Pattern exposure apparatus

Abstract

A pattern exposure apparatus has: a first light splitter that is provided in an optical path of a first light beam between a first light source apparatus and a first drawing unit that draws a pattern on a substrate, and that splits a part of the first light beam into a first measurement light beam; a second light splitter that is provided in an optical path of a second light beam between a second light source apparatus and a second drawing unit that draws a pattern on a substrate, and that splits a part of the second light beam into a second measurement light beam; a variation detection optical unit that receives the first measurement light beam and the second measurement light beam, and that detects a relative positional variation or a relative inclination variation of the first light beam and the second light beam; a first light guide system that forms an optical path based on the first measurement light beam; and a second light guide system that forms an optical path based on the second measurement light beam.

Description

Technical Field

[0001] The present invention relates to a pattern exposure apparatus that uses a pattern beam modulated according to pattern data to expose patterns of electronic devices or the like on a substrate. Background Technology

[0002] Conventionally, in the process of manufacturing micro-electronic devices on a substrate, photolithography is performed. This photolithography process includes: an exposure step, in which an exposure beam (light beam, electron beam, etc.) corresponding to the pattern of the electronic device (a pattern specifying the shape of wiring layers, electrode layers, semiconductor layers, insulating layers, etc.) is irradiated onto a photoresist layer on the substrate; and a development step, in which the exposed substrate is developed to reveal patterns of residual and removed portions of the photoresist layer. As exposure apparatus used in this exposure step, methods using a photomask with a fixed pattern to be exposed are known, and maskless methods that dynamically modulate the intensity of the exposure beam based on drawing data (CAD data) corresponding to the pattern to be exposed.

[0003] Japanese Patent Application Publication No. 2002-196270 discloses a pattern drawing apparatus as a maskless exposure device. This apparatus modulates a laser beam from a laser source using an acousto-optic modulator, causing the modulated beam to be repeatedly deflected one-dimensionally on each reflecting surface of a rotating polygonal mirror. The beam, deflected by the polygonal mirror, is then imaged as a point light on the surface to be scanned via an imaging optical system including an fθ lens, and a one-dimensional scan is performed. Furthermore, Japanese Patent Application Publication No. 2002-196270 also discloses a beam position detector for measuring variations such as the tilt of the beam's travel direction or the lateral deviation of the emitted beam, and an optical component for correcting the shift in the scanning position of the point light caused by these variations.

[0004] In the pattern drawing apparatus described in Japanese Patent Application Publication No. 2002-196270, a beam from a single laser source is supplied to a drawing unit comprising a multifaceted mirror and an fθ lens. However, in multi-drawing head type exposure apparatuses that arrange multiple drawing units in a manner that sequentially exposes a pattern drawn by point-light-based main scan drawing lines (scan lines) in the main scanning direction, multiple laser sources are sometimes used. In this case, in addition to the shift in the exposure position of the pattern caused by the individual variation of the beams emitted from each of the multiple laser sources, it is also necessary to reduce the generation of continuity errors caused by variations in the relative position and tilt of the beams from each of the multiple laser sources. Summary of the Invention

[0005] A first aspect of the present invention is a pattern exposure apparatus comprising: a first drawing unit that draws a pattern on a substrate using a first light beam from a first light source device; and a second drawing unit that draws a pattern on the substrate using a second light beam from a second light source device, wherein the pattern exposure apparatus comprises: a first light splitter disposed in the optical path of the first light beam from the first light source device to the first drawing unit, splitting a portion of the first light beam into a first measuring light beam; and a second light splitter disposed in the optical path of the second light beam from the second light source device to the first drawing unit. In the optical path between the second drawing units, a portion of the second beam is split into a second measuring beam; a variation detection optical unit receives the first measuring beam and the second measuring beam, and detects relative positional changes or relative tilt changes between the first beam and the second beam; a first light guiding system forms an optical path from the first light splitter to the variation detection optical unit based on the first measuring beam; and a second light guiding system forms an optical path from the second light splitter to the variation detection optical unit based on the second measuring beam.

[0006] A second aspect of the present invention is a pattern exposure apparatus comprising: a first light source device that emits a first light beam; a second light source device that emits a second light beam; a plurality of acousto-optic modulation elements that allow the first light beam and the second light beam to pass in series; and a plurality of drawing units that use the diffracted beams of the first light beam and the second light beam generated by the plurality of acousto-optic modulation elements as point lights, and perform one-dimensional scanning of the point lights to draw a pattern on a substrate. Attached Figure Description

[0007] Figure 1 This is a front view showing the general overall structure of the pattern exposure apparatus of the first embodiment.

[0008] Figure 2 It is shown Figure 1 A perspective view of the schematic internal structure of MU1, a representative of the depiction units MU1 to MU6 shown.

[0009] Figure 3 It is shown that on the support Figure 1 A perspective view of the arrangement of the drawing lines SL1 to SL6 set on the sheet substrate P of the rotating cylinder DR and the arrangement of the alignment system ALGn (ALG1 to ALG5).

[0010] Figure 4 It is observed from a plane parallel to the XY plane. Figure 1 A top view of the optical structure within the beam switching unit (BDU).

[0011] Figure 5 It shows from Figure 4 A perspective view showing the arrangement of various optical components near the optical path from the laser source 10B to the initial acoustic modulation optical element (AOM) AM6 for switching.

[0012] Figure 6 It is shown Figure 4 A three-dimensional diagram showing the specific configuration relationship between the triangular mirror 33 and the detection unit 34.

[0013] Figure 7 It schematically shows the projection onto Figure 6 A diagram showing the state of the beams MBa and MBb on the imaging surface of the first imaging element 34C.

[0014] Figure 8 It schematically shows the projection onto Figure 6 The diagram shows the state of the spotlights MBa and MBb on the imaging surface of the second imaging element 34G.

[0015] Figure 9 It is shown Figure 4 , Figure 5 A perspective view of an example of the specific optical structure of the correction optical system 11B shown.

[0016] Figure 10 This is to explain from Figure 5 A three-dimensional view showing the parallel shift of the beam LBb in the optical path from the laser source 10B to the primary acousto-optic modulator AM6.

[0017] Figure 11 This diagram exaggerates the state of the beams LB2, LB4, and LB6 used for depicting the even-numbered depicting units MU2, MU4, and MU6 as the beam LBb from the laser source 10B is parallelly shifted in the -Y direction.

[0018] Figure 12 It is an exaggerated diagram showing the state of the beams LB2, LB4, and LB6 used for depicting the even-numbered depicting units MU2, MU4, and MU6 when the beam LBb from the laser source 10B is parallelly shifted in the +Z direction.

[0019] Figure 13 The diagram exaggerates the state of the beam LBb incident on the primary acousto-optic modulation element AM6 as it tilts toward the beams LB2, LB4, and LB6 used for depicting the even-numbered depicting units MU2, MU4, and MU6, respectively.

[0020] Figure 14 It is an exaggerated depiction of the beam LBb incident on the primary acousto-optic modulator AM6 and its direction relative to... Figure 13The diagram shows the state of the beams LB2, LB4, and LB6 used for depicting even-numbered depicting units MU2, MU4, and MU6 when the direction described in the diagram is tilted vertically.

[0021] Figures 15A-15C This diagram illustrates the incident state and diffraction efficiency of the beam LBb from the laser source 10B incident on the primary acousto-optic modulation element AM6 of the beam switching unit BDU. Figure 15A This is a diagram showing the AM6 acousto-optic modulation element observed in the XZ plane of the vertical coordinate system XYZ. Figure 15B This is a diagram showing the AM6 acousto-optic modulation element observed in the XY plane of the vertical coordinate system XYZ. Figure 15C It is a schematic graph showing the incident angle θz of the diffraction direction of the beam LBb incident on the acousto-optic modulation element AM6 and the change of the intensity of the beam LB6 (the first-order diffracted beam) relative to the incident angle θy of the non-diffraction direction.

[0022] Figure 16 This is a perspective view showing the state of the two beams in the optical path from the primary acousto-optic modulation element AM6 to the incident mirror IM6 of the beam switching unit BDU in the second embodiment.

[0023] Figure 17 It is an exaggerated depiction of passing through from Figure 16 The diagram shows the state of the two beams LB6a and LB6b of the light path of the incident mirror IM6 reaching the lens LGA in the drawing unit MU6 through the light path adjustment unit BV6.

[0024] Figure 18 This is a diagram illustrating an example of an optical path that guides the light beams from the four laser sources 10A1, 10A2, 10B1, and 10B2 used in the second embodiment to the primary acousto-optic modulation elements AM6 and AM1.

[0025] Figure 19 It is shown schematically in Figures 16-18 The diagram shown illustrates the scanning of two point lights SPa and SPb projected onto the sheet substrate P in the second embodiment.

[0026] Figure 20 It is shown Figure 2 A perspective view of a modified example of the depiction unit MU1 (and MU2 to MU6 as well).

[0027] Figure 21 It is shown Figure 17 A perspective view of a modified example of a portion of the optical path adjustment unit BV6 shown.

[0028] Figure 22This is a schematic diagram illustrating a variation of the optical path of the four measuring beams when using four laser light sources.

[0029] Figure 23 It is shown Figure 22 A perspective view showing the configuration relationship of the variable optical detection system (triangular mirror 33' and detection unit 34) in the case of a modified example. Detailed Implementation

[0030] Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these embodiments and includes various modifications or alterations. That is, the structural elements described below include elements readily conceived by those skilled in the art, substantially the same elements, and the structural elements described below can be appropriately combined. Furthermore, various omissions, substitutions, or changes to structural elements can be made without departing from the spirit of the present invention.

[0031] [First Implementation]

[0032] Figure 1 This is a diagram showing the general overall structure of the pattern exposure apparatus according to the first embodiment. Figure 1 As shown, the pattern exposure apparatus of this embodiment exposes various patterns corresponding to electronic devices (display devices, wiring devices, sensor devices, etc.) in a maskless manner by scanning a photosensitive layer coated on a flexible, elongated sheet substrate P (hereinafter also simply referred to as substrate P). Such pattern exposure apparatuses are disclosed, for example, in International Publication Nos. 2015 / 152218, 2015 / 166910, 2016 / 152758, and 2017 / 057415.

[0033] like Figure 1 As shown, the pattern exposure apparatus EX of this embodiment is installed on the ground in a location (such as a factory) parallel to the XY plane of a vertical coordinate system XYZ with the direction of gravity as the Z-axis. The exposure apparatus EX includes: a rotating cylinder DR for stably supporting a sheet substrate P and transporting it at a constant speed; six drawing units MU1 to MU6 for drawing patterns on the photosensitive layer of the sheet substrate P; a beam switching unit BDU for time-division switching and distributing the beams LBa and LBb from two laser light sources 10A and 10B to each of the drawing units MU1 to MU6; optical path adjustment units BV1 to BV6 for causing the beams LB1, LB2, ... distributed by the beam switching unit BDU to be incident on each of the drawing units MU1 to MU6 at an adjusted angle; and multiple alignment systems ALGn (where n = 1 to 5) for detecting alignment marks on the sheet substrate P via an objective lens system OBL.

[0034] The rotating cylinder DR has: a cylindrical outer peripheral surface with a certain radius extending from the rotation center line AXo, which is parallel to the Y-axis of the XY plane; and a shaft Sft, which protrudes coaxially with the rotation center line AXo towards both ends of the rotating cylinder DR in the Y direction. A sheet substrate P is tightly supported along the outer peripheral surface of approximately half a circumference of the rotating cylinder DR in the longitudinal direction, and is conveyed at a constant speed in the longitudinal direction by the constant speed rotation of the rotating cylinder DR caused by the rotational torque from a rotational drive motor (not shown). It should be noted that the substrate P is made of resin materials such as PET (polyethylene terephthalate) film, PEN (polyethylene naphthalate) film, and polyimide film. Alternatively, it can be, for example, an extremely thin sheet of flexible glass material with a thickness of less than 100 μm, a thin sheet of metal material such as stainless steel formed by rolling, or paper containing cellulose nanofibers.

[0035] Multiple drawing units MU1 to MU6 are arranged in the space above the rotating cylinder DR along the Y direction. However, each of the odd-numbered drawing units MU1, MU3, and MU5, and each of the even-numbered drawing units MU2, MU4, and MU6, are arranged symmetrically with respect to the center plane Cp, which is parallel to the YZ plane and contains the rotation center line AXo, when viewed in the XZ plane. The odd-numbered drawing units MU1, MU3, and MU5 are mounted on the column frame BF of the device body with the extension of the center line of the beam LB1 (LB3, LB5) projected onto the sheet substrate P facing the rotation center line AXo, and tilted at an angle -θu from the center plane Cp when viewed in the XZ plane. Similarly, the even-numbered drawing units MU2, MU4, and MU6 are mounted on the column frame BF of the device body with the extension of the center line of the beam LB2 (LB4, LB6) projected onto the sheet substrate P facing the rotation center line AXo, and tilted at an angle +θu from the center plane Cp when viewed in the XZ plane.

[0036] Figure 1The mounting structure of each of the depicting units MU1 to MU6 toward the column frame BF is disclosed, for example, in International Publication No. 2016 / 152758. The odd-numbered depicting units MU1, MU3, and MU5 are each configured to rotate within a small angular range (e.g., ± a few degrees or less) around the rotation axis LE1 (LE3, LE5), and the even-numbered depicting units MU2, MU4, and MU6 are each configured to rotate within a small angular range (e.g., ± a few degrees or less) around the rotation axis LE2 (LE4, LE6). The extension lines of each rotation axis LE1 (LE3, LE5) and LE2 (LE4, LE6) are arranged perpendicular to the rotation center line AXo, and are positioned at the midpoint of the Y-direction of the depicting line formed by the point light on the sheet substrate P formed by the scanning of the beams LB1 to LB6 from each of the depicting units MU1 to MU6.

[0037] The internal structures of each of the drawing units MU1 to MU6, as disclosed in International Publication No. 2016 / 152758 or International Publication No. 2019 / 082850, include multiple mirrors, multiple lenses, a rotating polyhedron PM, and a telecentric fθ lens system FT. The centerlines of the light beams LB1 to LB6 emitted from each of the optical path adjustment units BV1 to BV6 and incident on the corresponding drawing units MU1 to MU6 are set to be coaxial with the rotation axes LE1 to LE6, respectively. Furthermore, within the drawing units MU1 to MU6, a vertical coordinate system XtYtZt is defined by the Zt axis, which is parallel to the rotation axes LE1, LE2, etc., and the Xt and Yt axes, which are perpendicular to the Zt axis. Therefore, the Yt axis of the vertical coordinate system XtYtZt is parallel to the Y axis of the vertical coordinate system XYZ, and the vertical coordinate system XtYtZt is tilted about the Y axis by an angle θu (angle - θu or angle + θu) relative to the XY plane of the vertical coordinate system XYZ.

[0038] From Figure 1The laser beam LBa from the laser source 10A is sequentially and time-divisionally distributed to any one of the odd-numbered drawing units MU1, MU3, and MU5 within the beam switching unit BDU. The laser beam LBb from the laser source 10B is sequentially and time-divisionally and repeatedly distributed to any one of the even-numbered drawing units MU2, MU4, and MU6 within the beam switching unit BDU. Within the beam switching unit BDU, as disclosed in International Publication No. 2016 / 152758, beam switching is performed using an acousto-optic modulation element (AOM). In this embodiment, the relative variation (lateral shift error, tilt error) between the laser beam LBa from the laser source 10A and the laser beam LBb from the laser source 10B is measured within the beam switching unit BDU, details of which will be described later. Furthermore, the acousto-optic modulation element (AOM) and various optical components (mirrors, lenses, etc.) constituting the laser sources 10A and 10B and the beam switching unit BDU are mounted on an optical platform OBP.

[0039] Figure 2 It is shown Figure 1 A perspective view of the schematic internal structure of MU1, a representative of the depiction units MU1 to MU6 shown. Figure 2 The structure of the depiction unit MU1 is substantially the same as that disclosed in International Publication No. 2016 / 152758, and therefore will be described simply. The beam LB1 (a parallel beam with a diameter of 1 mm or less) from the optical path adjustment unit BV1 is coaxially incident on the reflector M10 along with the rotation axis LE1 extending parallel to the Zt axis. After being reflected 90 degrees, it passes through a beam expander based on lenses LGa and LGb, and is then reflected 90 degrees by the reflector M11 before being incident on the polarization beam splitter PBS. The beam LB1 is linearly polarized light (S-polarized light) along the Zt axis, and is therefore efficiently reflected by the polarization beam splitter PBS. It is reflected 90 degrees by the reflector M12 and propagates in the -Zt direction, and is reflected 90 degrees by the reflector M13 and propagates in the +Xt direction. The beam LB1, reflected by mirror M13, passes through the 1 / 4 wavelength (λ / 4) plate QP and the first cylindrical lens CYa, and is then reflected by mirror M14, reaching one of the reflecting surfaces Rp1 of the rotating polygonal mirror PM.

[0040] The light beam LB1, reflected by the reflecting surface Rp1 of the rotating polygon mirror PM, is deflected within the XtYt plane by the rotation of the rotating polygon mirror PM and incident on the telecentric fθ lens system FT, which has an optical axis AXf1 parallel to the Xt axis. Immediately following the fθ lens system FT, a reflecting mirror M15 is positioned that bends the optical axis AXf1 by 90 degrees. The light beam LB1 emitted from the fθ lens system FT is reflected by the reflecting mirror M15 at a 90-degree angle parallel to the Zt axis. A second cylindrical lens CYb is positioned between the reflecting mirror M15 and the sheet substrate P. The light beam LB1 emitted from the fθ lens system FT is focused as a point beam SP on the sheet substrate P, and this point beam SP is scanned one-dimensionally by the rotation of the rotating polygon mirror PM to form a drawing line (scanning line) SL1 parallel to the Yt axis (Y-axis).

