Light irradiation device and light irradiation method

Abstract

The present application provides a kind of light irradiation device and light irradiation method, can inhibit the decrease of detection precision caused by irradiation light.Light irradiation device has: stage, at least a part is made of transparent material;And at least one light irradiation part, for irradiating light to the upper surface of stage, be provided with the light transmission part for making light transmission and at least one scattering part for making light scattering on stage, light irradiation device further has: detection part, for detecting at least one of light transmission part and scattering part at least one of the light that is transmitted and the light that is scattered;And determination part, determines the position of at least one of light transmission part and scattering part based on the light quantity of detected light.

Description

Technical Field

[0001] The technology disclosed in this specification relates to techniques for detecting irradiated light. Background Technology

[0002] Previously, optical processing techniques were used to process objects by irradiating them with light, such as lasers (see, for example, Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2006-272430 Summary of the Invention

[0004] The problem the invention aims to solve

[0005] In order to improve the processing accuracy in the above-mentioned optical processing technology, it is important to control the position of the light irradiation with high precision.

[0006] One method for detecting the location of light illumination is to use a zone camera to capture images of the light. However, due to the accumulation of damage in components or optical elements located at the illuminated area, especially when detecting high-intensity light such as lasers, there is a problem of reduced detection accuracy.

[0007] The technology disclosed in this specification was developed in view of the problems described above, and is a technology for suppressing the reduction in detection accuracy caused by illumination light.

[0008] Technical solutions for solving the problem

[0009] The light irradiation apparatus of the first aspect of the technology disclosed in this specification includes: a stage, at least a portion of which is made of a transparent material; and at least one light irradiation part for irradiating light onto the upper surface of the stage, wherein the stage is provided with a light-transmitting part for allowing the light to pass through and at least one scattering part for scattering the light, the light irradiation apparatus further including: a detection part for detecting at least one of the light transmitted through the light-transmitting part and the light scattered by the scattering part; and a determination part for determining the position of at least one of the light-transmitting part and the scattering part based on the amount of light detected.

[0010] The light irradiation device of the second aspect of the technology disclosed in this specification is associated with the light irradiation device of the first aspect, wherein the determining unit determines the position of the boundary between the light-transmitting part and the scattering part based on the difference in the amount of light detected.

[0011] The light irradiation device of the third aspect of the technology disclosed in this specification is associated with the light irradiation device of the first or second aspect, and when viewed from above the stage, the scattering part is in the shape of a butterfly with one vertex of two triangles connected to each other.

[0012] The light irradiation device of the fourth aspect of the technology disclosed in this specification is associated with the light irradiation device of any one of the first to third aspects, wherein the light irradiated from the light irradiation unit is a laser.

[0013] The light irradiation device of the fifth aspect of the technology disclosed in this specification is associated with the light irradiation device of any one of the first to fourth aspects, wherein the detection unit includes a converging lens for converging at least one of the light transmitted through the light-transmitting part and the light scattered in the scattering part.

[0014] The light irradiation device of the sixth aspect of the technology disclosed in this specification is associated with the light irradiation device of the fifth aspect. The light irradiation device further includes a cavity in which the stage is housed. The cavity is in a vacuum or depressurized gas environment. The detection unit further includes: an optical fiber for transmitting the light focused by the converging lens to the outside of the cavity; and a photodetector disposed outside the cavity for detecting the light transmitted by the optical fiber.

[0015] The seventh aspect of the light irradiation method disclosed in this specification includes a step of irradiating light onto the upper surface of a stage made of a transparent material, wherein the stage is provided with a light-transmitting portion for transmitting the light and at least one scattering portion for scattering the light, the light irradiation method further includes a step of detecting at least one of the light transmitted through the light-transmitting portion and the light scattered by the scattering portion; and a step of determining the position of at least one of the light-transmitting portion and the scattering portion based on the amount of light detected.

[0016] Invention Effects

[0017] According to at least the first and seventh aspects of the technology disclosed in this specification, the scattering part irradiated by light is made of a transparent material, thus reducing damage to the irradiated part even when irradiated with high-intensity light such as laser light. Therefore, the positional accuracy of the light detected by the detection unit is less likely to decrease.

[0018] Furthermore, the objects, features, aspects, and advantages related to the technology disclosed in this specification will become clearer through the detailed description and accompanying drawings shown below. Attached Figure Description

[0019] Figure 1 This is a perspective view that schematically illustrates an example of the structure of a light irradiation device according to an embodiment.

[0020] Figure 2 This is a cross-sectional view showing an example of the internal structure and surrounding structure of the vacuum cavity of the light irradiation device according to an embodiment.

[0021] Figure 3 It is mainly shown Figure 2 A three-dimensional view of the light irradiation section and the stage in the illustrated structure.

[0022] Figure 4 It is mainly shown Figure 2 A cross-sectional view of an example of the structure of the light irradiation section and the stage in the illustrated structure.

[0023] Figure 5 This is a schematic diagram showing the structure and function of the convergent unit.

[0024] Figure 6 This is a schematic diagram showing the structure and function of the convergent unit.

[0025] Figure 7 This is a top view showing an example of the shape of the scattering part.

