same configuration, function, action, and the like of the optical elements for selection (AOMn (AOM1 to AOM6)) may be used. The plurality of optical elements for selection (AOMn (AOM1 to AOM6)) are arranged so that the generation of the diffracted light obtained by diffracting the incident beam (LB) is switched on and off according to the ON / OFF of the drive signal (high frequency signal) / Off. For example, when the drive signal (high-frequency signal) from the control device 18 is not applied and the optical element AOM5 is in the OFF state, the optical element AOM5 selects the beam LB from the incident light source device 14 It is transmitted without being diffracted. Therefore, the beam LB transmitted through the selection optical element AOM5 is incident on the reflection mirror M3. On the other hand, when the driving signal (high-frequency signal) from the control device 18 is applied, the optical element for selection AOM5 diffracts the incident beam LB to direct the incident mirror IM5 . That is, the selection optical element AOM6 switches by this drive signal. In this way, by switching each optical element for selection AOMn, the beam LBn can be guided to any one of the scanning units Un, and the scanning unit Un to which the beam LBn is incident You can switch.

The control device 18 shown in Fig. 1 controls on / off of the pulsed beam LB projected from the light source device 14 on the basis of the pattern data (drawing data) according to the pattern to be drawn . A configuration in which the pulsed beam LB from the light source device 14 is turned on / off (modulated) based on the pattern data in the case where the light source device 14 is a fiber amplifier laser light source, 2015/166910. &Lt; / RTI &gt; Here, the pattern data will be briefly described. The pattern data (drawing data, design information) is provided for each scanning unit Un, and the pattern drawn by each scanning unit Un is divided by pixels of dimensions set according to the size of the spot light SP , And each of the plurality of pixels is represented by logical information (pixel data) in accordance with a pattern to be drawn. That is, this pattern data is obtained by arranging the direction along the main scanning direction (Y direction) of the spot light SP as a row direction and the direction along the sub-scanning direction (X direction) ) Direction of the pixel, as shown in Fig. The logic information of this pixel is data of one bit of "0" or "1". The logic information of &quot; 0 &quot; means that the intensity of the spot light SP to be irradiated on the substrate P is made low (non-rendering), and the logic information of &quot; 1 &quot; Means that the intensity of the spot light SP is set to a high level (drawing).

The logical information of one column (minute) of the pattern data corresponds to one drawing line SLn (SL1 to SL6). Therefore, the number of pixels in one column is determined by the dimension of the pixel on the surface to be processed of the substrate P and the length of the drawing line SLn. The dimension Pxy of the one pixel is set to be equal to or larger than the size? Of the spot light SP. For example, when the effective size? Of the spot light SP is 3 占 퐉, The dimension Pxy is set to be equal to or larger than about 3 占 퐉 (one side length of a corner or a square). The intensity of the spot light SP projected onto the substrate P is modulated along one drawing line SLn (SL1 to SL6) in accordance with the logic information of the pixels in one column. In the case where the light source device 14 is a fiber amplifier laser light source, as disclosed in International Publication No. 2015/166910 pamphlet, the pulse-like seed light (emission frequency Fa) in the infrared wavelength region incident on the fiber amplifier 1 "and" 0 "of the pixel of the pattern data sent from the control device 18, the pulse light having high peak intensity and sharp peak, and the pulse light having low peak intensity and gentle pulse light, Lt; / RTI &gt;

When the diameter of the beam LB incident on the selection optical element AOMn is small, the selection optical element AOMn has high diffraction efficiency and responsiveness. For this reason, when the beam LB incident on the selection optical element AOMn is made to be a parallel beam, the beam LB incident on the selection optical element AOMn is reduced in the parallel beam state A shaping optical system may be provided. In the first embodiment, since the diameter of the beam LB emitted from the light source device 14 is a parallel light flux of 1 mm or less, it can pass through the optical element for selection AOMn without change.

2 and 3, the light source unit 14 and the beam switching unit BDU constitute a beam supplying unit (beam generating device) for supplying the imaging beam LBn to each of the scanning units Un do. The beam supply unit for the scanning unit U5 in Fig. 2 is constituted by the light source device 14, the mirrors M1 and M2, the optical element for selection AOM5 and the entrance mirror IM5 And the beam supply unit for the scanning unit U6 is constituted by the light source device 14, the mirrors M1 to M4, the selection optical elements AOM5 and AOM6 and the entrance mirror IM6, U3 are constituted by the light source device 14, the mirrors M1 to M6, the optical elements for selection AOM5, AOM6 and AOM3, and the entrance mirror IM3, The beam-supplying unit is composed of a light source unit 14, mirrors M1 to M8, optical elements for selection AOM5, AOM6, AOM3 and AOM4, and an incident mirror IM4, The beam supply unit is constituted by the light source device 14, the mirrors M1 to M10, the selection optical elements AOM5, AOM6, AOM3, AOM4 and AOM1 and the incident mirror IM1, ) Includes a light source unit 14, mirrors M1 to M12, a selection optical unit (AOM5, AOM6, AOM3, AOM4, AOM1, AOM2), and an incident mirror IM2.

Next, the configuration of the scanning unit (beam scanning device) Un will be described. Since each of the scanning units Un (U1 to U6) has the same configuration, only the scanning unit U1 will be described briefly. The scanning unit U1 includes at least the reflecting mirrors M20 to M24, the polygon mirror PM, and the f? Lens system FT. 2, a first cylindrical lens CY1 is disposed immediately before the polygon mirror PM as viewed from the direction in which the beam LB1 travels, and a second cylindrical lens CY1 is disposed behind the f lens system FT, A dichroic lens CY2 is provided. The first cylindrical lens CY1 and the second cylindrical lens CY2 will be described later in detail with reference to FIG.

The beam LB1 reflected from the incident mirror IM1 in the -Z direction is incident on the reflecting mirror M20 and the beam LB1 reflected by the reflecting mirror M20 travels in the -X direction, M21. The beam LB1 reflected by the reflecting mirror M21 in the -Z direction is incident on the reflecting mirror M22 and the beam LB1 reflected by the reflecting mirror M22 travels in the + ). The reflecting mirror M23 reflects the incident beam LB1 toward the reflecting surface RP of the polygon mirror PM.

The polygon mirror PM reflects the incident beam LB1 toward the +? Direction toward the f? Lens system FT. The polygon mirror PM deflects the incident beam LB1 in one dimension in a plane parallel to the XY plane since the spot light SP of the beam LB1 is scanned on the surface to be irradiated on the substrate P )do. More specifically, the polygon mirror (rotary polygon mirror, movable deflection member) PM includes a rotation axis AXp extending in the Z-axis direction, a plurality of reflection surfaces RP formed around the rotation axis AXp In the embodiment, the number Np of reflecting surfaces RP is 8). The reflection angle of the pulse beam LB1 irradiated on the reflection surface RP can be continuously changed by rotating the polygon mirror PM around the rotation axis AXp in the predetermined rotation direction. As a result, the beam LB1 is deflected by one reflecting surface RP and the spot light SP of the beam LB1 irradiated onto the surface to be irradiated on the substrate P is irradiated in the main scanning direction (the substrate P) In the width direction, Y direction). That is, the spot light SP of the beam LB1 can be scanned along the main scanning direction by one reflecting surface RP. Therefore, the number of the imaging lines SL1 in which the spot light SP is scanned on the surface to be irradiated of the substrate P by one rotation of the polygon mirror PM is equal to the number of the reflecting surfaces RP at the maximum 8. The polygon mirror PM is accurately rotated at a speed commanded by a rotation drive source (not shown) (for example, a digital motor, etc.) under the control of the control device 18. [

The f? lens system (scanning lens, scanning optical system) FT is a telecentric scanning lens for projecting the beam LB1 reflected by the polygon mirror PM onto the reflection mirror M24. The beam LB1 transmitted through the f? lens system FT is projected onto the substrate P via the reflecting mirror M24 as spot light SP. At this time, the reflection mirror M24 reflects the beam LB1 toward the substrate P so that the beam LB1 advances toward the central axis AXo of the rotary drum DR with respect to the XZ plane. The incident angle? Of the beam LB1 to the f? Lens system FT changes according to the rotation angle? / 2 of the polygon mirror PM. The f? lens system FT projects the beam LB1 through the reflecting mirror M24 to an image height position on the surface to be irradiated of the substrate P proportional to the incident angle?. When the focal length is taken as fo and the image height position is taken as yo, the f? Lens system FT is designed to satisfy the relationship yo = fo x? (Distortion aberration). Therefore, it is possible to accurately scan the beam LB1 in the Y direction at the constant velocity by the f? Lens system FT. The plane (parallel to the XY plane) on which the beam LB1 incident on the f? Lens system FT is one-dimensionally deflected by the polygon mirror PM is a plane including the optical axis AXf of the f? .

3 is a diagram showing a specific configuration around the optical element for selection AOMn and the entrance mirror IMn. Since the structures around the selection optical element AOMn and the entrance mirror IMn are the same as each other, only the constitution around the selection optical element AOM1 and the entrance mirror IM1 will be described here.

