CN113552778B

CN113552778B - Pattern drawing apparatus and pattern drawing method

Info

Publication number: CN113552778B
Application number: CN202110922904.XA
Authority: CN
Inventors: 加藤正纪; 中山修一
Original assignee: Nikon Corp
Current assignee: Nikon Corp
Priority date: 2016-10-04
Filing date: 2017-05-15
Publication date: 2023-10-20
Anticipated expiration: 2037-05-15
Also published as: KR20190055243A; TWI736621B; CN109791371B; JPWO2018066159A1; CN109791371A; TW201826035A; WO2018066159A1; CN113552778A; JP6919660B2; KR102414046B1

Abstract

The pattern drawing device (EX) of the present invention comprises: a position Measurement Unit (MU) for measuring the position of the exposed region on the substrate (P) to be drawn by the plurality of drawing units (Un); a 1 st adjustment means (HVP) for adjusting the position of each light Spot (SP) based on the drawing means (Un) in the 2 nd direction during the movement of the substrate (P) based on the position measured by the position Measuring Unit (MU) in order to reduce the position error of each drawn pattern by the drawing means (Un) with respect to the exposure region; and a 2 nd adjustment member (AOM 1) for adjusting the position of each light Spot (SP) based on the drawing unit (Un) in the 2 nd direction with a response higher than that of the 1 st adjustment member (HVP) during the movement of the substrate (P) in order to reduce the bonding error of each drawn pattern by the drawing unit (Un) in the 2 nd direction.

Description

Pattern drawing apparatus and pattern drawing method

The invention is a divisional application of an invention patent with the application date of 2017, 05, 15, the application number of 201780061213.7 and the name of pattern description device and pattern drawing method.

Technical Field

The present invention relates to a pattern drawing apparatus and a pattern drawing method for drawing a pattern by scanning a light spot irradiated onto an irradiation subject.

Background

As a drawing device using a rotary polygon mirror, for example, there is known an image forming device including a plurality of laser exposure sections each having a polygon mirror, wherein a part (end) of a scanning area in a main scanning direction in which an exposure beam is scanned by the polygon mirror is overlapped, and an image is drawn by sharing the exposure beam from the plurality of laser exposure sections, as disclosed in japanese patent application laid-open No. 2008-200964. In the apparatus of japanese patent application laid-open No. 2008-200964, in order to reduce the case where the exposure light beam is shifted in the sub-scanning direction orthogonal to the main scanning direction due to the difference in the surface inclination of the plurality of reflection surfaces of the polygon mirror in the region overlapping at the end of the scanning region, when the rotations of the polygon mirrors of the plurality of laser exposure sections are synchronized, the combination of the reflection surfaces (the angular phase in the rotation direction) of the 2 polygon mirrors is adjusted so that the shift in the sub-scanning direction of the image drawn by 1 polygon mirror and the overlapping region image of the image drawn by the other polygon mirror becomes smaller. Japanese patent application laid-open No. 2008-200964 also discloses a mechanism for mechanically moving a laser exposure section including a polygon mirror in a sub-scanning direction, and adjusting the laser exposure section so as to reduce the shift of the overlapping region of the images.

Disclosure of Invention

A 1 st aspect of the present invention is a pattern drawing apparatus in which a plurality of drawing units for drawing a pattern by scanning a drawing beam focused on a substrate in a form of a light spot in a 1 st direction are arranged in the 1 st direction, and the pattern drawn by the plurality of drawing units is drawn by bonding the pattern in the 1 st direction by a movement of the substrate in a 2 nd direction intersecting the 1 st direction, the apparatus comprising: a position measuring unit for measuring a position of an exposure target area on the substrate to be drawn by the drawing units; a 1 st adjustment means for adjusting the position of the light spot based on each of the drawing means in the 2 nd direction during the movement of the substrate based on the position measured by the position measuring unit so as to reduce the positional error of the pattern drawn by each of the drawing means with respect to the exposure target area; and a 2 nd adjustment member for adjusting the position of the light spot based on each of the drawing units in the 2 nd direction in response to the 1 st adjustment member during the movement of the substrate so as to reduce a bonding error in the 2 nd direction of the pattern drawn by each of the drawing units.

A 2 nd aspect of the present invention is a pattern drawing method of scanning a light spot of a drawing beam projected from each of a plurality of drawing units arranged along a 1 st direction on a substrate in the 1 st direction, moving the substrate in a 2 nd direction intersecting the 1 st direction, and bonding and drawing a pattern drawn by each of the plurality of drawing units in the 1 st direction, the pattern drawing method including: a measurement step of detecting a position of a reference pattern formed on the substrate during movement of the substrate, and measuring a position of an exposed region on the substrate; a 1 st adjustment step of adjusting the position of the light spot on the substrate in the 2 nd direction during the movement of the substrate by the drawing means so as to align the pattern drawn by the drawing means with the exposed region based on the position measured in the measurement step; and a 2 nd adjustment step of adjusting the position of the light spot by each of the drawing means in the 2 nd direction more finely than in the 1 st adjustment step so as to reduce a bonding error in the 2 nd direction of the pattern drawn by each of the drawing means.

A 3 rd aspect of the present invention is a pattern drawing device comprising: a rotary polygon mirror that performs one-dimensional scanning in a main scanning direction of a drawing light beam subjected to intensity modulation according to a pattern to be drawn on a substrate; and a scanning optical system for condensing the one-dimensional scanned drawing beam onto the substrate in the form of a spot; and a pattern is drawn on the substrate by scanning the light spot in the main scanning direction and by relative movement between the substrate and the light spot in a sub-scanning direction intersecting the main scanning direction, the pattern drawing device comprising: a 1 st adjustment means of mechanical optics, which is arranged in an optical path of the drawing beam before being incident on the rotary polygon mirror or in an optical path of the drawing beam from the rotary polygon mirror to the substrate, for adjusting a position of the light spot for one-dimensional scanning in the main scanning direction in the sub-scanning direction; and a 2 nd adjustment member of the photoelectric property, which is disposed in an optical path of the drawing beam before the light enters the rotary polygon mirror and in an optical path in front of the 1 st adjustment member, for adjusting a position of the light spot, which is one-dimensionally scanned in the main scanning direction, in the sub scanning direction.

Drawings

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

Fig. 2 is a configuration diagram showing the configuration of the exposure apparatus of fig. 1.

Fig. 3 is a detailed view showing a state in which the substrate is wound around the rotating drum shown in fig. 2.

Fig. 4 is a diagram showing a drawing line of a light spot scanned on a substrate and an alignment mark formed on the substrate.

Fig. 5 is a view showing an optical configuration of the scanning unit shown in fig. 2.

Fig. 6 is a configuration diagram of the beam switching unit shown in fig. 2.

Fig. 7 is a diagram showing the structure of the light source device shown in fig. 2.

FIG. 8 is a timing chart showing the clock signal generated by the signal generating section in the light source device shown in FIG. 7 and depicting the relationship between the bit string data and the light beam emitted from the polarization beam splitter.

Fig. 9 is a block diagram showing the configuration of an electrical control system of the exposure apparatus shown in fig. 2.

Fig. 10 is a timing chart showing an origin signal output from the origin sensor in the scanning unit shown in fig. 5 and an incidence permission signal generated by the selection element drive control unit shown in fig. 9 based on the origin signal.

Fig. 11 is a block diagram showing the configuration of the signal generating section in the light source device shown in fig. 2.

Fig. 12 is a timing chart showing signals output from each section of the signal generating section shown in fig. 11.

Fig. 13A of fig. 13 is a diagram illustrating a pattern drawn when the partial magnification correction is not performed, and fig. 13B of fig. 13 is a diagram illustrating a pattern drawn when the partial magnification correction (reduction) is performed according to the timing chart shown in fig. 12.

Fig. 14 is a diagram showing a configuration of a beam switching unit according to modification 1 provided in place of the optical element for selection in embodiment 1.

Fig. 15 is a diagram showing the configuration of the beam switching unit according to modification 2 in the case of replacing the selection optical element in the beam switching unit shown in fig. 6 with modification 1 of fig. 14.

Fig. 16 is a diagram showing a detailed optical arrangement of a beam shifter incorporated in the beam switching unit of modification 2 shown in fig. 15.

Fig. 17A of fig. 17 shows a prism-shaped photocell used as a substitute for the optical element for selection in modification 3, and fig. 17B of fig. 17 shows another photocell.

Fig. 18 is a diagram showing in detail the configuration of the wavelength conversion unit in the pulse light generation unit of the light source device according to embodiment 2.

Fig. 19 is a view showing an optical path of a light flux from the light source device to the first optical element for selection in embodiment 2.

Fig. 20 is a diagram showing the configuration of the optical path from the selection optical element to the next selection optical element and the driving circuit of the selection optical element in embodiment 2.

Fig. 21 is a diagram illustrating a case of beam selection and beam shift in the unit-side incident mirror for selection after the optical element for selection in embodiment 2.

Fig. 22 is a diagram illustrating an operation of a light beam from the polygon mirror to the substrate in embodiment 2.

Fig. 23 is a diagram showing a specific configuration of the scanning unit in embodiment 3.

Fig. 24A of fig. 24 is a diagram illustrating a case where the beam position is adjusted by the parallel flat plate provided in the scanner unit shown in fig. 23, and is a diagram illustrating a state where the incident surface and the emission surface of the parallel flat plate parallel to each other are 90 degrees with respect to the center line (principal ray) of the beam, and fig. 24B of fig. 24 is a diagram illustrating a case where the beam position is adjusted by the parallel flat plate provided in the scanner unit shown in fig. 23, and is a diagram illustrating a state where the incident surface and the emission surface of the parallel flat plate parallel to each other are inclined from 90 degrees with respect to the center line (principal ray) of the beam.

Fig. 25 is a block diagram showing a schematic configuration of a control device of the control pattern drawing device according to embodiment 4.

Fig. 26 is a diagram schematically showing an enlarged state of a light beam in a part of the optical paths within the scanning unit (drawing unit) shown in fig. 23.

Fig. 27 is a diagram showing an optical system arrangement from a polygon mirror of the scanning unit (drawing unit) shown in fig. 23 to a substrate.

Detailed Description

The pattern drawing device and pattern drawing method according to the aspects of the present invention will be described in detail below while disclosing preferred embodiments thereof with reference to the accompanying drawings. The aspects of the present invention are not limited to the embodiments, and various modifications and improvements are also included. That is, the constituent elements described below include those which can be easily conceived by a person having ordinary skill in the art to which the invention pertains, and are substantially the same, and the constituent elements described below can be appropriately combined. Various omissions, substitutions, and changes in the constituent elements may be made without departing from the spirit of the invention.

[ embodiment 1 ]

Fig. 1 is a diagram showing a schematic configuration of a device manufacturing system 10 including an exposure apparatus EX for performing an exposure process on a substrate (object to be irradiated) P according to embodiment 1. In the following description, unless otherwise specified, an XYZ orthogonal coordinate system in which the gravitational direction is the Z direction is set, and the X direction, the Y direction, and the Z direction are described by the illustrated arrows.

The device manufacturing system 10 is a system (substrate processing apparatus) for manufacturing an electronic device by performing a specific process (exposure process or the like) on the substrate P. The device manufacturing system 10 is a manufacturing system that is configured with a manufacturing line for manufacturing, for example, a flexible display, a film-shaped touch panel, a film-shaped color filter for a liquid crystal display panel, a flexible wiring, or a flexible sensor, which are electronic devices. Hereinafter, a flexible display will be described as an electronic device. Examples of the flexible display include an organic EL display and a liquid crystal display. The device manufacturing system 10 has a structure of a so-called Roll-To-Roll (Roll toll) system as follows: the substrate P is fed from a supply reel FR1 that winds a flexible sheet-like substrate (sheet substrate) P into a roll, various treatments are continuously performed on the fed substrate P, and then the various treated substrates P are wound up by a recovery reel FR 2. The substrate P has a strip shape in which the moving direction (conveying direction) of the substrate P is the long side direction (long strip) and the width direction is the short side direction (short strip). In embodiment 1, the film-like substrate P is wound around the recovery roll FR2 by passing through at least the processing apparatus (processing apparatus 1) PR1, the processing apparatus (processing apparatus 2) PR2, the exposure apparatus (processing apparatus 3) EX, the processing apparatus (processing apparatus 4) PR3, and the processing apparatus (processing apparatus 5) PR 4.

In embodiment 1, the X direction is a direction (conveying direction) in which the substrate P is fed from the supply reel FR1 toward the recovery reel FR2 in the horizontal plane. The Y direction is a direction orthogonal to the X direction in the horizontal plane, and is a width direction (stripe direction) of the substrate P. The Z direction is a direction (upward direction) orthogonal to the X direction and the Y direction, and is parallel to the direction in which gravity acts.

For example, a resin film, a foil (metal foil) made of a metal or alloy such as stainless steel, or the like is used as the substrate P. As a material of the resin film, for example, at least 1 or more of 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 rigidity (young's modulus) of the substrate P may be in a range in which no crease or irreversible crease is generated in the substrate P due to buckling when the substrate P passes through the conveyance path of the device manufacturing system 10. As a base material of the substrate P, a film of PET (polyethylene terephthalate) or PEN (polyethylene naphthalate) or the like having a thickness of about 25 μm to 200 μm is typical of a preferable sheet substrate.

The substrate P is sometimes subjected to heat in each process performed by the processing apparatus PR1, the processing apparatus PR2, the exposure apparatus EX, the processing apparatus PR3, and the processing apparatus PR4, and therefore, it is preferable to select a substrate P whose thermal expansion is a material whose number is not significantly large. For example, thermal expansion can be suppressed by mixing an inorganic filler into the resin film. The inorganic filler may also be, for example, titanium oxide, zinc oxide, aluminum oxide, or silicon oxide. The substrate P may be a single layer of extremely thin glass having a thickness of about 100 μm manufactured by a float method or the like, or may be a laminate of the extremely thin glass and the resin film, foil or the like.

The flexibility (flexibility) of the substrate P means a property that the substrate P can be bent without shearing or breaking even when a force of a degree of self weight is applied to the substrate P. The bending property by the force of the self-weight degree is also included in the flexibility. The degree of flexibility varies depending on the material, size, thickness, layer structure formed on the substrate P, temperature, humidity, and other conditions of the substrate P. In general, when the substrate P is accurately wound around the various conveying rollers, rotating drums, or other conveying direction switching members provided in the conveying path in the device manufacturing system 10 according to embodiment 1, the substrate P can be smoothly conveyed without buckling, leaving a crease, or without breakage (occurrence of breakage or cracking), and may be referred to as a flexible range.

The processing apparatus PR1 is a coating apparatus that performs a coating process on the substrate P while conveying the substrate P conveyed from the supply roll FR1 toward the processing apparatus PR2 at a specific speed along a conveyance direction (+x direction) along the longitudinal direction. The processing apparatus PR1 selectively or uniformly applies a photosensitive functional liquid to the surface of the substrate P. The substrate P coated with the photosensitive functional liquid on the surface is transported toward the processing apparatus PR 2.

The processing apparatus PR2 is a drying apparatus that performs a drying process on the substrate P while conveying the substrate P conveyed from the processing apparatus PR1 in a conveying direction (+x direction) toward the exposure apparatus EX at a specific speed. The processing apparatus PR2 dries the photosensitive functional liquid by removing solvent or water contained in the photosensitive functional liquid by a blower that blows drying air (warm air), such as hot air or dry air, to the surface of the substrate P, an infrared light source, a ceramic heater, or the like. Thus, a film to be a photosensitive functional layer (photosensitive layer) is selectively or uniformly formed on the surface of the substrate P. Further, a photosensitive functional layer may be formed on the surface of the substrate P by attaching a dry film to the surface of the substrate P. In this case, an attaching device (processing device) for attaching the dry film to the substrate P may be provided instead of the processing devices PR1 and PR 2.

Here, the photosensitive functional liquid (layer) is typically a photoresist (liquid or dry film), and as a material that does not require development treatment, there are a photosensitive silane coupling agent (SAM) that is modified in affinity and hydrophobicity in a portion irradiated with ultraviolet rays, a photosensitive reducing agent that is exposed to a plating reducing group in a portion irradiated with ultraviolet rays, and the like. When a photosensitive silane coupling agent is used as the photosensitive functional liquid (layer), the pattern portion on the substrate P after exposure to ultraviolet rays is modified from lyophobic to lyophilic. Therefore, by selectively applying a liquid containing a conductive ink (an ink containing conductive nanoparticles such as silver or copper) or a semiconductor material to a portion which becomes lyophilic, a pattern layer which forms an electrode, a semiconductor, or a wiring for insulation or connection of a Thin Film Transistor (TFT) or the like can be formed. When a photosensitive reducing agent is used as the photosensitive functional liquid (layer), a reducing group is exposed by plating on the pattern portion of the substrate P after exposure to ultraviolet rays. Therefore, the substrate P is immersed in a plating solution containing palladium ions or the like for a fixed time immediately after exposure, whereby a pattern layer of palladium is formed (deposited). Such a plating process is an additive process, and may be also used as an etching process in a subtractive process. In this case, the substrate P conveyed to the exposure apparatus EX may be obtained by forming a base material of PET or PEN, depositing a metallic thin film of aluminum (Al) or copper (Cu) on the entire surface thereof or selectively depositing a photoresist layer thereon. In embodiment 1, a photosensitive reducing agent is used as the photosensitive functional liquid (layer).

The exposure apparatus EX is a processing apparatus that performs exposure processing on the substrate P while conveying the substrate P conveyed from the processing apparatus PR2 toward the processing apparatus PR3 at a specific speed in a conveying direction (+x direction). The exposure apparatus EX irradiates the surface (i.e., the photosensitive surface) of the substrate P with a light pattern corresponding to a pattern for an electronic device (e.g., a pattern of an electrode, wiring, or the like of a TFT constituting the electronic device). Thereby, a latent image (modified portion) corresponding to the pattern is formed on the photosensitive functional layer.

In embodiment 1, the exposure apparatus EX is a direct-scanning exposure apparatus using no mask, or a so-called raster-scanning exposure apparatus (pattern drawing apparatus). As will be described in detail later, the exposure apparatus EX scans (main scans) the spot SP of the pulse beam LB (pulse beam) for exposure one-dimensionally in a specific scanning direction (Y direction) on the surface to be irradiated (photosurface) of the substrate P while conveying the substrate P in the +x direction (subscanning direction), and rapidly modulates (on/off) the intensity of the spot SP in accordance with pattern data (drawing data, pattern information). By this, a light pattern corresponding to a specific pattern of an electronic device, a circuit, a wiring, or the like is drawn and exposed on the irradiated surface of the substrate P. Specifically, the spot SP is scanned in two dimensions on the surface of the substrate P to be irradiated by the sub-scanning of the substrate P and the main scanning of the spot SP, and a specific pattern is drawn and exposed on the substrate P. Since the substrate P is conveyed in the conveyance direction (+x direction), a plurality of exposure regions W of the exposure pattern are provided at specific intervals along the longitudinal direction of the substrate P by the exposure apparatus EX (see fig. 4). Since the electronic device is formed in the exposed region W, the exposed region W is also a device formation region. Further, the electronic device is configured by overlapping a plurality of pattern layers (layers on which patterns are formed), and thus, patterns corresponding to the respective layers may be exposed by the exposure apparatus EX.

The processing apparatus PR3 is a wet processing apparatus that performs wet processing on the substrate P while conveying the substrate P conveyed from the exposure apparatus EX toward the processing apparatus PR4 at a specific speed in a conveying direction (+x direction). In embodiment 1, the processing apparatus PR3 performs a plating process, which is one type of wet process, on the substrate P. That is, the substrate P is immersed in the plating solution stored in the processing bath for a specific time. Thereby, a pattern layer corresponding to the latent image is deposited (formed) on the surface of the photosensitive functional layer. That is, a specific material (for example, palladium) is selectively formed on the substrate P according to the difference between the irradiated portion and the non-irradiated portion of the spot SP on the photosensitive functional layer of the substrate P, which becomes a pattern layer.

When a photosensitive silane coupling agent is used as the photosensitive functional layer, a coating process or a plating process of a liquid (for example, a liquid containing conductive ink or the like) which is one of wet processes is performed by the processing device PR 3. In this case, a pattern layer corresponding to the latent image is formed on the surface of the photosensitive functional layer. Specifically, a specific material (for example, conductive ink, palladium, or the like) is selectively formed on the substrate P according to the difference between the irradiated portion and the irradiated portion of the light spot SP of the photosensitive functional layer of the substrate P, and this becomes a pattern layer. In the case of using a photoresist as the photosensitive functional layer, a development treatment, which is one of wet treatments, is performed by the processing device PR 3. In this case, a pattern corresponding to the latent image is formed on the photosensitive functional layer (photoresist) by the development treatment.

The processing apparatus PR4 is a cleaning/drying apparatus that cleans and dries the substrate P while conveying the substrate P conveyed from the processing apparatus PR3 toward the recovery reel FR2 at a specific speed in the conveying direction (+x direction). The processing apparatus PR4 cleans the wet-processed substrate P with pure water, and then dries the substrate P at a glass transition temperature or lower until the water content of the substrate P becomes a predetermined value or lower.

In the case of using a photosensitive silane coupling agent as the photosensitive functional layer, the processing apparatus PR4 may be an annealing/drying apparatus that performs annealing and drying on the substrate P. The annealing treatment irradiates the substrate P with high-brightness pulsed light, for example, from a flash lamp, in order to consolidate the electrical bonding of the nanoparticles contained in the applied conductive ink. When a photoresist is used as the photosensitive functional layer, a processing device (wet processing device) PR5 for performing etching processing and a processing device (cleaning/drying device) PR6 for cleaning/drying the substrate P subjected to etching processing may be provided between the processing device PR4 and the recovery reel FR 2. Thus, in the case of using a photoresist as the photosensitive functional layer, a pattern layer is formed on the substrate P by performing an etching process. Specifically, a specific material (for example, aluminum (Al) or copper (Cu)) is selectively formed on the substrate P according to the difference between the irradiated portion and the irradiated portion of the light spot SP of the photosensitive functional layer of the substrate P, and this becomes a pattern layer. The processing apparatuses PR5 and PR6 have a function of conveying the substrate P in the conveyance direction (+x direction) at a specific speed toward the recovery reel FR2 with respect to the conveyed substrate P. The plurality of processing apparatuses PR1 to PR4 (and processing apparatuses PR5 and PR6, as necessary) are configured as a substrate conveying apparatus that conveys the substrate P in the +x direction.

In this way, the substrates P subjected to the respective treatments are recovered by the recovery reel FR 2. At least each process of the device manufacturing system 10 forms 1 pattern layer on the substrate P. As described above, the electronic device is constructed by overlapping a plurality of pattern layers, and thus, in order to produce the electronic device, each process of the device manufacturing system 10 shown in fig. 1 must be performed at least 2 times. Accordingly, the pattern layer can be laminated by mounting the recovery reel FR2 around which the substrate P is wound as the supply reel FR1 to another device manufacturing system 10. The above-described operations are repeated to form an electronic device. The processed substrate P is in a state in which a plurality of electronic devices are connected to each other along the longitudinal direction of the substrate P at specific intervals. That is, the substrate P serves as a plurality of substrates for obtaining a plurality of substrates.

The recovery reel FR2 that recovers the substrates P on which the electronic devices are formed in a connected state may be mounted on a dicing device, not shown. The dicing apparatus mounted with the recovery reel FR2 divides (cuts) the processed substrate P in units of electronic devices (the exposed regions W as device forming regions), thereby forming a plurality of electronic devices as a single piece. The dimension of the substrate P is, for example, about 10cm to 2m in the width direction (direction of the short strip), and 10m or more in the length direction (direction of the long strip). The size of the substrate P is not limited to the above-described size.

Fig. 2 is a configuration diagram showing the configuration of the exposure apparatus EX. The exposure apparatus EX is housed in a temperature control chamber ECV. The temperature control chamber ECV is configured to suppress a change in shape of the substrate P conveyed therein due to temperature by keeping the inside at a specific temperature and a specific humidity, and is set to a humidity that takes into consideration hygroscopicity of the substrate P, electrification of static electricity generated by conveyance, and the like. The temperature control chamber ECV is installed on the installation surface E of the manufacturing plant via passive or active vibration isolation units SU1 and SU 2. The vibration preventing units SU1, SU2 reduce vibrations from the installation surface E. The installation surface E may be the floor surface itself of the factory or may be an installation base (pedestal) that is installed exclusively on the floor surface in order to form a horizontal plane. The exposure apparatus EX includes at least a substrate conveyance mechanism 12, 2 light source devices (light sources) LS (LSa, LSb) having the same configuration, a beam switching unit (including a photoelectric deflecting device) BDU, an exposure head (scanning device) 14, a control device 16, a plurality of alignment microscopes AM1m, AM2m (m=1, 2, 3, 4), and a plurality of encoders ENja, ENjb (j=1, 2, 3, 4). The control device (control unit) 16 controls each unit of the exposure device EX. The control device 16 includes a computer, a recording medium on which programming is recorded, and the like, and the control device 16 according to embodiment 1 functions as a control device by executing programming by the computer.

The substrate transfer mechanism 12 is a part of the substrate transfer apparatus constituting the device manufacturing system 10, and transfers the substrate P transferred from the processing apparatus PR2 into the exposure apparatus EX at a specific speed and then out to the processing apparatus PR3 at a specific speed. The substrate conveying mechanism 12 defines a conveying path of the substrate P conveyed in the exposure apparatus EX. The substrate conveying mechanism 12 includes an edge position controller EPC, a driving roller R1, a tension adjusting roller RT1, a rotating drum (cylindrical drum) DR, a tension adjusting roller RT2, a driving roller R2, and a driving roller R3 in this order from the upstream side (-X direction side) in the conveying direction of the substrate P.

The edge position controller EPC adjusts the position in the width direction of the substrate P (Y direction and short direction of the substrate P) conveyed from the processing apparatus PR 2. That is, the edge position controller EPC adjusts the position of the substrate P in the width direction by moving the substrate P in the width direction such that the position of the end (edge) of the substrate P in the width direction, which is conveyed in a state where a specific tension is applied, is controlled to be within a range (allowable range) of about ±tens μm to several tens μm with respect to the target position. The edge position controller EPC includes rollers for erecting the substrate P in a state where a specific tension is applied thereto, and an edge sensor (end detection unit), not shown, for detecting the position of the end (edge) of the substrate P in the width direction. The edge position controller EPC moves the roller of the edge position controller EPC in the Y direction based on the detection signal detected by the edge sensor, and adjusts the position of the substrate P in the width direction. The driving roller (pinch roller) R1 rotates the front and back surfaces of the substrate P conveyed from the edge position controller EPC while holding the substrate P, and conveys the substrate P toward the rotating drum DR. The edge position controller EPC may be appropriately adjusted to the position in the width direction of the substrate P so that the longitudinal direction of the substrate P wound around the rotating drum DR is always orthogonal to the central axis AXo of the rotating drum DR, and the parallelism between the rotation axis of the roller and the Y axis of the edge position controller EPC may be appropriately adjusted so as to correct the inclination error in the advancing direction of the substrate P.

The rotary drum DR has a central shaft AXo extending in the Y direction and extending in a direction intersecting the direction in which gravity acts, and a cylindrical outer peripheral surface having a fixed radius from the central shaft AXo. The rotating drum DR is supported (held) by bending a part of the substrate P into a cylindrical shape in the longitudinal direction according to the outer peripheral surface (circumferential surface), and rotates around the central axis AXo to convey the substrate P in the +x direction. The rotating drum DR is an area (portion) on the outer peripheral surface of which the substrate P is supported for projection by the light beam LB (spot SP) from the exposure head 14. The rotating drum DR supports (holds in close contact with) the substrate P from the side (back) opposite to the side on which the electronic device is formed (side on which the photosensitive surface is formed). On both sides of the rotating drum DR in the Y direction, a long rod Sft supported by an annular bearing is provided so that the rotating drum DR rotates around the central shaft AXo. The long rod Sft rotates around the central shaft AXo at a fixed rotational speed by torque applied from a rotational drive source (not shown) (e.g., a motor, a reduction mechanism, etc.) controlled by the control device 16. For convenience, a plane including the central axis AXo and parallel to the YZ plane is referred to as a center plane Poc.

The driving rollers (pinch rollers) R2 and R3 are disposed at a specific interval along the conveyance direction (+x direction) of the substrate P, and impart a specific relaxation (play) to the exposed substrate P. The driving rollers R2 and R3 rotate while holding the front and back surfaces of the substrate P, and convey the substrate P toward the processing apparatus PR3, as in the driving roller R1. The tension adjusting rollers RT1 and RT2 are biased in the-Z direction, and apply a specific tension to the substrate P wound around and supported by the rotating drum DR in the longitudinal direction. Thereby, the tension in the longitudinal direction applied to the substrate P held by the rotating drum DR is stabilized within a specific range. The control device 16 controls a rotational drive source (not shown) (e.g., a motor, a speed reducer, etc.) to rotate the drive rollers R1 to R3. The rotation axes of the driving rollers R1 to R3 and the rotation axes of the tension adjusting rollers RT1 and RT2 are parallel to the central axis AXo of the rotary drum DR.