[0026] Figure 8 This shows scanning along the X-axis. Figure 7 A diagram illustrating an example of the detection signal obtained from a photodetector in the case of a scattering portion with an illustrative shape.

[0027] Figure 9 This is a cross-sectional view showing an example of a structure with multiple light-illuminating parts.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1: Light irradiation device

[0030] 18: Light irradiation part

[0031] 18B: Converging Lens

[0032] 18C: Laser

[0033] 42: Stage

[0034] 62: Testing Department

[0035] 62B: Fiber optic cable

[0036] 62C: Photodetector

[0037] 118: Light irradiation part

[0038] 118B: Converging Lens

[0039] 118C: Laser

[0040] 142: Light-transmitting section

[0041] 142A: Scattering section

[0042] 142B: Scattering section

[0043] 142C: Scattering part

[0044] 142D: Scattering section

[0045] 162: Converging Lens

[0046] 218: Light irradiation part

[0047] 218B: Converging Lens

[0048] 218C: Laser Detailed Implementation

[0049] Hereinafter, embodiments will be described with reference to the accompanying drawings. In the following embodiments, detailed features are shown for illustrative purposes, but these are examples, and not all features are necessarily necessary for implementing the embodiments.

[0050] Furthermore, the accompanying drawings are schematic representations, and structures have been appropriately omitted or simplified for ease of explanation. Additionally, the relationships between the sizes and positions of structures shown in different drawings may not be accurately depicted and can be appropriately modified. Moreover, even in non-sectional views such as top views, shading is sometimes added to facilitate understanding of the embodiments.

[0051] Furthermore, in the following description, the same structural components are illustrated using the same reference numerals, and they have the same names and functions. Therefore, detailed descriptions of them are sometimes omitted to avoid repetition.

[0052] Furthermore, in the descriptions contained herein, the use of terms such as "possessing," "including," or "having" a certain structural member is not an exclusive statement excluding the existence of other structural members, unless otherwise stated.

[0053] Furthermore, even though ordinal numbers such as "first" or "second" are sometimes used in the descriptions contained herein, these terms are used to facilitate understanding of the implementation methods and are not limited to the order generated by these ordinal numbers.

[0054] Furthermore, in the descriptions contained in this specification, the terms "positive direction of the ... axis" or "negative direction of the ... axis" refer to the direction along the arrow of the ... axis shown in the illustration as the positive direction, and the direction opposite to the arrow of the ... axis shown in the illustration as the negative direction.

[0055] Furthermore, expressions indicating relative or absolute positional relationships in the descriptions contained herein, such as “in one direction,” “along a direction,” “parallel,” “orthogonal,” “center,” “concentric,” or “coaxial,” unless otherwise stated, include cases where the positional relationship is strictly expressed and cases where angular or distance displacement occurs within the range where tolerances or equivalent functionality can be obtained.

[0056] Furthermore, in the descriptions contained herein, even though terms indicating specific positions or directions such as "upper," "lower," "left," "right," "side," "bottom," "top," or "inside" are sometimes used, these terms are used for the purpose of easily understanding the contents of the embodiments and are unrelated to the actual position or direction during implementation.

[0057] <Implementation Method>

[0058] The light irradiation apparatus of this embodiment will now be described. Furthermore, in the following embodiments, a light irradiation apparatus with a vacuum or depressurized gas environment inside the cavity is described as an example, but it is also applicable when the cavity is not a vacuum.

[0059] <Structure of the light irradiation device>

[0060] Figure 1 This is a perspective view schematically showing an example of the structure of the light irradiation device 1 of this embodiment. Figure 1 For simplicity, the cavity frame supporting the vacuum cavity 12 or the actual wiring connections are omitted in the illustration. Furthermore, to prevent degradation of the substrate W's properties, the "vacuum" in this embodiment is preferably a high vacuum (e.g., 0.00001 Pa), but this also includes cases where the vacuum level does not reach this high vacuum.

[0061] like Figure 1 As illustrated, the light irradiation device 1 includes: a vacuum chamber 12; an external fixing part 14 such as a stone platform; a bellows 16, which serves as a telescopic member, connecting the vacuum chamber 12 to the external fixing part 14, and is made of, for example, stainless steel; a light irradiation part 18 that irradiates light into the vacuum chamber 12; a vacuum pump 21 that depressurizes the vacuum chamber 12 to create a vacuum state; and a control part 22 that controls each drive part of the light irradiation device 1. In the above description, a bellows made of stainless steel is shown as an example of a telescopic member, but depending on the required specifications, a telescopic member made of a metal other than stainless steel, or a telescopic member made of resin, may also be used. Furthermore, the shape of the telescopic member does not have to be a bellows shape like the bellows 16A described above.

[0062] The vacuum cavity 12 has a space inside to accommodate the substrate W. The substrate to be processed includes, for example, semiconductor wafers, glass substrates for liquid crystal display devices, substrates for flat panel displays (FPDs) such as organic EL (electroluminescence) display devices, substrates for optical discs, substrates for magnetic disks, substrates for optical disc drives, glass substrates for photomasks, ceramic substrates, substrates for field emission displays (FEDs), or substrates for solar cells. Furthermore, the substrate W is, for example, a substrate with a thin film formed on its upper surface.

