CN115701368A

CN115701368A - Light irradiation device and light irradiation method

Info

Publication number: CN115701368A
Application number: CN202210874580.1A
Authority: CN
Inventors: 小田晃司
Original assignee: Screen Holdings Co Ltd
Current assignee: Screen Holdings Co Ltd
Priority date: 2021-08-02
Filing date: 2022-07-22
Publication date: 2023-02-10
Also published as: TW202306681A; JP2023021607A; KR20230019778A; TWI808773B

Abstract

The invention provides a light irradiation device and a light irradiation method, which can inhibit the reduction of detection precision caused by irradiation light. The light irradiation device is provided with: an object stage at least a portion of which is formed of a transparent material; and at least one light irradiation unit for irradiating light to the upper surface of the stage, wherein the stage is provided with a light transmission unit for transmitting light and at least one scattering unit for scattering light, and the light irradiation device further comprises: a detection unit for detecting at least one of the light transmitted through the light transmission unit and the light scattered by the scattering unit; and a specifying unit that specifies a position of at least one of the light transmitting unit and the scattering unit based on the detected light amount.

Description

Light irradiation device and light irradiation method

Technical Field

The technology disclosed in the present specification relates to a technology for detecting irradiated light.

Background

Conventionally, a photo-processing technique for processing an object by irradiation with light such as laser light has been used (for example, see patent document 1).

Patent document 1: japanese patent laid-open publication No. 2006-272430

Disclosure of Invention

Problems to be solved by the invention

In order to improve the processing accuracy in the above-described optical processing technique, it is important to control the position irradiated with light with high accuracy.

As a method of detecting the position to which light is applied, for example, there is a method of detecting the position to which light is applied by imaging the light with an area camera. However, there is a problem that, particularly when high-intensity light such as laser light is detected, detection accuracy is lowered due to damage accumulated in a member or an optical element disposed at a portion irradiated with the light.

The technique disclosed in the present specification has been made in view of the above-described problems, and is a technique for suppressing a decrease in detection accuracy due to irradiation light.

Means for solving the problems

A light irradiation device according to a first aspect of the technology disclosed in the present specification includes: an object stage, at least a portion of which is formed of a transparent material; and at least one light irradiation unit configured to irradiate light onto an upper surface of the stage, the stage being provided with a light transmission unit configured to transmit the light therethrough and at least one scattering unit configured to scatter the light, the light irradiation apparatus further comprising: a detection unit for detecting at least one of the light transmitted through the light transmission unit and the light scattered by the scattering unit; and a determination unit that determines a position of at least one of the light transmission unit and the scattering unit based on the detected light amount of the light.

A light irradiation device of a second aspect of the technology disclosed in the present specification is related to the light irradiation device of the first aspect, and the determination section determines a position of a boundary between the light-transmitting section and the scattering section based on a difference in the detected light amount of the light.

A light irradiation device according to a third aspect of the technology disclosed in the present specification is related to the light irradiation device of the first or second aspect, and the scattering portion has a butterfly shape in which one vertexes of two triangles are connected to each other in a plan view of the stage.

A light irradiation device of a fourth aspect of the technology disclosed in the present specification is associated with the light irradiation device of any one of the first to third aspects, and the light irradiated from the light irradiation section is laser light.

A fifth aspect of the technology disclosed in the present specification relates to the light irradiation device according to any one of the first to fourth aspects, wherein the detection unit includes a condensing lens for condensing at least one of the light transmitted through the light transmission unit and the light scattered by the scattering unit.

A light irradiation device according to a sixth aspect of the technology disclosed in the present specification is related to the light irradiation device according to the fifth aspect, further comprising a chamber in which the stage is placed, wherein the chamber is in a vacuum or reduced-pressure gas atmosphere, and the detection unit further comprises: an optical fiber transmitting the light converged by the converging lens to an outside of the cavity; and a light detector disposed outside the cavity and detecting the light transmitted by the optical fiber.