The light source devices LS (LSa, LSb) generate and emit pulsed light beams (pulsed light beam, pulsed light, laser light) LB. The light beam LB is ultraviolet light having a peak wavelength in a wavelength band of 370nm or less, and the light emission frequency (oscillation frequency, specific frequency) of the light beam LB is Fa. The light beam LB emitted from the light source device LS (LSa, LSb) enters the exposure head 14 via the beam switching unit BDU. The light source devices LS (LSa, LSb) emit light at the light emission frequency Fa and emit the light beam LB under the control of the control device 16. In embodiment 1, the configuration of the light source device LS (LSa, LSb) is described in detail below, and the configuration is configured by a semiconductor laser element that generates pulse light in the infrared wavelength region, an optical fiber amplifier, a wavelength conversion element (harmonic generation element) that converts amplified pulse light in the infrared wavelength region into pulse light in the ultraviolet wavelength region, and the like, and an optical fiber amplifier laser light source (harmonic laser light source) that uses pulse light that obtains ultraviolet light with a high brightness, in which the oscillation frequency Fa is hundreds MHz and the light emission time of 1 pulse light is about picoseconds, is used. In order to distinguish the light beam LB from the light source device LSa from the light beam LB from the light source device LSb, the light beam LB from the light source device LSa may be denoted by LBa, and the light beam LB from the light source device LSb may be denoted by LBb.

The beam switching unit BDU makes the beams LB (LBa, LBb) from the 2 light source devices LS (LSa, LSb) incident on 2 scanning units Un (n=1, 2, …, 6) out of the plurality of scanning units Un (n=1, 2, …, 6) constituting the exposure head 14, and switches the scanning units Un on which the beams LB (LBa, LBb) are incident. Specifically, the beam switching unit BDU makes the light beam LBa from the light source device LSa enter 1 scanning unit Un of the 3 scanning units U1 to U3, and makes the light beam LBb from the light source device LSb enter 1 scanning unit Un of the 3 scanning units U4 to U6. The beam switching unit BDU switches the scanning unit Un on which the beam LBa is incident from among the scanning units U1 to U3, and switches the scanning unit Un on which the beam LBb is incident from among the scanning units U4 to U6.

The beam switching unit BDU switches the scanning unit Un to which the light beams LBa and LBb are incident so that the light beam LBn is incident on the scanning unit Un (drawing unit) that scans the light spot SP. That is, the beam switching unit BDU makes the light beam LBa from the light source device LSa enter 1 scanning unit Un that scans the spot SP among the scanning units U1 to U3. Similarly, the beam switching unit BDU makes the light beam LBb from the light source device LSb enter 1 scanning unit Un that scans the spot SP among the scanning units U4 to U6. The beam switching unit BDU will be described in detail below. The scanning units U1 to U3 are switched in the order of U1, U2, and U3, and the scanning units U4 to U6 are switched in the order of U4, U5, and U6. The above configuration of the beam switching unit BDU or the light source device LS (LSa, LSb) is disclosed in, for example, international publication No. 2015/166910, and will be described in detail below with reference to fig. 6 and 7.

The exposure head 14 is a so-called multi-beam type exposure head in which a plurality of scanning units Un (U1 to U6) having the same configuration are arranged. The exposure head 14 is configured to draw a pattern on a part of the substrate P supported by the outer peripheral surface (circumferential surface) of the rotary drum DR by a plurality of scanning units Un (U1 to U6). Since the exposure head 14 repeatedly exposes the substrate P with the pattern for the electronic device, a plurality of exposure regions (electronic device forming regions) W of the exposure pattern are provided at specific intervals along the longitudinal direction of the substrate P (see fig. 4). The plurality of scanning units Un (U1 to U6) are arranged in a specific arrangement relationship. The plurality of scanning units Un (U1 to U6) are arranged in 2 rows staggered in the conveyance direction of the substrate P with the center plane Poc interposed therebetween. The odd-numbered scanning units U1, U3, and U5 are arranged on the upstream side (-X direction side) of the center plane Poc in the conveyance direction of the substrate P, and are arranged in 1 row at a specific interval along the Y direction. The even number of scanning units U2, U4, and U6 are arranged downstream in the conveyance direction (+x direction side) of the substrate P with respect to the center plane Poc, and are arranged in 1 row at a specific interval along the Y direction. The odd-numbered scanning units U1, U3, U5 and the even-numbered scanning units U2, U4, U6 are symmetrically arranged with respect to the center plane Poc when viewed in the XZ plane.

Each of the scanning units Un (U1 to U6) projects the light beam LB from the light source device LS (LSa, LSb) so as to converge into a light spot SP on the irradiated surface of the substrate P, and scans the light spot SP one-dimensionally by the rotating polygon mirror PM (see fig. 5). The light spot SP is scanned on the irradiated surface of the substrate P in one dimension by a polygon mirror (deflection member) PM of each of the scanning units Un (U1 to U6). By scanning the spot SP, a drawing line (scanning line) SLn (n=1, 2, …, 6) for drawing a straight line corresponding to a pattern of 1 line is defined on the substrate P (on the irradiated surface of the substrate P). The configuration of the scanner unit Un will be described in detail below.

The scanning unit U1 scans the spot SP along the drawing line SL1, and similarly, the scanning units U2 to U6 scan the spot SP along the drawing lines SL2 to SL 6. As shown in fig. 3 and 4, the drawing lines SLn (SL 1 to SL 6) of the plurality of scanning units Un (U1 to U6) are set so as not to be separated from each other in the Y direction (the width direction of the substrate P, the main scanning direction). The light beam LB from the light source device LS (LSa, LSb) incident on the scanning unit Un through the light beam switching unit BDU is sometimes denoted as LBn. Note that, in some cases, the light beam LBn incident on the scanner unit U1 is denoted by LB1, and similarly, the light beams LBn incident on the scanner units U2 to U6 are denoted by LB2 to LB 6. The drawing lines SLn (SL 1 to SL 6) indicate the scanning tracks of the spots SP of the light beams LBn (LB 1 to LB 6) scanned by the scanning units Un (U1 to U6). The light beam LBn incident on the scanning unit Un may be a light beam of linearly polarized light (P-polarized light or S-polarized light) polarized in a specific direction, and in embodiment 1, the light beam is P-polarized light.

As shown in fig. 4, the scanning units Un (U1 to U6) share the scanning area so that the entire scanning units Un (U1 to U6) cover the entire width direction of the exposure target area W. Thus, each of the scanning units Un (U1 to U6) can draw a pattern for each of a plurality of areas (drawing ranges) divided in the width direction of the substrate P. For example, if the scanning length in the Y direction (length of the drawing line SLn) of 1 scanning unit Un is about 20 to 60mm, the width in the Y direction that can be drawn is enlarged to about 120 to 360mm by arranging 6 scanning units Un, which are 3 of the odd-numbered scanning units U1, U3, and U5 and 3 of the even-numbered scanning units U2, U4, and U6, in total, in the Y direction. The length (length of drawing range) of each drawing line SLn (SL 1 to SL 6) is basically the same. That is, the scanning distance of the spot SP of the light beam LBn scanned along each of the drawing lines SL1 to SL6 is basically the same. Further, in the case of expanding the width of the exposure region W, it is possible to cope with the expansion of the length of the drawing line SLn itself or the increase of the number of scanning units Un arranged in the Y direction.

The actual drawing lines SLn (SL 1 to SL 6) are set to be slightly shorter than the maximum length (maximum scanning length) that the spot SP can actually scan on the irradiation surface. For example, if the scanning length of the drawing line SLn in which pattern drawing is possible when the drawing magnification in the main scanning direction (Y direction) is set to the initial value (no magnification correction) is set to 30mm, the maximum scanning length of the spot SP on the irradiated surface is set to 31mm with a margin of about 0.5mm on the drawing start point (scanning start point) side and the drawing end point (scanning end point) side of the drawing line SLn. By setting the position of the drawing line SLn of 30mm in the main scanning direction within the range of 31mm of the maximum scanning length of the spot SP, the drawing magnification can be finely adjusted. The maximum scanning length of the spot SP is not limited to 31mm, and is mainly determined by the aperture of an fθ lens FT (see fig. 5) provided behind a polygon mirror PM in the scanning unit Un.

The drawing lines SLn (SL 1 to SL 6) are arranged in 2 rows alternately in the circumferential direction of the rotating drum DR with the center plane Poc interposed therebetween. The odd-numbered drawing lines SL1, SL3, and SL5 are located on the irradiated surface of the substrate P on the upstream side (-X direction side) in the conveyance direction of the substrate P with respect to the center plane Poc. The even-numbered drawing lines SL2, SL4, and SL6 are located on the irradiated surface of the substrate P on the downstream side (+x direction side) of the center plane Poc in the conveyance direction of the substrate P. The drawing lines SL1 to SL6 are substantially parallel to the width direction of the substrate P, that is, the central axis AXo of the rotating drum DR.

The drawing lines SL1, SL3, and SL5 are arranged in 1 line at specific intervals along the width direction (main scanning direction) of the substrate P. Similarly, the drawing lines SL2, SL4, and SL6 are arranged in 1 line at a predetermined interval along the width direction (main scanning direction) of the substrate P. At this time, the drawing line SL2 is arranged between the drawing lines SL1 and SL3 in the width direction of the substrate P. Similarly, the drawing line SL3 is disposed between the drawing line SL2 and the drawing line SL4 in the width direction of the substrate P. The drawing line SL4 is disposed between the drawing lines SL3 and SL5 in the width direction of the substrate P, and the drawing line SL5 is disposed between the drawing line SL4 and SL6 in the width direction of the substrate P. As described above, the plurality of drawing lines SLn (SL 1 to SL 6) are arranged so as to be offset from each other in the Y direction (main scanning direction).

The main scanning directions of the spots SP of the light beams LB1, LB3, LB5 scanned along the odd-numbered drawing lines SL1, SL3, SL5 are one-dimensional and the same. The main scanning directions of the spots SP of the light beams LB2, LB4, LB6 scanned along the even-numbered drawing lines SL2, SL4, SL6 are one-dimensional directions and have the same direction. The main scanning directions of the spots SP of the light beams LB1, LB3, LB5 scanning along the drawing lines SL1, SL3, SL5 and the main scanning directions of the spots SP of the light beams LB2, LB4, LB6 scanning along the drawing lines SL2, SL4, SL6 may be opposite to each other. In embodiment 1, the main scanning direction of the spot SP of the light beams LB1, LB3, LB5 scanned along the drawing lines SL1, SL3, SL5 is the-Y direction. The main scanning direction of the spot SP of the light beams LB2, LB4, LB6 scanned along the drawing lines SL2, SL4, SL6 is the +y direction. Thus, the end of the drawing lines SL1, SL3, SL5 on the drawing start point side and the end of the drawing lines SL2, SL4, SL6 on the drawing start point side are adjacent or partially overlapped in the Y direction. The end portions of the drawing lines SL3 and SL5 on the drawing end point side and the end portions of the drawing lines SL2 and SL4 on the drawing end point side are adjacent or partially overlapped in the Y direction. When the drawing lines SLn are arranged such that the end portions of the drawing lines SLn adjacent to each other in the Y direction overlap each other locally, for example, the drawing start point or the drawing end point is preferably overlapped in the Y direction in a range of a few percent or less with respect to the length of each drawing line SLn. Further, joining the drawing lines SLn in the Y direction means that the end portions of the drawing lines SLn are abutted (closely adhered) or partially overlapped with each other in the Y direction.

The width (X-direction dimension) of the drawing line SLn in the sub-scanning direction is a thickness corresponding to the size (diameter) Φ of the light spot SP. For example, when the size (dimension) Φ of the spot SP is 3 μm, the width of the drawing line SLn is also 3 μm. The spot SP may also be projected along the drawing line SLn with overlapping a specific length (for example, 1/2 of the size phi of the spot SP). In the case where the drawing lines SLn (for example, the drawing line SL1 and the drawing line SL 2) adjacent to each other in the Y direction are joined to each other, the predetermined length (for example, 1/2 of the size Φ of the light spot SP) may be overlapped.

In the case of embodiment 1, since the light beams LB (LBa, LBb) from the light source devices LS (LSa, LSb) are pulsed light, the light spots SP projected onto the drawing line SLn during the main scanning become discrete depending on the oscillation frequency Fa (e.g., 400 MHz) of the light beams LB (LBa, LBb). Therefore, it is necessary to overlap the spot SP projected by the 1-pulse light of the light beam LB and the spot SP projected by the next 1-pulse light in the main scanning direction. The amount of overlap is set according to the size phi of the spot SP, the scanning speed (main scanning speed) Vs of the spot SP, and the oscillation frequency Fa of the beam LB. The effective size phi of the spot SP is determined by 1/e2 (or 1/2) of the peak intensity of the spot SP in the case where the intensity distribution of the spot SP is approximated by a gaussian distribution. In embodiment 1, the scanning speed Vs and the oscillation frequency Fa of the spot SP are set so that the spot SP overlaps with the effective size (dimension) Φ by about Φx1/2. Therefore, the projection interval of the spot SP in the main scanning direction becomes Φ/2. Therefore, it is preferable that the substrate P is set so that the substrate P is also moved by a distance of approximately 1/2 of the effective size Φ of the spot SP between 1 scan and the next scan of the spot SP along the drawing line SLn in the sub-scanning direction (the direction orthogonal to the drawing line SLn). The exposure amount of the photosensitive functional layer on the substrate P may be set by adjusting the peak value of the light beam LB (pulse light), but when the exposure amount is to be increased in a case where the intensity of the light beam LB cannot be increased, the amount of overlap in the main scanning direction or the sub scanning direction of the light spot SP may be increased by any of a decrease in the scanning speed Vs in the main scanning direction of the light spot SP, an increase in the oscillation frequency Fa of the light beam LB, or a decrease in the conveyance speed Vt in the sub scanning direction of the substrate P. The scanning speed Vs of the spot SP in the main scanning direction is accelerated in proportion to the rotation number (rotation speed Vp) of the polygon mirror PM.

Each scanning unit Un (U1 to U6) irradiates each light beam LBn toward the substrate P so that each light beam LBn advances toward the central axis AXo of the rotating drum DR at least in the XZ plane. Thus, the optical path (beam center axis) of the light beam LBn advancing from each scanning unit Un (U1 to U6) toward the substrate P is parallel to the normal line of the irradiated surface of the substrate P in the XZ plane. Each of the scanning units Un (U1 to U6) irradiates the light beam LBn toward the substrate P so that the light beam LBn irradiated to the drawing lines SLn (SL 1 to SL 6) is perpendicular to the irradiated surface of the substrate P in the plane parallel to the YZ plane. That is, in the main scanning direction of the spot SP on the irradiated surface, the light fluxes LBn (LB 1 to LB 6) projected onto the substrate P are scanned in a telecentric state. Here, a line (or also referred to as an optical axis) passing through each midpoint of the specific drawing lines SLn (SL 1 to SL 6) defined by each scanning unit Un (U1 to U6) and perpendicular to the irradiated surface of the substrate P is referred to as an irradiation center axis Len (Le 1 to Le 6).

The irradiation center axes Len (Le 1 to Le 6) are lines connecting the drawing lines SL1 to SL6 with the center axis AXo in the XZ plane. The irradiation central axes Le1, le3, le5 of the odd-numbered scanning units U1, U3, U5 are in the same direction in the XZ plane, and the irradiation central axes Le2, le4, le6 of the even-numbered scanning units U2, U4, U6 are in the same direction in the XZ plane. The irradiation center axes Le1, le3, le5 and the irradiation center axes Le2, le4, le6 are set so that the angles with respect to the center plane Poc in the XZ plane become ±θ1 (see fig. 2).

The alignment microscopes AM1m (AM 11 to AM 14) and AM2m (AM 21 to AM 24) shown in fig. 2 are provided in plural (4 in embodiment 1) along the Y direction for detecting the alignment marks MKm (MK 1 to MK 4) formed on the substrate P shown in fig. 4. The plurality of alignment marks MKm (MK 1 to MK 4) are reference marks for aligning (aligning) a specific pattern drawn on the exposure target area W on the irradiated surface of the substrate P with respect to the substrate P. The alignment microscopes AM1m (AM 11 to AM 14) and AM2m (AM 21 to AM 24) detect the alignment marks MKm (MK 1 to MK 4) on the substrate P supported by the outer peripheral surface (circumferential surface) of the rotating drum DR. The alignment microscopes AM1m (AM 11 to AM 14) are provided on the upstream side (-X direction side) in the conveyance direction of the substrate P than the irradiated region (region surrounded by the drawing lines SL1 to SL 6) on the substrate P based on the light spot SP of the light beams LBn (LB 1 to LB 6) from the exposure head 14. The alignment microscopes AM2m (AM 21 to AM 24) are provided on the downstream side (+x direction side) in the conveyance direction of the substrate P than the irradiated region (region surrounded by the drawing lines SL1 to SL 6) on the substrate P based on the light spot SP of the light beams LBn (LB 1 to LB 6) from the exposure head 14.

The alignment microscopes AM1m (AM 11 to AM 14) and AM2m (AM 21 to AM 24) have: a light source that projects illumination light for alignment toward the substrate P; an observation optical system (including an objective lens) that obtains an enlarged image of a partial region (observation region) Vw1m (Vw 11 to Vw 14) and Vw2m (Vw 21 to Vw 24) including an alignment mark MKm on the surface of the substrate P; and an imaging device such as a CCD or CMOS that captures the magnified image by a high-speed shutter corresponding to the transport speed Vt of the substrate P while the substrate P is moving in the transport direction. The imaging signals (image data) captured by the respective alignment microscopes AM1m (AM 11 to AM 14) and AM2m (AM 21 to AM 24) are transmitted to the control device 16. The mark position detecting unit 106 (see fig. 9) of the control device 16 detects the positions (mark position information) of the alignment marks MKm (MK 1 to MK 4) on the substrate P by performing image analysis of the transmitted plurality of imaging signals. The illumination light for alignment is light in a wavelength region having little sensitivity to the photosensitive functional layer on the substrate P, for example, light having a wavelength of about 500 to 800 nm.

The plurality of alignment marks MK1 to MK4 are provided around the respective exposed regions W. The alignment marks MK1 and MK4 are formed at a plurality of intervals Dh along the longitudinal direction of the substrate P on both sides of the width direction of the substrate P in the exposure region W. The alignment mark MK1 is formed on the-Y direction side of the width direction of the substrate P, and the alignment mark MK4 is formed on the +y direction side of the width direction of the substrate P. The alignment marks MK1 and MK4 are arranged so as to be positioned at the same position in the longitudinal direction (X direction) of the substrate P in a state where the substrate P is not subjected to a large tensile force or is not deformed by a thermal process. The alignment marks MK2 and MK3 are blank portions formed between the alignment marks MK1 and MK4 along the width direction (the stripe direction) of the substrate P and on the +x direction side and the-X direction side of the exposure target area W. The alignment marks MK2, MK3 are formed between the exposed region W and the exposed region W. The alignment mark MK2 is formed on the-Y direction side of the width direction of the substrate P, and the alignment mark MK3 is formed on the +y direction side of the substrate P.

Further, the Y-direction interval between the alignment mark MK1 and the alignment mark MK2 arranged at the end of the substrate P in the-Y direction, the Y-direction interval between the alignment mark MK2 and the alignment mark MK3 arranged at the end of the substrate P in the +y direction, and the Y-direction interval between the alignment mark MK4 and the alignment mark MK3 arranged at the end of the substrate P in the +y direction are set to be the same distance. The alignment marks MKm (MK 1 through MK 4) may also be formed together when forming the 1 st pattern layer. For example, when exposing the pattern of layer 1, the pattern for the alignment mark may be exposed around the exposed area W of the exposure pattern. Furthermore, the alignment mark MKm can be formed in the exposed area W. For example, the exposure region W may be formed along the outline of the exposure region W. Also, a pattern portion formed at a specific position or a portion of a specific shape in the pattern of the electronic device within the exposure target area W may be used as the alignment mark MKm.

As shown in fig. 4, the alignment microscopes AM11 and AM21 are arranged to capture an alignment mark MK1 existing in the observation regions (detection regions) Vw11 and Vw21 of the objective lens. Similarly, the alignment microscopes AM12 to AM14 and AM22 to AM24 are arranged to capture alignment marks MK2 to MK4 existing in the observation regions Vw12 to Vw14 and Vw22 to Vw24 of the objective lens. Therefore, the plurality of alignment microscopes AM11 to AM14, AM21 to AM24 are positioned corresponding to the plurality of alignment marks MK1 to MK4, and are provided along the width direction of the substrate P in the order AM11 to AM14, AM21 to AM24 from the-Y direction side of the substrate P. In fig. 3, the observation regions Vw2m (Vw 21 to Vw 24) of the alignment microscope AM2m (AM 21 to AM 24) are not shown.

The plurality of alignment microscopes AM1m (AM 11 to AM 14) are provided so that the distance between the exposure position (drawing lines SL1 to SL 6) and the observation area Vw1m (Vw 11 to Vw 14) in the X direction is shorter than the length of the exposure area W in the X direction. The plurality of alignment microscopes AM2m (AM 21 to AM 24) are also provided so that the distance between the exposure position (drawing lines SL1 to SL 6) and the observation region Vw2m (Vw 21 to Vw 24) in the X direction is shorter than the length of the exposure region W in the X direction. The number of alignment microscopes AM1m, AM2m provided in the Y direction may be changed according to the number of alignment marks MKm formed in the width direction of the substrate P. The size of the illuminated surface of the substrate P in each of the observation regions Vw1m (Vw 11 to Vw 14) and Vw2m (Vw 21 to Vw 24) is set to a size of about 100 to 500 μm square in accordance with the size of the alignment marks MK1 to MK4 or the alignment accuracy (position measurement accuracy).

As shown in fig. 3, scale portions SDa, SDb having graduations are provided at both ends of the rotary drum DR, the scale portions being formed in a ring shape throughout the entire circumferential direction of the outer circumferential surface of the rotary drum DR. The scale portions SDa, SDb are diffraction gratings each having a concave or convex grating line engraved at a fixed pitch (for example, 20 μm) in the circumferential direction of the outer peripheral surface of the rotary drum DR, and are configured as incremental scales. The scale portions SDa, SDb are rotated integrally with the rotary drum DR about the central axis AXo. The encoders ENja and ENjb (j=1, 2, 3, and 4) serving as the scale reading heads for reading the scale sections SDa and SDb are provided so as to face the scale sections SDa and SDb (see fig. 2 and 3). In fig. 3, the encoders EN4a and EN4b are not shown.

The encoders ENja and ENjb optically detect the rotational angle position of the rotating drum DR. The 4 encoders ENja (EN 1a, EN2a, EN3a, EN4 a) are provided so as to face the scale portion SDa provided at the end of the rotary drum DR in the-Y direction. Similarly, 4 encoders ENjb (EN 1b, EN2b, EN3b, EN4 b) are provided so as to face the scale portion SDb provided at the end portion of the rotary drum DR in the +y direction.

The encoders EN1a and EN1b are disposed on the upstream side (-X direction side) of the center plane Poc in the conveying direction of the substrate P, and are disposed on the installation azimuth line Lx1 (see fig. 2 and 3). The azimuth line Lx1 is set to be a line connecting the projection positions (reading positions) of the measuring beams of the encoders EN1a, EN1b on the scale portions SDa, SDb and the central axis AXo in the XZ plane. The azimuth line Lx1 is set to be a line connecting the observation areas Vw1m (Vw 11 to Vw 14) of the alignment microscopes AM1m (AM 11 to AM 14) and the central axis AXo in the XZ plane. That is, the plurality of alignment microscopes AM1m (AM 11 to AM 14) are also arranged on the installation azimuth line Lx 1.

The encoders EN2a and EN2b are provided on the upstream side (-X direction side) of the center plane Poc in the conveyance direction of the substrate P, and on the downstream side (+x direction side) of the encoders EN1a and EN1b in the conveyance direction of the substrate P. The encoders EN2a and EN2b are arranged on the installation azimuth line Lx2 (see fig. 2 and 3). The azimuth line Lx2 is set to be a line connecting the projection positions (reading positions) of the measuring beams of the encoders EN2a, EN2b on the scale portions SDa, SDb and the central axis AXo in the XZ plane. The installation azimuth line Lx2 overlaps with the irradiation center axes Le1, le3, le5 in the XZ plane at the same angular position.

The encoders EN3a and EN3b are provided on the downstream side (+x direction side) of the center plane Poc in the conveyance direction of the substrate P, and are disposed on the installation azimuth line Lx3 (see fig. 2 and 3). The azimuth line Lx3 is set to be a line connecting the projection positions (reading positions) of the measuring beams of the encoders EN3a and EN3b on the scale portions SDa and SDb and the central axis AXo in the XZ plane. The installation azimuth line Lx3 overlaps with the irradiation center axes Le2, le4, le6 in the XZ plane at the same angular position. Therefore, the set azimuth line Lx2 and the set azimuth line Lx3 are set so that the angle becomes ±θ1 with respect to the center plane Poc in the XZ plane (see fig. 2).

The encoders EN4a and EN4b are disposed on the downstream side (+x direction side) of the encoders EN3a and EN3b in the conveyance direction of the substrate P, and are disposed on the installation azimuth line Lx4 (see fig. 2). The azimuth line Lx4 is set to be a line connecting the projection positions (reading positions) of the measuring beams of the encoders EN4a and EN4b on the scale portions SDa and SDb and the central axis AXo in the XZ plane. The azimuth line Lx4 is set to be a line connecting the observation areas Vw2m (Vw 21 to Vw 24) of the alignment microscopes AM2m (AM 21 to AM 24) with the central axis AXo in the XZ plane. That is, the plurality of alignment microscopes AM2m (AM 21 to AM 24) are also arranged on the installation azimuth line Lx 4. The set azimuth line Lx1 and the set azimuth line Lx4 are set so that the angle thereof in the XZ plane becomes ±θ2 with respect to the center plane Poc (see fig. 2).

The encoders ENja (EN 1a to EN4 a) and ENjb (EN 1b to EN4 b) project measuring light beams toward the scale portions SDa and SDb, and photoelectrically detect the reflected light beams (diffracted light) thereof, thereby outputting detection signals as pulse signals to the control device 16. The rotational position detecting unit 108 (see fig. 9) of the control device 16 counts the detection signals (pulse signals) to measure the rotational angle position and the angular change of the rotating drum DR with a resolution of submicron. The transport speed Vt of the substrate P can be measured based on the angular change of the rotating drum DR. The rotational position detection unit 108 counts detection signals from the encoders ENja (EN 1a to EN4 a) and ENjb (EN 1b to EN4 b) individually.

Specifically, the rotational position detection unit 108 includes a plurality of counter circuits CNja (CN 1a to CN4 a) and CNjb (CN 1b to CN4 b). The counter circuit CN1a counts the detection signal from the encoder EN1a, and the counter circuit CN1b counts the detection signal from the encoder EN1 b. Similarly, the counter circuits CN2a to CN4a, CN2b to CN4b count detection signals from the encoders EN2a to EN4a, EN2b to EN4 b. The counter circuits CNja (CN 1a to CN4 a) and CNjb (CN 1b to CN4 b) reset the count values corresponding to the encoders ENja and ENjb that detected the origin marks ZZ when the encoders ENja (EN 1a to EN4 a) and ENjb (EN 1b to EN4 b) detect the origin marks ZZ (origin patterns) shown in fig. 3 formed at a part of the circumferential direction of the scale portions SDa and SDb.

Any one of the count values of the counter circuits CN1a, CN1b or an average value thereof is used as the rotational angle position of the rotating drum DR on the setting azimuth line Lx1, and any one of the count values of the counter circuits CN2a, CN2b or an average value thereof is used as the rotational angle position of the rotating drum DR on the setting azimuth line Lx 2. Similarly, any one of the count values or the average value of the counter circuits CN3a, CN3b is used as the rotational angle position of the rotating drum DR on the setting azimuth line Lx3, and any one of the count values or the average value of the counter circuits CN4a, CN4b is used as the rotational angle position of the rotating drum DR on the setting azimuth line Lx 4. The counter circuits CN1a and CN1b have the same count value in principle, except that the rotary drum DR rotates eccentrically with respect to the central shaft AXo due to manufacturing errors of the rotary drum DR, or the like. Similarly, the counter circuits CN2a and CN2b have the same count value, and the counter circuits CN3a and CN3b have the same count value, and the counter circuits CN4a and CN4b have the same count value.

As described above, the alignment microscope AM1m (AM 11 to AM 14) and the encoders EN1a and EN1b are disposed on the installation azimuth line Lx1, and the alignment microscope AM2m (AM 21 to AM 24) and the encoders EN4a and EN4b are disposed on the installation azimuth line Lx 4. Therefore, the position of the substrate P on the positional azimuth line Lx1 can be accurately measured based on the position detection of the alignment marks MKm (MK 1 to MK 4) by the image analysis of the mark position detection unit 106 based on the plurality of imaging signals captured by the alignment microscope AM1m (AM 11 to AM 14) and the information of the rotational angle position of the rotating drum DR at the moment captured by the alignment microscope AM1m (based on the count values of the encoders EN1a and EN1 b). Similarly, the position of the substrate P on the position azimuth line Lx4 can be accurately measured based on the position detection of the alignment marks MKm (MK 1 to MK 4) by the image analysis of the mark position detection unit 106 based on the plurality of imaging signals captured by the alignment microscope AM2m (AM 21 to AM 24) and the information of the rotational angle position of the rotating drum DR at the moment captured by the alignment microscope AM2m (based on the count values of the encoders EN4a and EN4 b).

