TW201832860A - Beam scanning device, pattern drawing device, and method for examining accuracy of pattern drawing device - Google Patents

Abstract

An exposure device (EX) projects, on each of a plurality of reflective surfaces (RP) of a polygon mirror (PM) that rotates around a rotational axis (AXp), a processing beam (LBn), and scans, on a substrate (P) via an f[Theta] lens system (FT), the processing beam (LBn) reflected by each of the plurality of reflective surfaces (RP). The exposure device (EX) is provided with: a starting point sensor which generates a starting point signal (SZn) each time any of the plurality of reflective surfaces (RP) of the polygon mirror (PM) reaches a prescribed angle; and a correction unit which generates corrected starting point signals (SZn') which have been corrected using correction values corresponding to the variation amounts in the time intervals between the generated starting point signals (SZn) corresponding to each of the plurality of reflective surfaces (RP).

Description

 Beam scanning device, pattern drawing device, and pattern inspection device precision inspection method  

The present invention relates to a beam scanning device that scans a spot light of a light beam that is irradiated onto an illuminated surface of an object, a pattern drawing device that draws a predetermined pattern by using the light beam scanning device, and an accuracy check of the pattern drawing device method.

In the related art, it is known to use, for example, a laser processing apparatus (light scanning device) of the Japanese Patent Publication No. 2005-262260, as shown below, to perform the operation of projecting a point light of a laser beam onto an object to be irradiated (processing The object is irradiated by the scanning mirror (polygon mirror) in the one-dimensional direction, and the object to be irradiated is moved in the sub-scanning direction orthogonal to the main scanning direction, and is irradiated. A desired pattern or image (text, graphic, etc.) is formed on the body.

It is disclosed in Japanese Laid-Open Patent Publication No. 2005-262260 that a galvanometer mirror is provided which reflects laser light from the oscillator 1 and irradiates the laser beam onto the workpiece at an irradiation position on the workpiece. Correction in the Y direction (sub-scanning direction); a polygon mirror that reflects the laser light reflected by the galvanometer mirror and scans it in the X direction (main scanning direction) on the workpiece; the fθ lens makes The laser light reflected by the galvanometer mirror is condensed on the workpiece; and the control unit responds to the distortion aberration generated when the laser light passes through the fθ lens to correct the irradiation position of the laser light in the Y direction on the workpiece The error mode controls the reflection angle of the galvanometer mirror, and controls the pulse oscillation interval of the laser light generated by the oscillator in such a manner as to correct the illumination position error of the X-direction of the laser light on the workpiece. Further, in Fig. 8 of Japanese Laid-Open Patent Publication No. 2005-262260, a laser light source and a detector are provided, and the oscillator is controlled as shown in Fig. 9 of Japanese Laid-Open Patent Publication No. 2005-262260, based on the end detection signal. a configuration of a timing of the pulse oscillation, the laser source emitting the detected laser light for detecting the end of each of the reflecting surfaces of the polygon mirror in the rotation of the polygon mirror, the detector receiving the reflection at the end of each of the reflecting surfaces of the polygon mirror It detects the reflected light of the laser light and generates an end detection signal. In the laser processing apparatus (beam scanning device) using a polygon mirror like the one disclosed in Japanese Laid-Open Patent Publication No. 2005-262260, the higher the rotation speed of the polygon mirror, the shorter the processing time of the workpiece can be shortened. Improve productivity. However, there is a case where the rotation of the polygon mirror is higher, and the deviation of the processing position in the main scanning direction is more remarkable.

A first aspect of the present invention is a beam scanning device that projects a processing beam for each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates about a rotation axis to reflect each of the plurality of reflecting surfaces The processing light beam is scanned by the scanning optical system on the object to be irradiated, and includes an origin detecting unit that generates an origin when each of the plurality of reflecting surfaces of the rotating polygon mirror has a predetermined predetermined angle a signal; and a correction unit that generates a corrected origin signal corrected by the correction value, the correction value corresponding to the correction of the amount of deviation of the time interval of the origin signal generated according to each of the plurality of reflecting surfaces value.

A second aspect of the present invention is a pattern drawing device that projects a light beam for drawing by a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis to reflect each of the plurality of reflecting surfaces The drawing light beam is scanned by the scanning optical system on the object to be irradiated, and the image is drawn on the object to be irradiated, and includes an origin detecting unit for each of the plurality of reflecting surfaces of the rotating polygon mirror The originating signal is generated when each of the predetermined angles is set; the drawing control unit sets the starting time point of the pattern drawing by the drawing light beam from a predetermined delay time from the generation of the origin signal; and the correction The portion corrects the delay time set by the drawing control unit for each of the plurality of reflecting surfaces based on a correction value corresponding to a deviation of a time interval between the plurality of reflecting surfaces at the predetermined angle.

A third aspect of the present invention is a pattern drawing device that projects a light beam for drawing by a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis to reflect each of the plurality of reflecting surfaces The drawing light beam is scanned by the scanning optical system on the substrate supported by the supporting member, and the pattern is drawn on the substrate, and the origin detecting unit is provided for each of the plurality of reflecting surfaces of the rotating polygon mirror. The originating signal is generated when each of the predetermined angles is set; and the drawing control unit sets the starting time point of the pattern drawing by the drawing light beam after the predetermined delay time from the generation of the origin signal; a portion correcting the delay time set by the drawing control unit for each of the plurality of reflecting surfaces based on a correction value corresponding to a deviation of a time interval between the plurality of reflecting surfaces at the predetermined angle; and a measuring unit that generates a reflected light generated from the reference pattern when the reference pattern formed on the support member or the substrate is scanned by the drawing beam The time between the time point and the time point at which the origin signal is generated, and the correction value corresponding to the deviation is obtained.

A fourth aspect of the present invention is a pattern drawing device that projects a light beam for drawing by a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis to reflect each of the plurality of reflecting surfaces The drawing light beam is scanned by the scanning optical system on the substrate supported by the supporting member, and the pattern is drawn on the substrate, and the origin detecting unit is provided for each of the plurality of reflecting surfaces of the rotating polygon mirror. The originating signal is generated when each of the predetermined angles is set; and the drawing control unit sets the starting time point of the pattern drawing by the drawing light beam after the predetermined delay time from the generation of the origin signal; a portion correcting the delay time set by the drawing control unit for each of the plurality of reflecting surfaces based on a correction value corresponding to a deviation of a time interval between the plurality of reflecting surfaces at the predetermined angle; and a measuring portion having a photoelectric conversion element disposed at a portion of a support surface of the support member, and when the photoelectric conversion element is scanned by the drawing beam The time between the time point of generation of the obtained photoelectric signal and the time point of generation of the origin signal is obtained, and a correction value corresponding to the deviation is obtained.

A fifth aspect of the present invention is a method for inspecting the accuracy of a pattern drawing device for projecting a light beam for drawing on each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates about a rotation axis to cause the plurality of light beams to be The drawing light beam reflected by each of the reflecting surfaces is condensed into a spot light on the substrate supported by the supporting member through the scanning optical system, and is scanned in the main scanning direction, and the method includes the following stages: setting phase, response When the specific reflection surface of the rotating polygon mirror in the origin signal generated from the origin detecting portion becomes the predetermined angle when each of the plurality of reflecting surfaces of the rotating polygon mirror becomes a predetermined predetermined angle The specific origin signal is drawn by the scanning of the main scanning direction of the spot light by the specific reflecting surface; the drawing phase is repeatedly generated by the rotation of the rotating polygon mirror Between the intervals of the specific origin signals, the substrate is made to have a distance smaller than the spot light in a sub-scanning direction crossing the main scanning direction. Moving, drawing the inspection pattern; repeating the step of making the specific reflection surface of the rotating polygon mirror different, repeating the setting phase and the drawing phase; and checking the shape of the inspection pattern drawn on the substrate Or the deviation of the configuration of the main scanning direction, and check the accuracy of the origin signal.

50J‧‧‧ openings

60a‧‧‧beam light transmission unit (beam light transmission system)

60b‧‧‧beam light receiving unit (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 department

241‧‧‧Multiplication

242‧‧‧ Wave memory unit (memory unit)

244‧‧‧ Address Generation Department

246‧‧‧ Waveform Analysis Department

Aw‧‧ arrow

AX1, AXb, AXf‧‧‧ optical axis

AXo‧‧‧ central axis

AXp‧‧‧Rotary axis

Axv‧‧‧ inspection area

Bga‧‧‧Laser beam (beam)

Bgb, Bgb'‧‧· reflected beam

Bgc, Bgd, LB, LB1~LB6, LBn‧‧‧ beams

BS1‧‧‧Polarizing beam splitter

CCK, CLK‧‧‧ clock signal

CLK2‧‧‧ sampling clock signal

CTu‧‧‧ average position

CYa‧‧1st cylindrical lens

CYb‧‧‧2nd cylindrical lens

DF1~DF6, DFn‧‧‧ drive signals

DR‧‧‧Rotary tube

DTc‧‧‧Photodetector

DTo‧‧‧ photoelectric conversion components

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‧‧‧ concentrating lens

Gb, Gc‧‧ collimating lens

GLa, GLb‧‧ lens system

GSa, GSb‧‧‧Gap Sensor (Line Sensitive Detector)

IC1, IC2‧‧‧ Current Amplifier

IC3‧‧‧ Comparator

IMn, IM1~IM6‧‧‧ incident mirror

LBnz‧‧0 light beam

Lcc‧‧‧ Straight line

LDo‧‧‧Semiconductor laser source

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

M1~M12, M20~M24, M20a, MRa‧‧‧ mirror

Mcc‧‧‧ Rotating fiducial mark

MPa~MPh‧‧‧

OS1~OS6, OSn‧‧‧Selection optics

P‧‧‧Substrate (irradiated body)

PD1, PD2‧‧‧ light surface

PM‧‧‧Multiface mirror

Ps‧‧‧ face

PTL1, PTL2, PTL3‧‧‧ reference pattern

RM‧‧‧Rotary motor

RP, RPa~RPh, RPa'‧‧·reflecting surface

RPa/b~RPh/a‧‧‧ position between reflective surfaces

RST‧‧‧Reset signal

SDn‧‧‧ depicting information

Sff‧‧‧Shift signal

SJ‧‧‧Control Information

Sj‧‧‧Rotary pulse signal

SL1~SL6, SLn‧‧‧ depicting lines

SP, SPr‧‧‧ spot light

STa, STb‧‧‧ output signals

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

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

TDa~TDh‧‧‧ Turning time

Tog, Tog', Tog1, Tog2‧‧‧ origin moment

Tpt‧‧‧ test pattern

TR‧‧‧ absorber

Tsr'‧‧‧ benchmark time

Tu1, Tu2‧‧‧ moments

U1~U6, Un‧‧‧ drawing unit

Vref‧‧‧ offset voltage (reference voltage)

X, Y, Z‧‧ Direction

△Te‧‧‧ deviation

△Tm1~△Tm7, △Tma~△Tmh‧‧‧ Origin interval

△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 according to the first embodiment.

FIG. 2 is a detailed structural diagram of the drawing unit shown in FIG. 1.

Fig. 3 is a view showing the arrangement of a polygon mirror, an fθ lens system, and a beam receiving system constituting the origin sensor in the drawing unit shown in Fig. 2 in the XY plane.

Fig. 4 is a view showing the arrangement of the beam light-emitting system and the light-receiving system shown in Figs. 2 and 3 in a simplified manner.

Fig. 5 is a view showing a detailed configuration of the photoelectric conversion element shown in Fig. 3 or Fig. 4;

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

Fig. 7 is a view showing a specific configuration of the optical element for selection and the periphery of the incident mirror.

Figure 8 is a plan view of the eight-sided polygon mirror shown in Figure 3 or Figure 4.

Fig. 9 is a view for explaining a method of measuring the reproducibility (deviation) of the generation timing of the origin signal.

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

Fig. 11 is a view showing the results obtained by measuring the reproducibility of the origin signal corresponding to each of the reflecting surfaces of the polygon mirror by the method of Fig. 9 under the predetermined conditions.

Fig. 12 is a view showing the results of the reproducibility of the origin signal generated corresponding to each of the reflecting surfaces of the polygon mirror by the method of Fig. 9 under conditions different from those of Fig. 11.

FIG. 13 is a view showing a state in which a point light having an average of two pulses per pixel is superimposed on the sub-scanning direction in the main scanning direction at a half of the spot size, and a continuous pattern of five pixels in the main scanning direction is drawn. .

Fig. 14 is a view schematically showing a graph of the characteristics of the actual measurement example of Fig. 12.

Fig. 15 is a timing chart showing the state in which the origin signal (correction origin signal) is generated by correcting the origin signal.

Fig. 16 is a view showing an example of a configuration of a correction circuit (correction unit) for inputting an origin signal from the photoelectric conversion element and generating a corrected origin signal (correction origin signal) as shown in Fig. 15.

Fig. 17 is a view showing the configuration of an origin sensor according to a second modification.

Fig. 18 is a view showing an example of a waveform of a photoelectric signal generated from a photodetector when a line formed on the outer peripheral surface of the rotating cylinder and a gap-shaped reference pattern are scanned by spot light.

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

Fig. 20 is a timing chart showing an example of variations in the timing of generation of the origin time of the correction origin signal or the origin signal using the circuit configuration of Fig. 19.

Fig. 21 is a view for explaining a method of test exposure for verifying the accuracy of the correction of the origin signal (or the origin signal before correction) of the third embodiment.

Fig. 22 is a view in which a line-shaped reference pattern continuous in the circumferential direction is provided at an end portion in the direction in which the central axis of the outer peripheral surface of the rotary cylinder extends.

Fig. 23 is a partial cross-sectional view showing the rotary cylinder DR of the fourth embodiment.

A preferred embodiment of the beam scanning device, the pattern drawing device, and the pattern drawing device according to the present invention will be described in detail below with reference to the accompanying drawings. Furthermore, the aspect of the present invention is not limited to the embodiments, and includes various modifications and improvements. In other words, the constituent elements described below can be easily assumed by the operator and substantially the same, and the constituent elements described below can be combined as appropriate. Further, various omissions, substitutions, and changes of the components may be made without departing from the scope of the invention.

[First Embodiment]

1 is a perspective view showing a schematic configuration of an exposure apparatus (pattern drawing apparatus) EX that performs exposure processing on a substrate (object to be irradiated) P of the first embodiment. In the following description, unless otherwise specified, an XYZ orthogonal coordinate system in which the direction of gravity is the Z direction is set, and the X direction, the Y direction, and the Z direction are described in accordance with the arrows shown in the drawing.

