TWI735672B - Beam scanning device, pattern drawing device, and accuracy inspection method of pattern drawing device - Google Patents

Abstract

The exposure device (EX) of the present invention projects the processing beam (LBn) to each of the multiple reflective surfaces (RP) of the polygon mirror (PM) that rotates around the rotation axis (AXp), and makes the multiple reflective surfaces The processing beam (LBn) reflected by each of (RP) passes through the fθ lens system (FT) to scan on the substrate (P). The exposure device (EX) is equipped with: an origin sensor, which generates an origin signal (SZn) whenever each of the multiple reflecting surfaces (RP) of the polygon mirror (PM) becomes a predetermined predetermined angle; and A correction part, which generates a corrected origin signal (SZn') corrected by a correction value corresponding to the time interval of the origin signal (SZn) generated corresponding to each of the plurality of reflecting surfaces (RP) The correction value of the deviation.

Description

Beam scanning device, pattern drawing device, and accuracy inspection method of pattern drawing device

The present invention relates to a beam scanning device that scans the spot light of the beam irradiated on the irradiated surface of an object, a pattern drawing device that uses this beam scanning device to draw a predetermined pattern of exposure, and a precision inspection of the pattern drawing device method.

In the past, it has been known, for example, to use the laser processing device (optical scanning device) of Japanese Patent Laid-Open No. 2005-262260 as shown below to realize the following operation, that is, to project the spot light of the laser beam to the irradiated body (processing Object), and one side uses a scanning mirror (polygon mirror) to make the spot light perform main scanning in a one-dimensional direction, and the other side moves the illuminated object in the sub-scanning direction orthogonal to the main scanning direction to be illuminated The desired pattern or image (text, graphics, etc.) is formed on the body.

Japanese Patent Laid-Open No. 2005-262260 discloses the installation of the following components: a galvanometer mirror that reflects the laser light from the oscillator 1 and irradiates the laser light to the workpiece at the position where the laser light is irradiated on the workpiece Correction is performed in the Y direction (sub-scanning direction); a polygon mirror, which reflects the laser light reflected by the galvanometer mirror and makes it scan in the X direction (main scanning direction) on the workpiece; fθ lens, which makes The laser light reflected by the galvanometer mirror is condensed on the workpiece; and the control unit, which deals with the distortion aberration generated when the laser light passes through the fθ lens, to correct the Y-direction irradiation position of the laser light on the workpiece The error method controls the reflection angle of the galvanometer mirror, and the pulse oscillation interval of the laser light generated by the oscillator is controlled by the method of correcting the irradiation position error of the laser light on the workpiece in the X direction. Furthermore, in Figure 8 of Japanese Patent Application Publication No. 2005-262260, it is shown that a laser light source and a detector are installed, and based on the end detection signal, the oscillator is controlled as shown in Figure 9 of Japanese Patent Application Publication No. 2005-262260. The structure of the timing of pulse oscillation, the laser light source emits the detection laser light used to detect the end of each reflecting surface of the polygon mirror during the rotation of the polygon mirror, and the detector is reflected by the end of each reflecting surface of the polygon mirror It detects the reflected light of the laser light and generates an end detection signal. Regarding the laser processing device (beam scanning device) using a polygon mirror as in Japanese Patent Laid-Open No. 2005-262260, the higher the rotation of the polygon mirror, the more the processing time of the processed object can be shortened. Improve productivity. However, there are cases where the higher the rotation speed of the polygon mirror, the more obvious the deviation of the processing position in the main scanning direction.

The first aspect of the present invention is a beam scanning device that projects a processing beam to each of a plurality of reflective surfaces of a rotating polygon mirror that rotates around a rotation axis, so that the beam is reflected by each of the plurality of reflective surfaces The processing beam passes through the scanning optical system to scan on the irradiated body, and is equipped with an origin detection unit, which generates an origin every time each of the plural reflecting surfaces of the rotating polygon mirror becomes a predetermined predetermined angle Signal; and a correction part, which generates a corrected origin signal corrected by a correction value corresponding to the amount of deviation of the time interval of the origin signal generated according to each of the plurality of reflecting surfaces value.

The second aspect of the present invention is a pattern drawing device, which projects a drawing light beam to each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, and is reflected by each of the plurality of reflecting surfaces The drawing beam passes through the scanning optical system to scan on the irradiated body, and the pattern is drawn on the irradiated body. The origin signal is generated when each becomes a predetermined predetermined angle; the drawing control unit sets a predetermined delay time from the generation of the origin signal as the start time point of pattern drawing by the drawing light beam; and correction Section, which corrects the delay time set by the drawing control section for each of the plurality of reflecting surfaces based on the correction value corresponding to the deviation of the time interval at which each of the plurality of reflecting surfaces becomes the predetermined angle.

The third aspect of the present invention is a pattern drawing device, which projects a drawing light beam to each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, so as to be reflected by each of the plurality of reflecting surfaces The drawing light beam passes through the scanning optical system to scan on the substrate supported by the supporting member, and the pattern is drawn on the substrate, and it is equipped with an origin detection unit, which is installed every time the plurality of reflecting surfaces of the rotating polygon mirror The origin signal is generated when each of them becomes a predetermined predetermined angle; the drawing control unit sets a predetermined delay time from the generation of the origin signal to the start time point of the pattern drawing performed by the drawing beam; correction; Section, which corrects the delay time set by the drawing control section for each of the plurality of reflecting surfaces based on the correction value corresponding to the deviation of the time interval at which each of the plurality of reflecting surfaces becomes the prescribed angle; and The measuring part measures the time between the generation time point of the reflected light generated from the reference pattern and the generation time point of the origin signal when the reference pattern formed on the support member or the substrate is scanned with the drawing beam Time, and find the correction value corresponding to the deviation.

The fourth aspect of the present invention is a pattern drawing device, which projects a drawing light beam to each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, so as to be reflected by each of the plurality of reflecting surfaces The drawing light beam passes through the scanning optical system to scan on the substrate supported by the supporting member, and the pattern is drawn on the substrate, and it is equipped with an origin detection unit, which is installed every time the plurality of reflecting surfaces of the rotating polygon mirror The origin signal is generated when each of them becomes a predetermined predetermined angle; the drawing control unit sets a predetermined delay time from the generation of the origin signal to the start time point of the pattern drawing performed by the drawing beam; correction; Section, which corrects the delay time set by the drawing control section for each of the plurality of reflecting surfaces based on the correction value corresponding to the deviation of the time interval at which each of the plurality of reflecting surfaces becomes the prescribed angle; and The measuring part has a photoelectric conversion element arranged on a part of the supporting surface of the supporting member, and measures the time point of generation of the photoelectric signal obtained when the photoelectric conversion element is scanned by the drawing beam and the origin signal The time between the generation time points is calculated, and the correction value corresponding to the deviation is obtained.

The fifth aspect of the present invention is a method for inspecting the accuracy of a pattern drawing device that projects a drawing beam to each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, so that the pattern drawing device is The drawing light beam reflected by each of the reflective surfaces passes through the scanning optical system and condenses into spot light on the substrate supported by the supporting member, and scans in the main scanning direction. The method includes the following stages: setting stage, response Generated when each of the plurality of reflecting surfaces of the rotating polygon mirror becomes a predetermined predetermined angle, in the origin signal generated from the origin detection unit, the specific reflecting surface of the rotating polygon mirror becomes the predetermined angle The specific origin signal is drawn by scanning the main scanning direction of the spot light by using the specific reflecting surface to draw the inspection pattern; the drawing stage is repeatedly generated by the rotation of the rotating polygon mirror During the interval time of the specific origin signal, while the substrate is moved in the sub-scanning direction crossing the main scanning direction by a distance smaller than the size of the spot light, the inspection pattern is drawn on the same side; the stage is repeated to make The specific reflecting surface of the rotating polygon mirror is different, the setting stage and the drawing stage are repeated; and the inspection stage is to measure the deviation of the shape of the inspection pattern drawn on the substrate or the configuration of the main scanning direction to inspect The accuracy of the origin signal.

50J‧‧‧Opening

60a‧‧‧Beam delivery part (beam delivery system)

60b‧‧‧Beam receiving part (beam receiving system)

200‧‧‧Drawing control device

210‧‧‧Counting circuit

212‧‧‧Shift register

212A‧‧‧register

214‧‧‧Shifter control circuit

220‧‧‧Sensor

222‧‧‧Detection circuit

240‧‧‧A/D conversion section

241‧‧‧Multiplier

242‧‧‧Waveform memory (memory)

244‧‧‧Address Generation Department

246‧‧‧Waveform Analysis Department

Aw‧‧‧Arrow

AX1, AXb, AXf‧‧‧Optical axis

AXo‧‧‧Central axis

AXp‧‧‧Rotation axis

Axv‧‧‧Detection area

Bga‧‧‧Laser beam (beam)

Bgb, Bgb'‧‧‧reflected beam

Bgc, Bgd, LB, LB1~LB6, LBn‧‧‧Beam

BS1‧‧‧Polarization beam splitter

CCK, CLK‧‧‧clock signal

CLK2‧‧‧Sampling clock signal

CTu‧‧‧Average position

CYa‧‧‧The first cylindrical lens

CYb‧‧‧The second cylindrical lens

DF1~DF6, DFn‧‧‧Drive signal

DR‧‧‧Rotating drum

DTc‧‧‧Photodetector

DTo‧‧‧Photoelectric conversion element

DXa, DXb‧‧‧Pattern detector

Ef, Et‧‧‧Edge

EX‧‧‧Exposure device (pattern drawing device)

Fgs、fo‧‧‧focus distance

FT‧‧‧fθ lens system (scanning lens for drawing)

Ga‧‧‧Condenser lens

Gb, Gc‧‧‧collimating lens

GLa, GLb‧‧‧lens system

GSa, GSb‧‧‧Gap Sensor (Linear Sensor)

IC1, IC2‧‧‧Current Amplifier

IC3‧‧‧Comparator section

IMn、IM1~IM6‧‧‧Entrance mirror

LBnz‧‧‧0 times beam

Lcc‧‧‧Straight

LDo‧‧‧Semiconductor laser light source

LS‧‧‧Light source device (pulse light source device)

M1~M12, M20~M24, M20a, MRa‧‧‧Mirror

Mcc‧‧‧Rotating fiducial mark

MPa~MPh‧‧‧line

OS1~OS6, OSn‧‧‧Optical components for selection

P‧‧‧Substrate (irradiated body)

PD1, PD2‧‧‧Light-receiving surface

PM‧‧‧Polygon mirror

Ps‧‧‧face

PTL1, PTL2, PTL3‧‧‧reference pattern

RM‧‧‧Rotating Motor

RP, RPa~RPh, RPa'‧‧‧Reflecting surface

RPa/b~RPh/a‧‧‧The position between the reflecting surfaces

RST‧‧‧Reset signal

SDn‧‧‧Drawing data

Sff‧‧‧shift signal

SJ‧‧‧Control Information

Sj‧‧‧Rotating pulse signal

SL1~SL6, SLn‧‧‧Drawing line

SP, SPr‧‧‧point light

STa, STb‧‧‧output signal

Sv‧‧‧signal (photoelectric signal)

SZ1~SZ6, SZn, SZn', SZn(a)1~SZn(a)7‧‧‧origin signal

Tab, Tbc, Tcd, Tde, Tef, Tfg, Tgh, Tha‧‧‧Interval time

TD, △TD, △Toa, △Tob, △Toc, △Tod, △Toe, △Tof, △Tog, △Toh, △Tu‧‧‧ Delay time

TDa~TDh‧‧‧Rotation time

Tog, Tog', Tog1, Tog2‧‧‧origin time

Tpt‧‧‧Test pattern

TR‧‧‧Absorber

Tsr'‧‧‧base time

Tu1, Tu2‧‧‧Time

U1~U6, Un‧‧‧Drawing unit

Vref‧‧‧Offset voltage (reference voltage)

X, Y, Z‧‧‧direction

△Te‧‧‧Tolerance

△Tm1~△Tm7、△Tma~△Tmh‧‧‧Origin interval time

△TPc‧‧‧Time

θf‧‧‧Angle range

Fig. 1 is a perspective view showing a schematic configuration of an exposure apparatus that performs exposure processing on a substrate of the first embodiment.

Fig. 2 is a detailed configuration diagram of the drawing unit shown in Fig. 1.

FIG. 3 is a diagram obtained by observing the configuration of the polygon mirror, fθ lens system, and the light beam receiving system constituting the origin sensor in the drawing unit shown in FIG. 2 in the XY plane.

Fig. 4 is a simplified diagram showing the configuration of the beam transmitting system and the beam receiving system shown in Figs. 2 and 3.

FIG. 5 is a diagram showing the detailed structure of the photoelectric conversion element shown in FIG. 3 or FIG. 4.

Fig. 6 is a diagram showing a schematic configuration of a light beam switching unit including a selective optical element for selectively distributing the light beam from the light source device to any one of the six drawing units.

Fig. 7 is a diagram showing the specific configuration around the optical element for selection and the incident mirror.

FIG. 8 is a top view of the 8-sided polygon mirror shown in FIG. 3 or FIG. 4. FIG.

FIG. 9 is a diagram illustrating a method of measuring the reproducibility (deviation) of the generation timing of the origin signal.

FIG. 10 is a diagram schematically showing a method of predicting the amount of time error caused by the speed variation of the polygon mirror.

FIG. 11 is a graph showing the results obtained by using the method shown in FIG. 9 to measure the reproducibility of the origin signal corresponding to each of the reflecting surfaces of the polygon mirror under the predetermined conditions.

FIG. 12 is a diagram showing the results obtained by using the method shown in FIG. 9 to measure the reproducibility of the origin signal corresponding to each of the reflecting surfaces of the polygon mirror under conditions different from those in FIG. 11.

13 is a diagram showing a state in which an average of 2 pulses per pixel of spot light is overlapped in the main scanning direction and the sub-scanning direction with 1/2 of the spot size, and a continuous pattern of 5 pixels is drawn in the main scanning direction. .

FIG. 14 is a diagram schematically showing the characteristics of the actual measurement example in FIG. 12.

FIG. 15 is a timing diagram illustrating the generation state of the origin signal (corrected origin signal) obtained by correcting the origin signal.

16 is a diagram showing an example of the configuration of a correction circuit (correction unit) that inputs the origin signal from the photoelectric conversion element and generates a corrected origin signal (correction origin signal) as shown in FIG. 15.

FIG. 17 is a diagram showing the structure of the origin sensor of Modification Example 2. FIG.

18 is a diagram showing an example of the waveform of the photoelectric signal generated from the photodetector when the line and gap-like reference patterns formed on the outer circumferential surface of the rotating cylinder are scanned by spot light.

Fig. 19 is a diagram showing an example of the circuit configuration for digitally sampling the waveform of the signal from the photodetector.

FIG. 20 is a timing diagram showing an example of the deviation of the generation timing of the corrected origin signal or the origin time of the origin signal measured by using the circuit configuration of FIG. 19.

FIG. 21 is a diagram illustrating a test exposure method used to verify the accuracy of the corrected origin signal (or the origin signal before correction) of the third embodiment.

Fig. 22 is a diagram in which a linear reference pattern continuous in the circumferential direction is provided at the end of the outer circumferential surface of the rotating cylinder in the direction in which the central axis extends.

Fig. 23 is a view showing a partial cross-section of the rotating drum DR of the fourth embodiment.

With regard to the beam scanning device, the pattern drawing device, and the accuracy inspection method of the pattern drawing device of the aspect of the present invention, preferred embodiments are given, and the accompanying drawings are referred to and the following description is given in detail. Furthermore, the aspects of the present invention are not limited to these embodiments, and include those with various changes or improvements added. That is, the constituent elements described below include those that can be easily assumed by the manufacturer and those that are substantially the same, and the constituent elements described below can be appropriately combined. In addition, various omissions, substitutions, or changes of constituent elements can be made without departing from the spirit of the present invention.

[First Embodiment]

FIG. 1 is a perspective view showing a schematic configuration of an exposure device (pattern drawing device) EX that performs exposure processing on a substrate (irradiated body) P of the first embodiment. Furthermore, in the following description, unless otherwise specified, an XYZ orthogonal coordinate system with the direction of gravity as the Z direction is set, and the X direction, Y direction, and Z direction are described according to the arrows shown in the figure.

The exposure apparatus EX is a substrate processing apparatus used in a component manufacturing system that performs predetermined processing (exposure processing, etc.) on the substrate P to manufacture electronic components. The device manufacturing system is, for example, a manufacturing system constructed with a production line for manufacturing flexible displays as electronic components, film-shaped touch panels, film-shaped color filters for liquid crystal display panels, flexible wiring, or soft sensors. Hereinafter, the description will be made on the premise of a flexible display as an electronic component. As the flexible display, there are, for example, an organic EL display, a liquid crystal display, and the like. The component manufacturing system has a so-called roll-to-roll (Roll To Roll) production method, that is, a supply roll (not shown) that rolls a soft (flexible) sheet substrate (sheet substrate) P into a roll. After the substrate P is sent out, and various treatments are continuously performed on the sent substrate P, the substrate P after various treatments is taken up by a recovery roller (not shown). Therefore, the substrate P after various treatments becomes a substrate for multiple chamfering in which a plurality of elements (display panels) are arranged in a state connected in the conveying direction of the substrate P. The substrate P conveyed from the supply roller sequentially passes through the process device of the previous step, the exposure device EX, and the process device of the subsequent step to be subjected to various processes, and is taken up by the recovery roller. The substrate P has a strip shape in which the moving direction (conveying direction) of the substrate P becomes the long side direction (long direction), and the width direction becomes the short side direction (short direction).