The count values of the detection signals from the encoders EN1a and EN1b, the count values of the detection signals from the encoders EN2a and EN2b, the count values of the detection signals from the encoders EN3a and EN3b, and the count values of the detection signals from the encoders EN4a and EN4b are reset to zero at the moment when the encoders ENja and ENjb detect the origin mark ZZ. Therefore, when the position on the installation azimuth line Lx1 of the substrate P wound around the rotating drum DR is set to the 1 st position when the count value based on the encoders EN1a, EN1b is the 1 st value (for example, 100), the count value based on the encoders EN2a, EN2b is the 1 st value (for example, 100) when the 1 st position on the substrate P is conveyed to the position on the installation azimuth line Lx2 (the position of the drawing lines SL1, SL3, SL 5). Similarly, when the 1 st position on the substrate P is conveyed to the position on the set azimuth line Lx3 (the position of the drawing lines SL2, SL4, SL 6), the count value of the detection signal based on the encoders EN3a, EN3b becomes the 1 st value (for example, 100). Similarly, when the 1 st position on the substrate P is conveyed to the position on the set azimuth line Lx4, the count value based on the detection signals of the encoders EN4a, EN4b becomes the 1 st value (for example, 100).

The substrate P is wound on the inner side of the scale portions SDa and SDb at both ends of the rotating drum DR. In fig. 2, the radius of the outer peripheral surfaces of the scale portions SDa, SDb from the central axis AXo is set smaller than the radius of the outer peripheral surface of the rotary drum DR from the central axis AXo. However, as shown in fig. 3, the outer peripheral surfaces of the scale portions SDa, SDb may be set to be flush with the outer peripheral surface of the substrate P wound around the rotary drum DR. That is, the radius (distance) from the central axis AXo of the outer peripheral surfaces of the scale portions SDa, SDb may be set to be the same as the radius (distance) from the central axis AXo of the outer peripheral surface (irradiated surface) of the substrate P wound around the rotary drum DR. Thus, the encoders ENja (EN 1a to EN4 a) and ENjb (EN 1b to EN4 b) can detect the scale portions SDa and SDb at the same radial positions as the irradiated surface of the substrate P wound around the rotary drum DR. Accordingly, abbe errors caused by the difference between the measurement positions and the processing positions (drawing lines SL1 to SL 6) of the encoders ENja and ENjb in the radial direction of the rotating drum DR can be reduced.

However, since the substrate P as the object to be irradiated has a large difference in thickness of ten to several hundred μm, it is difficult to make the radius of the outer peripheral surfaces of the scale portions SDa, SDb always the same as the radius of the outer peripheral surface of the substrate P wound around the rotary drum DR. Therefore, in the case of the scale portions SDa, SDb shown in fig. 3, the radius of the outer peripheral surface (scale surface) is set so as to match the radius of the outer peripheral surface of the rotary drum DR. Further, the scale portions SDa, SDb may be formed of individual disks, and the disks (scale disks) may be coaxially attached to the long rod Sft of the rotary drum DR. In this case, too, it is preferable that the radius of the outer peripheral surface (scale surface) of the scale disk is matched with the radius of the outer peripheral surface of the rotary drum DR in advance to such an extent that the abbe error is controlled within an allowable value.

From the above, the control device 16 determines the start position of the drawing exposure of the exposure target area W in the longitudinal direction (X direction) of the substrate P based on the position on the substrate P of the alignment marks MKm (MK 1 to MK 4) detected by the alignment microscope AM1m (AM 11 to AM 14) and the count values (any one or average value of the count values of the counter circuits CN1a, CN1 b) based on the encoders EN1a, EN1 b. Since the length of the exposure target area W in the X direction is known in advance, the control device 16 determines the start position of the drawing exposure every time a specific number of alignment marks MKm (MK 1 to MK 4) are detected. When the count value of the encoder EN1a or EN1b is set to the 1 st value (for example, 100) when the exposure start position is determined, the start position of the drawing exposure of the exposure target area W in the longitudinal direction of the substrate P is located on the drawing lines SL1, SL3, SL5 when the count value of the encoder EN2a or EN2b is set to the 1 st value (for example, 100). Therefore, the scanning units U1, U3, U5 can start scanning the spot SP according to the count values of the encoders EN2a, EN2 b. When the count value based on the encoders EN3a, EN3b is the 1 st value (for example, 100), the start position of the drawing exposure of the exposure target area W in the longitudinal direction of the substrate P is located on the drawing lines SL2, SL4, SL 6. Therefore, the scanning units U2, U4, U6 can start scanning of the spot SP according to the count values of the encoders EN3a, EN3 b.

In fig. 2, a substrate P is generally conveyed by tension adjusting rollers RT1 and RT2 while being brought into close contact with a rotating drum DR and simultaneously with the rotation of the rotating drum DR, by applying a predetermined tension to the substrate P in the longitudinal direction. However, the slip of the substrate P with respect to the rotating drum DR may occur due to, for example, the rotation speed Vp of the rotating drum DR being high or the tension applied to the substrate P by the dancer rollers RT1, RT2 becoming too low or too high. When the count values of the encoders EN4a and 4b are equal to the count values (e.g., 150) of the encoders EN1a and EN1b at the moment when the alignment microscope AM1m captures the alignment mark MKmA (a specific alignment mark MKm) while the substrate P is not slid relative to the rotating drum DR, the alignment mark MKmA is detected by the alignment microscope AM2 m.

However, even when the sliding of the substrate P with respect to the rotating drum DR occurs, the count values of the encoders EN4a and EN4b are the same as the count values (e.g., 150) of the encoders EN1a and EN1b at the moment when the alignment microscope AM1m captures the alignment mark MKmA, the alignment mark MKmA is not detected by the alignment microscope AM2 m. In this case, the alignment mark MKmA is detected by the alignment microscope AM2m after the count values of the encoders EN4a, EN4b exceed 150, for example. Therefore, the slip amount with respect to the substrate P can be obtained from the count values of the encoders EN1a and EN1b at the moment when the alignment microscope AM1m photographs the alignment mark MKmA and the count values of the encoders EN4a and EN4b at the moment when the alignment microscope AM2m photographs the alignment mark MKmA. Thus, by additionally providing the alignment microscope AM2m and the encoders EN4a and EN4b, the slip amount of the substrate P can be measured.

Next, an optical configuration of the scanning unit Un (U1 to U6) will be described with reference to fig. 5. Since each of the scanning units Un (U1 to U6) has the same configuration, only the scanning unit (drawing unit) U1 will be described, and the description of the other scanning units Un will be omitted. In fig. 5, the direction parallel to the irradiation center axis Len (Le 1) is referred to as the Zt direction, the direction in which the substrate P passes from the processing apparatus PR2 through the exposure apparatus EX to the processing apparatus PR3 is referred to as the Xt direction, and the direction in which the substrate P passes from the processing apparatus PR2 to the processing apparatus PR3 is referred to as the Yt direction. That is, the three-dimensional coordinates of Xt, yt, and Zt in fig. 5 are three-dimensional coordinates obtained by rotating the three-dimensional coordinates of X, Y, Z in fig. 2 around the Y axis so that the Z axis direction becomes parallel to the irradiation center axis Len (Le 1).

As shown in fig. 5, in the scanning unit U1, a mirror M10, a beam expander BE, a mirror M11, a polarization beam splitter BS1, a mirror M12, a shift optical member (light transmissive parallel plate) SR, a deflection adjusting optical member (prism) DP, a field aperture FA, a mirror M13, a λ/4 wave plate QW, a cylindrical lens CYa, a mirror M14, a polygon mirror PM, an fθ lens FT, a mirror M15, and a cylindrical lens CYb are provided along the advancing direction of the light beam LB1 from the incident position of the light beam LB1 to the irradiated surface (substrate P). Further, in the scanning unit U1, an origin sensor (origin detector) OP1 for detecting the timing at which the scanning unit U1 can start drawing, and an optical lens system G10 and a photodetector DT for detecting reflected light from the irradiated surface (substrate P) via the polarization beam splitter BS1 are provided.

The light beam LB1 incident on the scanning unit U1 is advanced toward the-Zt direction, and is incident on the mirror M10 inclined by 45 ° with respect to the XtYt plane. The light beam LB1 incident on the scanning unit U1 is incident on the mirror M10 so that the axis of the light beam LB1 and the irradiation center axis Le1 are coaxial. The mirror M10 functions as an incident optical member for making the light beam LB1 incident on the scanning unit U1, and reflects the incident light beam LB1 in the-Xt direction toward the mirror M11 separated from the mirror M10 in the-Xt direction along the optical axis AXa set parallel to the Xt axis. Therefore, the optical axis AXa is orthogonal to the irradiation center axis Le1 in a plane parallel to the XtZt plane. The light beam LB1 reflected by the mirror M10 is reflected by the beam expander BE disposed along the optical axis AXa to the mirror M11. The beam expander BE expands the diameter of the transmitted light beam LB 1. The beam expander BE has a condenser lens BE1 and a collimator lens BE2 for collimating the light beam LB1, which is converged by the condenser lens BE1 and diverged.

The mirror M11 is disposed inclined at 45 ° with respect to the YtZt plane, and reflects the incident light beam LB1 (optical axis AXa) in the-Yt direction toward the polarization beam splitter BS 1. The polarization separation surface of the polarization beam splitter BS1 provided so as to be separated from the mirror M11 in the-Yt direction is disposed so as to be inclined by 45 ° with respect to the YtZt plane, and is configured so as to reflect the light flux of the P-polarized light and transmit the light flux of the linearly polarized light (S-polarized light) polarized in the direction orthogonal to the P-polarized light. Since the light beam LB1 incident on the scanning unit U1 is a light beam of P polarized light, the polarization beam splitter BS1 reflects the light beam LB1 from the mirror M11 in the-Xt direction and guides it toward the mirror M12 side.

The mirror M12 is disposed inclined at 45 ° with respect to the XtYt plane, and reflects the incident light beam LB1 in the-Zt direction toward the mirror M13 separated from the mirror M12 in the-Zt direction. The light beam LB1 reflected by the mirror M12 is incident on the mirror M13 along the optical axis AXc parallel to the Zt axis through the shift optical member SR, the deflection adjustment optical member DP, and the field aperture (field stop) FA. The shift optical member SR two-dimensionally adjusts the center position in the cross section of the light beam LB1 in a plane (XtYt plane) orthogonal to the advancing direction (optical axis AXc) of the light beam LB 1. The shift optical member SR is composed of 2 quartz parallel plates SR1, SR2 arranged along the optical axis AXc, the parallel plate SR1 being tiltable around the Xt axis, the parallel plate SR2 being tiltable around the Yt axis. By tilting the parallel flat plates Sr1, sr2 around the Xt axis and the Yt axis, respectively, the position of the center of the light beam LB1 is shifted by a minute amount in two dimensions in the XtYt plane orthogonal to the advancing direction of the light beam LB 1. The parallel flat plates Sr1, sr2 are driven by an actuator (driving unit) not shown under the control of the control device 16. The parallel plate SR2 of the shift optical member SR functions as a mechanical optical beam position adjustment member (1 st adjustment member, 1 st adjustment optical member) that shifts the spot SP of the light beam LB1 projected onto the substrate P in the sub-scanning direction (X direction in fig. 4) by, for example, the size Φ of the spot SP or a range of several times to ten times the pixel size.

The deflection adjusting optical member DP is a member that finely adjusts the inclination of the light beam LB1 passing through the shift optical member SR after being reflected by the mirror M12 with respect to the optical axis AXc. The deflection-adjusting optical member DP is composed of 2 wedge-shaped prisms DP1, DP2 arranged along the optical axis AXc, and each of the prisms DP1, DP2 is provided independently rotatable 360 ° about the optical axis AXc. By adjusting the rotational angle positions of the 2 prisms Dp1, dp2, the alignment between the axis of the light beam LB1 reaching the mirror M13 and the optical axis AXc or the alignment between the axis of the light beam LB1 reaching the irradiated surface of the substrate P and the irradiation center axis Le1 is performed. Further, the beam LB1 deflected by the 2 prisms Dp1, dp2 is laterally shifted in a plane parallel to the cross section of the beam LB1, and the lateral shift can be restored by the shift optical member SR described above. The prisms Dp1 and Dp2 are driven by an actuator (driving unit) not shown under the control of the control device 16.

In this way, the light beam LB1 passing through the shift optical member SR and the deflection adjustment optical member DP passes through the circular opening of the field aperture FA and reaches the mirror M13. The circular opening of the field aperture FA is a diaphragm that cuts off (shields) a peripheral portion (a base portion) of the intensity distribution in the cross section of the light beam LB1 expanded by the beam expander BE. If the circular opening of the field aperture FA is a variable iris diaphragm with an adjustable aperture, the intensity (brightness) of the spot SP can be adjusted.

The mirror M13 is disposed inclined at 45 ° with respect to the XtYt plane, and reflects the incident light beam LB1 toward the mirror M14 in the +xt direction. The beam LB1 reflected by the mirror M13 is incident on the mirror M14 through the λ/4 plate QW and the cylindrical lens CYa. The mirror M14 reflects the incident light beam LB1 toward a polygon mirror (a rotating polygon mirror, a scanning deflecting member) PM. The polygon mirror PM reflects the incident light beam LB1 toward the +xt direction side toward the fθ lens FT having the optical axis AXf parallel to the Xt axis. The polygon mirror PM deflects (reflects) the incident light beam LB1 one-dimensionally in a plane parallel to the XtYt plane in order to scan the spot SP of the light beam LB1 on the irradiated surface of the substrate P. Specifically, the polygon mirror PM includes a rotation shaft AXp extending in the Zt axis direction and a plurality of reflection surfaces RP formed around the rotation shaft AXp (in this embodiment, the number Np of reflection surfaces RP is 8). The reflection angle of the pulsed light beam LB1 applied to the reflection surface RP can be continuously changed by rotating the polygon mirror PM in a specific rotation direction about the rotation axis AXp. By this, the reflection direction of the light beam LB1 is deflected by the 1 reflection surfaces RP, and the spot SP of the light beam LB1 irradiated onto the irradiated surface of the substrate P can be scanned in the main scanning direction (the width direction of the substrate P, the Yt direction).

That is, the spot SP of the light beam LB1 can be scanned along the main scanning direction by 1 reflection surface RP. Therefore, the number of drawing lines SL1 scanned on the irradiated surface of the substrate P by the spot SP by 1 rotation of the polygon mirror PM is 8 as large as the number of reflection surfaces RP at the maximum. The polygon mirror PM is rotated at a fixed speed by a rotation driving source (e.g., a motor or a reduction mechanism) RM under the control of the control device 16. As described above, the effective length (for example, 30 mm) of the drawing line SL1 is set to a length equal to or smaller than the maximum scanning length (for example, 31 mm) at which the spot SP can be scanned by the polygon mirror PM, and at the time of initial setting (in design), the center point (the point at which the irradiation center axis Le1 passes) of the drawing line SL1 is set at the center of the maximum scanning length.

The cylindrical lens CYa converges the incident light beam LB1 on the reflecting surface RP of the polygon mirror PM in a non-scanning direction (Zt direction) orthogonal to the main scanning direction (rotation direction) of the polygon mirror PM. That is, the cylindrical lens CYa converges the light beam LB1 on the reflection surface RP into a long shape (oblong shape) extending in a direction parallel to the XtYt plane. Even when the reflection surface RP is inclined with respect to the Zt direction (the reflection surface RP is inclined with respect to the normal line of the XtYt plane) by the cylindrical lens CYa having the generatrix parallel to the Yt direction and the cylindrical lens CYb described below, the influence thereof can be suppressed. That is, even if the reflection surfaces RP of the polygon mirror PM are slightly inclined from the state parallel to the rotation axis AXp, the irradiation position of the light beam LB1 (drawing line SL 1) irradiated onto the irradiated surface of the substrate P can be suppressed from being shifted in the Xt direction.

An fθ lens (scanning lens system) FT having an optical axis AXf extending in the Xt axis direction projects the light beam LB1 reflected by the polygon mirror PM to a far center system of the mirror M15 so as to be parallel to the optical axis AXf in the XtYt plane. The incident angle θ of the light beam LB1 toward the fθ lens FT varies according to the rotation angle (θ/2) of the polygon mirror PM. The fθ lens FT projects the light beam LB1 via the mirror M15 and the cylindrical lens CYb to an image height position on the illuminated surface of the substrate P in proportion to the incident angle θ. When the focal length is fo and the image height is y, the fθ lens FT is designed so as to satisfy the relationship of y=fo×θ (distortion aberration). Therefore, by the fθ lens FT, the light beam LB1 can be scanned accurately and at a constant speed in the Yt direction (Y direction). When the incident angle θ of the light beam LB1 to the fθ lens FT is 0 degrees, the light beam LB1 incident on the fθ lens FT advances along the optical axis AXf.

The mirror M15 reflects the light beam LB1 from the fθ lens FT toward the substrate P in the-Zt direction through the cylindrical lens CYb. The light beam LB1 projected onto the substrate P is converged on the irradiated surface of the substrate P into a minute spot SP having a diameter of about several μm (for example, 3 μm) by the fθ lens FT and the cylindrical lens CYb having a generatrix parallel to the Yt direction. The spot SP projected onto the irradiated surface of the substrate P is one-dimensionally scanned by the polygon mirror PM on the basis of the drawing line SL1 extending in the Yt direction. The optical axis AXf of the fθ lens FT is on the same plane as the irradiation center axis Le1, and the plane is parallel to the XtZt plane. Therefore, the light beam LB1 traveling on the optical axis AXf is reflected in the-Zt direction by the mirror M15, and is projected onto the substrate P coaxially with the irradiation center axis Le 1. In embodiment 1, at least the fθ lens FT functions as a projection optical system for projecting the light beam LB1 deflected by the polygon mirror PM onto the irradiated surface of the substrate P. At least the reflecting members (the reflecting mirrors M11 to M15) and the polarizing beam splitter BS1 function as optical path deflecting members for bending the optical path of the light beam LB1 from the reflecting mirror M10 to the substrate P. The incidence axis of the light beam LB1 incident on the mirror M10 and the irradiation center axis Le1 can be made substantially coaxial by the optical path deflecting member. In the XtZt plane, the light beam LB1 passing through the scanning unit U1 passes through a substantially U-shaped or コ -shaped optical path, and then advances in the-Zt direction to be projected onto the substrate P.

By scanning the spot SP of the light beams LBn (LB 1 to LB 6) one-dimensionally in the main scanning direction (Y direction) by the respective scanning units Un (U1 to U6) while the substrate P is conveyed in the X direction as described above, the spot SP can be scanned in two dimensions relatively on the irradiated surface of the substrate P.

Further, as an example, when the effective length of the drawing lines SLn (SL 1 to SL 6) is set to 30mm and the light spots SP are irradiated along the drawing lines SLn (SL 1 to SL 6) while overlapping 1/2 of the pulse-shaped light spots SP having an effective size Φ of 3 μm, that is, 1.5 μm, each time the light spots SP are irradiated at 1.5 μm intervals. Therefore, the pulse number of the spot SP irradiated by 1 scan is 20000 (=30 [ mm ]/1.5 [ mu ] m). When the scanning of the spot SP in the sub-scanning direction is also performed at 1.5 μm intervals, the transfer speed (transfer speed) Vt [ mm/sec ] in the sub-scanning direction of the substrate P is 1.5 μm/Tpx [ μsec ] when the time difference between the scanning start (drawing start) time point of 1 time along the drawing line SLn and the next scanning start time point is Tpx [ μsec ]. The time difference Tpx is the time when the polygon mirror PM of the 8 reflection surface RP rotates by 1 surface amount (45 degrees=360 degrees/8). In this case, the period of 1 revolution of the polygon mirror PM must be set so as to be 8×tpx [ μsec ].

On the other hand, the maximum incidence angle (corresponding to the maximum scanning length of the spot SP) at which the light beam LB1 reflected on the 1-reflecting surface RP of the polygon mirror PM is effectively incident on the fθ lens FT is approximately determined by the focal length and the maximum scanning length of the fθ lens FT and the thickness (numerical aperture: NA) in the main scanning direction of the light beam LB1 incident on the 1-reflecting surface RP of the polygon mirror PM. For example, in the case of the polygon mirror PM of the 8 reflection surface RP, the ratio of the rotation angle α contributing to the actual scanning (scanning efficiency) among the rotation angles 45 degrees corresponding to the 1 reflection surface RP is represented by α/45 degrees. In embodiment 1, since the rotation angle α contributing to the actual scanning is 15 degrees, the scanning efficiency becomes 1/3 (=15 degrees/45 degrees), and the maximum incident angle of the fθ lens FT becomes 30 degrees (15 degrees centered on the optical axis AXf). Therefore, the time Ts [ musec ] required for the spot SP to scan at the maximum scanning length (for example, 31 mm) of the drawing line SLn is set to ts=tpx×the scanning efficiency. Since the effective scanning length of the drawing lines SLn (SL 1 to SL 6) in embodiment 1 is set to 30mm, the scanning time Tsp [ μsec ] of 1 scan of the spot SP along the drawing line SLn is tsp=ts× 30 [ mm ]/31 [ mm ]. Therefore, 20000 spots SP (pulse light) must be irradiated during this time Tsp, and therefore the light emission frequency (oscillation frequency) Fa of the light beam LB from the light source device LS (LSa, LSb) becomes Fa 20000/Tsp [ musec ].

The origin sensor OP1 shown in fig. 5 generates an origin signal SZ1 when the rotational position of the reflection surface RP of the polygon mirror PM reaches a specific position at which scanning of the spot SP by the reflection surface RP can start. In other words, the origin sensor OP1 generates the origin signal SZ1 when the angle of the reflection surface RP at which the spot SP is scanned next becomes a specific angle position. Since the polygon mirror PM has 8 reflection surfaces RP, the origin sensor OP1 outputs the origin signal SZ1 8 times during 1 rotation of the polygon mirror PM. The origin signal SZ1 generated by the origin sensor OP1 is transmitted to the control device 16. After the origin sensor OP1 generates the origin signal SZ1 and the delay time Td1 elapses, scanning of the spot SP along the drawing line SL1 is started. That is, the origin signal SZ1 is information indicating the drawing start timing (scanning start timing) of the spot SP by the scanning unit U1.

The origin sensor OP1 has: a beam transmission system opa for emitting a laser beam Bga having a wavelength range that is non-photosensitive with respect to the photosensitive functional layer of the substrate P, onto the reflection surface RP; and a beam receiving system opb for receiving the reflected light Bgb of the laser beam Bga reflected by the reflecting surface RP and generating an origin signal SZ1. Although not shown, the beam transmission system opa includes a light source that emits the laser beam Bga, and an optical member (a mirror, a lens, or the like) that projects the laser beam Bga emitted from the light source onto the reflection surface RP. Although not shown, the light beam receiving system opb includes: a light receiving section including a photoelectric conversion element that receives the received reflected light beam Bgb and converts it into an electrical signal; and an optical member (mirror, lens, or the like) for guiding the reflected light beam Bgb reflected by the reflecting surface RP to the light receiving portion. The beam delivery system opa and the beam receiving system opb are provided at positions where the beam receiving system opb can receive the reflected beam Bgb of the laser beam Bga emitted from the beam delivery system opa when the rotational position of the polygon mirror PM reaches a specific position immediately before the start of scanning of the spot SP by the reflection surface RP. The origin sensors OPn provided in the scanning units U2 to U6 are denoted by OP2 to OP6, and the origin signals SZn generated by the origin sensors OP2 to OP6 are denoted by SZ2 to SZ 6. The control device 16 manages which scanning unit Un scans the spot SP next based on the origin signals SZn (SZ 1 to SZ 6). The delay time Tdn after the origin signals SZ2 to SZ6 are generated and before the scanning of the light spots SP along the drawing lines SL2 to SL6 by the scanning units U2 to U6 is started is sometimes indicated by Td2 to Td 6.

The photodetector DT shown in fig. 5 has a photoelectric conversion element that photoelectrically converts incident light. A predetermined reference pattern is formed on the surface of the rotating drum DR. The portion of the rotating drum DR on which the reference pattern is formed is made of a material having a reflectance (10 to 50%) slightly lower than that of the wavelength region of the light beam LB1, and the other portion of the rotating drum DR on which the reference pattern is not formed is made of a material having a reflectance of 10% or less or a material absorbing light. Therefore, when the spot SP of the light beam LB1 is irradiated from the scanning unit U1 onto the region of the rotating drum DR where the reference pattern is formed in a state where the substrate P is not wound (or a state where the substrate P passes through the transparent portion), the reflected light passes through the cylindrical lens CYb, the mirror M15, the fθ lens FT, the polygon mirror PM, the mirror M14, the cylindrical lens CYa, the λ/4 wave plate QW, the mirror M13, the field aperture FA, the deflection adjusting optical member DP, the shift optical member SR, and the mirror M12, and is incident on the polarization beam splitter BS1. Here, a λ/4 wave plate QW is provided between the polarizing beam splitter BS1 and the substrate P, specifically, between the reflecting mirror M13 and the cylindrical lens CYa. Thus, the beam LB1 irradiated to the substrate P is the beam LB1 converted from P polarized light to circularly polarized light by the λ/4 plate QW, and the reflected light incident to the polarization beam splitter BS1 from the substrate P is converted from circularly polarized light to S polarized light by the λ/4 plate QW. Therefore, the reflected light from the substrate P passes through the polarizing beam splitter BS1 and is incident on the photodetector DT via the optical lens system G10.

At this time, the light spot SP is scanned by the scanning unit U1 while the rotating drum DR is rotated in a state where the pulse-shaped light beam LB1 is continuously incident on the scanning unit U1, whereby the light spot SP is irradiated two-dimensionally on the outer peripheral surface of the rotating drum DR. Therefore, an image signal (photoelectric signal corresponding to the reflection intensity) of the reference pattern formed on the rotating drum DR can be acquired by the photodetector DT.

Specifically, the intensity change of the photoelectric signal outputted from the photodetector DT is obtained as one-dimensional image data in the Yt direction by digitally sampling the clock signal LTC (generated by the light source device LS) in response to the pulse light emission for the light beam LB1 (spot SP). Further, in response to the measurement values of the encoders EN2a and EN2b for measuring the rotational angle position of the rotary drum DR on the drawing line SL1, the image data in one dimension in the Yt direction is arranged in the Xt direction at fixed distances (for example, 1/2 of the size Φ of the spot SP) in the sub-scanning direction, whereby the two-dimensional image information of the surface of the rotary drum DR can be acquired. The control device 16 measures the inclination of the drawing line SL1 of the scanning unit U1 based on the acquired two-dimensional image information of the reference pattern of the rotating drum DR. The inclination of the drawing line SL1 may be a relative inclination between the scanning units Un (U1 to U6) or an inclination (absolute inclination) with respect to the central axis AXo of the rotating drum DR. Needless to say, the inclination of each drawing line SL2 to SL6 may be measured in the same manner. Further, by analyzing the two-dimensional image information of the reference pattern obtained by the photodetector DT, in addition to the inclination error of the drawing lines SL2 to SL6, the position error of the drawing start point or the drawing end point of the drawing lines SL2 to SL6, the joint error of the drawing lines SL2 to SL6, and the like can be confirmed, and the calibration of the scanning units Un (U1 to U6) can be realized.

The plurality of scanning units Un (U1 to U6) are held by a main body frame (not shown) so that each of the plurality of scanning units Un (U1 to U6) can rotate (swivel) around the irradiation center axis Len (Le 1 to Le 6). When the scanning units Un (U1 to U6) rotate around the irradiation center axes Len (Le 1 to Le 6), the drawing lines SLn (SL 1 to SL 6) also rotate around the irradiation center axes Len (Le 1 to Le 6) on the irradiated surface of the substrate P. Accordingly, the drawing lines SLn (SL 1 to SL 6) are inclined with respect to the Y direction. That is, when the scanning units Un (U1 to U6) are rotated around the irradiation center axes Len (Le 1 to Le 6), the relative positional relationship between the light beams LBn (LB 1 to LB 6) passing through the scanning units Un (U1 to U6) and the optical members in the scanning units Un (U1 to U6) is not changed. Therefore, each scanning unit Un (U1 to U6) can scan the spot SP along the rotated drawing lines SLn (SL 1 to SL 6) on the irradiated surface of the substrate P. The rotation of the scanning units Un (U1 to U6) about the irradiation center axes Len (Le 1 to Le 6) is performed by an actuator, not shown, under the control of the control device 16.

Accordingly, the control device 16 rotates the scanning units Un (U1 to U6) around the irradiation center axes Len (Le 1 to Le 6) according to the measured inclination of the drawing lines SLn, whereby the parallel state of the plurality of drawing lines SLn (SL 1 to SL 6) can be maintained. When the substrate P or the exposed region W is strained (deformed) according to the position of the alignment mark MKm detected by the alignment microscopes AM1m and AM2m, the pattern to be drawn is also strained according to the strain. Therefore, when it is determined that the substrate P or the exposure region W is strained (deformed), the control device 16 rotates the scanning units Un (U1 to U6) around the irradiation center axes Len (Le 1 to Le 6), and thereby, the drawing lines SLn are slightly inclined with respect to the Y direction in accordance with the strain (deformation) of the substrate P or the exposure region W. In this case, as will be described later, the present embodiment can control the expansion and contraction of the pattern drawn along each drawing line SLn according to a predetermined magnification (for example, ppm level), or control the displacement of each drawing line SLn in the sub-scanning direction (Xt direction in fig. 5) slightly and individually.