[0063] Additionally, an opening 12A is formed on the side of the vacuum chamber 12 for the substrate W to pass through during loading and unloading. When the vacuum chamber 12 becomes a vacuum, the opening 12A is appropriately closed. Other structures housed inside the vacuum chamber 12 will be described later.

[0064] The light irradiation unit 18 irradiates light onto the upper surface of the substrate W housed within the vacuum chamber 12. At this time, the substrate W is pre-aligned by the detection unit 62 (described later). The light irradiation unit 18 performs an ablation process on the substrate W, for example, by irradiating it with a laser. Alternatively, the light irradiation unit 18 may be a component that irradiates light, such as electron beams, for processing purposes. The light irradiation unit 18 irradiates light from outside the vacuum chamber 12 onto the upper surface of the substrate W housed within the vacuum chamber 12 via an irradiation window (not shown) (a transparent plate made of quartz or the like). Then, by moving the substrate W within the vacuum chamber 12 relative to the light irradiation unit 18 or by controlling the optical system in the light irradiation unit 18, the upper surface of the substrate W is scanned by light. Furthermore, the light irradiation unit 18 is disposed on the upper surface of a stage 24 fixed to the external fixing unit 14.

[0065] The control unit 22 may include: a storage device including a memory (storage medium), such as a hard disk drive (HDD), random access memory (RAM), read-only memory (ROM), flash memory, volatile or non-volatile semiconductor memory, a magnetic disk, a floppy disk, an optical disk, a compact disk, a mini disk, or a DVD; a processing circuit of a central processing unit (CPU) that executes programs stored in, for example, the storage device, an external CD-ROM, an external DVD-ROM, or an external flash memory; an input device capable of inputting information, such as a mouse, a keyboard, a touch panel, or various switches; and an output device capable of outputting information, such as a display, a liquid crystal display device, or a lamp.

[0066] The control unit 22 controls the output of the light source in the light irradiation unit 18 and the direction of light irradiation, or controls the output of the vacuum pump 21, and further controls the drive of each drive unit (e.g., the drive unit of the linear motor mechanism or the drive unit of the lifting pin mechanism) as described later. Furthermore, as described later, the control unit 22 can determine the position of the stage on which the substrate W is placed based on the detected value of the light irradiated from the light irradiation unit 18.

[0067] Figure 2 This is a cross-sectional view showing an example of the internal structure and surrounding structure of the vacuum cavity 12 of the light irradiation device 1 according to this embodiment. (Example:) Figure 2 As illustrated, the vacuum chamber 12 includes: a stage 42 with a substrate W disposed on its upper surface; a slider 44 movable along the Y-axis and supporting the stage 42 from below; a base 46 independently fixed to the external fixing part 14; a linear guide 48 fixed to the base 46 and extending along the Y-axis; a linear motor mechanism 50 that moves the slider 44 along the linear guide 48 in the Y-axis direction; a lifting pin mechanism 52 having a lifting pin 52A that passes through a through hole (not shown) formed in the stage 42 and supports the substrate W; and a detection part 62 disposed below the stage 42. Figure 2 (The negative Z-axis side).

[0068] The stage 42 holds the substrate W with its processing surface facing upwards and maintains the substrate W approximately horizontal. The detailed structure of the stage 42 will be described later. The slider 44 supporting the stage 42 moves along the Y-axis via a linear motor mechanism 50. Furthermore, light irradiated from the light irradiation unit 18 scans along the X-axis, thereby allowing the entire surface of the processing area of ​​the substrate W to be scanned by light when viewed from above. Alternatively, light irradiated from the light irradiation unit 18 scans along both the X-axis and Y-axis, thereby allowing the entire surface of the processing area of ​​the substrate W to be scanned by light when viewed from above. Additionally, the lifting pin mechanism 52 is fixed to the base 46.

[0069] The linear motor mechanism 50 is fixed to the external fixing part 14 located on the side of the vacuum chamber 12 via an opening 12B formed on the side of the vacuum chamber 12. Specifically, the linear motor mechanism 50 is fixed to the end of a hollow columnar member 14A that passes through a bellows 16A welded to the opening 12B. At this time, wiring and the like connected to the linear motor mechanism 50 are led out to the outside of the vacuum chamber 12 through the interior of the columnar member 14A. Furthermore, the columnar member 14A included in the external fixing part 14 is fixed to the external member 14B included in the external fixing part 14. In addition, the columnar member 14A does not contact the bellows 16A connected to the side of the vacuum chamber 12.

[0070] The base 46 is fixed to the external fixing part 14 located below the vacuum chamber 12 via an opening 12C formed in the bottom surface of the vacuum chamber 12. Specifically, the base 46 is fixed to the end of a columnar member 14C that passes through a bellows 16B welded to the opening 12C. Furthermore, the columnar member 14C included in the external fixing part 14 is fixed to the external member 14B included in the external fixing part 14. In addition, the columnar member 14C does not contact the bellows 16B connected to the bottom surface of the vacuum chamber 12.

[0071] exist Figure 2 In this configuration, external fixing parts 14 are arranged all over the sides and bottom of the vacuum chamber 12. The external fixing parts 14 at these locations may not be continuous, but may be distributed in these locations, or may be arranged at any location. In addition, the vacuum chamber 12 is supported and fixed from the bottom vertically by a cavity frame (not shown) separately from the bellows 16B, but the cavity frame is arranged independently of the external fixing parts 14.