The substrate P uses, for example, a resin film, or a foil made of metal or alloy such as stainless steel. As the material of the resin film, for example, polyethylene resins, polypropylene resins, polyester resins, ethylene-vinyl ester copolymer resins, polyvinyl chloride resins, cellulose resins, polyamide resins, and polyimide resins can also be used. , At least one of polycarbonate resin, polystyrene resin, and vinyl acetate resin. In addition, the thickness or rigidity (Young's modulus) of the substrate P should be such that the substrate P does not produce creases or irreversible wrinkles caused by buckling when passing through the transport path of the component manufacturing system or the exposure device EX. Can. As the base material of the substrate P, a film such as PET (polyethylene terephthalate) or PEN (polyethylene naphthalate) with a thickness of about 25 μm to 200 μm is representative of the preferred sheet substrate.

The substrate P is subject to heat during various processes implemented in the device manufacturing system, so it is preferable to select a substrate P made of a material with a low thermal expansion coefficient. For example, the thermal expansion coefficient can be suppressed by mixing an inorganic filler in the resin film. The inorganic filler may also be, for example, titanium oxide, zinc oxide, aluminum oxide, or silicon oxide. In addition, the substrate P may be a single layer body of ultra-thin glass with a thickness of about 100 μm manufactured by a float method or the like, or may be a laminate body formed by bonding the above-mentioned resin film, foil, etc., to the ultra-thin glass.

In addition, the so-called flexibility of the substrate P refers to the property that the substrate P can be bent without shearing or breaking even if a force of its own weight is applied to the substrate P. In addition, the nature of buckling due to the force of its own weight is also included in flexibility. In addition, the degree of flexibility varies depending on the material, size, thickness, layer structure of the film formed on the substrate P, temperature, humidity, and other environments. In short, as long as the substrate P is correctly wound around the various conveying rollers, rotating drums and other conveying direction switching members installed in the conveying path of the component manufacturing system (exposure apparatus EX), the substrate P can be wound without buckling The smooth transfer of the substrate P with creases or breakages (cracks or cracks) can be referred to as the range of flexibility.

The process device of the previous step (including a single processing unit or a plurality of processing units) transports the substrate P sent from the supply roller toward the exposure device EX at a predetermined speed along the longitudinal direction, and the other side is transported to the exposure device EX The substrate P is processed in the previous step. Through the processing of this previous step, the substrate P conveyed to the exposure apparatus EX becomes a substrate (photosensitive substrate) on which a photosensitive functional layer (photosensitive layer) is formed.

The photosensitive functional layer becomes a layer (film) by coating it on the substrate P in the form of a solution and drying. The representative of the photosensitive functional layer is photoresist (liquid or dry film), but as a material that does not require development treatment, the lyophilic/liquid-repellent part of the photosensitive silane couple that is irradiated by ultraviolet rays is modified Mixture (SAM), or a photosensitive reducing agent that exposes a plating reducing group on the part irradiated by ultraviolet rays. In the case of using a photosensitive silane coupling agent as the photosensitive functional layer, the ultraviolet-exposed pattern on the substrate P is transformed from liquid repellency to lyophilicity. Therefore, by selectively applying a liquid containing conductive ink (an ink containing conductive nanoparticles such as silver or copper) or a semiconductor material on the lyophilic part, it can be formed into a thin film transistor (TFT). Pattern layer for electrodes, semiconductors, insulation or connection wiring. In the case of using a photosensitive reducing agent as the photosensitive functional layer, the ultraviolet-exposed pattern on the substrate P reveals the plating reducing base. Therefore, after exposure, the substrate P is directly immersed in a plating solution containing palladium ions or the like for a fixed period of time, thereby forming (precipitating) a patterned layer of palladium. This plating process is an additive process, but in addition, it can also be used as a prerequisite for the etching process of a subtractive process. In this case, the substrate P sent to the exposure device EX is preferably made of PET or PEN as the base material, and a metallic thin film such as aluminum (Al) or copper (Cu) is vapor-deposited on the entire surface or selectively , And then laminated a photoresist layer on it.

Exposure device (processing device) EX is a process device (including a single processing section or multiple processing sections) that transports the substrate P transported from the process device of the previous step at a predetermined speed, and the substrate P is transported at the same time. Processing device for exposure processing. The exposure device EX irradiates the surface of the substrate P (the surface of the photosensitive functional layer, that is, the photosensitive surface) with a light pattern corresponding to the pattern for the electronic component (for example, the pattern of the electrode or wiring of the TFT constituting the electronic component). Thereby, a latent image (modified part) corresponding to the above-mentioned pattern is formed on the photosensitive functional layer.

In this embodiment, the exposure device EX is a direct-drawing method exposure device that does not use a mask as shown in FIG. 1, that is, a so-called spot scanning method exposure device (drawing device). The exposure device EX is equipped with: a rotating drum DR, which supports the substrate P for sub-scanning and conveys it in the longitudinal direction; and a plurality of (here, 6) drawing units Un (U1~U6), etc. Pattern exposure is performed on each part of the substrate P supported by the rotating drum DR in the shape of a cylindrical surface; each of the plurality of drawing units Un (U1~U6) uses a pulsed light beam LB (pulse beam) for exposure on one side The spot light SP is scanned one-dimensionally (main scanning) on the illuminated surface (photosensitive surface) of the substrate P in the predetermined scanning direction (Y direction) using a polygonal mirror (scanning member), and one side is scanned according to the pattern data (drawing data). , Pattern information) High-speed modulation (on/off) of the intensity of the spot light SP. Thereby, a light pattern corresponding to a predetermined pattern of electronic components, circuits, wirings, etc., is drawn and exposed on the illuminated surface of the substrate P. That is, using the sub-scanning of the substrate P and the main scanning of the spot light SP, the spot light SP is relatively two-dimensionally scanned on the illuminated surface of the substrate P (the surface of the photosensitive functional layer), and the spot light SP is scanned on the illuminated surface of the substrate P. Describe the pattern of exposure established. In addition, since the substrate P is transported in the longitudinal direction, the exposed regions of the pattern exposed by the exposure device EX are provided at a predetermined interval along the longitudinal direction of the substrate P and are provided in plural. Since electronic components are formed in the exposed area, the exposed area is also an element formation area.

As shown in FIG. 1, the rotating drum DR has a central axis AXo extending in the Y direction and extending in a direction crossing the direction in which gravity acts, and a cylindrical outer peripheral surface having a fixed radius from the central axis AXo. The rotating drum DR supports (holds) a part of the substrate P in the shape of a cylindrical surface along the outer peripheral surface (circumferential surface) in the longitudinal direction, and rotates around the central axis AXo to extend the substrate P. Convey in the same direction. The rotating drum DR is supported by its outer peripheral surface on the area (part) on the substrate P on which the light beam LB (point light SP) from each of the plurality of drawing units Un (U1 to U6) is projected. The rotating drum DR supports (holds in close contact) the substrate P from the surface (rear surface) opposite to the surface on which the electronic component is formed (the surface on which the photosensitive surface is formed). Furthermore, on both sides of the Y direction of the rotating drum DR, there are provided shafts (not shown) supported by bearings in such a way that the rotating drum DR rotates around the central axis AXo. A rotation torque from a rotation drive source (for example, a motor or a deceleration mechanism, etc.) not shown in the figure is applied to the shaft, and the rotating drum DR rotates at a fixed rotation speed around the central axis AXo.

The light source device (pulse light source device) LS generates and emits a pulsed light beam (pulse light beam, pulse light, laser) LB. The light beam LB is ultraviolet light having sensitivity to the photosensitive layer of the substrate P and having a peak wavelength in the wavelength band below 370 nm. The light source device LS emits and emits a pulsed light beam LB at a frequency (oscillation frequency, predetermined frequency) Fa under the control of a drawing control device not shown in the text. The light source device LS is set as a fiber-amplified laser light source, which is composed of a semiconductor laser element that generates pulsed light in the infrared wavelength region, an optical fiber amplifier, and converts the amplified pulsed light in the infrared wavelength region into pulses in the ultraviolet wavelength region Light wavelength conversion element (harmonic generation element) and other components. By configuring the light source device LS in this way, it is possible to obtain high-brightness ultraviolet pulse light with an oscillation frequency Fa of several hundred MHz and a light emission time of one pulse light of several tens of picoseconds or less. Furthermore, the light beam LB emitted from the light source device LS becomes a relatively thin parallel light beam with a beam diameter of about 1 mm or less. Regarding the configuration that the light source device LS is set as a fiber-amplified laser light source and the pulse of the light beam LB is turned on/off at a high speed according to the state of the pixels constituting the drawing data (the logical value is "0" or "1") , Disclosed in International Public Bulletin No. 2015/166910.

The light beam LB emitted from the light source device LS is selectively (selectively) supplied to each of the drawing units Un (U1~U6) through the beam switching part, which is used as a selection of a plurality of switching elements The optical element OSn (OS1~OS6), a plurality of reflecting mirrors M1~M12, a plurality of incident mirrors IMn (IM1~IM6), and an absorber TR are composed. The optical element OSn (OS1~OS6) for selection is transparent to the light beam LB, and is composed of an acousto-optic modulator (AOM: Acousto-Optic Modulator), which is driven by an ultrasonic signal to make the incident light The primary diffracted light of the light beam LB is deflected and emitted at a predetermined angle. The plural optical elements OSn for selection and the plural incident mirrors IMn are provided corresponding to each of the plural drawing units Un. For example, the selection optical element OS1 and the incident mirror IM1 are provided corresponding to the drawing unit U1, and similarly, the selection optical elements OS2 to OS6 and the incident mirror IM2 to IM6 are provided corresponding to the drawing units U2 to U6, respectively.

From the light source device LS, the light beam LB is guided to the absorber TR by bending its optical path in a zigzag shape by the mirrors M1 to M12. Hereinafter, it will be described in detail when the optical elements OSn (OS1~OS6) for selection are all in an off state (a state where ultrasonic signals are not applied and no primary diffracted light is generated). In addition, although illustration is omitted in FIG. 1, a plurality of lenses are provided in the light beam path from the mirror M1 to the absorber TR. The plurality of lenses converge the light beam LB from the parallel light beam or diverge after converging. The beam LB is restored to a parallel beam. This structure will be explained using FIG. 4 below.

In FIG. 1, the light beam LB from the light source device LS travels in the -X direction parallel to the X axis and is incident on the mirror M1. The light beam LB reflected in the -Y direction by the mirror M1 is incident on the mirror M2. The light beam LB reflected in the +X direction by the mirror M2 directly passes through the selection optical element OS5 and reaches the mirror M3. The light beam LB reflected in the -Y direction by the mirror M3 is incident on the mirror M4. The light beam LB reflected in the -X direction by the mirror M4 directly passes through the selection optical element OS6 and reaches the mirror M5. The light beam LB reflected in the -Y direction by the mirror M5 is incident on the mirror M6. The light beam LB reflected in the +X direction by the mirror M6 directly passes through the selection optical element OS3 and reaches the mirror M7. The light beam LB reflected in the -Y direction by the mirror M7 is incident on the mirror M8. The light beam LB reflected in the -X direction by the mirror M8 directly passes through the selection optical element OS4 and reaches the mirror M9. The light beam LB reflected in the -Y direction by the mirror M9 is incident on the mirror M10. The light beam LB reflected in the +X direction by the mirror M10 directly passes through the selection optical element OS1 and reaches the mirror M11. The light beam LB reflected in the -Y direction by the mirror M11 is incident on the mirror M12. The light beam LB reflected in the -X direction by the mirror M12 directly passes through the selection optical element OS2 and is guided to the absorber TR. The absorber TR is a light trap that absorbs the light beam LB in order to suppress the leakage of the light beam LB to the outside.

Each optical element OSn for selection is a primary winding obtained by diffracting the incident light beam (zero-order light) LB at a diffraction angle corresponding to the high-frequency frequency when an ultrasonic signal (high-frequency signal) is applied. The emitted light is an emitted light beam (light beam LBn). Therefore, the light beam emitted from the optical element for selection OS1 as the primary diffracted light becomes LB1, and similarly, the light beam emitted from the optical element for selection OS2 to OS6 as the primary diffracted light becomes LB2 to LB6. In this way, each optical element OSn (OS1 to OS6) for selection functions to deflect the optical path of the light beam LB from the light source device LS. However, since the actual acousto-optic modulating element generates about 80% of the first-order diffracted light, the light beam LBn (LB1~LB6) deflected by selecting each of the optical elements OSn is better than the original one. The intensity of the light beam LB decreases. In addition, in this embodiment, the selected one of the optical elements OSn (OS1 to OS6) for selection is controlled by a drawing control device not shown in such a way that the selected one is turned on for only a fixed time. When the one selected optical element OSn for selection is in the ON state, about 20% of the zero-order light traveling straight without being diffracted by the optical element OSn for selection remains about 20%, but it is eventually absorbed by the absorber TR.

Each of the optical elements OSn for selection is set in such a way that the light beams LBn (LB1 to LB6) as the deflected primary diffracted light are deflected in the -Z direction with respect to the incident light beam LB. The light beams LBn (LB1~LB6) deflected and emitted by each of the selection optical elements OSn are projected to the incident mirror IMn (IM1~IM6) which is provided at a position separated from each of the selection optical elements OSn by a predetermined distance. ). Each incident mirror IMn guides the light beam LBn (LB1~LB6) to the corresponding drawing unit Un (U1~U6) by reflecting the incident light beam LBn (LB1~LB6) in the -Z direction.

It is also possible to use those having the same configuration, function, and function of each optical element OSn for selection. Each of the plurality of optical elements OSn for selection is turned on/off according to the on/off of the driving signal (ultrasonic signal) from the drawing control device, which turns on/off the generated diffracted light that is diffracted by the incident light beam LB. For example, when the optical element OS5 for selection is in an off state without applying a driving signal (high-frequency signal) from the drawing control device, it transmits the incident light beam LB from the light source device LS without being diffracted. Therefore, the light beam LB transmitted through the optical element OS5 for selection enters the mirror M3. On the other hand, when the optical element OS5 for selection is in the ON state, the incident light beam LB is diffracted and directed toward the incident mirror IM5. That is, the switching (beam selection) operation performed by the selection optical element OS5 is controlled based on the on/off of the drive signal. In this way, by the switching operation of each optical element OSn for selection, the light beam LB from the light source device LS can be guided to any drawing unit Un, and the drawing unit Un into which the light beam LBn is incident can be switched. In this way, regarding the configuration in which a plurality of optical elements OSn for selection are arranged in series (tandem) with respect to the light beam LB from the light source device LS, and the light beam LBn is supplied to the corresponding drawing unit Un in a time-division manner, it is disclosed in International Publication No. 2015/ No. 166910.

The order in which the optical elements OSn (OS1~OS6) for selection constituting the light beam switching unit are turned on at a fixed time is predetermined, for example, OS1→OS2→OS3→OS4→OS5→OS6→OS1→…. The sequence is determined according to the sequence of the start sequence of scanning with spot light set for each of the drawing units Un (U1~U6). That is, in this embodiment, the rotation speeds of the polygon mirrors provided in each of the six drawing units U1 to U6 are synchronized, and the phases of the rotation angles are also synchronized, whereby any one of the drawing units U1 to U6 is synchronized. One reflecting surface of the polygon mirror can be switched in a time-sharing manner by performing a spot scan on the substrate P. Therefore, as long as the phases of the rotation angles of the polygon mirrors of the drawing unit Un are synchronized with a predetermined relationship, the order of the light spot scanning of the drawing unit Un can be arbitrary. In the configuration of FIG. 1, on the upstream side of the conveying direction of the substrate P (the direction in which the outer peripheral surface of the rotating drum DR moves in the circumferential direction), three drawing units U1, U3, and U5 are arranged side by side in the Y direction. On the downstream side of the conveyance direction of the substrate P, three drawing units U2, U4, and U6 are arranged side by side in the Y direction.

In this case, the pattern drawing on the substrate P starts from the odd-numbered drawing units U1, U3, U5 on the upstream side, and after the substrate P is transported for a fixed length, the even-numbered drawing units U2, U4, U6 on the downstream side The pattern drawing is also started, so the order of the light spot scanning of the drawing unit Un can be set as U1→U3→U5→U2→U4→U6→U1→.... Therefore, the order in which each of the selection optical elements OSn (OS1~OS6) is turned on at a fixed time is determined as OS1→OS3→OS5→OS2→OS4→OS6→OS1→…. Furthermore, even in the sequence in which the selection optical element OSn corresponding to the drawing unit Un with no pattern to be drawn is turned on, the selection optical element OSn can be switched on/off according to the drawing data. By this control, it can be forcibly maintained in the off state, so that the light spot scanning using the drawing unit Un is not performed.