Even if the irradiation center axis Len of the scanning unit Un does not completely coincide with the axis (rotation center axis) of the scanning unit Un about which the scanning unit Un actually rotates, the irradiation center axis Len and the axis (rotation center axis) are coaxial within a specific allowable range. The specific allowable range is set such that a difference between a drawing start point (or a drawing end point) of the actual drawing line SLn when the scanning unit Un rotates at the angle θsm and a drawing start point (or a drawing end point) of the drawing line SLn on design when the scanning unit Un rotates at the specific angle θsm is set to be within a specific distance (for example, a size Φ of the light spot SP) in the main scanning direction of the light spot SP, assuming that the irradiation center axis Len and the rotation center axis are completely coincident. Even if the optical axis of the light beam LBn actually entering the scanner unit Un does not completely coincide with the rotation center axis of the scanner unit Un, the light beam LBn may be coaxial within the specific allowable range.

Fig. 6 is a configuration diagram of the beam switching unit BDU. The beam switching unit BDU includes a plurality of selection optical elements AOMn (AOM 1 to AOM 6), a plurality of condenser lenses CD1 to CD6, a plurality of reflection mirrors M1 to M14, a plurality of unit-side incidence mirrors IM1 to IM6 (IMn), a plurality of collimator lenses CL1 to CL6, and absorbers TR1, TR2. The selection optical elements AOMn (AOM 1 to AOM 6) are transmissive to the light beams LB (LBa, LBb), and are an Acousto-Optic Modulator (AOM) driven by ultrasonic signals. The optical members (optical elements AOM1 to AOM6 for selection, condenser lenses CD1 to CD6, mirrors M1 to M14, unit-side incident mirrors IM1 to IM6, collimator lenses CL1 to CL6, and absorbers TR1, TR 2) are supported by a plate-like support member IUB. The support member IUB supports the optical members above (on the +z direction side) and below (on the (-Z direction side) the plurality of scanning units Un (U1 to U6). Therefore, the support member IUB also has a function of thermally spacing the selection optical elements AOMn (AOM 1 to AOM 6) serving as heat sources from the plurality of scanning units Un (U1 to U6).

The light beam LBa from the light source device LSa is guided to the absorber TR1 by bending its optical path into a meandering shape by the mirrors M1 to M6. In the same manner, the light beam LBb from the light source device LSb is guided to the absorber TR2 by bending its optical path in a zigzag shape by the mirrors M7 to M14. Hereinafter, the selection optical elements AOMn (AOM 1 to AOM 6) are all in the off state (state where no ultrasonic signal is applied).

The light beam LBa (for example, a parallel light beam having a diameter of 1mm or less) from the light source device LSa advances in the +y direction parallel to the Y axis, passes through the condenser lens CD1, and is incident on the mirror M1. The light beam LBa reflected in the-X direction by the mirror M1 passes through the 1 st selection optical element AOM1 disposed at the focal position (beam waist position) of the condenser lens CD1, and is converted into a parallel light beam again by the collimator lens CL1, and reaches the mirror M2. The light beam LBa reflected in the +y direction by the mirror M2 passes through the condenser lens CD2 and is reflected in the +x direction by the mirror M3.

The light beam LBa reflected in the +x direction by the mirror M3 passes through the 2 nd selection optical element AOM2 disposed at the focal position (beam waist position) of the condenser lens CD2, and is converted into a parallel light beam again by the collimator lens CL2, and reaches the mirror M4. The light beam LBa reflected in the +y direction by the mirror M4 passes through the condenser lens CD3 and is reflected in the-X direction by the mirror M5. The light beam LBa reflected in the-X direction by the mirror M5 passes through the 3 rd selective optical element AOM3 disposed at the focal position (beam waist position) of the condenser lens CD3, and is converted into a parallel light beam again by the collimator lens CL3, and reaches the mirror M6. The light beam LBa reflected in the +y direction by the mirror M6 is incident on the absorber TR1. The absorber TR1 is a light collector that absorbs the light beam LBa to suppress leakage of the light beam LBa to the outside.

The light beam LBb (for example, a parallel light beam having a diameter of 1mm or less) from the light source device LSb advances in the +y direction parallel to the Y axis and enters the mirror M13, and the light beam LBb reflected in the +x direction by the mirror M13 is reflected in the +y direction by the mirror M14. The light beam LBb reflected in the +y direction by the mirror M14 passes through the condenser lens CD4 and then is reflected in the +x direction by the mirror M7. The light beam LBb reflected in the +x direction by the mirror M7 passes through the 4 th selective optical element AOM4 disposed at the focal position (beam waist position) of the condenser lens CD4, is converted into a parallel light beam again by the collimator lens CL4, and reaches the mirror M8. The light beam LBb reflected in the +y direction by the mirror M8 passes through the condenser lens CD5 and then is reflected in the-X direction by the mirror M9.

The light beam LBb reflected in the-X direction by the mirror M9 passes through the 5 th selective optical element AOM5 disposed at the focal position (beam waist position) of the condenser lens CD5, is converted into a parallel light beam again by the collimator lens CL5, and reaches the mirror M10. The light beam LBb reflected in the +y direction by the mirror M10 passes through the condenser lens CD6 and then is reflected in the +x direction by the mirror M11. The light beam LBb reflected in the +x direction by the mirror M11 passes through the 6 th selective optical element AOM6 disposed at the focal position (beam waist position) of the condenser lens CD6, is converted into a parallel light beam again by the collimator lens CL6, and reaches the mirror M12. The light beam LBb reflected in the-Y direction by the mirror M12 is incident on the absorber TR2. The absorber TR2 is a light collector that absorbs the light beam LBb in order to suppress leakage of the light beam LBb to the outside.

As described above, the selection optical elements AOM1 to AOM3 are arranged in series along the advancing direction of the light beam LBa so as to sequentially transmit the light beam LBa from the light source device LSa. The selection optical elements AOM1 to AOM3 are arranged so that the condenser lenses CD1 to CD3 and the collimator lenses CL1 to CL3 form the beam waists of the light beams LBa inside the selection optical elements AOM1 to AOM 3. By this, the diameter of the light beam LBa incident on the selection optical elements (acousto-optic modulator) AOM1 to AOM3 is reduced, and the diffraction efficiency and the responsiveness are improved. Similarly, the selection optical elements AOM4 to AOM6 are arranged in series along the advancing direction of the light beam LBb so as to sequentially transmit the light beam LBb from the light source device LSb. The selection optical elements AOM4 to AOM6 are arranged so that the condenser lenses CD4 to CD6 and the collimator lenses CL4 to CL6 form the beam waists of the light beams LBb inside the selection optical elements AOM4 to AOM 6. By this, the diameter of the light beam LBb incident on the selection optical elements (acousto-optic modulator) AOM4 to AOM6 is reduced, and the diffraction efficiency and the responsiveness are improved.

When ultrasonic signals (high-frequency signals) are applied to the selection optical elements AOMn (AOM 1 to AOM 6), 1 st diffraction light obtained by diffracting the incident light beams (0 st order light) LB (LBa, LBb) at a diffraction angle corresponding to the frequency of the high frequency is generated as an outgoing light beam (light beam LBn). In embodiment 1, the light beams LBn emitted as 1 st-order diffracted light from the plurality of selection optical elements AOMn (AOM 1 to AOM 6) are treated as light beams LB1 to LB6, and the selection optical elements AOMn (AOM 1 to AOM 6) serve as a function of deflecting the optical paths of the light beams LB (LBa, LBb) from the light source devices LSa, LSb. However, since the actual acousto-optic modulator generates about 80% of the 0 th order light with the efficiency of generating the 1 st order diffracted light, the intensity of each deflected light beam LBn (LB 1 to LB 6) by each selection optical element AOMn (AOM 1 to AOM 6) is lower than that of the original light beams LB (LBa, LBb). When any of the selection optical elements AOMn (AOM 1 to AOM 6) is in the on state, the 0 th order light that does not diffract and linearly advances remains about 20%, but is eventually absorbed by the absorbers TR1 and TR 2.

As shown in fig. 6, each of the plurality of selection optical elements AOMn (AOM 1 to AOM 6) is provided so as to deflect the deflected 1 st-order diffracted light beams LBn (LB 1 to LB 6) in the-Z direction with respect to the incident light beams LB (LBa, LBb). The light fluxes LBn (LB 1 to LB 6) emitted from the selection optical elements AOMn (AOM 1 to AOM 6) after being deflected are projected onto the unit-side incident mirrors IM1 to IM6 provided at positions apart from the selection optical elements AOMn (AOM 1 to AOM 6) by a predetermined distance, and are reflected in the-Z direction so as to be coaxial with the irradiation center axes Le1 to Le 6. The light fluxes LB1 to LB6 reflected by the unit-side incidence mirrors IM1 to IM6 (hereinafter, also simply referred to as mirrors IM1 to IM 6) are incident on the respective scanning units Un (U1 to U6) along the irradiation center axes Le1 to Le6 through the respective openings TH1 to TH6 formed in the support member IUB.

Further, since the selection optical element AOMn is a diffraction grating that generates periodic variation in the density of the refractive index in a specific direction in the transmission member by ultrasonic waves, when the incident light beams LB (LBa, LBb) are linearly polarized light (P-polarized light or S-polarized light), the polarization direction and the periodic direction of the diffraction grating are set so that the generation efficiency (diffraction efficiency) of 1 st diffraction light becomes the highest. As shown in fig. 6, when the selection optical elements AOMn are provided so as to diffract and deflect the incident light beams LB (LBa, LBs) in the-Z direction, the periodic direction of the diffraction grating generated in the selection optical elements AOMn is also the-Z direction, so that the polarization direction of the light beam LB from the light source device LS (LSa, LSb) is set (adjusted) in a matching manner.

The constitution, function, action, etc. of each of the selection optical elements AOMn (AOM 1 to AOM 6) may be the same as each other. The plurality of selection optical elements AOMn (AOM 1 to AOM 6) are on/off in accordance with a drive signal (high frequency signal) from the control device 16, and generate diffracted light obtained by diffracting the incident light beams LB (LBa, LBb) is performed/not performed. For example, the selection optical element AOM1 transmits the incident light beam LBa from the light source device LSa without diffraction when the light beam LBa is turned off without applying a drive signal (high frequency signal) from the control device 16. Therefore, the light beam LBa transmitted through the selection optical element AOM1 is transmitted through the collimator lens CL1 and is incident on the mirror M2. On the other hand, the selection optical element AOM1 diffracts the incident light beam LBa toward the mirror IM1 when the on state is applied with a drive signal (high frequency signal) from the control device 16. That is, the selection optical element AOM1 is switched in accordance with the driving signal. The mirror IM1 selects the 1 st diffraction light beam LB1 diffracted by the selection optical element AOM1 and reflects it toward the scanning unit U1 side. The light beam LB1 reflected by the selection mirror IM1 is incident on the scanning unit U1 along the irradiation center axis Le1 through the opening TH1 of the support member IUB. Therefore, the mirror IM1 reflects the incident light beam LB1 such that the optical axis of the reflected light beam LB1 is coaxial with the irradiation center axis Le 1. When the selection optical element AOM1 is in the on state, the 0 th order light (about 20% intensity of the incident light beam) of the light beam LB directly transmitted through the selection optical element AOM1 reaches the absorber TR1 through the collimator lenses CL1 to CL3, the condenser lenses CD2 to CD3, the mirrors M2 to M6, and the selection optical elements AOM2 to AOM3 after being transmitted.

Similarly, when the selection optical elements AOM2 and AOM3 are in the off state without the drive signal (high frequency signal) from the control device 16 being applied, the incident light beam LBa (0 th order light) is transmitted to the collimator lenses CL2 and CL3 (the mirrors M4 and M6). On the other hand, when the selection optical elements AOM2 and AOM3 are turned on by the drive signal from the control device 16, the light beams LB2 and LB3, which are 1 st diffraction light of the incident light beam LBa, are directed to the mirrors IM2 and IM3. The mirrors IM2 and IM3 reflect the beams LB2 and LB3 diffracted by the selection optical elements AOM2 and AOM3 toward the scanning units U2 and U3. The light fluxes LB2 and LB3 reflected by the mirrors IM2 and IM3 are incident on the scanning units U2 and U3 coaxially with the irradiation center axes Le2 and Le3 through the openings TH2 and TH3 of the support member IUB.

In this way, the control device 16 switches any one of the selection optical elements AOM1 to AOM3 by turning on/off (high/low) the drive signals (high frequency signals) applied to each of the selection optical elements AOM1 to AOM3, and switches the scanning units U1 to U3, respectively, whether the light beam LBa is directed to the subsequent selection optical element AOM2, AOM3 or the absorber TR1, or whether 1 of the deflected light beams LB1 to LB3 is directed to the corresponding scanning unit.

The selection optical element AOM4 is configured to transmit the light beam LBb from the light source device LSb toward the collimator lens CL4 (the mirror M8) without diffracting the light beam LBb from the light source device LSb when the light beam LBb is turned off without applying a drive signal (high frequency signal) from the control device 16. On the other hand, when the selection optical element AOM4 is turned on by the application of the drive signal from the control device 16, the beam LB4, which is the 1 st diffraction light of the incident beam LBb, is directed to the mirror IM4. The mirror IM4 reflects the light beam LB4 diffracted by the selection optical element AOM4 toward the scanning unit U4. The light beam LB4 reflected by the mirror IM4 is incident on the scanning unit U4 through the opening TH4 of the support member IUB coaxially with the irradiation center axis Le 4.

Similarly, when the selection optical elements AOM5 and AOM6 are in the off state without being supplied with the drive signal (high frequency signal) from the control device 16, the incident light beam LBb is transmitted to the collimator lenses CL5 and CL6 (the mirrors M10 and M12) without being diffracted. On the other hand, when the selection optical elements AOM5 and AOM6 are turned on by the drive signal from the control device 16, the light beams LB5 and LB6, which are 1 st diffraction light of the incident light beam LBb, are directed to the mirrors IM5 and IM6. The mirrors IM5 and IM6 reflect the beams LB5 and LB6 diffracted by the selection optics AOM5 and AOM6 toward the scanning units U5 and U6. The light fluxes LB5 and LB6 reflected by the mirrors IM5 and IM6 are made to pass through the openings TH5 and TH6 of the support member IUB coaxially with the irradiation center axes Le5 and Le6, and are incident on the scanning units U5 and U6.

In this way, the control device 16 switches any one of the selection optical elements AOM4 to AOM6 by turning on/off (high/low) the drive signals (high frequency signals) applied to the respective selection optical elements AOM4 to AOM6, and switches the 1 of the light beams LBb to the corresponding scanning units U4 to U6 toward the subsequent selection optical element AOM5, AOM6 or absorber TR2 or the deflected light beams LB4 to LB 6.

As described above, the beam switching unit BDU includes the plurality of selection optical elements AOMn (AOM 1 to AOM 3) arranged in series along the advancing direction of the light beam LBa from the light source device LSa, and can switch the optical path of the light beam LBa to select 1 scanning unit Un (U1 to U3) on which the light beam LBn (LB 1 to LB 3) is incident. Therefore, the light beams LBn (LB 1 to LB 3) which are 1 st diffraction light of the light beam LBa from the light source device LSa are sequentially incident on the respective 3 scanning units Un (U1 to U3). For example, the control device 16 may set the selection optical element AOM1 of the plurality of selection optical elements AOM1 to AOM3 to the on state when the light beam LB1 is to be made to enter the scanning unit U1, and may set the selection optical element AOM3 to the on state when the light beam LB3 is to be made to enter the scanning unit U3.

Similarly, the beam switching unit BDU includes a plurality of selection optical elements AOMn (AOM 4 to AOM 6) arranged in series along the advancing direction of the light beam LBb from the light source device LSb, and can switch the optical path of the light beam LBb to select 1 scanning unit Un (U4 to U6) on which the light beam LBn (LB 4 to LB 6) is incident. Therefore, the light beams LBn (LB 4 to LB 6), which are 1 st diffraction light of the light beam LBb from the light source device LSb, are sequentially incident on the respective 3 scanning units Un (U4 to U6). For example, when the light beam LB4 is to be made incident on the scanning unit U4, the control device 16 may set the selection optical element AOM4 among the plurality of selection optical elements AOM4 to AOM6 to the on state, and when the light beam LB6 is to be made incident on the scanning unit U6, the selection optical element AOM6 may be set to the on state.

The plurality of selection optical elements AOMn (AOM 1 to AOM 6) are provided corresponding to the plurality of scanning units Un (U1 to U6), and switch whether or not the light beam LBn is made to enter the corresponding scanning unit Un. In embodiment 1, the selection optical elements AOM1 to AOM3 are referred to as 1 st optical element modules, and the selection optical elements AOM4 to AOM6 are referred to as 2 nd optical element modules. The scanning units U1 to U3 corresponding to the selection optical elements AOM1 to AOM3 of the 1 st optical element module are referred to as 1 st scanning module, and the scanning units U4 to U6 corresponding to the selection optical elements AOM4 to AOM6 of the 2 nd optical element module are referred to as 2 nd scanning module. Therefore, the spot SP is scanned in parallel by any one of the scanning units Un of the 1 st scanning module and any one of the scanning units Un of the 2 nd scanning module.

As described above, in embodiment 1, the rotation angle α of the polygon mirror PM of the scanning unit Un contributing to actual scanning is set to 15 degrees, and thus the scanning efficiency becomes 1/3. Therefore, for example, while 1 scanning unit Un rotates by an angle (45 degrees) corresponding to 1 reflection surface RP, the angle at which the spot SP can be scanned becomes 15 degrees, and in the other angle range (30 degrees), the spot SP cannot be scanned, and the light flux LBn incident on the polygon mirror PM is wasted. Therefore, during a period when the rotation angle of the polygon mirror PM of one 1 scanning unit Un is an angle that does not contribute to actual scanning, the light beam LBn is made incident on the other scanning units Un, and the polygon mirror PM of the other scanning units Un can be used to scan the light spot SP. Since the scanning efficiency of the polygon mirror PM is 1/3, the spot SP can be scanned by distributing the light beam LBn to the other 2 scanning units Un in the period from when one 1 scanning unit Un scans the spot SP to when the next scanning is performed. Therefore, in embodiment 1, the plurality of scanning units Un (U1 to U6) are divided into 2 groups (scanning modules), the 3 scanning units U1 to U3 are 1 st scanning module, and the 3 scanning units U4 to U6 are 2 nd scanning module.

Thus, for example, while the polygon mirror PM of the scanning unit U1 is rotated 45 degrees (corresponding to the 1 reflection surface RP), the light fluxes LBn (LB 1 to LB 3) are sequentially incident on any one of the 3 scanning units U1 to U3. Accordingly, each of the scanning units U1 to U3 can sequentially scan the light spots SP without wasting the light beam LBa from the light source device LSa. Similarly, while the polygon mirror PM of the scanning unit U4 is rotated 45 degrees (corresponding to the 1 reflection surface RP), the light beams LBn (LB 4 to LB 6) can be sequentially incident on any one of the 3 scanning units U4 to U6. Therefore, the scanning units U4 to U6 can sequentially scan the light spots SP without wasting the light beam LBb from the light source device LSb. Further, the polygon mirror PM is rotated by an angle (45 degrees) corresponding to 1 reflection surface RP during a period from when each scanning unit Un starts scanning the spot SP to when the next scanning is started.

In embodiment 1, since the respective 3 scanning units Un (U1 to U3, U4 to U6) of each scanning module scan the light spot SP in a specific order, the control device 16 sequentially switches on the 3 selection optical elements AOMn (AOM 1 to AOM3, AOM4 to AOM 6) of each optical element module in a specific order and switches on the scanning units Un (U1 to U3, U4 to U6) on which the light beams LBn (LB 1 to LB3, LB4 to LB 6) are incident. For example, when the order of scanning the spot SP by the 3 scanning units U1 to U3, U4 to U6 of each scanning module is U1→u2→u3, U4→u5→u6, the control device 16 switches the 3 selection optical elements AOMn (AOM 1 to AOM3, AOM4 to AOM 6) of each optical element module to on in the order of AOM1→aom2→aom3, AOM4→aom5→aom6, and switches the scanning unit Un on which the light beam LBn is incident in the order of U1→u2→u3, U4→u5→u6.

In order to sequentially scan the light spot SP by the 3 scanning units Un (U1 to U3, U4 to U6) of each scanning module while the polygon mirror PM rotates by an angle (45 degrees) corresponding to the 1 reflection surface RP, each polygon mirror PM of the 3 scanning units Un (U1 to U3, U4 to U6) of each scanning module must rotate as follows. This condition means that the polygon mirrors PM of the 3 scanning units Un (U1 to U3, U4 to U6) of each scanning module must be synchronously controlled so as to have the same rotational speed Vp, and that the rotational angular position of each polygon mirror PM (the angular position of each reflection surface RP) is synchronously controlled so as to have a specific phase relationship. The rotation of the polygon mirror PM at the same rotation speed Vp of the 3 scanning units Un of each scanning module is referred to as synchronous rotation.

Fig. 7 is a diagram showing the configuration of a light source device (pulse light source device, pulse laser device) LSa (LSb). The light source device LSa (LSb) as a fiber laser device includes a pulse light generating unit 20 and a control circuit 22. The pulse light generating section 20 includes DFB semiconductor laser elements 30 and 32, a polarization beam splitter 34, a photocell (intensity modulation section) 36 as a light modulator for drawing, a driving circuit 36a of the photocell 36, a polarization beam splitter 38, an absorber 40, an excitation light source 42, a combiner 44, a fiber optical amplifier 46, wavelength conversion optical elements 48 and 50, and a plurality of lens elements GL. The control circuit 22 includes a signal generating section 22a for generating a clock signal LTC and a pixel shift pulse BSC. In order to distinguish the pixel shift pulse BSC outputted from the signal generating unit 22a of the light source device LSa from the pixel shift pulse BSC outputted from the signal generating unit 22a of the light source device LSb, the pixel shift pulse BSC from the light source device LSa may be denoted by BSCa, and the pixel shift pulse BSC from the light source device LSb may be denoted by BSCb.

The DFB semiconductor laser device (1 st solid-state laser device) 30 generates a sharp (sharp) or pointed pulse-like seed light (pulse beam, light beam) S1 at an oscillation frequency Fa (e.g., 400 MHz) as a specific frequency in cooperation with a pulse wave cutting system such as a Q-switch (not shown), and the DFB semiconductor laser device (2 nd solid-state laser device) 32 generates a slow (time-wide) pulse-like seed light (pulse light beam, light beam) S2 at an oscillation frequency Fa (e.g., 400 MHz) as a specific frequency. The light emission timing of the seed light S1 generated by the DFB semiconductor laser device 30 is synchronized with the light emission timing of the seed light S2 generated by the DFB semiconductor laser device 32. The seed light S1 and S2 have substantially the same energy per 1 pulse, but have different polarization states, and the peak intensity is high in the seed light S1. The seed light S1 and the seed light S2 are linearly polarized light, and the polarization directions thereof are orthogonal to each other. In embodiment 1, the polarization state of the seed light S1 generated by the DFB semiconductor laser device 30 is S-polarized, and the polarization state of the seed light S2 generated by the DFB semiconductor laser device 32 is P-polarized. The light S1, S2 is light in the infrared wavelength region.

The control circuit 22 controls the DFB semiconductor laser devices 30 and 32 so as to emit the seed light S1 and S2 in response to the clock pulse of the clock signal LTC sent from the signal generating unit 22 a. Accordingly, the DFB semiconductor laser devices 30 and 32 emit the seed lights S1 and S2 at the specific frequency (oscillation frequency Fa) Fa in response to each clock pulse (oscillation frequency Fa) of the clock signal LTC. The control circuit 22 is controlled by the control device 16. The period (=1/Fa) of the clock pulse of the clock signal LTC is referred to as a reference period Ta. Seed light S1, S2 generated by the DFB semiconductor laser devices 30, 32 is directed to the polarizing beam splitter 34.

The clock signal LTC serving as the reference clock signal is a reference for the pixel shift pulses BSC (BSCa, BSCb) supplied to each counter unit for designating the addresses in the column direction in the memory circuit of the dot matrix pattern data, and will be described in detail below. The signal generating unit 22a receives, from the control device 16, the whole magnification correction information TMg for performing whole magnification correction of the drawing line SLn on the irradiated surface of the substrate P and the partial magnification correction information CMgn (CMg 1 to CMg 6) for performing partial magnification correction of the drawing line SLn. Thus, the length of the pattern drawn by the drawing line SLn on the irradiated surface of the substrate P (pattern drawing length) can be finely adjusted, which will be described in detail below. The stretching and contraction (fine adjustment of the scanning length) of the pattern drawing length can be performed within a range of about ±1000ppm, for example, within a maximum scanning length (for example, 31 mm) of the drawing line SLn. Further, in the embodiment 1, the overall magnification correction is simply described, and by uniformly fine-adjusting the projection interval (that is, the oscillation frequency of the spot) of the spot SP projected in the main scanning direction while the number of spots included in 1 pixel (1 bit) on the drawing data is kept constant, the drawing magnification in the scanning direction of the entire drawing line SLn is corrected to be uniform. Further, in the case of the partial magnification correction in embodiment 1, the partial magnification correction is simply described by taking 1 pixel (1 bit) of each of the discrete plurality of correction points set on the 1 drawing line as an object, and by slightly increasing or decreasing the interval in the main scanning direction of the light spot SP among the pixels of the correction point from the standard interval (for example, 1/2 of the size Φ of the light spot SP), the size of the pixels drawn on the substrate is slightly smaller than that in the main scanning direction.

The polarization beam splitter 34 transmits the S-polarized light and reflects the P-polarized light, and guides the seed light S1 generated by the DFB semiconductor laser device 30 and the seed light S2 generated by the DFB semiconductor laser device 32 to the photoelectric device 36. Specifically, the polarization beam splitter 34 transmits the seed light S1 of the S-polarized light generated by the DFB semiconductor laser device 30, and guides the seed light S1 to the photoelectric device 36. The polarization beam splitter 34 reflects the seed light S2 of the P-polarized light generated by the DFB semiconductor laser device 32 to guide the seed light S2 to the photoelectric device 36. The DFB semiconductor laser elements 30, 32 and the polarization beam splitter 34 constitute a pulse light source section 35 for generating the seed light S1, S2.

The Electro-optical element (intensity Modulator) 36 is permeable to the seed light S1, S2, and an Electro-optical Modulator (EOM) is used, for example. The photo-device 36 responds to the high/low state of the data SBa (SBb) of the drawing bit string, and the polarized light states of the seed lights S1, S2 are switched by the driving circuit 36a. The drawing bit string data SBa is generated based on pattern data (bit pattern) corresponding to the pattern to be exposed of each of the scanning units U1 to U3, and the drawing bit string data SBb is generated based on pattern data (bit pattern) corresponding to the pattern to be exposed of each of the scanning units U4 to U6. Therefore, the drawing bit string data SBa is input to the driving circuit 36a of the light source device LSa, and the drawing bit string data SBb is input to the driving circuit 36a of the light source device LSa. Since the seed lights S1 and S2 from the DFB semiconductor laser device 30 and the DFB semiconductor laser device 32 have a longer wavelength region of 800nm or more, the photoelectric device 36 may have a polarization state switching response of GHz.

The pattern data (drawing data) is provided for each scanning unit Un, and the pattern drawn by each scanning unit Un is divided by pixels of a size Pxy set according to the size phi of the light spot SP, and each of the plurality of pixels is represented by logic information (pixel data) corresponding to the pattern. That is, the pattern data is a bitmap data composed of logical information of a plurality of pixels which are two-dimensionally decomposed so that a direction along the main scanning direction (Y direction) of the spot SP is a column direction and a direction along the sub-conveying direction (X direction) of the substrate P is a row direction. The logical information of the pixel is 1-bit data of "0" or "1". The logical information of "0" means that the intensity of the spot SP irradiated onto the substrate P is set to a low level (not depicted), and the logical information of "1" means that the intensity of the spot SP irradiated onto the substrate P is set to a high level (depicted). The pixel size Pxy is defined as Py in the main scanning direction (Y direction) and the sub scanning direction (X direction) is defined as Px.

The logical information of 1-line number of pixels of the pattern data corresponds to 1 drawing line SLn (SL 1 to SL 6). Therefore, the number of pixels of 1 line may be determined according to the size Pxy of the pixels on the irradiated surface of the substrate P and the length of the drawing line SLn. The 1-pixel size Pxy is set to be the same as or greater than the size phi of the spot SP, and for example, when the effective size phi of the spot SP is 3 μm, the 1-pixel size Pxy is set to be about 3 μm square or greater. The intensity of the light spot SP projected onto the substrate P along 1 drawing line SLn (SL 1 to SL 6) is modulated based on the logical information of the pixels of 1 line. The logical information of the 1-column pixel is called serial data DLn. That is, the pattern data is dot matrix pattern data in which the serial data DLn are arranged in the column direction. The serial data DLn of the pattern data of the scanning unit U1 is denoted by DL1, and similarly, the serial data DLn of the pattern data of the scanning units U2 to U6 is denoted by DL2 to DL 6.