[0041] exist Figure 2 In the depiction unit MU1 shown, a lens system LGc and a photoelectric sensor DT, positioned opposite the reflector M12 and separated by a polarizing beam splitter PBS, receive reflected light generated from the sheet substrate P by the projection of a point light SP. By analyzing the waveform of the photoelectric signal from the photoelectric sensor DT, the positional information of the pattern formed on the sheet substrate P can be obtained. Furthermore, in Figure 2 In this system, surface OPa is the rear focal point of lens LGa and is set at the front focal point of lens LGb. Beam LB1 is focused at surface OPa onto a beam waist with a diameter of tens of μm. Therefore, beam LB1 passing through lens LGb becomes a parallel beam with a diameter magnified to several mm or more. Furthermore, the first cylindrical lens CYa, the second cylindrical lens CYb, and the fθ lens system FT cooperate to correct for positional variations in the Xt direction of the point light SP (drawing line SL1) caused by differences in the tilt of each reflecting surface of the rotating polygon mirror PM.

[0042] Figure 3 This is a perspective view showing the arrangement of the tracing lines SL1 to SL6 on the sheet-like substrate P supported by the rotating cylinder DR, and the arrangement of the alignment system ALGn (ALG1 to ALG5). Figure 3 In the rotating cylinder DR, a scale disk RSD of the encoder measurement system is fixed coaxially with the rotation center line AXo on the shaft Sft at both ends. Scale sections SD1 and SD2, with grid lines etched at regular intervals along the circumference, are formed on the outer circumferential surface of the scale disk RSD. Changes in the circumferential position of the scale sections SD1 and SD2 are measured with sub-micron resolution by encoder heads EH1, EH2, and EH3, respectively located at three circumferential positions. Furthermore, a belt-shaped reference surface Rst is formed on the side end portion of the scale disk RSD parallel to the XZ plane. The minute displacement of this reference surface Rst in the Y direction is measured with sub-micron resolution by displacement sensors YS1, YS2, and YS3, respectively located at three circumferential positions.

[0043] Of the drawing lines SL1 to SL6 formed on the sheet substrate P by each of the drawing units MU1 to MU6, the odd-numbered drawing lines SL1, SL3, and SL5 located upstream of the sheet substrate P in the transport direction are arranged parallel to the rotation center line AXo (Y-axis) and spaced apart in the Y-direction by a certain interval (approximately the length of the drawing line). Similarly, the even-numbered drawing lines SL2, SL4, and SL6 located downstream of the sheet substrate P in the transport direction are arranged parallel to the rotation center line AXo (Y-axis) and spaced apart in the Y-direction by a certain interval (approximately the length of the drawing line). The patterns drawn by the drawing lines SL1 to SL6 are exposed in a manner that they interlock as the sheet substrate P is transported.

[0044] In the transport direction of the sheet substrate P, upstream of the odd-numbered drawing lines SL1, SL3, and SL5, five alignment systems ALG1 to ALG5 are arranged at predetermined intervals in the Y direction as alignment systems ALGn. Alignment system ALG1 detects alignment marks formed near the end of the sheet substrate P in the -Y direction direction via the objective lens system OBL and the front-end mirror MR. Alignment system ALG5 detects alignment marks formed near the end of the sheet substrate P in the +Y direction direction via the same objective lens system OBL and the front-end mirror MR. The detection areas (detection fields) of each alignment system ALG1 to ALG5 are arranged in a row in the Y direction, and the circumferential orientation of this detection area as observed from the rotation center line AXo is set to coincide with the circumferential orientation of the encoder head EH3's reading position as observed from the rotation center line AXo.

[0045] Furthermore, the circumferential orientation of the odd-numbered drawing lines SL1, SL3, and SL5 as observed from the rotation center line AXo is set to be consistent with the circumferential orientation of the encoder head EH1's reading position as observed from the rotation center line AXo, and the circumferential orientation of the even-numbered drawing lines SL2, SL4, and SL6 as observed from the rotation center line AXo is set to be consistent with the circumferential orientation of the encoder head EH2's reading position as observed from the rotation center line AXo. Additionally, as previously... Figure 2 As shown, the optical axis AXf1 of the fθ lens system FT of the drawing unit MU1 is bent by the reflector M15 and set to be perpendicular to the tangential plane that contacts the surface of the sheet substrate P at the position of the drawing line SL1. Therefore, the extension of the optical axis AXf1 is directed toward the rotation center line AXo, and the intersection of the optical axis AXf1 and the sheet substrate P is the midpoint of the length of the drawing line SL1 in the Y direction (main scanning direction).

[0046] Next, refer to Figure 4 , Figure 5 ,illustrate Figure 1The schematic structure of the beam switching unit BDU is shown. In this embodiment, a function (mechanism) for measuring the variation of the emitted beams LBa and LBb from the two laser sources 10A and 10B is provided in the beam switching unit BDU. Figure 4 This is a top view of the structure inside the beam switching unit (BDU) observed in a plane parallel to the XY plane. Figure 5 It shows from Figure 4 A perspective view of the configuration of optical components near the optical path from the laser source 10B to the initial acoustic modulation optical element (AOM) AM6 used for switching. Includes... Figure 4 All optical components of the laser light sources 10A and 10B are assembled in Figure 1 The optical platform OBP shown is used. Laser sources 10A and 10B are, for example, fiber amplifier laser sources described in International Publication Nos. 2015 / 166910 and 2018 / 164087. Therefore, in this embodiment, intensity modulation based on the drawing data of beams LB1 to LB6 projected from each drawing unit MU1 to MU6 onto the sheet substrate P is also performed by high-speed switching of the various infrared wavelength regions of the laser sources 10A and 10B using electro-optic elements (EO elements) that respond to clock signals of 100 MHz or higher, such as 400 MHz.

[0047] The optical paths of the beams LBa and LBb from laser sources 10A and 10B, respectively, will be described below. However, for ease of explanation, the optical path of the beam LBb from laser source 10B will be described first. The beam LBb from laser source 10B has a wavelength in the ultraviolet wavelength region (e.g., wavelength below 400 nm) that sensitizes the photosensitive layer on the sheet substrate P, and is emitted in the -X direction as a parallel beam with a diameter of about 1 mm. The beam LBb from laser source 10B is incident on beam splitter 30B, which has high transmittance and low reflectivity of about a few percent to 10%. The beam LBb passing through here is guided to the even-numbered drawing units MU2, MU4, and MU6. The beam MBb reflected by beam splitter 30B is used for measuring beam variation via mirror 31B, lens GL1b, mirror 32B, and lens GL2b, as detailed later.

[0048] The beam LBb, having passed through beam splitter 30B, is then incident on beam splitter 12B, which has a transmittance of less than a few percent, after being finely adjusted by the tilting of the beam LBb's travel direction or slightly laterally shifted in a plane perpendicular to the beam by the correction optical system 11B. The beam passing through beam splitter 12B is received by light quantity monitor 13B, which measures the intensity of the beam LBb from laser source 10B. The beam LBb, reflected in the -Y direction by beam splitter 12B, is converted into a parallel beam with a beam diameter reduced to approximately 0.5 mm by the reduction relay optical system 14B. This parallel beam is then converted by mirror system 15B into a light path traveling in the +X direction and incident on the primary switching acousto-optic modulation element AM6.

[0049] When the acousto-optic modulator AM6 is in the off state (non-deflection state), the beam LBb passes directly through the acousto-optic modulator AM6, and then through the condenser lens 16B, collimating lens 17B, and reflector 18B, and is incident as a parallel beam onto the second-order switching acousto-optic modulator AM4. In the XY plane, a reflector IM6 with a reflective surface tilted at 45 degrees relative to the XY plane is positioned at the rear focal point of the condenser lens 16B. This reflector IM6 is configured to reflect only the first-order diffracted beam generated when the acousto-optic modulator AM6 is in the on state (deflection state) in the -Z direction, without illuminating the undiffracted 0th-order beam (a portion of the beam LBb).

[0050] Here, refer to Figure 5 This provides a more detailed explanation of the optical path from the laser source 10B to the reflector IM6. For example... Figure 5 As shown, the laser beam LBb emitted from the laser source 10B, passing through the correction optical system 11B and the reduction relay optical system 14B, is reflected in the -Z direction by the reflector 15B1 constituting the reflector system 15B, and then reflected in the +X direction by the reflector 15B2. If the beam LBb reflected by the reflector 15B2 is incident on the acousto-optic modulation element AM6 in the on state, a beam LB6, which is a first-order diffracted beam deflected in the -Z direction at a certain diffraction angle, is generated from the acousto-optic modulation element AM6. The acousto-optic modulation element AM6 is arranged at the front focal point of the condenser lens 16B in a manner that satisfies the conditions of Bragg diffraction, and is arranged so that the beam LBb (or the 0th-order beam) that directly passes through the acousto-optic modulation element AM6 passes simultaneously with the optical axis of the condenser lens 16B. According to this structure, the beam LB6, which is a first-order diffracted beam, passing through the condenser lens 16B, is parallel to the optical axis of the condenser lens 16B, reaches the incident mirror IM6 at a position deflected from the optical axis in the -Z direction, and is reflected in the -Z direction.

[0051] Furthermore, the incident beam LBb (or 0th order beam) before the condenser lens 16B and the beam LB6, which is a 1st order diffracted beam, are both parallel beams with a diameter of approximately 0.5 mm. However, at the rear focal point of the condenser lens 16B, they both become beam waists with a diameter of approximately 0.1 to 0.2 mm, located at a split position in the Z direction. Therefore, the incident mirror IM6 can reflect the beam LB6 only in the -Z direction. Additionally, the two lenses GL1b and GL2b through which the measurement beam MBb reflected by the beam splitter 30B passes constitute an equal-magnification relay imaging system, such as... Figure 4 As shown, a surface Psb optically conjugate to the emission outlet of the laser beam LBb from the laser source 10B is formed at the rear focal point of lens GL2b. Furthermore, a light guiding system is constructed from mirrors 31B and 32B, lenses GL1b and GL2b, which guides the measurement beam MBb to the variation detection optical unit composed of a triangular mirror 33 and a detection unit 34.

[0052] In this embodiment, the light guiding system is configured as reflectors 31B and 32B, lenses GL1b and GL2b, but the change detection optical unit can also be configured as a detection unit 34, which includes a beam splitter 30B, reflectors 31B and 32B, lenses GL1b and GL2b, and the reflective surface of one of the triangular mirrors 33, and is configured as a light guiding system.

[0053] Return again Figure 4 Continuing the explanation, the position of the rear focal point of the condenser lens 16B is set to coincide with the position of the front focal point of the collimating lens 17B in the subsequent stage. The optical axis of the condenser lens 16B is coaxially arranged with the optical axis of the collimating lens 17B. The beam LBb (or the 0th order beam) passing through the condenser lens 16B is converted again by the collimating lens 17B into a parallel beam with a diameter of approximately 0.5 mm, reflected by the reflector 18B, and incident on the second-order acousto-optic modulator AM4, which is configured under Bragg diffraction conditions. The beam LBb incident on the acousto-optic modulator AM4 is reflected in the -X direction by the reflector 19B, and then, via the condenser lens 20B (configured in the same way as the condenser lens 16B), the collimating lens 21B (configured in the same way as the collimating lens 17B), and the reflector 22B, incident on the third-order acousto-optic modulator AM2, which is configured under Bragg diffraction conditions. Here, the position of the rear focal point of the condenser lens 20B and the position of the front focal point of the collimating lens 21B are also set to coincide. Furthermore, at the rear focal point of the condenser lens 20B, there is an epipolar mirror IM4, which is the same as the epipolar mirror IM6. Only when the acousto-optic modulation element AM4 is turned on, the beam LB4, which is a first-order diffraction beam, is reflected in the -Z direction by the epipolar mirror IM4.

[0054] The beam LBb, which passes through the third-order acousto-optic modulator AM2, is reflected in the +X direction by mirror 23B and then enters beam splitter 26B through condenser lens 24B and collimating lens 25B. Beam splitter 26B has a high transmittance and a low reflectance setting, and the beam LBb (or the 0th-order diffracted beam) passing through beam splitter 26B is absorbed by beam trap 27B. A portion of the beam reflected by beam splitter 26B is received by photodetector 28B, which measures the intensity and position of the beam LBb (or the 0th-order diffracted beam) passing through the three acousto-optic modulators AM6, AM4, and AM2. At the beam waist position (the rear focal point of condenser lens 24B) of beam LBb between condenser lens 24B and collimating lens 25B, a mirror IM2, identical to mirrors IM6 and IM4, is positioned. Only when acousto-optic modulator AM2 is in the on state, the beam LB2, which is a 1st-order diffracted beam, is reflected in the -Z direction by mirror IM2.

[0055] When observed in the XY plane, the incident mirrors IM6, IM4, and IM2 are respectively aligned with the reflectors M10 of the even-numbered depiction units MU6, MU4, and MU2 (refer to...). Figure 2 The configuration is consistent in the XY plane. Therefore, as... Figure 4 As shown, the reflector mirrors IM6, IM4, and IM2 are respectively arranged at certain intervals on line Kb parallel to the Y-axis in the XY plane, and are positioned at the same location in the Z direction. Furthermore, the laser source 10A is identical to the laser source 10B, and the optical path configuration (arrangement of each optical component) of the beam LBa from the laser source 10A in the XY plane is such that the optical path configuration (arrangement of each optical component) of the beam LBb from the laser source 10B is rotated 180 degrees in the XY plane.

[0056] A beam LBa (e.g., pulsed light with a wavelength below 400 nm) from laser source 10A is emitted as a parallel beam with a diameter of approximately 1 mm in the +X direction. The beam LBa from laser source 10A is incident on beam splitter 30A, which has high transmittance and low reflectance (around a few percent to 10%). The beam LBa passing through this beam is guided to odd-numbered drawing units MU1, MU3, and MU5. The beam MBa reflected by beam splitter 30A is used for beam variation measurement via mirror 31A, lens GL1a, mirror 32A, and lens GL2a. The beam LBa passing through beam splitter 30A is then incident on beam splitter 12A, which has a transmittance of less than a few percent, after being finely adjusted by the tilt of the beam LBa's travel direction or slightly laterally shifted in a plane perpendicular to the beam by a correction optical system 11A. The beam LBa passing through beam splitter 12A is received by a light quantity monitor 13A, which measures the intensity of the beam LBa from laser source 10A.

[0057] The beam LBa, reflected in the +Y direction by beam splitter 12A, is converted into a parallel beam with a diameter reduced to approximately 0.5 mm by reducing optical system 14A, and then reflected by mirror system 15A (and... Figure 5 Similarly, the mirror system 15B shown includes mirrors 15A1 and 15A2, which convert the light path to travel in the -X direction, and incident as a parallel beam onto the primary switching acousto-optic modulator AM1, which is configured under Bragg diffraction conditions. When the acousto-optic modulator AM1 is in the off state (non-deflection state), the beam LBa passes directly through the acousto-optic modulator AM1, and through the condenser lens 16A, collimating lens 17A, and mirror 18A, and is incident as a parallel beam onto the second-order switching acousto-optic modulator AM3, which is configured under Bragg diffraction conditions. In the XY plane, a reflecting mirror IM1 with its reflective surface tilted at 45 degrees relative to the XY plane is arranged at the rear focal point of the condenser lens 16A. This reflecting mirror IM1 is configured to reflect only the first-order diffracted beam generated when the acousto-optic modulator AM1 is in the on state (deflection state) in the -Z direction, and does not illuminate the undiffracted 0th-order beam (a portion of the beam LBb).

[0058] The position of the rear focal point of the condenser lens 16A is set to coincide with the position of the front focal point of the collimating lens 17A in the subsequent stage. The optical axis of the condenser lens 16A is coaxially arranged with the optical axis of the collimating lens 17A. The light beam LBa (or the 0th order beam) passing through the condenser lens 16A is converted again by the collimating lens 17A into a parallel beam with a diameter of about 0.5mm, which is reflected by the reflector 18A and incident on the second-stage acousto-optic modulator AM3. The light beam LBa incident on the acousto-optic modulator AM3 is reflected in the +X direction by the reflector 19A, and then passes through the condenser lens 20A, which is arranged in the same manner as the condenser lens 16A, the collimating lens 21A, which is arranged in the same manner as the collimating lens 17A, and the reflector 22A, and is incident on the third-stage acousto-optic modulator AM5, which is arranged under Bragg diffraction conditions.

[0059] Here, the position of the rear focal point of the condenser lens 20A and the position of the front focal point of the collimating lens 21A are also set to be the same. Moreover, at the position of the rear focal point of the condenser lens 20A, there is an epipolar mirror IM3 that is the same as the epipolar mirror IM1. The beam LB3, which is a first-order diffracted beam generated only when the acousto-optic modulation element AM3 is turned on, is reflected in the -Z direction by the epipolar mirror IM3.

[0060] The light beam LBa, which has passed through the third-order acousto-optic modulator AM5, is reflected in the -X direction by mirror 23A and then incident on beam splitter 26A through condenser lens 24A and collimating lens 25A. Beam splitter 26A is configured to have high transmittance and low reflectance, and the light beam LBa (or the 0th-order diffracted beam) passing through beam splitter 26A is absorbed by beam trap 27A. A portion of the light beam reflected by beam splitter 26A is received by photodetector 28A to measure the intensity and position of the light beam LBa (or the 0th-order diffracted beam) that has passed through the three acousto-optic modulators AM1, AM3, and AM5.