As shown in Fig. 2, the optical element for selection AOM1 is passed through the selection optical element AOM4 and the reflection mirrors M9 and M10 at the front stage, and then, for example, A beam LB having a diameter (first diameter) parallel to the light beam (light flux) is incident. When the driving signal which is the high-frequency signal (ultrasonic signal) is not input (the driving signal is OFF), the selection optical element AOM1 transmits the incident beam LB as it is without diffracting. The transmitted beam LB passes through the condenser lens G1 and the collimator lens G2a provided along the optical axis AXa on the optical path and enters the optical element AOM2 for selection at the rear stage . It is assumed that the central axis of the beam LB passing through the optical element AOM1 for selection and passing through the condenser lens G1 and the collimator lens G2a passes on the optical axis AXa. The condensing lens G1 is a condensing lens that converts the beam LB (parallel light flux) transmitted through the selection optical element AOM1 to the position p1 of the surface p1 positioned between the condensing lens G1 and the collimator lens G2a To be a beam waist. The collimator lens G2a is condensed by the condensing lens G1, and then the divergent beam LB is made into a parallel beam. The diameter of the beam LB that is collimated by the collimator lens G2a becomes the first diameter. The rear focal point of the condensing lens G1 and the front focal point of the collimator lens G2a coincide within a predetermined allowable range and the front focal point of the condensing lens G1 is located at the diffraction point in the selective optical element AOM1 And coincide within a predetermined allowable range. The condenser lens G1 and the collimator lens G2a constitute a relay lens system.

On the other hand, in a period in which the drive signal as a high frequency signal is applied to the selection optical element AOM1, the selection optical element AOM1 generates a beam LB1 (diffracted light) in which the incident beam LB is diffracted . The beam LB1 (parallel beam) deflected in the -Z direction by the diffraction angle corresponding to the frequency of the high-frequency signal is transmitted through the condenser lens G1 and is incident on the incident mirror IM6 provided on the surface p1. The condensing lens G1 refracts the beam LB1 such that the central axis AXb of the beam LB1 deflected in the -Z direction is parallel to the optical axis AXa through which the beam LB passes, LB1 is converged (converged) so as to become a beam waist on or near the reflection surface of the incident mirror IM1. The beam LB1 is reflected in the -Z direction by the incidence mirror IM6 provided on the -Z direction side with respect to the optical path of the beam LB transmitted through the optical element for selection AOM1 to be incident on the collimator lens G2b, And enters the scanning unit U1. The collimator lens G2b converts the beam LB1 converged / diverged by the condenser lens G1 into a parallel light beam coaxial with the optical axis of the collimator lens G2b. The diameter of the beam LB1 that is collimated by the collimator lens G2b becomes the first diameter. The rear focal point of the condensing lens G1 and the front focal point of the collimator lens G2b coincide within a predetermined allowable range. The condenser lens G1 and the collimator lens G2b constitute a relay lens system. The condenser lens G1 and the collimator lenses G2a and G2b of FIG. 3 are arranged in the same optical path as the optical path of the other optical elements AOM2 to AOM6 shown in FIG. 2 do.

Since the optical axis of the f? Lens system FT is shown parallel to the XY plane in the scanning unit U1 shown in Fig. 2, the central axis of the beam LB1 projected from the scanning unit U1 to the substrate P The reflecting plane of the reflecting mirror M24 at the tip is inclined at an angle other than 45 degrees with respect to the XY plane so that the principal ray is directed to the central axis AXo of the rotary drum DR. However, when all of the scanning units U1 to U6 are inclined in the XZ plane so that the optical axis of the f? Lens system FT is inclined with respect to the XY plane, the optical axis of the f? It may be configured to be bent at 90 degrees.

4 is a view showing a specific configuration of the scanning unit U1 and is a plan view (XZ plane) perpendicular to the plane (plane parallel to the XY plane) including the scanning direction (deflection direction) of the beam LB1 FIG. 4, the optical axis AXf of the f? Lens system FT is arranged in parallel with the XY plane, and the reflecting mirror M24 at the tip is arranged so that the optical axis AXf is bent at 90 degrees. A beam splitter BE and a beam expander BE are disposed in the scanning unit U1 along the light transmission path of the beam LB1 from the incident position of the beam LB1 to the surface to be irradiated A reflecting mirror M21, a first cylindrical lens CY1, a spherical lens G10a, a reflecting mirror M22, a spherical lens G10b, and a spherical lens G10b. A reflection mirror M23, a polygon mirror PM, an f? Lens system FT, a reflection mirror M24, and a second cylindrical lens CY2.

The beam LB1 of the collimated light beam reflected by the incident mirror IM1 shown in Fig. 3 in the -Z direction is incident on the reflection mirror M20 inclined by 45 degrees with respect to the XY plane. The reflecting mirror M20 reflects the incident beam LB1 toward the reflecting mirror M21 in the -X direction away from the reflecting mirror M20 in the -X direction. The beam LB1 reflected by the reflecting mirror M20 passes through the beam expander BE and the aperture diaphragm PA and enters the reflecting mirror M21. The beam expander BE enlarges the diameter of the transmitted beam LB1. The beam expander BE has a condenser lens Be1 and a collimator lens Be2 that collimates the beam LB1 converged by the condenser lens Be1 and then diverges the beam LB1. It becomes easy to irradiate the beam LB6 onto the opening portion of the aperture diaphragm PA by the beam expander BE. Between the condensing lens Be1 and the collimator lens Be2, a tilt angle with respect to the beam LBn is changed by a driving motor or the like (not shown) in a quartz parallel plate HVP) are arranged as optical members for shifting. By changing the inclination angle of the parallel flat plate HVP, the imaging line SLn, which is the scanning locus of the spot light SP scanned on the substrate P, is moved in a small amount (for example, the spot light SP) To several tens of times the effective diameter &quot; of &quot;). This function will be described in detail later.

The reflecting mirror M21 is arranged inclined at 45 degrees with respect to the YZ plane and reflects the incident beam LB1 toward the reflecting mirror M22 away from the reflecting mirror M21 in the -Z direction in the -Z direction. The beam LB1 reflected by the reflecting mirror M21 in the -Z direction passes through the first cylindrical lens CY1 (first optical member) and the spherical lens G10a, and then passes through the reflecting mirror M22 It is. The reflecting mirror M22 is disposed at an angle of 45 degrees with respect to the XY plane, and reflects the incident beam LB1 toward the reflecting mirror M23 in the + X direction. The beam LB1 reflected by the reflection mirror M22 is incident on the reflection mirror M23 through the spherical lens G10b. The reflecting mirror M23 bends the incident beam LB1 in a plane parallel to the XY plane toward the polygon mirror (rotating polygon mirror, movable deflecting member) PM. One reflecting surface RP of the polygon mirror PM reflects the incident beam LB1 toward the f? Lens system FT having the optical axis AXf extending in the X-axis direction in the + X direction. The spherical lens G10a and the spherical lens G10b constitute a lens system (third optical member) G10. The spherical lenses G10a and G10b have an isotropic refractive power.

A first convex cylindrical lens CY1 made of a single lens is a lens having a refractive power in one direction and has an anisotropic refractive power. 5 is a view showing an example in which the optical path of the beam LB from the aperture diaphragm PA to the substrate P is developed on the XY plane and a plane parallel to the plane including the deflection direction of the beam LB FIG. As shown in Fig. 5, the first cylindrical lens CY1 is arranged in a plane perpendicular to the deflection direction of the beam LB1 by the polygon mirror PM (the rotation axis AXp of the polygon mirror PM) Direction), the incident beam LB1 is condensed (converged) in one dimension so as to become a beam waist on the surface p2 positioned immediately before the polygon mirror PM. The converging position (the position of the face p2) immediately before the polygon mirror PM is set as the first position. This first position is a position immediately before the lens system G10 (spherical lenses G10a and G10b). With respect to the direction (sub-scan direction) orthogonal to the deflection direction (main-scan direction) of the beam LB1 by the polygon mirror PM, the first cylindrical lens CY1 is arranged so that the incident beam LB1 (See Fig. 4). As described above, the first cylindrical lens CY1 is arranged so that the beam LB1 transmitted through the first cylindrical lens CY1 is directed in the direction (sub-scan direction) perpendicular to the deflection direction of the polygon mirror PM, (Sub-scanning direction) parallel to the X direction so as to be non-condensed with respect to the X-direction.

The lens system G10 (spherical lenses G10a and G10b) is arranged such that the deflection direction of the beam LB1 by the polygon mirror PM (the main scanning direction, the rotational direction) And the divergent beam LB1 is made to be a substantially parallel beam (refer to Fig. 5). The lens system G10 (spherical lenses G10a and G10b) is arranged such that the direction perpendicular to the deflection direction of the beam LB1 of the polygon mirror PM (sub-scan direction) (Converge) the beam LB1 of the collimated light flux transmitted through the light guide plate CY1 on the reflecting surface RP of the polygon mirror PM (see Fig. 4). Thereby, the beam LB1 projected onto the polygon mirror PM is converged on the reflecting surface RP into a slit shape (long oval shape) extending in the plane parallel to the XY plane. When the reflecting surface RP is inclined with respect to the Z direction by the first cylindrical lens CY1 and the lens system G10 and the second cylindrical lens CY2 described later The inclination of the reflecting surface RP with respect to the normal line) can be suppressed. For example, when the irradiation position of the beam LB1 (drawing line SL1) irradiated on the surface to be irradiated of the substrate P is slightly inclined with respect to each reflecting surface RP of the polygon mirror PM Tangent) in the X direction, that is, the surface tangent of each reflection surface RP can be corrected. The beam LB1 reflected by the reflecting surface RP is reflected by the fθ lens system FT in the direction of deflection (main scanning direction, rotational direction) of the beam LB1 by the polygon mirror PM, And enters the f? Lens system FT in a state of being diverged with a predetermined numerical aperture NA in the direction (sub-scanning direction) orthogonal to the deflection direction of the beam LB1 of the polygon mirror PM .