Further, since the scanning operation of the light spots SP is repeated sequentially in a specific order in the 3 scanning units U1 to U3 (U4 to U6) of the scanning module, the serial data DL1 to DL3 (DL 4 to DL 6) of the pattern data of the 3 scanning units U1 to U3 (U4 to U6) of the scanning module are outputted to the driving circuit 36a of the light source device LSa (LSb) in a specific order. The serial data DL1 to DL3 sequentially output to the driving circuit 36a of the light source device LSa are referred to as drawing bit string data SBa, and the serial data DL4 to DL6 sequentially output to the driving circuit 36a of the light source device LSa are referred to as drawing bit string data SBb.

For example, when the order of the scanning units Un for scanning the light spot SP in the 1 st scanning module is U1→u2→u3, first, 1-line serial data DL1 is output to the driving circuit 36a of the light source device LSa, then 1-line serial data DL2 is output to the driving circuit 36a of the light source device LSa, and 1-line serial data DL1 to DL3 constituting the drawing bit string data SBa are output to the driving circuit 36a of the light source device LSa in the order of DL1→dl2→dl 3. Thereafter, the serial data DL1 to DL3 of the next column are outputted as the drawing bit string data SBa to the driving circuit 36a of the light source device LSa in the order of DL1→dl2→dl 3. Similarly, when the order of the scanning units Un for scanning the light spot SP in the 2 nd scanning module is U4, U5, U6, first, 1-line serial data DL4 is output to the driving circuit 36a of the light source device LSb, then 1-line serial data DL5 is output to the driving circuit 36a of the light source device LSb, and 1-line serial data DL4 to DL6 constituting the drawing bit string data SBb are output to the driving circuit 36a of the light source device LSb in the order of DL4, DL5, DL 6. Thereafter, the serial data DL4 to DL6 of the next column are outputted as the drawing bit string data SBb to the driving circuit 36a of the light source device LSb in the order of DL4→dl5→dl 6. The specific configuration of the driving circuit 36a for outputting the drawing bit string data SBa (SBb) to the light source device LSa (LSb) will be described in detail below.

When the logic information of 1 pixel of the drawing bit string data SBa (SBb) inputted to the driving circuit 36a is in the low ("0") state, the photocell 36 directly directs the polarized light of the variable light S1, S2 to the polarization beam splitter 38 without changing the polarized light state. On the other hand, when the logic information of 1 pixel of the drawing bit string data SBa (SBb) inputted to the driving circuit 36a is in the high ("1") state, the photoelectric element 36 changes the polarization states of the incident seed lights S1, S2, that is, changes the polarization direction by 90 degrees, and guides the changed polarized light to the polarization beam splitter 38. By driving the photocell 36 based on the drawing bit string data SBa (SBb) by the driving circuit 36a in this way, when the logical information of the pixel of the drawing bit string data SBa (SBb) is in a high state ("1"), the photocell 36 converts the seed light S1 of S polarized light into the seed light S1 of P polarized light and converts the seed light S2 of P polarized light into the seed light S2 of S polarized light.

The polarizing beam splitter 38 transmits the P-polarized light and guides the P-polarized light to the combiner 44 through the lens element GL, and reflects the S-polarized light and guides the S-polarized light to the absorber 40. The light (seed light) transmitted through the polarizing beam splitter 38 is denoted by a light beam Lse. The oscillation frequency of the pulse-like light beam Lse becomes Fa. The excitation light source 42 generates excitation light, which is directed to the combiner 44 through the optical fiber 42 a. The combiner 44 combines the light beam Lse irradiated from the polarizing beam splitter 38 with the excitation light, and outputs the combined light beam to the optical fiber amplifier 46. The fiber optic amplifier 46 is doped with a lasing medium excited by the excitation light. Accordingly, in the optical fiber amplifier 46 for transmitting the synthesized light beam Lse and the excitation light, the laser medium is excited by the excitation light, whereby the light beam Lse as the seed light is amplified. As a laser medium doped in the optical fiber amplifier 46, rare earth elements such as erbium (Er), ytterbium (Yb), and thulium (Tm) are used. The amplified light beam Lse is radiated from the output end 46a of the fiber optic amplifier 46 with a specific divergence angle, converged or collimated by the lens element GL, and incident on the wavelength conversion optical element 48.

The wavelength conversion optical element (1 st wavelength conversion optical element) 48 converts the incident light beam Lse (wavelength λ) into a 2 nd harmonic of 1/2 of the wavelength λ by the 2 nd harmonic generation (Second Harmonic Generation: SHG). As the wavelength conversion optical element 48, a PPLN (Periodically Poled LiNbO 3) crystal that is a quasi-phase matching (Quasi Phase Matching: QPM) crystal is preferably used. Further, a crystal of PPLT (Periodically Poled LiTaO 3) or the like may also be used.

The wavelength conversion optical element (2 nd wavelength conversion optical element) 50 generates (Sum Frequency Generation: SFG) the sum frequency of the 2 nd harmonic (wavelength λ/2) converted by the wavelength conversion optical element 48 and the seed light (wavelength λ) remaining without being converted by the wavelength conversion optical element 48, thereby generating the 3 rd harmonic having a wavelength of 1/3 of λ. The 3 rd harmonic is ultraviolet light (beam LB) having a peak wavelength in a wavelength band of 370mm or less (for example, 355 nm).

As shown in fig. 8, when the logical information of 1 pixel of the drawing bit string data SBa (SBb) applied to the driving circuit 36a is low ("0"), the photoelectric element (intensity modulation unit) 36 directly guides the incident seed light S1, S2 to the polarization beam splitter 38 without changing the polarization state of the seed light. Therefore, the light beam Lse transmitted through the polarization beam splitter 38 becomes the seed light S2. Therefore, the LBa (LBb) of the P-polarized light finally output from the light source device LSa (LSb) has the same oscillation distribution (temporal characteristics) as the seed light S2 from the DFB semiconductor laser element 32. That is, in this case, the light beam LBa (LBb) has a characteristic of passivation that the peak intensity of the pulse is low and wide in time. Since the optical fiber amplifier 46 has low amplification efficiency for the seed light S2 having such a low peak intensity, the light beam LBa (LBb) emitted from the light source device LSa (LSb) is light having energy which is not amplified to be required for exposure. Therefore, from the viewpoint of exposure, the same result as that of the light source device LSa (LSb) that does not emit the light beam LBa (LBb) is obtained. That is, the intensity of the spot SP irradiated to the substrate P becomes low. However, during the period in which the exposure of the pattern is not performed (non-exposure period), the light beam LBa (LBb) from the ultraviolet ray region of the seed light S2 is continuously irradiated even though it has a small intensity. Therefore, when the drawing lines SL1 to SL6 are maintained in the same position on the substrate P for a long period of time (for example, when the substrate P is stopped due to a failure of the conveying system), it is preferable to provide a movable shutter to close the emission window (not shown) of the light beam LBa (LBb) of the light source device LSa (LSb).

On the other hand, as shown in fig. 8, when the logical information of 1 pixel of the drawing bit string data SBa (SBb) applied to the driving circuit 36a is high ("1"), the photoelectric element (intensity modulation section) 36 changes the polarization states of the incident seed lights S1, S2 and guides them to the polarization beam splitter 38. Therefore, the light beam Lse transmitted through the polarization beam splitter 38 becomes the seed light S1. Therefore, the light beam LBa (LBb) emitted from the light source device LSa (LSb) is generated by the seed light S1 from the DFB semiconductor laser device 30. Since the seed light S1 from the DFB semiconductor laser device 30 has a strong peak intensity, the seed light S1 is efficiently amplified by the fiber optical amplifier 46, and the beam LBa (LBb) of the P-polarized light outputted from the light source device LSa (LSb) has energy required for exposing the substrate P. That is, the intensity of the spot SP irradiated to the substrate P becomes high.

As described above, since the photocell 36 serving as the drawing light modulator is provided in the light source device LSa (LSb), the intensity of the light spot SP scanned by the 3 scanning units U1 to U3 (U4 to U6) of the scanning module can be modulated according to the pattern to be drawn by controlling 1 photocell (intensity modulating unit) 36. Therefore, the light beam LBa (LBb) emitted from the light source device LSa (LSb) becomes an intensity-modulated drawing light beam.

In the configuration of fig. 7, it is also conceivable to omit the DFB semiconductor laser device 32 and the polarization beam splitter 34, and to introduce only the seed light S1 from the DFB semiconductor laser device 30 to the optical fiber amplifier 46 in an explosive wave shape by switching the polarization states of the photocell 36 based on pattern data (drawing bit string data SBa, SBb, or serial data DLn). However, with this configuration, the incidence periodicity of the seed light S1 to the optical fiber amplifier 46 is greatly disturbed according to the pattern to be drawn. That is, if the state in which the seed light S1 from the DFB semiconductor laser device 30 is not incident on the optical fiber amplifier 46 continues and then the seed light S1 is incident on the optical fiber amplifier 46, the following problem occurs: the seed light S1 immediately after incidence is amplified at a larger amplification factor than usual, and a light beam (giant pulse) having a larger intensity than a predetermined value is generated from the fiber optical amplifier 46 by a few pulses. Therefore, in embodiment 1, as a preferable mode, the seed light S2 (broad pulse light having a low peak intensity) from the DFB semiconductor laser device 32 is made to enter the optical fiber amplifier 46 while the seed light S1 is not made to enter the optical fiber amplifier 46, thereby solving the above-described problem.

The photoelectric element 36 is switched, but the DFB semiconductor laser elements 30, 32 may be driven based on pattern data (drawing bit string data SBa, SBb, or serial data DLn). In this case, the DFB semiconductor laser devices 30 and 32 function as a drawing light modulator (intensity modulator). Specifically, the control circuit 22 controls the DFB semiconductor laser devices 30 and 32 based on the drawing bit string data SBa (DL 1 to DL 3) and SBb (DL 4 to DL 6) to selectively (selectively) generate the seed lights S1 and S2 oscillating in a pulse shape at the specific frequency Fa. In this case, one of the seed lights S1, S2 selectively pulsed from either of the DFB semiconductor laser devices 30, 32 is directly incident on the combiner 44 without the polarizing beam splitters 34, 38, the photo-electric element 36, and the absorber 40. At this time, the control circuit 22 controls the driving of each DFB semiconductor laser device 30, 32 so that the seed light S1 from the DFB semiconductor laser device 30 and the seed light S2 from the DFB semiconductor laser device 32 are not incident on the fiber optical amplifier 46 at the same time. That is, when the spot SP of each light flux LBn is irradiated onto the substrate P, the DFB semiconductor laser device 30 is controlled so that only the seed light S1 is incident on the fiber optical amplifier 46. When the spot SP of each of the light beams LBn is not irradiated onto the substrate P (the intensity of the spot SP is extremely low), the DFB semiconductor laser device 32 is controlled so that only the seed light S2 is incident on the fiber optical amplifier 46. In this way, whether or not to irradiate the substrate P with the light beam LBn is determined based on the logical information (high/low) of the pixel. In this case, the polarized light states of the seed lights S1 and S2 may be P polarized light.

Here, the light source device LSa (LSb) emits the light beam LBa (LBb) such that N light spots SP are projected in the main scanning direction for 1 pixel of the size Pxy on the irradiated surface of the substrate P in scanning of the light spots SP (n=2 in embodiment 1). The light beam LBa (LBb) emitted from the light source device LSa (LSb) is generated in response to the clock pulse of the clock signal LTC generated by the signal generating unit 22 a. Therefore, in order to project N (N may be an integer of 2 or more) light spots SP for 1 pixel of the size Pxy, when Vs is set as the relative scanning speed of the light spots SP with respect to the substrate P in the main scanning direction, the signal generating unit 22a must generate the clock pulse of the clock signal LTC at the reference period Ta (=1/Fa) determined by Pxy/(n×vs) or Py/(n×vs). For example, if the effective drawing line SLn is 30mm long and the 1-pass scanning time Tsp is about 50 μsec, the scanning speed Vs of the spot SP becomes about 600m/sec. When the pixel size Pxy (Px and Py) is 3 μm which is the same as the effective size of the spot SP and N is 2, the reference period ta=3 μm/(2×600 m/sec) =0.0025 μsec is set, and the frequency Fa (=1/Ta) is 400MHz.

The correction position information (set value) Nv of the partial magnification correction information CMgn (CMg 1 to CMg 6) is arbitrarily changeable and is appropriately set according to the magnification of the drawing line SLn. For example, the correction position information Nv may be set so that 1 correction pixel is located on the drawing line SLn. The drawing line SL can be extended and contracted by the whole magnification correction information TMg, but the partial magnification correction can be performed with finer and finer magnification correction. For example, when the oscillation frequency Fa is 400MHz and the initial value of the scanning length (drawing range) of the drawing line SLn is 30mm, the oscillation frequency Fa must be increased or decreased by about 0.2MHz (ratio 500 ppm) when the scanning length of the drawing line SLn is extended or contracted by 15 μm (ratio 500 ppm) by the whole magnification correction information TMg, and adjustment thereof is difficult. Even if the adjustment is possible, the oscillation frequency Fa is switched to the adjusted oscillation frequency Fa with a fixed delay (time constant), and thus a desired magnification cannot be obtained therebetween. Further, when the correction ratio of the drawing magnification is set to 500ppm or less, for example, several ppm to several tens ppm, the local magnification correction method of increasing or decreasing the number of light spots in the discrete correction pixels can easily perform the correction with higher resolution than the entire magnification correction method of changing the oscillation frequency Fa of the light source device LSa (LSb). Of course, if both the whole magnification correction method and the partial magnification correction method are used in combination, the advantage is obtained that the correction ratio corresponding to a large drawing magnification can be obtained and the correction of high resolution can be realized.

Fig. 9 is a block diagram showing an electrical configuration of the exposure apparatus EX. The control device 16 of the exposure apparatus EX includes a polygon mirror drive control unit 100, a selection element drive control unit 102, a beam control unit 104, a mark position detection unit 106, and a rotational position detection unit 108. The origin signals SZn (SZ 1 to SZ 6) output from the origin sensors OPn (OP 1 to OP 6) of the respective scanning units Un (U1 to U6) are input to the polygon mirror drive control unit 100 and the selection element drive control unit 102. In the example shown in fig. 9, the light beam LBa (LBb) from the light source device LSa (LSb) is diffracted by the selection optical element AOM2 (AOM 5) to make the 1 st diffraction light beam LB2 (LB 5) enter the scanning unit U2 (U5).

The polygon mirror drive control unit 100 drives and controls rotation of the polygon mirror PM of each scanning unit Un (U1 to U6). The polygon mirror drive control unit 100 includes a rotation drive source (motor, speed reducer, or the like) RM for driving the polygon mirror PM of each of the scanning units Un (U1 to U6), and drives and controls the rotation of the polygon mirror PM by driving and controlling the rotation of the motor. The polygon mirror drive control unit 100 synchronously rotates the polygon mirrors PM of the 3 scanning units Un (U1 to U3, U4 to U6) of each scanning module so that the rotational angle positions of the polygon mirrors PM of the 3 scanning units Un (U1 to U3, U4 to U6) of each scanning module have a specific phase relationship. That is, the polygon mirror drive control unit 100 controls the rotation of the polygon mirror PM of the plurality of scanning units Un (U1 to U6) such that the rotational speeds (rotations) Vp of the polygon mirrors PM of the 3 scanning units Un (U1 to U3, U4 to U6) of each scanning module are identical to each other and the phases of the rotational angle positions are shifted by a fixed angle amount each time. The rotational speeds Vp of the polygon mirrors PM of the scanning units Un (U1 to U6) are all the same.

In embodiment 1, since the rotation angle α of the polygon mirror PM contributing to the actual scanning is set to 15 degrees as described above, the scanning efficiency of the polygon mirror PM having 8 octagonal reflection surfaces RP is 1/3. In the 1 st scanning module, scanning of the spot SP by the 3 scanning units Un is performed in the order of u1→u2→u3. Accordingly, the polygon mirror PM of each of the scanning units U1 to U3 is synchronously controlled by the polygon mirror drive control unit 100 so that the phases of the rotational angle positions of the polygon mirrors PM of each of the 3 scanning units U1 to U3 are rotated at the same speed in a state of being shifted by 15 degrees each time in this order. In the 2 nd scanning module, scanning of the spot SP by the 3 scanning units Un is performed in the order of u4→u5→u6. Therefore, the polygon mirror PM of each of the scanning units U4 to U6 is synchronously controlled by the polygon mirror drive control unit 100 so that the phases of the rotational angle positions of the polygon mirrors PM of each of the 3 scanning units U4 to U6 are rotated at the same speed in a state of being shifted by 15 degrees each time in this order.

Specifically, as shown in fig. 10, for example, the polygon mirror drive control unit 100 controls the rotational phase of the polygon mirror PM of the scanning unit U2 with respect to the 1 st scanning module such that the origin signal SZ2 from the origin sensor OP2 of the scanning unit U2 is generated with a delay time Ts based on the origin signal SZ1 from the origin sensor OP1 of the scanning unit U1. The polygon mirror drive control unit 100 controls the rotational phase of the polygon mirror PM of the scanning unit U3 such that the origin signal SZ3 from the origin sensor OP3 of the scanning unit U3 is delayed by 2×time Ts with respect to the origin signal SZ 1. The time Ts is a time (maximum scanning time of the spot SP) when the polygon mirror PM rotates 15 degrees. Thus, the rotational angle position of the polygon mirror PM of each of the scanning units U1 to U3 is shifted by 15 degrees in the order of U1, U2, and U3. Therefore, the 3 scanning units U1 to U3 of the 1 st scanning module can scan the spot SP in the order of u1→u2→u3.

In the same manner as in the 2 nd scanning module, the polygon mirror drive control unit 100 controls the rotational phase of the polygon mirror PM of the scanning unit U5, for example, such that the origin signal SZ5 from the origin sensor OP5 of the scanning unit U5 is generated with a delay time Ts based on the origin signal SZ4 from the origin sensor OP4 of the scanning unit U4. The polygon mirror drive control unit 100 controls the rotational phase of the polygon mirror PM of the scanning unit U6 such that the origin signal SZ6 from the origin sensor OP6 of the scanning unit U6 is delayed by 2×time Ts with reference to the origin signal SZ 4. Thus, the phases of the rotational angle positions of the polygon mirrors PM of the respective scanning units U4 to U6 are shifted by 15 degrees in the order of U4, U5, and U6. Therefore, the 3 scanning units Un (U4 to U6) of the 2 nd scanning module can scan the spot SP in the order of u4→u5→u6.

The selection element drive control unit (beam switching drive control unit) 102 is a unit for controlling the selection optical elements AOMn (AOM 1 to AOM3, AOM4 to AOM 6) of each optical element module of the beam switching unit BDU, and sequentially distributes the light beams LB (LBa, LBb) from the light source device LS (LSa, LSb) to the 3 scanning units Un (U1 to U3, U4 to U6) of each scanning module after the 1 scanning unit Un of each scanning module starts scanning the light spot SP until the next scanning starts. After the 1 scanning unit Un starts scanning the spot SP and before the next scanning starts, the polygon mirror PM rotates 45 degrees, and the time interval becomes time Tpx (=3×ts).

Specifically, when the origin signal SZn (SZ 1 to SZ 6) is generated, the selection element driving control unit 102 applies driving signals (high frequency signals) HFn (HF 1 to HF 6) to the selection optical elements AOMn (AOM 1 to AOM 6) corresponding to the scanning units Un (U1 to U6) that generate the origin signal SZn (SZ 1 to SZ 6) for a fixed time (on time Ton). By this, the selection optical element AOMn to which the driving signal (high frequency signal) HFn is applied becomes on-state at the on-time Ton, and the light beam LBn can be made incident on the corresponding scanning unit Un. Since the light beam LBn is made incident on the scanning unit Un that generates the origin signal SZn, the light beam LBn can be made incident on the scanning unit Un that can perform scanning of the spot SP. The on-time Ton is a time equal to or less than the time Ts.

Origin signals SZ1 to SZ3 generated in the 3 scanning units U1 to U3 of the 1 st scanning module are generated in the order sz1→sz2→sz3 at intervals of time Ts. Accordingly, the drive signals (high frequency signals) HF1 to HF3 are applied to the selection optical elements AOM1 to AOM3 of the 1 st optical element module at the on-time Ton in the order aom1→aom2→aom3 at the time Ts interval. Therefore, the 1 st optical element module (AOM 1 to AOM 3) can switch the 1 st scanning unit Un on which the light beams LBn (LB 1 to LB 3) from the light source device LSa are incident in the order of u1→u2→u3 at intervals of time Ts. Thereby, the scanning unit Un that scans the spot SP is switched in the order of u1→u2→u3 at intervals of time Ts. In addition, at a time (tpx=3×ts) from the start of scanning of the spot SP by the scanning unit U1 to the start of the next scanning, the light beams LBn (LB 1 to LB 3) from the light source device LSa may be sequentially made incident on any one of the 3 scanning units Un (U1 to U3).

Similarly, origin signals SZ4 to SZ6 generated in the 3 scanning units U4 to U6 of the 2 nd scanning module are generated in the order SZ4→sz5→sz6 at intervals of time Ts. Therefore, the drive signals (high frequency signals) HF4 to HF6 are applied to the respective selection optical elements AOM4 to AOM6 of the 2 nd optical element module at the on-time Ton in the order aom4→aom5→aom6 at the time Ts interval. Therefore, the 2 nd optical element module (AOM 4 to AOM 6) can switch the 1 scanning unit Un on which the light beams LBn (LB 4 to LB 6) from the light source device LSb are incident in the order of u4→u5→u6 at intervals of time Ts. Thereby, the scanning unit Un that scans the spot SP is switched in the order of u4→u5→u6 at intervals of time Ts. In addition, at a time (tpx=3×ts) from the start of scanning of the spot SP by the scanning unit U4 to the start of the next scanning, the light beams LBn (LB 4 to LB 6) from the light source device LSb may be sequentially incident on any one of the 3 scanning units Un (U4 to U6).

When the selection element drive control unit 102 is described in more detail, the selection element drive control unit 102 generates the origin signals SZn (SZ 1 to SZ 6) and then generates a plurality of incidence permission signals LPn (LP 1 to LP 6) that are H (high) for a fixed time (on time Ton) as shown in fig. 10 when the origin signals SZn (SZ 1 to SZ 6) are generated. The plurality of incidence permission signals LPn (LP 1 to LP 6) are signals that permit the corresponding selection optical elements AOMn (AOM 1 to AOM 6) to be in an on state. That is, the incidence permission signals LPn (LP 1 to LP 6) are signals that permit the light fluxes LBn (LB 1 to LB 6) to be incident on the corresponding scanning units Un (U1 to U6). The selection element driving control unit 102 applies driving signals (high-frequency signals) HFn (HF 1 to HF 6) to the corresponding selection optical elements AOMn (AOM 1 to AOM 6) at the on-time Ton at which the incidence permission signals LPn (LP 1 to LP 6) become H (high), and brings the corresponding selection optical elements AOMn into the on-state (a state in which 1-time diffracted light is generated). For example, the selection element driving control unit 102 applies driving signals HF1 to HF3 to the corresponding selection optical elements AOM1 to AOM3 for a fixed time Ton when the incidence permission signals LP1 to LP3 become H (high). Thereby, the light beams LB1 to LB3 from the light source device LSa are incident on the corresponding scanning units U1 to U3. The selection element drive control unit 102 applies drive signals (high-frequency signals) HF4 to HF6 to the corresponding selection optical elements AOM4 to AOM6 at a fixed time Ton when the incidence permission signals LP4 to LP6 become H (high). Thereby, the light beams LB4 to LB6 from the light source device LSb are incident on the corresponding scanning units U4 to U6.

As shown in fig. 10, the incident permission signals LP1 to LP3 corresponding to the 3 selection optical elements AOM1 to AOM3 of the 1 st optical element module are shifted by the time Ts every time the rising timing of H (high) is in the order of LP1, LP2, LP3, and the on-times Ton of H (high) do not overlap with each other. Therefore, the scanning units Un on which the light beams LBn (LB 1 to LB 3) are incident are switched in the order of u1→u2→u3 at intervals of time Ts. Similarly, the incident permission signals LP4 to LP6 corresponding to the 3 selection optical elements AOM4 to AOM6 of the 2 nd optical element module are shifted by the time Ts every time the rising timing of H (high) is in the order of LP4→lp5→lp6, and the on-times Ton of H (high) do not overlap with each other. Therefore, the scanning units Un on which the light beams LBn (LB 4 to LB 6) are incident are switched in the order of u4→u5→u6 at intervals of time Ts. The selection element drive control unit 102 outputs the generated plurality of incidence permission signals LPn (LP 1 to LP 6) to the beam control device 104.

The beam control device (beam control unit) 104 in fig. 9 controls the light emission frequency Fa of the beam LB (LBa, LBb, LBn), the magnification of the drawing line SLn drawn by the spot SP of the beam LB, and the intensity modulation of the beam LB. The beam control device 104 includes an overall magnification setting unit 110, a local magnification setting unit 112, a drawing data output unit 114, and an exposure control unit 116. The overall magnification setting unit (overall magnification correction information storage unit) 110 is a signal generating unit 22a that stores the overall magnification correction information TMg sent from the exposure control unit 116 and outputs the overall magnification correction information TMg to the control circuit 22 of the light source device LS (LSa, LSb). The clock generating section 60 of the signal generating section 22a generates the clock signal LTC of the oscillation frequency Fa corresponding to the whole magnification correction information TMg. The detailed configuration of the entire magnification setting unit 110 and the partial magnification setting unit 112 will be described in detail below.

The local magnification setting unit (local magnification correction information storage unit, correction information storage unit) 112 is a signal generating unit 22a that stores the local magnification correction information (correction information) CMgn transmitted from the exposure control unit 116, and outputs the local magnification correction information CMgn to the control circuit 22 of the light source device LS (LSa, LSb). Based on the partial magnification correction information CMgn, the position of the correction pixel on the drawing line SLn is specified (specified), and the magnification thereof is determined. The signal generating unit 22a of the control circuit 22 outputs pixel shift pulses BSC (BSCa, BSCb) based on the corrected pixel and its magnification determined based on the partial magnification correction information CMg. The local magnification setting unit 112 stores the local magnification correction information CMgn (CMg 1 to CMg 6) for each scanning unit Un (U1 to U6) transmitted from the exposure control unit 116. The local magnification setting unit 112 outputs the local magnification correction information CMgn corresponding to the scanning unit Un that scans the spot SP to the signal generating unit 22a of the light source device LS (LSa, LSb). That is, the local magnification setting unit 112 is a signal generating unit 22a that outputs local magnification correction information CMgn corresponding to the scanning unit Un that generates the origin signal SZn (SZ 1 to SZ 6) to the light source device LSa (LSa, LSb) that is the generation source of the light beam LBn incident on the scanning unit Un. The correction of the drawing magnification based on the whole magnification correction information TMg or the partial magnification correction information CMgn is performed by locally fine-adjusting the clock period of the clock signal LTC from the signal generating unit 22a of the control circuit 22 of the light source device LS (LSa, LSb). The detailed configuration of the control circuit 22 (signal generating unit 22 a) will be described in detail below.

For example, when the scanning unit Un that generates the origin signal SZn (that is, the scanning unit Un that scans the spot SP next) is any one of the scanning units U1 to U3, the local magnification setting unit 112 outputs the local magnification correction information CMgn corresponding to the scanning unit Un that generates the origin signal SZn to the signal generating unit 22a of the light source device LSa. Similarly, when the scanning unit Un that generates the origin signal SZn is any one of the scanning units U4 to U6, the local magnification setting unit 112 outputs the local magnification correction information CMgn corresponding to the scanning unit Un that generates the origin signal SZn to the signal generating unit 22a of the light source device LSb. Accordingly, the pixel shift pulses BSC (BSCa, BSCb) corresponding to the scanning units Un (U1 to U3, U4 to U6) scanning the light spot SP for each scanning module are outputted from the timing switching section 64 for the light source device LS (LSa, LSb). Thus, the scanning length can be individually adjusted for each drawing line SLn.

The drawing data output unit 114 outputs, as drawing bit string data SBa, 1-line serial data DLn corresponding to a scanning unit Un (scanning unit Un for scanning the light spot SP next) that generates the origin signal SZn among the 3 scanning units Un (U1 to U3) of the 1 st scanning module to the driving circuit 36a of the light source device LSa. The drawing data output unit 114 outputs, as the drawing bit string data SBb, the serial data DLn (DL 4 to DL 6) of 1 line corresponding to the scanning unit Un (the scanning unit Un for scanning the light spot SP next) generating the origin signal SZn among the 3 scanning units Un (U4 to U6) of the 2 nd scanning module to the driving circuit 36a of the light source device LSb. In the 1 st scanning module, since the order of the scanning units U1 to U3 for scanning the light spot SP is U1→u2→u3, the drawing data output unit 114 outputs the serial data DL1 to DL3, which are repeated in the order of DL1→dl2→dl3, as the drawing bit string data SBa. In the 2 nd scanning module, since the order of the scanning units U4 to U6 for scanning the light spot SP is U4→u5→u6, the drawing data output unit 114 outputs the serial data DL4 to DL6, which are repeated in the order of DL4→dl5→dl6, as the drawing bit string data SBb.