[0061] At the beam waist position (the position of the rear focal point of the condenser lens 24A) of the beam LBa between the condenser lens 24A and the collimating lens 25A, an incident mirror IM5, identical to that of incident mirrors IM1 and IM3, is positioned. Only when the acousto-optic modulation element AM5 is in the on state, the beam LB5, which is a first-order diffracted beam, is reflected in the -Z direction by incident mirror IM5. Furthermore, when observed in the XY plane, incident mirrors IM1, IM3, and IM5 are respectively aligned with the reflecting mirrors M10 of the odd-numbered depiction units MU1, MU3, and MU5 (see reference). Figure 2 The configuration is consistent in the XY plane. Therefore, as... Figure 4 As shown, the incident mirrors IM1, IM3, and IM5 are respectively arranged at certain intervals on line Ka parallel to the Y-axis in the XY plane, and are positioned at the same location in the Z direction.

[0062] The acousto-optic modulation elements AM1 to AM6 used for switching are all arranged to satisfy the conditions of Bragg diffraction. In addition, two lenses GL1a and GL2a, through which the measurement beam MBa reflected by the beam splitter 30A passes, constitute an equal-magnification relay imaging system, such as... Figure 4 As shown, a surface Psa, optically conjugate to the exit point of the laser beam LBa from the laser source 10A, is formed at the rear focal point of lens GL2a. Furthermore, a light guiding system, consisting of mirrors 31A and 32A, lenses GL1a and GL2a, guides the measurement beam MBa to the variation detection optical unit comprised of the triangular mirror 33 and the detection unit 34. In this embodiment, the optical path length and the optical path reversal position of the measurement beam MBa from the exit point of the laser source 10A to the triangular mirror 33 (and the detection unit 34) are set to be the same as the optical path length and the optical path reversal position of the measurement beam MBb from the exit point of the laser source 10B to the triangular mirror 33 (and the detection unit 34).

[0063] In the above structure, the emission outlet of laser source 10A, via correction optical system 11A and reduction optical system 14A, is optically conjugate with the crystal within the primary acousto-optic modulation element AM1. Similarly, the emission outlet of laser source 10B, via correction optical system 11B and reduction relay optical system 14B, is optically conjugate with the crystal within the primary acousto-optic modulation element AM6. Furthermore, Figure 4 The positions of the reflecting surfaces of the incident mirrors IM1 to IM6 are set to be the same as the surfaces OPa set inside the drawing units MU1 to MU6 (see reference). Figure 2 The optical conjugate relationship is established. As a result, the positions of the reflecting surfaces of the incident mirrors IM1 to IM6 (with beams LB1 to LB6 serving as the beam waists and focusing positions) and the imaging surface of the point light SP focused on the sheet substrate P are set to be optically conjugate.

[0064] The optical path configuration in the XY plane from laser source 10A to beam trap 27A and photodetector 28A is rotated 180 degrees relative to the optical path configuration in the XY plane from laser source 10B to beam trap 27B and photodetector 28B, but its hypothetical rotation center point (center point of point symmetry) PG is set at... Figure 4 The midpoint of line Ka and line Kb in the X direction, and the midpoint of the Y direction of the incident mirror IM1 (located on the -Y side) and the midpoint of the Y direction of the incident mirror IM6 (located on the +Y side). Therefore, in the XY plane, the imaginary line segment connecting incident mirrors IM1 and IM6, the imaginary line segment connecting incident mirrors IM2 and IM5, and the imaginary line segment connecting incident mirrors IM3 and IM4 are set to intersect at the point-symmetric center point PG. The midpoint of line Ka and line Kb in the X direction and Figure 1 , Figure 3 Since the position of the central plane Cp shown is consistent, the center point PG is located inside the central plane Cp.

[0065] like Figure 5 As shown, the optical axes of the beam LBb emitted from the laser source 10B and the beam LBb passing through the primary acousto-optic modulation element AM6 are set to have a predetermined interval (height difference) in the Z direction through the two mirrors of the mirror system 15B. Therefore, the beam MBb reflected by the beam splitter 30B located directly behind the laser source 10B travels in the -Y direction above the +Z direction of the acousto-optic modulation elements AM1 to AM6, is reflected 90 degrees in the +X direction by mirror 31B, and then reflected 90 degrees in the -Y direction by mirror 32B. Figure 4As shown, the optical axes of the beam LBa emitted from the laser source 10A and the beam LBa passing through the primary acousto-optic modulation element AM1 are set to have a predetermined interval (height difference) in the Z direction through the two mirrors of the mirror system 15A. Therefore, the beam MBa reflected by the beam splitter 30A located directly behind the laser source 10A propagates in the +Y direction above the +Z direction of the acousto-optic modulation elements AM1 to AM6, is reflected 90 degrees in the -X direction by mirror 31A, and then reflected 90 degrees in the +Y direction by mirror 32A.

[0066] Furthermore, the centerline (optical axis of lenses GL1b and GL2b) of the measurement beam MBb reflected by mirror 32B and the centerline (optical axis of lenses GL1a and GL2a) of the measurement beam MBa reflected by mirror 32A are set to be parallel and coaxial with the Y-axis, and are set to intersect the normal of the XY plane passing through the center point PG. Moreover, a triangular mirror 33 is arranged at the center point PG to reflect beams MBa and MBb in the +X direction, respectively. The beams MBa and MBb (both parallel beams) reflected by the triangular mirror 33 and advancing in the +X direction are incident on the detection unit 34 for monitoring beam changes. Furthermore, the triangular mirror 33 and the detection unit 34 constitute a change detection optical unit. Additionally, the optical path length from the emission outlet of the laser source 10A to the beam splitter 30A and the optical path length from the emission outlet of the laser source 10B to the beam splitter 30B are set to be the same.

[0067] Figure 6 It is shown Figure 4 A three-dimensional diagram showing the specific configuration relationship between the triangular mirror 33 and the detection unit 34. Figure 6 The vertical coordinate system XYZ is set to be the same as the vertical coordinate system XYZ. Figure 4 The vertical coordinate system XYZ is the same. Figure 6 In the triangle 33, there are two reflective surfaces: a reflective surface 33a that reflects a beam MBa traveling in the +Y direction at a right angle to the +X direction, and a reflective surface 33b that reflects a beam MBb traveling in the -Y direction at a right angle to the +X direction. The reflective surfaces 33a and 33b are set at a right angle (90 degrees) in the XY plane. The normal line passing through the center point PG and parallel to the Z-axis is set to be perpendicular to the extension of the center lines of the beams MBa and MBb before reaching the triangle 33.

[0068] The detection unit 34 includes: a telecentric reduction relay optical system (detection lens system, imaging system) consisting of a pair of lenses 34A and 34B arranged along the optical axis AXu; a 2D imaging element (CCD sensor or CMOS sensor) 34C; a beam splitter (semi-transparent mirror) 34E; and a second imaging element (CCD sensor or CMOS sensor) 34G. The optical axis AXu is set to be parallel to the X-axis, and its extension is set to be perpendicular to the normal line passing through the center point PG and parallel to the Z-axis. The pair of lenses 34A and 34B (detection lens system, imaging system) reduce the distance between two beams MBa and MBb incident on lens 34A parallel to the optical axis AXu in the YZ plane and their respective beam diameters at a predetermined reduction ratio, and project them onto the imaging surface of the first imaging element 34C. Here, the position of the front focal point of lens 34A is set to be parallel to the optical axis AXu. Figure 4 The planes Psa and Psb shown are consistent. Therefore, the imaging plane of the imaging element 34C is set to be conjugate (imaging relationship) with the emission outlets of the laser source 10A and the laser source 10B, respectively.

[0069] Between a pair of lenses 34A and 34B, two incident light beams MBa and MBb (parallel beams) converge as beam waists and intersect at a condenser surface Ph. The condenser surface Ph is located at the rear focal point of lens 34A and is also located at the front focal point of lens 34B (the pupil plane of the imaging system based on lenses 34A and 34B). The reflective surface of a beam splitter (semi-transparent mirror) 34E, positioned between lens 34A and condenser surface Ph, is set at 45° relative to the XY plane, causing a portion of the light beams MBa and MBb transmitted through lens 34A to be reflected in the -Z direction. A portion of the light beams MBa and MBb reflected by the beam splitter (semi-transparent mirror) 34E is focused as a point beam onto approximately the same position on the imaging surface of the second imaging element 34G, located at the rear focal point of lens 34A (i.e., the position corresponding to condenser surface Ph). Furthermore, although in Figure 6 The illustration is omitted, but if the illuminance of the measuring beams MBa and MBb is relatively high relative to the shooting sensitivity of the shooting elements 34C and 34G, an ND filter can be configured in the optical path from the triangular mirror 33 to the beam splitter (semi-transparent mirror) 34E.

[0070] exist Figure 6In the structure of the detection unit 34, for example, when the beam MBa projected onto the reflecting surface 33a of the triangular mirror 33 is shifted parallel to the +X direction by ΔXa from a predetermined position (designed position), the beam MBa incident on the lens 34A is shifted parallel to the +Y direction by the same amount of ΔYa as ΔXa. In this case, the position of the beam waist of the beam MBa formed on the condenser surface Ph does not change from the position of the optical axis AXu within the condenser surface Ph. Therefore, the position of the spot light of the beam MBa condensed on the imaging surface of the second imaging element 34G does not change. Similarly, when the beam MBa incident on the lens 34A is shifted parallel to the +Y direction by ΔYa, the centerline of the beam MBa passing through the center on the condenser surface Ph (the position through which the optical axis AXu passes) tilts in the XY plane from the predetermined state (designed state). Therefore, if the reduction magnification of the reduction relay optical system based on lenses 34A and 34B is set to β, the position of the beam MBa imaged on the imaging surface of the first imaging element 34C will be shifted by β·ΔYa (=β·ΔXa) in the -Y direction from the predetermined position (designed position).

[0071] Furthermore, if the beam MBa projected onto the reflecting surface 33a of the triangular mirror 33 is tilted by Δθa in the XY plane from a predetermined state (designed state), the beam MBa incident on the lens 34A is also tilted by Δθa in the XY plane from a predetermined state (parallel to the optical axis AXu). This slope Δθa corresponds to the slope of the beam LBa at the emission outlet of the laser source 10A. In this case, the position of the beam waist of the beam MBa formed on the focusing surface Ph changes by ΔYθa in the Y direction from the position of the optical axis AXu within the focusing surface Ph, and the position of the point beam MBa imaged on the imaging surface of the second imaging element 34G shifts in the Y direction from the predetermined position (the position through which the optical axis AXu passes) by an amount corresponding to the magnitude of the tilt ΔYθa.

[0072] On the other hand, the result of the reduced relay optical system based on lenses 34A and 34B is that the surface Psa (refer to) is conjugate to the exit point of the beam LBa of the laser source 10A. Figure 4 The imaging surfaces of the first imaging element 34C and the second imaging element 34G are in an imaging relationship. Therefore, even if only the tilt of the beam LBa changes at the exit position of the laser source 10A, the position of the beam MBa imaged on the imaging surface of the first imaging element 34C remains unchanged. As described above, the first imaging element 34C can detect the component of parallel position change in the variation of the measurement beams MBa and MBb (i.e., beams LBa and LBb), and the second imaging element 34G can detect the component of tilt change in the variation of the measurement beams MBa and MBb (i.e., beams LBa and LBb).

[0073] Figure 7This diagram schematically illustrates the states of the light beams MBa and MBb projected onto the imaging surface of the first imaging element 34C. Figure 8 This diagram schematically illustrates the state of the spotlights MBa and MBb projected onto the imaging surface of the second imaging element 34G. Figure 7 In the middle, the Y-axis and Z-axis set on the shooting surface are related to the... Figures 4-6 The Y-axis and Z-axis of the vertical coordinate system XYZ, respectively, correspond to the Y-direction and Z-direction displacement directions of the beams LBa and LBb on the emission surfaces of the laser sources 10A and 10B, respectively. The reference point CFa set on the imaging surface represents the position of the beam MBa used for projection measurement when the beam LBa from the laser source 10A is emitted without parallel displacement. Similarly, the reference point CFb set on the imaging surface represents the position of the beam MBb used for projection measurement when the beam LBb from the laser source 10B is emitted without parallel displacement.

[0074] like Figure 7 As shown, when beam MBa is offset relative to reference point CFa in the -Y and +Z directions, beam LBa emitted from the emission outlet of laser source 10A is offset parallel to the -Y and +Z directions. Similarly, the offset of the projection position of beam MBb relative to reference point CFb represents the parallel offset of beam LBb emitted from the emission outlet of laser source 10B in the Y or Z direction. The image information of the imaging element 34C is analyzed and processed by a control unit (not shown), thereby determining the error amount of parallel shift of beams LBa and LBb (the offset of beam MBa from reference point CFa and the offset of beam MBb from reference point CFb). Based on the determined error amount, for beam LBa, by... Figure 4 The illustrated correction optical system 11A corrects the parallel shift error for beam LBb, through... Figure 4 The corrective optical system 11B shown corrects the error of parallel shift.

[0075] In addition, Figure 8 In the image, the θy axis, set on the imaging surface of the second imaging element 34G, represents the tilt of the beams LBa and LBb at the respective emission outlets of laser sources 10A and 10B in the Y direction within the XY plane, and the θz axis represents the tilt of the beams LBa and LBb at the respective emission outlets of laser sources 10A and 10B in the Z direction within the XZ plane. Furthermore, the reference point CFg on the imaging surface represents the position where the measurement beams MBa and MBb are projected when the beams LBa and LBb from laser sources 10A and 10B are emitted without tilt. Moreover, when laser sources 10A and 10B are fiber amplifier laser sources, the θz direction also becomes the departure orientation of the wavelength conversion element (crystallizing higher harmonics such as 2nd and 3rd harmonics) installed internally.

[0076] exist Figure 8 In the example, the spot light of beam MBa is approximately aligned with the reference point CFg, while the spot light of beam MBb is shifted from the reference point CFg towards the -θz direction and projected. Therefore, beam LBb from laser source 10B is emitted obliquely from the emission outlet towards the -θz direction. The image information from the imaging element 34G is analyzed and processed by a control unit (not shown), thereby determining the tilt error amounts (the offset of the spot light of beam MBa from the reference point CFg and the offset of the spot light of beam MBb from the reference point CFg) for beams LBa and LBb respectively. Based on the determined tilt error amounts, for beam LBa, by... Figure 4 The illustrated correction optical system 11A corrects tilt error for beam LBb by... Figure 4 The shown optical correction system 11B corrects tilt error.

[0077] Furthermore, since the spot beams MBa and MBb projected onto the imaging surface of the second imaging element 34G are each designed to be located at the reference point CFg, therefore, for example, as Figure 8 As shown, even when the images are taken at offset points, it is impossible to determine whether these points of light originate from the beam MBa used for measuring beam LBa or from the beam MBb used for measuring beam LBb. Therefore, when drawing a pattern on the sheet substrate P, taking advantage of the existence of periods during which only laser light source 10A emits beam LBa and periods during which only laser light source 10B emits beam LBb, the image information from the imaging element 34G can be sampled at the timing of projecting either beam MBa or MBb onto the imaging surface of the imaging element 34G.

[0078] Alternatively, it can also be in Figure 4 A shutter (movable light shield) is set in either or both of the optical paths of the measuring beam MBa between the beam splitter 30A and the triangular mirror 33 and the measuring beam MBb between the beam splitter 30B and the triangular mirror 33, so that at least one of the beams MBa and MBb is not projected onto the imaging surface of the imaging element 34G.

[0079] Figure 9 It is shown Figure 4 , Figure 5 The corrective optical system 11B shown Figure 4 A three-dimensional diagram of an example of the specific optical structure of the correction optical system 11A (which is the same in the diagram). Figure 9 The vertical coordinate system XYZ is set to be the same as that in Figures 4-6 The vertical coordinate systems XYZ are set to be the same in each component. (Source: Beam splitter 30B, reference...) Figure 5A beam LBb (parallel beam) is incident on a beam shifter consisting of a quartz parallel plate HV1, which is tilted about a center line SF1 perpendicular to the optical axis AXb and parallel to the Y-axis, and a quartz parallel plate HV2, which is tilted about a center line SF2 perpendicular to the optical axis AXb and parallel to the Z-axis. The beam LBb is shifted parallel to the Z-axis by the tilting of parallel plate HV1, and parallel to the Y-axis by the tilting of parallel plate HV2.

[0080] The light beam LBb, after passing through the parallel plate HV2, passes through a quartz prism plate RD1, which can rotate around the optical axis AXb, and then through a quartz prism plate RD2, which can also rotate around the optical axis AXb. Prisms RD1 and RD2 are respectively formed as wedges with a first face perpendicular to the optical axis AXb and a second face inclined relative to that first face. By adjusting the angles of the two prism plates RD1 and RD2 around the optical axis AXb, the tilt of the travel direction of the light beam LBb emitted from prism plate RD2 can be finely adjusted.

[0081] The tilt adjustment of parallel plates HV1 and HV2, and the rotation angle adjustment of prism plates RD1 and RD2, can also be implemented with the following structure: based on the... Figure 6 The parallel shift error and tilt error measured by the imaging elements 34C and 34G shown are respectively driven by actuators controlled by commands from a control unit (not shown). Furthermore, Figure 4 The corrective optical system 11A shown also... Figure 9 The correction optical system 11B shown is similarly configured.