The exposure apparatus EX is a substrate processing apparatus used in a component manufacturing system for manufacturing an electronic component by performing predetermined processing (exposure processing or the like) on the substrate P. The component manufacturing system is, for example, a manufacturing system in which a production line such as a flexible display for an electronic component, a film-shaped touch panel, a film-shaped color filter for a liquid crystal display panel, a flexible wiring, or a soft sensor is manufactured. Hereinafter, description will be made on the assumption that the electronic component is a flexible display. 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 type production method, that is, a supply roller (not shown) in which a flexible (flexible) sheet-shaped substrate (sheet substrate) P is wound into a roll shape. After the substrate P is sent out and various processes are continuously performed on the substrate P to be fed, the substrate P after various processes is taken up by a recovery roller (not shown). Therefore, the substrate P after the various processes is a substrate for a plurality of chamfers in which a plurality of elements (display panels) are arranged in a state in which the substrates P are connected in the transport direction. The substrate P conveyed from the supply roller is sequentially subjected to various processes by the process device of the previous step, the exposure device EX, and the process device of the subsequent step, and is taken up by the recovery roller. The substrate P has a strip shape in which the moving direction (transport direction) of the substrate P is in the longitudinal direction (long direction) and the width direction is in the short side direction (stripe direction).

For the substrate P, for example, a resin film or a foil made of a metal or an alloy such as stainless steel is used. As a material of the resin film, for example, a polyethylene resin, a polypropylene resin, a polyester resin, an ethylene-vinyl ester copolymer resin, a polyvinyl chloride resin, a cellulose resin, a polyamide resin, or a polyimide resin may be used. At least one of a polycarbonate resin, a polystyrene resin, and a vinyl acetate resin. Further, the thickness or rigidity (Young's modulus) of the substrate P is such that the substrate P does not have a crease due to buckling or irreversible wrinkles as long as it passes through the transport path of the component manufacturing system or the exposure device EX. can. As a base material of the substrate P, a film such as PET (polyethylene terephthalate) or PEN (polyethylene naphthalate) having a thickness of about 25 μm to 200 μm is preferably a representative of a sheet substrate.

Since the substrate P is heated in each process performed in the component manufacturing system, it is preferable to select the substrate P of a material having a thermal expansion coefficient which is not too large. For example, the coefficient of thermal expansion can be suppressed by mixing an inorganic filler with a resin film. The inorganic filler may also be, for example, titanium oxide, zinc oxide, aluminum oxide, or cerium oxide. In addition, the substrate P may be a single layer body of an extremely thin glass having a thickness of about 100 μm, which is produced by a float method or the like, or a laminate obtained by laminating the above-mentioned resin film, foil, or the like in the ultra-thin glass.

In addition, the flexibility of the substrate P means a property that the substrate P can be bent without being sheared or broken even if a force of its own weight is applied to the substrate P. Moreover, the nature of buckling due to the degree of self-weight is also included in flexibility. Further, the degree of flexibility varies depending on the material, size, thickness of the substrate P, the layer structure formed on the substrate P, the temperature, or the environment such as humidity. In other words, when the substrate P is accurately wound around the conveying direction of the various conveying rollers and the rotating cylinder provided in the conveying path of the component manufacturing system (exposure device EX), the substrate P can be unbuckled. The substrate P can be smoothly transported by creases or breakage (breaking or cracking), which is called the range of flexibility.

The processing device of the previous step (including a single processing unit or a plurality of processing units) transports the substrate P fed from the supply roller toward the exposure device EX at a predetermined speed in the longitudinal direction, and transports the substrate P to the exposure device EX at a predetermined speed. The substrate P is subjected to the processing of the previous step. By the process of the previous step, the substrate P transferred to the exposure apparatus EX is a substrate (photosensitive substrate) on which a photosensitive functional layer (photosensitive layer) is formed.

The photosensitive functional layer is applied to the substrate P as a solution and dried to form a layer (film). The photosensitive functional layer is represented by a photoresist (liquid or dry film), but as a material that does not require development treatment, a photosensitive decane couple whose lyophilic/liquid-repellent property is irradiated by ultraviolet rays is modified. A mixture (SAM) or a photosensitive reducing agent that exposes a reduction group is exposed to a portion irradiated with ultraviolet rays. In the case where a photosensitive decane coupling agent is used as the photosensitive functional layer, the ultraviolet-exposed pattern portion on the substrate P is modified from liquid-repellent property to lyophilic property. Therefore, it is possible to form a thin film transistor (TFT) by selectively applying a liquid containing a conductive ink (an ink containing conductive nano particles such as silver or copper) or a semiconductor material to the lyophilic portion. A pattern layer of wiring for electrodes, semiconductors, insulation or connections. In the case where a photosensitive reducing agent is used as the photosensitive functional layer, the ultraviolet-exposed pattern portion on the substrate P exposes the plated reducing group. Therefore, after the exposure, the substrate P is immersed in a plating solution containing palladium ions or the like for a fixed period of time to form (precipitate) a pattern layer of palladium. Such a plating treatment is an additive process, but it can also be premised on the etching process of a subtractive process. In this case, the substrate P to be sent to the exposure apparatus EX is preferably a metal film in which the base material is made of PET or PEN, and aluminum (Al) or copper (Cu) is vapor-deposited on the surface thereof. And further, a photoresist layer is laminated thereon.

The exposure apparatus (processing apparatus) EX transports the substrate P transferred from the processing apparatus of the previous step to the processing apparatus (including a single processing unit or a plurality of processing units) in a subsequent step at a predetermined speed, and faces the substrate P. Processing device for exposure processing. The exposure apparatus 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 a pattern for an electronic component (for example, a pattern of an electrode or a wiring of a TFT constituting an electronic component). Thereby, a latent image (modified portion) corresponding to the above pattern is formed on the photosensitive functional layer.

In the present embodiment, the exposure apparatus EX is an exposure apparatus (such as a so-called spot scanning type exposure apparatus) which does not use a direct mask type of photomask as shown in FIG. The exposure apparatus EX includes a rotating cylinder DR that supports the substrate P to perform sub-scanning and transports in the longitudinal direction, and a plurality of (here, six) drawing units Un (U1 to U6). Each portion of the substrate P supported by the cylindrical shape of the rotating cylinder DR is subjected to pattern exposure; and each of the plurality of drawing units Un (U1 to U6) is subjected to a pulsed light beam LB (pulse beam) for exposure. The spot light SP is scanned one-dimensionally (main scanning) by a polygon mirror (scanning member) on the irradiated surface (photosensitive surface) of the substrate P in a predetermined scanning direction (Y direction), and is based on 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 such as an electronic component, a circuit, or a wiring is drawn on the illuminated surface of the substrate P. In other words, the sub-scan of the substrate P and the main scanning of the spot light SP cause the spot light SP to be two-dimensionally scanned on the illuminated surface (the surface of the photosensitive functional layer) of the substrate P, and the irradiated surface of the substrate P is irradiated. Depicting an established pattern of exposure. Further, since the substrate P is conveyed in the longitudinal direction, the exposed regions of the exposure pattern by the exposure device EX are provided at a predetermined interval along the longitudinal direction of the substrate P. Since the electronic component is formed in the exposed region, the exposed region is also the component forming region.

As shown in FIG. 1, the rotating cylinder DR has a central axis AXo extending in the Y direction and extending in a direction intersecting the direction in which gravity acts, and a cylindrical outer circumferential surface having a fixed radius from the central axis AXo. The rotating cylinder DR supports (holds) one of the substrates P in a cylindrical shape along the outer peripheral surface (circumferential surface) while rotating around the central axis AXo to lengthen the substrate P. Transport in the direction of the article. The rotating cylinder DR is supported by a region (portion) 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 cylinder DR supports (closely holds) the substrate P from the side (back surface) side opposite to the surface on which the electronic component is formed (the side on which the photosensitive surface is formed). Further, on both sides of the rotating cylinder DR in the Y direction, a shaft (not shown) supported by the bearing to rotate the rotating cylinder DR around the central axis AXo is provided. The rotation torque from a rotary drive source (for example, a motor or a speed reduction mechanism) (not shown) is applied to the shaft, and the rotary drum DR is rotated at a fixed rotational speed around the central axis AXo.

The light source device (pulse light source device) LS generates and emits a pulsed light beam (pulse beam, pulsed light, laser) LB. The light beam LB is ultraviolet light having a sensitivity to the photosensitive layer of the substrate P and having a peak wavelength in a wavelength band of 370 nm or less. The light source device LS emits a pulsed light beam LB at a frequency (oscillation frequency, predetermined frequency) Fa according to control of a drawing control device not shown. The light source device LS is a fiber-optic amplifying laser light source, which is a semiconductor laser element that generates pulsed light in an infrared wavelength region, an optical fiber amplifier, and a pulse that converts pulsed light in an amplified infrared wavelength region into an ultraviolet wavelength region. A light wavelength conversion element (harmonic generating element) or the like is formed. By configuring the light source device LS as described above, it is possible to obtain pulsed light of ultraviolet light having an oscillation frequency Fa of several hundred MHz and a light-emitting time of one pulse of light of several tens of microseconds or less. Further, the light beam LB emitted from the light source device LS is a thin parallel light beam having a beam diameter of about 1 mm or less. The light source device LS is used 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 data ("0" or "1" in terms of a logical value). , disclosed in International Gazette No. 2015/166910.

The light beam LB emitted from the light source device LS is selectively (optionally) supplied to each of the drawing units Un (U1 to U6) through the beam switching portion, and the beam switching portion is selected as a plurality of switching elements. The optical element OSn (OS1 to OS6), the plurality of mirrors M1 to M12, the plurality of incident mirrors IMn (IM1 to IM6), and the absorber TR are configured. The selection optical element OSn (OS1 to OS6) is transparent to the light beam LB, and is composed of an acoustic light modulation element (AOM: Acousto-Optic Modulator) which is driven by an ultrasonic signal to make incidence. The diffracted light of the light beam LB is deflected at a predetermined angle. A plurality of selection optical elements OSn and a plurality of incident mirrors IMn are provided corresponding to each of the plurality of drawing units Un. For example, the selection optical element OS1 and the entrance mirror IM1 are provided corresponding to the drawing unit U1, and similarly, the selection optical elements OS2 to OS6 and the entrance mirrors 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 the optical path in a meander shape by the mirrors M1 to M12. Hereinafter, the case where the selection optical element OSn (OS1 to OS6) is in an off state (a state in which no ultrasonic signal is applied but no diffracted light is generated once) is described in detail. Although not shown in FIG. 1, a plurality of lenses are disposed in the beam path from the mirror M1 to the absorber TR, and the plurality of lenses converge the beam LB from the parallel beam or converge after convergence. The beam LB is restored to a parallel beam. This configuration will be described below using FIG.

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

When each of the optical elements OSn for selection is applied with an ultrasonic signal (high-frequency signal), a one-time diffraction is performed in which the incident light beam (zero-order light) LB is diffracted at a diffraction angle corresponding to the frequency of the high frequency. The light is emitted as an outgoing beam (beam LBn). Therefore, the light beam emitted from the selective optical element OS1 as the primary diffracted light becomes LB1, and similarly, the light beams emitted from the selective optical elements OS2 to OS6 as the primary diffracted light become LB2 to LB6. In this manner, each of the selection optical elements OSn (OS1 to OS6) functions to deflect the optical path of the light beam LB from the light source device LS. However, since the actual acousto-optic modulation element has an efficiency of generating light of one pass of about 80% of the zero-order light, the light beam LBn (LB1 to LB6) which is biased by the selection of each of the optical elements OSn is larger than the original one. The intensity of the beam LB is reduced. Further, in the present embodiment, one of the selection optical elements OSn (OS1 to OS6) is controlled by a drawing control device (not shown) so that only a fixed time is turned on. When the selected one of the selection optical elements OSn is in the ON state, the zero-order light that has not been linearly circulated by the selection optical element OSn remains about 20%, but is eventually absorbed by the absorber TR.

Each of the selection optical elements OSn is provided such that the light beam LBn (LB1 to LB6) which is the first-order diffracted light is deflected in the -Z direction with respect to the incident light beam LB. The light beam LBn (LB1 to LB6) which is deflected and emitted by the selection of each of the optical elements OSn is projected onto the incident mirror IMn (IM1 to IM6) which is disposed at a predetermined distance from each of the selection optical elements OSn. ). Each of the incident mirrors IMn reflects the incident light beams LBn (LB1 to LB6) in the -Z direction, and guides the light beams LBn (LB1 to LB6) to the respective drawing units Un (U1 to U6).

The same configuration, function, operation, and the like of each of the selection optical elements OSn may be used. Each of the plurality of selection optical elements OSn turns on/off the diffracted light diffracted by the incident light beam LB in accordance with the on/off of the drive signal (ultrasonic signal) from the drawing control device. For example, when the selection optical element OS5 is turned off without applying a driving signal (high-frequency signal) from the drawing control device, the incident light beam LB from the light source device LS is transmitted without being diffracted. Therefore, the light beam LB passing through the selection optical element OS5 is incident on the mirror M3. On the other hand, when the selection optical element OS5 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 by the selection optical element OS5 is controlled in accordance with the on/off of the drive signal. In this manner, by the switching operation of each of the selection optical elements OSn, the light beam LB from the light source device LS can be guided to any one of the drawing units Un, and the drawing unit Un to which the light beam LBn is incident can be switched. In this way, a configuration in which a plurality of selection optical elements OSn are arranged in series (series) 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 is disclosed in International Publication No. 2015/ No. 166910.

For example, each of the selection optical elements OSn (OS1 to OS6) constituting the light beam switching unit is turned on in a fixed time, for example, OS1 → OS2 → OS3 → OS4 → OS5 → OS6 → OS1 → .... This order is determined based on the order in which the scanning start timing of the spot light is set for each of the drawing units Un (U1 to U6). In other words, in the present 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, thereby drawing any one of the units U1 to U6. One of the reflecting surfaces of the polygon mirror can be switched in a time division manner on the substrate P by one spot scanning method. Therefore, the order of the spot scanning of the drawing unit Un can be arbitrary as long as the phase of the rotation angle of the polygon mirror of each of the drawing units Un is synchronized in a predetermined relationship. In the configuration of FIG. 1, the three drawing units U1, U3, and U5 are arranged side by side in the Y direction on the upstream side in the transport direction of the substrate P (the direction in which the outer peripheral surface of the rotary cylinder DR moves in the circumferential direction). On the downstream side of the transport 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 to the substrate P starts from the odd-numbered drawing units U1, U3, and U5 on the upstream side, and after the substrate P is transported by the fixed length, the even-numbered drawing units U2, U4, and U6 on the downstream side. Since the pattern drawing is also started, the order of the spot scanning of the drawing unit Un can be set to U1 → U3 → U5 → U2 → U4 → U6 → U1 → .... Therefore, each of the selection optical elements OSn (OS1 to OS6) is determined to be OS1→OS3→OS5→OS2→OS4→OS6→OS1→... in the order in which the fixed time is turned on. Further, even when the selection optical element OSn corresponding to the drawing unit Un having no pattern to be drawn is in the ON state, the switching of the selection optical element OSn can be switched on/off according to the drawing data. Since the control can be forcibly maintained in the off state, the 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 performing main scanning of the incident light beams LB1 to LB6. In the present embodiment, each of the polygon mirrors PM of each drawing unit Un is synchronously controlled so as to maintain a fixed rotational angle phase while rotating at the same rotational speed. Thereby, the timing of the main scanning (the main scanning period of the spot light SP) of each of the light beams LB1 to LB6 projected from the drawing units U1 to U6 to each of the light beams LB1 to LB6 can be set so as not to overlap each other. Therefore, by switching the on/off switching of each of the selection optical elements OSn (OS1 to OS6) provided in the beam switching unit in synchronization with the rotation angle position of each of the six polygon mirrors PM, it is possible to realize the switching between the ON/OFF of each of the selection optical elements OSn (OS1 to OS6) provided in the beam switching unit. The light beam LB from the light source device LS is time-distributed to the efficient exposure processing of each of the plurality of drawing units Un.