The rear focal point in accordance with the refractive power with respect to the deflection direction of the polygon mirror PM of the first cylindrical lens CY1 (the main scanning direction of the spotlight SP) and the front focal point of the lens system G10 are set to predetermined Are set to coincide with each other on the surface (p2) within the allowable range. The rear focal point of the lens system G10 and the front focal point of the f? Lens system FT are set to coincide with each other at a deflection position (on the reflecting surface RP) of the polygon mirror PM within a predetermined allowable range.

5, the f? lens system FT has a structure in which the beam LB1 of the polygon mirror PM is deflected by the beam of substantially parallel rays reflected by the reflecting surface RP, (Condensing) the light LB1 on the substrate P. [ Further, as shown in Fig. 4, in the f lens system FT, the direction (sub-scan direction) orthogonal to the deflection direction of the beam LB1 of the polygon mirror PM is a direction And the beam LB1 is projected toward the second cylindrical lens CY2 with almost parallel rays.

(Second optical member) CY2 which is a flat convex convex lens composed of a single lens has a bus line in a direction parallel to the Y direction (main scanning direction) and has power in one direction (sub scanning direction) The lens is an anisotropic lens. The second cylindrical lens CY2 transmits the incident beam LB1 as it is with respect to the deflection direction (main scanning direction, rotational direction) of the beam LB1 by the polygon mirror PM. Therefore, as shown in Fig. 5, the beam LB1 transmitted through the second cylindrical lens CY2 is directed to the deflecting direction (main scanning direction, rotational direction) of the beam LB1 by the polygon mirror PM Is condensed to be a beam waist on the substrate P by the refracting power of the f? Lens system FT. On the other hand, in the second cylindrical lens CY2, as to the direction (sub scanning direction) perpendicular to the deflection direction (main scanning direction) of the beam LB1 by the polygon mirror PM, Similarly, the incident beam LB1 of almost parallel rays is condensed (converged) on the substrate P to become beam waist. The beam LB1 projected onto the substrate P becomes the spot light SP of substantially circular shape on the substrate P (for example, the diameter is 3 m). As described above, the first and second cylindrical lenses CY1 and CY2 are arranged so that the busbars are orthogonal to each other so as to have power (refractive power) in directions orthogonal to each other. Thereby, the first cylindrical lens CY1 converges the beam LBn on the plane p2 immediately before the lens system G10 in one dimension with respect to the main scanning direction, The second cylindrical lens CY2 functions to converge the beam LBn behind the f? Lens system FT in the sub-scanning direction R. The second cylindrical lens CY2 functions to converge the beam LBn on the slope RP in one- In one dimension.

Since the first cylindrical lens CY1 and the second cylindrical lens CY2 are formed so as to be orthogonal to one another so that the busbars are orthogonal to each other, the polygon mirror PM is formed by the lens system G10, It is possible to satisfactorily correct spherical aberration of the beam LBn in both the deflection direction (main scanning direction) of the beam LBn caused by the light beam LBn and the sub-scanning direction orthogonal to the main scanning direction. Therefore, deterioration of imaging performance on the substrate P can be suppressed. By providing the first cylindrical lens CY1 and the second cylindrical lens CY2, a slight tilt error (surface tangle) for each reflection surface RP of the polygon mirror PM Suppression of shaking in the X direction (sub-scan direction) of the drawing line SLn, i.e., correction of the surface tangent, is performed in the same manner as in the conventional art.

The converging position (best focus position) of the spot light SP of the beam LBn projected on the substrate P is a predetermined converging position in the main scanning direction (deflection direction) and the sub scanning direction orthogonal to the main scanning direction It is assumed that the optical design is designed to coincide within the allowable range. The numerical aperture NA _y of the beam LBn (spot light SP) projected onto the substrate P in the main-scan direction and the numerical aperture NA _x in the sub-scan direction orthogonal to the main- It is assumed that they are designed to be the same within the allowable range. In the first embodiment, since the numerical aperture NA _{x is} approximately equal to the numerical aperture NA _y , the numerical aperture of the beam LBn projected onto the substrate P may be simply indicated by NA. The spherical aberration of the beam LBn is different from the spherical aberration of the beam LBn when the beam LBn is converged to the best focus plane of the design and the inclination angle (incident angle to the best focus plane) And the relative deviation of the focus direction of the position where each of the light beams condenses. The ray of the inclination angle? With respect to the central axis (main ray) perpendicular to the best focus plane of the beam LBn is represented by the numerical aperture NA? Calculated by sin?. The maximum numerical aperture NA of the beam LBn is approximately determined by the wavelength? Of the beam LBn, the effective diameter? Of the spot light SP, and the focal distance of the f? Lens system FT.

Next, the respective focal distances of the first cylindrical lens CY1, the second cylindrical lens CY2, the lens system G10 and the f? Lens system FT and the focal length of the aperture stop PA of the aperture stop PA, And a method for determining the magnification of the beam expander BE will be described. When the focal length of the first cylindrical lens CY1 is f _C1 , the focal distance of the second cylindrical lens CY2 is f _C2 , the focal length of the lens system G10 is f _G , the f lens system FT, Is represented by f _?. The diameter of the aperture stop of the aperture stop PA is represented by phi a.

The focal lengths f _C1 , f _C2 , f _G , and f? Have the following relationship (1). By determining the respective focal lengths of the first cylindrical lens CY1, the second cylindrical lens CY2, the lens system G10 and the f? Lens system FT based on the formula (1) The numerical aperture NA _x and the numerical aperture NA _y of the beam LBn projected onto the projection optical system P can be equalized.

^{_{f G 2 / f C1 = fθ}} 2 / f C2 ... (One)

The aperture stop diameter? A and the numerical aperture NA (= NA _x ? NA _y ) have a relationship expressed by the following equation (2).

? a = 2 占 NA (f? x f? _C1 / f? _G ) = 2 占 NA 占 f _G ? f? _C2 / f? (2)

A desired numerical aperture can be obtained by determining the aperture stop diameter? A based on this formula (2). The greater the magnification of the beam expander BE, the larger the amount of light not captured by the aperture stop PA increases, thereby increasing the amount of light loss. On the other hand, the smaller the magnification of the beam expander BE, the smaller the effective number of apertures on the image plane (on the substrate P) ) Is lowered. Therefore, it is desirable to set an enlargement magnification of the beam expander BE that is optimal in consideration of the balance between the light quantity and the resolution.

When each optical specification such as the first cylindrical lens CY1, the second cylindrical lens CY2, and the f? Lens system FT is roughly determined, the main scanning direction (deflection direction) of the beam LBn, which satisfy the single condition of the spherical aberration S ₁ and, - formula (3) shown in the spherical aberration S ₂ in the sub-scanning direction perpendicular to the main scanning direction of the beams (LBn), to at least 6, at, The optical specifications of the lens system G10 (spherical lenses G10a and 10b) are set. In the case where only the optical specifications of the f? Lens system FT are determined, the optical system of the lens system G10 (spherical lenses G10a and 10b) satisfies any one of the conditions (3) to (6) Specifications, optical specifications of the first cylindrical lens CY1 and the second cylindrical lens CY2 are set.

| S ₁ -S ₂ | <S _C1 × f? ² / f _G ² -S _C2 ... (3)

S ₁ <S _C1 × f? ² / f _G ² , and S ₂ <S _C2 ... (4)

| S ₁ -S ₂ | <? / NA _y ² , and | S ₁ -S ₂ | <? / NA _x ² ... (5)

S ₁ &lt; / NA _y ² , and S ₂ &lt; / NA _x ² ... (6)

| S ₁ -S ₂ | represents the absolute value of the difference between the spherical aberration S ₁ and the spherical aberration S ₂ , S _C1 represents the spherical aberration caused by the first cylindrical lens (CY1) alone , S _C2 represents the spherical aberration caused by the second cylindrical lens (CY2) unitarily, and λ represents the wavelength of the beam (LBn). The absolute value | S ₁ -S ₂ | of the difference between the spherical aberration S ₁ and the spherical aberration S ₂ is also the same as | S ₂ -S ₁ |. Although the scanning unit U1 has been described as an example, it goes without saying that the other scanning units U2 to U6 are likewise optically designed.

Here, when the extension directions of the busbars of the first and second cylindrical lenses CY1 and CY2 are set to be parallel to the main scanning direction (Y direction) together, The distances f _C1 , f _C2 , and f? Have the following relationship (7). In this case, the beam LBn projected onto the reflecting surface RP of the polygon mirror PM by the first cylindrical lens CY1, whose extending direction of the bus bar is parallel to the Y direction, (Long elliptic shape) extending in the direction parallel to the XY plane (main scanning direction) on the projection optical system RP. Thus, the lens system G10 becomes unnecessary.

f _C1 ? f _C2 = f? ² ... (7)

The diameter? A and the numerical aperture NA of the circular opening of the aperture diaphragm PA have the following relationship (8).