[0082] In this embodiment, portions of the beams LBa and LBb emitted from two spatially separated laser light sources 10A and 10B are split by beam splitters 30A and 30B (one of 30A and 30B corresponds to the first beam splitter, and the other corresponds to the second beam splitter) to form measurement beams MBa and MBb. The winding (configuration of mirrors, etc.) and length of the optical paths up to the beam variation detection unit 34 are set to be identical for both the MBa and MBb sides. Furthermore, the length of the optical path up to the triangular mirror 33, which combines the two measurement beams MBa and MBb into a parallel and closely approximate state, can be set to be relatively long. Therefore, even small variations (parallel shift error, tilt error) of the beams LBa and LBb emitted from the laser light sources 10A and 10B can be captured as relatively large positional shifts on the imaging surfaces of the imaging elements 34C and 34G.

[0083] according to Figures 1-5As can be seen from the structure, if the relative positional relationship and relative tilt of the beam LBa emitted from laser source 10A and the beam LBb emitted from laser source 10B change, then errors will occur in the relative positional relationship between the odd-numbered drawing lines SL1, SL3, SL5 and the even-numbered drawing lines SL2, SL4, SL6, resulting in a decrease in the joining accuracy of the patterns drawn by the drawing lines SL1 to SL6 respectively. Therefore, using... Figures 10-14 Explain how the patterns drawn by each drawing line SL1 to SL6 shift position due to the changes in the emission state (parallel shift error and tilt error) of the beams LBa and LBb from each laser source 10A and 10B.

[0084] Figure 10 This means that from Figure 5 The diagram shows a three-dimensional representation of the beam LBb shift state during parallel shifting of the laser beam LBb from the laser source 10B to the primary acousto-optic modulation element AM6. Figure 10 In the process, the beam LBb emitted from the emission outlet of the laser source 10B follows the direction of arrow Ay1 along the specified optical axis AXb (refer to...). Figure 9 When the beam LBb is shifted in the -Y direction (parallel shift), the beam LBb that has just passed through the beam splitter 30B and the correction optics system 11B is also shifted in the -Y direction as shown by arrow Ay2. Therefore, the beam LBb, which is reflected by the beam splitter 12B and travels in the -Y direction, is shifted in the -X direction before it is about to enter the reducing relay optics system 14B. The reducing relay optics system 14B is also an imaging system that forms an inverted image, so the beam LBb emitted from the reducing relay optics system 14B is shifted in the +X direction as shown by arrow Ay3. Furthermore, the beam LBb, which is bent in the +X direction by the reflector 15B2, is incident on the acousto-optic modulation element AM6 in a state of parallel shift from the predetermined optical axis AXb in the -Z direction as shown by arrow Ay4.

[0085] Furthermore, the beam LBb emitted from the emission outlet of the laser source 10B follows the specified optical axis AXb (see arrow Az1). Figure 9When the beam LBb is shifted (parallel shift) in the +Z direction, the beam reflected in the -Z direction by the reflector 15B1 through the beam splitter 30B, the correction optical system 11B, the beam splitter 12B, and the reduction relay optical system 14B is shifted in the -Y direction as shown by arrow Az3. Therefore, the beam LBb, which is bent in the +X direction by the reflector 15B2, is incident on the acousto-optic modulation element AM6 in a state of parallel shift from the predetermined optical axis AXb in the -Y direction as shown by arrow Az4. In addition, when the beam LBb emitted from the emission outlet of the laser source 10B is parallel shifted as shown by arrow Ay1, the measurement beam MBb reflected by the beam splitter 30B is shifted in the -X direction as shown by arrow Ay5. When the beam LBb emitted from the laser source 10B is parallel shifted as shown by arrow Az1, the measurement beam MBb is shifted in the +Z direction as shown by arrow Az5.

[0086] Figure 11 It is exaggerated to show the beam LBb from the laser source 10B as... Figure 10 The diagram shows the state of the beams LB2, LB4, and LB6 used to depict the even-numbered depicting units MU2, MU4, and MU6 when the arrow Ay1 is shifted parallel to the -Y direction. Figure 11 For ease of understanding, no further explanation was provided. Figure 9 The correction optical system 11B shown adjusts the position and tilt of the beam LBa. Furthermore, the beam LBb from the laser source 10B is connected in series through... Figure 4 The even-numbered acousto-optic modulation elements AM6, AM4, and AM2 described herein, therefore, in Figure 11 The upper section shows the optical path from the primary acousto-optic modulator AM6 to the condenser lens 16B, the incident mirror IM6, and the collimating lens 17B; the middle section shows the optical path from the second-stage acousto-optic modulator AM4 to the condenser lens 20B, the incident mirror IM4, and the collimating lens 21B; and the lower section shows the optical path from the third-stage acousto-optic modulator AM2 to the condenser lens 24B, the incident mirror IM2, and the collimating lens 25B. Additionally, Figure 10 The vertical coordinate system XYZ is set to be parallel to... Figure 4 as well as Figure 5 The vertical coordinate system XYZ is the same.

[0087] like Figure 11 As shown, when the light beam LBb incident on the primary acousto-optic modulation element AM6 is relative to the specified optical axis AXb, as... Figure 10As shown by arrow Ay4, when shifted parallel to the -Z direction, the 0th-order diffracted beam, which is not deflected by the acousto-optic modulator AM6 in the on state and travels in a straight line, intersects the optical axis AXb at the rear focal point of the condenser lens 16B, i.e., at the position of the incident mirror IM6. After passing through the collimating lens 17B, it becomes a parallel beam parallel to the optical axis AXb again and enters the 2nd-order acousto-optic modulator AM4 in a state of parallel shift in the +Z direction. The 1st-order diffracted beam, which is deflected by the on-state acousto-optic modulator AM6 at a specified diffraction angle, converges at the position of the incident mirror IM6 as the beam waist, serving as the depiction beam LB6.

[0088] The acousto-optic modulation element AM6 is positioned at the front focal point of the condenser lens 16B, and the reflector mirror IM6 is positioned at the rear focal point of the condenser lens 16B. Therefore, the beam LB6 from the condenser lens 16B toward the reflector mirror IM6 is tilted in the XZ plane and is not parallel to the optical axis AXb. However, the beam waist of the beam LB6, which converges at the position of the reflector mirror IM6, is located in the YZ plane, and does not change even if the beam LBb incident on the acousto-optic modulation element AM6 is parallelly shifted as shown by arrow Ay4. However, the beam LB6 reflected by the reflector mirror IM6 is relative to the beam expanders of the lenses LGa and LGb in the drawing unit MU6 (see reference). Figure 2 The extension of the optical axis, namely the optical axis AX6, is inclined in the -X direction within the XZ plane.

[0089] When the primary acousto-optic modulator AM6 is off, the incident beam LBb, as indicated by arrow Ay4, is parallelly shifted in the -Z direction. LBb then passes through AM6, condenser lens 16B, and collimating lens 17B, and is incident on the second-order acousto-optic modulator AM4 with a parallel shift in the +Z direction within the XZ plane. Here, AM4 is also positioned at the front focal point of condenser lens 20B, and mirror IM4 is positioned at the rear focal point of condenser lens 20B. When AM4 is on, the 0th-order diffracted beam, which is not deflected by AM4 and travels in a straight line, intersects the optical axis AXb at the rear focal point of condenser lens 20B (i.e., the position of mirror IM4). It then passes through collimating lens 21B again, becoming a parallel beam parallel to the optical axis AXb, and is incident on the third-order acousto-optic modulator AM2 with a parallel shift in the -Z direction.

[0090] Furthermore, the first-order diffracted beam LB4, deflected at a predetermined diffraction angle by the acousto-optic modulation element AM4 when it is in the activated state, converges at the position of the reflection mirror IM4 in a manner that forms the beam waist. The beam LB4 from the condenser lens 20B toward the reflection mirror IM4 is tilted in the XZ plane, not parallel to the optical axis AXb. However, the position of the beam waist of the beam LB4 converging at the position of the reflection mirror IM4 does not change in the YZ plane even if the beam LBb incident on the acousto-optic modulation element AM4 is shifted parallel to the +Z direction. However, the beam LB4 reflected by the reflection mirror IM4 is relative to the beam expanders (see reference) of the lenses LGa and LGb within the depiction unit MU4. Figure 2 The extension of the optical axis, namely the optical axis AX4, is inclined in the -X direction within the XZ plane.

[0091] With both the primary acousto-optic modulator AM6 and the secondary acousto-optic modulator AM4 in the off state, and the incident light beam LBb, as indicated by arrow Ay4, shifts parallel in the -Z direction, it passes through AM6, condenser lens 16B, collimating lens 17B, AM4, condenser lens 20B, and collimating lens 21B, before entering the tertiary acousto-optic modulator AM2 in the -Z direction within the XZ plane. Here, AM2 is also positioned at the front focal point of condenser lens 24B, and mirror IM2 is positioned at the rear focal point of condenser lens 24B. When the acousto-optic modulation element AM2 is in the ON state, the 0th order diffracted beam that is not deflected by the acousto-optic modulation element AM2 and travels in a straight line intersects the optical axis AXb at the position of the rear focal point of the condenser lens 24B, i.e. the position of the incident mirror IM4, and then becomes a parallel beam parallel to the optical axis AXb again through the collimating lens 25B.

[0092] Furthermore, the first-order diffracted beam LB2, deflected at a predetermined diffraction angle by the acousto-optic modulation element AM2 in the activated state, converges at the position of the reflection mirror IM2 in a manner that forms the beam waist. The beam LB2 from the condenser lens 24B toward the reflection mirror IM2 is tilted in the XZ plane, not parallel to the optical axis AXb. However, the position of the beam waist of the beam LB2 converging at the position of the reflection mirror IM2 does not change in the YZ plane even if the beam LBb incident on the acousto-optic modulation element AM2 is shifted parallel to the -Z direction. However, the beam LB2 reflected by the reflection mirror IM2 is relative to the beam expanders (see reference) of the lenses LGa and LGb within the depiction unit MU2. Figure 2 The extension of the optical axis, namely the optical axis AX2, is inclined in the -X direction within the XZ plane.

[0093] As described above, in the beam LBb emitted from the laser source 10B, Figure 10When the beams are shifted parallel to each other in the Y direction as shown by arrow Ay1, the positions of the beam waists of the beams LB6, LB4, and LB2 formed at the respective positions of the incident mirrors IM6, IM4, and IM2 do not change. These beam waists (focus points) are conjugate (imaging relationship) with the point beams SP of the beams LB6, LB4, and LB2 ultimately projected from the drawing units MU6, MU4, and MU2 onto the sheet substrate P, respectively. Therefore, even if the beam LBb emitted from the laser source 10B is as follows... Figure 10 The arrow Ay1 is shifted parallel to the Y direction, and the positions of the even-numbered lines SL6, SL4, and SL2 will not change.

[0094] The same applies to the odd-numbered drawing units MU1, MU3, and MU5, which are supplied with beam LBa from laser source 10A, even if the beam LBa emitted from laser source 10A is... Figure 4 Even if the line is shifted parallel to the center in the Y direction, the positions of the odd-numbered lines SL1, SL3, and SL5 will not change. However, if... Figure 11 As shown, the beams LB1 to LB6 from each of the incident mirrors IM1 to IM6 toward each of the depicting units MU1 to MU6 are tilted in the XZ plane.

[0095] These tilts, known as telecentric error, are the tilts of the centerlines of the light beams LB1-LB6 projected onto the surface of the sheet substrate P relative to the normal to the surface of the sheet substrate P. Because the effect of telecentric error (positional shift of the point light SP in the sub-scanning direction) occurs during defocusing, the focusing surfaces of light beams LB1-LB6, acting as the focusing planes of the point light SP and the surface of the sheet substrate P, can always be set within the depth of focus range. When the effect of telecentric error cannot be ignored, by... Figure 9 The parallel plate HV2 shown can be adjusted so that the beams LBa and LBb from the laser sources 10A and 10B move parallel to each other in the Y direction.

[0096] Next, refer to Figure 12 For the beam LBb emitted from the emission outlet of laser source 10B, Figure 10 The case of parallel displacement in the +Z direction, as shown by arrow Az1, will be explained. Figure 12 It is exaggerated to show the beam LBb from the laser source 10B as... Figure 10 The diagram shows the state of the beams LB2, LB4, and LB6 used to depict the even-numbered depicting units MU2, MU4, and MU6 when the beam is shifted parallel to the +Z direction as indicated by arrow Az1. Additionally... Figure 12 The vertical coordinate system XYZ and Figure 4 The vertical coordinate system XYZ is the same. For example, in... Figure 10 As explained, when the beam LBb from the laser source 10B is shifted parallel to the +Z direction as indicated by arrow Az1, the beam LBb incident on the primary acousto-optic modulation element AM6 is shifted parallel to the -Y direction relative to the specified optical axis AXb as indicated by arrow Az4.

[0097] When the acousto-optic modulation elements AM6, AM4, and AM2 are each in their on-state, the diffraction direction is in the -Z direction within a plane parallel to the XZ plane. Therefore, in Figure 12 In this process, the first-order diffracted beam LB6 emitted from the acousto-optic modulator AM6 (in the on state) propagates parallel to the optical axis AXb in the XY plane and is incident on the condenser lens 16B. The beam LB6, passing through the condenser lens 16B, forms a beam waist at the center of the reflecting surface of the reflector IM6 in the Y direction (a position offset from the optical axis AXb towards the -Z direction) and is reflected in the -Z direction. Meanwhile, the 0th-order diffracted beam from the acousto-optic modulator AM6 intersects the optical axis AXb in the space above the reflector IM6, passes through the collimating lens 17B, and becomes a parallel beam parallel to the optical axis AXb before being incident on the second-order acousto-optic modulator AM4. Therefore, even if the beam LBb incident on the acousto-optic modulator AM6 shifts parallel in the Y direction as indicated by arrow Az4, the position of the beam waist of the beam LB6, which is focused at the position of the reflector IM6, does not change in the XY plane.

[0098] The incident light beam LBb, which is parallel to the optical axis AXb, is incident on the acousto-optic modulator AM6 in the Y direction, as indicated by arrow Az4. When the primary acousto-optic modulator AM6 is in the Off state, the light beam LBb, which is parallel to the optical axis AXb in the -Y direction, is incident on the acousto-optic modulator AM4. If the acousto-optic modulator AM4 is turned on, the light beam LB4, which is a first-order diffracted beam emitted from the acousto-optic modulator AM4, travels parallel to the optical axis AXb in the XY plane and is incident on the condenser lens 20B. The light beam LB4 passing through the condenser lens 20B forms a beam waist at the center of the reflecting surface of the reflection mirror IM4 in the Y direction (the position offset from the optical axis AXb in the -Z direction) and is reflected in the -Z direction.

[0099] On the other hand, the 0th-order diffracted beam from the acousto-optic modulator AM4, after intersecting the optical axis AXb in the space above the incident mirror IM4, passes through the collimating lens 21B and becomes a parallel beam parallel to the optical axis AXb before entering the 3rd-order acousto-optic modulator AM2. Therefore, even if the beam LBb incident on the primary acousto-optic modulator AM6 is displaced parallel in the Y direction as shown by arrow Az4, the position of the beam waist of the beam LB4 focused at the location of the incident mirror IM4 does not change in the XY plane.

[0100] Similarly, the beam LBb incident on the acousto-optic modulator AM6 is shifted parallel to the optical axis in the Y direction as indicated by arrow Az4. When both the primary acousto-optic modulator AM6 and the second-order acousto-optic modulator AM4 are in the off state, the beam LBb, shifted parallel to the optical axis AXb in the -Y direction, is incident on the acousto-optic modulator AM2. If the acousto-optic modulator AM2 is turned on, the beam LB2, which is a first-order diffracted beam emitted from the acousto-optic modulator AM2, travels parallel to the optical axis AXb in the XY plane and is incident on the condenser lens 24B. The beam LB2 passing through the condenser lens 24B forms a beam waist at the center of the reflecting surface of the reflection mirror IM2 in the Y direction (the position shifted from the optical axis AXb towards the -Z direction) and is reflected in the -Z direction. In addition, the 0th-order diffracted beam from the acousto-optic modulator AM2 intersects the optical axis AXb in the space above the reflection mirror IM2, and then passes through the collimating lens 25B, becoming a parallel beam parallel to the optical axis AXb and traveling forward. Therefore, even if the beam LBb incident on the primary acousto-optic modulation element AM6 is displaced parallel to the Y direction as indicated by arrow Az4, the position of the beam waist of the beam LB4 focused at the position of the incident mirror IM4 does not change on the XY plane.

[0101] As described above, in the beam LBb emitted from the laser source 10B, Figure 10 Even when the beams are shifted parallel to each other in the Z direction as shown by arrow Az1, the positions of the beam waists of the beams LB6, LB4, and LB2 formed at the respective positions of the incident mirrors IM6, IM4, and IM2 do not change. Therefore, even if the beam LBb emitted from the laser source 10B is as shown... Figure 10 Like the arrow Az1, it shifts parallel in the Z direction, and the positions of the even-numbered lines SL6, SL4, and SL2 will not change.