The synchronization control of the phase alignment of the rotation angle of each of the six polygon mirrors PM and the switching timing of the ON/OFF of each of the selection optical elements OSn (OS1 to OS6) is disclosed in International Publication No. 2015 In the case of the No. 166910, in the case of the 8-sided polygon mirror PM, regarding the scanning efficiency, about 1/3 of the rotation angle (45 degrees) corresponding to one reflecting surface corresponds to the spot light on the drawing line SLn. Since the SP scans once, the switching of the on/off of each of the selection optical elements OSn (OS1 to OS6) is controlled in such a manner that the six polygon mirrors PM relatively reverse the phase of the rotation angle. The rotation is performed by 15 degrees, and the eight reflection surfaces of the polygon mirrors PM are skipped on one side to scan the light beam LBn. As described above, the drawing method in which the reflecting surface of the polygon mirror PM is skipped and used is also disclosed in International Publication No. 2015/166910.

As shown in Fig. 1, the exposure apparatus EX is a so-called multi-head type direct exposure method in which a plurality of drawing units Un (U1 to U6) having the same configuration are arranged. Each of the drawing units Un draws a pattern on each of the partial regions divided in the Y direction by the substrate P supported by the outer circumferential surface (circumferential surface) of the rotating cylinder DR. Each of the drawing units Un (U1 to U6) projects the light beam LBn from the beam switching unit onto the substrate P (the irradiated 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 onto the substrate P becomes the spot light SP. Further, the spot light SP of the light beam LBn (LB1 to LB6) projected onto the substrate P is scanned in the main scanning direction (Y direction) by the rotation of the polygon mirror PM of each drawing unit Un. By scanning the spot light SP, a linear drawing line (scanning line) SLn (hereinafter, 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, and similarly, the drawing units U2 to U6 scan the spot light SP along the drawing lines SL2 to SL6. As shown in FIG. 1, the drawing lines SLn (SL1 to SL6) of the plurality of drawing units Un (U1 to U6) are centered on the center axis AXo of the rotating cylinder DR and parallel to the YZ plane, and are in the rotating cylinder DR. Arranged in two rows in a circumferential direction in a misaligned arrangement. The odd-numbered drawing lines SL1, SL3, and SL5 are located on the illuminated surface of the substrate P on the upstream side (the -X direction side) of the substrate P in the transport direction with respect to the center plane, and are arranged at predetermined intervals along the Y direction. In 1 line. The even-numbered drawing lines SL2, SL4, and SL6 are located on the illuminated surface of the substrate P on the downstream side (+X-direction side) of the substrate P in the transport direction with respect to the center plane, and are arranged at predetermined intervals along the Y direction. In 1 line. Therefore, the plurality of drawing units Un (U1 to U6) are also arranged in two rows of misalignment in the transport direction of the substrate P via the center plane, and the odd-numbered drawing units U1, U3, and U5 are observed when viewed in the XZ plane. The even number of drawing units U2, U4, U6 are arranged symmetrically with respect to the center plane.

The odd-numbered drawing lines SL1, SL3, and SL5 and the even-numbered drawing lines SL2, SL4, and SL6 are spaced apart from each other in the X direction (the transfer direction of the substrate P), but in the Y direction (the width direction of the substrate P, the main The scanning directions are not joined to each other separately. 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 cylinder DR. Further, joining the drawing line SLn in the Y direction means a relationship in which the positions of the end portions of the drawing lines SLn in the Y direction are adjacent or partially repeated. When the end portions of the drawing lines SLn are overlapped with each other, for example, it is preferable to repeat in the range of several % or less in the Y direction including the drawing start point or the drawing end point with respect to the length of each drawing line SLn.

In this manner, the plurality of drawing units Un (U1 to U6) share the scanning area in the Y direction (the division of the main scanning range) so as to cover the size of the exposure region on the substrate P in the width direction. For example, when the main scanning range (the length of the drawing line SLn) in the Y direction of one drawing unit Un is set to about 30 to 60 mm, a total of six drawing units U1 to U6 are arranged in the Y direction, and the drawing can be performed. The width of the exposed area in the Y direction is widened to about 180 to 360 mm. Furthermore, the length of each drawing line SLn (SL1 to SL6) (the length of the drawing range) is basically the same. In other words, the scanning distance of the spot light SP of the light beam LBn scanned along each of the drawing lines SL1 to SL6 is basically the same.

In the case of the present embodiment, when the light beam LB from the light source device LS is pulse light having a light emission time of several tens of microseconds or less, the spot light SP projected onto the drawing line SLn during the main scanning period is oscillated according to 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 of the light beam LB and the spot light SP projected by the next one pulse light in the main scanning direction. The amount of the overlap is set in accordance with 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 dimension of the intensity of the peak intensity of the spot light SP of 1/e ² (or 1/2). . In the present embodiment, the scanning speed Vs of the spot light SP (the rotational speed of the polygon mirror PM) and the oscillation frequency Fa are set such that the spot light SP overlaps the effective size (size) Φ by about Φ × 1/2. . Therefore, the projection interval of the pulsed spot light SP along the main scanning direction becomes Φ/2. Therefore, it is preferable that the substrate P also moves the spot light SP between the one scan and the next scan of the spot light SP along the drawing line SLn in the sub-scanning direction (the direction orthogonal to the drawing line SLn). The effective size Φ is set to a distance of approximately 1/2. Further, it is preferable that when the drawing lines SLn adjacent in the Y direction are continuous in the main scanning direction, they are also overlapped by Φ/2. In the present embodiment, the size (size) Φ of the spot light SP is set to about 3 to 4 μm.

Each drawing unit Un (U1 to U6) is set so that each light beam LBn travels toward the central axis AXo of the rotating cylinder DR when viewed in the XZ plane. Thereby, the optical path (beam main ray) of the light beam LBn which travels from the drawing unit Un (U1 to U6) toward the substrate P is parallel to the normal line of the irradiated surface of the substrate P on the XZ plane. Moreover, the light beam LBn which is irradiated to the drawing line SLn (SL1 to SL6) from each drawing unit Un (U1 to U6) is always perpendicular to the tangent plane at the drawing line SLn of the surface of the substrate P which is 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 onto the substrate P are scanned in a state of telecentricity.

Since the drawing unit (beam scanning device) Un shown in FIG. 1 has the same configuration, the drawing unit U1 will be simply described. The detailed configuration 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 (drawing lens for drawing) FT. Further, in FIG. 1, although not shown, the first cylindrical lens CYa (see FIG. 2) is disposed in front of the polygon mirror PM as viewed from the traveling direction of the light beam LB1, and the fθ lens system (f-θ) The lens unit FT is provided with a second cylindrical lens CYb (see FIG. 2). The positional change in the sub-scanning direction of the spot light SP (drawing line SL1) due to the tilt error of each reflecting surface of the polygon mirror PM is corrected by the first cylindrical lens CYa and the second cylindrical lens CYb.

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

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 makes the incident light beam LB1 one-dimensionally deflected (reflected) in a plane parallel to the XY plane. Specifically, the polygon mirror (rotary polygon mirror, movable deflecting 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 the present embodiment, reflection is performed) The number of faces RP Np is set to 8) a rotating polygon mirror. By rotating the polygon mirror PM around the rotation axis AXp in a predetermined rotation direction, the reflection angle of the pulsed light beam LB1 irradiated to the reflection surface can be continuously changed. Thereby, the light beam LB1 can be deflected by the one reflecting surface RP, and the spot light SP of the light beam LB1 irradiated onto 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 the one rotation of the polygon mirror PM, the number of the drawing lines SL1 scanned by the spot light SP on the illuminated surface of the substrate P is at most eight in the same number as the number of the reflecting surfaces RP.

The fθ lens system (scanning system lens, scanning optical system) FT system projects the light beam LB1 reflected by the polygon mirror PM to the scanning lens of the telecentric system of the mirror M24. The light beam LB1 that has passed through the fθ lens system FT passes through the mirror M24 and becomes the 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 such that the light beam LB1 in the XZ plane travels toward the central axis AXo of the rotating cylinder DR. The incident angle θ of the light beam LB1 toward the fθ lens system FT varies according to the rotation angle (θ/2) of the polygon mirror PM. The fθ lens system FT transmits the light beam LB1 through the mirror M24 to the image height position on the illuminated surface of the substrate P which is proportional to the incident angle θ. When the focal length 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 accurately and accurately scanned in the Y direction by the fθ lens system FT. Further, the light beam LB1 incident on the fθ lens system FT is one-dimensionally deflected by the polygon mirror PM (parallel to the XY plane) to be the 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 mirror M21, the mirror M22, the first cylindrical lens CYa, the mirror M23, the polygon mirror PM, the fθ lens system FT, the mirror M24, and the second cylindrical lens CYb. Further, in the drawing unit Un, in order to detect the timing at which the drawing unit Un can start drawing (the scanning start timing of the spot light SP), the origin detection sensing as the angular position of each of the reflecting surfaces of the detecting polygon mirror PM is provided. The beam transmitting system 60a and the beam receiving system 60b of the device (origin detector). Further, a photodetector DTc for detecting the illuminated surface of the substrate P (or the rotating cylinder) is transmitted through the fθ lens system FT, the polygon mirror PM, and the polarization beam splitter BS1, etc., in the drawing unit Un. The surface of the DR) reflected light of the reflected 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 which is inclined by 45° with respect to the XY plane. The light beam LBn reflected by the mirror M20 is directed toward the mirror M20a which is away from the mirror M20 in the -X direction and travels in the -X direction. The mirror M20a is disposed 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 disposed at an angle of 45° with respect to the YZ plane, and reflects the P-polarized light beam, and transmits a light beam of a linearly polarized light (S-polarized light) that is polarized in a direction orthogonal to the P-polarized light. When 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 disposed at an angle of 45° with respect to the XY plane, and reflects the incident light beam LBn toward the mirror Z22 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 disposed at an angle of 45° with respect to the XY plane, and reflects the incident light beam LBn toward the mirror M23 in the +X direction. The light beam LBn reflected by the mirror M22 is incident on the mirror M23 through a λ/4 wavelength plate and a cylindrical lens CYa (not shown). 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 +X direction side toward the fθ lens system FT having the optical axis AXf parallel to the X axis. 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 the present embodiment) formed around the rotation axis AXp extending in the Z-axis direction, and is rotated by the rotation motor RM coaxial with the rotation axis AXp. Rotate. The rotary motor RM is rotated at a fixed rotational speed (for example, about 30,000 to 40,000 rpm) by a drawing control device (not shown). As described above, the effective length (for example, 50 mm) of the drawing lines SLn (SL1 to SL6) is set to a length below the maximum scanning length (for example, 52 mm) at which the spot light SP can be scanned by the polygon mirror PM. In the initial setting (design), the center point of the drawing line SLn (the point at 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 reflection 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. In other words, the cylindrical lens CYa converges the light beam LBn on the reflection surface of the polygon mirror PM into a slit shape (long elliptical shape) extending in a direction parallel to the XY plane. By the cylindrical lens CYa in which the bus bar is parallel to the Y direction and the cylindrical lens CYb described below, even when the reflecting surface of the polygon mirror PM is inclined from the state parallel to the Z axis, the irradiation to the substrate P can be suppressed. The irradiation position of the light beam LBn (drawing line SLn) on the irradiation surface is shifted in the sub-scanning direction.

The incident angle θ of the light beam LBn toward the fθ lens system FT (the angle with respect 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, and is projected through the cylindrical lens CYb toward the substrate P. The light beam LBn projected onto the substrate P converges on the illuminated surface of the substrate P to form a minute spot having a diameter of about several μm (for example, 2 to 3 μm) by the fθ lens system FT and the cylindrical lens CYb in which the bus bar is parallel to the Y direction. SP. As described above, when viewed in the XZ plane, the light beam LBn incident on the drawing unit Un is along the self-reflecting mirror M20 to the substrate P. The curved curved light path is bent and travels in the -Z direction and is projected onto the substrate P. Each of the six drawing units U1 to U6 scans the spot light SP of the light beams LB1 to LB6 one-dimensionally in the main scanning direction (Y direction), and transports the substrate P in the longitudinal direction. Then, the illuminated surface of the substrate P is 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 to SL6) is set to 50 mm, the effective diameter Φ of the spot light SP is set to 4 μm, and the oscillation frequency Fa of the pulse light emission of the light beam LB from the light source device LS is set. At 400 MHz, when the spot light SP is pulsed and emitted in such a manner that the spot light SP is 1/2 of each overlap diameter Φ along the drawing line SLn (main scanning direction), the main scanning direction of the pulse light of the spot light SP is spaced apart from the substrate P. The upper portion is 2 μm, and the interval corresponds to a period Tf (=1/Fa) of the oscillation frequency Fa, that is, 2.5 nS (1/400 MHz). Further, in this case, the pixel size Pxy defined on the drawing data is set to 4 μm square on the substrate P, and one pixel is exposed by two 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 rotational speed VR (rpm) of the polygon mirror PM, the effective scanning length LT, the number of reflecting surfaces of the polygon mirror PM Np (= 8), and one reflecting 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 to the following relationship.

(Φ/2)/Tf=(8.α.VR.LT)/60...(1)

When the oscillation frequency Fa is 400 MHz (Tf=2.5 nS) and the diameter Φ of the spot light SP is 4 μm, the scanning speed Vsp defined by the oscillation frequency Fa is 0.8 μm/nS (= 2 μm/2.5 nS). 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 50 mm, according to the relationship of the formula (1), the polygon mirror of the 8-sided surface is used. The rotation speed VR can be set to 36,000 rpm. Further, in this case, the scanning speed Vsp = 0.8 μm / nS is 2880 Km / h when converted to the hour speed. As described above, when the scanning speed Vsp is high, it is necessary to improve the reproducibility of the generation timing of the origin signal from the origin sensor (the beam light transmitting system 60a and the beam receiving system 60b) that determines the drawing start timing of the pattern. For example, when the size of one pixel is set to 4 μm and the minimum size (minimum line width) of the pattern to be drawn is set to 8 μm (corresponding to an amount of two pixels), the pattern formed on the substrate P is overlapped and exposed. The overlap accuracy (the range of positional errors allowed) for the secondary exposure of the pattern must be set to about 1/4 to 1/5 of the minimum line width. That is, when the minimum line width is 8 μm, the allowable range of the positional error is 2 μm to 1.6 μm. This value is equal to or less than the interval between the two pulse amounts 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 one pulse amount of the spot light SP is not allowed. Therefore, the reproducibility of the generation timing of the origin signal for determining the drawing start timing (start position) of the pattern must be set to be equal to or shorter than the period Tf (2.5 nS).