A light irradiation method according to a seventh aspect of the technology disclosed in the present specification, including a step of irradiating light onto an upper surface of a stage made of a transparent material, the stage being 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 including: detecting at least one of the light transmitted through the light transmitting portion and the light scattered by the scattering portion; and determining a position of at least one of the light transmitting portion and the scattering portion based on the detected light amount of the light.

Effects of the invention

According to at least the first and seventh aspects of the technology disclosed in the present specification, since the scattering portion to which light is applied is made of a transparent material, damage to the portion to which light is applied can be reduced even when light of high intensity such as laser light is applied. Therefore, the positional accuracy of the light detected by the detection unit is not easily degraded.

In addition, objects, features, aspects and advantages related to the technology disclosed in the present specification will become more apparent from the detailed description and the accompanying drawings shown below.

Drawings

Fig. 1 is a perspective view schematically showing an example of the structure of a light irradiation device according to an embodiment.

Fig. 2 is a cross-sectional view showing an example of the internal structure and the peripheral structure of the vacuum chamber of the light irradiation device of the embodiment.

Fig. 3 is a perspective view mainly showing the light irradiation section and the stage in the configuration illustrated in fig. 2.

Fig. 4 is a sectional view mainly showing an example of the structure of the light irradiation section and the stage in the structure illustrated in fig. 2.

Fig. 5 is a schematic diagram showing the structure and action of the convergence unit.

Fig. 6 is a schematic diagram illustrating the structure and action of the convergence unit.

Fig. 7 is a plan view showing an example of the shape of the scattering portion.

Fig. 8 is a diagram showing an example of detection signals of the photodetector obtained when the scattering portion having the shape illustrated in fig. 7 is scanned in the X-axis direction.

Fig. 9 is a cross-sectional view showing an example of a configuration in a case where a plurality of light irradiation sections are provided.

Description of the reference numerals:

1: light irradiation device

18: light irradiation section

18B: converging lens

18C: laser beam

42: object stage

62: detection part

62B: optical fiber

62C: light detector

118: light irradiation unit

118B: converging lens

118C: laser beam

142: light-transmitting part

142A: scattering part

142B: scattering part

142C: scattering part

142D: scattering part

162: converging lens

218: light irradiation unit

218B: converging lens

218C: laser

Detailed Description

Hereinafter, embodiments will be described with reference to the drawings. In the following embodiments, detailed features and the like are shown for explaining the technology, but these are examples, and all the features are not necessarily essential features for enabling the implementation of the embodiments.

The drawings are schematically illustrated, and the structures are omitted or simplified as appropriate in the drawings for the convenience of description. The mutual relationship between the size and the position of the structures and the like shown in the different drawings is not necessarily described accurately, and may be changed as appropriate. In addition, in the drawings such as a plan view of a non-sectional view, hatching may be added to facilitate understanding of the contents of the embodiments.

In the following description, the same components are denoted by the same reference numerals and are shown with the same names and functions. Therefore, detailed descriptions thereof may be omitted to avoid redundancy.

In addition, in the description described in the present specification, in the case of describing "including", or "having" a certain structural member or the like, unless otherwise specified, it is not an exclusive expression excluding the presence of other structural members.

In the description of the present specification, even if ordinal numbers such as "first" and "second" are used in some cases, these terms are used for facilitating understanding of the contents of the embodiments, and are not limited to the order in which the ordinal numbers are generated.

In the description of the present specification, the expression "a.. Axis positive direction" or "a.. Axis negative direction" or the like means that a direction of an arrow along the illustrated.. Axis is a positive direction, and a direction opposite to the arrow of the illustrated.. Axis is a negative direction.

In addition, in the description set forth in the present specification, expressions indicating relative or absolute positional relationships, such as "in one direction", "parallel", "orthogonal", "central", "concentric" or "coaxial", and the like, include, unless otherwise specified, cases where positional relationships thereof are strictly expressed and cases where angular or distance displacements occur within a range where tolerance or equivalent degree of function can be obtained.

In the description of the present specification, even though terms indicating specific positions or directions such as "up", "down", "left", "right", "side", "bottom", "front" or "back" are used in some cases, these terms are used for ease of understanding the contents of the embodiments and are not related to the positions or directions in actual implementation.