[0102] The same applies to the odd-numbered drawing units MU1, MU3, and MU5, which are supplied with beam LBa from laser source 10A, even if the beam LBa emitted from laser source 10A is... Figure 4 Even if the line is shifted parallel to the center in the Z direction, the positions of the odd-numbered lines SL1, SL3, and SL5 will not change. However, if... Figure 12 As shown, in the beams LB1-LB6 directed from each of the incident mirrors IM1-IM6 towards each of the drawing units MU1-MU6, a telecentric error is generated relative to the plane parallel to the XZ plane. Therefore, when the effect of the telecentric error cannot be ignored, by... Figure 9 The parallel plate HV1 shown allows the beams LBa and LBb from laser sources 10A and 10B to be moved parallel to each other in the Z direction, thus adjusting the incident state (coaxiality with the optical axis AXb) of the primary acousto-optic modulation elements AM6 and AM1.

[0103] Next, the case where the laser beam LBb is emitted obliquely from the emission port of the laser source 10B will be explained. The emission port of the laser source 10B passes through... Figure 4 , Figure 5 , Figure 10 The respective correction optical system 11B and reduction relay optical system 14B are configured to be in a crystal conjugate relationship with the primary acousto-optic modulation element AM6. If the reduction ratio of the reduction relay optical system 14B is set to 1 / Mb (Mb>1), the tilt angle of the incident beam LBb relative to the optical axis AXb at the acousto-optic modulation element AM6 becomes larger than the tilt angle of the beam LBb at the exit of the laser source 10B relative to the optical axis AXb by a ratio corresponding to the reciprocal of the reduction ratio 1 / Mb.

[0104] Figure 13 This diagram exaggerates the state of the beam LBb incident on the primary acousto-optic modulation element AM6 when it is tilted relative to the optical axis AXb in a plane parallel to the XZ plane, pointing towards the respective drawing beams LB2, LB4, and LB6 of the even-numbered drawing units MU2, MU4, and MU6. (Before proceeding...) Figure 9 In the corrected optical system 11B shown, with the two prism plates RD1 and RD2 correcting the tilt of the beam LBb, when the beam LBb from the emission outlet of the laser source 10B is tilted in the Y direction within a plane parallel to the XY plane, the beam LBb incident on the acousto-optic modulation element AM6 is tilted relative to the optical axis AXb within a plane parallel to the XZ plane. Furthermore, Figure 13 The vertical coordinate system XYZ is set to be the same as the previous one. Figure 4 , Figure 12 The vertical coordinate system XYZ is the same.

[0105] like Figure 13 As shown, if the light beam LBb incident on the primary acousto-optic modulator AM6 (set to the ON state) is slightly tilted counterclockwise relative to the optical axis AXb in a plane parallel to the XZ plane, then the 0th-order diffracted beam, not diffracted by the acousto-optic modulator AM6, is incident on the condenser lens 16B at an angle relative to the optical axis AXb. This 0th-order diffracted beam travels slightly off-center from the optical axis AXb towards the +Z direction in the optical path from the condenser lens 16B to the collimating lens 17B, parallel to the optical axis AXb, and forms a beam waist in the space above the intermediate incident mirror IM6. The 0th-order diffracted beam exiting the collimating lens 17B travels at a slightly clockwise angle relative to the optical axis AXb in a plane parallel to the XZ plane.

[0106] On the other hand, the beam LB6, a first-order diffracted beam diffracted by the acousto-optic modulation element AM6, is deflected at a predetermined diffraction angle relative to the 0th-order diffracted beam and incident on the condenser lens 16B. However, the beam LB6 exiting the condenser lens 16B travels parallel to the optical axis AXb in the optical path away from the optical axis AXb in the -Z direction, and is reflected in the -Z direction by the reflection mirror IM6 in a manner parallel to the optical axis AX6. However, the beam LB6 reflected by the reflection mirror IM6 is deflected in the -X direction relative to the optical axis AX6. Therefore, the focal point of the beam LB6, which becomes the beam waist, is shifted in the XY plane from its original position on the optical axis AX6 in the -X direction. Consequently, the point light SP of the beam LB6 projected from the drawing unit MU6 onto the sheet substrate P also moves in the sub-scanning direction corresponding to the -X direction. Figure 2 Displacement in the Xt direction.

[0107] Furthermore, the beam LBb incident on the acousto-optic modulator AM6 is slightly tilted counterclockwise relative to the optical axis AXb in a plane parallel to the XZ plane. When the primary acousto-optic modulator AM6 is off, the beam LBb is slightly tilted clockwise relative to the optical axis AXb in a plane parallel to the XZ plane and incident on the acousto-optic modulator AM4. If the acousto-optic modulator AM4 is on, the 0th-order diffracted beam not diffracted by the acousto-optic modulator AM4 is incident on the condenser lens 20B at an angle relative to the optical axis AXb. This 0th-order diffracted beam travels slightly off-center from the optical axis AXb in the -Z direction in the optical path from the condenser lens 20B to the collimating lens 21B, parallel to the optical axis AXb, and forms a beam waist in the space above the intermediate reflection mirror IM4. The 0th-order diffracted beam emitted from the collimating lens 21B travels slightly tilted counterclockwise relative to the optical axis AXb in a plane parallel to the XZ plane.

[0108] On the other hand, the beam LB4, a first-order diffracted beam diffracted by the acousto-optic modulation element AM4, is deflected at a predetermined diffraction angle relative to the 0th-order diffracted beam and incident on the condenser lens 20B. However, the beam LB4 exiting the condenser lens 20B travels parallel to the optical axis AXb in the optical path away from the optical axis AXb in the -Z direction, and is reflected in the -Z direction by the reflection mirror IM4 in a manner parallel to the optical axis AX4. However, the beam LB4 reflected by the reflection mirror IM4 is deflected in the -X direction relative to the optical axis AX4. Therefore, the focal point of the beam LB4, which becomes the beam waist, is shifted in the XY plane from its original position on the optical axis AX4 in the -X direction. Consequently, the point light SP of the beam LB4 projected from the drawing unit MU4 onto the sheet substrate P also moves in the sub-scanning direction corresponding to the -X direction. Figure 2 Displacement in the Xt direction.

[0109] Furthermore, the beam LBb incident on the acousto-optic modulator AM6 is slightly tilted counterclockwise relative to the optical axis AXb in a plane parallel to the XZ plane. When both acousto-optic modulators AM6 and AM4 are off, the beam LBb is incident on the acousto-optic modulator AM2 with a slight counterclockwise tilt relative to the optical axis AXb in a plane parallel to the XZ plane. If the acousto-optic modulator AM2 is on, the 0th-order diffracted beam not diffracted by the acousto-optic modulator AM2 is incident on the condenser lens 24B with a tilt relative to the optical axis AXb. This 0th-order diffracted beam travels slightly off-center from the optical axis AXb in the +Z direction in the optical path from the condenser lens 24B to the collimating lens 25B, parallel to the optical axis AXb, and forms a beam waist in the space above the intermediate mirror IM2. The 0th-order diffracted beam emitted from the collimating lens 25B travels with a slight clockwise tilt relative to the optical axis AXb in a plane parallel to the XZ plane.

[0110] On the other hand, the beam LB2, a first-order diffracted beam diffracted by the acousto-optic modulation element AM2, is deflected at a predetermined diffraction angle relative to the 0th-order diffracted beam and incident on the condenser lens 24B. However, the beam LB2 exiting the condenser lens 24B travels parallel to the optical axis AXb in the optical path away from the optical axis AXb in the -Z direction, and is reflected in the -Z direction by the reflection mirror IM2 in a manner parallel to the optical axis AX2. However, the beam LB2 reflected by the reflection mirror IM2 is deflected in the -X direction relative to the optical axis AX4. Therefore, the focal point of the beam LB2, which becomes the beam waist, is shifted in the XY plane from its original position on the optical axis AX2 in the -X direction. Consequently, the point light SP of the beam LB2 projected from the drawing unit MU2 onto the sheet substrate P also moves in the sub-scanning direction corresponding to the -X direction. Figure 2 Displacement in the Xt direction.

[0111] As described above, when the beam LBb emitted from the laser source 10B is in contact with... Figure 5 or Figure 9 When the plane parallel to the XY plane is tilted relative to the specified optical axis AXb, the positions of the beam waists of the beams LB6, LB4, and LB2 formed at the respective positions of the incident mirrors IM6, IM4, and IM2 are all displaced in the +X or -X direction. Therefore, the positions of the even-numbered drawing lines SL6, SL4, and SL2 in the sub-scanning direction ( Figure 2 The direction of change is Xt. This also applies to the odd-numbered drawing units MU1, MU3, and MU5, which are supplied with the beam LBa from the laser source 10A, when the beam LBa emitted from the laser source 10A changes in the direction of Xt. Figure 4When the XY planes are tilted relative to the designated optical axis (the designed optical axis) within the parallel planes, the beam waists of the beams LB1, LB3, and LB5 formed at the respective positions of the incident mirrors IM1, IM3, and IM5 are displaced in the +X or -X direction. Therefore, the positions of the odd-numbered drawing lines SL1, SL3, and SL5 in the sub-scanning direction ( Figure 2 It changes in the Xt direction.

[0112] Figure 14 This diagram exaggerates the state of the beam LBb from the emission outlet of laser source 10B, which is tilted relative to the optical axis AXb in a plane parallel to the XZ plane. As a result, when the beam LBb incident on the primary acousto-optic modulation element AM6 is tilted relative to the optical axis AXb in a plane parallel to the XY plane, it shows the states of the beams LB2, LB4, and LB6 used for depicting the even-numbered depicting units MU2, MU4, and MU6, respectively. (This is without further context.) Figure 9 In the state where the two prism plates RD1 and RD2 in the corrected optical system 11B are correcting the tilt of the beam LBb, when the beam LBb from the emission outlet of the laser source 10B is tilted in the Z direction in a plane parallel to the XZ plane, the beam LBb incident on the acousto-optic modulation element AM6 is tilted relative to the optical axis AXb in a plane parallel to the XY plane. Furthermore, Figure 14 The vertical coordinate system XYZ is set to be the same as the previous one. Figure 4 , Figure 12 The vertical coordinate system XYZ is the same.

[0113] like Figure 14 As shown, if the light beam LBb incident on the primary acousto-optic modulator AM6 (set to the ON state) is slightly tilted clockwise relative to the optical axis AXb in a plane parallel to the XY plane, the 0th-order diffracted beam, not diffracted by the acousto-optic modulator AM6, travels straight in the XY plane in the same direction as the incident beam LBb and is incident on the condenser lens 16B. This 0th-order diffracted beam travels slightly off-center from the optical axis AXb towards the -Y direction in the optical path from the condenser lens 16B to the collimating lens 17B, parallel to the optical axis AXb, and forms a beam waist in the space above the intermediate reflection mirror IM6. The 0th-order diffracted beam exiting the collimating lens 17B travels slightly counterclockwise relative to the optical axis AXb in a plane parallel to the XY plane.

[0114] On the other hand, the beam LB6, a first-order diffracted beam diffracted by the acousto-optic modulation element AM6, travels through the same optical path as the 0th-order diffracted beam in the XY plane and is deflected in the -Z direction at a predetermined diffraction angle before entering the condenser lens 16B. The beam LB6 exiting the condenser lens 16B travels parallel to the optical axis AXb in the optical path departing from the optical axis AXb in the -Y direction, and is reflected in the -Z direction by the reflection mirror IM6 in a manner parallel to the optical axis AX6. However, the beam LB6 reflected by the reflection mirror IM6 is deflected in the -Y direction relative to both the optical axes AXb and AX6. Therefore, the focal point of the beam LB6, which becomes the beam waist, shifts in the XY plane from its original position on the optical axis AX6 towards the -Y direction. Consequently, the point light SP of the beam LB6 projected from the drawing unit MU6 onto the sheet substrate P also shifts towards the main scanning direction corresponding to the -Y direction. Figure 2 The displacement is in the Yt direction. That is, the entire drawing line SL6 formed by the scanning of the point light of beam LB6 is shifted from its designed position toward the main scanning direction.

[0115] Furthermore, the incident light beam LBb onto the acousto-optic modulation element AM6, as Figure 14 In a plane parallel to the XY plane, the beam LBb is slightly inclined clockwise relative to the optical axis AXb. With the acousto-optic modulator AM6 off, the beam LBb is incident on the acousto-optic modulator AM4 in a slightly counterclockwise direction relative to the optical axis AXb within the plane parallel to the XY plane. If the acousto-optic modulator AM4 is on, the 0th-order diffracted beam, not diffracted by the acousto-optic modulator AM4, travels linearly in the XY plane in the same direction as the incident beam LBb, and is incident on the condenser lens 20B at an angle. This 0th-order diffracted beam travels slightly off-center from the optical axis AXb towards the -Y direction in the optical path from the condenser lens 20B to the collimating lens 21B, parallel to the optical axis AXb, forming a beam waist in the space above the intermediate reflection mirror IM4. The 0th-order diffracted beam emitted from the collimating lens 21B travels slightly counterclockwise relative to the optical axis AXb within the plane parallel to the XY plane.

[0116] On the other hand, the beam LB4, a first-order diffracted beam diffracted by the acousto-optic modulation element AM4, travels through the same optical path as the 0th-order diffracted beam in the XY plane and is deflected relative to the 0th-order diffracted beam in the -Z direction at a predetermined diffraction angle before entering the condenser lens 20B. The beam LB4 exiting the condenser lens 20B travels parallel to the optical axis AXb in the optical path departing from the optical axis AXb in the -Y direction, and is reflected by the reflection mirror IM4 in the -Z direction parallel to the optical axis AX4. However, the beam LB4 reflected by the reflection mirror IM2 is deflected in the -Y direction relative to both the optical axes AXb and AX4. Therefore, the focal point of the beam LB4, which becomes the beam waist, shifts in the XY plane from its original position on the optical axis AX4 in the -Y direction. Consequently, the point light SP of the beam LB4 projected from the drawing unit MU4 onto the sheet substrate P also shifts in the sub-scanning direction corresponding to the -Y direction. Figure 2 The displacement is in the Xt direction. That is, the entire drawing line SL4 formed by scanning the point light of beam LB4 is shifted from its designed position towards the main scanning direction. The direction of displacement of the drawing line SL4 on the sheet substrate P is the same as the direction of displacement of the drawing line SL6.

[0117] And, as Figure 14 As shown, the light beam LBb incident on the acousto-optic modulator AM6 is slightly inclined clockwise relative to the optical axis AXb in a plane parallel to the XY plane. When both acousto-optic modulators AM6 and AM4 are off, the light beam LBb is incident on the acousto-optic modulator AM2, also slightly inclined clockwise relative to the optical axis AXb in a plane parallel to the XY plane. If the acousto-optic modulator AM2 is on, the 0th-order diffracted beam not diffracted by the acousto-optic modulator AM2 is incident on the condenser lens 24B in a state inclined relative to the optical axis AXb in the XY plane. This 0th-order diffracted beam travels slightly off-center from the optical axis AXb in the -Y direction in the optical path from the condenser lens 24B to the collimating lens 25B, parallel to the optical axis AXb, and forms a beam waist in the space above the intermediate mirror IM2. The 0th-order diffracted beam emitted from the collimating lens 25B travels slightly inclined counterclockwise relative to the optical axis AXb in a plane parallel to the XY plane.

[0118] On the other hand, the beam LB2, a first-order diffracted beam diffracted by the acousto-optic modulation element AM2, travels through the same optical path as the 0th-order diffracted beam in the XY plane and is deflected relative to the 0th-order diffracted beam in the -Z direction at a predetermined diffraction angle before entering the condenser lens 24B. The beam LB2 exiting the condenser lens 24B travels parallel to the optical axis AXb in the optical path departing from the optical axis AXb in the -Y direction, and is reflected by the reflection mirror IM2 in the -Z direction parallel to the optical axis AX2. However, the beam LB2 reflected by the reflection mirror IM2 is deflected in the -Y direction relative to both the optical axes AXb and AX2. Therefore, the focal point of the beam LB2, which becomes the beam waist, shifts in the XY plane from its original position on the optical axis AX2 in the -Y direction. Consequently, the point light SP of the beam LB2 projected from the drawing unit MU2 onto the sheet substrate P also shifts in the sub-scanning direction corresponding to the -Y direction. Figure 2 The displacement is in the Xt direction. That is, the entire drawing line SL2, formed by the scanning of the point light of beam LB2, is shifted from its designed position towards the main scanning direction. The direction of displacement of drawing line SL2 is the same as that of drawing lines SL6 and SL4.

[0119] Based on the above, when the beam LBb from the emission outlet of the laser source 10B is tilted relative to the optical axis AXb in the XZ plane, the even-numbered drawing lines SL2, SL4, and SL6 formed on the sheet substrate P are simultaneously in the main scanning direction ( Figure 2 The same amount of shift is applied in the Yt direction. This state is also generated for the odd-numbered beams LB1, LB3, LB5 generated by the beam LBa from the laser source 10A, as well as the odd-numbered drawing lines SL1, SL3, SL5.

[0120] However, the combination of odd-numbered depiction units MU1, MU3, and MU5 and even-numbered depiction units MU2, MU4, and MU6 is a bypass. Figure 4The configuration is shown with the normal of the center point PG rotated by 180°. Therefore, when the beam LBa emitted from the laser source 10A and the beam LBb emitted from the laser source 10B are both tilted in the +Z or -Z direction in the XZ plane relative to the predetermined optical axis, the odd-numbered drawing lines SL1, SL3, SL5 and the even-numbered drawing lines SL2, SL4, SL6 are shifted in opposite directions in the Y (Yt) direction on the sheet substrate P. Conversely, when the beam LBa emitted from the laser source 10A is tilted in the +Z direction in the XZ plane by an angle ΔθLa relative to the predetermined optical axis, and the beam LBb emitted from the laser source 10B is tilted in the -Z direction in the XZ plane by an angle ΔθLb relative to the predetermined optical axis, and the angles ΔθLa and ΔθLb are equal, the odd-numbered drawing lines SL1, SL3, SL5 and the even-numbered drawing lines SL2, SL4, SL6 are shifted by the same amount in the same Y direction.