The beam receiving system 60b constituting the origin detecting sensor (hereinafter also referred to simply as the origin detecting sensor) shown in FIG. 2 is a rotating position of the reflecting surface RP of the polygon mirror PM, and is about to be able to start using the reflecting surface RP. The origin signal SZn is generated when the predetermined position before the scanning of the spot light SP of the light beam LBn is drawn. Since the polygon mirror PM has eight reflection surfaces RP, the beam light receiving system 60b outputs eight times of the origin signal SZn in one rotation of the polygon mirror PM. The origin signal SZn is sent to a drawing control device (not shown), and after the predetermined delay time Tdn has elapsed after the origin signal SZn is generated, scanning of the spot light SP along the drawing line SLn is started.

3 is a view showing the arrangement of the polygon mirror PM, the fθ lens system FT, and the beam receiving system 60b constituting the origin sensor (generalized origin detector) in the drawing unit Un in the XY plane. 3, the laser beam Bga from the beam light-emitting system 60a is projected toward one of the reflection surfaces RP of the polygon mirror PM, and the spot light SP of the drawing light beam LBn scanned in the angular range θf is located. The angle state of the reflection surface RPa at the instant of drawing the start point of the line SLn is drawn. Here, the reflecting surface RP (RPa) of the polygon mirror PM is disposed so as to be located on the incident pupil plane orthogonal to the optical axis AXf of the fθ lens system FT. Strictly speaking, the chief ray of the light beam LBn incident on the fθ lens system FT becomes the angular position of the reflection surface RP (RPa) at the moment of being coaxial with the optical axis AXf, and is the main beam of the light beam LBn from the mirror M23 toward the polygon mirror PM. The reflection surface RP (RPa) is set at a position where the light intersects the optical axis AXf. Further, the distance from the main surface of the fθ lens system FT to the surface of the substrate P (the condensed point of the spot light SP) is the focal length fo.

The laser beam Bga is projected onto the reflection surface RPa as a parallel light beam in 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 is oriented in the direction of the fθ lens system FT in the state of FIG. 3, but the reflecting surface RPa becomes the angle of the reflecting surface RPa' before the fixed time with respect to the position of FIG. At the position, the reflected light beam Bgb is incident on the lens system (optical element) GLb constituting the light beam receiving system 60b, and is reflected by the mirror Mb to reach the photoelectric conversion element (photodetector) DTo. The reflected light beam Bgb (parallel light beam) is condensed into the spot light SPr on the light receiving surface of the photoelectric conversion element DTo by the lens system GLb, and the spot light SPr is accompanied by the polygon mirror PM during the incident of the reflected light beam Bgb to the lens system GLb. The rotation is performed to scan across the light-receiving surface of the photoelectric conversion element DTo, and the photoelectric conversion element (narrow-origin origin detector) DTo generates the origin signal SZn. In the present embodiment, in order to improve the reproducibility of the generation timing of the origin signal SZn, the point of the origin detecting reflected light beam Bgb is made larger than the scanning speed Vsp of the spot light SP on the substrate P of the drawing light beam LBn. The scanning speed of the light SPr on the photoelectric conversion element DTo becomes faster, so that the focal length of the lens system GLb is larger than the focal length fo of the fθ lens system FT.

4 is a view showing a simplified arrangement of the beam light-emitting system 60a and the light-receiving system 60b shown in FIGS. 2 and 3, and the beam light-emitting system 60a is provided with a semiconductor laser light source LDo which continuously emits a laser beam Bga. (hereinafter also referred to simply as beam Bga); and a collimating lens (lens system) GLa that causes the beam Bga from the source to be a parallel beam. In order to stably detect the angular change of the reflection surface RP (RPa) of the polygon mirror PM with high precision, the light beam Bga projected to the reflection surface RP (RPa) is set to the rotation direction of the reflection surface RP (RPa) (parallel to the XY plane) A parallel beam of a certain width in the main scanning direction). On the other hand, in the light beam receiving system 60b, it is preferable that the reflected light beam Bgb is condensed on the photoelectric conversion element DTo to a point SPr which is contracted to be smaller in the main scanning direction. To this end, a lens system GLb having a focal length Fgs is provided. Since the reflected light beam Bgb becomes a parallel light beam, the distance from the reflection surface RP (RPa) of the polygon mirror PM to the lens system GLb can be relatively freely set. The light receiving surface of the photoelectric conversion element DTo is disposed at a position of a focal length Fgs on the rear side of the lens system GLb. When the reflected light beam Bgb reflected by the reflecting 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 substantially at the center of the light receiving surface of the photoelectric conversion element DTo.

In other words, when the reflected light beam Bgb' which is slightly inclined with respect to the optical axis of the lens system GLb in the main scanning direction is incident, the reflected light beam Bgb' also becomes the spot light SPr and is condensed to be substantially the same as 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 need not be telecentric, and in order to further increase the speed of the spot light SPr that traverses the light receiving surface of the photoelectric conversion element DTo, the non-telecentric is preferable. As described above, by setting the focal length distance Fgs of the lens system GLb and the focal length 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 improving the reproducibility of the origin signal SZn or the degree of improvement in reproducibility will be described below.

Fig. 5 shows a detailed configuration of the photoelectric conversion element DTo. In the present embodiment, for example, the S9684 series manufactured by Hamamatsu Photonics Co., Ltd., which is sold as a photoelectric IC for laser beam synchronization detection, is used. The photo IC is a light-receiving surface PD1, PD2, current amplifying portion IC1, IC2 of two PIN photodiodes arranged in a narrow gap (without sensing) in the scanning direction of the spot light SPr as shown in FIG. And the comparator unit IC3 is packaged in one piece. When the spot light SPr traverses in the order of the light receiving surfaces PD1 and PD2, each of the current amplifying units 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 portion IC1 that amplifies the photocurrent from the light receiving surface PD1 of the first receiving spot light SPr, and the output signal STa of the current amplifying portion IC1 is applied to the light generated by the light receiving surface PD1. When the current is zero, the voltage is biased to become the reference voltage Vref. As shown in FIG. 5(B), the comparator unit IC3 compares the levels of the output signals STa and STb, and outputs the logic signal which becomes the H level when STa>STb is the H level and the L level when STa<STb is used as the origin. Signal SZn. In the present embodiment, the time point at which the origin signal SZn is changed from the H level to the L level is the origin time (origin position) Tog, and the generation timing of the origin signal SZn means the origin time Tog. . In addition, the origin position (origin time Tog) herein does not mean that the point on the substrate P through which the optical axis AXf of the fθ lens system FT passes is set as a reference point, and The main scanning direction of the spot light SP is always at the origin of the absolute position set by the fixed distance, but relatively before the predetermined distance (or before the predetermined time) with respect to the start timing of the pattern drawing along the drawing line SLn. By.

The origin time Tog is an instant at which the level of the output signal STa falls and the level of the output signal STb rises, and the levels of the output signals STa and STb coincide. The level change (waveform of rising or falling) of the output signals STa and STb can be based on the relationship between the width dimension of the light receiving surfaces PD1 and PD2 and the magnitude of the spot light SPr, the scanning speed Vh of the spot light SPr, and the light receiving surfaces PD1 and PD2. Sexuality changes, but as long as the diameter of the spot SPr is larger than the width of the non-inductive tape and smaller than the width of the light-receiving surface PD1, each of the output signals STa and STb becomes a level change as shown in FIG. 5(A). The waveform of the stable origin signal SZn can be obtained.

6 is a schematic configuration of a light beam switching unit including a selection optical element OSn for selectively distributing a light beam LB from the light source device LS to any one of the six drawing units U1 to U6 ( OS1~OS6). The symbols of the respective members of Fig. 6 are the same as those of the members shown in Fig. 1, and the mirrors M1 to M12 shown in Fig. 1 are omitted as appropriate. The light source device LS composed of the optical fiber-amplified laser light source is connected to the drawing control device 200, and exchanges various control information SJ. The light source device LS includes therein a clock circuit for generating a clock signal CLK of an oscillation frequency Fa (for example, 400 MHz) when the light beam LB is pulsed, and the drawing data SDn of each drawing unit Un sent from the drawing control device 200 ( 1 pixel is set as a 1-bit bitmap data), so that the light beam LBn responds to the clock signal CLK in a burst mode (corresponding to the number of clock pulses corresponding to a predetermined number of clock pulses and corresponding to the number of clock pulses of a given clock) The repetition of the luminescence stop is performed by pulse illuminating.

The drawing control device 200 includes a polygon mirror rotation control unit that inputs an origin signal SZn (SZ1 to SZ6) output from an origin sensor (photoelectric conversion element DTo) of each of the drawing units U1 to U6 to draw a unit The rotation speed and the rotation angle phase of the polygon mirror PM of each of U1 to U6 are in a specified state, and the rotation motor RM of the polygon mirror PM is controlled; and the beam switching control unit is based on the origin signal SZn (SZ1 to SZ6). On/off control (application/non-application) of the drive signals DF1 to DF6 of the ultrasonic signals supplied to each of the selection optical elements OSn (OS1 to OS6) is controlled. In addition, FIG. 6 shows that the selection optical element OS4 of 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 used for intensity). The modulation is directed toward the incident mirror IM4, and is supplied to the drawing unit U4 as the light beam LB4. When the optical elements OS1 to OS6 are connected in series to the optical path of the light beam LB, the transmittance or the diffraction efficiency of each of the selection optical elements OSn corresponds to the selection optical light from the light source device LS. The intensity of the light beams LB1 to LB6 (the peak intensity of the pulse light) selected in the order of the elements OSn is different. Therefore, the drawing control device 200 adjusts the driving signals DF1 to DF6 so that the relative intensity difference between 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 (the amplitude or power of the high frequency signal).

Fig. 7 is a view showing a specific configuration around the selection optical elements OSn (OS1 to OS6) and the entrance mirrors IMn (IM1 to IM6). The light beam LB emitted from the light source device LS enters the selection optical element OSn, for example, as a parallel light beam having a small diameter (first diameter) of 1 mm or less in diameter. While the drive signal DFn as the high-frequency signal (ultrasonic signal) is not input (the drive signal DFn is off), the incident light beam LB is not directly transmitted by the selection optical element OSn. The transmitted light beam LB is transmitted through the condensing lens Ga and the collimator lens Gb which are disposed on the optical path along the optical axis AXb, and is incident on the selection optical element OSn in the subsequent stage. At this time, the light beam LB passing through the condensing lens Ga and the collimator lens Gb after the selection of the optical element OSn is coaxial with the optical axis AXb. The condensing lens Ga condenses the light beam LB (parallel light beam) passing through the selection optical element OSn so that the position of the surface Ps between the condensing lens Ga and the collimator lens Gb becomes the beam waist. The collimator lens Gb forms the light beam LB diverging from the position of the surface Ps into a parallel beam. The diameter of the light beam LB formed as a parallel beam by the collimator lens Gb becomes the first diameter. The rear focus position of the condensing lens Ga and the front focus position of the collimator lens Gb coincide with the plane Ps within a predetermined allowable range, and the front focus position of the condensing lens Ga is at a diffraction point with the selection optical element OSn. Configured in a consistent manner within the established tolerances.

On the other hand, while the driving signal DFn as the high-frequency signal is applied to the selection optical element OSn, the light beam LBn (primary diffracted light) after the incident light beam LB is diffracted by the selection optical element OSn is generated. And the zero-order beam LBnz that is not diffracted. When the intensity of the incident light beam LB is set to 100%, and the decrease due to the transmittance of the selection optical element OSn is neglected, the intensity of the diffracted light beam LBn is about 80% at most, and the remaining 20% becomes 0. The intensity of the secondary beam LBnz. The zero-order light beam LBnz passes through the condensing lens Ga and the collimator lens Gb, and is further absorbed by the absorber TR by the selection optical element OSn in the subsequent stage. The light beam LBn (parallel light beam) which is deflected toward the -Z direction by a diffraction angle corresponding to the frequency of the high frequency of the drive signal DFn passes through the condensing lens Ga and faces the incident mirror IMn provided on the surface Ps. The front focus position of the condensing lens Ga is optically conjugate with the diffraction point in the selection optical element OSn, so that the light beam LBn from the condensing lens Ga toward the incident mirror IMn is eccentric from the optical axis AXb and the light The axis AXb travels in parallel, and converges (converges) in such a manner that the position of the surface Ps becomes a beam waist. The position of the beam waist is set so as to be optically conjugate with the spot light SP projected onto the substrate P by the drawing unit Un.

By arranging the reflection surface of the incident mirror IMn or its vicinity on the surface Ps, the light beam LBn diffracted by the selection optical element OSn is reflected by the incident mirror IMn in the -Z direction and transmitted through the collimator lens Gc. The optical axis AX1 (see FIG. 2) is incident on the drawing unit Un. The collimator lens Gc forms a light beam LBn that converges/diverges by the condensing lens Ga to form a parallel beam coaxial with the optical axis (AX1) of the collimator lens Gc. The diameter of the light beam LBn formed as a parallel beam by the collimator lens Gc is substantially the same as the first diameter. The rear side focus of the condensing lens Ga and the front side focus of the collimator lens Gc are disposed on or near the reflecting surface of the incident mirror IMn within a predetermined allowable range.

As described above, when the front focus position of the condensing lens Ga is optically conjugate with the diffraction point in the selection optical element OSn, and the entrance mirror IMn is disposed on the surface Ps, which is the rear focus position of the condensing lens Ga, The frequency of the drive signal DFn of the optical element OSn is changed by ±ΔFs from the predetermined frequency, whereby the eccentricity (shift amount) of the condensed point on the surface 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. The shift amount (|ΔSFp|) is subjected to the optical system of the maximum range of the deflection angle of the selection optical element OSn itself, the size of the reflection surface of the incident mirror IMn, and the polygon mirror PM in the drawing unit Un (relay) The magnification of the system, the width of the reflection 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 can be applied to the substrate P of the spot light SP The effective size (diameter) or the extent of the pixel size (Pxy) defined on the depiction data is adjusted. Thereby, it is possible to accurately and quickly correct the superimposition error of the new pattern drawn on the substrate P by each of the drawing units Un and the pattern formed on the substrate P, or to draw on the substrate P by each of the drawing units Un. The joint error between the new patterns on the top.