As shown in FIG. 1, each of the drawing units U1 to U6 is provided with a polygon mirror PM for main scanning of the incident light beams LB1 to LB6. In this embodiment, each of the polygon mirrors PM of each drawing unit Un is synchronously controlled in such a way that one side precisely rotates at the same rotation speed, and the other side maintains a fixed rotation angle phase with each other. Thereby, the main scanning timing of each of the light beams LB1 to LB6 projected from each of the drawing units U1 to U6 to the substrate P (the main scanning period of the spot light SP) can be set in a manner that does not overlap each other. Therefore, by synchronously controlling the on/off switching of each of the selection optical elements OSn (OS1~OS6) provided in the beam switching part with the rotation angle position of each of the 6 polygon mirrors PM, it can be realized An efficient exposure process for distributing the light beam LB from the light source device LS to each of the plurality of drawing units Un in a time-sharing manner.

The synchronization control of the phase alignment of the rotation angle of each of the 6 polygon mirrors PM and the on/off switching timing of each of the selection optical elements OSn (OS1~OS6) is disclosed in International Publication No. 2015 In No. /166910, in the case of 8-sided polygon mirror PM, the scanning efficiency is because about 1/3 of the rotation angle (45 degrees) corresponding to one reflecting surface corresponds to the point light on the drawing line SLn. One scan of SP, therefore, the switching of ON/OFF of each of the selection optical elements OSn (OS1~OS6) is controlled in the following way, that is, the 6 polygon mirrors PM are relatively shifted in the phase of the rotation angle. It is moved 15 degrees and rotated, and 8 reflecting surfaces of each polygon mirror PM are skipped over one surface to scan the light beam LBn. In this way, the drawing method used to skip the reflective surface of the polygon mirror PM is also disclosed in International Publication No. 2015/166910.

As shown in Fig. 1, the exposure apparatus EX adopts a so-called multi-head type direct drawing exposure method in which a plurality of drawing units Un (U1 to U6) of the same configuration are arranged. Each of the drawing units Un draws a pattern for each local area divided in the Y direction of the substrate P supported by the outer peripheral surface (circumferential surface) of the rotating drum DR. Each drawing unit Un (U1 to U6) projects the light beam LBn from the light beam switching unit onto the substrate P (the illuminated surface of the substrate P), and condenses (converges) the light beam LBn on the substrate P. Thereby, the light beam LBn (LB1 to LB6) projected on the substrate P becomes the spot light SP. In addition, by the rotation of the polygon mirror PM of each drawing unit Un, the spot light SP of the light beam LBn (LB1 to LB6) projected on the substrate P is scanned in the main scanning direction (Y direction). By the scanning of the spot light SP, a linear drawing line (scanning line) SLn (n=1, 2, ..., 6) for drawing a pattern of one line is defined on the substrate P. The drawing line SLn is also the scanning track on the substrate P of the spot light SP of the light beam LBn.

The drawing unit U1 scans the spot light SP along the drawing line SL1. Similarly, the drawing units U2 to U6 scan the spot light SP along the drawing lines SL2 to SL6. As shown in Figure 1, the drawing lines SLn (SL1~SL6) of the plurality of drawing units Un (U1~U6) are separated by the center plane including the central axis AXo of the rotating drum DR and parallel to the YZ plane, and are located on the center plane of the rotating drum DR. It is arranged in a staggered arrangement in two rows in the circumferential direction. The odd-numbered drawing lines SL1, SL3, SL5 are located on the irradiated surface of the substrate P on the upstream side (-X direction side) of the conveying direction of the substrate P with respect to the center surface, and are arranged at a predetermined interval along the Y direction Into 1 row. The even-numbered drawing lines SL2, SL4, SL6 are located on the irradiated surface of the substrate P on the downstream side (+X direction side) in the conveying direction of the substrate P with respect to the center surface, and are arranged at predetermined intervals along the Y direction Into 1 row. Therefore, a plurality of drawing units Un (U1 to U6) are also arranged in a staggered arrangement in two rows in the conveying direction of the substrate P across the center plane. If viewed in the XZ plane, the odd-numbered drawing units U1, U3, U5 The even-numbered drawing units U2, U4, U6 are arranged symmetrically with respect to the center plane.

It is set so that the odd-numbered drawing lines SL1, SL3, SL5 and the even-numbered drawing lines SL2, SL4, SL6 are separated from each other in the X direction (the transport direction of the substrate P), but in the Y direction (the width direction of the substrate P, the main In the scanning direction), they are joined without being separated from each other. The drawing lines SL1 to SL6 are substantially parallel to the width direction of the substrate P, that is, the central axis AXo of the rotating drum DR. Furthermore, joining the drawing line SLn in the Y direction means that the ends of the drawing line SLn are adjacent to each other or partially overlapped in the Y direction. When the ends of the drawing lines SLn are overlapped with each other, for example, it is preferable to repeat the drawing start point or the drawing end point with respect to the length of each drawing line SLn by a few% or less in the Y direction.

In this way, the plurality of drawing units Un (U1 to U6) share the scanning area in the Y direction (division of the main scanning area) in a manner that all covers the size of the exposure area on the substrate P in the width direction. For example, if the main scanning range (length of the drawing line SLn) in the Y direction of one drawing unit Un is set to about 30-60 mm, a total of 6 drawing units U1 to U6 in the Y direction will be able to be drawn. The width of the exposure area in the Y direction is expanded to about 180~360mm. In addition, the length of each drawing line SLn (SL1 to SL6) (the length of the drawing range) is set to be the same in principle. That is, the scanning distance of the spot light SP of the light beam LBn scanned along each of the drawing lines SL1 to SL6 is set to be the same in principle.

In the case of this embodiment, when the light beam LB from the light source device LS is pulsed light with a light emission time of tens of picoseconds or less, the spot light SP projected on the drawing line SLn during the main scanning period depends on the oscillation frequency of the light beam LB Fa (for example, 400MHz) is discrete. Therefore, it is necessary to overlap the spot light SP projected by one pulse light of the light beam LB and the spot light SP projected by the next pulse light in the main scanning direction. The amount of overlap is set according to the size Φ of the spot light SP, the scanning speed of the spot light SP (the speed of the main scanning) Vs, and the oscillation frequency Fa of the light beam LB. When the intensity distribution of the spot light SP is approximated by a Gaussian distribution, the effective size (diameter) Φ of the spot light SP is determined by the width of the intensity that becomes ^{1/e 2 (or 1/2) of the peak intensity of the spot light SP} . In this embodiment, the scanning speed Vs (rotation speed of the polygon mirror PM) and the oscillation frequency Fa of the spot light SP are set such that the spot light SP overlaps Φ×1/2 with respect to the effective size (size) Φ. . Therefore, the projection interval of the pulse-shaped spot light SP along the main scanning direction becomes Φ/2. Therefore, it is preferable that in the sub-scanning direction (direction orthogonal to the drawing line SLn), the substrate P also moves the spot light SP between the first scan and the next scan of the spot light SP along the drawing line SLn The effective size Φ is approximately 1/2 of the distance. Furthermore, it is more desirable to also overlap Φ/2 when the drawing lines SLn adjacent in the Y direction are continuous in the main scanning direction. In this embodiment, the size (dimension) Φ of the spot light SP is set to approximately 3 to 4 μm.

Each drawing unit Un (U1~U6) is set in such a way that when viewed in the XZ plane, each light beam LBn travels toward the central axis AXo of the rotating drum DR. Thereby, the optical path of the light beam LBn (beam chief ray) traveling from each drawing unit Un (U1 to U6) toward the substrate P is parallel to the normal line of the illuminated surface of the substrate P on the XZ plane. In addition, the light beam LBn irradiated from each drawing unit Un (U1~U6) to the drawing line SLn (SL1~SL6) is always perpendicular to the cutting plane at the drawing line SLn of the surface of the substrate P curved in a cylindrical shape. Projected toward the substrate P. That is, in the main scanning direction of the spot light SP, the light beams LBn (LB1 to LB6) projected to the substrate P are scanned in a telecentric state.

The drawing unit (beam scanning device) Un shown in FIG. 1 has the same configuration, so only the drawing unit U1 will be briefly described. The detailed structure of the drawing unit U1 will be described below with reference to FIG. 2. The drawing unit U1 includes at least mirrors M20 to M24, a polygon mirror PM, and an fθ lens system (scanning lens for drawing) FT. Furthermore, in FIG. 1, although not shown, when viewed from the traveling direction of the light beam LB1, the first cylindrical lens CYa (refer to FIG. 2) is arranged in front of the polygon mirror PM, and the lens system (f-θ A second cylindrical lens CYb (refer to FIG. 2) is provided after the lens system) FT. The first cylindrical lens CYa and the second cylindrical lens CYb correct the positional change of the spot light SP (drawing line SL1) in the sub-scanning direction caused by the tilt error of each reflecting surface of the polygon mirror PM.

The light beam LB1 reflected by the incident mirror IM1 in the -Z direction is incident on the mirror M20 arranged in the drawing unit U1, and the light beam LB1 reflected by the mirror M20 travels in the -X direction and is incident on the mirror M21. The light beam LB1 reflected in the -Z direction by the mirror M21 enters the mirror M22, and the light beam LB1 reflected in the mirror M22 travels in the +X direction and enters the mirror M23. The reflecting mirror M23 reflects the incident light beam LB1 in a way that the reflecting surface RP of the polygon mirror PM is bent in a plane parallel to the XY plane.

The polygon mirror PM reflects the incident light beam LB1 toward the fθ lens system FT toward the +X direction side. The polygon mirror PM scans the spot light SP of the light beam LB1 on the illuminated surface of the substrate P, and deflects (reflects) the incident light beam LB1 one-dimensionally in a plane parallel to the XY plane. Specifically, the polygon mirror (rotating polygon mirror, movable deflection member) PM has a rotation axis AXp extending in the Z-axis direction, and a plurality of reflection surfaces RP formed around the rotation axis AXp (in this embodiment, the reflection The number Np of the surface RP is set to 8) a rotating polygon mirror. By rotating the polygon mirror PM in a predetermined rotation direction with the rotation axis AXp as the center, the reflection angle of the pulse-shaped light beam LB1 irradiated on the reflection surface can be continuously changed. Thereby, the light beam LB1 can be deflected by one reflecting surface RP, and the spot light SP of the light beam LB1 irradiated on the illuminated surface of the substrate P can be scanned along the main scanning direction (the width direction of the substrate P, the Y direction) . Therefore, in one revolution of the polygon mirror PM, the number of drawing lines SL1 scanned by the spot light SP on the illuminated surface of the substrate P is the same as the number of the reflecting surface RP at the maximum 8.

The fθ lens system (scanning system lens, scanning optical system) FT is a scanning lens of the telecentric system that projects the light beam LB1 reflected by the polygon mirror PM to the mirror M24. The light beam LB1 that has passed through the fθ lens system FT passes through the mirror M24 to become a spot light SP and is projected onto the substrate P. At this time, the mirror M24 reflects the light beam LB1 toward the substrate P in a manner that the light beam LB1 travels toward the central axis AXo of the rotating drum DR in the XZ plane. The incident angle θ of the light beam LB1 toward the fθ lens system FT changes according to the rotation angle (θ/2) of the polygon mirror PM. The fθ lens system FT transmits the mirror M24 to project the light beam LB1 to the image height position on the illuminated surface of the substrate P proportional to the incident angle θ. If the focal distance of the fθ lens system FT is set to fo and the image height position is set to yo, the fθ lens system FT is designed to satisfy the relationship of yo=fo×θ (distortion aberration). Therefore, the light beam LB1 can be scanned accurately and uniformly in the Y direction by the fθ lens system FT. Furthermore, the surface (parallel to the XY plane) to which the light beam LB1 incident to the fθ lens system FT is one-dimensionally deflected by the polygon mirror PM becomes a surface including the optical axis AXf of the fθ lens system FT.

Next, the optical configuration of the drawing unit Un (U1 to U6) will be described with reference to FIG. 2. As shown in FIG. 2, in the drawing unit Un, a mirror M20, a mirror M20a, and a polarization beam splitter BS1 are provided along the traveling direction of the light beam LBn from the incident position of the light beam LBn to the illuminated surface (substrate P). The reflecting mirror M21, the reflecting mirror M22, the first cylindrical lens CYa, the reflecting mirror M23, the polygon mirror PM, the fθ lens system FT, the reflecting mirror M24, and the second cylindrical lens CYb. Furthermore, in the drawing unit Un, in order to detect the drawing start timing of the drawing unit Un (scanning start timing of the spot light SP), an origin detection sensor for detecting the angular position of each reflecting surface of the polygon mirror PM is provided The beam transmitting system 60a and the beam receiving system 60b of the detector (origin detector). In addition, a photodetector DTc is provided in the drawing unit Un. The photodetector DTc is used to detect the irradiated surface (or rotating cylinder The surface of the DR) the reflected light of the reflected light beam LBn.

The light beam LBn incident on the drawing unit Un travels in the -Z direction along the optical axis AX1 parallel to the Z axis, and is incident on the mirror M20 inclined by 45° with respect to the XY plane. The light beam LBn reflected by the mirror M20 travels toward the mirror M20a away from the mirror M20 in the -X direction and travels in the -X direction. The mirror M20a is arranged at an angle of 45° with respect to the YZ plane, and reflects the incident light beam LBn toward the polarization beam splitter BS1 in the -Y direction. The polarization separation surface of the polarization beam splitter BS1 is arranged at an incline of 45° with respect to the YZ plane, and reflects the P-polarized light beam and transmits the linearly polarized light (S-polarized light) beam that is polarized in the direction orthogonal to the P polarization. If the light beam LBn incident on the drawing unit Un is a P-polarized light beam, the polarization beam splitter BS1 reflects the light beam LBn from the mirror M20a in the -X direction and guides it to the mirror M21 side. The mirror M21 is arranged at an angle of 45° with respect to the XY plane, and reflects the incident light beam LBn in the -Z direction toward the mirror M22 that is away from the mirror M21 in the -Z direction. The light beam LBn reflected by the mirror M21 is incident on the mirror M22. The mirror M22 is arranged at an angle of 45° with respect to the XY plane, and the incident light beam LBn is directed toward the mirror M23 and reflected in the +X direction. The light beam LBn reflected by the mirror M22 passes through the λ/4 wave plate and the cylindrical lens CYa (not shown), and is incident on the mirror M23. The mirror M23 reflects the incident light beam LBn toward the polygon mirror PM.

The polygon mirror PM reflects the incident light beam LBn toward the fθ lens system FT having an optical axis AXf parallel to the X axis toward the +X direction side. The polygon mirror PM scans the spot light SP of the light beam LBn on the illuminated surface of the substrate P, and deflects (reflects) the incident light beam LBn one-dimensionally in a plane parallel to the XY plane. The polygon mirror PM has a plurality of reflecting surfaces (each side of the regular octagon in this embodiment) formed around the rotation axis AXp extending in the Z-axis direction, and is formed by the rotation motor RM coaxial with the rotation axis AXp Spin. The rotation motor RM is rotated at a fixed rotation speed (for example, about 30,000 to 40,000 rpm) by a drawing control device not shown. As explained above, the effective length (for example, 50mm) of the drawing lines SLn (SL1~SL6) is set to a length below the maximum scanning length (for example, 52mm) that can be scanned by the polygon mirror PM. In the initial setting (design), the center point of the drawing line SLn (the point through which the optical axis AXf of the fθ lens system FT passes) is set at the center of the maximum scanning length.

The cylindrical lens CYa converges the incident light beam LBn on the reflecting surface of the polygon mirror PM in the sub-scanning direction (Z direction) orthogonal to the main scanning direction (rotation direction) of the polygon mirror PM. That is, the cylindrical lens CYa converges the light beam LBn on the reflecting surface of the polygon mirror PM into a slit shape (oblong shape) extending in a direction parallel to the XY plane. With the cylindrical lens CYa whose generatrix is parallel to the Y direction and the cylindrical lens CYb described below, even when the reflecting surface of the polygon mirror PM is tilted from the state parallel to the Z axis, the substrate P can be prevented from being irradiated The irradiation position of the light beam LBn (drawing line SLn) on the irradiation surface is shifted in the sub-scanning direction.

字狀彎曲之光路彎折，且朝-Z方向行進並投射至基板P。一面使6個描繪單元U1~U6之各者將光束LB1~LB6之各點光SP於主掃描方向(Y方向)上一維地進行掃描，一面將基板P於長條方向上進行搬送，藉此，利用點光SP將基板P之被照射面相對地進行二維掃描，於基板P上使利用描繪線SL1~SL6之各者所描繪之圖案以於Y方向上接合之狀態曝光。 The incident angle θ of the light beam LBn toward the fθ lens system FT (the angle relative to the optical axis AXf) changes according to the rotation angle (θ/2) of the polygon mirror PM. When the incident angle θ of the light beam LBn toward the fθ lens system FT is 0 degrees, the light beam LBn incident on the fθ lens system FT travels along the optical axis AXf. The light beam LBn from the fθ lens system FT is reflected by the mirror M24 in the -Z direction, passes through the cylindrical lens CYb, and is projected toward the substrate P. With the fθ lens system FT and the cylindrical lens CYb whose bus bar is parallel to the Y direction, the light beam LBn projected to the substrate P converges on the illuminated surface of the substrate P into a tiny spot light with a diameter of about several μm (for example, 2~3 μm) SP. As described above, when viewed in the XZ plane, the light beam LBn incident on the drawing unit Un follows from the mirror M20 to the substrate P.