The exposure control unit 116 shown in fig. 9 controls the overall magnification setting unit 110, the partial magnification setting unit 112, and the drawing data output unit 114. The exposure control unit 116 receives the positional information of the alignment marks MKm (MK 1 to MK 4) on the set azimuth lines Lx1 and Lx4 detected by the mark position detection unit 106 and the rotational angle position information of the rotating drum DR on the set azimuth lines Lx1 to Lx4 detected by the rotational position detection unit 108 (based on the count values of the counter circuits CN1a to CN4a and CN1b to CN4 b). The exposure control unit 116 detects (determines) a start position of the drawing exposure of the exposure target area W in the sub-scanning direction (X direction) of the substrate P based on the positional information of the alignment marks MKm (MK 1 to MK 4) provided on the azimuth line Lx1 and the rotational angle position (count values of the counter circuits CN1a and CN1 b) of the rotating drum DR provided on the azimuth line Lx 1.

The exposure control unit 116 determines whether or not the start position of the drawing exposure of the substrate P has been transferred to the drawing lines SL1, SL3, and SL5 located on the installation azimuth line Lx2, based on the rotation angle position of the rotating drum DR on the installation azimuth line Lx1 and the rotation angle position on the installation azimuth line Lx2 (based on the count values of the counter circuits CN2a and CN2 b) when the start position of the drawing exposure is detected. When the exposure control unit 116 determines that the start position of the drawing exposure has been transferred to the drawing lines SL1, SL3, SL5, it controls the partial magnification setting unit 112, the drawing data output unit 114, and the like, and causes the scanning units U1, U3, and U5 to start the drawing by the scanning of the spot SP.

In this case, the exposure control unit 116 performs the drawing exposure at the scanning units U1 and U3, and causes the local magnification setting unit 112 to output the local magnification correction information CMg1 and CMg3 corresponding to the scanning units U1 and U3 that perform the scanning of the spot SP to the signal generating unit 22a of the light source device LSa. Thus, the signal generating unit 22a of the light source device LSa generates the pixel shift pulse BSCa for shifting the pixels of the serial data DL1, DL3 of the scanning units U1, U3 that scan the light spot SP, based on the partial magnification correction information CMg1, CMg 3. Based on the pixel shift pulse BSCa, the drawing data output unit 114 shifts the logical information of each pixel of the serial data DL1, DL3 corresponding to the scanning units U1, U3 that scan the light spot SP pixel by pixel. Similarly, the exposure control unit 116 performs drawing exposure at the scanning unit U5, and causes the local magnification setting unit 112 to output the local magnification correction information CMg5 corresponding to the scanning unit U5 to the signal generating unit 22a of the light source device LSb. Thus, the signal generating unit 22a of the light source device LSb generates the pixel shift pulse BSCb for shifting the pixel of the serial data DL5 corresponding to the scanning unit U5 for scanning the spot SP, based on the partial magnification correction information CMg 5. Based on the pixel shift pulse BSCb, the drawing data output unit 114 shifts the logical information of each pixel of the serial data DL5 of the scanning unit U5 for scanning the light spot SP pixel by pixel.

Thereafter, the exposure control unit 116 determines whether or not the start position of the drawing exposure of the substrate P has been transferred to the drawing lines SL2, SL4, SL6 located on the installation azimuth line Lx3, based on the rotation angle position of the rotating drum DR on the installation azimuth line Lx1 and the rotation angle position (the count values of the counter circuits CN3a, CN3 b) on the installation azimuth line Lx3 when the start position of the drawing exposure is detected. When determining that the start position of the drawing exposure has been transferred to the drawing lines SL2, SL4, SL6, the exposure control unit 116 controls the partial magnification setting unit 112 and the drawing data output unit 114, and further causes the scanning units U2, U4, U6 to start scanning of the spot SP.

In this case, the exposure control unit 116 causes the local magnification setting unit 112 to output the local magnification correction information CMg2 corresponding to the scanning unit U2 that scans the spot SP to the signal generating unit 22a of the light source device LSa at the timing of the drawing exposure by the scanning unit U2. Thus, the signal generating unit 22a of the light source device LSa generates the pixel shift pulse BSCa for shifting the pixels of the serial data DL2 of the scanning unit U2 for scanning the spot SP based on the partial magnification correction information CMg 2. Based on the pixel shift pulse BSCa, the drawing data output unit 114 shifts the logical information of each pixel of the serial data DL2 of the scanning unit U2 that scans the light spot SP pixel by pixel. Similarly, the exposure control unit 116 performs drawing exposure at the scanning units U4 and U6, and causes the local magnification setting unit 112 to output the local magnification correction information CMg4 and CMg6 corresponding to the scanning units U4 and U6 to the signal generating unit 22a of the light source device LSb. The signal generating unit 22a of the light source device LSb thereby generates the pixel shift pulse BSCb for shifting the pixels of the serial data DL4 and DL6 of the scanning units U4 and U6 for scanning the light spot SP based on the partial magnification correction information CMg4 and CMg 6. Based on the pixel shift pulse BSCb, the drawing data output unit 114 shifts the logical information of each pixel of the serial data DL4, DL6 of the scanning units U4, U6 that scan the light spot SP pixel by pixel.

As is clear from fig. 4, since the substrate P is conveyed in the +x direction, the drawing exposure is performed in each of the drawing lines SL1, SL3, and SL5, and after the substrate P is conveyed a predetermined distance, the drawing exposure is performed in each of the drawing lines SL2, SL4, and SL 6. On the other hand, since the polygon mirror PM of the 3 scanning units U1 to U3 of the 1 st scanning module and the polygon mirror PM of the 3 scanning units U4 to U6 of the 2 nd scanning module are rotated with a specific phase difference, the origin signals SZ1 to SZ3 and SZ4 to SZ6 are continuously generated with a phase difference in time Ts as shown in fig. 10. Accordingly, the incidence permission signals LPn (LP 1 to LP 6) shown in fig. 10 are generated, and the serial data DL2, DL4, DL6 are also outputted from the start time point of the drawing exposure on the drawing lines SL1, SL3, SL5 to the time point immediately before the drawing exposure on the drawing lines SL2, SL4, SL6 starts. Therefore, before the start position of the drawing exposure of the exposure target area W reaches the drawing lines SL2, SL4, SL6, the pattern is drawn by the scanning of the light spots SP by the scanning units U2, U4, U6. Therefore, the exposure control unit 116 in fig. 9 prohibits the shift of the pixels of the serial data DL2, DL4, DL6 corresponding to each of the scanning units U2, U4, U6 by the logic circuit performing the logic operation on the incidence permission signals LPn (LP 1 to LP 6).

The exposure control unit 116 sequentially calculates the strain (deformation) of the substrate P or the exposure region W based on the positional information of the alignment marks MKm (MK 1 to MK 4) on the set azimuth lines Lx1 and Lx4 detected by the mark position detection unit 106 and the rotational angle position information of the rotating drum DR on the set azimuth lines Lx1 and Lx4 detected by the rotational position detection unit 108. For example, when the substrate P is deformed by a large tension in the longitudinal direction or by a thermal process, the shape of the exposed region W is also strained (deformed), and the alignment marks MKm (MK 1 to MK 4) are not aligned in a rectangular shape as shown in fig. 4, and are strained (deformed). When the strain is generated in the substrate P or the exposed region W, the magnification of each drawing line SLn must be changed in response to the strain, and therefore, the exposure control unit 116 generates at least one of the whole magnification correction information TMg and the partial magnification correction information CMgn based on the calculated strain in the substrate P or the exposed region W. At least one of the generated whole magnification correction information TMg and the generated partial magnification correction information CMgn is output to the whole magnification setting unit 110 or the partial magnification setting unit 112. Thus, the precision of the overlapped exposure can be improved.

Furthermore, the exposure control unit 116 may generate corrected inclination angle information for each of the drawing lines SLn according to the strain of the substrate P or the exposure target area W. Based on the generated corrected tilt angle information, the above-described actuators rotate the respective scanning units Un (U1 to U6) around the irradiation center axes Len (Le 1 to Le 6). Thereby, the accuracy of the overlay exposure is further improved. The exposure control unit 116 may generate at least one of the whole magnification correction information TMg and the partial magnification correction information CMgn and the corrected inclination angle information again each time the spot SP is scanned by each scanning unit Un (U1 to U6) or each time the spot SP is scanned a predetermined number of times or each time the tendency of the strain of the substrate P or the exposure target area W is changed beyond the allowable range.

Fig. 11 is a diagram showing a configuration of the signal generating unit 22a provided inside the light source device LSa (LSb). As shown in fig. 9, the local magnification correction information CMgn including the correction position information Nv and the expansion and contraction information (polarity information) POL is transmitted from the local magnification setting unit 112 to the signal generating unit 22 a. The local magnification setting unit 112 stores the local magnification correction information CMgn (CMg 1 to CMg 6) for each scanning unit Un (U1 to U6).

The signal generating section 22a includes a clock signal generating section 200, a correction point specifying section 202, and a clock switching section 204. The clock signal generating section 200, the correction point designating section 202, the clock switching section 204, and the like may be formed by assembling them by an FPGA (Field Programmable Gate Array ). The clock signal generating unit 200 generates a plurality (N) of clock signals CKp (p=0, 1, 2, …, N-1) having a reference period Te shorter than the period specified by Φ/Vs, and imparting a phase difference in units of correction time of 1/N of the reference period Te. Phi is the effective size of the spot SP, vs is the relative velocity of the spot SP with respect to the main scanning direction of the substrate P, and here, as an example, 150mm/sec is explained. When the reference period Te is longer than the period defined by Φ/Vs, the spots SP irradiated along the main scanning direction are irradiated on the irradiated surface of the substrate P at predetermined intervals. Conversely, when the reference period Te is shorter than the period defined by Φ/Vs, the spots SP are irradiated onto the irradiated surface of the substrate P so as to overlap each other in the main scanning direction. In the present embodiment, in principle, the spot SP is overlapped by 1/2 of the size Φ each time, and for this purpose, the oscillation frequency Fe is set to 100MHz. In this case, the reference period Te is 1/fe=1/100 [ MHz ] =10 [ nsec ], and is smaller than Φ/vs=3 [ μm ]/150 [ mm/sec ] =20 nsec. If n=50, the clock signal generating unit 200 generates 50 clock signals CK0 to CK49 to which a phase difference of 0.2nsec (=10 nsec/50) is applied.

Specifically, the clock signal generating section 200 includes a clock generating section (oscillator) 60 and a plurality of (N-1) delay circuits De (De 01 to De 49). The clock generation section 60 generates a clock signal CK0 composed of clock pulses oscillating at an oscillation frequency Fe (=1/Te) corresponding to the whole magnification correction information TMg. In the present embodiment, the clock generation unit 60 generates the clock signal CK0 at the oscillation frequency Fe of 100MHz (reference period te=10 nsec) with the whole magnification correction information TMg set to 0 (correction amount 0%).

The clock signal (output signal) CK0 from the clock generating section 60 is input to the first (front) delay circuit De01 of the plurality of delay circuits De (De 01 to De 49) connected in series, and is input to the 1 st input terminal of the clock switching section 204. The delay circuits De (De 01 to De 049) delay the clock signal CKp as an input signal by a fixed time (Te/n=0.2 nsec) and output the delayed clock signal CKp. Accordingly, the first-stage delay circuit De01 outputs a clock signal (output signal) CK1, and the clock signal (output signal) CK1 has the same reference period Te (10 nsec) as the clock signal CK0 generated by the clock generating section 60 and has a delay of 0.2nsec with respect to the clock signal CK0. Similarly, the 2 nd stage delay circuit De02 outputs a clock signal (output signal) CK2, the clock signal (output signal) CK2 being the same reference period Te (10 nsec) as the clock signal (output signal) CK1 from the preceding stage delay circuit De01 and having a delay of 0.2nsec with respect to the clock signal CK 1. The delay circuits De03 to De49 after the 3 rd stage similarly output clock signals (output signals) CK3 to CK49, and the clock signals (output signals) CK3 to CK49 have the same reference period Te (10 nsec) as the clock signals (output signals) CK2 to CK48 from the delay circuits De02 to De48 in the preceding stage, and have a delay of 0.2nsec with respect to the clock signals CK2 to CK 48.

Since the clock signals CK0 to CK49 are signals to which a phase difference is given every 0.2nsec, the clock signal CK0 is a signal which has the same reference period Te (10 nsec) as the clock signal CK49 and which has a delay of 0.2nsec with respect to the clock signal CK49 and is shifted by exactly 1 period. Therefore, the clock signal CK0 can be regarded as a clock signal delayed by 0.2nsec with respect to each clock pulse of the clock signal CK 49. The clock signals CK1 to CK49 from the delay circuits De01 to De49 are input to the 2 nd to 50 th input terminals of the clock switching section 204.

The clock switching unit 204 is a multiplexer (selection circuit) that selects any one of the 50 clock signals CKp (CK 0 to CK 49) to be input and outputs the selected clock signal CKp as the clock signal (reference clock signal) LTC. Therefore, the oscillation frequency Fa (=1/Ta) of the clock signal LTC is basically the same as the oscillation frequency Fe (=1/Ta) of the clock signals CK0 to CK49, that is, 100MHz. The control circuit 22 controls the DFB semiconductor laser devices 30 and 32 so as to emit the seed lights S1 and S2 in response to the respective clock pulses of the clock signal LTC outputted from the clock switching section 204. Therefore, the oscillation frequency Fa of the pulse-like light beam LBa (LBb) emitted from the light source device LSa (LSb) is 100MHz in principle.

The clock switching unit 204 switches the clock signal CKp outputted as the clock signal LTC, that is, the clock signal CKp generated by the light beam LBa (LBb), to another clock signal CKp having a different phase difference at the timing when the light spot SP passes through the specific correction point CPP located on the scanning line. The clock switching unit 204 switches the clock signal CKp selected as the clock signal LTC to the clock signal ckp±1 having a phase difference of 0.2nsec with respect to the clock signal CKp currently selected as the clock signal LTC at the timing when the light spot SP passes the correction point CPP. The direction of the phase difference of the switched clock signal ckp±1, that is, the direction of the phase delay of 0.2nsec or the direction of the phase advance of 0.2nsec is determined based on 1-bit stretch information (polarity information) POL which is a part of the partial magnification correction information (correction information) CMgn (CMg 1 to CMg 6).

In the case where the expansion information POL is high "1" (expansion), the clock switching unit 204 selects and outputs the clock signal ckp+1, which is phase-delayed by 0.2nsec with respect to the clock signal CKp currently output as the clock signal LTC, as the clock signal LTC. In the case where the expansion information POL is low "0" (reduced), the clock switching unit 204 selects and outputs the clock signal CKp-1 whose phase is advanced by 0.2nsec with respect to the clock signal CKp currently output as the clock signal LTC. For example, when the current clock signal CKp output as the clock signal LTC is CK11, the clock switching unit 204 switches the clock signal CKp output as the clock signal LTC to the clock signal CK12 when the expansion information POL is high (H), and switches the clock signal CKp output as the clock signal LTC to the clock signal CK10 when the expansion information POL is low (L). The same expansion information POL is input during 1 scanning period of the spot SP.

The clock switching unit 204 determines the direction of the phase shift (the direction of the phase advance or the direction of the delay) of the clock signal CKp output as the clock signal LTC, using the expansion/contraction information POL of the local magnification correction information CMgn corresponding to the scanning unit Un into which the light beam LBn is incident by the light beam switching unit BDU. The light beams LBa (LB 1 to LB 3) from the light source device LSa are guided to any one of the scanning units U1 to U3. Therefore, the clock switching unit 204 of the signal generating unit 22a of the light source device LSa determines the direction of the phase shift of the clock signal CKp outputted as the clock signal LTC based on the expansion and contraction information POL of the local magnification correction information CMgn corresponding to the 1 scanning unit Un to which the light beam LBn is incident among the scanning units U1 to U3. For example, when the light beam LB2 is incident on the scanning unit U2, the clock switching unit 204 of the light source device LSa determines the direction of the phase shift of the clock signal CKp outputted as the clock signal LTC based on the expansion/contraction information POL of the local magnification correction information CMg2 corresponding to the scanning unit U2.

The light beams LBb (LB 4 to LB 6) from the light source device LSb are guided to any one of the scanning units U4 to U6. Therefore, the clock switching unit 204 of the signal generating unit 22a of the light source device LSb determines the direction of the phase shift of the clock signal CKp outputted as the clock signal LTC based on the expansion and contraction information POL of the local magnification correction information CMgn corresponding to the 1 scanning unit Un to which the light beam LBn is incident among the scanning units U4 to U6. For example, when the light beam LB6 is incident on the scanning unit U6, the clock switching unit 204 of the light source device LSb determines the direction of the phase shift of the clock signal CKp outputted as the clock signal LTC based on the expansion/contraction information POL of the local magnification correction information CMg6 corresponding to the scanning unit U6.

The correction point specification unit 202 specifies a specific point on each drawing line SLn (SL 1 to SL 6) as a correction point CPP. The correction point specification unit 202 specifies the correction point CPP based on correction position information (set value) Nv for specifying the correction point CPP, which is a part of the partial magnification correction information (correction information) CMgn (CMg 1 to CMg 6). The correction position information Nv of the partial magnification correction information CMgn is information for specifying the correction point CPP at each of a plurality of positions that are dispersed at equal intervals on the drawing line SLn according to the drawing magnification of the pattern drawn along the drawing line SLn (or the drawing magnification in the main scanning direction of the drawing line SLn), and is information indicating the distance interval (equal interval) between the correction point CPP and the correction point CPP. Thus, the correction point specification unit 202 can specify positions on the drawing lines SLn (SL 1 to SL 6) that are discretely arranged at equal intervals as the correction point CPP. The correction point CPP is set between the projection positions (the center positions of the light spots SP) of the adjacent 2 light spots SP projected along the drawing line SLn, for example.

The correction point specification unit 202 specifies the correction point CPP using the correction position information Nv of the partial magnification correction information CMgn corresponding to the scanning unit Un into which the light beam LBn is incident by the light beam switching unit BDU. Since the light fluxes LBa (LB 1 to LB 3) from the light source device LSa are guided to any one of the scanning units U1 to U3, the correction point specification unit 202 specifies the correction point CPP based on the correction position information Nv of the partial magnification correction information CMgn corresponding to 1 scanning unit Un on which the light flux LBn is incident in the scanning units U1 to U3. For example, when the light beam LB2 is incident on the scanner unit U2, the correction point specification unit 202 of the light source device LSa specifies a plurality of positions, which are discretely arranged at equal intervals on the drawing line SLn2, as correction points CPP based on the correction position information Nv of the partial magnification correction information CMg2 corresponding to the scanner unit U2.

Since the light fluxes LBb (LB 4 to LB 6) from the light source device LSb are guided to any one of the scanning units U4 to U6, the correction point specification unit 202 of the signal generation unit 22a of the light source device LSb specifies the correction point CPP based on the correction position information Nv of the partial magnification correction information CMgn corresponding to 1 scanning unit Un on which the light flux LBn is incident among the scanning units U4 to U6. For example, when the light beam LB6 is incident on the scanning unit U6, the correction point specification unit 202 of the light source device LSb specifies a plurality of positions, which are discretely arranged at equal intervals on the drawing line SLn6, as correction points CPP based on the correction position information Nv of the partial magnification correction information CMg6 corresponding to the scanning unit U6.

To describe the correction point specification unit 202 specifically, the correction point specification unit 202 includes a frequency division counter circuit 212 and a shift pulse output unit 214. The frequency-division counter circuit 212 is a down counter, and is inputted with a clock pulse (reference clock pulse) of the clock signal LTC outputted from the clock switching section 204. The clock pulse of the clock signal LTC outputted from the clock switching section 204 is inputted to the frequency division counter circuit 212 via the gate circuit GTa. The drawing permission signals SQ1 to SQ3 indicating the drawing periods of the respective scanning units U1 to U3 are logically summed and applied to the gate circuit GTa. The drawing permission signals SQ1 to SQ3 are generated in response to the incident permission signals LP1 to LP3 of fig. 10. The gate circuit GTa is a gate that is opened during a period in which the drawing enable signal SQn is high (H). That is, the frequency-division counter circuit 212 counts the clock pulses of the clock signal LTC only in a period in which the drawing enable signal SQn is high. Therefore, the gate circuit GTa of the light source device LSa outputs the clock pulse of the clock signal LTC, which is input during the period when any one of the drawing enable signals SQ1 to SQ3 is high (H), to the frequency division counter circuit 212. Similarly, 3 drawing enable signals SQ4 to SQ6 corresponding to the scan cells U4 to U6 are applied to the gate circuit GTa of the signal generating unit 22a of the light source device LSb. Therefore, the gate circuit GTa of the light source device LSb outputs the clock pulse of the clock signal LTC, which is input during the period when any of the drawing enable signals SQ4 to SQ6 is high (H), to the frequency division counter circuit 212.

The frequency division counter circuit 212 is an initial count value preset as correction position information (set value) Nv, and decrements the count value every time a clock pulse of the clock signal LTC is input. The frequency division counter circuit 212 outputs the 1-pulse coincidence signal Idc to the shift pulse output section 214 when the count value becomes 0. That is, the frequency division counter circuit 212 outputs the coincidence signal Idc when counting clock pulses of the clock signal LTC by the corrected position information Nv. The coincidence signal Idc is information indicating that the correction point CPP exists before the next clock pulse is generated. When the next clock pulse is input after the count value becomes 0, the frequency division counter circuit 212 presets the count value as the corrected position information Nv. Thus, a plurality of correction points CPP can be specified at equal intervals along the drawing line SLn.

When the coincidence signal Idc is input, the shift pulse output unit 214 outputs the shift pulse CS to the clock switching unit 204. When the shift pulse CS is generated, the clock switching unit 204 switches the clock signal CKp outputted as the clock signal LTC. The shift pulse CS is information indicating the correction point CPP, and is generated after the count value of the frequency division counter circuit 212 becomes 0 and before the next clock pulse is input. Therefore, a correction point CPP exists between the position on the substrate P of the spot SP of the light beam LBa (LBb) generated according to the clock pulse that makes the count value of the frequency division counter circuit 212 0 and the position on the substrate P of the spot SP of the light beam LBa (LBb) generated according to the next clock pulse.

As described above, when 20000 light spots SP are projected on each 1 drawing line SLn and 40 correction points CPP are discretely arranged at equal intervals on the drawing line SLn, the correction points CPP are arranged at intervals of 500 light spots SP (clock pulses of the clock signal LTC), and the correction position information Nv is set to 500.

Fig. 12 is a timing chart showing signals output from each section of the signal generating section 22a shown in fig. 11. The 50 clock signals CK0 to CK49 generated by the clock signal generating unit 200 are each the same reference period Te as the clock signal CK0 outputted by the clock generating unit 60, but each time the phase thereof is delayed by 0.2nsec. Therefore, for example, the clock signal CK3 is phase-delayed by 0.6nsec with respect to the clock signal CK0, and the clock signal CK49 is phase-delayed by 9.8nsec with respect to the clock signal CK 0. The frequency-division counter circuit 212 outputs a coincidence signal Idc (not shown) when counting the clock pulses of the clock signal LTC output from the clock switching section 204 in accordance with the corrected position information (set value) Nv, and the shift pulse output section 214 outputs a shift pulse CS in accordance therewith. The shift pulse output unit 214 outputs a shift pulse CS that normally outputs a high (logical value 1) signal, but decreases to a low (logical value 0) when the coincidence signal Idc is output, and increases to a high (logical value 1) when a half (half period) of the reference period Te of the clock signal CKp elapses. Thus, the shift pulse CS rises after the clock pulse of the clock signal LTC is counted by the frequency division counter circuit 212 by the corrected position information (set value) Nv amount and before the next clock pulse is input.

The clock switching unit 204 switches the clock signal CKp outputted as the clock signal LTC to the clock signal ckp±1 obtained by shifting the phase of the clock signal CKp outputted immediately before the generation of the shift pulse CS by 0.2nsec in the direction corresponding to the expansion/contraction information POL' in response to the rising of the shift pulse CS. In the example of fig. 12, since the clock signal CKp output as the clock signal LTC immediately before the shift pulse CS is generated is CK0 and the expansion information POL is "0" (reduced), the shift pulse CS is switched to the clock signal CK49 in response to the rising of the shift pulse CS. In this way, when the expansion information POL is "0", the clock switching unit 204 switches the clock signal CKp outputted as the clock signal LTC so that the phase is advanced by 0.2nsec each time the spot SP passes the correction point CPP (i.e., each time the shift pulse CS is generated). Therefore, the clock signal CKp outputted (selected) as the clock signal LTC is switched in the order CK0→CK49→CK48→CK47→. At the position of the correction point CPP generated by the shift pulse CS, the period of the clock signal LTC is set to be 0.2nsec (9.8 nsec) shorter than the reference period Te (=10 nsec), and thereafter, before the light spot SP passes the next correction point CPP (before the next shift pulse CS is generated), the period of the clock signal LTC is set to the reference period Te (=10 nsec).

Conversely, in the case where the expansion information POL is "1", the clock switching unit 204 switches the clock signal CKp outputted (selected) as the clock signal LTC with a phase delay of 0.2nsec each time the spot SP passes the correction point CPP (i.e., each time the shift pulse CS is generated). Therefore, the clock signal CKp outputted (selected) as the clock signal LTC is switched in the order CK0→CK1→CK2→CK3→. At the position of the correction point CPP generated by the shift pulse CS, the period of the clock signal LTC is 0.2nsec longer than the reference period Te (=10 nsec) (10.2 nsec), and thereafter, before the light spot SP passes the next correction point CPP (before the next shift pulse CS is generated), the period of the clock signal LTC is the reference period Te (=10 nsec).

In the present embodiment, since the light spots SP having an effective size Φ of 3 μm are projected in the main scanning direction so as to overlap 1.5 μm each time, the correction time (±0.2 nsec) of the period of the clock signal LTC at the correction point CPP corresponds to 0.03 μm (=1.5 μm) × (±0.2 nsec/10 nsec)), and extends and contracts ±0.03 μm for each 1 pixel.

Fig. 13A is a diagram illustrating a pattern PP drawn when the partial magnification correction is not performed, and fig. 13B is a diagram illustrating a pattern PP drawn when the partial magnification correction (reduction) is performed according to the timing chart shown in fig. 12. The light spot SP with high intensity is shown by a solid line, and the light spot SP with low or zero intensity is shown by a broken line. As shown in fig. 13A and 13B, the light spot SP generated in response to each clock pulse of the clock signal LTC depicts the pattern PP. In order to distinguish the clock signal LTC and pattern PP of fig. 13A and 13B, the clock signal LTC and pattern PP of fig. 13A (when the local magnification correction is not performed) are represented by LTC1 and PP1, and the clock signal LTC and pattern PP of fig. 13B (when the local magnification correction is performed) are represented by LTC2 and PP 2.

When the partial magnification correction is not performed, the size Pxy of each depicted pixel becomes a fixed length in the main scanning direction, as shown in fig. 13A. The length of the pixel in the sub-scanning direction (X direction) is denoted by Px, and the length of the pixel in the main scanning direction (Y direction) is denoted by Py. When the partial magnification correction (reduction) is performed based on the time chart shown in fig. 12, the pixel size Pxy including the correction point CPP is reduced by Δpy (=0.03 μm) as shown in fig. 13B. Conversely, when the local magnification correction of the extension is performed, the pixel size Pxy including the correction point CPP is set in a state where the pixel length Py is extended by Δpy (=0.03 μm).

Although not particularly mentioned, the drawing data output unit 114 shown in fig. 9 shifts the logic information of the pixels of the serial data DLn outputted to the driving circuit 36a of the light source device LSa (LSb) by 1 pixel amount (1 bit amount) every time the clock pulse of the clock signal LTC is outputted by 2 from the clock switching unit 204. Thus, 2 spots SP (clock pulses of clock signal LTC) correspond to 1 pixel.

As described above, the exposure apparatus EX of the present embodiment modulates the intensity of the spot SP of the light beam LB (Lse, LBa, LBb, LBn) generated from the seed light S1, S2 from the pulse light source unit 35 based on the pattern data, and scans the spot SP along the drawing line SLn on the substrate P so as to draw a pattern on the substrate P. The exposure apparatus EX includes at least a clock signal generating section 200, a control circuit (light source control section) 22, and a clock switching section 204. As described above, the clock signal generating section 200 generates a plurality of (n=50) clock signals CKp (CK 0 to CK 49) having a reference period Te (for example, 10 nsec) shorter than the period determined by Φ/Vs, and imparting a phase difference in units of a correction time (for example, 0.2 nsec) of 1/N of the reference period Te. The control circuit (light source control unit) 22 controls the pulse light source unit 35 so as to generate the light beam LB in response to each clock pulse of any one of the plurality of clock signals CKp (clock signal LTC). The clock switching unit 204 switches the clock signal CKp generated by the light beam LB, that is, the clock signal CKp outputted as the clock signal LTC, to another clock signal CKp having a different phase difference at the timing when the light spot SP passes through the specific correction point CPP designated on the drawing line SLn. Therefore, the magnification of the drawing line SLn (drawn pattern) can be finely corrected, and precise overlay exposure on the micrometer scale can be performed.