Next, the reproducibility of the generation timing of the origin signal SZn from the origin sensors (the beam light-emitting system 60a and the beam light-receiving system 60b) configured as shown in Figs. 3 and 4 will be described with reference to Figs. 8 and 9 . (deviation error) A method of measuring and calculating. This measurement or calculation can be performed by a processor (CPU (Central Processing Unit)) or the like in the drawing control device 200 shown in FIG. 6, and the origin signal SZn can be transmitted to an external waveform measuring device or the like. Implementation. 8 is a plan view of the polygon mirror PM of the eight faces shown in FIG. 3 or FIG. 4, where the reproducibility of the origin signal SZn generated as shown in FIG. 5(B) is obtained for each of the eight reflecting surfaces RP. Therefore, the eight reflection surfaces RP and the rotation direction (clockwise direction) of the polygon mirror PM can be reversed to be RPa, RPb, RPc, RPd, RPe, RPf, RPg, and RPh. Further, on the upper surface (or lower surface) of the polygon mirror PM, a rotation reference mark Mcc 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 photo-electrical sensor (also referred to as a rotation detecting 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 reflection surface of the polygon mirror PM detected by the origin sensor must be specified, so that the detection signal (rotation reference mark Mcc) from the rotation detecting sensor is used as a reference. Each reflecting surface RPa~RPh of the polygon mirror PM is emitted.

Further, when measuring the reproducibility of the generation timing of the origin signal SZn, it is necessary to consider the influence of the speed variation (speed unevenness) of the polygon mirror PM. The speed variation of the polygon mirror PM can also be measured by the above-described rotation detecting sensor. However, in the present embodiment, the speed variation of the polygon mirror PM is measured based on the origin signal SZn. As described above, when the polygon mirror PM is rotated at 36,000 rpm, the polygon mirror rotation control unit in the drawing control device 200 performs servo control, and the polygon mirror PM is rotated 600 times in one second, and the design is designed. The rotation time TD of one rotation is 1/600 second (≒1666.667μS). Therefore, the frequency measurement is repeated from the origin time Tog of any one of the origin signals SZn by using the light source device LS for the pulse pulse of the frequency at which the oscillation frequency Fa of the pulse light is high (for example, twice or more). The actual rotation time TD of the origin of the 9 pulses at the time Tog. The polygon mirror PM is rotated at high speed with inertia, so the possibility of uneven speed during the rotation of one revolution is low. According to the characteristics of the servo control, there is a design rotation time in the period of several mS to several tens of mS. The TD slightly changed.

Fig. 9 is a view for explaining a method of measuring the reproducibility (deviation) of the generation timing of the origin signal SZn. Here, for simplification of description, a method of reproducibility of the origin time Tog2 of the origin signal SZn generated corresponding to the reflection surface RPa of the polygon mirror PM shown in FIG. 8 is exemplified, and the other reflection surfaces RPb to RPh are used. The measurement can also be performed in the same manner. In the case of FIG. 8, the origin time Tog1 generated at a timing before the origin time Tog2 can be obtained as the origin signal SZn generated corresponding to the reflection surface RPh of the polygon mirror PM. Therefore, in a state where the polygon mirror PM is rotated at a predetermined speed, the polygon mirror PM repeats the measurement of the origin time Tog1 corresponding to the reflection surface RPh a plurality of times (for example, 10 or more times) to correspond to The origin interval time ΔTmn (the number of rotations of n = 1, 2, 3, ...) from the origin time Tog2 of the next reflection surface RPa. In FIG. 9, for simplification of description, the origin signal Tog1 generated during the rotation of the polygon mirror PM by 7 turns is indicated by arranging the origin times Tog1 corresponding to the reflection surface RPh on the time axis in alignment. a) The waveform of each of 1~SZn(a)7.

Here, if the fluctuation of the rotational speed of the polygon mirror PM is assumed to be zero, the measured value of each of the fixed origin interval times ΔTmn is deviated. This deviation is the deviation amount ΔTe of the generation timing of the origin time Tog2 corresponding to the reflection surface RPa, and the reproducibility of the origin signal SZn is the standard deviation value of the plurality of origin times Tog2 distributed in the deviation amount ΔTe. It is obtained by σ or a 3σ value which is 3 times the standard deviation value σ. As described above, when the light source device LS oscillates 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 variation of the rotational speed of the polygon mirror PM (speed unevenness) is assumed to be zero, if the waveform measuring device that samples the signal waveform with a resolution of nanosecond or less is used, the origin signal is analyzed. When the waveform of SZn is attempted to measure the rotation time of the polygon mirror PM (the time of one rotation), it is judged that the rotation time varies by the number of rotations by several nS. Therefore, it is necessary to measure the origin interval time ΔTmn (the number of rotations of n = 1, 2, 3, ...) measured in the manner of Fig. 9 corresponding to the polygon mirror PM in 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 view schematically showing a method of predicting the amount of time error caused by the speed variation of the polygon mirror PM. In the present embodiment, the origin interval time ΔTmn corresponding to each of the eight reflecting surfaces RPa to RPh is measured for each of the plurality of rotations of the polygon mirror PM. In FIG. 10, the initial position (the first origin time Tog) in the one rotation of the polygon mirror PM is schematically shown as the reflection surface RPa, and the polygon mirror PM is rotated two times from the reflection surface RPa. The waveform of the origin signal SZn. Here, the origin interval time from the origin time Tog corresponding to the reflection surface RPa of the origin signal SZn to the origin time Tog corresponding to the adjacent reflection surface RPb is ΔTma, or less Similarly, the origin interval time from the adjacent reflecting surface RPb to the reflecting surface RPc is ΔTmb, and the origin interval time from the adjacent reflecting surface RPh to the reflecting surface RPa is ΔTmh. In the first week of the polygon mirror PM, each of the origin times Tog generated corresponding to each of the eight reflecting surfaces RPa to RPh is set as a starting point, and each of the reflecting surfaces RPa to RPh of the polygon mirror PM is measured. The rotation time TDa, TDb, ... TDh. Each of the rotation times TDa to TDh can also be obtained by using the total of the eight origin interval times ΔTma to ΔTmh corresponding to each of the eight reflection surfaces RPa to RPh. Each of the rotation times TDa to TDh (or the origin interval time ΔTma to ΔTmh) is repeatedly measured while the polygon mirror PM is rotated, for example, by N turns. Thereby, the data of each of the rotation times TDa to TDh counted by the origin time Tog corresponding to each of the eight reflection surfaces RPa to RPh can be obtained by the N-cycle.

Next, the average rotation time ave(TDa)~ave(TDh) of each of the rotation times TDa to TDh obtained for the continuous N-turn is calculated. For example, the rotation time TDA corresponds to the number of rotations N (N = 1, 2, 3, ...) and is stored as TTa (1), TTa (2), TTa (3), ... TTa (N), and thus the average rotation time ave (TDa) can be obtained by [TDa(1)+TDa(2)+TDa(3)+,...+TDa(N)]/N.

Next, it is assumed that each of the origin interval times ΔTma to ΔTmh measured after the second lap shown in FIG. 10 includes an error caused by the influence of the speed variation of the rotation of the previous polygon mirror PM, for example, regarding The measured original interval time ΔTma after 2 laps is predicted to vary only by the ratio of the measured rotational time TDA to the average rotational time ave (TDa) in the previous rotation, and the predicted interval interval ΔTma is calculated. Tma'. At this time, the average interval time ave (ΔTma) of the N-1 origin interval times ΔTma measured in each rotation after the second rotation is obtained. Then, the ratio of the average rotation time ave (TDa) to the actually measured rotation time TDa is multiplied by the average interval time ave (ΔTma), and the prediction interval time ΔTma' after the correction speed variation amount is calculated. Thereby, the difference between the actually measured origin interval time ΔTma and the predicted interval time ΔTma′ is determined by setting a more accurate deviation amount (σ value) corresponding to the origin time Tog generated by the reflection surface RPa. . The amount of deviation of the origin time Tog of the origin signal SZn corresponding to each of the other reflecting surfaces RPb to RPh is also obtained by the same calculation. In this way, only by the interval of the origin time Tog of the measured origin signal SZn, that is, the origin interval time ΔTma~ΔTmh, the multi-face mirror PM can be obtained by repeating the plurality of rotations of the original mirror signal SZn. The accurate reproducibility (3σ value, etc.) of the error caused by the speed variation.

[Measurement example]

As an example, the focal length Fgs of the lens system GLb in the beam receiving system 60b of the origin sensor is set to be about the same as the focal length fo (for example, 100 mm) of the fθ lens system FT, and the photoelectric conversion element DTo is disposed in the lens system. The focus of the GLb is at a position of Fgs, and the polygon mirror PM is rotated at about 38000 rpm, and the origin signal SZn (original moment) generated corresponding to each of the reflection surfaces RPa to RPh of the polygon mirror PM is measured by the method of FIG. After the reproducibility of Tog2), the results as shown in Fig. 11 can be obtained. In Fig. 11, the horizontal axis represents each position between the measured reflecting surfaces (RPa → RPb, RPb → RPc, ... RPh → RPa), and the vertical axis represents the difference between the reflecting surfaces after the correction of the variation of the rotational speed. The interval time ΔTma~ΔTmh (μS). In the present embodiment, the interval time ΔTma~ΔTmh is used to store the waveform data of the origin signal SZn continuously generated by the polygon mirror PM by 10 turns using a digital waveform memory device having a sampling frequency of 2.5 GHz (0.4 nS). And the waveform data is analyzed and measured.

As shown in Fig. 11, the interval time ΔTma~ΔTmh after the correction of the variation of the rotational speed is varied between 197.380 μS and 197.355 μS. When the polygon mirror PM is precisely rotated at a rotational speed of 38,000 rpm, the calculation interval time ΔTma to ΔTmh is 197.368 μS. The deviation of the interval time ΔTma to ΔTmh is, for example, not exactly 135 degrees, or the apex angle of each of the eight apex angles formed by the adjacent reflection surfaces of the respective reflection surfaces RPa to RPh of the polygon mirror PM. The distance from the rotation axis AXp to the respective reflection surfaces RPa to RPh is not precisely caused by a shape error in machining or the like. Further, the deviation of the interval time ΔTma to ΔTmh is also generated in accordance with the degree of eccentricity error of the polygon mirror PM with respect to the rotation axis AXp. In Fig. 11, the 3σ value calculated from the distribution of the deviations of the intervals ΔTma to ΔTmh is 2.3 nS to 5.9 nS. 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 three pulses or more is generated with respect to the scanning position of the spot light. As described above, when the diameter Φ of the spot light SP is 4 μm, the 1-pixel size Pxy is set to 4 μm square on the substrate P, and the 1-pixel amount is plotted with 2 pulses of the spot light SP, if 3σ is used, A value of about 6 nS means that the position of the pattern drawn along the drawing line SLn causes a deviation of about 5 μm (accurately, 4.8 μm) in the main scanning direction.

When the focal length of the fθ lens system FT is set to fo, and the distance of the pulse interval of the spot light SP on the substrate P (1/2 of the spot diameter) is ΔYp, the multi-face corresponding to the pulse interval distance ΔYp The angle change Δθp of the mirror PM (reflecting surface) becomes Δθp ≒ ΔYp/fo. On the other hand, when the moving distance of the laser beam Bgb (the spot light SPr) on the photoelectric conversion element DTo corresponding to the angle change Δθp is ΔYg, the lens according to the beam receiving portion (beam receiving system) 60b side is used. The focal length of the system GLb is Fgs, and the moving distance ΔYg becomes ΔYg ≒ Δθp × Fgs. The accuracy of the origin time Tog of the origin signal SZn is preferably an accuracy (resolution) corresponding to 1/2 or less of the pulse interval distance ΔYp of the spot light SP, so that the laser beam Bgb on the photoelectric conversion element DTo is made. The scanning speed of (spot light SPr) is increased to about twice the scanning speed of the spot light SP on the substrate P. That is, it should be set to ΔYg≒2. △ Yp relationship. Therefore, in the present embodiment, the focal length Fgs of the lens system GLb is set to about twice the focal length fo of the fθ lens system FT, and of course, it may be twice or more.

Fig. 12 is a view showing another reciprocating unit having the same configuration as that of the drawing unit Un actually measured in Fig. 11, and changing the focal length Fgs of the lens system GLb to Fgs ≒ 2 × fo, and measuring the reproducibility in the same manner as in Fig. 11 And the result. The vertical axis and the horizontal axis of Fig. 12 are the same as those of Fig. 11, but the scale of the scale of the vertical axis of Fig. 12 is 2 nS (5 nS in Fig. 11). The scanning speed of the spot light SPr on the photoelectric conversion element DTo is about twice the scanning speed of the spot light SP on the substrate P, and the 3σ is calculated based on the distribution of the deviation of each of the intervals ΔTma to ΔTmh. The value is 1.3 nS to 2.5 nS, which is approximately half that of the case of FIG. Therefore, in this case, when the diameter Φ of the spot light SP is 4 μm, the 1-pixel size Pxy is set to 4 μm square on the substrate P, and the 1-pixel amount is plotted with 2 pulses of the spot light SP. The deviation of the position of 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 onto the reflection surfaces RPa to RPh of the polygon mirror PM is set to have a predetermined thickness (for example, a diameter of 1) as the direction of rotation with respect to the reflection surfaces RPa to RPh. The parallel light beam of ~2 mm or more can reduce the influence of the roughness (polishing trace, etc.) of the surface of each of the reflecting surfaces RPa to RPh, and can accurately detect the angular change of the average surface. On the other hand, the diameter of the spot light SPr of the reflected light beam Bgb condensed on the photoelectric conversion element DTo is based on the width dimension of the light receiving surfaces PD1 and PD2 in the scanning direction of the light beam, and the inconvenience between the light receiving surfaces PD1 and PD2. Set appropriately according to the width. In order to obtain the signal waveform as shown in Fig. 5 [A], the diameter of the scanning direction of the spot light SPr is set to a condition that the width of the smaller one of the light receiving surfaces PD1, PD2 is smaller and the width of the less sensitive band is larger. Therefore, the focal length Fgs of the lens system GLb into which the reflected light beam Bgb is incident is set to satisfy the above condition, and is set to be longer than the focal length fo of the fθ lens system FT.

Further, since the intensity distribution in the cross section of the light beam Bga radiated from the semiconductor laser light source LDo shown in FIG. 4 is an elliptical shape having an aspect ratio of about 1:2, it is preferable to make the long axis direction of the elliptical shape and the polygon mirror PM. The rotation directions (main scanning directions) of the respective reflecting surfaces RPa to RPh match, and the short-axis direction of the elliptical shape coincides with the direction of the rotation axis AXp of the polygon mirror PM. In this way, even if the heights of the respective reflecting surfaces RPa to RPh of the polygon mirror PM (the size of the direction of the rotation axis AXp) are small, the light beam Bga can be efficiently 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 larger than the number of openings (NA) in the non-scanning direction, so that the scanning direction of the spot light SPr (the direction across the light receiving surfaces PD1 and PD2 in FIG. 5) can be improved. And make the contrast sharper.