The curved light path in the shape of a letter bends, travels in the -Z direction and is projected onto the substrate P. While allowing each of the six drawing units U1 to U6 to scan each spot light SP of the beams LB1 to LB6 one-dimensionally in the main scanning direction (Y direction), while conveying the substrate P in the longitudinal direction, Here, the illuminated surface of the substrate P is relatively scanned two-dimensionally by the spot light SP, and the pattern drawn by each of the drawing lines SL1 to SL6 is exposed on the substrate P in a state of being joined in the Y direction.

As an example, the effective scanning length LT of the drawing line SLn (SL1~SL6) is set to 50mm, the effective diameter Φ of the spot light SP is set to 4μm, and the oscillation frequency Fa of the pulse emission of the light beam LB from the light source device LS is set to For 400MHz, when the spot light SP is pulsed along the drawing line SLn (main scanning direction) in a manner that overlaps 1/2 of the diameter Φ each time, the pulse light emission of the spot light SP is separated from the substrate P in the main scanning direction The upper part becomes 2 μm, and this interval corresponds to the period Tf (=1/Fa) of the oscillation frequency Fa, that is, 2.5 nS (1/400 MHz). In this case, the pixel size Pxy specified on the drawing data is set to a 4 μm square on the substrate P, and one pixel is exposed with 2 pulses of the spot light SP in each of the main scanning direction and the sub scanning direction. Therefore, the scanning speed Vsp in the main scanning direction of the spot light SP and the oscillation frequency Fa are set to a relationship of Vsp=(Φ/2)/Tf. On the other hand, the scanning speed Vsp is based on the rotation speed VR (rpm) of the polygon mirror PM, the effective scanning length LT, the number of reflection surfaces of the polygon mirror PM Np (=8), and one reflection surface RP of the polygon mirror PM. The scanning efficiency 1/α is determined as follows.

Vsp=(8．α．VR．LT)/60[mm/sec]

Therefore, the oscillation frequency Fa and the rotation speed VR (rpm) are set in the following relationship.

(Φ/2)/Tf=(8．α．VR．LT)/60...Equation (1)

When the oscillation frequency Fa is set to 400 MHz (Tf=2.5nS) and the diameter Φ of the spot light SP is set to 4 μm, the scanning speed Vsp prescribed by the oscillation frequency Fa becomes 0.8 μm/nS (=2 μm/2.5nS). In order to cope with the scanning speed Vsp, when the scanning efficiency 1/α is set to 0.3 (α≒3.33) and the scanning length LT is set to 50mm, according to the relationship of formula (1), only the 8-sided polygon mirror PM The rotation speed VR can be set to 36000rpm. Furthermore, the scanning speed Vsp=0.8μm/nS in this case is 2880Km/h if converted to a speed per hour. In this way, if the scanning speed Vsp becomes high, it is necessary to improve the reproducibility of the origin signal generation timing from the origin sensors (beam light transmitting system 60a and light beam receiving system 60b) that determine the starting timing of pattern drawing. For example, when the size of 1 pixel is set to 4μm, and the minimum size (minimum line width) of the pattern to be drawn is set to 8μm (equivalent to the amount of 2 pixels), the pattern that has been formed on the substrate P is superimposed and exposed to a new The overlap accuracy (the allowable position error range) of the pattern during the second exposure must be set to about 1/4~1/5 of the minimum line width. That is, when the minimum line width is 8μm, the allowable range of position error becomes 2μm~1.6μm. This value is equal to or less than the interval of 2 pulses of the spot light SP corresponding to the oscillation period Tf (2.5 nS) of the light beam LB from the light source device LS, and means that the error of 1 pulse of the spot light SP is not allowed. Therefore, the reproducibility of the origin signal generation timing that determines the drawing start timing (start position) of the pattern must be set to the period Tf (2.5nS) or less.

The light beam receiving system 60b that constitutes the origin detection sensor (hereinafter also referred to as the origin sensor) shown in FIG. The origin signal SZn is generated at a predetermined position before the scanning of the spot light SP of the light beam LBn for drawing. Since the polygon mirror PM has 8 reflecting surfaces RP, the light beam receiving system 60b outputs the origin signal SZn 8 times during one revolution of the polygon mirror PM. The origin signal SZn is sent to a drawing control device not shown. After a predetermined delay time Tdn has elapsed after the origin signal SZn is generated, the scanning of the spot light SP along the drawing line SLn is started.

FIG. 3 is a diagram obtained by observing the configuration of the polygon mirror PM, the fθ lens system FT, and the light beam receiving system 60b constituting the origin sensor (origin detector in a broad sense) in the drawing unit Un in the XY plane. 3 shows that one of the reflective surfaces RP of the polygon mirror PM projects the laser beam Bga from the beam delivery system 60a toward one of the reflective surfaces RP of the polygon mirror PM, and the point light SP of the drawing beam LBn scanned within the angular range θf is located The angular state of the reflective surface RPa at the moment when the drawing start point of the drawing line SLn is drawn. Here, the reflecting surface RP (RPa) of the polygon mirror PM is arranged so as to be located on the entrance pupil surface orthogonal to the optical axis AXf of the fθ lens system FT. Strictly speaking, the principal ray of the light beam LBn incident on the fθ lens system FT becomes the angular position of the reflective surface RP (RPa) at the moment when it is coaxial with the optical axis AXf, and the principal ray of the light beam LBn from the mirror M23 toward the polygon mirror PM The position where the light crosses the optical axis AXf sets the reflecting surface RP (RPa). In addition, the distance from the principal surface of the fθ lens system FT to the surface of the substrate P (the condensing point of the spot light SP) is the focal distance fo.

The laser beam Bga is projected to the reflective surface RPa as a parallel beam of a wavelength region in which the photosensitive functional layer of the substrate P is non-photosensitive. The reflected beam Bgb of the laser beam Bga reflected on the reflecting surface RPa faces the direction of the fθ lens system FT in the state of FIG. 3, but relative to the position of FIG. 3 before a fixed time, the reflecting surface RPa becomes the angle of the reflecting surface RPa' At the position, the reflected light beam Bgb enters the lens system (optical element) GLb constituting the light beam receiving system 60b, is reflected by the mirror Mb, and reaches the photoelectric conversion element (photodetector) DTo. The reflected light beam Bgb (parallel light beam) is condensed by the lens system GLb on the light-receiving surface of the photoelectric conversion element DTo into a point light SPr. During the period when the reflected light beam Bgb enters the lens system GLb, the point light SPr is accompanied by the polygon mirror PM It rotates and scans across the light-receiving surface of the photoelectric conversion element DTo, and the photoelectric conversion element (origin detector in a narrow sense) DTo generates an origin signal SZn. In this embodiment, in order to improve the reproducibility of the generation timing of the origin signal SZn, the point of the origin detection reflected light beam Bgb is compared with the scanning speed Vsp of the point light SP of the drawing light beam LBn on the substrate P The scanning speed of the light SPr on the photoelectric conversion element DTo is increased so that the focal distance of the lens system GLb is greater than the focal distance fo of the fθ lens system FT.

Fig. 4 is a simplified diagram showing the configuration of the beam delivery system 60a and the beam receiving system 60b shown in Figs. (Hereinafter also referred to as light beam Bga for short); and a collimating lens (lens system) GLa, which turns the light beam Bga from the light source into a parallel light beam. In order to detect the angle change of the reflecting surface RP (RPa) of the polygon mirror PM with high accuracy and stably, the beam Bga projected on the reflecting surface RP (RPa) is set in the rotation direction of the reflecting surface RP (RPa) (parallel to the XY plane) A parallel beam with a certain width in the main scanning direction). On the other hand, as for the light beam receiving system 60b, it is preferable that the reflected light beam Bgb be condensed on the photoelectric conversion element DTo into a spot light SPr that shrinks smaller in the main scanning direction. For this purpose, a lens system GLb with a focal distance Fgs is provided. Since the reflected light beam Bgb becomes a parallel light beam, the distance from the reflecting surface RP (RPa) of the polygon mirror PM to the lens system GLb can be set relatively freely. The light-receiving surface of the photoelectric conversion element DTo is arranged at the position of the focal distance Fgs on the rear side of the lens system GLb. When the reflected light beam Bgb reflected on the reflective surface RP (RPa) is incident coaxially with the optical axis of the lens system GLb, the spot light SPr of the reflected light beam Bgb is set to be located approximately in the center of the light-receiving surface of the photoelectric conversion element DTo.

Even when the reflected light beam Bgb' which is slightly inclined toward the main scanning direction with respect to the optical axis of the lens system GLb is incident, the reflected light beam Bgb' becomes a point light SPr and is focused on the light receiving surface of the photoelectric conversion element DTo. In-plane. The reflected light beam Bgb′ from the lens system GLb toward the photoelectric conversion element DTo does not need to be telecentric. In order to further increase the speed of the spot light SPr that crosses the light receiving surface of the photoelectric conversion element DTo, it is better not to be telecentric. As described above, by setting the focal distance Fgs of the lens system GLb and the focal distance fo of the fθ lens system FT to Fgs>fo, the reproducibility of the generation timing of the origin signal SZn output from the photoelectric conversion element DTo can be improved (correct sex). The method for seeking the reproducibility of the origin signal SZn or the degree of improvement of the reproducibility will be described below.

FIG. 5 shows the detailed structure of the photoelectric conversion element DTo. In this embodiment, for example, the S9684 series manufactured by Hamamatsu Photonics Co., Ltd. and sold as a photoelectric IC for laser beam synchronization detection is used. This photo-IC is the light-receiving surface PD1, PD2, and current amplifying parts IC1, IC2 of two PIN photodiodes arranged in the scanning direction of the spot light SPr with a narrow gap (non-sensitive band) as shown in Figure 5. And the comparator IC3 is packaged as a whole. If the spot light SPr traverses the light receiving surfaces PD1 and PD2 in the order, each of the current amplifying parts IC1 and IC2 generates output signals STa and STb as shown in FIG. 5(A). A fixed offset voltage (reference voltage) Vref is applied to the current amplifying part IC1 that amplifies the photocurrent from the light-receiving surface PD1 that first receives the spot light SPr, so that the output signal STa of the current amplifying part IC1 is the light generated on the light-receiving surface PD1 When the current is zero, the bias voltage becomes the reference voltage Vref. As shown in Figure 5(B), the comparator IC3 compares the levels of the output signals STa and STb, and outputs the logic signal that becomes the H level when STa>STb and becomes L when STa<STb is the origin. Signal SZn. In this embodiment, the time point when the origin signal SZn changes from the H level to the L level is set as the origin time (origin position) Tog. The so-called origin signal SZn generation timing refers to the origin time Tog . In addition, the origin position (origin time Tog) here does not mean, for example, when the point on the substrate P through which the optical axis AXf of the fθ lens system FT passes is set as the reference point, the reference point is The main scanning direction of the spot light SP is always separated by a fixed distance from the origin of the absolute position, but it is relative to the predetermined distance (or before the predetermined time) relative to the start sequence of the pattern drawing along the drawing line SLn. By.

The origin time Tog becomes the moment when the levels of the output signals STa and STb coincide in the middle of the decrease of the level of the output signal STa and the increase of the level of the output signal STb. The level change of the output signal STa, STb (rising or falling waveform) can be based on the relationship between the width of the light receiving surface PD1, PD2 and the size of the spot light SPr, the scanning speed Vh of the spot light SPr and the response of the light receiving surface PD1, PD2 However, as long as the diameter of the spot light SPr is larger than the width of the non-sensitive zone and smaller than the width of the light-receiving surface PD1, each of the output signals STa and STb becomes the result of using level changes as shown in Figure 5(A) The waveform can obtain a stable origin signal SZn.

Fig. 6 shows a schematic configuration of a light beam switching unit including a selection optical element OSn ( OS1~OS6). Although the symbols of the components in FIG. 6 are the same as the components shown in FIG. 1, the mirrors M1 to M12 shown in FIG. 1 are appropriately omitted. The light source device LS composed of a fiber-amplified laser light source is connected to the drawing control device 200, and various control information SJ is exchanged. The light source device LS is equipped with a clock circuit that generates a clock signal CLK of the oscillation frequency Fa (for example, 400MHz) when the light beam LB is pulsed, based on the drawing data SDn( Set 1 pixel as 1-bit bitmap data), make the light beam LBn respond to the clock signal CLK to emit light in burst mode (corresponding to the predetermined number of clock pulses and corresponding to the predetermined number of clock pulses Repetition of stop of light emission) pulse light emission.

The drawing control device 200 is equipped with a polygon mirror rotation control unit, which inputs the origin signal SZn (SZ1~SZ6) output from the origin sensor (photoelectric conversion element DTo) of each of the drawing units U1 to U6, and is used as the drawing unit The rotation speed and the rotation angle phase of the polygon mirror PM of each of U1~U6 are in the specified state, and the rotation motor RM of the polygon mirror PM is controlled; and the beam switching control unit, which is based on the origin signal SZn (SZ1~SZ6) And it controls the on/off (applied/non-applied) of driving signals DF1~DF6 as the ultrasonic signals supplied to each of the optical elements OSn (OS1~OS6) for selection. Furthermore, in FIG. 6, it is shown that the selection optical element OS4 among the six selection optical elements OS1 to OS6 is selected, and the light beam LB from the light source device LS (in accordance with the drawing data of the pattern drawn by the drawing unit U4 is intensified) Modulation) A state where it is deflected toward the entrance mirror IM4 and is supplied to the drawing unit U4 as a light beam LB4. In this way, if the optical elements for selection OS1 to OS6 are arranged in series in the optical path of the light beam LB, according to the transmittance or diffraction efficiency of each of the optical elements for selection OSn, the optical elements for selection corresponding to the light source device LS The order of the element OSn differs in the intensity of the selected light beams LB1~LB6 (the peak intensity of the pulsed light). Therefore, the drawing control device 200 adjusts the driving signals DF1 to DF6 in such a way that the relative intensity difference of the light beams LB1 to LB6 incident on each of the drawing units U1 to U6 is within a predetermined allowable range (for example, within ±5%) The level of each of them (the amplitude or power of the high-frequency signal).

Fig. 7 is a diagram showing the specific configuration around the selection optical element OSn (OS1~OS6) and the incident mirror IMn (IM1~IM6). The light beam LB emitted from the light source device LS is incident on the selection optical element OSn as, for example, a parallel light beam with a small diameter (first diameter) of 1 mm or less in diameter. During the period when the driving signal DFn as a high-frequency signal (ultrasonic signal) is not input (the driving signal DFn is off), the incident light beam LB is directly transmitted without being diffracted by the selective optical element OSn. The transmitted light beam LB passes through the condenser lens Ga and the collimator lens Gb arranged on the optical path along the optical axis AXb, and enters the optical element OSn for selection in the subsequent stage. At this time, the light beam LB system passing through the condenser lens Ga and the collimating lens Gb after passing through the optical element OSn for selection is set to be coaxial with the optical axis AXb. The condensing lens Ga condenses the light beam LB (parallel beam) passing through the optical element OSn for selection so that the position of the surface Ps between the condensing lens Ga and the collimating lens Gb becomes the beam waist. The collimator lens Gb forms the light beam LB diverging from the position of the plane Ps into a parallel light beam. The diameter of the beam LB formed into a parallel beam by the collimator lens Gb becomes the first diameter. The focal position behind the condenser lens Ga and the front focal position of the collimator lens Gb are consistent with the plane Ps within a predetermined allowable range, and the front focal position of the condenser lens Ga is aligned with the diffraction point in the selection optical element OSn Configure in a consistent manner within the established allowable range.

On the other hand, during the period when the drive signal DFn, which is a high-frequency signal, is applied to the selection optical element OSn, the incident light beam LB is generated after being diffracted by the selection optical element OSn (primary diffracted light), And the undiffracted 0-order beam LBnz. When the intensity of the incident light beam LB is set to 100%, and the decrease caused by the transmittance of the optical element OSn for selection is ignored, the intensity of the diffracted light beam LBn is about 80% at the maximum, and the remaining 20% becomes 0. The intensity of the secondary beam LBnz. The 0-order light beam LBnz passes through the condenser lens Ga and the collimator lens Gb, and then passes through the optical element OSn for selection in the latter stage, and is absorbed by the absorber TR. The beam LBn (parallel beam) deflected in the -Z direction at the diffraction angle corresponding to the high frequency frequency of the driving signal DFn passes through the condenser lens Ga and faces the incident mirror IMn provided on the surface Ps. The focal position on the front side of the condenser lens Ga and the diffraction point in the selection optical element OSn are optically conjugated. Therefore, the light beam LBn from the condenser lens Ga toward the incident mirror IMn is decentered from the optical axis AXb. The axis AXb travels in parallel, and the light is condensed (converged) in such a way that the position of the surface Ps becomes the beam waist. The position of the beam waist is set so as to be optically conjugate with the spot light SP projected on the substrate P through the drawing unit Un.