[0072] The detection unit 62 is located below the stage 42 and can detect light emitted from the light irradiation unit 18. The detailed structure of the detection unit 62 will be described later.

[0073] Figure 3 It is mainly shown Figure 2 A perspective view of the light irradiation unit 18 and the stage 42 in the illustrated structure. Figure 3 The image shows a state where a substrate W is disposed on the upper surface of the stage 42. The light irradiation unit 18 can direct the light irradiation direction along... Figure 3 The X-axis scanning in the middle can be performed by the stage 42 via the linear motor mechanism 50 (see reference). Figure 2 It moves along the Y-axis. As a result, the light irradiating from the light irradiation unit 18 onto the upper surface of the stage 42 can form a rectangular irradiation area (light irradiation area) on the upper surface of the substrate W.

[0074] like Figure 3 As shown, the stage 42 includes: an object placement area 42A, on which an object, namely a substrate W, is placed and illuminated by the light irradiation unit 18; and a position calibration area 42B, which is a region for calibrating the position of the light irradiated by the light irradiation unit 18.

[0075] The substrate W is positioned at a predetermined location within the object placement area 42A. Thus, the positional relationship between the stage 42 and the substrate W is predetermined. In the position calibration area 42B, the position of the light irradiated from the light irradiation unit 18 into the position calibration area 42B is determined by the detection unit 62 (see reference). Figure 2) Detection. Furthermore, in the position calibration area 42B, before performing optical processing on the substrate W in the object configuration area 42A, the correspondence between the set value of the direction of the light irradiated from the light irradiation unit 18 and the irradiation position of the detected light is calibrated.

[0076] A light-transmitting portion 142 is provided in at least a portion of the position calibration region 42B to allow light to pass through. The light-transmitting portion 142 is made of a transparent material such as glass (SiO2) or transparent resin (e.g., silicone resin). The light-transmitting portion 142 is provided from the upper surface to the lower surface of the stage 42 corresponding to the position calibration region 42B. Light irradiated from the light irradiation portion 18 and transmitted to the light-transmitting portion 142 passes from the upper surface to the lower surface of the stage 42.

[0077] The light-transmitting portion 142 has at least one ( Figure 3 There are two scattering sections 142A. The scattering sections 142A are made of transparent material, allowing the illuminated light to be scattered while simultaneously reflected or transmitted. The location of the scattering sections 142A is a predetermined position on the stage 42. That is, the position of the scattering sections 142A within the entire stage 42 is predetermined. Figure 3 In this light irradiation section 18, each scattering part 142A is disposed at the end of the light irradiation area along the X-axis. However, the position of the scattering part 142A can be any specific position on the stage 42, and is not limited to the end of the light irradiation area of ​​the light irradiation section 18. The scattering part 142A has the characteristic of scattering incident light, and is obtained, for example, by sandblasting the glass material or by frosting it with hydrofluoric acid. Figure 3 In this process, each scattering part 142A is formed on the upper surface of the light-transmitting part 142, but at least one scattering part 142A may also be formed on the lower surface of the light-transmitting part 142.

[0078] In addition, Figure 3 In the illustrated case, the object placement area 42A and the position calibration area 42B are separate areas, but at least a portion of these areas may overlap. That is, the light-transmitting portion 142 may also be provided in at least a portion of the area where the substrate W is disposed. In this case, for example, the position calibration of the light irradiated from the light irradiation portion 18 can be performed at the position where the substrate W is disposed, even when the substrate W is not disposed.

[0079] Furthermore, the light-transmitting portion 142 may have a scattering portion 142A formed throughout its entire range. That is, it is possible for light to be scattered throughout the entire range of the light-transmitting portion 142 in such a way that there is no portion that only transmits light.

[0080] In addition, Figure 3The light-transmitting portion 142 extends along the X-axis direction, and a scattering portion 142A is provided at each end along the X-axis direction. However, the light-transmitting portion 142 can also be divided into multiple parts along the X-axis direction. In the case where multiple scattering portions 142A are provided on a single-piece light-transmitting portion 142 (i.e....) Figure 3 In the case shown, the light-transmitting part 142 can be installed while maintaining the positional accuracy between the multiple scattering parts 142A when the light-transmitting part 142 is made of transparent material. Figure 3 In the case of embedding, it is mounted on the stage 42. Therefore, no positional shift occurs between the scattering sections 142A when mounted on the stage 42, thus, the accuracy of calibration performed using multiple scattering sections 142A can be maintained at a high level.

[0081] Figure 4 It is mainly shown Figure 2 A cross-sectional view of an example structure of the light irradiation section 18 and the stage 42 in the illustrated structure. (Example) Figure 4 As illustrated, the light irradiation unit 18 includes: a galvanometer reflector or multi-faceted reflector, i.e., a scanner 18A, which controls the direction of the irradiated light along the X-axis or Y-axis; and a converging lens 18B that converges light from a light source (not shown). Figure 4 In this process, the light irradiated through the converging lens 18B and then through the irradiation window 20 formed of quartz is, for example, a laser 18C. The laser 18C can scan the substrate W disposed on the upper surface of the stage 42 along the X-axis direction under the control of the scanner 18A. Here, the light irradiation unit 18 is preferably able to control the light along both the X-axis and Y-axis directions, but the light irradiation unit 18 may also be able to control the light along either the X-axis or the Y-axis direction.