[0121] As above Figure 11 , Figure 12 As explained, when the beams LBa and LBb from the respective emission outlets of laser sources 10A and 10B undergo a displacement relative to the designed optical axis, although the positions of the drawing lines SL1 to SL6 on the sheet substrate P do not change significantly, a telecentric error occurs. On the other hand, as in Figure 13 , Figure 14 As explained, when the light beams LBa and LBb from the respective emission outlets of laser light sources 10A and 10B undergo a change such as tilting relative to the designed optical axis, the positions of the drawing lines SL1 to SL6 on the sheet substrate P change in the X direction (sub-scanning direction) and Y direction (main scanning direction) depending on the direction and amount of tilt.

[0122] In this embodiment, by Figure 6 The detection unit 34 shown can separate and measure the relative parallel shift and relative tilt variation of the beam LBa from the emission outlet of laser source 10A and the beam LBb from the emission outlet of laser source 10B, thus enabling adjustment. Figure 9 The correction optical systems 11A and 11B shown include parallel plates HV1 and HV2 and prism plates RD1 and RD2 to reduce the connection error caused by the positional variation of the drawing lines SL1 to SL6.

[0123] [Variation Example 1]

[0124] Figure 4The relay imaging systems shown, based on two lenses GL1a and GL2a and two lenses GL1b and GL2b, can each be magnified or reduced beyond the same magnification. For example, the magnification of each relay imaging system can be set as magnification α, which will... Figure 4 The images of the laser sources 10A and 10B, imaged by surfaces Psa and Psb respectively, are magnified by a factor of α. As an example, when the magnification α is set to 4 times (α = 4), the images of the laser sources 10A and 10B are magnified by a factor of α. Figure 6 When the reduction magnification β of the reduction relay optical system based on lenses 34A and 34B is set to 1 / 2 (β = 0.5), the positional displacement of the beams MBa and MBb on the imaging surface of the imaging element 34C becomes twice the error of the parallel displacement of the beams LBa and LBb at each emission outlet of the laser light sources 10A and 10B (= α × β), which can improve the measurement sensitivity.

[0125] Alternatively, the magnification of each of the relay imaging systems based on two lenses GL1a and GL2a and the relay imaging system based on two lenses GL1b and GL2b can be set to a reduction magnification γ, reducing the images at each exit of the laser sources 10A and 10B, which image planes Psa and Psb respectively, to a factor of γ. As an example, when the reduction magnification γ is set to 1 / 2 (γ = 0.5), the images at each exit of the laser sources 10A and 10B can be reduced to a factor of γ. Figure 6 When the magnification β of the reduction relay optical system based on lenses 34A and 34B is also set to 1 / 2 (β = 0.5), the proportionality constant between the change in tilt of the beams LBa and LBb at each exit of the laser light sources 10A and 10B and the displacement of the positions of the light spots of the beams MBa and MBb on the imaging surface of the imaging element 34G is larger than that when the relay imaging system based on lenses GL1a and GL2a and the relay imaging system based on lenses GL1b and GL2b are set to the same magnification, the measurement sensitivity can be improved.

[0126] Based on the above, it can also be configured such that the reduction relay optical system based on lenses 34A and 34B within the detection unit 34 is set to equal magnification (reduction magnification β = 1), and the magnification of the relay imaging system based on lenses GL1a and GL2a and the relay imaging system based on lenses GL1b and GL2b is switched so that the magnification is used when measuring the parallel shift error of beams LBa and LBb emitted from laser light sources 10A and 10B respectively using the imaging element 34C, and the reduction magnification is used when measuring the tilt error of beams LBa and LBb using the imaging element 34G.

[0127] [Second Embodiment]

[0128] Use the previous ones roughly as they were Figures 4 to 10 The beam switching unit (BDU) of the structure enables... Figure 2The internal structure of each of the depiction units MU1 to MU6 is slightly deformed, thereby enabling multi-point scanning by simultaneously projecting two or three point lights from each of the depiction units MU1 to MU6 onto the sheet substrate P and scanning along each of the depiction lines SL1 to SL6.

[0129] Figures 15A-15C This is a diagram illustrating the incident state and diffraction efficiency of the beam LBb from the laser source 10B incident on the primary acousto-optic modulation element AM6 of the beam switching unit BDU. Figure 15A This diagram shows the acousto-optic modulator AM6 as viewed in the XZ plane of the vertical coordinate system XYZ. A beam LBb from the laser source 10B is typically incident on the acousto-optic modulator AM6 coaxially with the optical axis AXb. The acousto-optic modulator AM6 is configured to satisfy the Bragg diffraction condition relative to the incident beam LBb (parallel beam). Therefore, the beam LB6, as a first-order diffracted beam, deflects relative to the optical axis AXb in the -Z direction at a predetermined diffraction angle. Here, if the beam LBb incident on the acousto-optic modulator AM6 is tilted at an incident angle θz in a plane parallel to the XZ plane from its coaxial state with the optical axis AXb, then the beam LB6, as a first-order diffracted beam, is also tilted in a plane parallel to the XZ plane proportionally to this incident angle θz.

[0130] in addition, Figure 15B This diagram shows the acousto-optic modulator AM6 as observed in the XY plane of the vertical coordinate system XYZ. A beam LBb from the laser source 10B is typically incident on the acousto-optic modulator AM6 coaxially with the optical axis AXb. The acousto-optic modulator AM6 is configured to satisfy the Bragg diffraction conditions relative to the incident beam LBb (parallel beam). Therefore, the beam LB6, as a first-order diffracted beam, propagates parallel to the optical axis AXb when observed in the XY plane. Here, if the beam LBb incident on the acousto-optic modulator AM6 is tilted at an incident angle θy in a plane parallel to the XY plane (a plane outside the diffraction direction) from its coaxial state with the optical axis AXb, then the beam LB6, as a first-order diffracted beam, maintains its incident angle θy in the XY plane and propagates in the XZ plane at a predetermined diffraction angle in the -Z direction.

[0131] In Figure 15A The situation and Figure 15B When comparing the cases, the intensity of the beam LB6 (1st order diffracted beam) from the acousto-optic modulation element AM6 is as follows: Figure 15C That's how it's measured. Figure 15C It is a schematic graph showing the incident angle θz of the diffraction direction of the beam LBb incident on the acousto-optic modulation element AM6 and the change of the intensity of the beam LB6 (the first-order diffracted beam) relative to the incident angle θy of the non-diffraction direction. Figure 15CThe horizontal axis represents the incident angles θz and θy, and the origin (0) represents the state in which the beam LBb is coaxially incident on the acousto-optic modulation element AM6 with the optical axis AXb. Figure 15C The vertical axis represents the ratio of the intensity of beam LB6 (the first-order diffracted beam) to the intensity of the incident beam LBb, i.e., the diffraction efficiency (%).

[0132] Figure 15C The characteristic CCz in the curve shown represents Figure 15A The change in diffraction efficiency under the condition of Figure 15C The characteristic CCy in the curve graph shown represents Figure 15B The change in diffraction efficiency under certain conditions. Based on this characteristic of CCz and CCy, it can be seen that under conditions such as… Figure 15A When the incident beam LBb is tilted at an angle θz towards the diffraction direction of the acousto-optic modulator AM6 from its normal state, the diffraction efficiency decreases sharply with respect to the change in the incident angle θz due to the deviation from the conditions of Bragg diffraction. Conversely, in situations such as Figure 15B When the incident beam LBb is tilted at an angle θy from its normal state toward a direction perpendicular to the diffraction direction of the acousto-optic modulation element AM6 (the non-diffraction direction), the decrease in diffraction efficiency relative to the change of the incident angle θy is slow.

[0133] Therefore, in this embodiment, when observed in the XY plane, the two beams (parallel beams) are made as follows within the primary acousto-optic modulation element AM6: Figure 15C As shown, the light beams are intersected at an angle ±θya relative to the optical axis AXb. In this case, the two beams incident on the primary acousto-optic modulation element AM6 are supplied from other laser sources of the same structure (e.g., 10B1, 10B2).

[0134] Figure 16 This is a perspective view showing the state of the two beams in the optical path from the primary acousto-optic modulation element AM6 to the incident mirror IM6 of the beam switching unit BDU in the second embodiment. Figure 16 The vertical coordinate system XYZ is set to be parallel to... Figure 4 The vertical coordinate system XYZ is the same. The two beams (both parallel beams) incident on the primary acousto-optic modulation element AM6 are supplied from other laser sources of the same structure (e.g., 10B1, 10B2) and become beams LSa and LSb, respectively. For example, in... Figure 15CAs explained, the incident angle of beam LSa towards the acousto-optic modulator AM6 in the XY plane is set to -θya from the optical axis AXb, and the incident angle of beam LSb towards the acousto-optic modulator AM6 in the XY plane is set to +θya from the optical axis AXb. The two beams LSa and LSb become parallel beams with diameters of approximately 1 mm to 0.5 mm, respectively. After crossing and advancing within the crystal of the acousto-optic modulator AM6, they directly become straight-advancing 0th-order diffracted beams LSa0 and LSb0 (dashed lines) and are incident on the condenser lens 16B.

[0135] When the acousto-optic modulation element AM6 is in the ON state, a first-order diffracted light beam LSa1 (solid line) deflected at a specified diffraction angle in the -Z direction relative to the 0th-order diffracted light beam LSa0 and a first-order diffracted light beam LSb1 (solid line) deflected at a specified diffraction angle in the -Z direction relative to the 0th-order diffracted light beam LSb0 are generated from the acousto-optic modulation element AM6 and are incident on the condenser lens 16B, respectively. The 0th-order diffracted light beams LSa0 and LSb0 emitted from the condenser lens 16B are shifted parallel to the optical axis AXb by the same distance in the +Y and -Y directions, respectively, in a plane parallel to the XY plane, and then pass through the space above the incident mirror IM6 and are incident on the next collimating lens 17B.

[0136] On the other hand, when observed in the XZ plane, the first-order diffracted light beam LSa1 emitted from the condenser lens 16B is shifted parallel to the -Z direction from the 0th-order diffracted light beam LSa0 and propagates parallel to the optical axis AXb, and is reflected in the -Z direction by the downward 45° reflecting surface of the reflection mirror IM6. Similarly, when observed in the XZ plane, the first-order diffracted light beam LSb1 emitted from the condenser lens 16B is shifted parallel to the -Z direction from the 0th-order diffracted light beam LSb0 and propagates parallel to the optical axis AXb, and is reflected in the -Z direction by the downward 45° reflecting surface of the reflection mirror IM6. Here, the first-order diffracted light beam LSa1 reflected in the -Z direction by the reflecting surface of the reflection mirror IM6 is designated as beam LB6a, and the first-order diffracted light beam LSb1 is designated as beam LB6b.

[0137] As in the previous Figures 11-14 As explained, when the optical axis AX6 is defined as the axis perpendicular to the optical axis AXb and centered on the Y-direction of the reflecting surface of the mirror IM6, beam LB6a advances parallel to the optical axis AX6 in the +Y direction by a predetermined distance ΔYL, and beam LB6b advances parallel to the optical axis AX6 in the -Y direction by a predetermined distance ΔYL. Since the reflecting surface of the mirror IM6 is located at the rear focal point of the condenser lens 16B, beams LB6a and LB6b become divergent beams after reaching the beam waist at the reflecting surface of the mirror IM6. The diameter of the beam waist at the reflecting surface of the mirror IM6 is approximately tens of μm.

[0138] As in the previous Figure 4 As explained, the second-stage acousto-optic modulator AM4 is optically conjugate to the primary acousto-optic modulator AM6 via a relay system of equal magnification consisting of a condenser lens 16B and a collimating lens 17B, and the third-stage acousto-optic modulator AM2 is optically conjugate to the second-stage acousto-optic modulator AM4 via a relay system of equal magnification consisting of a condenser lens 20B and a collimating lens 21B. Therefore, in Figure 16 When the acousto-optic modulator AM6 is in the off state, no first-order diffracted light beams LSa1 and LSb1 are generated. The beams LSa and LSb incident on the acousto-optic modulator AM6, along the optical path of the 0th-order diffracted light beams LSa0 and LSb0, pass directly through the condenser lens 16B and collimating lens 17B and are then incident on the second-order acousto-optic modulator AM4. At this time, the incident angles (tilt angles in the XY plane relative to the optical axis AXb) of the two beams LSa and LSb onto the acousto-optic modulator AM4 are the same as the incident angles of the beams LSa and LSb incident onto the acousto-optic modulator AM6. Similarly, when both the primary acousto-optic modulator AM6 and the second-order acousto-optic modulator AM4 are in the off state, the incident angles (tilt angles in the XY plane relative to the optical axis AXb) of the two beams LSa and LSb onto the third-order acousto-optic modulator AM2 are also the same as the incident angles of the beams LSa and LSb incident onto the acousto-optic modulator AM6.

[0139] Depend on Figure 16 The two beams LB6a and LB6b reflected by the reflector IM6 in the -Z direction become divergent beams, but their principal rays (central rays) are parallel to the optical axis AX6. At the position of the reflector IM6, with the two beams LB6a and LB6b separated in the Y direction, the two beams LB6a and LB6b incident on... Figure 2 The mirror M10 of the depiction unit MU1 (MU2~MU6 are the same) ultimately projects two point lights onto the sheet substrate P at a certain interval in the Y (Yt) direction, i.e., the main scanning direction. Figure 16 The interval 2ΔYL in the middle is offset by a distance reduced at a specified ratio. This is different from the previous... Figure 14 The state described in the text is consistent.

[0140] Therefore, in this embodiment, Figure 1The optical structures of the optical path adjustment units BV1 to BV6 shown are slightly modified. In the previous first embodiment, the optical path adjustment units BV1 to BV6 were respectively composed of a relay optical system based on multiple mirrors and multiple lenses, and a tiltable quartz parallel plate. In this embodiment, a rotator mechanism is provided in the optical path adjustment unit BV6 (and BV1 to BV5 as well). This rotator mechanism rotates the two light beams LB6a and LB6b incident on the initial mirror M10 of the drawing unit MU6 (and MU1 to MU5 as well) by 90 degrees around the optical axis. In the following description, any one of the drawing units MU1 to MU6 is referred to as drawing unit MUn (n = 1 to 6), and the two light beams incident on each drawing unit MUn are sometimes also referred to as light beams LBna and LBnb (n = 1 to 6).

[0141] Figure 17 It is an exaggeration to indicate that it was passed from Figure 16 The incident mirror IM6 shown passes through the optical path adjustment unit BV6 (reference). Figure 1 The lens LGa (reference) reaches the drawing unit MU6. Figure 2 The diagram shows the states of the two beams LB6a and LB6b in the optical path. Figure 17 The vertical coordinate system XYZ in the drawing unit MU6 and the vertical coordinate system XtYtZt in the drawing unit MU6 are respectively set to the same as the vertical coordinate system XtYtZt in the drawing unit MU6. Figures 1-6 as well as Figure 16 same. Figure 17 The optical path diagram observed in the XZ plane is such that the extension of the optical axis AX6, which is the center of the Y direction of the incident mirror IM6, is set to be the rotation axis LE6 (equivalent to the rotation center when the entire drawing unit MU6 is rotated slightly). Figure 2 LE1) is coaxial.

[0142] The two beams LB6a and LB6b (divergent beams) reflected in the -Z direction by the incident mirror IM6 are... Figure 17 The light appears to overlap in the direction perpendicular to the paper (Y direction), but is positioned symmetrically in the Y direction across the optical axis AX6 and incident on the optical path adjustment unit BV6. The optical path adjustment unit BV6 consists of mirrors M30, M31, and M32, which are tilted at 45 degrees within the XZ plane and at an angle of 45° + θu / 2 relative to the YZ plane (θu is referenced). Figure 1 The image rotator (hereinafter referred to as the rotator) consists of a reflector M33, lenses Gv1, Gv2, and Gv3 arranged at an angle. For example, as disclosed in Japanese Patent Application Publication No. 8-334698 and International Publication No. 2018 / 164087, the rotator IRD consists of two reflecting surfaces that intersect the optical axis AX6 and are arranged in a mountain shape in the direction of the optical axis, and a third reflecting surface that is arranged parallel to the optical axis AX6 and departs from the edge of the mountain shape of the two reflecting surfaces.

[0143] exist Figure 17 In the image, two beams LB6a and LB6b from the incident mirror IM6 are reflected at right angles by the reflecting mirror M30 in the +X direction and enter the lens Gv1. The front focal point of the lens Gv1 is set at the reflecting surface of the incident mirror IM6, i.e., the position of the beam waists of the beams LB6a and LB6b. Therefore, the beams LB6a and LB6b passing through the lens Gv1 are converted into parallel beams, but when viewed in the XY plane, they intersect at the rear focal point surface Pva of the lens Gv1. Surface Pva passes through... Figure 16 The relay system shown consists of a condenser lens 16B and a lens Gv1, and is optically conjugate with the acousto-optic modulation element AM6. Two beams LB6a and LB6b, which intersect at surface Pva, are reflected at right angles in the -Z direction by the reflector M31 and incident on the lens Gv2, whose front focal point is set at the position of surface Pva.