Further, as the photoelectric conversion element DTo, instead of the magnitudes of the output signals STa and STb from the two light receiving surfaces PD1 and PD2, the magnitude of the origin signal SZn may be generated as shown in FIG. The signal level of the light receiving surface is compared with the reference voltage to generate the type of the origin signal SZn. In the case of this type, the reproducibility of the origin point Tog of the origin signal SZn has a steeper slope (the shorter the response time) of the rising or falling portion of the signal waveform, and the better the possibility, so it is preferable to make the crossing The scanning speed of the spot light SPr of the slit-shaped light receiving surface is faster than the scanning speed of the spot light SP for drawing, and the spot light SPr is concentrated by the lens system GLb as small as possible to increase the intensity per unit area.

In addition, the origin detecting sensor (the lens system GLb and the photoelectric conversion element DTo) of the present embodiment shown in FIG. 3 is an origin detecting beam that is projected from a light source different from the drawing (processing) light beam LBn. The reflected beam Bgb on the polygon mirror PM of Bga is photodetected. However, in the arrangement relationship of FIG. 3, after the reflection surface RPa of the polygon mirror PM has just become the angular position of RPa', the drawing light beam LBn is in a state where it is not incident on the fθ lens system FT (blank period), but there is incident During the period to the lens system GLb. Between the blank periods, the drawing light beam LBn is controlled so as not to enter the drawing unit Un by the pulse oscillation of the light beam LB from the light source device LS or the selection of the optical element OSn. Therefore, even in the blank period, the selection optical element OSn can be turned on while the drawing light beam LBn is incident on the lens system GLb, and the light beam LB can be pulse-oscillated from the light source device LS at the oscillation frequency Fa. 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 in the blank period can be used as the origin detecting light beam.

Further, the tendency of the deviation between the intervals ΔTma to ΔTmh shown in FIG. 12 and the interval ΔTma to ΔTmh shown in FIG. 11 above is large in the case of nanoseconds. It is assumed that the individual difference (machining tolerance) or the eccentricity error at the time of rotation differs in the tendency of the angular error of the apex angles between the polygon mirrors PM used in the actual measurement of the reproducibility of each of FIG. 11 and FIG. As shown in the actual measurement example of Fig. 11 or Fig. 12, the tendency or degree of the machining tolerance or eccentricity error of the polygon mirror PM may be different for each drawing unit Un(U1~U6), and the deviation of the interval time ΔTma~ΔTmh The error is also different for each drawing unit Un (U1~U6). Therefore, in the present embodiment, the deviation error of the interval time ΔTma to ΔTmh generated by the machining tolerance or eccentricity error of the polygon mirror PM or the shape deformation of the polygon mirror PM due to the temperature change is reduced. In response to the influence, 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 reflection surfaces RPa to RPh of the polygon mirror PM. In other words, the interval time ΔTma~ΔTmh of the origin time Tog of the origin signal SZn generated by each of the reflection surfaces RPa to RPh of the polygon mirror PM is corrected by the signal processing so as to be equal to the polygon mirror PM. The time of one revolution is roughly equal.

13 is a view showing a state in which a spot light SP of an average of two pulses per pixel is superimposed on the sub-scanning direction in the main scanning direction by a half of the spot size Φ and a continuous pattern of five pixels in the main scanning direction. Figure. In FIG. 13, the origin time Tog of the origin signal SZn generated by each of the reflection surfaces RPa to RPh of the polygon mirror PM is set as the starting point, and the pattern of the 5-pixel amount is started after the fixed delay time TD. . Further, the tendency of the deviation of the generation timing (original time Tog) of the origin signal SZn in Fig. 13 (the deviation of the interval time ΔTma to ΔTmh) is shown as an example in the case of Fig. 12 . As shown in FIG. 13, when the pattern of 5 pixels drawn by the spot light SP of the light beam LBn scanned by the reflecting surface RPa of the polygon mirror PM is used as a reference, the other reflecting surfaces RPb to RPh of the polygon mirror PM are used. The pattern of the five pixels depicted by the spot light SP of the light beam LBn scanned by each of them is deviated in the main scanning direction. Therefore, the edge of the drawn pattern extending in the sub-scanning direction is in units of pixels (amount of 1 to 2 pixels). The number of pixels of the 蜿蜒 corresponds to the line width of the pattern to be drawn (the number of pixels in the main scanning direction), and corresponds to the deviation of the interval time ΔTma~ΔTmh. Therefore, when the size of one pixel is set to 4 μm square on the substrate P, if a pattern having a minimum line width of 8 μm (amount of two pixels) is continuously drawn in the sub-scanning direction, the exposed linear pattern is formed. It was observed as a pattern which was greatly smeared with a line width.

Fig. 14 is a graph schematically showing a graph of characteristics of the actual measurement example of Fig. 12, and RPa/b~RPh/a of the horizontal axis respectively indicate respective positions between the reflection faces of the horizontal axis of Fig. 12 (RPa → RPb, RPb → RPc, ... RPh → RPa), and the vertical axis represents the same origin interval time ΔTma to ΔTmh (μS) as in Fig. 12 . In the reference time Tsr in Fig. 14, when the polygon mirror PM of the eight faces is precisely rotated at a rotational speed of 38,000 rpm, the time required to rotate 45 degrees is 197.368 μS. Further, the times Tab, Tbc, Tcd, Tde, Tef, Tfg, Tgh, and Tha of Fig. 14 are intervals of the center of the 3σ value which is three times the standard deviation shown in Fig. 12 . There is also an error in the rotational speed of the polygon mirror PM during the actual measurement. Therefore, the average value obtained by dividing the total value of the interval times Tab, Tbc, Tcd, Tde, Tef, Tfg, Tgh, and Tha by 8 is set as the actual reference time Tsr. '.

Therefore, in the present embodiment, each of the origin interval times ΔTma to ΔTmh of the origin signal SZn outputted with the characteristics as shown in Fig. 14 is corrected by the delay circuit so as to coincide with the reference time Tsr'. . Fig. 15 is a timing chart showing a state in which the origin signal SZn is generated by correcting the origin signal SZn. In FIG. 15, the period from the origin time Tog generated in the origin signal SZn corresponding to the reflecting surface RPa of the polygon mirror PM to the origin time Tog corresponding to the next reflecting surface RPb is representatively shown. The state of the correction is corrected, but the other reflection surfaces RPb to RPh are also corrected in the same manner. The origin time Tog corresponding to each of the reflection surfaces RPa and RPb of the origin signal SZn is generated as in the case of the interval time Tha, Tab, Tbc, as shown in FIG. Here, when the origin time Tog corresponding to the reflection surface RPa is set as the starting point, the origin time Tog' corresponding to the reflection surface RPa of the corrected origin signal SZn' (correction origin signal SZn') is The delay time ΔToa is adjusted from the origin time Tog′ corresponding to the previous reflection surface RPh to the reference time Tsr′. Further, the origin time Tog' corresponding to the reflection surface RPb of the corrected origin signal SZn' is adjusted by the delay time Δ from the origin time Tog' corresponding to the previous reflection surface RPa to the reference time Tsr'. Produced by Tob. Similarly, the origin time Tog' of the corrected origin signal SZn' corresponding to each of the other reflecting surfaces RPc to RPh is also corrected with respect to each of the previous reflecting surfaces RPb to RPg. The origin time Tog' of the point signal SZn' becomes the reference time Tsr', and only the delay times ΔToc, ΔTod, ΔToe, ΔTof, ΔTog, ΔToh are corrected. The delay time ΔToa to ΔToh of each of the reflection surfaces RPa to RPh is obtained from the difference between the time interval Tab~Tha specified as shown in FIG. 14 and the reference time Tsr'.

Fig. 16 is a view showing an example of a configuration of a correction circuit (correction unit) for inputting the origin signal SZn from the photoelectric conversion element DTo and generating the corrected origin signal SZn' (correction origin signal SZn') as shown in Fig. 15. The correction circuit is provided as part of the drawing control device 200 shown in FIG. In FIG. 16, the correction circuit has a counting circuit 210 that counts a clock signal CCK set to a frequency higher than a frequency Fa (400 MHz) of the clock signal CLK from the light source device LS (for example, 800 MHz); The bit buffer 212 sets a preset value corresponding to each of the interval times Tab~Tha to the counting circuit 210; and a shifter control circuit 214 that controls the shifting action of the shift register 212 (temporary storage) Choice of the device). Further, in the present embodiment, the sensor 220 and the detection circuit 222 are provided. The sensor 220 performs photoelectric detection on the reflected light of the rotation reference mark Mcc shown in FIG. 8, and the detection circuit 222 is based on the sense of the sense The signal of the detector 220 generates a logic level rotation pulse signal (1 pulse in the polygon mirror PM to 1 circle) Sj. The shifter control circuit 214 outputs a shift signal Sff (address designation signal) starting from the reflection surface RPa of the polygon mirror PM to the shift register 212 based on the rotation pulse signal Sj and the origin signal SZn. The shift register 212 has eight register 212A corresponding to the eight reflection surfaces RPa to RPh, and the eight registers 212A are connected in the form of a ring shift register, in response to the shift signal Sff. The preset values held in the registers are sequentially shifted to the adjacent registers. The output of one of the eight registers 212A from the shift register 212 is applied to the counting circuit 210.

The counting circuit 210 subtracts the pulse from the shift register 212 in response to the reset signal RST in response to the pulse of the clock signal CCK from the origin time Tog of the origin signal SZn generated corresponding to the reflective surface RPa. The preset value (for example, ΔToa) generates a pulse-like origin signal SZn' at the instant when the count value becomes zero. The counting circuit 210 inputs the origin signal SZn' as the reset signal RST, and reads it in response to the shift signal Sff after a fixed time (not reaching the reference time Tsr') from the origin time Tog' of the origin signal SZn'. A preset value (for example, ΔTob) from the shift register 212 of only one shift is set and set. With this operation, the corrected origin signal SZn' outputted from the counter circuit 210 is a substantially fixed reference time Tsr corrected by the deviation of the interval time Tab~Tha of the reflection surfaces RPa to RPh of the polygon mirror PM. 'Record origin time Tog'.

Furthermore, the preset values memorized by each of the eight registers 212A of the shift register 212 are memorized in the memory portion in the drawing control device 200, and are read out therefrom for preset. The interval time Tab~Tha and the reference time Tsr' shown in FIG. 14 are different according to the rotational speed VR of the polygon mirror PM. Therefore, the characteristics as shown in FIG. 12 and FIG. 14 are measured in advance for each different rotational speed VR. The preset value corresponding to each of the delay times ΔToa to ΔToh corresponding to the reference time Tsr' of each rotational speed VR is determined and stored in the form of a table in the memory unit in the drawing control device 200. Therefore, when the rotational speed VR of the polygon mirror PM is changed from the standard value (for example, 38000 rpm) during the drawing operation, the delay time ΔToa to ΔToh corresponding to the rotational speed VR of the polygon mirror PM after the change is advanced. The set value is read from the table of the memory unit in the drawing control device 200, and is set in the register 212A of the shift register 212. The set of preset values corresponding to the delay times ΔToa to ΔToh stored in the table in the drawing control device 200 is, for example, based on the polygon mirror PM in a state of 2000 rpm each time, for example, 40,000 rpm, 38,000 rpm, 36,000 rpm, etc. The rotation speed VR is made by actually measuring the data, and the preset value of the delay time ΔToa~ΔToh corresponding to the rotation speed VR during the period can also be obtained by linear interpolation.

According to the above embodiment, by using the correction origin signal SZn' for the start of the drawing, the reproducibility of the drawing start point is improved, and the origin time Tog' of each of the reflecting surfaces RPa to RPh of the polygon mirror PM is Since the deviation is reduced, the deviation of the absolute position in 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, when a plurality of drawing units Un are provided adjacent to each other, the temperature in each drawing unit Un is likely to rise. It is also possible to suppress the temperature rise by the air conditioning or the temperature adjustment of the drawing unit Un, but to reduce the noise (wind noise) generated when the polygon mirror PM is rotated at a high speed, the housing or the polygon mirror PM is provided for each drawing unit Un. There is a cover around it, so there is a case where the air conditioner or the temperature adjustment does not function effectively. In other words, it is difficult to satisfactorily suppress the change in the temperature of the air around the polygon mirror PM or around the origin sensor (the beam light transmitting portion 60a and the light beam receiving portion 60b). When the base material of the polygon mirror PM is made of aluminum in order to reduce the weight, the state of the reflection surface of the polygon mirror PM may be deformed in the submicron order depending on the degree of such temperature change. In the case where the lens system GLa of the light beam transmitting unit (beam light transmitting system) 60a that generates the origin detecting light beam Bga is formed into a plastic (resin mold) in a unitary manner with the semiconductor laser light source LDo, According to the change in the ambient temperature, the light beam Bga directed toward the polygon mirror PM easily changes from a parallel state to a light beam having 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, the reproducibility of the origin signal SZn is lowered or the angle of the light beam Bga toward the polygon mirror PM is slightly shifted.

Therefore, in the present modification, a temperature sensor that precisely measures the temperature around the polygon mirror PM or the periphery of the origin sensor (the beam light transmitting portion 60a and the light beam receiving portion 60b) is provided, and the measured value is obtained in advance. The reproducibility of the origin signal SZn (3σ value) and the origin interval time ΔTma~ΔTmh (or the interval time Tab~Tha of FIG. 14) with respect to the temperature change coefficient, according to the temperature measured by the temperature sensor The preset value corresponding to each of the delay times ΔToa to ΔToh set in the shift register 212 of FIG. 16 is corrected. Thereby, it is possible to reduce the occurrence of a deviation in the main scanning direction due to the temperature change of the drawing unit Un at the start point of the drawing pattern.

[Modification 2]

17 is a view showing the configuration of the origin sensor of the second modification, and is an observation of the polygon mirror PM in the drawing unit Un and the optical axis AXf of the fθ lens system FT in the XY plane, and constitutes the origin sensor. The light beam transmitting unit 60a and the light beam receiving unit 60b are arranged to be arranged. In FIG. 17, the drawing light beam LBn is projected onto one of the reflecting surfaces RP of the polygon mirror PM, and one adjacent (first one) reflecting surface RPb of the reflecting surface RPa of the polygon mirror PM is projected from The laser beam (origin detection beam) Bga of the beam light transmitting portion 60a. Moreover, the angular position of the reflecting surface RPa in FIG. 17 indicates a state immediately before the point where the spot light SP of the drawing light beam LBn is located at the drawing start point of the drawing line SLn. Here, the reflecting surface RP (RPa) of the polygon mirror PM is disposed so as to be located on the incident pupil plane orthogonal to the optical axis AXf of the fθ lens system FT. Strictly speaking, the chief ray of the light beam LBn incident on the fθ lens system FT becomes the angular position of the reflection surface RP (RPa) at the moment of being coaxial with the optical axis AXf, and is the main beam of the light beam LBn from the mirror M23 toward the polygon mirror PM. The reflection surface RP (RPa) is set at a position where the light intersects the optical axis AXf. Further, the distance from the main surface of the fθ lens system FT to the surface of the substrate P (the condensed point of the spot light SP) is the focal length fo.