[0082] The stage 42 has a position calibration area 42B (see reference) Figure 3 The light-transmitting portion 142 and the scattering portion 142A formed on the upper surface of the light-transmitting portion 142 are provided. The laser 18C irradiated from the light irradiation portion 18 can scan within a range that reaches at least the scattering portion 142A in the X-axis direction.

[0083] A detection unit 62 for detecting light is disposed below the stage 42. The detection unit 62 includes: a converging unit 62A for converging light within the vacuum cavity 12; an optical fiber 62B for transmitting the light converged by the converging unit 62A to the outside of the vacuum cavity 12; and a photodetector 62C for detecting the light transmitted to the outside of the vacuum cavity 12 via the optical fiber 62B. Since the photodetector 62C is disposed outside the vacuum cavity 12, it is possible to suppress the intrusion of gas that can be released from the photodetector 62C into the vacuum cavity 12.

[0084] Figure 5 and Figure 6 This is a schematic diagram illustrating the structure and function of the convergence unit 62A. (See diagram below.) Figure 5 and Figure 6 As illustrated, the converging unit 62A includes a converging lens 162, which focuses on the light irradiation section 18 (see reference 18). Figure 4 The incident light converges along its optical axis.

[0085] exist Figure 5 In the case shown, light is emitted from the light irradiation section 18 (refer to...) Figure 4 The incident laser 18C (parallel light) reaches the converging unit 62A only through the light-transmitting part 142 on the stage 42. On the other hand, in Figure 6 In the case shown, light is emitted from the light irradiation section 18 (refer to...) Figure 4 The incident laser 18C passes through the scattering part 142A and the light-transmitting part 142 on the stage 42 and reaches the converging unit 62A. Furthermore, in Figure 6 In the process, laser 18C passes through both scattering section 142A and light-transmitting section 142, but laser 18C may also pass through only scattering section 142A.

[0086] exist Figure 5 In the case shown, the laser 18C, passing through the light-transmitting portion 142 other than the scattering portion 142A, reaches the converging unit 62A in a manner that does not significantly change the irradiation range and direction. Then, most of the laser 18C is focused by the converging lens 162 in the converging unit 62A and incident on the optical fiber 62B disposed at the converging position of the converging lens 162.

[0087] On the other hand, Figure 6 In the case shown, the laser 18C passing through the scattering section 142A in the light-transmitting section 142 undergoes light scattering when it passes through the scattering section 142A. Therefore, within the irradiation range of the laser 18C, the scattered light ( Figure 6 In the expanded state of the sandy area, laser 18C reaches converging unit 62A. Furthermore, laser 18C is converged by converging lens 162 in converging unit 62A.

[0088] At this time, the laser 18C, whose illumination range is expanded by scattering light through the scattering section 142A, contains many components that are not parallel light, and at least a portion of these components do not converge to the converging position of the converging lens 162. Therefore, apart from the laser 18C that does not converge to the converging position, only a portion of the laser 18C reaches the optical fiber 62B.

[0089] As described above, when the laser 18C irradiates the upper surface of the stage 42, most of it is focused by the converging lens 162 and reaches the optical fiber 62B when passing through the light-transmitting part 142 (excluding the scattering part 142A). However, when passing through the scattering part 142A in the light-transmitting part 142, only a portion is focused by the converging lens 162 and reaches the optical fiber 62B. Then, the light reaching the optical fiber 62B is respectively focused by the photodetector 62C (refer to...). Figure 4 It was detected in ).

[0090] Therefore, in the case where the laser 18C irradiates the light-transmitting portion 142 other than the scattering portion 142A, and in the case where it irradiates the scattering portion 142A, the detection portion 62 (refer to...) Figure 4 The amount of light detected by the laser 18C is different. Therefore, based on the amount of light output from the photodetector 62C, the control unit 22 can set the timing of the detected light amount change to the moment when light illuminates the boundary of the light-transmitting portion 142 where the scattering portion 142A is formed. Moreover, the control unit 22 sets the timing of the scanner 18A (refer to...) at this moment... Figure 4 The setting value corresponds to the position (specifically, the boundary position) of the scattering section 142A, enabling calibration of the position of the irradiated light. Therefore, in subsequent processes, when performing photoprocessing on the substrate W disposed on the upper surface of the stage 42, the position of the light irradiated from the light irradiation section 18 can be precisely aligned under the control of the control unit 22.

[0091] Furthermore, the light-transmitting portion 142, which is irradiated by the light irradiation portion 18, is made of a transparent material. Therefore, even when the light-transmitting portion 142 is repeatedly irradiated with high-intensity light in order to calibrate the position of the light irradiated by the light irradiation portion 18, damage to the target (i.e., the light-transmitting portion 142) being irradiated by the light can be suppressed.