By arranging the reflecting surface of the incident mirror IMn or its vicinity at the position of the plane Ps, the light beam LBn diffracted by the selective optical element OSn is reflected by the incident mirror IMn in the -Z direction, and passes through the collimating lens Gc along The optical axis AX1 (refer to FIG. 2) is incident on the drawing unit Un. The collimator lens Gc forms the light beam LBn converged/diverged by the condenser lens Ga into a parallel light beam coaxial with the optical axis (AX1) of the collimator lens Gc. The diameter of the beam LBn formed as a parallel beam by the collimator lens Gc is substantially the same as the first diameter. The back focus of the condenser lens Ga and the front focus of the collimator lens Gc are arranged on or near the reflecting surface of the incident mirror IMn within a predetermined allowable range.

As described above, when the focal position on the front side of the condenser lens Ga is optically conjugated with the diffraction point in the selection optical element OSn, and the incident mirror IMn is arranged at the focal position on the rear side of the condenser lens Ga, that is, the plane Ps, The frequency of the driving signal DFn of the optical element OSn for selection is changed from the predetermined frequency by ±ΔFs, whereby the eccentric amount (shift amount) of the condensing point on the plane Ps of the light beam LBn with respect to the optical axis AXb can be changed. As a result, the spot light SP of the light beam LBn projected from the drawing unit Un onto the substrate P can be shifted by ±ΔSFp in the sub-scanning direction. This shift amount (｜△SFp｜) is subject to the maximum range of the deflection angle of the selection optical element OSn itself, the size of the reflecting surface of the incident mirror IMn, and the optical system (relay) up to the polygon mirror PM in the drawing unit Un System), the width of the reflective surface RP of the polygon mirror PM in the Z direction, the magnification from the polygon mirror PM to the substrate P (the magnification of the fθ lens system FT), etc., but it can be placed on the substrate P of the spot light SP The effective size (diameter) or the pixel size (Pxy) defined on the drawing data can be adjusted. Thereby, it is possible to correct the overlap error between the new pattern drawn on the substrate P by each of the drawing units Un and the pattern already formed on the substrate P with high accuracy and high speed, or drawing on the substrate P by each of the drawing units Un The joint error between the new patterns on the above.

Next, referring to Figures 8 and 9, the reproducibility of the origin signal SZn generation timing from the origin sensor (beam transmitting system 60a and beam receiving system 60b) constructed in the manner shown in Figures 3 and 4 will be described. (Deviation error) The method of measurement and calculation. The measurement or calculation can be implemented by the processor (CPU (Central Processing Unit, Central Processing Unit)) in the drawing control device 200 shown in FIG. 6, or the origin signal SZn can be sent to an external waveform measurement device, etc. Implement. Fig. 8 is a plan view of the 8-sided polygon mirror PM shown in Fig. 3 or Fig. 4. Here, the reproducibility of the origin signal SZn generated as shown in Fig. 5(B) is obtained for each of the 8 reflecting surfaces RP Therefore, the rotation direction (clockwise) of the eight reflecting surfaces RP and the polygon mirror PM can be reversed to RPa, RPb, RPc, RPd, RPe, RPf, RPg, RPh. In addition, on the upper surface (or lower surface) of the polygon mirror PM, a rotation reference mark Mcc useful for detecting the origin of the rotation of the polygon mirror PM is formed. The rotation reference mark Mcc is detected by a reflection type photoelectric sensor (also called a rotation detection sensor) that outputs a pulse-shaped detection signal every time the polygon mirror PM rotates one turn. When measuring the reproducibility of the origin signal SZn, the reflecting surface of the polygon mirror PM detected by the origin sensor must be specified. Therefore, the detection signal from the rotation detection sensor (rotation reference mark Mcc) is used as the reference to specify Each reflecting surface RPa~RPh of the polygon mirror PM is shown.

Furthermore, when measuring the reproducibility of the generation timing of the origin signal SZn, the influence caused by the speed variation (speed unevenness) of the polygon mirror PM must be considered. The speed variation of the polygon mirror PM can also be measured by the above-mentioned rotation detection sensor, but in this embodiment, the speed variation of the polygon mirror PM is measured based on the origin signal SZn. As exemplified above, if the polygon mirror PM is set to rotate at 36000 rpm and the polygon mirror rotation control part in the drawing control device 200 is used for servo control, the polygon mirror PM will rotate 600 times in 1 second. The rotation time TD for one revolution of the upper is 1/600 second (≒1666.667μS). Therefore, a clock pulse with a higher frequency (for example, 2 times or more) than the oscillation frequency Fa of the light source device LS for pulsed light emission is used to repeatedly measure the origin time Tog of any pulse from the origin signal SZn and count to the first The actual rotation time TD until the origin time Tog of 9 pulses. The polygon mirror PM rotates at a high speed with inertia, so the possibility of uneven speed during one rotation is low. According to the characteristics of the servo control, there is a design rotation time within a period of several mS to tens of mS. TD changes slightly.

FIG. 9 is a diagram illustrating a method of measuring the reproducibility (deviation) of the generation timing of the origin signal SZn. Here, in order to simplify the description, an example of the method of seeking the reproducibility of the origin time Tog2 of the origin signal SZn generated corresponding to the reflecting surface RPa of the polygon mirror PM shown in FIG. 8 is shown for each of the other reflecting surfaces RPb~RPh The same can also be done for measurement. In the case of FIG. 8, the origin time Tog1 generated one time sequence before the origin time Tog2 can be obtained as the origin signal SZn generated corresponding to the reflecting surface RPh of the polygon mirror PM. Therefore, in the state that the polygon mirror PM is rotated at a predetermined speed, the polygon mirror PM repeats the measurement multiple times (for example, more than 10 times) every time the polygon mirror PM rotates one turn. The origin interval time △Tmn (the number of rotations of n=1, 2, 3...) to the origin time Tog2 of the next reflecting surface RPa. In FIG. 9, in order to simplify the description, the origin time Tog1 obtained corresponding to the reflecting surface RPh is aligned on the time axis to represent the origin signal SZn( a) The waveform of each of 1~SZn(a)7.

Here, if it is assumed that the variation of the rotation speed of the polygon mirror PM is zero, the measured value of each of the original interval time ΔTmn, which should have been fixed, will deviate. This deviation becomes the deviation amount △Te of the generation sequence of the origin time Tog2 corresponding to the reflecting surface RPa, and the reproducibility of the origin signal SZn is set as the standard deviation value of the plural origin time Tog2 distributed within the deviation amount △Te σ, or a 3σ value that is three times the standard deviation value σ. As explained above, when the light source device LS pulses the light beam LB with the period Tf, the 3σ value as the reproducibility is preferably smaller than the period Tf. In the above description, although the rotation speed variation (speed unevenness) of the polygon mirror PM is assumed to be zero, if a waveform tester that samples the signal waveform with a resolution of less than nanoseconds is used to analyze the origin signal SZn waveform, and try to measure the rotation time of the polygon mirror PM (the time of one rotation), and it is judged that the rotation time changes due to the rotation by ± a few nS. Therefore, the origin interval time ΔTmn (the number of rotations for n=1, 2, 3...) measured in the manner shown in Fig. 9 must correspond to the polygon mirror PM during the measurement period due to the origin interval time ΔTmn The amount of error caused by the speed change is corrected.

FIG. 10 is a diagram schematically showing a method of predicting the amount of time error caused by the speed variation of the polygon mirror PM. In this embodiment, for each of the multiple rotations of the polygon mirror PM, the origin interval time ΔTmn corresponding to each of the eight reflecting surfaces RPa~RPh is measured. In Fig. 10, it is schematically shown that the initial position (initial origin time Tog) of the polygon mirror PM in one revolution is set as the reflective surface RPa, and it is generated during the period of 2 revolutions of the polygon mirror PM from the reflective surface RPa. The waveform of the origin signal SZn. Here, the origin time interval from the origin time Tog generated by the reflection surface RPa corresponding to the origin signal SZn to the origin time Tog generated corresponding to the adjacent reflection surface RPb is set as △Tma, the following Similarly, let the origin interval time from the adjacent reflecting surface RPb to the reflecting surface RPc be ΔTmb, and let the origin interval time from the adjacent reflecting surface RPh to the reflecting surface RPa be ΔTmh. In the first week of the polygon mirror PM, set each origin time Tog corresponding to each of the 8 reflecting surfaces RPa~RPh as the starting point, and measure each of the reflecting surfaces RPa~RPh of the polygon mirror PM The rotation time TDa, TDb,...TDh. Each of the rotation time TDa~TDh can also be obtained by the total value of the 8 origin interval time △Tma~△Tmh corresponding to each of the 8 reflecting surfaces RPa~RPh. Each of the rotation time TDa ~ TDh (or the origin interval time △Tma ~ △Tmh) is repeatedly measured during the period when the polygon mirror PM rotates, for example, N revolutions. Thereby, the data of each of the rotation time TDa~TDh counted from the origin time Tog corresponding to each of the 8 reflecting surfaces RPa~RPh can be obtained continuously for N revolutions.

Secondly, calculate the average rotation time ave(TDa)~ave(TDh) of each of the rotation times TDa~TDh obtained for N cycles. For example, the rotation time TDa corresponds to the number of rotations N (N=1, 2, 3...) and is memorized as TDa(1), TDa(2), TDa(3),...TDa(N), so the average rotation time ave (TDa) can be calculated using [TDa(1)+TDa(2)+TDa(3)+,...+TDa(N)]/N.

Secondly, suppose that each of the origin interval time △Tma~△Tmh measured after the second circle shown in Fig. 10 includes the error caused by the influence of the speed change of the previous polygon mirror PM. For example, regarding the first The measured interval time between the origins △Tma after 2 laps, the prediction is only based on the ratio of the measured rotation time TDa and the average rotation time ave(TDa) in the previous rotation, and the predicted interval time △Tma of the initial interval time △Tma is calculated. Tma'. At this time, find the average interval time ave (ΔTma) of the N-1 origin interval time ΔTma measured in each rotation after the second turn. Then, the ratio of the average rotation time ave (TDa) to the measured rotation time TDa is multiplied by the average interval time ave (ΔTma) to calculate the predicted interval time ΔTma' after the amount of speed variation is corrected. By this, the difference between the measured origin interval time ΔTma and the predicted interval time ΔTma' is set to correspond to the more accurate deviation (σ value) of the origin time Tog generated by the reflecting surface RPa. . The deviation amount of the origin time Tog of the origin signal SZn corresponding to each of the other reflecting surfaces RPb~RPh is also calculated by the same calculation. In this way, only by repeating the generation interval of the origin time Tog of the actual measured origin signal SZn during the multiple rotations of the polygon mirror PM, that is, the origin interval time △Tma~△Tmh, the use of the polygon mirror PM can be obtained. Accurate reproducibility (3σ value, etc.) of the error reduction caused by the speed change.

[Measured example]

As an example, the focal distance Fgs of the lens system GLb in the beam receiving system 60b of the origin sensor is set to be the same as the focal distance fo (for example, 100mm) of the fθ lens system FT, and the photoelectric conversion element DTo is arranged in the lens system The focal point of GLb is at the position of Fgs, and the polygon mirror PM is rotated at about 38000 rpm, and the origin signal SZn (origin point time After the reproducibility of Tog2), the result shown in Figure 11 can be obtained. In Figure 11, the horizontal axis represents the positions between the measured reflecting surfaces (RPa→RPb, RPb→RPc,...RPh→RPa), and the vertical axis represents the distance between the reflecting surfaces after the correction calculation for the change in the rotation speed Interval time △Tma~△Tmh(μS). In this embodiment, the interval time △Tma~△Tmh uses a digital waveform memory device with a sampling frequency of 2.5GHz (0.4nS) to memorize the waveform data of the origin signal SZn generated continuously during 10 revolutions of the polygon mirror PM , And analyze and measure the waveform data.

As shown in Figure 11, the interval time △Tma~△Tmh after the change of the rotation speed is corrected has a deviation between 197.380μS~197.355μS. When the polygon mirror PM rotates precisely at a rotation speed of 38000 rpm, the calculated interval time △Tma~△Tmh is 197.368μS. The deviation of this interval time △Tma~△Tmh, for example, is due to the fact that each of the 8 vertex angles formed by the adjacent reflective surfaces of the polygonal mirror PM's reflective surfaces RPa~RPh does not accurately become 135 degrees, or self The distance from the rotation axis AXp to each of the reflecting surfaces RPa~RPh does not accurately become a shape error in processing such as a fixation. In addition, the deviation of the interval time △Tma~△Tmh will also be generated according to the degree of the eccentricity error of the polygon mirror PM with respect to the rotation axis AXp. In Fig. 11, the 3σ value calculated based on the distribution of the deviation of each of the interval time △Tma~△Tmh becomes 2.3nS~5.9nS. This value means that when the pulse oscillation frequency of the light beam LB from the light source device LS is set to 400 MHz (period: 2.5 nS), an error of approximately 3 pulses or more occurs with respect to the scanning position of the spot light. As exemplified above, when the diameter Φ of the spot light SP is set to 4 μm, the size of 1 pixel Pxy is set to 4 μm square on the substrate P, and the amount of 1 pixel is drawn with 2 pulses of the spot light SP, if 3σ The value is about 6nS, which means that the position of the pattern drawn along the drawing line SLn has a deviation of about 5 μm (to be precise, 4.8 μm) in the main scanning direction.

When the focal distance of the fθ lens system FT is set to fo, and the pulse interval distance of the spot light SP on the substrate P (1/2 of the spot diameter) is set to △Yp, it corresponds to the multi-faceted pulse interval distance △Yp The angle change Δθp of the mirror PM (reflecting surface) becomes Δθp≒ΔYp/fo. On the other hand, if the moving distance of the laser beam Bgb (spot light SPr) on the photoelectric conversion element DTo corresponding to the angle change △θp is set to △Yg, it is determined by the lens on the side of the beam receiving unit (beam receiving system) 60b The focal distance of the system GLb is Fgs, and the moving distance △Yg becomes △Yg≒△θp×Fgs. The generation accuracy of the origin time Tog of the origin signal SZn is ideally corresponding to the accuracy (resolution) less than 1/2 of the pulse spacing distance △Yp of the spot light SP, so the laser beam Bgb on the photoelectric conversion element DTo The scanning speed of the (spot light SPr) becomes about twice as fast as the scanning speed of the spot light SP on the substrate P. That is, it should be set as △Yg≒2. The relationship between △Yp. For this reason, in the present embodiment, the focal distance Fgs of the lens system GLb is set to approximately twice the focal distance fo of the fθ lens system FT, and of course it may be 2 times or more.

Fig. 12 shows another drawing unit with the same configuration as the drawing unit Un measured in Fig. 11, changing the focal distance Fgs of the lens system GLb to Fgs≒2×fo, and measuring the reproducibility in the same way as in Fig. 11 And got the result. The vertical axis and the horizontal axis of FIG. 12 are the same as those of FIG. 11, but 1 scale of the scale of the vertical axis of FIG. 12 is 2nS (5nS in FIG. 11). By making the scanning speed of the spot light SPr on the photoelectric conversion element DTo be about twice the scanning speed of the spot light SP on the substrate P, 3σ calculated based on the distribution of the deviation of each of the interval time △Tma~△Tmh The value becomes 1.3nS~2.5nS, which is about half the improvement compared with the case of Fig. 11. Therefore, in this case, if the diameter Φ of the spot light SP is set to 4 μm, the size of 1 pixel Pxy is set to a 4 μm square on the substrate P, and 1 pixel is drawn with 2 pulses of the spot light SP, then the drawing is drawn along The deviation of the position in the main scanning direction of the pattern drawn by the line SLn is halved to about 2.5 μm.

As described above, the beam Bga for the origin sensor projected on the reflecting surface RPa~RPh of the polygon mirror PM is set such that the dimension relative to the rotation direction of the reflecting surface RPa~RPh becomes a predetermined thickness (for example, the diameter is 1 ~2mm) or more parallel beams, thereby reducing the influence caused by the surface roughness (grinding marks, etc.) of each of the reflective surfaces RPa~RPh, and can accurately detect the average surface angle change. On the other hand, the diameter of the spot light SPr of the reflected beam Bgb condensed on the photoelectric conversion element DTo is based on the width of the light-receiving surfaces PD1 and PD2 in the scanning direction of the light beam, and the insensitive zone between the light-receiving surfaces PD1 and PD2. Set the width appropriately. In order to obtain the signal waveform as shown in Fig. 5[A], the diameter size of the spot light SPr in the scanning direction is set to be smaller than the smaller width size of the light receiving surfaces PD1, PD2 and larger than the width of the non-sensing zone. Therefore, the focal distance Fgs of the lens system GLb into which the reflected light beam Bgb is incident is set to be longer than the focal distance fo of the fθ lens system FT in a manner that satisfies this condition.

Furthermore, the intensity distribution in the cross-section of the beam Bga radiated from the semiconductor laser light source LDo shown in FIG. 4 is an ellipse with an aspect ratio of about 1:2. Therefore, it is preferable to make the long axis direction of the ellipse and the polygon mirror PM The rotation direction (main scanning direction) of each reflecting surface RPa~RPh is the same, and the minor axis direction of the ellipse is consistent with the direction of the rotation axis AXp of the polygon mirror PM. In this way, even if the height of each reflecting surface RPa~RPh of the polygon mirror PM (the size in the direction of the rotation axis AXp) is small, the light beam Bga can be effectively emitted as the reflected light beam Bgb, and can reach the photoelectric conversion element DTo The number of openings (NA) in the scanning direction of the reflected light beam Bgb is greater than the number of openings (NA) in the non-scanning direction, so the analysis in the scanning direction of the spot light SPr (the direction across the light-receiving surface PD1 and PD2 in Figure 5) can be improved , And make the contrast sharper.