[0144] The two beams LB6a and LB6b passing through lens Gv2 are converted into convergent beams and, again passing through an optical path parallel to the optical axis AX6, are reflected at right angles in the -X direction by mirror M32. The two beams LB6a and LB6b converge at the plane Pvb, which is the rear focal point of lens Gv2, forming beam waists, and then diverge while incident on the rotator IRD. Plane Pvb, through a relay system based on lenses Gv1 and Gv2, is conjugate to the reflecting surface (or its vicinity) of the incident mirror IM6. Therefore, on plane Pvb, parallel to the YZ plane, the point beams (beam waist positions) of beams LB6a and LB6b are located symmetrically in the Y direction, separated by the optical axis AX6.

[0145] The rotator IRD is configured to rotate around the optical axis AX6 with its third reflecting surface, parallel to the optical axis AX6, tilted at 45° relative to both the XY and XZ planes. Consequently, the two incident light beams LB6a and LB6b, which are rotated 90° around the optical axis AX6 as a whole, exit the rotator IRD and enter the lens Gv3. Both beams LB6a and LB6b exiting the rotator IRD become divergent beams, but the principal ray (central ray) is parallel to the optical axis AX6. Furthermore, the front focal point of the lens Gv3, including the optical path length of the rotator IRD, is set at the position on plane Pvb. Therefore, the light beams LB6a and LB6b passing through the lens Gv3 are converted into parallel beams and tilted intersectingly within the XZ plane.

[0146] Beams LB6a and LB6b are reflected in the -Z direction by mirror M33, which is tilted at an angle (45° + θu / 2) relative to the YZ plane. After intersecting at the position of surface Pvc, which is tilted at an angle θu relative to the XY plane, they are incident on mirror M10 within the drawing unit MU6. Beams LB6a and LB6b (both parallel beams) reflected in the -Xt direction by mirror M10 are incident at an angle relative to the optical axis (optical axis AX6) of lens LGa within the XtZt plane, onto the components... Figure 2 The primary lens LGa of the beam expander is shown. The front focal point of the lens LGa is set at the position of the surface Pvc. Therefore, on the surface OPa of the rear focal point of the lens LGa, the points (beam waists) SP6a and SP6b of the beams LB6a and LB6b are formed at symmetrical positions in the Zt direction across the optical axis.

[0147] The surface OPa ultimately becomes conjugate with the imaging surface (the surface of the sheet substrate P) set by the fθ lens system FT and the second cylindrical lens CYb within the drawing unit MU6. Therefore, the point beams LB6a and LB6b projected from the drawing unit MU6 onto the sheet substrate P are each focused at a predetermined interval in the Xt direction (sub-scanning direction). For each of the other drawing units MU1 to MU5, this is also related to… Figure 17 Similarly, by providing optical path adjustment units BV1 to BV5, which include rotators IRD, the point beams of the two beams LBna and LBnb can be focused at a predetermined interval in the Xt direction (sub-scanning direction). Therefore, in this embodiment, a total of four laser sources are provided: two laser sources 10B1 and 10B2 for supplying the two beams LBna and LBnb to the even-numbered drawing units MU6, MU4, and MU2 respectively, and two laser sources 10A1 and 10A2 for supplying the two beams LBna and LBnb to the odd-numbered drawing units MU1, MU3, and MU5 respectively.

[0148] In this embodiment, as before Figure 4 , Figure 6 As shown, laser light sources 10A1 and 10B1 can also be arranged symmetrically about the center point PG, and laser light sources 10A2 and 10B2 can be arranged symmetrically about the center point PG. Furthermore, Figure 6The triangular mirror 33 and the detection unit 34 shown can also be divided into two groups: one group that receives beams from laser source 10A1 and laser source 10B1, and another group that receives beams from laser source 10A2 and laser source 10B2. Furthermore, when the point light on the sheet substrate P based on the beams LBna (n=1 to 6) projected from each depicting unit MUn (n=1 to 6) onto the sheet substrate P is designated as point light Spa, and the point light on the sheet substrate P based on the beams LBnb (n=1 to 6) is designated as point light SPb, it is preferable to be able to accurately monitor (measure) the positional changes of the two point lights Spa and SPb on the sheet substrate P.

[0149] Figure 18 This is a diagram illustrating an example of an optical path that guides the light beams from the four laser sources 10A1, 10A2, 10B1, and 10B2 used in this embodiment to the primary acousto-optic modulation elements AM6 and AM1. Figure 18 The vertical coordinate system XYZ is set to be the same as the previous one. Figure 4 Same, in addition, for and Figure 4 Components with identical configurations are labeled with the same reference numerals. Laser sources 10A1 and 10A2, arranged side-by-side in the Y direction, emit beams LSA1 and LSA2 (parallel beams) in the +X direction, respectively. Beam LSA1 is reflected obliquely in the +Y direction by mirror M40a, and beam LSA2 is reflected obliquely in the -Y direction by mirror M40b. Beams LSA1 and LSA2, reflected by mirror M40a and M40b respectively, are reflected at two reflecting surfaces of the V-shaped mirror M40c at a predetermined intersection angle within the XY plane.

[0150] The two beams LSA1 and LSA2 reflected by the V-shaped reflector M40c are as before. Figure 15C As explained, the light is incident on a prism block VP1, whose incident angle ±θya is adjusted to suit the primary acousto-optic modulator AM1. Two beams, LSA1 and LSA2 (parallel beams), emanating from the prism block VP1, propagate in the XY plane with a predetermined inclination relative to the optical axis AXa, intersecting within the crystal of the primary acousto-optic modulator AM1. Furthermore, in the optical path from the prism block VP1 to the primary acousto-optic modulator AM1, a half-wave plate WP1 capable of rotating around the optical axis AXa and a polarizing beam splitter PBS1 that reflects a portion of each of the two beams LSA1 and LSA2 as a measurement beam MBa' in the +Y direction are provided. The ratio of the transmitted intensity of the two beams LSA1 and LSA2 in the polarizing beam splitter PBS1 to the reflected intensity of the branched measurement beam MBa' can be adjusted by the rotation angle of the half-wave plate WP1.

[0151] The measuring beam MBa' (containing the intensity of a portion of each of the two beams LSA1 and LSA2) was previously... Figure 6 The triangular mirror 33 and detection unit 34 described herein receive and measure the relative variation of the beams LSA1 and LSA2. Furthermore, in order to correct for variations in the position and tilt of the beams LSA1 and LSA2 from their respective emission outlets of laser sources 10A1 and 10A2, the optical paths between laser source 10A1 and reflector M40a, and between laser source 10A2 and reflector M40b, are configured as described above. Figure 9 The correction optical system shown. Although in Figure 18 Not shown in the diagram, but in the optical path from the polarization beam splitter PBS1 to the detection unit 34, the following settings are configured as needed: Figure 4 The relay optical system formed by lenses GL1a, GL2a, etc. shown.

[0152] Two beams, LSB1 and LSB2, supplied to the even-numbered drawing units MU6, MU4, and MU2, are emitted from laser sources 10B1 and 10B2, respectively. Beam LSB1 from laser source 10B1 passes through mirror M42a (same as mirror M40a), V-shaped mirror M42c (same as V-shaped mirror M40c), and prism block VP2 (same as prism block VP1), and is inclined at a predetermined angle relative to the optical axis AXb in the XY plane before entering the primary acousto-optic modulation element AM6. Similarly, beam LSB2 from laser source 10B2 passes through mirror M42b (same as mirror M40b), V-shaped mirror M42c, and prism block VP2, and is also inclined at a predetermined angle relative to the optical axis AXb in the XY plane before entering the primary acousto-optic modulation element AM6.

[0153] A half-wave plate WP2 and a polarizing beam splitter PBS2 are arranged in the optical path between the prism block VP2 and the acousto-optic modulation element AM6, so that the measurement beam MBb' of a portion of each of the two beams LSB1 and LSB2 is received by the detection unit 34 via the triangular mirror 33. In this embodiment, the overall optical configuration of the laser light sources 10A1, 10A2, reflectors M40a, M40b, V-shaped reflector M40c, prism block VP1, half-wave plate WP1, and polarizing beam splitter PBS1 is point-symmetric with respect to the overall optical configuration of the laser light sources 10B1, 10B2, reflectors M42a, M42b, V-shaped reflector M42c, prism block VP2, half-wave plate WP2, and polarizing beam splitter PBS2 in the XY plane about the center point PG.

[0154] In the above Figure 18In this system, the optical system consisting of mirrors M40a and M40b, V-shaped mirror M40c, and prism block VP1 (or the optical system consisting of mirrors M42a and M42b, V-shaped mirror M42c, and prism block VP2) functions as a synthesizing optical system that combines two beams LSA1 and LSA2 (or LSB1 and LSB2) within the primary acousto-optic modulation element AM1 (or AM6) in a manner that intersects in the non-diffraction direction (Y direction) at a specified cross angle (for example, 0° < θy ≤ 1°).

[0155] In addition, in the previous Figure 4 The structure of the beam switching unit (BDU) is the same, but the optical path configuration of the measurement beam MBa' (MBa) from the laser source 10A to the triangular mirror 33 (or detection unit 34) and the optical path configuration of the measurement beam MBb' (MBb) from the laser source 10B to the triangular mirror 33 (or detection unit 34) do not necessarily have to be point-symmetric about the center point PG rotated 180°. They can also be line-symmetric in the XY plane. Specifically, they can be line-symmetric about a center line parallel to the X-axis perpendicular to the center point PG, or line-symmetric about a center line parallel to the Y-axis perpendicular to the center point PG.

[0156] Figure 19 It is shown schematically in Figures 16-18 The diagram shown illustrates the scanning of two point lights SPa and SPb projected onto the sheet-like substrate P in the second embodiment of the structure shown. Here, as an example, it represents the scanning based on the light source... Figure 17 The diagram shows the main scan of the point lights SPa and SPb of the two beams LB6a and LB6b projected by the depiction unit MU6. (Example:) Figure 17 As shown, when two beams LB6a and LB6b are incident on the drawing unit MU6, as... Figure 19 As shown, two point lights, SP1 and SP2, are located separately on the sheet-like substrate P along the Xt direction (sub-scanning direction) with a center interval ΔXS. Here, if the effective diameter of each point light, SP1 and SP2, is taken as 1 / e of the peak intensity value... 2If we define φs (μm) as the diameter of half the intensity value, then, as an example, the center spacing ΔXS is set to ΔXS ≥ 1.5·φs. However, to reduce the influence of various optical aberrations, the center spacing ΔXS can be reduced to ΔXS = 0.5·φs (where point beams SPa and SPb overlap each other with half the diameter φs). Conversely, when the center spacing ΔXS is more than 10 times the diameter φs, the shapes of point beams SPa and SPb are distorted due to the influence of various aberrations, and the telecentric error increases. Therefore, when α is set to an integer greater than or equal to 1, the center spacing ΔXS can be set as ΔXS ≥ 0.5·α·φs (α = 1, 2, 3, etc.) as a general formula.

[0157] When the laser sources 10B1 and 10B2 are fiber amplifier laser sources with an oscillation frequency of 400MHz, the point lights SPa and SPb are pulsed in response to a clock signal CLK with a period of 2.5ns in the Yt direction (Y direction), which is the main scanning direction. Therefore, the point lights SPa and SPb are set to overlap in the Yt direction with half the diameter φs. That is, the rotation speed of the polygon mirror PM is set so that the scanning speed Vss of the point lights SPa and SPb in the Yt direction is Vss = (φs / 2μm) / 2.5ns. Similarly, the moving speed of the sheet substrate P in the Xt direction is also set to overlap in the Xt direction with half the diameter φs of the point lights SPa or SPb. Therefore, when only a single point light SP is projected from the drawing unit MU6, the scanning of the point light SP on the sheet substrate P is as follows: Figure 19 As shown, the moving speed of the sheet substrate P is set in such a way that each of the drawing lines SL6a, SL6a', SL6b, SL6b', ..., SL6f, SL6f'... is formed in the Xt direction with a spacing of ΔXT (=φs / 2).

[0158] On the other hand, such as Figure 19 As shown, when two point lights, SP1 and SP2, are arranged in the Xt direction, SP1 and SP2 scan simultaneously in the main scanning direction through the rotation of the polygon mirror PM. Therefore, as Figure 19 As shown on the right, to make the point lights ultimately illuminating the sheet substrate P overlap in the Xt direction at intervals of φ / 2, it is only necessary to move the sheet substrate P so that the single-line tracing formed by the simultaneous scanning of the two point lights SPa and SPb becomes SL6a, SL6b, SL6c, ... Therefore, whether in the case of a single point light SP or two point lights SPa and SPb, if the rotation speed of the multifaceted mirror PM is not changed (keeping the scanning speed Vss the same), then in the case of... Figure 19With two point lights, SPb and SPb, the moving speed of the sheet substrate P in the Xt direction can be doubled, which means the exposure time of the sheet substrate P can be halved.

[0159] In this modified example, two beams LSA1, LSA2 (or LSB1, LSB2) from two laser light sources 10A1, 10A2 (or 10B1, 10B2) pass through the acousto-optic modulation element AMn within the beam switching unit BDU at a predetermined intersection angle. However, it is also possible to arrange three laser light sources with three beams intersecting at the position of the acousto-optic modulation element AMn. The third beam is set to be coaxial with the optical axis AXa or AXb of the primary acousto-optic modulation element AM1 or AM6 within the beam switching unit BDU. In this case, the third point light projected from each drawing unit MUn onto the sheet substrate P is set at... Figure 19 The two point lights SPa and SPb shown are positioned between each other. The three point lights are preferably configured to be positioned between each other... Figure 19 The three point lights do not overlap in the Xt direction, but the center interval ΔXS in the Xt direction of each of the three point lights can also be set as ΔXS = 0.5·φs (the point lights arranged in the Xt direction overlap by 1 / 2 of the diameter φs each time).

[0160] [Variation Example 2]

[0161] Figure 20 It is shown before Figure 2 A perspective view of a modified example of the depicting unit MUn (MU1~MU6). Figure 20 The structure of the depiction unit MUn is disclosed, for example, in International Publication No. 2019 / 082850, and will therefore be described simply, but... Figure 20 Among the components, for Figure 2 Components with the same function are labeled with the same numbers. Additionally, the vertical coordinate system XtYtZt is also set accordingly. Figure 2 Same as this variation. Figure 2 The main difference lies in the fact that an imaging system formed by lenses LGd and LGe is set in the optical path between the first cylindrical lens CYa and the polygon mirror PM, and three reflecting mirrors M14a, M14b, and M14c are set in the optical path from lens LGe to the polygon mirror PM to reflect the optical path. The imaging system composed of lenses LGd and LGe makes the position of the rear focal point of the first cylindrical lens CYa and the reflecting surface Rp1 of the polygon mirror PM form an imaging relationship.

[0162] exist Figure 20 In the depiction unit MUn, also as in Figures 16-18As explained, two laser beams LBna and LBnb are supplied from two laser sources 10A1 and 10A2 (or 10B1 and 10B2) via the incident mirrors IMn (n=1 to 6) and the optical path adjustment unit BVn (n=1 to 6) of the beam switching unit BDU, respectively. However, by using an imaging system based on lenses LGd and LGe within the drawing unit MUn and optical path bending based on three mirrors M14a, M14b, and M14c, the following is omitted. Figure 17 The rotating IRD is shown within the optical path adjustment section BVn (n = 1 to 6). Therefore, in Figure 17 In the depicted unit MU6, the two beams LB6a and LB6b (parallel beams) reflected by the mirror M10 and incident on the lens LGa are symmetrically tilted relative to the optical axis within a plane containing the optical axis of the lens LGa and parallel to the XtYt plane. Therefore, formed in Figure 17 Points (beam waists) SP6a and SP6b of the surface OPa shown are located on lines that intersect the optical axis and extend along the Yt direction (Y direction).

[0163] When using the depiction unit MUn (n = 1 to 6) of the above variation example 2, as follows Figure 19 As shown, two spot lights, SPb and SPb, can also be arranged in the Xt direction with a certain center interval ΔXS, thus reducing the exposure processing time of the sheet substrate P to half the exposure processing time of a single spot light SP. Furthermore, Figure 20 The photoelectric sensor DT is positioned at a position optically conjugate with the two point lights SPa and SPb projected onto the sheet substrate P. Therefore, it is composed of two segmented photoelectric elements that respectively receive the reflected light from the sheet substrate P generated by the projection of the point light SPa and the reflected light from the sheet substrate P generated by the projection of the point light SPb.

[0164] [Variation Example 3]

[0165] In the first and second embodiments described above, a point-scanning drawing unit MUn (n = 1 to 6) is used, in which the intensity of point light SP (or SPa, SPb) projected onto the sheet-like substrate P, which is the irradiated surface, is modulated in response to drawing data while performing one-dimensional scanning. However, the structure of the drawing unit MUn can also be a maskless exposure method in which a variable light intensity distribution generated by the reflected light from a digital micromirror device (DMD) or a spatial light modulator (SLM) is projected onto the sheet-like substrate P through a projection imaging system.

[0166] In this case, a drawing unit is composed of one DMD (or SLM) and one projection imaging system, and multiple drawing units are arranged in the width direction (Y direction) of the sheet substrate P. As a light source device that supplies exposure beams (illumination beams to the DMD and SLM) to the multiple drawing units respectively, when using multiple laser light sources, previous methods can be used. Figure 6 The detection unit 34 shown accurately monitors (measures) the changes in the beams emitted from each laser source.