The correction position information (set value) Nv of the partial magnification correction information CMgn (CMg 1 to CMg 6) can be arbitrarily changed and appropriately set according to the magnification of the drawing line SLn. For example, the correction position information Nv may be set so that the correction point CPP located on the drawing line SLn becomes 1. The value of the correction position information Nv may be changed every 1 scan of the light spot SP along the drawing line SLn, or may be changed every time the light spot SP is located at the correction point CPP in 1 scan. In this case, the case where a plurality of correction points CPP are designated at discrete positions on the drawing line SLn is also unchanged, but the intervals of the correction points CPP may be made uneven by changing the correction position information Nv. Further, the number of correction pixels on the drawing line SLn may be set to be constant and the positions of the correction pixels (correction points CPP) may be set to be different for every 1 scan of the light beam LBn (light spot SP) along the drawing line SLn or every 1 rotation of the polygon mirror PM.

Modification of embodiment 1

The following modifications are possible in embodiment 1. The same components as those of the above embodiment will be denoted by the same reference numerals, and the description will be focused on different portions.

Modification 1

In embodiment 1, the selection optical elements AOMn (AOM 1 to AOM 6) for selectively supplying the light beam LBa (LBb) from the light source device LSa (LSb) to any one of the scanning units Un (U1 to U6) are used as the acousto-optic modulator. That is, the 1 st-order diffracted light, which is output after deflecting the incident beam at a specific diffraction angle, is supplied to the scanning unit Un as the drawing beam LBn, but the optical elements AOMn (AOM 1 to AOM 6) may be selected as photoelectric deflecting members that do not use diffraction phenomena. Fig. 14 shows a configuration of a beam switching unit corresponding to 1 scanning unit Un in the beam switching unit BDU of modification 1, in which, instead of the combination system of the selection optical element AOM1 and the unit-side incident mirror IM1 shown in fig. 6, a photoelectric element OSn that allows the light beam LBa (LBb) from the light source device LSa (LSb) to enter and a polarization beam splitter BSn that allows the light beam to pass through or reflect according to the polarization characteristics of the light beam having passed through the photoelectric element OSn are provided.

In fig. 14, the light beam LBa (LBb) emitted from the light source device LSa (LSb) as a parallel light beam is set to be linearly polarized light in which the light beam LBa (LBb) incident on the photocell OSn is polarized in the Y direction when the light beam is parallel to the X axis, and when a voltage of several Kv is applied between the electrodes EJp, EJm formed on the surface of the photocell OSn facing in the Y direction, the light beam having transmitted through the photocell OSn is rotated 90 degrees from the polarized light state at the time of incidence and is polarized in the Z direction, and is incident on the polarization beam splitter BSn. When no voltage is applied between the electrodes EJp and EJm, the light beam transmitted through the photoelectric element OSn becomes linearly polarized light polarized in the Y direction while maintaining the polarized state at the time of incidence. Therefore, in the off state where the voltage between the electrodes EJp and EJm is zero, the light flux from the photoelectric element OSn directly passes through the polarization splitting plane psp (a plane inclined by 45 degrees with respect to each of the XY plane and the YZ plane) of the cube-shaped polarization beam splitter BSn. In the on state in which a voltage is applied between the electrodes EJp, EJm, the light beam from the photocell OSn is reflected on the polarization splitting plane psp of the polarization beam splitter BSn, becomes a drawing light beam LBn subjected to intensity modulation based on drawing data (for example, drawing bit string data SBa, SBb in fig. 9), and is directed to the scanning unit Un. The photocell OSn is composed of a crystalline medium or an amorphous medium exhibiting the pecker effect of which refractive index varies to the power of 1 of the applied electric field intensity, or the pecker effect of which refractive index varies to the power of 2 of the applied electric field intensity. The optoelectronic element OSn may be a crystal medium exhibiting a faraday effect in which the refractive index is changed by a magnetic field instead of an electric field.

Modification 2

Fig. 15 shows a modification 2 of the case where the selection optical elements AOM1 to AOM6 constituting the beam switching unit BDU shown in fig. 6 and the unit-side incident mirrors IM1 to IM6 are replaced with the configuration of modification 1 of fig. 14. The linearly polarized light beam LBa emitted as a parallel light beam (beam diameter of 1mm or less) from the light source device LSa passes through the beam shifter unit SFTa using the acousto-optic modulator (or acousto-optic deflector) shown in fig. 6 and 9, sequentially passes through the photoelectric element OS1, the polarization beam splitter BS1, the photoelectric element OS2, the polarization beam splitter BS2, the photoelectric element OS3, and the polarization beam splitter BS3, and then enters the absorber TR1. The polarization beam splitter BS1 reflects the light beam LBa as the drawing light beam LB1 toward the scanning unit U1 when an electric field is applied to the photocell OS 1. Similarly, the polarization beam splitter BS2 reflects the light beam LBa as the drawing light beam LB2 toward the scanning unit U2 when the electric field is applied to the photocell OS2, and the polarization beam splitter BS3 reflects the light beam LBa as the drawing light beam LB3 toward the scanning unit U3 when the electric field is applied to the photocell OS 3. In fig. 15, an electric field is applied only to the photocell OS2 among the photocells OS1 to OS3, and the light beam LBa emitted from the beam shifter portion SFTa is incident only on the scanning unit U2 as the light beam LB 2.

Similarly, a linearly polarized light beam LBb emitted as a parallel light beam (beam diameter of 1mm or less) from the light source device LSb passes through the beam shifter unit SFTb using an acousto-optic modulator (or acousto-optic deflector), sequentially passes through the photoelectric element OS4, the polarizing beam splitter BS4, the photoelectric element OS5, the polarizing beam splitter BS5, the photoelectric element OS6, and the polarizing beam splitter BS6, and then enters the absorber TR2. The polarization beam splitter BS4 reflects the light beam LBb as the drawing light beam LB4 toward the scanning unit U4 when the electric field is applied to the photocell OS4, the polarization beam splitter BS5 reflects the light beam LBb as the drawing light beam LB5 toward the scanning unit U5 when the electric field is applied to the photocell OS5, and the polarization beam splitter BS6 reflects the light beam LBb as the drawing light beam LB6 toward the scanning unit U6 when the electric field is applied to the photocell OS 6. In fig. 15, an electric field is applied only to the photocell OS6 among the photocells OS4 to OS6, and the light beam LBb emitted from the beam shifter section SFTb is incident only on the scanning unit U6 as the light beam LB 6.

As an example, the beam shifter sections SFTa and SFTb are configured as shown in fig. 16 using an acousto-optic deflector AODs. The acousto-optic deflection devices AODs are driven by the same high-frequency drive signals HGa, HGb as the drive signal HFn as the high-frequency power from the selection device drive control section 102 shown in fig. 9. The parallel light beam LBa (LBb) from the light source device LSa (LSb) is incident coaxially with the optical axis of the lens CG1 of the focal length f1, and is condensed on the surface pu so as to become a beam waist. The deflection point of the acousto-optic deflection element AODs is arranged at the position of the plane pu. In a state where the drive signal HGa (HGb) is turned off, the light beam LBa (LBb) having a beam waist on the surface pu is not diffracted, and is incident on the lens CG2 having the focal length f2 from the surface pu, and is reflected by the mirror OM and is incident on the absorber TR3 as a parallel light beam. When the drive signal HGa (HGb) is applied to the on state of the acousto-optic deflection element AODs, the acousto-optic deflection element AODs generates 1 st diffraction light of the beam LBa (LBb) deflected at a winding angle corresponding to the frequency of the drive signal HGa (HGb). This 1 st diffraction light is referred to herein as deflected light beam LBa (LBb). Since the deflection point of the acousto-optic deflection element AODs is arranged on the plane pu which is the position of the focal length f2 of the lens CG2, the light beam LBa (LBb) emitted from the lens CG2 becomes a parallel light beam parallel to the optical axis of the lens CG2, and is incident on the photocell OS1 or OS4 of fig. 15.

By changing the frequency of the driving signal HGa (HGb) applied to the acousto-optic deflection element AODs, the light beam LBa (LBb) emitted from the lens CG2 is shifted in position in the direction perpendicular to the optical axis in a state parallel to the optical axis of the lens CG 2. The direction of the positional shift of the light beam LBa (LBb) corresponds to the Z direction on the incident end face of the photocell OSn (OS 1 or OS 4) shown in fig. 14, and the shift amount corresponds to the amount of change in the frequency of the driving signal HGa (HGb). In the case of the present modification, the beam shifter unit SFTa (SFTb) is provided in common to the 3 scanning units U1, U2, and U3 (U4, U5, and U6). Therefore, the frequency of the driving signal HGa (HGb) applied to the acousto-optic deflection element AODs can be changed (frequency modulation) in synchronization with the timing at which any one of the photocells OS1 to OS3 or any one of the photocells OS4 to OS6 in the on state of fig. 15. By this, the light fluxes LBa (LBb) passing through the photocells OS1 to OS3 (OS 4 to OS 6) are shifted in parallel to the Z direction in fig. 14, and the light fluxes LBn (LB 1 to LB 6) reflected by the polarization beam splitters BS1 to BS3 (BS 4 to BS 6) are shifted in parallel to the X direction in fig. 14. By this, the spot SP of the light beam LBn from the scanning unit Un corresponding to the photocell OSn that has been turned on can be rapidly shifted by a small amount in the sub-scanning direction (X direction).

As described above, in the present embodiment, in order to selectively distribute the light beam LBa (LBb) from the light source device LSa (LSb) to any one of the 3 scanning units U1 to U3 (U4 to U6), the photocells OS1 to OS3 (OS 4 to OS 6) having no deflection function are used, and therefore, in order to fine-adjust the position of the light spot SP in the sub-scanning direction, the beam shifter section SFTa (SFTb) using the acousto-optic deflection element AODs having a deflection function is provided.

Modification 3

Fig. 17A and 17B show an example of a beam deflection member that is provided instead of the selection optical elements AOM1 to AOM6 or the acousto-optic deflection elements AODs used in the above-described embodiment or modification and that does not use diffraction. Fig. 17A shows a photovoltaic element ODn in which electrodes EJp, EJm are formed on opposite parallel side surfaces (upper and lower surfaces in fig. 17A) of a transparent crystalline medium formed in a prism shape (triangle shape) with a specific thickness. The crystal medium is a material represented by KDP (KH 2PO 4), ADP (NH 4H2PO 4), kd×p (KD 2PO 4), KDA (KH 2AsO 4), baTiO3, srTiO3, liNbO3, liTaO3, or the like as a chemical composition. The light beam LBa (LBb) incident from one inclined surface of the photoelectric element ODn is deflected according to the difference between the initial refractive index of the crystal medium and the refractive index of air when the electric field between the electrodes EJp, EJm is zero, and is emitted from the other inclined surface. When an electric field of a fixed value or more is applied between the electrodes EJp, EJm, the refractive index of the crystal medium changes from an initial value, and therefore, the incident light beam LBa (LBb) becomes a light beam LBn emitted from the other inclined surface at an angle different from the initial angle. Even if such a photocell ODn is used, the light beam LBa (LBb) from the light source device LSa (LSb) can be switched in a time-sharing manner and supplied to each of the scanning units U1 to U6. Further, by changing the electric field intensity applied to the photocell ODn, the deflection angle of the emitted light beam LBn can be changed slightly and rapidly, and therefore, the photocell ODn can also have both a switching function and a light beam shifting function of slightly shifting the light spot SP on the substrate P in the sub-scanning direction. Further, instead of the acousto-optic deflection element AODs of the individual beam shifter section SFTa (SFTb) as shown in fig. 16, the photo-electric element ODn may be used.

Fig. 17B shows an example of a beam deflection member using a photoelectric element KDn using KTN (KTa 1-xNbxO 3) crystal as disclosed in, for example, japanese patent application laid-open No. 2014-081575 and international publication No. 2005/124398. In fig. 17B, the photocell KDn is composed of a crystal medium formed in a long angular column shape along the advancing direction of the light beam LBa (LBb), and electrodes EJp, EJm disposed opposite to each other with the crystal medium interposed therebetween. The photovoltaic element KDn is housed in a case having a temperature control function so as to be maintained at a fixed temperature (for example, about 40 degrees). When the electric field intensity between the electrodes EJp and EJm is zero, the light beam LBa (LBb) incident from one end face of the KTN crystal medium in the shape of a rectangular column advances straight in the KTN crystal medium, and is emitted from the other end face. When an electric field strength is applied between the electrodes EJp and EJm, the light beam LBa (LBb) passing through the KTN crystal medium is deflected in the direction of the electric field, and is emitted as a light beam LBn from the other end face. KTN crystalline media are also materials whose refractive index varies according to the electric field strength, but a large refractive index variation is obtained with an electric field strength one bit lower (several hundred V) than the various crystalline media listed above. Therefore, by changing the voltage applied between the electrodes EJp and EJm, the deflection angle of the light beam LBn emitted from the photocell KDn with respect to the original light beam LBa (LBb) can be quickly adjusted over a relatively large range (for example, 0 degrees to 5 degrees).

Even if such a photocell KDn is used, the light beam LBa (LBb) from the light source device LSa (LSb) can be switched in a time-sharing manner and supplied to each of the scanning units U1 to U6. Further, by changing the electric field intensity applied to the photocell KDn, the deflection angle of the emitted light beam LBn can be quickly changed, and therefore, the photocell KDn can also have both a switching function and a function of shifting the light spot SP on the substrate P in the sub-scanning direction. Further, instead of the acousto-optic deflection element AODs of the individual beam shifter section SFTa (SFTb) shown in fig. 16, a photo-electric element KDn may be used.

According to embodiment 1 or modifications thereof described above, in order to shift the light spot SP scanned along the drawing line SLn in the sub-scanning direction, a mechano-optical phase shifter using the shift optical member SR (parallel plate SR 2) provided in each of the scanning units Un (U1 to U6) and a photo-electric phase shifter using the acousto-optic deflection element AODs, the photo-electric element OSn, ODn, KDn, or the like to shift the light beam LBn incident on each of the scanning units Un (U1 to U6) are provided. Therefore, when the positional relationship in the sub-scanning direction of the drawing line SLn based on the scanning of the spot SP of each of the light beams LBn from the scanning units Un (U1 to U6) is set to a specific state (initial arrangement state or the like), the mechanical optical phase shifter (parallel plate Sr 2) is used for correction (calibration), and even if the correction is performed, the amount of error remaining can be corrected more finely by the electro-optical phase shifter (acousto-optical deflection elements AODs, electro-optical elements OSn, ODn, KDn).

[ embodiment 2 ]

Next, embodiment 2 will be described. The same components as those of the above-described embodiment (including the modification) are denoted by the same reference numerals, and only different portions will be described. In the configuration of fig. 6 described as the above embodiment, a plurality of beam waists (condensed spots) are formed for the light beam LBa (LBb) from the light source device LSa (LSb) by a plurality of relay systems based on the condenser lens CD and the collimator lens (collimator lens) LC, and the selection optical elements (acousto-optic modulators) AOM1 to AOM6 are arranged at the positions of the beam waists. Since the beam waist position of the beam LBa (LBb) is set so as to be optically conjugate with the surface of the substrate P (each spot SP of the beams LB1 to LB 6), even if an error occurs in the deflection angle due to a characteristic change or the like of the optical elements (acousto-optic modulator) AOM1 to AOM6, the spot SP on the substrate P can be suppressed from drifting in the sub-scanning direction (Xt direction). Therefore, when the drawing line SLn of the optical dot SP is finely adjusted in the sub-scanning direction (Xt direction) in the pixel size (several μm) range for each scanning unit Un, the parallel flat plate Sr2 in the scanning unit Un shown in fig. 5 may be inclined. Further, in order to automate the tilting of the parallel plate Sr2, a mechanism such as a small piezoelectric motor or a monitor system for tilting may be provided.

However, even if the tilting of the parallel flat plate Sr2 is automated, since it is mechanically driven, for example, it is difficult to control the polygon mirror PM with high responsiveness corresponding to the time of 1-rotation amount of the polygon mirror PM. Therefore, in embodiment 2, the optical configuration or arrangement of the beam transmission system (beam switching unit BDU) from the light source device LS (LSa, LSb) to each scanning unit Un as shown in fig. 7 is slightly changed, and the selection optical elements (acousto-optic modulator) AOM1 to AOM6 have both the function of switching the beam and the function of shifting the position of the optical spot SP in the sub-scanning direction. The configuration of embodiment 2 will be described below with reference to fig. 18 to 22.

Fig. 18 is a diagram showing in detail the configuration of the wavelength conversion section in the pulse light generation section 20 of the light source device LSa (LSb) shown in fig. 7, fig. 19 is a diagram showing the optical path of the light beam LBa (LBb omitted) from the light source device LSa (LSb) to the first selection optical element AOM1, fig. 20 is a diagram showing the optical path from the selection optical element AOM1 to the next selection optical element AOM2 and the configuration of the driving circuit of the selection optical element AOM1, fig. 21 is a diagram showing the case of light beam selection and light beam shift in the selection mirror (branch mirror) IM1 after the selection optical element AOM1, and fig. 22 is a diagram showing the operation of the light beam from the polygon mirror PM to the substrate P.

As shown in fig. 18, the amplified seed light (light beam) Lse is emitted from the emission end 46a of the optical fiber amplifier 46 in the light source device LSa at a small divergence angle (NA: numerical aperture). The lens element GL (GLa) condenses the seed light Lse so as to become a beam waist in the 1 st wavelength conversion element (wavelength conversion optical element) 48. Therefore, the 1 st harmonic beam after the wavelength conversion by the 1 st wavelength conversion element 48 is divergently incident on the lens element GL (GLb). The lens element GLb condenses the harmonic light beam of the 1 st order so as to become a beam waist in the 2 nd wavelength conversion element (wavelength conversion optical element) 50. The 2 nd harmonic light beam after the wavelength conversion by the 2 nd wavelength conversion element 50 is incident on the lens element GL (GLc) with divergency. The lens element GLc is disposed so that the 2 nd harmonic light beam is a substantially parallel beamlets LBa (LBb) and is emitted from the emission window 20H of the light source device LSa. The diameter of the light beam LBa emitted from the emission window 20H is several mm or less, preferably about 1 mm. In this way, each of the wavelength conversion elements 48 and 50 is set so as to be optically conjugate with the emission end 46a (light emission point) of the optical fiber amplifier 46 by the lens elements GLa and GLb. Therefore, even when the direction of travel of the generated harmonic light flux is slightly inclined due to the fluctuation of the crystal characteristics of the wavelength conversion elements 48 and 50, the drift in the angular direction (azimuth) of the light flux LBa emitted from the emission window 20H can be suppressed. In fig. 18, the lens element GLc is shown separately from the emission window 20H, but the lens element GLc itself may be disposed at the position of the emission window 20H.

As shown in fig. 19, the light beam LBa emitted from the emission window 20H advances along the optical axis AXj of the expander system based on the 2 condenser lenses CD0 and CD1, is converted into a substantially parallel light beam having a reduced beam diameter of about 1/2 (about 0.5 mm), and is incident on the 1 st stage selection optical element AOM1. The light beam LBa from the emission window 20H becomes a beam waist at a condensing position Pep between the condensing lens CD0 and the condensing lens CD 1. The condenser lens CD1 is provided as the condenser lens CD1 in fig. 6 above. The deflection position Pdf (diffraction point) of the light beam in the selection optical element AOM1 is set so as to be optically conjugate with the emission window 20H by an expander system based on the condenser lenses CD0 and CD 1. The light condensing position Pep is set so as to be optically conjugate with the emission end 46a of the optical fiber optical amplifier 46 and the wavelength conversion elements 48 and 50 in fig. 18. The direction of deflection of the light beam of the optical element AOM1, that is, the diffraction direction of the light beam LB1 emitted as the 1 st diffraction light of the incident light beam LBa at the time of switching, is set to the Z direction (the direction in which the spot SP on the substrate P is shifted in the sub-scanning direction). The beam LBa of the optical element AOM1 is selected to be, for example, a parallel beam having a beam diameter of about 0.5mm, and the beam LB1 emitted as 1-time diffracted light is also selected to be a parallel beam having a beam diameter of about 0.5 mm. That is, in each of the above embodiments (including the modification examples), the light beam LBa (LBb) is converged so as to become a beam waist in the selection optical element AOM1, but in embodiment 2, the light beam LBa (LBb) passing through the selection optical element AOM1 is made to be a parallel light beam having a minute diameter.

As shown in fig. 20, the light beam LBa transmitted through the selection optical element AOM1 and the light beam LB1 deflected as 1 st-order diffracted light at the time of switching are both incident on a collimator lens CL1 (corresponding to the lens CL1 in fig. 6) arranged coaxially with the optical axis AXj. The deflection position Pdf of the selection optical element AOM1 is set to the position of the front focal point of the collimator lens CL 1. Therefore, the light beams LBa and LB1 are converged so as to become beam waists on the surface Pip of the rear focal point of the collimator lens (condenser lens) CL 1. The light beam LBa traveling along the optical axis AXj of the collimator lens CL1 is incident on the condenser lens (condenser lens) CD2 shown in fig. 6 in a divergent state from the surface Pip, is again a parallel light beam having a beam diameter of about 0.5mm, and is incident on the 2 nd stage selection optical element AOM2. The deflection position Pdf of the selection optical element AOM2 of the 2 nd stage is arranged in a conjugate relationship with the deflection position Pdf of the selection optical element AOM1 by a relay system based on the collimator lens CL1 and the condenser lens CD 2.

In embodiment 2, the selecting mirror IM1 shown in fig. 6 is disposed in the vicinity of the surface Pip between the collimator lens CL1 and the condenser lens CD 2. Since the light beams LBa and LB1 are separated in the Z direction at the surface Pip at the narrowest beam waist, the arrangement of the reflecting surface IM1a of the mirror IM1 is easy. The deflection position Pdf and the plane Pip of the selection optical element AOM1 are in a relationship between the pupil position and the image plane by the collimator lens CL1, and the central axis (principal ray) of the light beam LB1 directed to the reflection surface IM1a of the mirror IM1 by the collimator lens CL1 is parallel to the principal ray (optical axis AXj) of the light beam LBa. The light beam LB1 reflected on the reflection surface IM1a of the mirror IM1 is converted into a parallel light beam by a collimator lens CL1a equivalent to the condenser lens CD2, and is directed to a mirror M10 of the scanning unit U1 shown in fig. 5. The surface Pip is optically conjugate with the condensing position Pep by the collimator lens CL1 and the condensing lens CD1 in fig. 19. Therefore, the surface Pip is also conjugate with the emission end 46a of the optical fiber amplifier 46 and the wavelength conversion elements 48 and 50 in fig. 18. That is, the surface Pip is set to be conjugate with the output end 46a of the optical fiber amplifier 46 and the wavelength conversion elements 48 and 50 by a relay lens system composed of the lens element GLa, GLb, GLc, the condenser lenses CD0 and CD1, and the collimator lens CL 1.

The optical axis AXm of the collimator lens CL1a is set coaxially with the irradiation center line Le1 in fig. 5, and when the deflection angle of the light beam LB1 by the selection optical element AOM1 at the time of switching is a predetermined angle (reference setting angle), the center line (principal ray) of the light beam LB1 is incident on the collimator lens CL1a coaxially with the optical axis AXm. As shown in fig. 20, the reflecting surface IM1a of the mirror IM1 is set to a size that reflects only the light beam LB1 so as not to interrupt the optical path of the light beam LBa, and that is, that reliably reflects the light beam LB1 even when the light beam LB1 reaching the reflecting surface IM1a is slightly shifted in the Z direction. However, when the reflecting surface IM1a of the mirror IM1 is disposed at the position of the surface Pip, a spot where the light beam LB1 is condensed is formed on the reflecting surface IM1a, and therefore, it is preferable to dispose the mirror IM1 so that the reflecting surface IM1a is slightly offset from the position of the surface Pip in the X direction. A reflective film (dielectric multilayer film) having high ultraviolet resistance is formed on the reflective surface IM 1a.

In embodiment 2, the driving circuit 102A for providing the selection optical element AOM1 with both the switching function and the shift function of the light beam is provided in the selection element driving control unit 102 shown in fig. 9. The driving circuit 102A is constituted by: a local oscillation circuit 102A1 (VCO: voltage controlled oscillator or the like) that receives a correction signal FSS for changing the frequency of a drive signal HF1 applied to the selection optical element AOM1 from a reference frequency and generates a correction high-frequency signal corresponding to the frequency to be corrected for the reference frequency; a hybrid circuit 102A2 that combines the frequency-stabilized high-frequency signal generated by the reference oscillator 102S and the corrected high-frequency signal from the local oscillation circuit 102A1 in a frequency-added manner; and an amplifying circuit 102A3 for converting the high-frequency signal frequency-synthesized by the hybrid circuit 102A2 into a driving signal HF1 amplified to an amplitude suitable for driving the ultrasonic vibrator of the optical element AOM 1. The amplifier circuit 102A3 has a switching function of switching the high-frequency drive signal HF1 to a high level and a low level (or amplitude zero) in response to the incidence enable signal LP1 generated in the selection element drive control section 102 of fig. 9. Therefore, during the period when the drive signal HF1 is at the high level amplitude (during the period when the signal LP1 is at the H level), the optical element AOM1 is selected to deflect the light beam LBa to generate the light beam LB1. The optical system and the driving circuit 102A of the mirror IM1 and the collimator lens CL1a as in fig. 20 are provided in the same manner for the other selection optical elements AOM2 to AOM 6. In the above configuration, the local oscillation circuit 102A1 and the hybrid circuit 102A2 function as a frequency modulation circuit that varies the frequency of the drive signal HF1 according to the value of the correction signal FSS.

In the driving circuit 102A, when the correction signal FSS indicates zero correction, the frequency of the driving signal HF1 output from the amplifying circuit 102A3 is set to a predetermined frequency such that the deflection angle of the light beam LB1 based on the optical element AOM1 for selection becomes a predetermined angle (reference setting angle). When the correction signal FSS indicates the correction amount +Δfs, the frequency of the driving signal HF1 is corrected so that the deflection angle of the light beam LB1 based on the selection optical element AOM1 increases by Δθγ with respect to the predetermined angle. When the correction signal FSS indicates the correction amount Δfs, the frequency of the driving signal HF1 is corrected so that the deflection angle of the light beam LB1 based on the selection optical element AOM1 is reduced by Δθγ with respect to the predetermined angle. When the deflection angle of the light beam LB1 changes ±Δθγ with respect to the predetermined angle, the position of the light beam LB1 incident on the reflection surface IM1a of the mirror IM1 is slightly shifted in the Z direction, and the light beam LB1 (parallel light beam) emitted from the collimator lens CL1a is slightly tilted with respect to the optical axis AXm. This will be further described with reference to fig. 21.

Fig. 21 is an enlarged optical path diagram showing a case of shifting the light beam LB1 deflected by the selection optical element AOM 1. When the light beam LB1 is deflected at a predetermined angle by the selection optical element AOM1, the central axis of the light beam LB1 and the optical axis AXm of the collimator lens CL1a become coaxial. At this time, the central axis of the light beam LB1 emitted from the collimator lens CL1 is separated by Δsf0 in the-Z direction from the central axis (optical axis AXj) of the original light beam LBa. When the frequency of the drive signal HF1 for driving the selection optical element AOM1 is increased by Δfs from this state, for example, the deflection angle of the light beam LB1 reaching the mirror IM1 is increased by Δθγ with respect to a predetermined angle, and the central axis AXm 'of the light beam LB1' reaching the mirror IM1 is located at a position separated by Δsf1 in the-Z direction from the optical axis AXj. As described above, the central axis AXm 'of the light beam LB1' directed to the mirror IM1 is laterally displaced (parallel-shifted) by Δsf1 to Δsf0 in the-Z direction from the predetermined position (the position coaxial with the optical axis AXm) according to the change in Δfs of the frequency of the drive signal HF 1.

On the optical axis AXm, a surface Pip ' corresponding to the surface Pip exists, and the light beam LB1 (LB 1 ') is condensed so as to become a beam waist on the surface Pip '. The central axis AXm ' of the light beam LB1' directed from the plane Pip ' toward the collimator lens CL1a is parallel to the optical axis AXm, and the light beam LB1' emitted from the collimator lens CL1a is converted into a parallel light beam slightly inclined in the XZ plane with respect to the optical axis AXm by setting the plane Pip ' at the front focal point position of the collimator lens CL1 a. In the present embodiment, the lens system (the lenses Be1 and Be2, and the cylindrical lens CYa, CYb, f θ lens TF in fig. 5) in the scanning unit U1 is arranged so that the surface Pip' is finally conjugate with the surface (the spot SP) of the substrate P.

Fig. 22 is a view of the optical path from 1 reflection surface RP (RPa) of the polygon mirror PM in the scanning unit U1 to the substrate P, as viewed from the Yt direction. The light beam LB1 deflected at a predetermined angle by the selection optical element AOM1 is incident on the reflection surface RPa of the polygon mirror PM in a plane parallel to the XtYt plane and is reflected. The light beam LB1 incident on the reflection surface RPa is converged in the Zt direction on the reflection surface RPa by the 1 st cylindrical lens CYa shown in fig. 5 in the XtZt plane. The light beam LB1 reflected on the reflection surface RPa is deflected at a high speed in a plane parallel to the XtYt plane including the optical axis AXf of the fθ lens FT according to the rotation speed of the polygon mirror PM, and is condensed on the substrate P as a light spot SP through the fθ lens FT and the 2 nd cylindrical lens CYb. The spot SP is one-dimensionally scanned in a direction perpendicular to the paper surface in fig. 21.