In addition, as the photoelectric conversion element DTo, it can be used instead of comparing the magnitudes of the output signals STa and STb from the two light-receiving surfaces PD1 and PD2 to generate the origin signal SZn as shown in Figure 5. The signal level of the light-receiving surface of the shape is compared with the reference voltage to generate the type of origin signal SZn. In this type of situation, the reproducibility of the origin time Tog of the origin signal SZn has the possibility that the steeper the slope of the rising or falling part of the signal waveform (the shorter the response time), the better, so it is better to make the cross The scanning speed of the point light SPr of the slit-shaped light-receiving surface is faster than the scanning speed of the point light SP for drawing, and the point light SPr is condensed as small as possible by the lens system GLb to increase the intensity per unit area.

In addition, the origin detection sensor (lens system GLb, photoelectric conversion element DTo) of the present embodiment shown in FIG. 3 is a light beam for origin detection projected from a light source different from the drawing (processing) light beam LBn The reflected beam Bgb on the Bga polygon mirror PM is photoelectrically detected. However, in the arrangement relationship of FIG. 3, just after the reflecting surface RPa of the polygon mirror PM reaches the angular position of RPa', the drawing light beam LBn is not incident on the fθ lens system FT (blank period), but it can be incident The period to the lens system GLb. During the blank period, the light beam LBn for drawing is controlled so as not to enter the drawing unit Un by pulse oscillation of the light beam LB from the light source device LS or the control of the optical element OSn for selection. Therefore, even in the blank period, only during the period when the drawing light beam LBn can be incident on the lens system GLb, the optical element OSn for selection is turned on and the light beam LB is pulse-oscillated at the oscillation frequency Fa from the light source device LS. The photoelectric conversion element DTo receives the reflected light beam of the light beam LBn reflected by the polygon mirror PM. In the case of such a configuration, the drawing light beam LBn incident on the lens system GLb during the blank period can be used as the origin detection light beam.

In addition, the tendency of the deviation of the interval time △Tma~△Tmh shown in Fig. 12 and the tendency of the deviation of the interval time △Tma~△Tmh shown in Fig. 11 above are quite different if viewed on the order of nanoseconds. It is assumed that the reason lies in the fact that the angle error tendency of each vertex angle between the polygon mirror PM used in the actual measurement of the reproducibility of each of Fig. 11 and Fig. 12 is different. Like the actual measurement example shown in Figure 11 or Figure 12, the processing tolerance or eccentricity error tendency or degree of the polygon mirror PM may be different for each drawing unit Un (U1~U6), and the deviation of the interval time △Tma~△Tmh The error is also different for each drawing unit Un (U1~U6). Therefore, in this embodiment, in order to reduce the deviation error of the interval time △Tma~△Tmh caused by the processing tolerance or eccentricity error of the polygon mirror PM, or the shape deformation of the polygon mirror PM caused by temperature changes, etc. As a result, the delay time TD set from the origin time Tog of the origin signal SZn to the drawing start time point is adjusted for each of the reflecting surfaces RPa~RPh of the polygon mirror PM. In other words, the interval time △Tma~△Tmh of the origin time Tog of the origin signal SZn generated for each of the reflecting surfaces RPa~RPh of the polygon mirror PM is corrected by signal processing to make it equal to the polygon mirror PM The time for one revolution is roughly equal.

Fig. 13 shows a state in which a spot light SP with an average of 2 pulses per pixel is overlapped in the main scanning direction and the sub-scanning direction with 1/2 of the spot size Φ, and a continuous pattern of 5 pixels is drawn in the main scanning direction. Figure. In Fig. 13, the origin time Tog of the origin signal SZn generated for each of the reflecting surfaces RPa~RPh of the polygon mirror PM is set as the starting point, and the pattern drawing of 5 pixels starts after a fixed delay time TD . In addition, the tendency of the deviation (the deviation of the interval time ΔTma ~ ΔTmh) in the generation timing (origin time Tog) of the origin signal SZn in FIG. 13 is shown in the case of FIG. 12 as an example. As shown in FIG. 13, when the pattern of 5 pixels drawn by the spot light SP of the beam LBn scanned by the reflecting surface RPa of the polygon mirror PM is used as a reference, by using the other reflecting surfaces RPb~RPh of the polygon mirror PM The pattern of 5 pixels drawn by the spot light SP of the light beam LBn for each scanning has a deviation in the main scanning direction. Therefore, the edges of the depicted pattern that extend in the sub-scanning direction meander in pixel units (amount of 1 to 2 pixels). Regardless of the line width of the pattern to be drawn (the number of pixels in the main scanning direction), the number of meandering pixels corresponds to the deviation of the interval time △Tma~△Tmh. Therefore, when the size of 1 pixel is 4μm square on the substrate P, if a pattern with a minimum line width of 8μm (amount of 2 pixels) is drawn continuously in the sub-scanning direction, the exposed linear pattern It has been observed as a pattern that greatly meanders with the line width.

Fig. 14 is a graph obtained by schematically showing the characteristic graph of the actual measurement example in Fig. 12, and RPa/b~RPh/a on the horizontal axis respectively represent the positions between the reflecting surfaces of the horizontal axis in Fig. 12 (RPa→ RPb, RPb→RPc,...RPh→RPa), the vertical axis represents the same origin interval time △Tma~△Tmh(μS) as in Figure 12. The reference time Tsr in FIG. 14 is the time required for the rotation of 45° when the 8-sided polygon mirror PM is precisely rotated at a rotation speed of 38000 rpm, which becomes 197.368 μS. Furthermore, the times Tab, Tbc, Tcd, Tde, Tef, Tfg, Tgh, and Tha in FIG. 14 are the intervals of the center of the 3σ value that is three times the standard deviation shown in FIG. 12. There is also an error in the rotation speed of the polygon mirror PM during the actual measurement, so it is advisable to divide the total value of the interval time Tab, Tbc, Tcd, Tde, Tef, Tfg, Tgh, Tha by 8 and set the average value as the actual reference time Tsr '.

Therefore, in this embodiment, each of the origin interval time △Tma~△Tmh of the origin signal SZn output with the characteristics shown in Figure 14 is corrected by the delay circuit in a manner consistent with the reference time Tsr' . FIG. 15 is a timing diagram illustrating the generation state of the origin signal SZn' obtained by correcting the origin signal SZn. In FIG. 15, the time period from the origin time Tog generated corresponding to the reflecting surface RPa of the polygon mirror PM in the origin signal SZn to the origin time Tog generated corresponding to the next reflecting surface RPb is representatively shown in FIG. The state is corrected, but the other reflecting surfaces RPb~RPh are also corrected in the same way. The origin time Tog corresponding to each of the reflection surfaces RPa and RPb of the origin signal SZn is generated like the interval time Tha, Tab, Tbc... as shown in FIG. 14. Here, when the origin time Tog corresponding to the reflecting surface RPa is set as the starting point, the origin time Tog' of the corrected origin signal SZn' (corrected origin signal SZn') corresponding to the reflecting surface RPa is It is generated by adjusting the delay time ΔToa so that it becomes the reference time Tsr' from the origin time Tog' corresponding to the previous reflecting surface RPh. Furthermore, the origin time Tog' of the corrected origin signal SZn' corresponding to the reflecting surface RPb is adjusted so that the delay time Δ is the reference time Tsr' from the origin time Tog' corresponding to the previous reflecting surface RPa Tob is generated. Similarly, the origin time Tog' of the corrected origin signal SZn' corresponding to each of the other reflecting surfaces RPc~RPh is also relative to the corrected origin corresponding to each of the previous reflecting surfaces RPb~RPg. When the origin time Tog' of the point signal SZn' becomes the reference time Tsr', only the delay time △Toc, △Tod, △Toe, △Tof, △Tog, △Toh are corrected. The delay time △Toa~△Toh of each of the reflective surfaces RPa~RPh is calculated based on the difference between each of the interval times Tab~Tha specified as shown in Figure 14 and the reference time Tsr'.

FIG. 16 shows an example of the configuration of a correction circuit (correction unit) that inputs the origin signal SZn from the photoelectric conversion element DTo and generates a corrected origin signal SZn' (correction origin signal SZn') as shown in FIG. 15. The correction circuit is configured as a part of the drawing control device 200 shown in FIG. 6. In FIG. 16, the correction circuit has: a counting circuit 210, which counts the clock signal CCK set to a higher frequency (for example, 800MHz) than the frequency Fa (400MHz) of the clock signal CLK from the light source device LS; A bit register 212, which sets a preset value corresponding to each of the interval time Tab~Tha for the counting circuit 210; and a shifter control circuit 214, which controls the shifting action (temporary storage) of the shift register 212 Of choice). In addition, in this embodiment, a sensor 220 and a detection circuit 222 are provided. The sensor 220 photoelectrically detects the reflected light of the rotation reference mark Mcc shown in FIG. The signal of the detector 220 generates a logic level rotation pulse signal (a rotation of the polygon mirror PM is counted as 1 pulse) Sj. The shifter control circuit 214 outputs the shift signal Sff (address designation signal) starting from the reflecting surface RPa of the polygon mirror PM to the shift register 212 according to the rotation pulse signal Sj and the origin signal SZn. The shift register 212 corresponds to the 8 reflecting surfaces RPa~RPh and has 8 registers 212A. The 8 registers 212A are connected in a ring-shaped shift register and respond to the shift signal Sff The preset value held in each register is sequentially shifted to the adjacent register. The output from one of the eight registers 212A of the shift register 212 is applied to the counting circuit 210.

The counting circuit 210 is based on the origin time Tog of the origin signal SZn generated corresponding to the reflecting surface RPa in response to the pulse of the clock signal CCK and subtracts the value from the shift register 212 set in response to the reset signal RST The preset value (such as △Toa) generates a pulse-like origin signal SZn' when the count value becomes zero. The counting circuit 210 inputs the origin signal SZn' as the reset signal RST, and responds to the shift signal Sff to read after a fixed time (before the reference time Tsr') from the origin time Tog' of the origin signal SZn' Import and set a preset value (for example, ΔTob) from the shift register 212 of only 1 shift. With this action, the corrected origin signal SZn' output from the counter circuit 210 is the corrected roughly fixed reference time Tsr based on the interval time of each of the reflective surfaces RPa~RPh of the polygon mirror PM. 'Record the origin time Tog'.

Furthermore, the preset values memorized by each of the 8 registers 212A of the shift register 212 are stored in the memory portion of the drawing control device 200, and are read out from there to perform the preset. The interval time Tab~Tha shown in Fig. 14 and the reference time Tsr' are different according to the rotation speed VR of the polygon mirror PM. Therefore, for each different rotation speed VR, the characteristics as shown in Fig. 12 and Fig. 14 are measured in advance. The preset value corresponding to each of the delay time ΔToa~ΔToh corresponding to the reference time Tsr' of each rotation speed VR is determined, and stored in the memory part of the drawing control device 200 in the form of a table. Therefore, when the rotation speed VR of the polygon mirror PM is changed from a standard value (for example, 38000 rpm) during the drawing operation, the delay time △Toa~△Toh corresponding to the rotation speed VR of the polygon mirror PM after the change The setting value is read from the table of the memory part in the drawing control device 200 and set in the register 212A of the shift register 212. The set of preset values corresponding to the delay time △Toa~△Toh memorized in the table in the drawing control device 200 is based on, for example, the configuration of the polygon mirror PM under the condition of changing 2000 rpm each time such as 40,000 rpm, 38000 rpm, 36000 rpm, etc. The rotation speed VR is made from the data obtained from the actual measurement. The preset value of the delay time △Toa~△Toh corresponding to the rotation speed VR during the period can also be obtained by linear interpolation.

According to the above embodiment, by using the corrected origin signal SZn' for the control of the drawing start, the reproducibility of the drawing start point is improved, and the origin time Tog' of each of the reflecting surfaces RPa~RPh of the polygon mirror PM The deviation is reduced, so the deviation of the absolute position of the main scanning direction on the substrate P at the drawing start point is also reduced, and the quality of the drawn pattern is improved.

[Modification 1]

As shown in FIG. 1, if a plurality of drawing units Un are arranged adjacently, the temperature in each drawing unit Un will easily rise. The temperature rise can also be suppressed by the air conditioning or temperature adjustment of the drawing unit Un, but in order to reduce the noise (wind noise) generated when the polygon mirror PM is rotated at a high speed, a housing or a polygon mirror PM is provided for each drawing unit Un An outer cover is set around it, so there are cases where the air conditioning or temperature control does not work effectively. That is, it is difficult to satisfactorily suppress changes in air temperature around the polygon mirror PM or around the origin sensor (the light beam transmitting portion 60a and the light beam receiving portion 60b). If aluminum is used as the base material of the polygon mirror PM in order to reduce the weight, the state of the reflecting surface of the polygon mirror PM may deform in the sub-micron order depending on the degree of such temperature change. In addition, when the lens system GLa of the beam transmission unit (beam transmission system) 60a that generates the origin detection beam Bga is made of plastic (resin mold) to realize unitization with the semiconductor laser light source LDo, According to the change of the surrounding temperature, the light beam Bga toward the polygon mirror PM easily changes from the parallel state to a light beam with convergence or divergence. Therefore, the focus state of the spot light SPr of the reflected light beam Bgb condensed on the photoelectric conversion element DTo changes, and the reproducibility of the origin signal SZn decreases or the angle of the light beam Bga toward the polygon mirror PM is slightly shifted.

Therefore, in this modified example, a temperature sensor that precisely measures the temperature around the polygon mirror PM or around the origin sensor (beam transmitting part 60a, beam receiving part 60b) is provided, and the actual measurement is obtained in advance. The reproducibility (3σ value) of the origin signal SZn and the variation coefficient of the origin interval △Tma~△Tmh (or the interval time Tab~Tha in Figure 14) with respect to the temperature change, according to the temperature measured by the temperature sensor And the preset value corresponding to each of the delay time ΔToa~ΔToh set in the shift register 212 of FIG. 16 is corrected. Thereby, the deviation of the starting point of the drawing pattern in the main scanning direction due to the temperature change of the drawing unit Un can be reduced.

[Modification 2]

Fig. 17 is a diagram showing the configuration of the origin sensor of Modification 2, and is a view of the polygon mirror PM in the drawing unit Un, the optical axis AXf of the fθ lens system FT, and the configuration of the origin sensor in the XY plane A view of the arrangement of the light beam transmitting section 60a and the light beam receiving section 60b. In FIG. 17, the drawing beam LBn is projected toward one reflective surface RPa of the reflective surface RP of the polygon mirror PM, and the reflective surface RPb of the reflective surface RPa of the polygon mirror PM is projected from The laser beam (beam for origin detection) Bga of the beam transmitting unit 60a. In addition, the angular position of the reflective surface RPa in FIG. 17 indicates a state where the spot light SP of the drawing light beam LBn is located immediately before the drawing start point of the drawing line SLn. Here, the reflecting surface RP (RPa) of the polygon mirror PM is arranged so as to be located on the entrance pupil surface orthogonal to the optical axis AXf of the fθ lens system FT. Strictly speaking, the principal ray of the light beam LBn incident on the fθ lens system FT becomes the angular position of the reflective surface RP (RPa) at the moment when it is coaxial with the optical axis AXf, and the principal ray of the light beam LBn from the mirror M23 toward the polygon mirror PM The position where the light crosses the optical axis AXf sets the reflecting surface RP (RPa). In addition, the distance from the principal surface of the fθ lens system FT to the surface of the substrate P (the condensing point of the spot light SP) is the focal distance fo.

The light beam Bga from the light beam sending portion 60a is projected to the reflecting surface RPb of the polygon mirror PM as a parallel light beam in the wavelength region where the photosensitive functional layer of the substrate P is non-photosensitive by the lens system GLa same as in FIG. 4 . The reflected beam Bgb of the laser beam Bga reflected on the reflective surface RPb faces a mirror (reflective optical member) MRa having a reflective surface perpendicular to the XY plane. The reflected light beam Bgc of the light beam Bgb reflected by the mirror MRa is again projected toward the reflection surface RPb of the polygon mirror PM. The reflected light beam Bgd of the light beam Bgc reflected on the reflective surface RPb is received by the light beam receiving portion 60b. The light beam receiving part 60b is located at the moment when the reflecting surface RPb (and other reflecting surfaces RP) of the polygon mirror PM becomes a specific angular position in the XY plane, so that the light beams Bga, Bgb, Bgc, and Bgd travel as shown in Figure 17, and the light beams receive light. The part 60b outputs a pulse-shaped origin signal SZn. In FIG. 17, the light beam Bga is simply expressed as a line, but in reality, it is set to be a parallel light beam having a predetermined width in the rotation direction of the reflection surface RP of the polygon mirror PM in the XY plane. Similarly, in Fig. 17 the light beam Bgd is simply expressed as a line, but actually becomes a parallel light beam having a predetermined width in the XY plane. The light beam Bgd responds to the rotation of the polygon mirror PM and responds to the light beam receiving portion 60b as an arrow Aw Normally scan. 4, the light beam receiving portion 60b has: a photoelectric conversion element DTo, which outputs an origin signal SZn when receiving the light beam Bgd; and a lens system GLb, which condenses the light beam Bgd on the photoelectric conversion element DTo into a spot light SPr .