[0167] [Variation Example 4]

[0168] Figure 21 It is the previous Figure 17 The diagram shown is a three-dimensional representation of a portion of the optical path adjustment unit BV6 after structural deformation. The vertical coordinate system XYZ is set to be aligned with... Figure 17 as well as Figure 16 Same. For example, in Figure 16 As explained, two beams, LSa and LSb (parallel beams), are incident on the acousto-optic modulator AM6 at a certain angle, separated by the optical axis AXb in the XY plane. When the acousto-optic modulator AM6 is in the ON state, the first-order diffracted beams LSa1 and LSb1 of LSa and LSb are focused by the condenser lens 16B at the reflecting surface of the reflection mirror IM6 (tilted 45 degrees from the plane parallel to the XY plane) to form the beam waist. The two first-order diffracted beams LSa1 and LSb1, reflected in the -Z direction by the reflecting surface of the reflection mirror IM6, are incident on the reflecting mirror M30a as beams LB6a and LB6b, respectively.

[0169] The reflecting surface of mirror M30a is configured to be tilted at 45 degrees from a surface parallel to the XY plane, reflecting beams LB6a and LB6b in the -X direction. The beams LB6a and LB6b reflected by mirror M30a are then reflected in the -Y direction by mirror M30b, which has a reflecting surface tilted at 45 degrees from a surface parallel to the XY plane, and further reflected in the -Z direction by mirror M30c, whose reflecting surface is tilted at 45 degrees from a surface parallel to the XY plane. The two beams LB6a and LB6b reflected by mirror M30c are incident on... Figure 17 The lens Gv1 is shown. The principal rays (central rays) of the light beams LB6a and LB6b, respectively, are parallel to the optical axis AX6 of lens Gv1 and are located symmetrically across the optical axis AX6 in the optical path from the reflecting mirror IM6 through the reflecting mirrors M30a, M30b, and M30c. Furthermore, the front focal point of lens Gv1 is set at the reflecting surface of the reflecting mirror IM6 via the optical path of the reflecting mirrors M30a, M30b, and M30c.

[0170] like Figure 21As shown, by setting reflectors M30a, M30b, and M30c after the incident mirror IM6, the central rays of the two beams LB6a and LB6b (divergent beams) move away from the incident position of lens Gv1 in the Y direction at a position separated from the optical axis AX6. Figure 21 The reflectors M30a, M30b, and M30c have the same characteristics as... Figure 17 The image rotator IRD inside the optical path adjustment unit BV6 shown has the same function. Similarly, the two beams LBna and LBnb (n=1-5) reflected in the -Z direction by the other incident mirrors IM1-IM5 are also similarly... Figure 21 The reflectors M30a, M30b, and M30c are incident on the lens Gv1 contained in the optical path adjustment section BVn (n = 1 to 5).

[0171] When using this variation, by Figure 17 The optical path adjustment section BVn (n = 1 to 6) with the rotator IRD removed is shown. Figure 20 The depiction unit MUn (n = 1 to 6) shown is capable of [description of the unit MUn]. Figure 19 As shown, the two point lights SPa and SPb are arranged with a center interval ΔXS separated in the Xt direction, and a main scan is performed along the drawing line SLn (n = 1 to 6). According to this modified example, by Figure 17 The lenses Gv1~Gv3 and the mirrors M31~M33 shown are... Figure 21 The reflectors M30a, M30b, and M30c constitute the optical path adjustment section BVn (n = 1 to 6).

[0172] [Variation Example 5]

[0173] As before Figure 4 , Figure 5 As shown, beam splitters 30A and 30B, which branch a portion of the light quantity (energy) of the beams LBa and LBb from each laser source 10A and 10B into measurement beams MBa and MBb, can also be polarization beam splitters (equivalent to...). Figure 18 (as described in the text, PBS1 and PBS2). In this case, in Figure 4 (or Figure 5 A rotatable half-wavelength plate (equivalent to) is provided between the laser source 10A and the beam splitter 30A, and between the laser source 10B and the beam splitter 30B. Figure 18(WP1, WP2 as described in the text). By adjusting the rotation angle of the half-wave plate, the light intensity ratio of the exposure beam LBa (LBb) transmitted through the beam splitter 30A (30B) to the measurement beam MBa (MBb) reflected by the beam splitter 30A (30B) can be adjusted. Therefore, by individually adjusting the rotation angle of each half-wave plate on the laser source 10A side and the half-wave plate on the laser source 10B side, it is also possible to adjust the intensity of the point light SP projected from each of the odd-numbered drawing units MU1, MU3, MU5 onto the sheet substrate P to be consistent with the intensity of the point light SP projected from each of the even-numbered drawing units MU2, MU4, MU6 onto the sheet substrate P.

[0174] [Variation Example 6]

[0175] In the previous Figures 1-6 In the first embodiment shown, a laser source (first light source device) 10A supplying an exposure beam LBa is provided for the three odd-numbered drawing units MU1, MU3, and MU5, and a laser source (second light source device) 10B supplying an exposure beam LBb is provided for the three even-numbered drawing units MU2, MU4, and MU6. However, in a pattern drawing apparatus (exposure apparatus) that sequentially exposes patterns drawn by two drawing units, even with a device structure where one laser source (light source device) is provided for each of the two drawing units, the same detection unit 34 can be provided. Furthermore, in the case of providing four groups of three drawing units supplied with beams from one laser source (light source device), and performing continuous exposure in a total of 12 drawing units MU1 to MU12, four laser sources are provided. In this case, the optical paths of the measurement beams MBa, MBb, MBc, and MBd generated by branches from the beams LBa, LBb, LBc, and LBd of each of the four laser sources are, for example, as shown below. Figure 22 That's how it's set up.

[0176] Figure 22 This diagram schematically illustrates the optical paths of the measurement beams MBa, MBb, MBc, and MBd generated by branches of the beams LBa, LBb, LBc, and LBd from four laser sources 10A, 10B, 10C, and 10D, respectively. Figure 22 In this example, the X-direction of the vertical coordinate system XYZ is the sub-scanning direction for the movement of the sheet substrate P, and the Y-direction is the main scanning direction for the point light projected from the 12 drawing units MU1 to MU12. In this modified example, the beam LBa emitted from the emission port of the laser source 10A in the +X direction passes through beam splitters 30A, 12A, etc., in series. Figure 4The odd-numbered acousto-optic modulation elements AM1, AM3, and AM5 are oriented as shown and supplied to the odd-numbered drawing units MU1, MU3, and MU5. Furthermore, in this modified example, the laser source 10B is arranged back-to-back with the laser source 10A in the X direction. The beam LBb emitted from the emission outlet of the laser source 10B in the -X direction is passed through beam splitters 30B, 12B, etc., in series. Figure 4 The even-numbered acousto-optic modulation elements AM2, AM4, and AM6 are oriented in a specific manner and supplied to the even-numbered drawing units MU2, MU4, and MU6.

[0177] Figure 22 The center point PG shown is Figure 4 Similarly, the center point PG represents the center point of point symmetry of the arrangement of the 12 drawing units MU1 to MU12 in the XY plane. The remaining two laser light sources 10C and 10D are arranged in a point symmetric relationship such that the arrangement of the two laser light sources 10A and 10B is rotated 180° around the center point PG. In addition, the two laser light sources 10A and 10B and the two laser light sources 10C and 10D are also arranged symmetrically in the XY plane about a center line set parallel to the X-axis and passing through the center point PG.

[0178] The light beam LBc emitted from the emission outlet of laser source 10C in the +X direction is directed through beam splitters 30C, 12C, etc., in series through odd-numbered acousto-optic modulation elements AM11, AM9, AM7, and supplied to odd-numbered drawing units MU11, MU9, MU7. The light beam LBd emitted from the emission outlet of laser source 10D, which is arranged back-to-back with laser source 10C in the X direction, in the -X direction is directed through beam splitters 30D, 12D, etc., in series through even-numbered acousto-optic modulation elements AM12, AM10, AM8, and supplied to even-numbered drawing units MU12, MU10, MU8.

[0179] The beam LBa from laser source 10A is split by beam splitter 30A into a measurement beam MBa, which is then transmitted via mirror 31A and a relay optical system (not shown). Figure 4The beam LBb from laser source 10B is branched by beam splitter 30B into a measurement beam MBb, which is then directed towards the triangular mirror 33' positioned at center point PG via mirror 31B and a relay optical system (not shown). Similarly, the beam LBc from laser source 10C is branched by beam splitter 30C into a measurement beam MBc, which is then directed towards the triangular mirror 33' positioned at center point PG via mirror 31C and a relay optical system (not shown). Likewise, the beam LBd from laser source 10D is branched by beam splitter 30D into a measurement beam MBd, which is then directed towards the triangular mirror 33' positioned at center point PG via mirror 31D and a relay optical system (not shown).

[0180] Figure 23 This is a perspective view showing the configuration relationship between the triangular mirror 33' and the detection unit 34 constituting the variable optical detection system, with the vertical coordinate system XYZ and... Figure 22 The settings are the same as in [the previous section]. For example... Figure 22 As shown, the four measuring light beams MBa, MBb, MBc, and MBd directed toward the triangular mirror 33' are configured to form optical paths parallel to the Y-axis. The triangular mirror 33' has two reflecting surfaces 33a' and 33b' tilted at 45° from the XY plane with their edges parallel to the X-axis. The two measuring light beams MBa and MBb, advancing in the +Y direction, are reflected in the +Z direction by the reflecting surface 33a' of the triangular mirror 33', and incident on the plane parallel to the optical axis AXu. Figure 6 Similarly, the lens 34A of the detection unit 34 is also constructed in this manner. Similarly, the two measuring light beams MBc and MBd that are moving in the -Y direction are reflected in the +Z direction by the reflecting surface 33b' of the triangular mirror 33', and are incident on the lens 34A of the detection unit 34 in a state parallel to the optical axis AXu.

[0181] Figure 23 The detection unit 34 is also with Figure 6 Similarly, the device includes a lens 34B, a beam splitter (semi-transparent mirror) 34E, a first imaging element 34C, and a second imaging element 34G. When the imaging surface of the imaging element 34C is divided into four quadrants, measurement light beams MBa, MBb, MBc, and MBd are projected into each quadrant. Furthermore, each of the four measurement light beams MBa, MBb, MBc, and MBd has a focusing point approximately at the center of the imaging surface of the imaging element 34G. Therefore, when the imaging element 34G performs variable measurements, image information can be captured at the timing of any one of the four measurement light beams MBa, MBb, MBc, and MBd, i.e., at the timing of any one of the four laser light sources 10A, 10B, 10C, and 10D oscillating beams.

[0182] As in this modified example, even when using a pattern exposure apparatus with four laser light sources (light source devices) 10A, 10B, 10C, and 10D, the configuration and path length of the optical components (mirrors, lenses) forming the optical paths of the measurement light beams MBa, MBb, MBc, and MBd from each laser light source to the triangular mirror 33' (variation detection optical unit) can be set to be the same. Furthermore, as... Figure 22 As shown, when observing the optical path of each of the measurement beams MBa, MBb, MBc, and MBd in the XY plane, a symmetrical relationship can be set about the center point PG or about a line parallel to the Y-axis or X-axis passing through the center point PG. Therefore, the measurement sensitivity and accuracy can be made the same when measuring the variations of the beams LBa, LBb, LBc, and LBd emitted from the four laser sources 10A, 10B, 10C, and 10D, respectively. Thus, the relative displacement and tilt variations of the four beams LBa, LBb, LBc, and LBd can be accurately captured.

[0183] In addition, Figure 22 The example illustrates a structure in which one laser source supplies a beam to three drawing units, but it is not limited to this. It can also be a pattern exposure device with multiple (two or more) laser sources (source devices) that distribute the emitted beam to two or more drawing units according to the distribution of each laser source.

Claims

1. A pattern exposure apparatus, comprising: The first drawing unit draws a pattern on a substrate using a first light beam from a first light source device; and The second drawing unit draws a pattern on the substrate using a second light beam from a second light source device. in, The pattern exposure device has: A first light splitter is disposed in the optical path of the first light beam from the first light source device to the first drawing unit, and splits a portion of the first light beam into a first measuring light beam; A second light splitter is disposed in the optical path of the second beam from the second light source device to the second drawing unit, and splits a portion of the second beam into a second measuring beam; A change detection optical unit receives the first measuring beam and the second measuring beam, and detects the relative positional change or relative tilting change of the first beam and the second beam. The first light guiding system forms an optical path from the first light splitter to the variation detection optical unit based on the first measuring beam; A second light guiding system, which forms an optical path from the second light splitter to the variation detection optical unit based on the second measurement beam; and A correction optical system is provided to correct for the relative positional or tilting changes of the first beam and the second beam detected by the variation detection optical unit.

2. The pattern exposure apparatus according to claim 1, wherein, The first light guide system and the second light guide system are configured to be point-symmetric or line-symmetric with respect to the change detection optical unit.

3. The pattern exposure apparatus according to claim 1 or 2, wherein, The change detection optical unit includes: A detection lens system, wherein a first measuring beam from the first light guide system and a second measuring beam from the second light guide system are incident on the detection lens system; and The imaging element is capable of receiving the first measuring beam and the second measuring beam that have passed through the detection lens system.

4. The pattern exposure apparatus according to claim 3, wherein, The first light guiding system and the second light guiding system each include a plurality of reflectors that guide the first measuring beam and the second measuring beam into the detection lens system in a manner parallel to the optical axis of the detection lens system.

5. The pattern exposure apparatus according to claim 3, wherein, The first light guiding system includes a relay optical system that forms a first surface optically conjugate to the emission outlet optically of the first light beam from the first light source device. The second light guiding system includes a relay optical system that forms a second surface optically conjugate with the emission outlet optically of the second beam from the second light source device. The detection lens system of the variation detection optical unit forms the conjugate surfaces of the first surface and the second surface on the same imaging surface.

6. The pattern exposure apparatus according to claim 5, wherein, The imaging element includes a first imaging element disposed on the imaging surface formed by the detection lens system and detecting changes in the lateral displacement of the first beam at the emission outlet of the first light source device and changes in the lateral displacement of the second beam at the emission outlet of the second light source device.

7. The pattern exposure apparatus according to claim 5 or 6, wherein, The imaging element includes a second imaging element configured to receive a focal point formed by the first measuring beam and the second measuring beam at the pupil plane of the detection lens system, and to detect tilt variations of the first beam at the emission outlet of the first light source device and tilt variations of the second beam at the emission outlet of the second light source device.

8. The pattern exposure apparatus according to claim 5 or 6, wherein, The detection lens system is a reduction relay optical system that images the first surface and the second surface at a predetermined reduction magnification onto the telecentric of the imaging surface.

9. The pattern exposure apparatus according to claim 1 or 2, wherein, The optical path length from the outlet of the first beam of the first light source device, through the first light splitter and the first light guide system, to the variation detection optical unit is set to be the same as the optical path length from the outlet of the second beam of the second light source device, through the second light splitter and the second light guide system, to the variation detection optical unit.

10. A pattern exposure apparatus, comprising: The first light source device emits the first beam of light; A second light source device that emits a second beam of light; Multiple acousto-optic modulation elements, which allow the first beam and the second beam to pass through in series; Multiple drawing units use the diffracted beams of the first beam and the second beam generated by the multiple acousto-optic modulation elements as point beams, and perform one-dimensional scanning of the point beams to draw a pattern on a substrate; a synthesizing optical system combines the first beam from the first light source device and the second beam from the second light source device within the primary acousto-optic modulation element of the multiple acousto-optic modulation elements in such a way that the first beam and the second beam pass through at a predetermined intersection angle in a non-diffraction direction perpendicular to the diffraction direction that generated the diffracted beams; A variation detection optical unit receives a portion of the synthesized first beam and second beam as a measurement beam, and detects the relative positional variation or relative tilt variation of the first beam and the second beam; and A correction optical system is provided to correct for the relative positional or tilting changes of the first beam and the second beam detected by the variation detection optical unit.

11. The pattern exposure apparatus according to claim 10, wherein, Each of the plurality of depiction units has a rotating polygonal mirror that deflects the diffracted beam. The one-dimensional scan is performed by turning the diffracted beam, which is deflected by the rotating multifaceted mirror, into a light spot.

12. The pattern exposure apparatus according to claim 10 or 11, wherein, The pattern exposure apparatus has a relay optical system in which the plurality of acousto-optic modulation elements are arranged in an optical path between the acousto-optic modulation elements in such a way that they are optically conjugate.

13. The pattern exposure apparatus according to claim 10 or 11, wherein, When the one-dimensional scan is used as the main scan, a secondary scan of the point light is performed in a direction perpendicular to the direction of the main scan. The cross angle between the first beam and the second beam based on the synthetic optical system is set such that the first point light generated by the first beam projected from the plurality of drawing units onto the substrate and the second point light generated by the second beam are separated by a center interval ΔXS in the direction of the sub-scanning.

14. The pattern exposure apparatus according to claim 13, wherein, The effective diameters of the first point light and the second point light are set as follows: At time s, the center interval ΔXS is set to satisfy ΔXS≥0.5·α· The relationship of s, where α is an integer greater than or equal to 1.

15. The pattern exposure apparatus according to claim 13, wherein, The sub-scanning is performed by moving the substrate relative to the plurality of drawing units.

16. The pattern exposure apparatus according to claim 15, wherein, The pattern exposure apparatus has a rotating cylinder that moves the substrate in the direction of the sub-scan.

Images