? a = 2 占 NA 占 f? = 2 占 NA 占 f _C1占_fC2 / f? (8)

[Example]

The face tangle correction according to the first embodiment is compared with the face tangle correction according to the conventional method. The numerical aperture NA and the specifications of the beam LBn incident on the scanning unit Un should be made equal to each other since it is necessary to compare them with each other as much as possible. This beam LBn is a non-polarized Gaussian beam whose intensity is 1 / e ² at a position 0.25 mm from the center of the optical axis (beam center line) and has a wavelength of 354.7 nm. The numerical aperture NA is a numerical aperture NA in the plane (XZ plane) including the numerical aperture NA _y standing in the plane (YZ plane) including the main scanning direction (deflection direction) and the direction (sub scanning direction) perpendicular to the main scanning direction The numerical aperture NA _{x is used} to divide it into NA _y = NA _x = 0.06. The same fθ lens system FT and second cylindrical lens CY2 are employed in the first embodiment and the conventional system. the focal length f? of the f? lens system FT is f? = 100 mm, and the focal distance f _C2 of the second convex cylindrical lens CY2 made of a single lens is f _C2 = 14.5 mm. In order to evaluate only the influence of the spherical aberration generated in the first cylindrical lens CY1 and the second cylindrical lens CY2, the f? Lens system FT has an ideal (ideal) and a lens having f-theta characteristics. First, a specific design example of the optical system for surface tangle correction of the scanning unit (Un) according to the conventional method is described in the first comparative example. Then, in the first embodiment, the optical system for surface tangle correction of the scanning unit (Un) Will be described. In the first embodiment and the conventional system, the members having the same configuration or the members having the same function are denoted by the same reference numerals. For the sake of simplicity, each of the reflection mirrors M21, M22, and M23 is omitted from the design example (lens data).

(Comparative Example 1)

In Comparative Example 1, the busbars of the first and second cylindrical lenses CY1 and CY2 are set together in the main scanning direction (Y direction), and the lens system G10 is not provided. The lens data according to the optical design example from the beam expander BE to the second cylindrical lens CY2 in Comparative Example 1 is shown in Fig. 7 is a graph showing the state of the beam LBn from the beam expander BE to the substrate (upper surface) P in Comparative Example 1 with respect to the deflection direction of the beam LBn (the scanning direction of the spotlight SP) In a plane parallel to the plane in which they are included. 8 shows the state of the beam LBn from the beam expander BE shown in Fig. 7 to the reflecting surface RP of the polygon mirror PM in a plane perpendicular to the deflection direction (main scanning direction) of the beam LBn (The surface including the sub-scanning direction). 9 shows the state of the beam LBn from the reflecting surface RP of the polygon mirror PM to the substrate (upper surface) P in the direction perpendicular to the deflection direction (main scanning direction) of the beam LBn Fig. In Fig. 6, after reflection of the polygon mirror PM, positive and negative signs of the surface interval and the radius of curvature are reversed. Figs. 7 to 9 are schematic views showing the optical members (the first cylindrical lens CY1 and the second cylindrical lens CY2, etc.) from the beam expander BE to the substrate P in Comparative Example 1, , And FIG. 6 is a view showing a state in which they are arranged at a scale according to the numerical example of FIG.

The beam LBn of the parallel beam incident on the scanning unit Un (effective beam diameter? Is 0.5 mm) is parallel to the beam expander BE formed of five spherical lenses LG1 to LG5 Converted into a luminous flux, and then shaped into a luminous flux of a circular cross section having a predetermined diameter in the aperture diaphragm PA. The aperture diaphragm diameter? A of the aperture diaphragm PA is set to 12 mm on the basis of the above equation (8). The enlargement magnification of the beam expander BE is set to be 24 so that the position where the intensity becomes 1 / e ² on the axis becomes 6 mm, which is the radius of the aperture stop diameter? A. At this time, the ratio of the amount of light loss by the aperture stop PA is about 13.5%.

The first convex cylindrical lens CY1 made of a single lens disposed behind the beam expander BE is orthogonal to the deflection direction of the beam LBn by the polygon mirror PM The incident beam LBn is condensed on the reflecting surface RP of the polygon mirror PM (see FIG. 8). The focal distance f _C1 of the first cylindrical lens CY1 is set to f _C1 = 693.1 mm on the basis of the above formula (7). The reflecting surface RP of the polygon mirror PM is located at the rear focal point of the first cylindrical lens CY1. With respect to the deflection direction (main-scan direction) of the beam LBn by the polygon mirror PM, the beam LBn transmitted through the first cylindrical lens CY1 remains parallel light (see Fig. 7) . Therefore, the beam LBn projected onto the polygon mirror PM converges on a slit shape (long elliptical shape) extending in the deflecting direction on the reflecting surface RP.

The beam LBn reflected by the reflection surface RP of the polygon mirror PM is incident on the f? Lens system FT having the focal distance f? Of 100 mm at an angle corresponding to the rotation angle of the polygon mirror PM. The reflecting surface RP of the polygon mirror PM is arranged so as to come to the position of the front focal point of the f? Lens system FT. Therefore, with respect to the deflection direction (main scanning direction) of the beam LBn by the polygon mirror PM, the beam LBn reflected by the reflecting surface RP of the polygon mirror PM is reflected by the f lens system FT, (See FIG. 7). On the other hand, the f? Lens system FT is configured to focus the beam LBn on the substrate P in a deflecting direction of the beam LBn by the polygon mirror PM Scanning direction orthogonal to the main scanning direction (main scanning direction), the beam LBn reflected by the reflecting surface RP of the polygon mirror PM is converted into parallel light (refer to FIG. 9).

The beam LBn transmitted through the f? lens system FT is incident on the polygon mirror PM by the second cylindrical lens CY2 having the focal length f _C2 of 14.5 mm disposed behind the f? lens system FT. Scanning direction of the beam LBn caused by the beam LBn is also focused on the surface to be irradiated (the upper surface) of the substrate P (see Fig. 9). The position of the second cylindrical lens CY2 is set such that the light converging position in the main scanning direction of the beam LBn by the polygon mirror PM and the light converging position in the sub- And the light converging position is set to be the surface to be irradiated (the upper surface) of the substrate P.

As described above, the beam LBn is irradiated onto the substrate P through the optical path of the first cylindrical lens CY1, the f? Lens system FT, and the second cylindrical lens CY2, The aberration in which the converging position of the beam LBn is largely different between the main scanning direction and the sub scanning direction is generated. This is due to the spherical aberration that occurs when the beam LBn converges as spot light. 10 and 11 are views for explaining the state of the spherical aberration of the beam LBn directed to the substrate P. Fig. 10 shows the state of the spherical aberration with respect to the main-scan direction of the beam LBn, Represents the state of the spherical aberration with respect to the sub-scan direction of the beam LBn.

As shown in Fig. 10, the beam LBn becomes a parallel beam of a certain thickness with respect to the main-scan direction and enters the f? Lens system FT and is focused mainly by the f? Lens system FT onto the principal ray (beam center line) Lpr) at a predetermined Z position (focus position). At that time, the second cylindrical lens CY2 acts as a simple parallel plate. The maximum number of openings on the main scanning direction of the beams (LBn), which emitted from the fθ lens system (FT) NA _y is, by the inclination angle (incident angle) βa to the principal ray (Lpr) of the light beam (LLa) faces the light-converging point, NA _y = sin [beta] a. The beam LBn includes a light ray LLb (incident angle b) having a smaller incident angle? A than the incident angle? A of the light ray LLa and a light ray LLc (incident angle? C) having an incident angle smaller than the incident angle? B of the light ray LLb do. Here, when the light-converging point by the light ray LLa of the incident angle beta is the focus position Zma in the Z-axis direction, the focus position Zmb of the light-converging point by the light ray LLb of the incident angle beta b, Are all shifted in the Z-axis direction with respect to the focus position Zma. Such deviation is spherical aberration.

11, the beam LBn enters the f? Lens system FT as a diverging light flux in the sub-scanning direction, is converted into a parallel light flux by the f? Lens system FT, (Focus position) on the principal ray (beam center line) Lpr in response to the refracting action of the second cylindrical lens CY2. The maximum numerical aperture NA _x of the beam LBn emitted from the second cylindrical lens CY2 in the sub scanning direction is set to coincide with the maximum numerical aperture NA _y in the main scanning direction. Therefore, the focus position Zsa at which the light beam LLa (incident angle? A) determined by NA _x = sin? A is condensed, the focus position Zsa at which the light beam LLb (incident angle b) smaller than the incident angle? Zsb and the focus position Zsc at which the light beam LLc (incident angle? C) having a smaller incident angle? B than the incident angle? B converges is shifted in the Z axis direction (focus direction) by the spherical aberration. 10 and 11 illustrate that spherical aberration is generated in the optical path from the f? Lens system FT to the substrate P, actual spherical aberration occurring in the beam LBn leading to the substrate P is (AOM, reflection mirror) through which the beam emitted from the light source device 14 of the light source unit 2 passes.

12 and 13 are graphs showing the relationship between the intensity of the simulated beam LBn and the maximum numerical aperture NA (= NA _y ? NA _x ) of the beam LBn is 0.06 based on the lens data of the comparative example 1 shown in Fig. And the abscissa represents the focus position (μm) in which the best focus position in design is zero point and the ordinate axis represents the maximum incidence angle βa (NAa) of the light ray LLa corresponding to the maximum numerical aperture NA of the beam LBn = sin? a) is normalized to 1.0 (? max). Therefore, in Figs. 12 and 13, for example, an incident angle? Of 0.5 means an angle of half of the maximum incident angle? A. 12 is the spherical aberration characteristic of the beam LBn projected onto the substrate P in relation to the main scanning direction and the characteristic B shown by the broken line indicates the spherical aberration characteristic of the beam LBn projected onto the substrate P. [ Scanning direction of the light beam LBn. 13 shows the spherical aberration characteristics by the difference [B- (A)] between the characteristic (A) and the characteristic (B) in Fig. 12, The best focus position is deviated in accordance with the incidence angle? Of the beam LBn projected on the projection optical system P, and spherical aberration of several tens of micrometers is generated.