On the other hand, as shown in fig. 21, the light beam LB1 'having the surface Pip' shifted laterally from the light beam LB1 by Δsf1 to Δsf0 is incident on a position slightly shifted in the Zt direction from the irradiation position of the light beam LB on the reflection surface RPa of the polygon mirror PM. Accordingly, the optical path of the light beam LB1 'reflected by the reflection surface RPa is focused on the substrate P in the form of the light spot SP' by the fθ lens FT and the 2 nd cylindrical lens CYb in the XtZt plane in a state slightly shifted from the optical path of the light beam LB 1. The reflection surface RPa of the polygon mirror PM is optically disposed on the pupil surface of the fθ lens FT, and the reflection surface RPa and the surface of the substrate P are in a conjugate relationship in the XtZt surface of fig. 22 by the effect of the surface tilt correction of the 2 cylindrical lenses CYa, CYb. Therefore, if the light beam LB1 applied to the reflecting surface RPa of the polygon mirror PM is slightly shifted in the Zt direction as the light beam LB1', the spot SP on the substrate P is shifted by Δ SFp in the sub-scanning direction as the spot SP'.

As described above, the frequency of the drive signal HF1 of the optical element AOM1 for selection is changed by ±Δfs from the predetermined frequency, whereby the spot SP can be shifted by ±Δ SFp in the sub-scanning direction. The shift amount (|Δ SFp |) is limited by the maximum range of the deflection angle of the selection optical element AOM1 itself, the size of the reflection surface IM1a of the mirror IM1, the magnification to the optical system (relay system) of the polygon mirror PM in the scanning unit U1, the width of the reflection surface Zt direction of the polygon mirror PM, the magnification from the polygon mirror PM to the substrate P (magnification of the fθ lens FT), and the like, but is set to a range of the effective size (diameter) on the substrate P of the spot SP or the pixel size (Pxy) defined on the drawing data. Of course, the shift amount may be set to be equal to or more than this. The selection optical element AOM1 and the scanning unit U1 are described, but the same applies to the other selection optical elements AOM2 to AOM6 and the scanning units U2 to U6.

As described above, in the present embodiment, the selection optical elements AOMn (AOM 1 to AOM 6) can be used for both the function of switching the light beam in response to the incidence permission signals LPn (LP 1 to LP 6) and the function of shifting the light spot SP in response to the correction signal FSS, and therefore, the configuration of the light beam transmission system (light beam switching unit BDU) for supplying the light beam to each scanning unit Un (U1 to U6) is simplified. Further, compared with the case where an acousto-optic modulator (AOM or AOD) for beam selection and displacement of the spot SP is provided for each scanning unit Un, the heat generation source can be reduced, and the temperature stability of the exposure apparatus EX can be improved. In particular, the drive circuit (102A) for driving the acoustic-optic modulator serves as a large heat source, and the drive signal HF1 is a high frequency of 50MHz or more, and is therefore disposed in the vicinity of the acoustic-optic modulator. Even if a mechanism for cooling the driving circuit (102A) is provided, if the number of the mechanisms is large, the temperature in the device is easy to rise in a short time, and the drawing accuracy may be lowered due to the fluctuation of the temperature change of the optical system (lens or mirror). Therefore, the driving circuit and the acousto-optic modulator serving as a heat source are preferably small. In the case where the deflection angle of the light beam LBn deflected as the 1 st-order diffracted light of the incident light beam LBa (LBb) is varied by the influence of the temperature change in each of the selection optical elements AOMn (AOM 1 to AOM 6), the variation in the deflection angle can be easily canceled by providing a feedback control system for adjusting the value of the correction signal FSS applied to the driving circuit 102A of fig. 20 according to the temperature change in the present embodiment.

The beam shifting function of the optical element AOMn for selection according to the present embodiment can quickly fine-adjust the position of the drawing line SLn of the spot SPn of the light beam LBn from each of the plurality of scanning units Un in the sub-scanning direction. For example, if the optical element AOM1 for selection shown in fig. 20 is controlled so as to change the correction amount based on the correction signal FSS every time the incidence permission signal LP1 becomes the H level, the drawing line SL1 can be shifted in the sub-scanning direction by the extent of the pixel size (or the size of the light spot) for each reflection surface of the polygon mirror PM, that is, for each scanning of the light spot SP. Accordingly, the inclination of each drawing line SLn is adjusted by slightly rotating each of the adjacent scanning units Un about the irradiation center axes Le1 to Le6, and the drawing magnification is corrected as in embodiment 1 above, and the drawing lines SLn are shifted in the sub-scanning direction as in embodiment 2, whereby the accuracy of bonding at the time of pattern drawing at the end portions of each drawing line SLn can be improved. In addition, when a new pattern is superimposed and drawn on the base pattern for an electronic device which has been formed on the substrate P, the accuracy of the superimposition can be improved.

In embodiment 2 above, the surface of the substrate P (where the light beam LBn is condensed as the light spot SP) and the surface Pip 'in fig. 21 are set in a conjugate relationship with each other, and the surface Pip' (Pip) is also set in a conjugate relationship with each of the wavelength conversion elements 48 and 50 in the light source device LSa (LSb) and the emission end 46a of the optical fiber amplifier 46. Therefore, when the light beam LBn is projected as the light spot SP through the fθ lens FT and the cylindrical lens CYb to the 1-point on the surface of the substrate P in a state where the 1 reflection surface of the polygon mirror PM is made stationary in a fixed direction, the light spot SP on the substrate P is kept stationary without being affected by the change in the crystal characteristics of the wavelength conversion elements 48, 50 even if the advancing direction of the harmonic light beam is angularly shifted. This means that the scanning start position of the spot SP in the main scanning direction or the drawing start position in response to the origin signal SD does not drift in the main scanning direction and remains stable. Therefore, pattern drawing can be performed with stable accuracy for a long period of time.

[ embodiment 3 ]

Fig. 23 is a view of embodiment 3 showing a specific configuration of the scanning unit U1 (Un) applied to embodiment 2 described above, and is a view obtained by observing a plane (XZ plane) orthogonal to a plane (a plane parallel to the XY plane) including the scanning direction (deflection direction) of the light beam LB 1. In fig. 23, the optical axis AXf of the fθ lens system FT is arranged parallel to the XY plane, and the front mirror M15 is arranged so as to bend the optical axis AXf by 90 degrees. In the scanning unit U1, along a light transmission path of the light beam LB1 from the incident position of the light beam LB1 to the irradiated surface (substrate P), a mirror M10, a beam expander BE, a parallel flat plate HVP with a variable inclination angle, an aperture stop PA, a mirror M12, a 1 st cylindrical lens CYa, a mirror M13, a mirror M14, a polygon mirror PM (reflection surface RP), an fθ lens system FT, a mirror M15, and a 2 nd cylindrical lens CYb are provided. The configuration of fig. 23 is basically the same as that of fig. 5, and a part of members and the like which do not need to be described are omitted. In the present embodiment, the parallel plate SR2 of the shift optical member SR provided in fig. 5 is a light-transmissive parallel plate (quartz plate) HVP.

The beam LB1 of the parallel beam reflected in the-Z direction by the mirror IM1 shown in fig. 6 is incident on the mirror M10 inclined at 45 degrees with respect to the XY plane. The mirror M10 reflects the incident light beam LB1 in the-X direction toward a mirror M12 separated in the-X direction from the mirror M10. The beam LB1 reflected by the mirror M10 is transmitted through the beam expander BE and the aperture stop PA and is incident on the mirror M12. The beam expander BE expands the diameter of the transmitted light beam LB 1. The beam expander BE has a condenser lens BE1 and a collimator lens BE2 for converging the beam LB1 diverged by the condenser lens BE1 into a parallel beam. The beam LB6 is easily irradiated to the opening portion of the aperture diaphragm PA by the beam expander BE. A parallel flat plate HVP of quartz whose inclination angle can Be changed by a driving motor or the like, not shown, is arranged between the condensing lens Be1 and the collimator lens Be2. By changing the inclination angle of the parallel flat plate HVP, the drawing line SLn, which is the scanning trajectory of the light spot SP scanned on the substrate P, can be shifted by a small amount (for example, about several times to ten times the effective size Φ of the light spot SP) in the sub-scanning direction.

The mirror M12 is disposed inclined at 45 degrees with respect to the YZ plane, and reflects the incident light beam LB1 in the-Z direction toward a mirror M13 separated in the-Z direction from the mirror M12. The light beam LB1 reflected in the-Z direction by the mirror M12 passes through the 1 st cylindrical lens CYa (1 st optical element) and reaches the mirror M13. The mirror M13 is disposed at an angle of 45 degrees with respect to the XY plane, and reflects the incident light beam LB1 toward the mirror M14 in the +x direction. The light beam LB1 reflected by the mirror M13 is reflected by the mirror M14 and then projected onto the polygon mirror PM. The 1 reflection surface RP of the polygon mirror PM reflects the incident light beam LB1 in the +x direction toward the fθ lens system FT having the optical axis AXf extending in the X-axis direction.

By changing the inclination angle of the parallel flat plate HVP provided between the lens systems BE1, BE2 constituting the beam expander BE, the drawing line SLn can BE shifted in the sub-scanning direction. Fig. 24A and 24B are diagrams for explaining a case where the drawing line SLn is shifted by the inclination of the parallel flat plate HVP, and fig. 24A is a diagram showing a state where the incident surface and the emission surface of the parallel flat plate HVP parallel to each other are 90 degrees with respect to the center line (principal ray) of the light flux LBn, that is, a diagram showing a state where the parallel flat plate HVP is not inclined in the XZ plane. Fig. 24B is a diagram showing a state in which the incident plane and the emission plane of the parallel flat plate HVP, which are parallel to each other, are inclined from 90 degrees with respect to the center line (principal ray) of the light flux LBn, that is, the parallel flat plate HVP is inclined at an angle η with respect to the YZ plane.

Further, in fig. 24A and 24B, in a state where the parallel flat plate HVP is not inclined (angle η=0 degrees), the optical axes AXe of the lens systems Be1 and Be2 are set to pass through the center of the circular opening of the aperture stop PA, and the center line of the light flux 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 stop PA. The position of the aperture stop PA is set so that the position of the 1 st cylindrical lens CYa is regarded as a substantially pupil position from the position of the reflecting surface RP of the polygon mirror PM (or the position of the front focal point of the fθ lens system FT) in the sub-scanning direction. On the other hand, in the main scanning direction, the aperture stop PA is arranged so as to be optically conjugate with the position of the front focal point of the fθ lens system FT, that is, the position of the entrance pupil. Therefore, when the parallel flat plate HVP is tilted at the angle η, the center line of the light beam LBn (here, a divergent light beam) which is incident on the lens system Be2 through the parallel flat plate HVP is slightly parallel-shifted in the-Z direction with respect to the optical axis xe, the light beam LBn which is emitted from the lens system Be2 is converted into a parallel light beam, and the center line of the light beam LBn is slightly tilted with respect to the optical axis xe.

Since 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 stop PA, the light beam LBn (parallel light beam) emitted obliquely from the lens system Be2 is continuously projected to the circular opening without being shifted in the Z direction on the aperture stop PA. Therefore, the light flux LBn having passed through the circular opening of the aperture stop PA is directed toward the 1 st cylindrical lens CYa of the rear stage at an angle slightly inclined in the sub-scanning direction in the XZ plane with respect to the optical axis xe in a state where the intensity of the basis of 1/e2 on the intensity distribution is correctly cut off. The aperture stop PA is a position on the reflecting surface RP of the polygon mirror PM at which the light beam LBn (converging in the sub-scanning direction) incident on the reflecting surface RP of the polygon mirror PM is slightly shifted in accordance with the inclination angle in the sub-scanning direction of the light beam LBn having passed through the circular opening of the aperture stop PA, corresponding to the pupil position as viewed from the reflecting surface RP of the polygon mirror PM. Therefore, the light flux LBn reflected on the reflection surface RP of the polygon mirror PM is also incident on the fθ lens system FT in a state of slightly shifting in the Z direction with respect to a plane parallel to the XY plane including the optical axis AXf of the fθ lens system FT shown in fig. 23. As a result, the light beam LBn incident on the 2 nd cylindrical lens CYb is slightly inclined in the sub-scanning direction, and the position of the spot SP of the light beam LBn projected on the substrate P can be slightly shifted in the sub-scanning direction.

[ embodiment 4 ]

Fig. 25 is a block diagram showing the configuration of the control device 16 of the exposure apparatus EX (pattern drawing apparatus) according to embodiment 4. In fig. 25, the polygon mirror drive control unit 100, the selection element drive control unit 102, the beam control unit 104 (exposure control unit 116), the mark position detection unit 106, and the rotational position detection unit 108 that constitute the control device 16 have the same configuration as shown in fig. 9. In fig. 25, the state in which the light beam LBa from the light source device LSa is supplied to the scanning unit U1 is represented only in a representative mode, the optical element AOM1 for selection, the collimator lens CL1, and the unit-side incident mirror IM1 are arranged in the same manner as in fig. 20, and the scanning unit U1 from the reflecting mirror M10 to the 2 nd cylindrical lens CYb is configured in the same manner as in fig. 23. In the present embodiment, a servo control system DU including a piezoelectric motor or the like for tilting a parallel flat plate HVP, which is a mechanical optical beam shifter, in the scanning unit U1 by a specific stroke, and a base layer measuring unit MU are provided. The underlayer measuring unit MU has a circuit configuration for rapidly and digitally sampling the waveform change of the photoelectric signal from the photodetector DT (see fig. 5) in the scanning unit U1, and measures the position in the main scanning direction or the sub-scanning direction of the base pattern or the relative position error (overlay error) between the new pattern of the overlay exposure and the base pattern based on the intensity change of the reflected light generated when the light spot SP scans the base pattern (corresponding to the metal layer, the insulating layer, the semiconductor layer, or the like) formed on the substrate P for the overlay exposure. The measurement result measured by the base layer measuring unit MU, in particular, the information on the overlay error is used to generate the correction signal FSS to be applied to the driving circuit 102A in the selection element driving control unit 102 shown in fig. 20. By providing the photodetector DT (see fig. 5) and the underlayer measuring unit MU as the position measuring unit for each of the scanning units Un in this manner, the overlay accuracy in the exposure target area (device forming area in fig. 4) W of the alignment-free mark MKn or the moving position of the substrate P during pattern exposure (moving position of the device forming area W) can be confirmed.

Since the parallel flat plate HVP is provided in each of the scanning units Un, the inclination angle η of the parallel flat plate HVP is continuously changed for each scanning unit Un, whereby the size of the pattern drawn on the substrate P in the sub-scanning direction can be expanded and contracted at a minute rate. Therefore, even when the substrate P is locally stretched in the longitudinal direction (sub-scanning direction) of the substrate P, the overlay accuracy can be maintained well when the pattern for the 2 nd layer is overlay-exposed (drawn) to the base pattern (1 st layer pattern) for the electronic device formed on the substrate P together with the alignment mark MKn. The local expansion and contraction in the longitudinal direction (sub-scanning direction) of the substrate P can be measured by detecting alignment marks MK1 and MK4 formed at both sides in the width direction of the substrate P at a fixed pitch (for example, 10 mm) in the longitudinal direction by using an alignment microscope AM1m shown in fig. 25, for example, as shown in fig. 4. Specifically, as shown in fig. 4, the alignment marks MK1 and MK4 are sequentially imaged by the imaging devices by the alignment microscopes AM11 and AM14, and the change in the longitudinal direction of the mark position (the change in the pitch of the mark, etc.) is analyzed and measured by the exposure control unit 116 by the mark position detection unit 106, the rotational position detection unit 108, etc. Accordingly, a control command is given from the exposure control unit 116 to the servo control system DU to gradually tilt the parallel flat plate HVP in accordance with the moving position (or moving amount) of the substrate P in the sub-scanning direction, based on the local expansion/contraction amount (scaling error) in the conveying direction of the substrate P. Thus, the drawing position of the pattern can be gradually adjusted in the sub-scanning direction in conjunction with the moving position of the substrate P, and the reduction in the accuracy of the overlay exposure for the substrate P having a large expansion and contraction can be suppressed.

The parallel flat panel HVP may be used to adjust the interval between the odd-numbered drawing lines SL1, SL3, and SL5 and the even-numbered drawing lines SL2, SL4, and SL6 in the sub-scanning direction (the conveyance direction of the substrate P). For example, when a moderate fluctuation in the transport speed of the substrate P occurs, the pattern drawn by the odd-numbered drawing lines and the pattern drawn by the even-numbered drawing lines are shifted in the sub-scanning direction by a micrometer scale due to the fluctuation in the transport speed, and the bonding accuracy is deteriorated. Therefore, the rotation position detecting unit 108 that counts the measurement signals from the encoders ENja and ENjb (in fig. 25, only EN1a and EN2a are representatively shown) that measure the rotation position of the rotating drum DR may detect the fluctuation of the rotation speed of the rotating drum DR (the speed fluctuation of the substrate P), and the inclination of the parallel flat plate HVP may be driven by the servo control system DU according to the increase or decrease of the fluctuation.

Further, the beam shifter (beam position adjusting means, 2 nd adjusting optical means) using the mechanical optics of the parallel plate HVP may be used for coarse adjustment of the position adjustment of the light spot SP in the sub-scanning direction, and the beam shifter (beam position adjusting means, 2 nd adjusting optical means) using the optoelectronics of the selection optical element AOM1 shown in fig. 25 (or the acousto-optic deflection element AODs shown in fig. 16, the optoelectronics ODn, KDn shown in fig. 17, or the like) may be used for fine adjustment of the position adjustment of the light spot SP in the sub-scanning direction. In the case of combining the parallel flat plate HVP with the optical element AOM1 (AOMn) for selection as shown in fig. 25, the parallel flat plate HVP as the mechanical optical beam shifter can shift the spot SP on the substrate P by several tens of pixels (for example, about ±100 μm) in the sub-scanning direction within a tiltable stroke range, and on the other hand, the optical element AOM1 (AOMn) for selection as the optical beam shifter can rapidly shift the spot SP on the substrate P in a slight range of, for example, several pixels (about several times the size Φ of the spot SP) in the sub-scanning direction.

In the photoelectric beam shifters using the selection optical elements (acousto-optic deflection elements) AOMn, AODs, photoelectric elements ODn, KDn, or the like, the position of the spot SP in the sub-scanning direction can be quickly fine-tuned for every 1 scan by changing the value of the correction signal FSS each time the incidence permission signal LPn shown in fig. 10 is generated. Therefore, the drawing quality when a fine pattern is drawn can be improved, and in particular, the bonding error when bonding the patterns drawn by the respective plurality of drawing lines SLn in the main scanning direction can be reduced. In the present embodiment, as an example, the degree of the joint error can be measured substantially in real time by using the photodetector DT and the underlayer measuring unit MU shown in fig. 25. For example, in fig. 4, when the base pattern (layer 1 pattern) is formed on the substrate P in the case where the patterns drawn by the drawing lines SL1 and SL2 are joined in the sub-scanning direction, the joining error in the sub-scanning direction of the patterns drawn by the drawing lines SL1 and SL2 based on the base pattern can be confirmed by comparing the information of the overlapping error of the joining portion measured by the base layer measuring unit MU (fig. 25) provided in the scanning unit U1 for pattern drawing with the information of the overlapping error of the joining portion measured by the same base layer measuring unit MU provided in the scanning unit U2 for pattern drawing with the drawing lines SL 2.

In the case of fig. 4, since the position in the sub-scanning direction on the substrate P drawn by the drawing line SL1 is drawn by the drawing line SL2 after the substrate P is moved by the distance between the drawing line SL1 and the drawing line SL2 in the sub-scanning direction, a time difference occurs at the time of the movement by the distance, but if the overlay error by the underlayer measuring unit MU is successively measured every appropriate movement amount of the substrate P (for example, every 1mm or every 5 mm), the tendency of the joint error (whether or not the error becomes large) can be grasped. When the tendency of the bonding error to be large is exhibited, the position of the spot SP scanned along at least one of the drawing lines SL1 and SL2 in the sub-scanning direction may be finely adjusted by adjusting the correction signal FSS applied to the driving circuit 102A (see fig. 20) in the selection element driving control unit 102 provided corresponding to at least one of the scanning unit U1 and the scanning unit U2 based on the information of the bonding error measured by the underlayer measuring unit MU so that the bonding error is reduced.

[ another modification 1 ]

In each of the above embodiments and modifications, the tiltable parallel plate Sr2 or HVP serving as the mechanical optical beam shifter (position adjusting means, 1 st adjusting means) that shifts the light beam LBn (the light spot SP) in the sub-scanning direction is provided in the optical path from the mirror M10 to the polygon mirror PM within the scanning unit Un, but may be provided in the optical path from the polygon mirror PM to the substrate P. Furthermore, the mechano-optical beam shifter may be provided in the optical path from the unit-side incident mirrors IMn (IM 1 to IM 6) of the beam switching unit BDU to the mirror M10 of the scanning unit Un. As described above, the mechanical optical beam shifter (1 st adjustment means, 1 st adjustment optical means) can shift the spot SP of the light beam LBn in the sub-scanning direction over a relatively large range, but since errors depending on mechanical accuracy are likely to remain, the photoelectric beam shifter (2 nd adjustment means, 2 nd adjustment optical means) can be used simultaneously to reduce the residual errors. In this case, the electrooptic beam shifter is preferably disposed in front of the mechano-optical beam shifter along the optical path along which the light beams LBa, LBb from the light source devices LSa, LSb travel.

[ another modification 2 ]

The lens systems BE1 and BE2 constituting the beam expander BE are arranged as convex lens systems having positive refractive power as shown in fig. 23 above in each of the scanning units (drawing units) Un, but as shown in fig. 26, the lens system BE1 on which the light beam LBn reflected by the reflecting mirror M10 is incident may BE replaced with a concave lens system BE1' having negative refractive power. Fig. 26 is a diagram schematically and greatly showing a state of a light flux LBn in the optical path from the mirror M10 to the aperture stop PA in the optical path within the scanning unit (drawing unit) Un shown in fig. 23. The light beam LBn reflected by the reflecting mirror M10 is incident on the concave lens system Be1' as a thin parallel light beam having an effective beam diameter of 1mm or less. The lens system Be1 'makes the incident light beam LBn incident on the convex lens system Be2 having positive refractive power while diverging according to the focal length of the lens system Be1'. By matching the position of the front focal length of the concave lens system Be1' with the position of the front focal length of the convex lens system Be2, the light beam LBn emitted from the convex lens system Be2 is directed to the aperture stop PA as a parallel light beam with an effective light beam diameter enlarged as illustrated in fig. 23. The beam expander using the concave lens system Be1' and the convex lens system Be2 can shorten the physical distance between 2 lens systems compared with the beam expander using 2 convex lens systems Be1, be2.

In the beam expander BE of the scanning unit (drawing unit) Un shown in fig. 23, only a parallel flat plate HVP is provided for mechanically and optically shifting the drawing line SLn, which is the scanning locus of the light spot SP, in the sub-scanning direction (X direction) on the substrate P. However, in order to finely adjust the entire drawing line SLn in the main scanning direction (Y direction), the parallel flat plate HVPx serving as the phase shifter for the X direction and the parallel flat plate HVPy serving as the phase shifter for the Y direction may Be arranged between the lens system Be1' and the lens system Be2 along the optical axis xe. In this case, the rotation center axis Sy for tilting the parallel flat plate HVPx and the rotation center axis Sx for tilting the parallel flat plate HVPy are set to be orthogonal to each other in a plane orthogonal to the optical axis AXe (parallel to the YZ plane).

[ another modification 3 ]

As shown in fig. 27, a parallel flat plate HVPy serving as a mechano-optical phase shifter for fine-adjusting the entire drawing line SLn in the main scanning direction (Y direction) may be provided after the fθ lens system FT. Fig. 27 is a diagram showing an optical system arrangement from the polygon mirror PM to the substrate P in the scanning unit (drawing unit) Un shown in fig. 23. Since the light beam LBn is scanned in the main scanning direction (Y direction) after the fθ lens system FT, when the parallel flat plate HVPy is provided between the mirror M15 and the 2 nd cylindrical lens CYb as shown in fig. 27, the parallel flat plate HVPy is set to have a length equal to the size of the cylindrical lens CYb in the Y direction. Further, a rotation center axis Sx for tilting the parallel flat plate HVPy in the plane parallel to the YZ plane in fig. 27 is set parallel to the X axis and is set so as to be orthogonal to the optical axis AXf of the fθ lens system FT which becomes parallel to the Z axis after bending the mirror M15.

Claims

1. A pattern drawing device is provided with: a rotary polygon mirror that performs one-dimensional scanning in a main scanning direction of a drawing light beam subjected to intensity modulation according to a pattern to be drawn on a substrate; and a scanning optical system for condensing the drawing beam subjected to one-dimensional scanning onto the substrate in the form of a light spot, the scanning optical system including:

a 1 st adjustment member of mechanical optics, which is arranged in an optical path of the drawing beam before being incident on the rotary polygon mirror or in an optical path of the drawing beam from the rotary polygon mirror to the substrate, and which can adjust a position of the light spot in a sub-scanning direction intersecting the main scanning direction; a kind of electronic device with high-pressure air-conditioning system

A 2 nd adjustment member of the photoelectric property, which is disposed in an optical path of the drawing beam immediately before the 1 st adjustment member, and which can adjust a position of the light spot in the sub-scanning direction;

the pattern drawing device further includes a beam expander that uses 2 lens systems that are arranged at a specific interval and expand the beam diameter of the drawing beam incident on the reflecting surface of the rotating polygon mirror in a direction corresponding to the main scanning direction, and the 1 st adjustment member is provided between the 2 lens systems;

One of the 2 lens systems is a convex lens system having a positive refractive power, and the other is a concave lens system having a negative refractive power, so that the position of the front focal distance of the concave lens system coincides with the position of the front focal distance of the convex lens system.

2. The pattern drawing device according to claim 1, wherein

The 1 st adjustment member is a tiltable transmissive parallel plate that is mechanically driven to displace the drawing light beam incident on the reflecting surface of the rotary polygon mirror in a direction corresponding to the sub-scanning direction.

3. The pattern drawing device according to claim 1 or 2, further comprising a light source device that generates the drawing light beam, and

the 2 nd adjustment member is a photoelectric phase shifter provided between the light source device and the 1 st adjustment member, and configured to shift a position of the drawing light beam incident on the reflecting surface of the rotary polygon mirror in a direction corresponding to the sub-scanning direction on the reflecting surface of the rotary polygon mirror by means of electric physical property control.

4. The pattern drawing device according to claim 3, wherein

The electro-optical phase shifter is an acousto-optic modulator or an acousto-optic deflection element capable of adjusting a deflection angle of the drawing beam according to a frequency of high-frequency power applied as a driving signal.

5. A pattern drawing method for scanning a spot of a drawing light beam projected from each of a plurality of drawing units arranged along a 1 st direction on a substrate in the 1 st direction, moving the substrate along a 2 nd direction intersecting the 1 st direction, bonding and drawing a pattern drawn by each of the plurality of drawing units in the 1 st direction, and comprising:

a measurement step of detecting a position of a reference pattern formed on the substrate during movement of the substrate, and measuring a position of an exposed region on the substrate;

a 1 st adjustment step of mechanically and optically adjusting the position of the light spot in the 2 nd direction during the movement of the substrate based on the drawing means, based on the position calculated in the measurement step; a kind of electronic device with high-pressure air-conditioning system

A 2 nd adjustment stage for adjusting the position of the light spot based on each of the drawing units to be finer in the 2 nd direction than in the 1 st adjustment stage;

The substrate is a flexible sheet substrate having a long length in the 2 nd direction, the reference pattern is a plurality of marks formed at specific design intervals along the 2 nd direction, and

the measurement step is to detect the positions of the plurality of marks on the upstream side of the drawing position of the pattern by the drawing means in the moving direction of the sheet substrate.

6. The pattern drawing method according to claim 5, wherein

The 1 st adjustment step is to adjust the position of the light spot in the 2 nd direction based on the error of the interval in the 2 nd direction of each of the plurality of marks detected in the measurement step with respect to the design interval.

7. The pattern drawing method according to claim 5 or 6, wherein

Each of the plurality of drawing units includes: a rotary polygon mirror having a plurality of reflection surfaces for reflecting the drawing light beam by changing an angle in a direction corresponding to the 1 st direction; and a scanning optical system for condensing the drawing light beam reflected by each reflecting surface of the rotating polygon mirror to a light spot on the substrate; and is also provided with

In the 1 st adjustment stage, the position of the drawing light beam projected onto each reflecting surface of the rotary polygon mirror is shifted in a direction corresponding to the 2 nd direction on the reflecting surface of the rotary polygon mirror by mechanical driving of an adjustment member.

8. The pattern drawing method according to claim 7, wherein

A base pattern is formed on the substrate,

a photodetector for detecting a change in reflected light generated when the light spot scans the base pattern while a new pattern to be subjected to overlapping exposure is being drawn on the base pattern by scanning the light spot of the drawing light beam, the photodetector being provided in each of the plurality of drawing units

In the measuring step, a joint error between the new patterns drawn by the drawing units with reference to the base pattern is measured based on the photoelectric signals from the photodetectors of the drawing units.

9. The pattern drawing method according to claim 8, wherein

The 2 nd adjustment step is to adjust the position of the light spot in the 2 nd direction so that the bonding error calculated in the measurement step is reduced.