In this modification 2, as shown in FIG. 17, it is configured as follows: a mirror MRa is used, and the light beam Bga for origin detection is received by the photoelectric conversion element DTo and reflected twice on the reflecting surface RP (RPb) of the polygon mirror PM. The spot light SPr of the light beam Bgd. Therefore, the scanning speed Vh of the spot light SPr on the light-receiving surfaces PD1 and PD2 and the origin detection light beam Bga can be reflected once on the reflecting surface RP (RPb) of the polygon mirror PM and received by the photoelectric conversion element DTo. Figure 4 Compared with the situation, it is more than doubled. Thereby, compared with the scanning speed Vsp of the drawing light beam LBn (spot light SP) on the substrate P, the scanning speed Vh of the origin detection light beam Bgd (spot light SPr) on the photoelectric conversion element DTo can be increased to 2 The reproducibility of the origin signal SZn can be improved in the same way as in the first embodiment. However, in this modified example 2, it is not necessary to make the focal distance Fgs of the lens system GLb provided in the light beam receiving portion 60b more than twice the focal distance fo of the fθ lens system FT, and even the same focal distance can be set to point The scanning speed Vh of the light SPr is twice the scanning speed Vsp of the spot light SP.

Moreover, in this modification 2, the light beam Bga for origin detection is projected on the reflective surface RPb before the reflective surface RPa of the polygon mirror PM to which the light beam LBn for drawing is projected. Therefore, in the case of the origin sensor as shown in FIG. 17, the setting is performed as follows: the reflecting surface RPa is set so that the point light SP of the drawing light beam LBn is located slightly forward of the drawing start point of the drawing line SLn At the moment of the angle of, the origin signal SZn from the light beam receiving portion 60b of FIG. 17 becomes the origin time Tog. In this way, even if it is a configuration that uses the different reflecting surface reflection and drawing light beams LBn and origin detection light beam Bga of the polygon mirror PM, it is possible to generate the corrected origin signal SZn' as in the first embodiment, thereby enabling Reduce the deviation of the starting point of the drawing pattern in the main scanning direction.

[Second Embodiment]

In the second embodiment, the spot light SP of the light beam LBn projected from the drawing unit Un is used to scan the reference pattern formed on the outer peripheral surface of the rotating drum DR shown in FIG. The photoelectric signal obtained from the detection of the reflected light generated by the reference pattern, confirm the reproducibility of the origin signal SZn or the origin interval time △Tma~△Tmh (or the interval time Tab~Tha in Figure 14), or set the delay time Toa ~Toh. Furthermore, for example, it is disclosed in International Publication No. 2015/152217 that a reference pattern is provided on the outer peripheral surface of the rotating drum DR, and the light detector DTc in the drawing unit Un is used to detect the regular reflection light generated when the reference pattern is scanned by the spot light SP. The composition.

18 is a diagram showing an example of the waveform of the photoelectric signal Sv generated from the photodetector DTc when the line and gap-like reference patterns PTL1 and PTL2 formed on the outer peripheral surface of the rotating drum DR are scanned by the spot light SP. The reference pattern PTL1 is a low-reflectivity linear pattern with a line width of 20μm in the main scanning direction of the spot light SP and extending in the sub-scanning direction. The reference pattern PTL2 is a line pattern with a line width of 20μm in the main scanning direction and extending in the sub-scanning direction. Linear pattern with high reflectivity. If such reference patterns PTL1 and PTL2 are scanned by the spot light SP, the intensity of the regular reflection light generated from the reference pattern PTL1 becomes lower, and the intensity of the regular reflection light generated from the reference pattern PTL2 becomes higher. Since the fθ lens system FT is telecentric, the regular reflection light from the reference patterns PTL1 and PTL2 travels backward along the optical path of the drawing beam LBn in FIG. 2 and reaches the polarization beam splitter BS1. Although not shown in FIG. 2, a condenser lens is provided for condensing the regular reflection light (the same parallel light beam as the light beam LBn) transmitted through the polarizing beam splitter BS1 on the photodetector DTc. Thereby, the outer peripheral surface of the substrate P or the rotating drum DR is conjugated with the light-receiving surface of the photodetector DTc, and a conjugate image of the spot light SP projected on the reference patterns PTL1 and PTL2 is formed on the light-receiving surface of the photodetector DTc. Therefore, the signal Sv from the photodetector DTc becomes a low level during the projection of the reference pattern PTL1 by the spot light SP, and becomes a high level during the projection of the reference pattern PTL2.

Using the clock signal CLK from the light source device LS that pulses the spot light SP to emit light, or the sampling clock signal obtained by multiplying the clock signal CLK, the waveform change of the signal Sv from the photodetector DTc is digitally converted and then memorized And analyze, according to the origin time Tog of the origin signal SZn (or the origin time Tog' of the corrected origin signal SZn') as the reference point light SP scanning position to measure the reference pattern PTL1 The edge position of PTL2 extending in the sub-scanning direction.

Fig. 19 shows an example of the circuit configuration for digitally sampling the waveform of the signal Sv from the photodetector DTc. The level of the signal Sv is digitally converted; the multiplication section 241 generates a sampling clock signal (hereinafter referred to as the clock signal) CLK2 that doubles the frequency Fa of the clock signal CLK from the light source device LS by 2 times; the waveform memory section ( Memory part) 242, which is responsive to the clock signal CLK2 and memorizes the data obtained by digital conversion by the A/D conversion part 240; the address generating part 244, which is based on the corrected origin signal SZn' and the clock signal CLK2 The memory address value generated when the waveform memory portion 242 stores data; and the waveform analysis portion 246, which includes a CPU that reads and analyzes the waveform data of the signal Sv stored in the waveform memory portion 242. The information analyzed by the waveform analysis unit 246 is sent to the drawing control device 200 in FIG. 6 and used for the reproducibility (3σ value) of the origin signal SZn' or the confirmation of the interval time Tab~Tha, or the delay time Toa~ Toh's correction.

FIG. 20 is a timing diagram showing an example of a deviation in the generation timing of the origin time Tog' (or origin time Tog) of the origin signal SZn' (or origin signal SZn) using the circuit configuration of FIG. 19; In this embodiment, on the outer peripheral surface of the rotating drum DR, a position in the sub-scanning direction (Y direction) corresponding to the vicinity of the scanning start point of the drawing line SLn of the drawing unit Un to be confirmed is formed as shown in FIG. 16 Reference patterns PTL1 and PTL2. In this embodiment, the rotation angle of the rotating drum DR is set so that the reference patterns PTL1 and PTL2 are located on the drawing line SLn and made to stand still.

As shown in FIG. 20, immediately after the fixed delay time ΔTD from the origin time Tog' of the corrected origin signal SZn', the light beam LB from the light source device LS shown in FIG. 6 is pulse-oscillated at the oscillation frequency Fa , And began to describe. In addition, just before the pulse oscillation of the light beam LB starts, the optical element OSn for selection corresponding to the drawing unit Un to be the object is also turned on. While the optical element OSn for selection is turned on and the light beam LB is supplied to the target drawing unit Un as the light beam LBn, the spot light SP of the light beam LBn is set to traverse the range of the reference patterns PTL1 and PTL2. During the on-state, the light beam LB from the light source device LS continuously oscillates at the frequency Fa. When the spot light SP scans the surface of the rotating drum DR immediately after the delay time ΔTD, the photoelectric signal Sv from the photodetector DTc changes in level with a waveform as shown in FIG. 20. The address generating unit 244 delays the time Tu1 after the time △Tu from the origin time Tog', and generates an address value that gradually increases in response to the clock pulse of the clock signal CLK2. The waveform memory unit 242 is connected to the designated The address value sequentially stores the digital value from the A/D conversion unit 240 (the value corresponding to the level of the signal Sv). Here, the delay time ΔTu is set as ΔTu>ΔTD, and is set as the time before the spot light SP reaches the reference patterns PTL1 and PTL2.

With the address generation unit 244 and the waveform memory unit 242, the waveform of the signal Sv will be changed during the fixed time from time Tu1 to time Tu2, that is, the period during which the spot light SP scans the distance including the reference patterns PTL1 and PTL2 The data is stored in the waveform memory part 242 with the time resolution of the clock signal CLK2. The above-mentioned waveform memory operation is performed every time the light beam LBn is scanned by a designated reflecting surface RP (for example, RPa) of the polygon mirror PM. The waveform memory section 242 stores a plurality of borrowings. Waveform data from the time Tu1 to the time Tu2 of the photoelectric signal Sv generated by the spot light SP scanned by the same reflecting surface RP of the polygon mirror PM. The waveform analysis unit 246 analyzes the plurality of stored waveform data, and confirms whether the reproducibility of the origin time Tog' of the origin signal SZn' is within a predetermined specification. For this reason, the waveform analysis unit 246 identifies the rising or falling position (address position) corresponding to each edge position of the reference patterns PTL1 and PTL2 in the waveform change of the signal Sv, and obtains each reference pattern PTL1 (low reflectivity). ) Midpoint position, and then find the average position CTu (address position) of its isomidpoint position. The address value of one waveform data stored in the waveform memory 242 corresponds to the clock pulse of the clock signal CLK2, so the time from time Tu1 to the average position CTu can be based on the period of the clock signal CLK2 and from time Tu1 The product of the number of addresses up to the average position CTu is converted to calculate the time ΔTPc from the origin time Tog' of the origin signal SZn' to the average position CTu. The waveform analysis unit 246 performs this analysis on each of the plurality of stored waveform data, and calculates a plurality of times ΔTPc. The waveform analysis unit 246 obtains a 3σ value based on the standard deviation value σ of the deviations of a plurality of estimated times ΔTPc, and sends the 3σ value to the drawing control device 200.

In addition, in order to confirm whether each of the interval time Tab~Tha of the origin time Tog' of the corrected origin signal SZn' generated corresponding to each reflecting surface RPa~RPh of the polygon mirror PM is corrected to the reference time Tsr', and Add a counting circuit that counts the clock signal CLK2 to the circuit configuration of FIG. 19, for example, the origin time Tog' generated by the corrected origin signal SZn' corresponding to the reflecting surface RPa of the polygon mirror PM and the corresponding reflection The interval time of the origin time Tog′ generated by a reflecting surface RPb under the surface RPa is measured multiple times, and the average value is calculated and sent to the drawing control device 200. The interval time between other reflecting surfaces is also measured in the same way, and the average value of the calculated interval time is sent to the drawing control device 200. The drawing control device 200 confirms whether each of the sent interval time Tab~Tha is within the allowable range with respect to the reference time Tsr', and when there is an error above the allowable range, it corrects the shift register 212 in FIG. 16 Set delay time △Toa~△Toh.

According to the above second embodiment, it is possible to suppress the deviation of the drawing start position caused by the time-dependent variation of the corrected origin signal SZn' (or the origin signal SZn before the correction), and the accuracy can be stabilized for a long time Realize pattern drawing. Furthermore, in this embodiment, the reference patterns PTL1 and PTL2 formed on the outer peripheral surface of the rotating drum DR are used to confirm the reproducibility of the origin signal SZn' or the interval Tab~Tha, but the reference set on the substrate P can also be detected Patterns PTL1, PTL2. In addition, a single reference sheet (for example, an extremely thin glass sheet or stainless steel sheet with the same thickness as the substrate P, flexibility, and less deformation) formed with reference patterns PTL1 and PTL2 can also be wound And fixed around the rotating drum DR.

[Third Embodiment]

FIG. 21 is a diagram illustrating the test exposure method used to verify the accuracy of the corrected origin signal SZn' (or the origin signal SZn before correction) of the third embodiment. In this embodiment, 1 A drawing unit Un is arranged in a matrix in the main scanning direction and the sub-scanning direction on the substrate P on which the photosensitive layer is formed, and a plurality of rectangular test patterns Tpt are exposed. However, in this embodiment, the test pattern Tpt exposed to line MPa among the plurality of test patterns Tpt arranged in the sub-scanning direction is controlled in such a way that only the reflecting surface RPa of the polygon mirror PM is used for drawing, and the exposure is controlled in the line The test pattern Tpt of MPb is controlled in such a way that only the reflecting surface RPb of the polygon mirror PM is used for drawing. In the same manner below, the test pattern Tpt exposed to each of the rows MPc~MPh is controlled by drawing using any one of the reflecting surfaces RPc~RPh of the polygon mirror PM, respectively. That is, in order to expose each test pattern Tpt using the spot light SP of the light beam LBn reflected by only one of the designated reflecting surfaces during one revolution of the polygon mirror PM, the substrate P is exposed at 1/8 of the conveying speed during normal exposure The speed of transportation. Furthermore, it is not necessary to arrange a plurality of test patterns Tpt in the main scanning direction in the rows MPa~MPh, but to confirm the test patterns Tpt for each position (area) in the main scanning direction of the drawing line SLn for scanning the spot light SP The shape changes to be configured.

The tested and exposed substrate P can also be set to be obtained by neatly attaching a single piece of PEN film, an extremely thin glass sheet or a stainless steel sheet to the outer peripheral surface of the rotating drum DR with less expansion and contraction. After the test-exposed substrate P is subjected to development processing or etching processing, an inspection device or the like is used to enlarge and observe the formation state of the edge portions Ef and Et of the test pattern Tpt extending in the sub-scanning direction. When the edge portions Ef and Et of the test pattern Tpt are deviated, for example, as shown in Fig. 13, the reproduction of the origin time Tog' of the corrected origin signal SZn' corresponding to the reflecting surface of the polygon mirror PM depicting the test pattern Tpt Sexual deterioration.

Furthermore, as shown in FIG. 21, the group of 8 rows MPa~MPh of the test pattern Tpt drawn by each of the 8 reflecting surfaces RPa~RPh of the polygon mirror PM is repeatedly formed in the sub-scanning direction. And, for example, specify the center position of the first test pattern Tpt in the first row MPa and the second row MPa separated from the first row MPa in the sub-scanning direction, and the first test pattern Tpt in the main scan A straight line Lcc connecting the center positions of the second test pattern Tpt at the same position in the direction, and the center position between the edge portions Ef and Et of each of the test patterns Tpt arranged in the sub-scanning direction along the straight line Lcc and The position error of the main scanning direction of the straight line Lcc is △Ytt. The position error ΔYtt becomes approximately the same amount when each of the interval time Tab~Tha of the correction origin signal SZn' is precisely adjusted to the reference time Tsr'. However, in the case where the measured position error △Ytt has a deviation in the lines MPb~MPh, it means the correction deviation of the interval time Tab~Tha from the reference time Tsr'. That is, the interval time Tab~Tha of the origin signal SZn before correction changes. By analyzing the position error ΔYtt, the change of the interval time Tab~Tha can be inferred. Therefore, the drawing control device 200 corrects the delay time Toa~Toh and sets the shift register 212.

As described above, according to the present embodiment, the pattern (test pattern) exposed on the substrate P by only one reflecting surface of the polygon mirror PM is inspected, so that the origin signal SZn' (or the original before correction) can be confirmed and corrected. The reproducibility of the origin time Tog' (or origin time Tog) generated by each of the reflective surfaces RPa~RPh of the point signal SZn). Furthermore, it is also possible to confirm the variation of the deviation of the interval time Tab~Tha between the reflecting surfaces RPa~RPh of the polygon mirror PM.

[Modifications of the third embodiment]

In the case of test exposure as shown in Figure 21, the rotating drum DR must be precisely rotated at a predetermined speed (1/8 of the normal speed), and during the test exposure, the rotating drum DR must also be made not to the central axis AXo A slight displacement in the direction of extension (main scanning direction). However, it is difficult to suppress the position variation of the rotating drum DR in the main scanning direction to the micron level or sub-micron level.

Therefore, in this modified example, as shown in FIG. 22, the end of the direction in which the central axis AXo extends on the outer peripheral surface of the rotating drum DR is provided with a continuous linear reference pattern PTL3 in the circumferential direction. Furthermore, the following components are provided: a pattern detector DXa, which is set on the extension line of the odd-numbered drawing lines SL1, SL3, SL5 in the Y-axis direction (main scanning direction) and equipped with the detection area Axv of the detection reference pattern PTL3; and The pattern detector DXb is set on the extension line of the even-numbered drawing lines SL2, SL4, SL6 in the Y-axis direction (main scanning direction), and has a detection area Axv of the detection reference pattern PTL3. The pattern detectors DXa and DXb can measure a small displacement in the Y-axis direction in the detection area Axv of the linear reference pattern PTL3 at any time at the sub-micron level. In addition, when the reference pattern PTL3 is not provided on the outer peripheral surface of the rotating drum DR, it is also possible to form a reference plane orthogonal to the central axis AXo on the end face of the rotating drum DR in the direction in which the central axis AXo extends. Or optical non-contact gap sensors (linear sensors) GSa and GSb measure the displacement of the reference plane in the Y-axis direction. When viewed in the XZ plane orthogonal to the central axis AXo, the measurement position of the gap sensor GSa is set to be the same as the orientation of the odd-numbered drawing lines SL1, SL3, SL5. When viewed in the XZ plane, the gap The measurement position of the sensor GSb is set to be the same as the orientation of the even-numbered drawing lines SL2, SL4, SL6.