12 is the spherical aberration generated by the beam expander BE and the f? Lens system FT, and the characteristic B in Fig. 12 is the spherical aberration generated by the beam expander BE, the first cylindrical lens CY1, the f? Lens system FT, and the second cylindrical lens CY2. The characteristic C that is the difference between the characteristic A and the characteristic B corresponds to the spherical aberration characteristic mainly generated by the first and second cylindrical lenses CY1 and CY2 .

(Example 1)

In the first embodiment, as described above, the extension direction of the bus bar of the first cylindrical lens CY1 is defined as the sub-scanning direction (X direction), and the extension direction of the bus bar of the second cylindrical lens CY2 is defined as (Y direction), and a lens system G10 is provided between the first cylindrical lens CY1 and the polygon mirror PM. Fig. 14 shows lens data for optical design from the beam expander BE to the second cylindrical lens CY2 in the first embodiment. 15 shows the state of the beam LBn from the beam expander BE to the substrate (upper surface) P in Embodiment 1 in the deflecting direction of the beam LBn (in the scanning direction of the spot light SP) In the plane parallel to the plane including the plane. 16 shows the state of the beam LBn from the beam expander BE shown in Fig. 15 to the reflecting surface RP of the polygon mirror PM in a plane orthogonal to the deflection direction (main scanning direction) of the beam LBn (In-plane including the sub-scanning direction). 17 is a plan view of the beam LBn from the reflecting surface RP of the polygon mirror PM to the substrate (upper surface) P shown in Fig. 15 in a plane perpendicular to the deflection direction (main scanning direction) of the beam LBn (In-plane including the sub-scanning direction). In Fig. 14, after reflection of the polygon mirror PM, the sign of the face interval and the radius of curvature is reversed. Figs. 15 to 17 are diagrams showing the optical members (the first cylindrical lens CY1 and the second cylindrical lens CY2, etc.) from the beam expander BE to the substrate P in Embodiment 1, And the actual scale according to the numerical example of Fig.

In the first embodiment, the distance (optical path length) from the first cylindrical lens CY1 to the top surface (surface to be processed of the substrate P) is shortened by about 300 mm as compared with the first comparative example, The focal length f _G of the lens system G10 is f _G = 201.2 mm and the focal length f _C1 of the first cylindrical lens CY1 is f _C1 = 58 mm. Thus, in Embodiment 1, compared with the design example of Comparative Example 1, an optical system that is a space saving can be realized. In addition, since the case of the scanning unit Un can be made smaller, the weight can be reduced.

The beam LBn (effective diameter 0.5 mm) of the collimated light beam incident on the scanning unit Un is enlarged in the beam expander BE composed of the four spherical lenses LGa to LGd, ) To a predetermined luminous flux diameter. The aperture diaphragm diameter? A of the aperture diaphragm PA is 3.5 mm based on the above formula (2). The enlargement magnification of the beam expander BE is increased by 7 times so that the intensity becomes 1 / e ² on the axis at a position of 1.75 mm, which is the radius of the aperture diaphragm diameter? A from the center, in the light flux after being magnified by the beam expander BE Setting. As described above, since the enlargement factor of the beam expander BE is smaller than that of the comparative example 1, the design of the beam expander BE is facilitated, and the spherical aberration generated in the beam expander BE can be reduced.

The first cylindrical lens CY1 having a focal length f _C1 of 58 mm and composed of a single lens disposed on the rear side of the beam expander BE has a deflection direction of the beam LBn by the polygon mirror PM The incident beam LBn is condensed on the rear focal plane p2 (first position) of the first cylindrical dichroic mirror CY1 (see Fig. 15). The position of this plane p2 is located between the first cylindrical lens CY1 and the lens system G10 arranged on the rear side of the first cylindrical lens CY1. With respect to the sub scanning direction orthogonal to the deflection direction (main scanning direction) of the beam LBn by the polygon mirror PM, the beam LBn transmitted through the first cylindrical lens CY1 remains parallel light (See Fig. 16).

A lens system G10 (focal length f _G = 201.2 mm) composed of two spherical lenses G10a and G10b is located at a position between the front focal point of the lens system G10 and the rear focal point of the first cylindrical lens CY1 (The surface p2) are arranged to coincide with each other within a predetermined allowable range. Therefore, the beam LBn transmitted through the lens system G10 is in the state of a parallel beam with respect to the main-scan direction of the beam LBn (see Fig. 15) Is condensed on the reflecting surface RP of the polygon mirror PM (see Fig. 16). The reflecting surface RP of the polygon mirror PM is set so as to come to the position of the rear focal point of the lens system G10. Therefore, the beam LBn projected onto the polygon mirror PM is converged on the reflecting surface RP in a slit shape (long oval shape) extending in the deflecting direction (main scanning direction).

The beam LBn reflected by the reflection surface RP of the polygon mirror PM is incident on the f? Lens system FT having the focal distance f? = 100 mm at an angle corresponding to the rotation angle of the polygon mirror PM. The f? lens system FT is arranged so that the reflecting surface RP of the polygon mirror PM is located at the front focal point of the f? lens system FT. Therefore, with respect to the deflection direction (main scanning direction) of the beam LBn by the polygon mirror PM, the beam LBn reflected by the reflecting surface RP of the polygon mirror PM is reflected by the f lens system FT, (Upper surface) of the substrate P in a telecentric state (a state in which the principal ray Lpr of the beam LBn is always parallel to the optical axis AXf of the f? Lens system FT) 15). On the other hand, with respect to the sub-scan direction orthogonal to the main-scan direction, the f? Lens system FT converts the beam LBn reflected by the reflecting surface RP of the polygon mirror PM into a diverging light flux into a parallel light flux See FIG. 17).

Finally, the beam LBn transmitted through the f? Lens system FT is reflected by a second cylindrical lens CY2 having a focal distance f _C2 = 14.5 mm disposed behind the f? Lens system FT, The sub-scanning direction orthogonal to the deflection direction (main scanning direction) of the beam LBn by the beam splitter PM is also condensed so as to become the spot light SP on the surface to be irradiated (the image surface) of the substrate P (see Fig. The position of the second cylindrical lens CY2 is set such that the light converging position in the main scanning direction of the beam LBn by the polygon mirror PM and the light converging position in the sub- And the light converging position is set to be the surface to be irradiated (the upper surface) of the substrate P. The beam expander BE, the aperture stop PA, the reflection mirror M21, the first cylindrical lens CY1, the reflection mirror M22 (see FIG. 4 and FIG. 5) ), The lens system G10 and the reflection mirror M23 is an optical system for converging the beam LBn projected onto the polygon mirror PM (movable deflecting member) with respect to the sub-scan direction orthogonal to the main- And functions as a first adjusting optical system including a first optical element having a refractive power or a first lens member (first cylindrical lens CY1). Further, in the configurations of Figs. 14 to 17 (and Figs. 4 and 5), the reflection mirror M24 and the second cylindrical lens CY2 behind the f? Lens system FT (main optical system) (Second cylindrical lens CY2) having an anisotropic refracting power for converging the beam LBn directed to the substrate P from the projection optical system FT with respect to the sub scanning direction And the second adjustment optical system.

18 and 19 show the spherical aberration characteristics of the simulated beam LBn with the maximum numerical aperture NAa of the beam LBn being 0.06 based on the lens data of the embodiment 1 shown in Fig. (Μm) in which the best focus position on the image plane is the zero point, and the vertical axis shows the normalized incident angle β as in FIGS. 12 and 13. 18 is the spherical aberration characteristic of the beam LBn projected onto the substrate P and the characteristic B shown by the broken line indicates the spherical aberration characteristic of the beam LBn projected onto the substrate P ) In the sub-scan direction. The characteristic (C) shown in Fig. 19 shows the spherical aberration characteristics by the difference [B (B) - (A)] between the characteristic (A) and the characteristic (B) in Fig. 18 is a spherical aberration generated by the composite system of the beam expander BE, the first cylindrical lens CY1, the lens system G10, and the f? Lens system FT, The characteristic B in the second lens group B is spherical aberration generated by the combination system of the beam expander BE, the lens system G10, the f? Lens system FT and the second cylindrical lens CY2. The characteristic C that is the difference between the characteristic A and the characteristic B corresponds to the spherical aberration characteristic mainly generated by the first and second cylindrical lenses CY1 and CY2 .

As a result of the simulation, in comparison with the characteristics (A) and (B) of the spherical aberration of Comparative Example 1 shown in Fig. 12, the absolute value of the aberration amount is reduced by about one digit in the case of the first embodiment. The spherical aberration generated in the first cylindrical lens CY1 is corrected by the lens system G10 as seen from the characteristic (A) in Fig. 18, The deviation of the best focus position is hardly caused by the angle of incidence β of the beam LBn projected on the projection optical system. This deviation, that is, the spherical aberration satisfies the above-mentioned conditions (4) and (6). Similarly, as can be seen from the characteristic (B) in Fig. 18, since the spherical aberration generated in the second cylindrical lens CY2 is corrected by the lens system G10, The deviation of the best focus position is hardly caused by the angle of incidence β of the beam LBn projected on the projection optical system. This deviation, that is, the spherical aberration satisfies the above-mentioned conditions (4) and (6). 19, the spherical aberration generated in the first cylindrical lens CY1 and the second cylindrical lens CY2 is corrected by the lens system G10 And the difference of the best focus position in accordance with the incident angle? Of the beam LBn projected onto the substrate P as the spot light SP is hardly generated. The difference in the best focus position, that is, the difference in spherical aberration satisfies the above-mentioned conditions (3) and (5). The reduction of the spherical aberration of the beam projected onto the substrate P in this manner is effective in reducing the minimum line width of the drawable pattern (high definition) SP in order to reduce the effective diameter of the beam LBn by 0.07 or more.