< embodiment >

The following describes the light irradiation device according to the present embodiment. In the following embodiments, a light irradiation device in which the chamber is vacuum or a reduced-pressure gas atmosphere is described as an example, but the present invention is also applicable to a case where the chamber is not vacuum.

< Structure of light irradiation apparatus >

Fig. 1 is a perspective view schematically showing an example of the structure of a light irradiation device 1 according to the present embodiment. In fig. 1, for convenience, a chamber frame for supporting the vacuum chamber 12, wiring for actual connection, and the like are not illustrated. In addition, the "vacuum" in the present embodiment is preferably a high vacuum (for example, 0.00001 Pa) in order to prevent the characteristic degradation of the substrate W, but a vacuum degree lower than the high vacuum is also included.

As illustrated in fig. 1, the light irradiation device 1 includes: a vacuum chamber 12; an external fixing portion 14 such as a stone slab; a bellows 16 as a stretchable member, which connects the vacuum chamber 12 and the external fixing portion 14 and is formed of, for example, stainless steel; a light irradiation unit 18 for irradiating light into the vacuum chamber 12; a vacuum pump 21 for reducing the pressure in the vacuum chamber 12 to a vacuum state; and a control unit 22 for controlling the respective driving units of the light irradiation device 1. In the above, as an example of the stretchable member, a corrugated tube made of stainless steel or the like is shown, but a stretchable member made of a metal other than stainless steel or a stretchable member made of a resin or the like may be used according to the required specifications. The shape of the stretchable member may be other than the bellows shape like the bellows 16A described above.

The vacuum chamber 12 has a space for accommodating the substrate W therein. Examples of the substrate to be processed include a semiconductor wafer, a glass substrate for a liquid crystal display device, a substrate for a Flat Panel Display (FPD) such as an organic EL (electroluminescence) display device, a substrate for an optical disk, a substrate for a magnetic disk, a substrate for an optical disk, a glass substrate for a photomask, a ceramic substrate, a substrate for a Field Emission Display (FED), a substrate for a solar cell, and the like. The substrate W is, for example, a substrate having a thin film formed on the upper surface thereof.

An opening 12A through which the substrate W passes when the substrate W is carried in and out is formed in a side surface of the vacuum chamber 12. When the vacuum chamber 12 becomes a vacuum state, the opening portion 12A is appropriately closed. Other structures accommodated inside the vacuum chamber 12 will be described later.

The light irradiation unit 18 irradiates light on the upper surface of the substrate W accommodated in the vacuum chamber 12. At this time, the substrate W is aligned in advance by the detection unit 62 or the like described later. The light irradiation unit 18 performs ablation (ablation) processing of the substrate W by, for example, laser light irradiation. The light irradiation unit 18 may be a member that irradiates light such as an electron beam according to the purpose of processing or the like. The light irradiation unit 18 irradiates light from the outside of the vacuum chamber 12 to the upper surface of the substrate W accommodated in the vacuum chamber 12 through an irradiation window (transparent plate made of quartz or the like) not shown. Then, the substrate W in the vacuum chamber 12 is moved relative to the light irradiation unit 18 or the upper surface of the substrate W is scanned by light under the control of an optical system in the light irradiation unit 18. The light irradiation unit 18 is disposed on the upper surface of the stage 24 fixed to the external fixing unit 14.

The control section 22 may include: a storage device including a memory (storage medium) including, for example, a Hard Disk Drive (HDD), a Random Access Memory (RAM), a Read Only Memory (ROM), a flash memory, a volatile or nonvolatile semiconductor memory, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a DVD, or the like; a processing circuit such as a Central Processing Unit (CPU) that executes a program stored in the storage device, an external CD-ROM, an external DVD-ROM, an external flash memory, or the like; input devices capable of inputting information, such as a mouse, a keyboard, a touch panel, and various switches; and an output device such as a display, a liquid crystal display device, or a lamp capable of outputting information.