The light beam Bga from the beam light transmitting portion 60a is projected to the reflecting surface RPb of the polygon mirror PM as a parallel light beam having a wavelength region which is non-photosensitive to the photosensitive functional layer of the substrate P by the lens system GLa similar to that of FIG. . The reflected light beam Bgb of the laser beam Bga reflected on the reflecting surface RPb faces a mirror (reflecting optical member) MRa having a reflecting 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 reflecting surface RPb of the polygon mirror PM. The reflected light beam Bgd of the light beam Bgc reflected on the reflecting surface RPb is received by the light beam receiving portion 60b. The light beam receiving unit 60b is attached to the reflecting surface RPb (and the other reflecting surfaces RP) of the polygon mirror PM at a specific angular position in the XY plane, and the light beams Bga, Bgb, Bgc, and Bgd travel as shown in FIG. The portion 60b outputs a pulse-like origin signal SZn. In FIG. 17, the light beam Bga is simply shown as a line, but actually, 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 represented as a line, but actually becomes a parallel light beam having a predetermined width in the XY plane, and the light beam Bgd corresponds to the rotation of the polygon mirror PM to the light beam receiving portion 60b as an arrow Aw. Scan as usual. Similarly to FIG. 4, the light beam receiving unit 60b has a photoelectric conversion element DTo that outputs an origin signal SZn when receiving the light beam Bgd, and a lens system GLb that condenses the light beam Bgd on the photoelectric conversion element DTo to a spot light SPr. .

In the second modification, as shown in FIG. 17, the mirror MRa is used, and the origin detecting beam Bga is received by the photoelectric conversion element DTo after the reflection surface RP (RPb) of the polygon mirror PM is reflected twice. The spot light SPr of the beam Bgd. Therefore, the scanning speed Vh of the spot light SPr on the light receiving surfaces PD1 and PD2 and the reflection surface RP (RPb) of the polygon mirror PM can be reflected once and received by the photoelectric conversion element DTo. The situation is more than twice as high. Thereby, the scanning speed Vh of the origin detecting light beam Bgd (the spot light SPr) on the photoelectric conversion element DTo can be increased to 2 as compared with the scanning speed Vsp of the drawing light beam LBn (the spot light SP) on the substrate P. In the same manner as in the first embodiment, the reproducibility of the origin signal SZn can be improved. However, in the second modification, it is not necessary to make the focal length Fgs of the lens system GLb provided in the light beam receiving unit 60b twice or more the focal length fo of the fθ lens system FT, and even if the same focal length is used, the point can be made. The scanning speed Vh of the light SPr is twice the scanning speed Vsp of the spot light SP.

Further, in the second modification, the origin detecting light beam Bga is projected on the one reflecting surface RPb before the reflecting surface RPa of the polygon mirror PM to which the drawing light beam LBn is projected. Therefore, in the case of the origin sensor as shown in FIG. 17, the setting is made such that the reflecting surface RPa is set such that the spot light SP of the drawing light beam LBn is slightly ahead of the drawing start point of the drawing line SLn. At the instant of the angle, the origin signal SZn from the beam receiving portion 60b of Fig. 17 becomes the origin time Tog. In this manner, even if the difference between the drawing light beam LBn and the origin detecting light beam Bga is reflected by the different reflecting surfaces of the polygon mirror PM, the corrected origin signal SZn' can be generated as in the first embodiment. The case where the starting point of the drawing pattern is deviated in the main scanning direction is reduced.

[Second Embodiment]

In the second embodiment, the reference pattern formed on the outer peripheral surface of the rotating cylinder DR shown in FIG. 1 is scanned by the spot light SP of the light beam LBn projected from the drawing unit Un, and the light detector DTc shown in FIG. 2 is used. The photoelectric signal obtained by detecting the reflected light generated from the reference pattern confirms the reproducibility of the origin signal SZn or the origin interval time ΔTma~ΔTmh (or the interval time Tab~Tha of FIG. 14), or sets the delay time Toa ~Toh. Further, for example, Japanese Laid-Open Patent Publication No. 2015/152217 discloses that a reference pattern is provided on the outer peripheral surface of the rotating cylinder DR, and the photodetector DTc in the drawing unit Un detects the specular reflected light generated when the reference pattern is scanned by the spot light SP. The composition.

FIG. 18 is a view showing an example of a waveform of the photoelectric signal Sv generated from the photodetector DTc when the line formed on the outer circumferential surface of the rotating cylinder DR and the gap-shaped reference patterns PTL1 and PTL2 are scanned by the spot light SP. The reference pattern PTL1 is a linear pattern having a line width of 20 μm in the main scanning direction and a low reflectance extending in the sub-scanning direction, and the reference pattern PTL2 has a line width of 20 μm in the main scanning direction and extends in the sub-scanning direction. Linear pattern with high reflectivity. When the reference patterns PTL1 and PTL2 are scanned by the spot light SP, the intensity of the specular reflected light generated from the reference pattern PTL1 becomes low, and the intensity of the specular reflected light generated from the reference pattern PTL2 becomes high. Since the fθ lens system FT is telecentric, the specular reflected light from the reference patterns PTL1 and PTL2 is reversed along the optical path of the drawing light beam LBn of FIG. 2 and reaches the polarization beam splitter BS1. Although not shown in FIG. 2, a condensing lens that condenses the specular reflected light (the same parallel beam as the light beam LBn) transmitted through the polarization beam splitter BS1 to the photodetector DTc is provided. Thereby, the outer peripheral surface of the substrate P or the rotating cylinder DR is conjugate with the light receiving surface of the photodetector DTc, and a conjugate image of the spot light SP projected onto 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 is at 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.

The waveform change of the signal Sv from the photodetector DTc is digitally converted by using the clock signal CLK from the light source device LS that causes the spot light SP to illuminate the pulse light, or the sampling clock signal obtained by multiplying the clock signal CLK. And analyzing, by which the reference pattern PTL1 can be measured based on the scanning position of the spot light SP based on the origin time Tog of the origin signal SZn (or the origin time Tog' of the corrected origin signal SZn'). The edge position of PTL2 extending in the sub-scanning direction.

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

Fig. 20 is a timing chart showing an example of the deviation of the generation timing of the origin time Tog' (or the origin time Tog) of the measurement origin signal SZn' (or the origin signal SZn) using the circuit configuration of Fig. 19. In the present embodiment, the outer peripheral surface of the rotating cylinder DR is formed 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, as shown in FIG. Reference patterns PTL1, PTL2. In the present embodiment, the rotation angle of the rotary cylinder DR is set to be stationary so that the reference patterns PTL1 and PTL2 are positioned on the drawing line SLn.

As shown in FIG. 20, after the fixed delay time ΔTD from the origin time Tog' of the self-correcting 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 start to paint. Further, before the start of the pulse oscillation of the light beam LB, the selection optical element OSn corresponding to the target drawing unit Un is also turned on. While the selection optical element OSn is in the ON state and the light beam LB is supplied as the light beam LBn to the target drawing unit Un, the spot light SP of the light beam LBn is set to a range as long as the reference patterns PTL1 and PTL2 are traversed. During this on state, the light beam LB from the light source device LS continuously oscillates at a frequency Fa. When the spot light SP scans the surface of the rotating cylinder DR immediately after the delay time ΔTD, the photoelectric signal Sv from the photodetector DTc changes level in the waveform as shown in FIG. The address generation unit 244 generates an address value which is sequentially incremented in response to the clock pulse of the clock signal CLK2 from the time Tu1 after the delay time ΔTu from the origin time Tog′, and the waveform memory unit 242 is designated. The address value sequentially stores the digital value (the value corresponding to the level of the signal Sv) from the A/D conversion unit 240. Here, the delay time ΔTu is set to ΔTu>ΔTD, and is set to a time before the point light SP reaches the reference patterns PTL1 and PTL2.

The address generation unit 244 and the waveform memory unit 242 convert the waveform of the signal Sv during a fixed period from the time Tu1 to the time Tu2, that is, the period in which the spot light SP scans the distance including the reference patterns PTL1 and PTL2. The data is stored in the waveform memory unit 242 with the time resolution of the clock signal CLK2. The waveform memory operation as described above is performed every time the scanning beam LBn is scanned by the designated one reflecting surface RP (for example, RPa) of the polygon mirror PM, and the waveform memory unit 242 stores a plurality of borrowings. Waveform data from time Tu1 to 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 stored plurality of waveform data, and confirms whether or not the reproducibility of the origin time Tog' of the origin signal SZn' is within a predetermined specification. For this purpose, the waveform analysis unit 246 specifies the position (address position) that rises or falls in accordance with the edge positions of the reference patterns PTL1 and PTL2 in the waveform change of the signal Sv, and obtains each reference pattern PTL1 (low reflectance). At the midpoint position, the average position CTu (address position) of the midpoint position is obtained. The address value of one waveform data stored in the waveform memory unit 242 corresponds to the clock pulse of the clock signal CLK2. Therefore, the time from the time Tu1 to the average position CTu can be based on the period of the clock signal CLK2 and the self-time Tu1. The product of the number of addresses up to the average position CTu is converted, and the time ΔTPc from the origin time Tog' of the origin signal SZn' to the average position CTu is estimated. The waveform analysis unit 246 performs such analysis on each of the plurality of stored waveform data, and estimates a plurality of times ΔTPc. The waveform analysis unit 246 obtains a 3σ value based on the estimated standard deviation value σ of the deviation of the plurality of estimated times ΔTPc, and transmits the 3σ value to the drawing control device 200.

Further, whether or not each of the intervals Time Tab to Tha of the origin time Tog' of the corrected origin signal SZn' generated corresponding to each of the reflecting surfaces RPa to RPh of the polygon mirror PM is corrected to the reference time Tsr' is A circuit for counting the clock signal CLK2 is added to the circuit of FIG. 19, for example, an origin time Tog' corresponding to the reflection surface RPa of the polygon mirror PM in the correction origin signal SZn' and corresponding to the reflection The interval time of the origin time Tog' generated by the reflection surface RPb below the surface RPa is measured a plurality of times, and the average value thereof is obtained and sent to the drawing control device 200. The interval time between the other reflecting surfaces is also measured in the same manner, and the average value of the obtained interval time is sent to the drawing control device 200. The drawing control device 200 confirms whether or not each of the transmitted time intervals Tab~Tha is within the allowable range with respect to the reference time Tsr', and corrects the shift register 212 of FIG. 16 when there is an error of the allowable range or more. Set the delay time △ Toa ~ △ Toh.

According to the second embodiment described above, it is possible to suppress the deviation of the drawing start position caused by the temporal change of the corrected origin signal SZn' (or the original origin signal SZn before correction), and it is possible to stably stabilize for a long period of time. Implement pattern depiction. In the present embodiment, the reproducibility of the origin signal SZn' or the interval time Tab~Tha is confirmed using the reference patterns PTL1, PTL2 formed on the outer circumferential surface of the rotating cylinder DR, but the reference set on the substrate P may be detected. Patterns PTL1, PTL2. Further, a single sheet of the reference sheets PTL1 and PTL2 may be wound (for example, a glass sheet or a stainless steel sheet having the same thickness as the substrate P and having flexibility and less deformation). And fixed around the rotating cylinder DR.

[Third embodiment]

Fig. 21 is a view for explaining a method of testing exposure for correcting the accuracy of the original origin signal SZn' (or the original origin signal SZn before correction) in the third embodiment, and in the present embodiment, by the object 1 The 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 exposes a plurality of rectangular test patterns Tpt. However, in the present embodiment, the test pattern Tpt exposed to the line MPa among the plurality of test patterns Tpt arranged in the sub-scanning direction is controlled so as to be drawn only by the reflection surface RPa of the polygon mirror PM, and exposed to the line. The MPb test pattern Tpt is controlled in such a manner that it is drawn only by the reflection surface RPb of the polygon mirror PM. Similarly, in the same manner, the test pattern Tpt exposed to each of the rows MPc to MPh is controlled so as to be drawn by any of the reflection surfaces RPc to RPh of the polygon mirror PM. In other words, the test pattern Tpt is exposed by the spot light SP of the light beam LBn reflected by only one of the designated ones of the polygon mirror PM, and the substrate P is 1/8 of the transport speed at the time of normal exposure. The speed is transferred. Further, it is not necessary to arrange a plurality of test patterns Tpt in the main scanning direction in the lines MPa to MPh, but to test the pattern Tpt of each position (area) in the main scanning direction of the drawing line SLn for scanning the spot light SP. The shape is changed and configured.

The substrate P that has been subjected to the test exposure may be a one in which a single-piece PEN film having a small expansion and contraction, an extremely thin glass sheet, or a stainless steel sheet are neatly attached to the outer peripheral surface of the rotary cylinder DR. After the substrate P subjected to the test exposure is subjected to a development process or an etching process, the formation state of the edge portions Ef and Et extending in the sub-scanning direction of the test pattern Tpt is enlarged by an inspection device or the like. When the edge portions Ef and Et of the test pattern Tpt are deviated as shown in FIG. 13, for example, the reproduction of the origin time Tog' of the corrected origin signal SZn' corresponding to the reflection surface of the polygon mirror PM of the test pattern Tpt is reproduced. Sexual deterioration.

Further, as shown in FIG. 21, the group of eight rows MPa to MPh of the test pattern Tpt drawn by each of the eight reflecting surfaces RPa to RPh of the polygon mirror PM is repeatedly formed in the sub-scanning direction. Further, for example, it is specified that the center position of the first test pattern Tpt in the first row MPa and the second row MPa spaced apart from the first row MPa in the sub-scanning direction and the first test pattern Tpt are in the main scan. A straight line Lcc connected to the center position of the second test pattern Tpt at the same position in the direction, and measuring 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 The position error ΔYtt of the main scanning direction of the straight line Lcc. When the position error ΔYtt is precisely adjusted to the reference time Tsr' when the interval time Tab~Tha of the correction origin signal SZn' is precisely adjusted, the amount becomes substantially the same amount. However, in the case where the measured position error ΔYtt is deviated in the lines MPb to MPh, it means that the correction time of the interval time Tab~Tha is shifted to the reference time Tsr'. That is, the interval time Tab~Tha of the origin signal SZn before the correction is changed. By analyzing the position error ΔYtt, it is possible to estimate the fluctuation of the interval time Tab~Tha. Therefore, the drawing control device 200 corrects the delay times Toa to 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 original origin signal SZn' (or the original before correction) can be confirmed. The reproducibility of the origin time Tog' (or the origin time Tog) generated by each of the reflection surfaces RPa to RPh of the point signal SZn). Further, it is also possible to confirm the change in the deviation time interval Tab~Tha between the reflection surfaces RPa to RPh of the polygon mirror PM.