As described above, the scanning unit Un in the first embodiment is configured to project the beam LBn onto the substrate P while projecting the beam LBn from the light source device 14 onto the substrate P, A first cylindrical lens CY1 having power in one direction and a beam LBn transmitted through the first cylindrical lens CY1 are incident on the first cylindrical lens CY1 to be deflected for one- An f? Lens system FT for entering a beam LBn deflected by the polygon mirror PM and projecting the beam LBn in a telecentric state onto the substrate P, And a second cylindrical lens CY2 having a power in one direction and having a first cylindrical lens CY1 and a second cylindrical lens LY (Spherical aberration) are provided between the first cylindrical lens CY1 and the polygon mirror PM, and the first cylindrical lens CY1 and the polygon mirror PM are arranged so as to have power (refractive power) And a lens system G10 for correction is provided.

This makes it possible to correct the deviation of the projection position of the beam LBn caused by the plane tangles due to the respective reflection surfaces of the polygon mirror PM and to correct the deviation of the projection positions of the first cylindrical lens CY1, Spherical aberration caused by the dichroic lens CY2 can be corrected with a simple configuration. Therefore, deterioration of imaging performance of the spot light SP can be suppressed, and the resolution (fineness) of the pattern to be imaged on the substrate P can be increased. In addition, since the first since the focal length f _C2 of the cylindrical lens (CY1) The focal length f _C1 and the second cylindrical lens (CY2) of both it can be made smaller than the focal length of fθ of the fθ lens system (FT), The space saving optical system can be realized (see Figs. 7 to 9 and Figs. 15 to 17), and the size of the case of the scanning unit Un can also be reduced.

The first cylindrical lens CY1 condenses the incident beam LBn on the polarization direction just before the polygon mirror PM with respect to the deflection direction of the polygon mirror PM, The beam LBn after being converged by the first cylindrical lens CY1 is diverged into parallel light and the incident beam LBn is incident on the polygon mirror LBn with respect to the sub scanning direction orthogonal to the deflecting direction PM) on the reflecting surface RP of the photodetector. This makes it possible to converge the beam LBn projected onto the polygon mirror PM into a slit shape (long elliptic shape) extending in the deflecting direction on the reflecting surface RP. The f lens system FT converges the incident beam LBn on the substrate P with respect to the deflection direction and reflects the light beam LBn on the reflecting surface RP And the second cylindrical lens CY2 is arranged so that the incident beam LBn is projected on the substrate P with respect to the direction orthogonal to the deflection direction Concentrate. As a result, even when the reflecting surface RP is tilted with respect to the Z direction (inclination of the reflecting surface RP with respect to the normal to the XY plane), the reflecting surface RP and the substrate P are arranged with respect to the sub- It is possible to prevent the projection position of the beam LBn from deviating in the sub-scanning direction for each reflection surface RP.

(Modified Example 1)

According to the first embodiment, as shown in Embodiment 1 (Fig. 14), each of the first and second cylindrical lenses CY1 and CY2 has a surface on the side where the beam is incident, And is formed of a cylindrical surface having a constant radius of curvature with respect to the scanning direction, and the surface on the side of beam emission is formed in a plane. However, the respective cylindrical surfaces of the first and second cylindrical lenses CY1 and CY2 may be curved surfaces having a plurality of curved surfaces having slightly different curvature diameters smoothly connected to each other Aspheric surface). The planar side of each of the first and second cylindrical lenses CY1 and CY2 may be formed in a cylindrical shape having a predetermined curvature radius (a finite value other than infinite) in the main scanning direction or the sub- It may be processed into a face shape. The wavelength? Of the beam LBn (the emission beam of the light source device 14) incident on each of the scanning units Un is not limited to the wavelength 354.7 nm of the ultraviolet region set in Example 1 or Comparative Example 1 , Or other wavelengths (visible light, infrared light). When chromatic aberration is eliminated in the lens system G10, a plurality of beams having different wavelengths are incident on the polygon mirror PM coaxially (or in parallel), and the plurality of spotlights SP having different wavelengths are incident on the substrate P, Can be scanned. Alternatively, the beam LBn may be a wide wavelength band light whose intensity is distributed within a constant wavelength width with respect to the center wavelength by the chromatic aberration of the lens system G10. The beam LBn may have polarization components instead of non-polarized light, and the intensity distribution in the cross section of the beam may be a uniform intensity distribution (almost rectangular or trapezoidal distribution) rather than a Gaussian distribution.

(Modified example 2)

In the first embodiment, the beam LBn is deflected using the polygon mirror PM, but the beam LBn may be deflected using a pivotable galvanometer mirror (movable deflecting member, pivotal reflecting mirror). In this case as well, the beam LBn reflected from the galvanometer mirror is projected onto the substrate P (irradiated surface) through the f? Lens system FT. Therefore, when correction by the surface tangent of the reflecting surface of the galvanometer mirror is required , The first cylindrical lens CY1 and the lens system G10 may be provided before the galvanometer mirror and the second cylindrical lens CY2 may be provided after the f lens system FT. The lens system G10 is composed of two spherical lenses G10a and G10b, but it may be a single lens or three or more lenses. The spherical lenses G10a and G10b constituting the lens system G10 may be made of an aspheric lens. Furthermore, although a cylindrical lens is used as the first optical member CY1 and the second optical member CY2, it is sufficient that the lens has a relatively large refractive power in one direction and refractive power in a direction orthogonal to the direction. For example, a toric lens or an anamorphic lens may be used as the first optical member CY1 and the second optical member CY2.

(Modification 3)

According to the first embodiment, each of the first and second cylindrical lenses CY1 and CY2 is composed of a single lens. As a result, the fabrication and assembly (adjustment) of the first and second cylindrical lenses CY1 and CY2 can be simplified, and the cost can be reduced. However, in order to correct spherical aberration of the beam LBn, it is also possible to constitute the second cylindrical lens CY2 particularly by a plurality of lenses. When the second cylindrical lens CY2 is composed of a plurality of lenses (for example, two lenses), it is necessary to perform an adjustment operation for accurately aligning the rotational orientations of the busbars between the plurality of lenses . When the second cylindrical lens CY2 is constituted by a plurality of lenses (for example, two lenses), the direction in which the busbars of the first cylindrical lens CY1 extend extends as in Comparative Example 1 The spherical aberration of the beam LBn projected on the substrate P can be corrected well even if the lens system G10 is omitted in parallel with the main scanning direction. In this case, as shown in Comparative Example 1, it is necessary to make the focal distance f _C1 of the first cylindrical lens CY1 longer than the focal length f? Of the f? Lens system FT, ) Becomes longer. However, even if the focal length f _C2 of the second cylindrical lens CY2 is set small relative to the focal length f? Of the f? Lens system FT, the spherical aberration can be suppressed to be small.

14 or 17), a beam scanning device (or a writing device) for scanning the spot light SP of the beam LBn in one dimension from the substrate P (object to be irradiated) ) For projecting a beam LBn converged with respect to the sub-scanning direction onto a reflecting surface RP of a polygon mirror PM (beam deflecting member) for deflecting the beam LBn, A lens CY1 for projecting the beam LBn deflected by the polygon mirror PM toward the substrate P and for scanning the substrate P in one dimension, A single lens or a plurality of plural lenses arranged in the sub-scanning direction, which are arranged between the substrate P and the f? Lens system FT, for converging the beam LBn projected from the f? Lens system F, (F?) Of the f? Lens system FT and the focal length f _C2 of the second cylindrical lens CY2 are provided on the second cylindrical lens CY2 (second optical member) relation (Or drawing apparatus) in which the spherical aberration of the beam LBn projected along the predetermined numerical aperture is reduced on the substrate P is obtained by setting f?> F _C2 .

[Second Embodiment]

4, in the optical path between the lens systems Be1 and Be2 constituting the beam expander BE in the scanning unit Un, the imaging line SLn is moved in the sub-scanning direction (X direction) In order to perform microscopic shift, a slantable parallel plate (HVP) as an optical member for soft is provided. 20A and 20B illustrate how the drawing line SLn is shifted by the inclination of the parallel flat plate HVP. FIG. 20A shows a state in which the parallel and parallel planes of the parallel flat plate HVP, (Principal ray) of the parallel plate LBn, that is, the parallel plate HVP is not inclined in the XZ plane. 20B shows the case where the parallel planes HVP and the parallel planes HVP are inclined at 90 degrees with respect to the center line (main ray) of the beam LBn, that is, when the parallel plate HVP is inclined at an angle? As shown in Fig.