The control unit 22 controls the output of the light source and the direction of light irradiation in the light irradiation unit 18, controls the output of the vacuum pump 21, and controls the driving of each driving unit (for example, a driving unit of a linear motor mechanism or a driving unit of an elevator pin mechanism) described later. As will be described later, the control unit 22 can specify the position of the stage on which the substrate W is placed based on the detection value of the light irradiated from the light irradiation unit 18.

Fig. 2 is a cross-sectional view showing an example of the internal structure and the surrounding structure of the vacuum chamber 12 of the light irradiation device 1 of the present embodiment. As illustrated in fig. 2, the vacuum chamber 12 includes: a stage 42 on which a substrate W is disposed; a slider 44 that is movable in the Y-axis direction and supports the stage 42 from below; a pedestal 46 fixed to the external fixing portion 14 independently of the vacuum chamber 12; a linear guide 48 fixed to the base 46 and extending in the Y-axis direction; a linear motor mechanism 50 that moves the slider 44 in the Y-axis direction along the linear guide 48; an elevator pin mechanism 52 having elevator pins 52A, the elevator pins 52A penetrating through-holes (not shown) formed in the stage 42 to support the substrate W; and a detection unit 62 disposed below the stage 42 (on the negative Z-axis side in fig. 2).

The stage 42 faces the processing surface of the substrate W upward and holds the substrate W substantially horizontally. The detailed structure of the stage 42 is described later. The slider 44 supporting the stage 42 is moved in the Y-axis direction by the linear motor mechanism 50, and the light irradiated from the light irradiation unit 18 is scanned in the X-axis direction, whereby the entire processing area of the substrate W can be scanned by the light in a plan view. Alternatively, the light irradiated from the light irradiation unit 18 may scan the entire processing region of the substrate W with the light in a plan view by scanning the light in the X-axis direction and the Y-axis direction. The lifter pin mechanism 52 is fixed to the base 46.

The linear motor mechanism 50 is fixed to an external fixing portion 14 located on a side of the vacuum chamber 12 via an opening portion 12B formed in a side surface of the vacuum chamber 12. Specifically, the linear motor mechanism 50 is fixed to an end portion of the hollow columnar member 14A inserted into the bellows 16A welded to the opening portion 12B. At this time, the wiring and the like connected to the linear motor mechanism 50 is led out to the outside of the vacuum chamber 12 through the inside of the columnar member 14A. Further, the columnar member 14A included in the external fixing portion 14 is fixed to the external member 14B included in the external fixing portion 14. In addition, the columnar member 14A does not contact the bellows 16A connected to the side of the vacuum chamber 12.

The base 46 is fixed to the external fixing portion 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 an end portion of the columnar member 14C that passes through the bellows 16B welded to the opening 12C. Further, the columnar member 14C included in the external fixing portion 14 is fixed to the external member 14B included in the external fixing portion 14. In addition, the columnar member 14C does not contact the bellows 16B connected to the bottom surface of the vacuum chamber 12.

In fig. 2, the external fixing portions 14 are disposed over the sides and the lower side of the vacuum chamber 12, and the external fixing portions 14 at these positions are not necessarily continuous, may be provided at these positions in a dispersed manner, and may be provided only at arbitrary positions. The vacuum chamber 12 is supported and fixed by a chamber frame (not shown) separately from the bellows 16B from the vertical direction, but the chamber frame is provided separately from the external fixing portion 14.

The detection unit 62 is located below the stage 42 and can detect the light irradiated from the light irradiation unit 18. The detailed configuration of the detection unit 62 will be described later.

Fig. 3 is a perspective view mainly showing the light irradiation section 18 and the stage 42 in the configuration illustrated in fig. 2. Fig. 3 shows a state in which a substrate W is disposed on the upper surface of the stage 42. The light irradiation unit 18 can scan the light irradiation direction in the X-axis direction in fig. 3, and the stage 42 can be moved in the Y-axis direction by a linear motor mechanism 50 (see fig. 2). Thus, the light irradiated from the light irradiation unit 18 onto the upper surface of the stage 42 can form a rectangular irradiation region (light irradiation region) on the upper surface of the substrate W.