[0092] <Regarding the shape of the scattering part>

[0093] Figure 7 This is a top view showing an example of the shape of the scattering section 142A. (Example) Figure 7 As illustrated, the scattering section 142A is on the stage 42 (see reference). Figure 3 , Figure 4 The upper surface of the scattering part 142A extends along the X-axis and Y-axis directions, and for example, when viewed from above, it can be shaped as two triangles arranged opposite each other with one vertex connected to each other (butterfly shape). In this shape, the width of the scattering part 142A in the X-axis direction (the total width of the formed area) increases towards the center in the Y-axis direction. Alternatively, the width of the scattering part 142A in the Y-axis direction decreases towards the center in the X-axis direction.

[0094] Figure 8 This shows scanning along the X-axis. Figure 7 The photodetector 62C obtained in the case of the scattering part 142A with the illustrated shape (see reference) Figure 4 A diagram showing an example of the detection signal in (). In Figure 8 In the example shown, the light is detected by the photodetector 62C at predetermined sampling times (T1, T2, T3, T4, and T5) and a detection signal S is output. The stage 42 (see reference) is changed with each scan. Figure 3 , Figure 4 The position of ) in the Y-axis direction. Figure 8 In the detection signal S shown, the black signal represents a strong signal (that is, a signal with a large amount of detected light), and the white signal represents a weak signal (that is, a signal with a small amount of detected light).

[0095] When the photodetector 62C detects light illuminating the butterfly-shaped scattering part 142A (refer to...) Figure 7 When the light is such, Figure 8 As illustrated, at the ends on the positive and negative Y-axis sides, regions of weak signal strength are separately distributed in the X-axis direction. Therefore, during the period between sampling time T1 and sampling time T5, the intensity of the detection signal S fluctuates (spreads) around sampling time T3. On the other hand, at the central part in the Y-axis direction, regions of weak signal strength are continuously distributed in the X-axis direction. Therefore, during the period between sampling time T1 and sampling time T5, the intensity of the detection signal S does not fluctuate.

[0096] Thus, it can be determined that the position of the detection signal S in the Y-axis direction during a scan without fluctuation is the center position of the scattering section 142A in the Y-axis direction. That is, by comparing the fluctuations of the detection signal S during multiple scans, the center position of the scattering section 142A can be determined with high precision.

[0097] Furthermore, it can be known that the position in the X-axis direction corresponding to the midpoint of the period during which the intensity of the detection signal S weakens (including periods of continuous weakening and periods of intermittent weakening) is the center position in the X-axis direction of the scattering unit 142A. That is, it can be known that when the detection signal S is output at sampling time T1 and sampling time T5, sampling time T3 is the center position.

[0098] On the other hand, scanning along the X-axis direction will Figure 7 The example shows the scattering portion (butterfly shape) of the shape after rotating it 90 degrees (this is the same as scanning along the Y-axis). Figure 7 In the case of the scattering part with the illustrated shape, the regions with weak signal strength are arranged continuously in the X-axis direction at the ends on the positive Y-axis side and the ends on the negative Y-axis side, and the regions with weak signal strength are arranged in the shortest position in the X-axis direction at the center in the Y-axis direction.

[0099] Thus, it can be determined that the position of the weak detection signal S in the Y-axis direction during the shortest scan is the center position of the scattering part in the Y-axis direction. That is, by comparing the duration of weak signal intensity in multiple scans, the center position of the scattering part can be determined with high precision.

[0100] Furthermore, it can be seen that the position in the X-axis direction corresponding to the midpoint of the period during which the detection signal S weakens (in the case of outputting the detection signal S from sampling time T1 to sampling time T5, which is sampling time T3) is the center position of the scattering part in the X-axis direction.

[0101] Thus, because the scattering part is butterfly-shaped, the center position of the scattering part in the X-axis or Y-axis direction can be determined with high precision. Therefore, the light irradiation part 18 (see reference 18) can be positioned with high precision. Figure 4 The position of the irradiated light is calibrated and aligned.

[0102] The shape of the scattering part is not limited to Figure 7 and Figure 8 The shape shown, where the area gradually decreases towards the center in the X-axis direction, can also be a shape where the area decreases discontinuously towards the center in the X-axis direction, or a shape where the area increases towards the center in both the X-axis and Y-axis directions. Furthermore, the shape of the outer edge of the scattering portion is not limited to... Figure 7 and Figure 8 The straight line shown may also include a curve in at least a portion.

[0103] <Regarding cases with multiple light-illuminating sections>

[0104] Figure 9 This is a cross-sectional view showing an example of a structure with multiple light-illuminating parts. For example... Figure 9 As illustrated, the light irradiation device includes multiple light irradiation sections 118 and 218.

[0105] The light irradiation unit 118 includes: a galvanometer reflector, i.e., a scanner 118A, which controls the direction of the irradiated light along the X-axis; and a converging lens 118B, which converges light from a light source (not shown). Figure 9 In the process, the light irradiated by the converging lens 118B and then by the irradiation window 20A formed of quartz or the like is, for example, a laser 118C. The laser 118C can scan the substrate W disposed on the upper surface of the stage 42 along the X-axis direction by the control of the scanner 118A.