20A and 20B, the optical axis AXe of the lens system Be1 and Be2 is parallel to the optical axis AXe of the circular aperture of the aperture stop PA when the parallel plate HVP is not inclined (angle? = 0 degrees) And the center line of the beam LBn incident on the beam expander BE is adjusted to be coaxial with the optical axis AXe. The position of the rear focal point of the lens system Be2 is arranged so as to coincide with the position of the circular opening of the aperture diaphragm PA. The position of the aperture diaphragm PA is determined by the first cylindrical lens CY1 and the lens system G10 (spherical lenses G10a and 10b) shown in FIG. 16, (Or the position of the front focal point of the f? Lens system FT) of the reflecting surface RP of the projection optical system PM. On the other hand, with respect to the main scanning direction, the aperture diaphragm PA is arranged so as to be optically conjugate with the position of the incident pupil, which is the position of the front focal point of the f? Lens system FT. Therefore, when the parallel flat plate HVP is inclined by the angle?, The center line of the beam LBn (here, the diverging light flux) transmitted through the parallel plate HVP and incident on the lens system Be2, -Z direction and the beam LBn emitted from the lens system Be2 is converted into a parallel beam and the centerline of the beam LBn is slightly inclined with respect to the optical axis AXe.

The beam LBn (parallel light beam) emitted obliquely from the lens system Be2 passes through the aperture diaphragm PA since the position of the rear focal point of the lens system Be2 is arranged to coincide with the position of the circular aperture of the aperture stop PA. And is projected on the circular opening and continues. Thus, the aperture beams (LBn) which has passed through the circular aperture of the diaphragm (PA) is the strength of the base of the intensity distribution on the 1 / e ² in exactly keothan state, a bit in the scan direction unit from the XZ-plane about the optical axis (AXe) And is directed to the first cylindrical lens CY1 at the rear end at an inclined angle. The aperture diaphragm PA corresponds to the pupil position when viewed from the reflecting surface RP of the polygon mirror PM with respect to the sub scanning direction and is a portion of the beam LBn passing through the circular aperture of the aperture diaphragm PA. The position on the reflecting surface of the beam LBn (converging with respect to the sub-scanning direction) incident on the reflecting surface RP of the polygon mirror PM is slightly shifted in accordance with the inclination angle with respect to the scanning direction. Therefore, the beam LBn reflected by the reflecting surface RP of the polygon mirror PM is also slightly inclined in the Z direction with respect to the plane parallel to the XY plane including the optical axis AXf of the f? Lens system FT shown in Fig. 4 And enters the f? Lens system FT. As a result, in the case of the optical path shown in FIG. 17, the beam LBn incident on the second cylindrical lens CY2 is slightly inclined in the sub-scanning direction, and the beam LBn projected onto the substrate P, The position of the spot light SP in the sub scanning direction is slightly shifted. In FIGS. 4 and 20, both of the lens systems Be1 and Be2 constituting the beam expander BE are spherical lenses (convex lenses) having a positive refractive power. However, the beams LBn may be incident on the incidence side May be a spherical lens (concave lens) having a negative refractive power. In this case, the beam LBn emitted from the lens system Be1 becomes a diverging light flux without converging, enters the lens system Be2, and is converted into a parallel light beam whose beam diameter is enlarged by the lens system Be2.

The bus bar of the first cylindrical lens CY1 and the bus bar of the second cylindrical lens CY2 are arranged in parallel to each other and the second cylindrical lens CY2 is arranged in a single lens As shown in Figs. 12 and 13, a large spherical aberration remains. Therefore, when the parallel flat plate HVP is provided in the beam expander BE (Figs. 7 and 8) of Comparative Example 1 and inclined, the position of the beam LBn incident on the second cylindrical lens CY2 A larger spherical aberration is generated due to a slight change in the tilt in the sub-scanning direction. On the other hand, as in the first embodiment, the bus bar of the first cylindrical lens CY1 and the bus bar of the second cylindrical lens CY2 are arranged in a mutually orthogonal relationship, and the lens system G10 is provided , Or when the second cylindrical lens CY2 is constituted by a plurality of lenses as described in Modification 3, the spherical aberration of the spherical aberration can be corrected by using the effective Can be satisfactorily corrected to a size (diameter)? Or less. Therefore, when the position of the beam LBn incident on the second cylindrical lens CY2 is slightly changed in the sub scanning direction when the parallel flat plate HVP is tilted, the increment of the spherical aberration Increase.

Since the parallel flat plate HVP shown in Fig. 4 (Fig. 20) is provided in each of the scanning units Un, by continuously changing the inclination angle eta of the parallel flat plate HVP for each scanning unit Un, P can be expanded and contracted at a minute rate in the sub-scan direction. Therefore, even when the substrate P is partially expanded and contracted with respect to the longitudinal direction (sub-scanning direction) of the substrate P, the second pattern is formed on the base pattern (first layer pattern) It is possible to maintain the overlapping accuracy at the time of overlapping exposure (drawing) of the layer pattern. Locally expanding and contracting the substrate P in the longitudinal direction (sub scanning direction) can be performed by aligning alignment marks formed at constant pitches (for example, 10 mm) in the longitudinal direction on both sides in the width direction of the substrate P, It can be predicted immediately before each of the scanning units Un draws a pattern by enlarging them with a microscope and imaging them sequentially with the image pickup device and analyzing the change in the longitudinal direction of the mark position (the pitch change of the mark, etc.). An example of the arrangement of the alignment marks, the arrangement of the alignment microscope, and the like is disclosed in, for example, International Publication No. 2015/152218.

Claims (40)