During the test exposure as shown in Figure 21, the pattern detectors DXa, DXb or the gap sensors GSa, GSb are used to measure the rotating drum DR (substrate The value of the position displacement in the Y-axis direction of P) is stored in the drawing control device 200, for example. Moreover, when measuring the positional relationship of the test pattern Tpt exposed in a matrix on the substrate P by an inspection device or the like, the measured value of the test pattern Tpt in the Y direction (main scanning direction) is corrected by the value of the stored positional displacement. Thereby, the error caused by the slight position change of the rotating drum DR (substrate P) in the Y-axis direction generated during the test exposure can be offset, and the reflecting surface RPa corresponding to the polygon mirror PM can be inspected with high precision. The reproducibility of the corrected origin signal SZn' (or the origin signal SZn before the correction) generated by each of the RPh, and the origin interval time between the reflecting surface RPa~RPh of the polygon mirror PM can be checked with high precision. Change of Tab~Tha deviation.

[Fourth Embodiment]

Fig. 23 is a view showing a partial cross-section of the rotating drum DR of the fourth embodiment. In this embodiment, a small opening 50J (can also be a recessed portion) is provided in a part of the outer peripheral surface of the rotating drum DR, and the light-receiving surfaces PD1 and PD2 are used to vertically receive the drawing beam from the drawing unit Un. In the LBn method, the photoelectric conversion element DTo is set as shown in FIG. 5. In this embodiment, instead of detecting the regular reflection light from the reference patterns PTL1 and PTL2 on the outer peripheral surface of the rotating drum DR as described above in FIG. 20, the photoelectric conversion element DTo provided on the rotating drum DR directly detects the origin. Use the beam Bgb (or the drawing beam LBn) to measure the reproducibility of the corrected origin signal SZn' (or the origin signal SZn before correction) or the deviation of the origin interval time Tab~Tha.

In the first embodiment shown in Fig. 3 above, the origin detection sensor (lens system GLb, photoelectric conversion element DTo) detects the origin of the light source projected from a light source different from the drawing (processing) light beam LBn The reflected light beam Bgb of the polygon mirror PM of the light beam Bga is used for photoelectric detection. However, in the arrangement relationship of FIG. 3, after the reflective surface RPa of the polygon mirror PM becomes the angular position of RPa', the reflected light beam Bgb reflected by the reflective surface RPa enters the fθ lens system FT. The reflected light beam Bgb incident on the fθ lens system FT can be condensed on the image surface side (rotating cylinder DR side) of the fθ lens system FT like the drawing light beam LBn. Therefore, in this embodiment, the photoelectric conversion element DTo installed on the rotating drum DR as shown in FIG. 23 is used to detect the reflected light beam Bgb that is scanned by the polygon mirror PM and enters the origin detection light beam Bga of the fθ lens system FT. . In this embodiment, in the state where the substrate P is not supported by the rotating drum DR or the transparent area of the substrate P is supported by the outer peripheral surface of the rotating drum DR, the photoelectric conversion element DTo provided on the rotating drum DR is performed. Measurement. In this embodiment, in the state where the rotating drum DR is stopped, the photoelectric conversion element DTo can receive both the origin detection light beam Bgb and the drawing light beam LBn. In this case, the scanning speed of the drawing light beam LBn across the photoelectric conversion element DTo of FIG. 23 is equal to the scanning speed of the origin detection light beam Bgb. Therefore, for example, using the multiplied clock signal CCK as shown in FIG. 19, the point light of the origin detection beam Bgb is located at the center of the light-receiving surface of the photoelectric conversion element DTo in FIG. 23 and the corrected origin signal The interval time between the origin time Tog' of SZn' (or the origin time Tog of the origin signal SZn before correction) is timed, so that the corrected origin signal SZn' (or the origin signal before correction) can be detected SZn) accuracy (reproducibility, deviation of the time between origins Tab~Tha).

AXo‧‧‧Central axis

AXp‧‧‧Rotation axis

DR‧‧‧Rotating drum

EX‧‧‧Exposure device (pattern drawing device)

FT‧‧‧fθ lens system (scanning lens for drawing)

IM1~IM6‧‧‧Entrance mirror

LS‧‧‧Light source device (pulse light source device)

M1~M12‧‧‧Mirror

M20~M24‧‧‧Mirror

OS1~OS6‧‧‧Optical components for selection

P‧‧‧Substrate (irradiated body)

PM‧‧‧Polygon mirror

RP‧‧‧Reflecting surface

SL1~SL6‧‧‧Drawing line

TR‧‧‧Absorber

U1~U6‧‧‧Drawing unit

X, Y, Z‧‧‧direction

Claims (23)

A beam scanning device that projects a processing beam to each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, so that the processing beam reflected by each of the plurality of reflecting surfaces passes through a scanning optical system Scanning on the irradiated body, and equipped with: an origin detection unit, which generates an origin signal every time each of the plurality of reflecting surfaces of the rotating polygon mirror becomes a predetermined predetermined angle; and a correction unit, which is based on The change in the rotation speed of the rotating polygon mirror calculates a correction value, and generates a correction origin signal corrected by the calculated correction value. The correction value is generated corresponding to each of the plurality of reflecting surfaces. The correction value of the deviation of the time interval of the origin signal. For example, the light beam scanning device of the first item of the scope of patent application is further provided with a control unit which controls the timing of the projection of the processing beam toward the irradiated body based on the corrected origin signal. For example, the light beam scanning device of the first item of the scope of patent application, wherein the origin detection part is provided with: a photodetector, which receives the reflected light beam of the detection light beam projected to the reflecting surface of the rotating polygon mirror and generates the origin signal; and A condensing optical system that condenses the reflected light beam of the detection beam into a light spot on the photodetector, and makes the scanning speed of the light spot traversing the photodetector by the rotation of the rotating polygon mirror , Faster than the scanning speed of the processing beam on the irradiated body. A beam scanning device that projects a processing beam to each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, so that the processing beam reflected by each of the plurality of reflecting surfaces passes through a scanning optical system Scanning on the irradiated body, and equipped with: an origin detection unit, which generates an origin signal every time each of the plurality of reflecting surfaces of the rotating polygon mirror becomes a predetermined predetermined angle; and a correction unit, which generates The corrected origin signal corrected by the correction value, the correction value is corresponding to the corresponding The correction value of the deviation amount of the time interval of the origin signal generated by each of the plurality of reflecting surfaces; the origin detection unit is equipped with: a photodetector, which receives and projects to the reflecting surface of the rotating polygon mirror for detection The reflected light beam of the light beam generates the origin signal; and a condensing optical system, which condenses the reflected light beam of the detection light beam on the photodetector into a light spot, and causes the horizontal rotation by the rotation of the rotating polygon mirror The scanning speed of the light spot passing through the photodetector is faster than the scanning speed of the processing beam on the irradiated body; the condensing optical system includes: a reflective optical member, which rotates the detection beam by the multi-faceted The first reflected light beam initially reflected by the reflecting surface of the mirror is reflected to the reflecting surface of the rotating polygonal mirror; and an optical element which makes the second reflected light beam reflected for the second time by the reflecting surface of the rotating polygonal mirror incident and enters the photoelectric The detector condenses light into a light spot. For example, the light beam scanning device in the scope of the patent application, wherein the correction part uses the rotation time corresponding to one revolution of the rotating polygon mirror obtained from the interval of the origin signal generation time divided by the rotation The reference interval time derived from the number of reflecting surfaces of the polygon mirror is set to a correction value corresponding to the deviation. A beam scanning device that projects a processing beam to each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, so that the processing beam reflected by each of the plurality of reflecting surfaces passes through a scanning optical system Scanning on the irradiated body, and equipped with: an origin detection unit, which generates an origin signal every time each of the plurality of reflecting surfaces of the rotating polygon mirror becomes a predetermined predetermined angle; and a correction unit, which generates The corrected origin signal corrected by the correction value is a correction value corresponding to the deviation of the time interval of the origin signal generated corresponding to each of the plurality of reflecting surfaces; the origin detection unit has: A photodetector, which receives the reflected beam of the detection beam projected to the reflecting surface of the rotating polygon mirror and generates the origin signal; and a condensing optical system, which causes the reflected beam of the detection beam to be on the photodetector Condensed light into a light spot, and the rotation of the rotating polygon mirror The scanning speed of the light spot traversing the photodetector is faster than the scanning speed of the processing beam on the irradiated body; the correction part is obtained by using the interval from the origin signal generation time The reference interval time obtained by dividing the rotation time corresponding to one revolution of the rotating polygon mirror by the number of reflecting surfaces of the rotating polygon mirror is obtained, and the correction value corresponding to the deviation is set. For example, the beam scanning device of any one of items 3, 4, and 6 of the scope of patent application, wherein the scanning optical system has the processing beam reflected by each of the plurality of reflecting surfaces of the rotating polygon mirror in the The light condensed on the irradiated body is the refractive power of the light spot. The condensing optical system includes an optical element that has a refractive power lower than that of the scanning optical system and condenses the reflected light beam of the detection light beam. Light. For example, the light beam scanning device of the 7th item of the scope of patent application, wherein the focal distance corresponding to the refractive power of the optical element of the condensing optical system is made longer than the focal distance corresponding to the refractive power of the scanning optical system. A pattern drawing device that projects a drawing light beam to each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, so that the drawing light beam reflected by each of the plurality of reflecting surfaces passes through the scanning The optical system scans the irradiated body, and draws a pattern on the irradiated body, and is equipped with an origin detection unit, which is used whenever each of the plural reflecting surfaces of the rotating polygon mirror becomes a predetermined predetermined angle Generating an origin signal; a drawing control unit, which sets a predetermined delay time from the generation of the origin signal to the start time point of pattern drawing by the drawing light beam; and a correction unit, which is based on the plurality of Each of the reflecting surfaces becomes a correction value corresponding to the deviation of the time interval of the predetermined angle, and the delay time set by the drawing control unit is corrected for each of the plurality of reflecting surfaces. For example, the pattern drawing device of item 9 of the scope of patent application, wherein the origin detection part is provided with: a photodetector, which receives the reflected light beam of the detection light beam projected to the reflecting surface of the rotating polygon mirror and generates the origin signal; and A condensing optical system that condenses the reflected light beam of the detection beam into a light spot on the photodetector, and makes the scanning speed of the light spot traversing the photodetector by the rotation of the rotating polygon mirror , Faster than the scanning speed of the drawing beam on the irradiated body. For example, the pattern drawing device of item 10 of the scope of patent application, wherein the scanning optical system has the drawing beam reflected by each of the plurality of reflecting surfaces of the rotating polygon mirror to condense the light on the irradiated body. For the refractive power of a point, the condensing optical system includes an optical element that has a refractive power lower than that of the scanning optical system and condenses the reflected light beam of the detection light beam. For example, the pattern drawing device of item 11 of the scope of patent application, in which the focal distance corresponding to the refractive power of the optical element of the condensing optical system is made longer than the focal distance corresponding to the refractive power of the scanning optical system. For example, the pattern drawing device of item 10 of the scope of patent application, wherein the condensing optical system includes: a reflective optical member that reflects the first reflected light beam initially reflected by the reflecting surface of the rotating polygon mirror to the rotating polygon The reflecting surface of the mirror; and an optical element, which makes the second reflected light beam reflected by the reflecting surface of the rotating polygon mirror incident for the second time, and condenses the light into a light spot on the photodetector. For example, the pattern drawing device of any one of the tenth to thirteenth items in the scope of the patent application, wherein the correcting part is calculated based on the interval of the origin signal generation time corresponding to the rotation of the rotating polygon mirror. The reference interval time obtained by dividing the rotating time by the number of reflecting surfaces of the rotating polygonal mirror, and setting the correction value corresponding to the deviation. A pattern drawing device, which is based on a rotating polygon mirror that rotates around a rotation axis Each of the plurality of reflecting surfaces projects a light beam for drawing, and the light beam for drawing reflected by each of the plurality of reflecting surfaces passes through the scanning optical system to scan on the substrate supported by the support member, and draw a pattern on the substrate , And equipped with: an origin detection unit, which generates an origin signal whenever each of the plurality of reflecting surfaces of the rotating polygon mirror becomes a predetermined predetermined angle; a drawing control unit, which will generate an origin signal from the origin After a predetermined delay time, it is set as the starting time point of pattern drawing by the drawing light beam; the correction part is based on the correction value corresponding to the deviation of the time interval when each of the plurality of reflecting surfaces becomes the predetermined angle , Correcting the delay time set by the drawing control section for each of the plurality of reflecting surfaces; and a measuring section, which measures automatically when scanning the reference pattern formed on the support member or the substrate with the drawing beam The time between the generation time point of the reflected light generated by the reference pattern and the generation time point of the origin signal, and the correction value corresponding to the deviation is obtained. For example, the pattern drawing device of item 15 of the scope of patent application, wherein the measuring part has a photodetector, and the photodetector receives the reflected light generated from the reference pattern through the scanning optical system and the rotating polygon mirror, and outputs The photoelectric signal corresponding to the change in the reflectivity of the reference pattern. For example, the pattern drawing device of the 16th patent application, wherein the scanning optical system condenses the drawing light beam on the substrate into a point light, and the drawing light beam is generated by the point light using the rotating polygon mirror In the scanning direction, the spot light is supplied by a light source device with pulsed oscillation in a period where the spot light partially overlaps. For example, the pattern drawing device of item 17 in the scope of patent application, wherein the measuring part has a waveform memory part, and the waveform memory part measures the waveform of the photoelectric signal from the photodetector at a higher frequency than the pulse oscillation frequency of the light source device Change sampling. A pattern drawing device that projects a drawing light beam to each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, so that the drawing light beam reflected by each of the plurality of reflecting surfaces passes through the scanning The optical system scans on the substrate supported by the supporting member, and draws a pattern on the substrate, and is equipped with an origin detection section, which is designed whenever each of the plurality of reflecting surfaces of the rotating polygon mirror becomes a predetermined predetermined angle The origin signal is generated when the origin signal is generated; the drawing control unit sets a predetermined delay time from the generation of the origin signal as the start time point of pattern drawing by the drawing beam; the correction unit is based on the plurality of Each of the reflecting surfaces becomes the correction value corresponding to the deviation of the time interval of the prescribed angle, and the delay time set by the drawing control unit is corrected for each of the plurality of reflecting surfaces; and the measuring unit is provided with the The photoelectric conversion element of a part of the supporting surface of the supporting member, and by measuring the time between the generation time point of the photoelectric signal obtained when the photoelectric conversion element is scanned by the drawing beam and the generation time point of the origin signal, Find the correction value corresponding to the deviation. For example, the pattern drawing device of item 19 of the scope of patent application, wherein the origin detection part is provided with: a photodetector, which receives the reflected light beam of the detection light beam projected to the reflecting surface of the rotating polygon mirror and generates the origin signal; and A condensing optical system that condenses the reflected light beam of the detection beam into a light spot on the photodetector, and makes the scanning speed of the light spot traversing the photodetector by the rotation of the rotating polygon mirror , Faster than the scanning speed of the drawing beam on the substrate. For example, the pattern drawing device of item 20 of the scope of patent application is set to follow the rotation of the rotating polygon mirror, before the drawing light beam enters the scanning optical system, the detection light beam enters the scanning optical system, and is set The photoelectric conversion element on the supporting member receives the light collected by the scanning optical system The spot of the detection beam. For example, the pattern drawing device of item 21 of the scope of patent application, wherein the scanning optical system condenses the drawing light beam on the substrate into a point light, and the drawing light beam is driven by the point light using the rotating polygon mirror In the scanning direction, the spot light is supplied by a light source device with pulsed oscillation in a period where the spot light partially overlaps. A method for inspecting the accuracy of a pattern drawing device, which checks the accuracy of the pattern drawing device. The pattern drawing device projects a drawing beam on each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, so that the plurality of The drawing light beam reflected by each of the reflective surfaces passes through the scanning optical system and condenses into spot light on the substrate supported by the supporting member, and scans in the main scanning direction. The method includes the following stages: setting stage, response Generated when each of the plurality of reflecting surfaces of the rotating polygon mirror becomes a predetermined predetermined angle, in the origin signal generated from the origin detection unit, the specific reflecting surface of the rotating polygon mirror becomes the predetermined angle The specific origin signal is drawn by scanning the main scanning direction of the spot light by using the specific reflecting surface to draw the inspection pattern; the drawing stage is repeatedly generated by the rotation of the rotating polygon mirror During the interval time of the specific origin signal, while the substrate is moved in the sub-scanning direction crossing the main scanning direction by a distance smaller than the size of the spot light, the inspection pattern is drawn on the same side; the stage is repeated to make The specific reflecting surface of the rotating polygon mirror is different, the setting stage and the drawing stage are repeated; and the inspection stage is to measure the deviation of the shape of the inspection pattern drawn on the substrate or the configuration of the main scanning direction to inspect The accuracy of the origin signal.

Images