[0106] Similarly, the light irradiation unit 218 includes: a galvanometer reflector, i.e., a scanner 218A, which controls the direction of the irradiated light along the X-axis; and a converging lens 218B, which converges light from a light source (not shown). Figure 9 In the process, the light irradiated by the converging lens 218B and then by the irradiation window 20B formed of quartz or the like is, for example, a laser 218C. The laser 218C can scan the substrate W disposed on the upper surface of the stage 42 along the X-axis direction by the control of the scanner 218A.

[0107] In this light irradiation section 118, the light irradiation area in the X-axis direction extends from the position corresponding to the scattering portion 142B formed in the light-transmitting section 142 to the position corresponding to the scattering portion 142C formed in the light-transmitting section 142. Conversely, the light irradiation area in the X-axis direction of the light irradiation section 118 extends from the position corresponding to the scattering portion 142C formed in the light-transmitting section 142 to the position corresponding to the scattering portion 142D formed in the light-transmitting section 142. That is, the scattering portion 142C is disposed at the connection between the light irradiation area of ​​the light irradiation section 118 and the light irradiation area of ​​the light irradiation section 218.

[0108] The detection unit 62 is positioned below the stage 42, which corresponds to the positions of the scattering units 142B, 142C, and 142D, respectively. The converging unit 62A in each detection unit 62 is positioned on the optical axis of the light incident from the corresponding light irradiation unit.

[0109] By configuring the scattering section 142B, scattering section 142C, and scattering section 142D in this way, the connection between the light irradiation area of ​​the light irradiation section 118 and the light irradiation area of ​​the light irradiation section 218 is positioned by the common scattering section 142C, thus suppressing the positional shift between the two light irradiation areas.

[0110] <Regarding the effects produced by the above-described implementation methods>

[0111] Next, examples of the effects produced by the embodiments described above will be shown. Furthermore, in the following description, the effects are described based on the specific structures exemplified by the embodiments described above, but other specific structures exemplified in this specification may be used to produce the same effects. That is, for convenience, sometimes only one of the corresponding specific structures will be described as representative, but the representative specific structure may be replaced with other corresponding specific structures.

[0112] According to the embodiments described above, the light irradiation device includes: a stage 42, at least one light irradiation unit 18 (or, light irradiation unit 118, light irradiation unit 218), and a determining unit. Here, the determining unit corresponds, for example, to a control unit 22. At least a portion of the stage 42 is made of a transparent material. The light irradiation unit 18 irradiates light onto the upper surface of the stage 42. The stage 42 is provided with a light-transmitting part 142 for allowing light to pass through, and at least one scattering part 142A (or, scattering part 142B, scattering part 142C, scattering part 142D) for scattering light. The detection unit 62 detects at least one of the light transmitted through the light-transmitting part 142 and the light scattered by the scattering part 142A. The control unit 22 determines the position of at least one of the light-transmitting part 142 and the scattering part 142A based on the amount of light detected.

[0113] With this structure, the scattering portion 142A, which is irradiated by light, is made of a transparent material, thus reducing damage to the irradiated area (scattering portion 142A) even when irradiated by high-intensity light such as laser light. Therefore, the positional accuracy of the light detected by the detection unit 62 is not easily reduced. In addition, by detecting only the transmitted light passing through the light-transmitting portion 142 and the scattered light passing through the scattering portion 142A, a sufficient amount of light can be obtained to maintain detection accuracy. Furthermore, the irradiation range of the light scattered by the scattering portion 142A is larger than that of the light transmitted through the light-transmitting portion 142, thus reducing the overall amount of light incident on the optical fiber 62B. Therefore, it is possible to determine whether the light detected by the detection unit 62 is light that has passed through the light-transmitting portion 142 or light that has been scattered by the scattering portion 142A based on the difference between the amount of transmitted light and the amount of scattered light. Therefore, it is possible to determine whether the scattering portion 142A is disposed at a position on the upper surface of the stage 42 irradiated by light. That is, it is possible to determine the position of at least one of the light-transmitting portion 142 and the scattering portion 142A.

[0114] Furthermore, the same effect can be achieved even if other structures illustrated in this specification are appropriately added to the above-described structure, that is, if other structures in this specification not mentioned as the above-described structure are appropriately added.

[0115] Furthermore, according to the embodiment described above, the control unit 22 determines the position of the boundary between the light-transmitting part 142 and the scattering part 142A based on the difference in the amount of detected light. With this structure, the position of the change in the amount of detected light can be determined as the position of the boundary between the light-transmitting part 142 and the scattering part 142A based on the difference between the amount of transmitted light and the amount of scattered light.

[0116] Furthermore, according to the embodiment described above, when viewed from above the stage 42, the scattering section 142A has a butterfly shape formed by connecting two triangles at one vertex to each other. Based on this structure, it can be determined that the center position of the scattering section 142A is the midpoint between periods when the detection signal S does not fluctuate or when the intensity of the detection signal S weakens. That is, the center position of the scattering section 142A can be determined with high precision by comparing the intensity of the detection signal S detected in multiple scans.

[0117] Furthermore, according to the embodiment described above, the light irradiated from the light irradiation unit 18 is a laser. With this structure, even when irradiated with high-intensity light such as a laser, damage to the scattering unit 142A can be reduced.