1. A beam scanning device for scanning a beam from a light source device onto a workpiece while projecting the beam on the workpiece in one dimension,
A first optical member for condensing the beam in a first direction corresponding to the one-dimensional direction,
A beam deflecting member for deflecting the beam in the first direction for the one-dimensional scanning,
A main optical system for entering the beam deflected by the beam deflecting member and projecting the beam toward the object to be irradiated,
A second optical member that receives the beam passing through the main optical system and condenses the beam in a second direction orthogonal to the first direction,
And a lens system which is provided between the first optical member and the beam deflecting member and condenses the beam passed through the first optical member in the second direction at the position of the beam deflecting member. The method according to claim 1,
Wherein the first direction is a main scanning direction for scanning the beam by the beam deflecting member in one dimension and the second direction is a sub scanning direction orthogonal to the main scanning direction. The method of claim 2,
Wherein the beam deflection member is a rotating polyhedral mirror that deflects the beam repeatedly in the main scanning direction by rotating a plurality of reflection surfaces continuously. The method of claim 3,
Wherein the first optical member focuses the beam in the main scanning direction at a position immediately before the beam is incident on the lens system,
And the second optical member condenses the beam with respect to the sub scanning direction at the position of the object to be irradiated. The method of claim 4,
Wherein said lens system is arranged such that said beam converged in said main scanning direction by said first optical member is incident on said beam to be diverged so as to be substantially parallel light in said main scanning direction and in said sub scanning direction, And converging the light on the reflecting surface. The method according to any one of claims 1 to 5,
Each of said first optical member, said lens system, said beam deflecting member, and said injection optical system,
The position of the rear focal point of the first optical member and the position of the front focal point of the lens system coincide within a predetermined allowable range,
Wherein a position of a back focal point of the lens system and a position of a front focal point of the main optical system are disposed so as to be located in the beam deflecting member within a predetermined allowable range. The method according to any one of claims 1 to 6,
Wherein the numerical aperture in the first direction of the beam projected onto the irradiated object and the numerical aperture in the second direction are set to the same within a predetermined allowable range. The method of claim 7,
When the focal length of the first optical member is f _C1 , the focal distance of the second optical member is f _C2 , the focal length of the lens system is f _G , and the focal distance of the injection optical system is fθ,
^{_{f G 2 / f C1 = fθ}} 2 / f C2
Of the beam scanning device. The method according to claim 7 or 8,
Further comprising an aperture diaphragm for shaping the beam incident on the first optical member into a light flux (light beam) of a circular cross section having a predetermined diameter. The method of claim 9,
The numerical aperture NA of the beam projected onto the object to be irradiated and the diameter?
φa = 2 × NA (fθ × f C1 / f G) = 2 × NA × (f G × f C2 / fθ)
Of the beam scanning device.
(Where, _C1 f: focal length of the scanning optical system of the first focal length of the optical member, _C2 f: focal length of the second optical member, f _G:: the focal length of the lens system, fθ) The method according to any one of claims 1 to 10,
Wherein the beam incident on the first optical member is a beam expanded by a beam expander. The method according to any one of claims 1 to 11,
Wherein the first optical member and the second optical member are single lenses,
Wherein the lens system is composed of a plurality of lenses. The method according to any one of claims 1 to 12,
Wherein the main scanning optical system is an f? Lens system having a proportional relationship between a change in the deflection angle of the beam in the main scanning direction and a change in projection position on the irradiated object,
Wherein the lens system comprises at least one spherical lens or aspherical lens. The method according to any one of claims 1 to 13,
Wherein the first optical member and the second optical member are cylindrical lenses provided so that the extension directions of the bus bars are orthogonal to each other. 15. The method of claim 14,
The spherical aberration in the first direction in the first optical member alone is S _C1 and the spherical aberration in the second direction in the second optical member is S _C2 , S ₁ of the spherical aberration in the first direction of the beam incident to the adjustable member and the spherical aberration is a difference between S ₂ in the second direction _{(差分) | S 1 -S 2} | a,
| S ₁ -S ₂ | <S _C1 × f? ² / f _G ² -S _C2
Is satisfied. &Lt; / RTI &gt;
(Where f _G is a focal length of the lens system, and f &amp;thetas; is a focal length of the injection optical system) The method according to claim 14 or 15,
Wherein the spherical aberration S ₁ of the beam projected on the object to be projected in the first direction and the spherical aberration S ₂ of the beam in the second direction,
S ₁ <S _C1 × f? ² / f _G ² , and S ₂ <S _C2
Is satisfied. &Lt; / RTI &gt;
(Where f _G is the focal length of the lens system, f 慮 is a focal length of the primary optical system, S _C1 is a spherical aberration in the first direction occurring in the first optical member, S _C2 is a refractive index of the second optical member, Spherical aberration in the second direction occurring in the group) The method according to any one of claims 14 to 16,
S ₁ and the spherical aberration for the first direction of the beam incident to the irradiated body, the difference between the spherical aberration S ₂ (差分) relating to the second direction | S ₁ -S ₂ | a,
| S ₁ -S ₂ | <? / NA _y ² , and | S ₁ -S ₂ | <? / NA _x ²
Is satisfied. &Lt; / RTI &gt;
(Where, λ: wavelength of the beam, _y NA: the numerical aperture for the first direction of the beam, _x NA: numerical aperture on the second direction of the beam) The method according to any one of claims 14 to 17,
S ₁ and the spherical aberration for the first direction of the beam incident to the irradiated body, the spherical aberration S ₂ relating to the second direction,
S ₁ &lt; / NA _y ² , and S ₂ &lt; / NA _x ²
Is satisfied. &Lt; / RTI &gt;
(Where, λ: wavelength of the beam, _y NA: the numerical aperture for the first direction of the beam, _x NA: numerical aperture on the second direction of the beam) A drawing apparatus for drawing a pattern on a workpiece while relatively moving a workpiece and a beam in a subscanning direction while scanning a beam from a light source device on a workpiece in a main scanning direction,
A movable deflecting member for deflecting the beam in the main scanning direction in one dimension to scan the beam in the main scanning direction;
A scanning optical system for scanning the projection optical system with respect to the projection optical system, a scanning optical system for projecting the beam deflected one-dimensionally from the movable deflecting member,
A first optical member having an asymmetric refractive power and converging the beam toward the movable deflecting member with respect to the main scanning direction;
A second optical member having an anisotropic refracting power and converging with respect to the sub scanning direction, the beam projected from the injection optical system and directed to the irradiated object;
Scanning direction, and a beam converging with respect to the main scanning direction is converted into a beam converging with respect to the sub-scanning direction, and is emitted toward the movable deflecting member And a third optical member having an isotropic refracting power. The method of claim 19,
The first optical member condenses the beam toward the movable deflecting member so as to be a beam waist with respect to the main scanning direction at a first position between the first optical member and the movable deflecting member, And sets the non-converging state for the sub-scanning direction. The method of claim 20,
The third optical member condenses the beam from the first optical member to be a beam waist at the deflecting position of the movable deflecting member in the sub scanning direction and makes the beam converge to the main scanning direction Drawing device. 23. The method of claim 21,
The position of the rear focal point in accordance with the refractive power of the first optical member with respect to the main scanning direction and the position of the front focal point of the third optical member coincide with the first position within a predetermined allowable range,
The position of the rear focal point of the third optical member and the position of the front focal point of the main optical system coincide with the deflecting position of the movable deflecting member within a predetermined allowable range. The method as claimed in any one of claims 19 to 22,
Wherein the numerical aperture in the main scanning direction of the beam projected onto the object matches the numerical aperture in the sub scanning direction within a predetermined allowable range. 24. The method of claim 23,
A focal length of the first optical member according to a refractive power in the main scanning direction is f _C1 , a focal distance of the second optical member according to a refractive power in the sub-scanning direction is f _C2 , f _G , and the focal distance of said main optical system is f?
^{_{f G 2 / f C1 = fθ}} 2 / f C2
Is set to satisfy a relationship within a predetermined error range. 27. The method of claim 24,
Further comprising an aperture diaphragm for shaping the beam incident on the first optical member into a beam having a circular cross section with a predetermined diameter. 26. The method of claim 25,
Wherein the numerical aperture NA of the beam projected on the object and the diameter phi a of the beam,
φa = 2 × NA (fθ × f C1 / f G) = 2 × NA × (f G × f C2 / fθ)
Is set to satisfy a relationship within a predetermined error range. 26. The apparatus according to any one of claims 19 to 26,
Wherein the first optical member and the second optical member are composed of a single lens having an anisotropic refracting power, and the third optical member is composed of a plurality of lenses having an isotropic refracting power. 28. The method according to any one of claims 19 to 27,
The first optical member and the second optical member may include a cylindrical lens, a toric lens, and an anamorphic lens having different refractive powers in directions orthogonal to each other in a plane perpendicular to the optical path on which the beam travels, lens,
Wherein the third optical member includes a spherical lens or an aspherical lens having an isotropic refractive power in a plane perpendicular to an optical path along which the beam travels. 28. The method according to any one of claims 19 to 28,
Wherein the movable deflecting member is a rotating polygonal mirror or a swinging mirror having a reflecting surface for reflecting the beam and the angle of the reflecting surface changing with respect to the main scanning direction,
Wherein the scanning optical system is an f? Lens system in which a deflection angle of the beam deflected by the movable deflecting member is proportional to a position of an image height of the beam projected on the object. 1. A drawing apparatus for drawing a pattern onto a workpiece by scanning a beam deflected in a first direction on a movable deflecting member in a first direction on the workpiece while projecting the beam onto a workpiece by a scanning optical system,
And a first lens element having an asymmetric refractive power for converging the beam projected onto the movable deflecting member with respect to a second direction perpendicular to the first direction,
And a second adjusting optical system including a second lens member having an anisotropic refracting power for converging the beam from the injection optical system toward the irradiated object in the second direction,
The wavelength of the beam is λ, the numerical aperture of the beam projected on the object to be projected in the first direction is NA _y , the numerical aperture of the beam in the second direction is NA _x , When the spherical aberration in the first direction is S ₁ and the spherical aberration in the second direction is S ₂ , the first lens member and the second lens member,
S ₁ &lt; lambda / NA _y ² and the condition that S ₂ &lt; lambda / NA _x ² ,
| S ₁ -S ₂ | <λ / NA _y ² , and the condition that | S ₁ -S ₂ | <λ / NA _x ² is satisfied. 32. The method of claim 30,
Wherein the first adjusting optical system includes a third lens member having an isotropic refractive power for causing the beam passing through the first lens member to enter and project toward the movable deflecting member,
Wherein the first lens member is arranged to converge the beam with respect to the first direction between the first lens member and the third lens member. 32. The method of claim 31,
Further comprising a light source device for generating the beam,
Wherein the first adjustment optical system further comprises a beam expander system for enlarging a diameter of the beam emitted from the light source device. 33. The method of claim 32,
The spherical aberration S ₁ relating to the first direction is generated by the beam expander system, the first lens member, the third lens member, and the main optical system,
And the spherical aberration S ₂ relating to the second direction is generated by the beam expander system, the third lens member, the main optical system, and the second lens member. A patterning device for scanning the patterning beam in one direction along the main scanning direction on the object to be reproduced and moving the object to be irradiated and the beam in a sub scanning direction crossing the main scanning direction to draw a pattern on the object to be irradiated, as,
A beam generating device for generating the beam;
A beam expander for converting the beam from the beam generating device into a parallel beam having an enlarged beam diameter;
A beam deflecting member for deflecting the beam converted by the beam expander in one direction in a direction corresponding to the main scanning direction,
A main optical system for focusing the spot of the beam on the object to be irradiated with the one-dimensional deflected beam,
For converging the beam projected on the beam deflecting member in a direction corresponding to the sub-scanning direction, the beam expander being provided between the beam expander and the beam deflecting member, A first optical system including a first optical element having an anisotropic refractive power,
A second optical system including a second optical element having an anisotropic refracting power for converging the beam projected from the scanning optical system and directed to the irradiated object in the sub scanning direction,
And a shifting optical member which is provided in an optical path of the beam expander and shifts the optical path of the beam in a direction corresponding to the sub-scanning direction. 35. The method of claim 34,
Wherein the beam expander includes a first lens system for making the beam incident from the beam generating apparatus and a second lens system for converting the beam passing through the first lens system into a parallel beam,
Wherein the shift optical member is a parallel flat plate disposed between the first lens system and the second lens system at an inclination angle variable. 36. The method of claim 35,
Further comprising an aperture stop which is disposed at a rear focal point of the second lens system of the beam expander and cuts the intensity of the bottom side of the intensity distribution of the beam magnified by the beam expander. 37. The method of claim 36,
Wherein the beam deflecting member has a reflecting surface that reflects the beam from the beam expander toward the main optical system and changes its angle in a direction corresponding to the main scanning direction,
Wherein the reflecting surface of the beam deflecting member is arranged so as to be optically conjugate with the irradiated object by the injection optical system and the second optical system with respect to the direction corresponding to the sub scanning direction, And the direction corresponding to the main scanning direction is disposed at a position of the front focal point of the main optical system. 37. The method of claim 37,
The position of the aperture stop is set to the position of the pupil of the first optical system with respect to the direction corresponding to the sub scanning direction when viewed from the reflecting surface of the beam deflecting member and to the direction corresponding to the main scanning direction Is set to be optically conjugate with the position of the reflecting surface of the beam deflecting member or the position of the front focal point of the main optical system by the first optical system. 42. The method of claim 38,
The first optical element of the first optical system has a refractive power only in a direction corresponding to the main scanning direction and is a first cylindrical lens that makes incident the beam passing through the aperture stop,
And said second optical element of said second optical system is a second cylindrical lens having a refractive power only in a direction corresponding to said sub-scanning direction. 42. The method of claim 39,
Wherein the first optical system includes a spherical or aspherical lens having an isotropic refracting power which is incident on the beam passing through the first cylindrical lens and is emitted toward the reflecting surface of the beam deflecting member.

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