[Modification of Third Embodiment]

When the test exposure is performed as shown in Fig. 21, the rotary cylinder DR must be precisely rotated at a predetermined speed (1/8 of the normal speed), and in the test exposure, the rotary cylinder DR must also be made smaller than the central axis AXo. A slight displacement in the direction of extension (main scanning direction). However, it is difficult to suppress the positional variation in the main scanning direction of the rotary cylinder DR to the micron order or the submicron order.

Therefore, in the present modification, as shown in FIG. 22, the end portion in the direction in which the central axis AXo of the outer peripheral surface of the rotating cylinder DR extends is provided in a linear reference pattern PTL3 continuous in the circumferential direction. Further, a pattern detector DXa is provided which is set on an extension line of the odd-numbered drawing lines SL1, SL3, and SL5 in the Y-axis direction (main scanning direction), and includes a detection area Axv for detecting the reference pattern PTL3; The pattern detector DXb is set on an extension line of the even-numbered drawing lines SL2, SL4, and SL6 in the Y-axis direction (main scanning direction), and includes a detection area Axv for detecting the reference pattern PTL3. The pattern detectors DXa and DXb can measure a slight displacement in the Y-axis direction in the detection area Axv of the linear reference pattern PTL3 at a submicron level. Further, when the reference pattern PTL3 is not provided on the outer circumferential surface of the rotating cylinder DR, a reference plane orthogonal to the central axis AXo may be formed on the end surface portion in the direction in which the central axis AXo of the rotating cylinder DR extends, and the electrostatic capacitance type may be used. Or an optical non-contact gap sensor (line sensor) GSa, GSb measures 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, and SL5, and the gap is observed when viewed in the XZ plane. 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.

When the test exposure as shown in FIG. 21 is performed, the rotating cylinder DR (substrate) when each of the plurality of test patterns Tpt arranged in the sub-scanning direction is exposed is measured by the pattern detectors DXa, DXb or the gap sensors GSa, GSb. The value of the positional displacement in the Y-axis direction of P) is, for example, stored in the drawing control device 200. Further, when the positional relationship of the test pattern Tpt exposed to the substrate P in a matrix is measured by an inspection device or the like, the measured value of the Y-direction (main scanning direction) of the test pattern Tpt is corrected by the value of the positional displacement stored. Thereby, the error caused by a slight change in the position of the rotating cylinder DR (substrate P) in the Y-axis direction generated during the test exposure can be canceled, and the reflecting surface RPa corresponding to the polygon mirror PM can be accurately inspected. The reproducibility of the original origin signal SZn' (or the original origin signal SZn) generated by each of the RPh, and the origin interval between the reflection surfaces RPa to RPh of the polygon mirror PM can be checked with high precision. The change in the deviation of Tab~Tha.

[Fourth embodiment]

Fig. 23 is a partial cross-sectional view showing the rotary cylinder DR of the fourth embodiment. In the present embodiment, a small opening 50J (may be a depressed portion) is provided in one of the outer peripheral surfaces of the rotating cylinder DR, and the light beams from the drawing unit Un are vertically received by the light receiving surfaces PD1 and PD2. The photoelectric conversion element DTo as shown in FIG. 5 is set in the manner of LBn. In the present embodiment, instead of detecting the specular reflected light from the reference patterns PTL1 and PTL2 on the outer circumferential surface of the rotary cylinder DR as described in FIG. 20 above, the origin detection is directly detected by the photoelectric conversion element DTo provided in the rotary cylinder DR. The light beam Bgb (or the drawing light beam LBn) is used, and the reproducibility of the corrected origin signal SZn' (or the original origin signal SZn before correction) or the deviation of the origin interval time Tab~Tha is measured.

In the first embodiment shown in FIG. 3 above, the origin detecting sensor (the lens system GLb and the photoelectric conversion element DTo) detects the origin of the light source from the light source LBn different from the drawing (processing) beam LBn. Photodetection is performed by the reflected beam Bgb of the polygon B of the beam Bga. However, in the arrangement relationship of FIG. 3, after the reflection surface RPa of the polygon mirror PM becomes the angular position of RPa', the reflected light beam Bgb reflected by the reflection surface RPa is incident on the fθ lens system FT. The reflected light beam Bgb incident on the fθ lens system FT can be collected on the image plane side (the rotating drum DR side) of the fθ lens system FT in the same manner as the drawing light beam LBn. Therefore, in the present embodiment, the photoelectric conversion element DTo provided in the rotary cylinder DR as shown in FIG. 23 detects the reflected light beam Bgb of the origin detecting light beam Bga which is scanned by the polygon mirror PM and incident on the fθ lens system FT. . In the present embodiment, the substrate P is not supported by the rotating cylinder DR or the transparent region of the substrate P is supported by the outer peripheral surface of the rotating cylinder DR, and is performed by the photoelectric conversion element DTo provided in the rotating cylinder DR. measuring. In the present embodiment, the photoelectric conversion element DTo can receive both the origin detecting beam Bgb and the drawing light beam LBn in a state where the rotating cylinder DR is stopped. 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 detecting light beam Bgb. Therefore, for example, the time at which the point light of the origin detecting light beam Bgb is located at the center position of the light receiving surface of the photoelectric conversion element DTo of FIG. 23 and the corrected origin signal are used, for example, by using the multiplicative clock signal CCK shown in FIG. The interval between the origin time Tog' of SZn' (or the origin time Tog of the original origin signal SZn before correction) is counted, thereby detecting the corrected origin signal SZn' (or the origin signal before correction) Accuracy of SZn) (reproducibility, deviation of origin interval time Tab~Tha).

Claims (23)

 A beam scanning device that projects a processing beam for each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates about a rotation axis, and transmits the processing beam reflected by each of the plurality of reflecting surfaces to a scanning optical system Scanning the object to be irradiated, and having an origin detecting unit that generates an origin signal every time the plurality of reflecting surfaces of the rotating polygon mirror have a predetermined predetermined angle; and a correction unit that generates The corrected origin signal corrected by the correction value is a correction value corresponding to a deviation amount of the time interval of the origin signal generated corresponding to each of the plurality of reflecting surfaces.    The beam scanning device according to claim 1, further comprising a control unit that controls a timing of projection of the processing light beam toward the object to be irradiated based on the correction origin signal.    A beam scanning device according to claim 1 or 2, further comprising: a calculation unit that corrects an error accompanying a variation of a rotational speed of the rotating polygon mirror, and calculates a time interval of the origin signal The amount of deviation.    The beam scanning device of claim 1, wherein the origin detecting unit includes: a photodetector that receives a reflected beam of a detecting beam that is projected onto a reflecting surface of the rotating polygon mirror and generates the origin signal; a collecting optical system that converges the reflected beam of the detecting beam into a spot of the photodetector and traverses a scanning speed of the spot of the photodetector by rotation of the rotating polygon mirror The scanning speed of the processing beam on the object to be irradiated is faster.    The beam scanning device of claim 4, wherein the scanning optical system has the processing beam reflected by the plurality of reflecting surfaces of the rotating polygon mirror condensed into light on the object to be irradiated The refractive power of the point, the concentrating optical system comprising an optical element having a refractive power lower than that of the scanning optical system and concentrating the reflected beam of the detecting beam.    The beam scanning device of claim 5, wherein a focal length corresponding to a refractive power of the optical element of the collecting optical system is made longer than a focal length corresponding to a refractive power of the optical system for scanning.    The beam scanning device of claim 4, wherein the collecting optical system comprises: a reflecting optical member that reflects the first reflected beam of the detecting beam that is initially reflected by the reflecting surface of the rotating polygon mirror toward the rotating multi-faceted a reflecting surface of the mirror; and an optical element that causes the second reflected light beam that is reflected by the reflecting surface of the rotating polygon mirror to be incident second, and is collected by the photodetector as a light spot.    The beam scanning device according to any one of claims 4 to 7, wherein the correction unit uses one rotation of the rotating polygon mirror obtained from an interval of occurrence of the origin signal. The reference interval time divided by the number of reflection surfaces of the rotating polygon mirror is set, and a correction value corresponding to the deviation amount is set.    A pattern drawing device that projects a light beam for drawing by a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, and transmits the light beam for drawing reflected by each of the plurality of reflecting surfaces to scan The optical system scans the object to be irradiated, and draws a pattern on the object to be irradiated, and includes an origin detecting unit that is set to a predetermined angle every time the plurality of reflecting surfaces of the rotating polygon mirror are at a predetermined angle Generating an origin signal; the drawing control unit sets a start time point of the pattern drawing by the drawing light beam from a predetermined delay time from the generation of the origin signal; and a correction unit based on the plurality of Each of the reflecting surfaces is a correction value corresponding to a 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.    The pattern drawing device of claim 9, wherein the origin detecting unit includes: a photodetector that receives a reflected beam of a detecting beam that is projected onto a reflecting surface of the rotating polygon mirror and generates the origin signal; a collecting optical system that converges the reflected beam of the detecting beam into a spot of the photodetector and traverses a scanning speed of the spot of the photodetector by rotation of the rotating polygon mirror The scanning speed of the drawing light beam on the object to be irradiated is faster.    The pattern drawing device of claim 10, wherein the scanning optical system has the light beam for drawing reflected by each of the plurality of reflecting surfaces of the rotating polygon mirror condensed into light on the object to be irradiated The refractive power of the point, the concentrating optical system comprising an optical element having a refractive power lower than that of the scanning optical system and concentrating the reflected beam of the detecting beam.    The pattern drawing device of claim 11, wherein a focal length corresponding to a refractive power of the optical element of the collecting optical system is made longer than a focal length corresponding to a refractive power of the scanning optical system.    The pattern drawing device of claim 10, wherein the collecting optical system comprises: a reflecting optical member that reflects the first reflected beam of the detecting beam that is initially reflected by the reflecting surface of the rotating polygon mirror toward the rotating multi-faceted a reflecting surface of the mirror; and an optical element that causes the second reflected light beam that is reflected by the reflecting surface of the rotating polygon mirror to be incident second, and is collected by the photodetector as a light spot.    The pattern drawing device according to any one of claims 10 to 13, wherein the correction unit uses a rotation of the rotating polygon mirror corresponding to an interval of occurrence of the origin signal. The reference interval time divided by the number of reflection surfaces of the rotating polygon mirror is set, and a correction value corresponding to the deviation amount is set.    A pattern drawing device that projects a light beam for drawing by a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, and transmits the light beam for drawing reflected by each of the plurality of reflecting surfaces to scan The optical system scans the substrate supported by the supporting member, and draws a pattern on the substrate, and includes an origin detecting unit for each of the plurality of reflecting surfaces of the rotating polygon mirror to have a predetermined angle An origin signal is generated; the drawing control unit sets a start time point of the pattern drawing by the drawing light beam from a predetermined delay time from the generation of the origin signal; and a correction unit based on the plurality of Each of the reflecting surfaces is a correction value corresponding to a 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; and the measuring unit is measured by Generating a time point of the reflected light generated from the reference pattern when the drawing beam is formed on the support member or the reference pattern of the substrate, and the origin signal The time between the time points is generated, and the correction value corresponding to the deviation is obtained.    The pattern drawing device of claim 15, wherein the measuring portion 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 An optical signal corresponding to a change in reflectance of the reference pattern.    The pattern drawing device of claim 16, wherein the scanning optical system condenses the drawing light beam on the substrate into spot light, and the drawing light beam is caused by the point light using the rotating polygon mirror In the scanning direction, the light source device is pulse-oscillated while the point light is partially overlapped.    The pattern drawing device of claim 17, wherein the measuring portion has a waveform memory portion, and the waveform memory portion waveforms the photoelectric signals from the photodetector at a frequency higher than a frequency of the pulse oscillation of the light source device The changes are sampled.    A pattern drawing device that projects a light beam for drawing by a plurality of reflecting surfaces of a rotating polygon mirror that rotates around a rotation axis, and transmits the light beam for drawing reflected by each of the plurality of reflecting surfaces to scan The optical system scans the substrate supported by the supporting member, and draws a pattern on the substrate, and includes an origin detecting unit for each of the plurality of reflecting surfaces of the rotating polygon mirror to have a predetermined angle An origin signal is generated; the drawing control unit sets a start time point of the pattern drawing by the drawing light beam from a predetermined delay time from the generation of the origin signal; and a correction unit based on the plurality of Each of the reflecting surfaces is a correction value corresponding to a 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; and the measuring unit is provided a photoelectric conversion element supporting a part of the support surface of the member, and measuring the photoelectric signal obtained when the photoelectric conversion element is scanned by the drawing beam Generation time and the generation time point between the time point of origin of the signal, corresponding to the determined correction value to the deviation.    The pattern drawing device of claim 19, wherein the origin detecting unit includes: a photodetector that receives a reflected beam of a detecting beam that is projected onto a reflecting surface of the rotating polygon mirror and generates the origin signal; a collecting optical system that converges the reflected beam of the detecting beam into a spot of the photodetector and traverses a scanning speed of the spot of the photodetector by rotation of the rotating polygon mirror The scanning speed of the light beam on the substrate is faster than that of the drawing.    The pattern drawing device of claim 20, wherein the scanning light beam is incident on the scanning optical system before the drawing light beam is incident on the scanning optical system, with the rotation of the rotating polygon mirror being set. The photoelectric conversion element of the support member receives a spot of the detection beam that is condensed by the scanning optical system.    The pattern drawing device of claim 21, wherein the scanning optical system condenses the drawing light beam on the substrate into spot light, and the drawing light beam is caused by the point light using the rotating polygon mirror In the scanning direction, the light source device is pulse-oscillated while the point light is partially overlapped.    A method for checking the accuracy of a pattern drawing device for inspecting the accuracy of a pattern drawing device that projects a light beam for drawing on each of a plurality of reflecting surfaces of a rotating polygon mirror that rotates about a rotation axis to cause the plurality of light beams to be drawn The drawing light beam reflected by each of the reflecting surfaces is condensed into a spot light on the substrate supported by the supporting member through the scanning optical system, and is scanned in the main scanning direction, and the method includes the following stages: setting phase, response When the specific reflection surface of the rotating polygon mirror in the origin signal generated from the origin detecting portion becomes the predetermined angle when each of the plurality of reflecting surfaces of the rotating polygon mirror becomes a predetermined predetermined angle The specific origin signal is drawn by the scanning of the main scanning direction of the spot light by the specific reflecting surface; the drawing phase is repeatedly generated by the rotation of the rotating polygon mirror Between the intervals of the specific origin signals, the substrate is crossed at a distance smaller than the spot light from the main scanning direction. Moving in the scanning direction, the inspection pattern is drawn; in the repeating phase, the specific reflection surface of the rotating polygon mirror is different, the setting phase and the drawing phase are repeated; and the inspection phase is performed to measure the inspection pattern drawn on the substrate The accuracy of the origin signal is checked by the shape or the deviation of the configuration of the main scanning direction.