[0118] Furthermore, according to the embodiment described above, the detection unit 62 includes a converging lens 162. The converging lens 162 converges at least one of the light transmitted through the light-transmitting portion 142 and the light scattered by the scattering portion 142A. With this structure, it is easy to ensure the amount of light used to maintain detection accuracy by converging the light.

[0119] Furthermore, according to the embodiments described above, the light irradiation device includes a cavity containing a stage 42. This cavity, for example, corresponds to a vacuum cavity 12. The vacuum cavity 12 is situated in a vacuum or depressurized gas environment. The detection unit 62 includes an optical fiber 62B and a photodetector 62C. The optical fiber 62B transmits light focused by the converging lens 162 to the outside of the vacuum cavity 12. The photodetector 62C is disposed outside the vacuum cavity 12 and detects the light transmitted by the optical fiber 62B. With this structure, the photodetector 62C in the detection unit 62 is positioned outside the vacuum cavity 12, thus preventing the release gas emitted from the photodetector 62C from entering the vacuum cavity 12.

[0120] According to the embodiments described above, in the light irradiation method, light is irradiated onto the upper surface of a stage 42 made of a transparent material. The stage 42 is provided with a light-transmitting portion 142 for allowing light to pass through and at least one light-scattering portion 142A for scattering light. Then, at least one of the light transmitted through the light-transmitting portion 142 and the light scattered by the light-scattering portion 142A is detected. Then, the position of at least one of the light-transmitting portion 142 and the light-scattering portion 142A is determined based on the amount of light detected.

[0121] With this structure, the scattering portion 142A, which is irradiated by light, is made of a transparent material, thus reducing damage to the irradiated area (scattering portion 142A) even when irradiated by high-intensity light such as laser light. Therefore, the positional accuracy of the light detected by the detection unit 62 is less likely to decrease. Furthermore, by detecting only the transmitted light passing through the light-transmitting portion 142 and the scattered light passing through the scattering portion 142A, a sufficient amount of light can be obtained to maintain detection accuracy. Additionally, based on the difference between the amount of transmitted light and the amount of scattered light, it can be determined whether the light detected by the detection unit 62 is light that has passed through the light-transmitting portion 142 or light that has been scattered by the scattering portion 142A. Therefore, the position of at least one of the light-transmitting portion 142 and the scattering portion 142A can be determined.

[0122] Furthermore, the same effect can be achieved by appropriately adding other structures illustrated in this specification to the above-described structure, that is, by appropriately adding other structures in this specification that are not mentioned as the above-described structure.

[0123] <Variations on the implementation methods described above>

[0124] The embodiments described above also describe the material, size, shape, relative configuration relationship, or implementation conditions of each structural component, but these are only examples and not limitations in each respect.

[0125] Therefore, numerous variations and equivalents, not illustrated, can be conceived within the scope of the technology disclosed in this specification. For example, this includes cases where at least one structural member is modified, added to, or omitted.

[0126] Furthermore, in the embodiments described above, even if the material name is not specifically specified, other additives, such as alloys, may be included in the material as long as there is no contradiction.

Claims

1. An optical irradiation apparatus, wherein provided are: a stage on an upper surface of which a substrate as an object of optical irradiation is arranged and at least a part of which is made of a transparent material; and at least one optical irradiation section for scanning the substrate and the upper surface of the stage by light, a light-transmitting section for transmitting the light and at least one scattering section for scattering the light are provided on the stage, the optical irradiation apparatus further provided with: a detection section for detecting at least one of the light transmitted through the light-transmitting section and the light scattered at the scattering section in the scanning by the optical irradiation section; and a determination section for determining a position of at least one of the light-transmitting section and the scattering section based on an amount of the detected light, the scattering section is made of a transparent material.

2. The optical irradiation apparatus according to claim 1, wherein the determination section determines a position of a boundary between the light-transmitting section and the scattering section based on a difference in the amount of the detected light.

3. The optical irradiation apparatus according to claim 1 or 2, wherein the scattering section has a shape of a butterfly in which one apex of two triangles is connected to each other when the stage is viewed from above.

4. The optical irradiation apparatus according to claim 1 or 2, wherein the light irradiated from the optical irradiation section is laser light.

5. The optical irradiation apparatus according to claim 1 or 2, wherein the detection section is provided with a converging lens for converging at least one of the light transmitted through the light-transmitting section and the light scattered at the scattering section.

6. The optical irradiation apparatus according to claim 5, wherein the optical irradiation apparatus is further provided with a cavity in which the stage is built-in, the cavity is in a vacuum or a reduced-pressure gas environment, the detection section is further provided with: an optical fiber for transmitting the light converged by the converging lens to the outside of the cavity; and a light detector arranged outside the cavity and detecting the light transmitted by the optical fiber.

7. An optical irradiation method, wherein comprising a process of scanning a substrate as an object of optical irradiation and an upper surface of a stage on which the substrate is arranged and which is made of a transparent material by light, a light-transmitting section for transmitting the light and at least one scattering section for scattering the light are provided on the stage, the optical irradiation method further comprising: a process of detecting at least one of the light transmitted through the light-transmitting section and the light scattered at the scattering section in the process of scanning by light; and a process of determining a position of at least one of the light-transmitting section and the scattering section based on an amount of the detected light, the scattering section is made of a transparent material. ​

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