As shown in fig. 3, the stage 42 includes: an object arrangement region 42A in which a substrate W as an object irradiated with light by the light irradiation unit 18 is arranged; and a position calibration area 42B for calibrating the position of the light irradiated by the light irradiation section 18.

The target placement area 42A places the substrate W at a predetermined position in the target placement area 42A. Thereby, the positional relationship between the stage 42 and the substrate W is predetermined. In the position calibration region 42B, the position of the light irradiated from the light irradiation section 18 into the position calibration region 42B is detected by the detection section 62 (see fig. 2). In the position calibration area 42B, before the substrate W in the target arrangement area 42A is subjected to the photo-processing treatment, the correspondence between the set value of the direction of the light irradiated from the light irradiation section 18 and the irradiation position of the detected light is calibrated.

At least a part of the position alignment region 42B is provided with a light transmitting portion 142 that transmits light. The light transmitting portion 142 is made of a glass material (SiO) ₂ ) Or a transparent material such as a 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 alignment region 42B. The light irradiated from the light irradiation section 18 to the light transmission section 142 is transmitted from the upper surface to the lower surface of the stage 42.

The light-transmitting portion 142 is provided at least partially with at least one (two in fig. 3) scattering portion 142A. The scattering portion 142A is made of a transparent material, and reflects or transmits irradiated light while scattering it. The position where the scattering portion 142A is provided is a specific position on the stage 42. That is, the position of the scattering portion 142A is predetermined over the entire stage 42. In fig. 3, the scattering portions 142A are disposed at the ends of the light irradiation region of the light irradiation portion 18 in the X-axis direction, but the positions at which the scattering portions 142A are disposed are not limited to the ends of the light irradiation region of the light irradiation portion 18 as long as they are determined positions on the stage 42. The scattering portion 142A has a property of scattering incident light, and is obtained by, for example, sand blasting a glass material or sanding using hydrofluoric acid or the like. In fig. 3, each scattering portion 142A is formed on the upper surface of the transparent portion 142, but at least one scattering portion 142A may be formed on the lower surface of the transparent portion 142.

In the case shown in fig. 3, the object arrangement region 42A and the position calibration region 42B are separate regions, but at least a part of these regions may overlap. That is, the light-transmitting portion 142 may be provided in a region where at least a part of the substrate W is disposed. In this case, for example, the position of the light irradiated from the light irradiation section 18 may be calibrated at a position where the substrate W is disposed in a state where the substrate W is not disposed.

The light-transmitting portion 142 may have a scattering portion 142A formed over the entire range thereof. That is, the light may be scattered over the entire area of the light transmission portion 142 so that there is no portion through which only light passes.

In fig. 3, the light transmitting portion 142 is provided to extend in the X axis direction, and the scattering portion 142A is provided at each end in the X axis direction, but the light transmitting portion 142 may be divided into a plurality of portions in the X axis direction. However, in the case where the plurality of scattering portions 142A are provided on the transparent portion 142 integrally formed (that is, in the case shown in fig. 3), the transparent portion 142 can be attached (fitted in the case of fig. 3) to the stage 42 while maintaining the positional accuracy between the plurality of scattering portions 142A when the transparent portion 142 is made of a transparent material. Therefore, since the scattering portions 142A are not displaced when mounted on the stage 42, the accuracy of the calibration using the plurality of scattering portions 142A can be kept high.

Fig. 4 is a cross-sectional view mainly illustrating an example of the structures of the light irradiation section 18 and the stage 42 in the structure illustrated in fig. 2. As illustrated in fig. 4, the light irradiation unit 18 includes: a scanner 18A such as a galvanometer mirror or a polygon mirror for controlling the direction of the irradiated light in the X axis direction or the Y axis direction; and a condenser lens 18B for condensing light from a light source not shown. In fig. 4, the light irradiated via the condensing lens 18B and further via the irradiation window 20 formed of quartz is, for example, a laser light 18C. The laser beam 18C can scan the substrate W placed on the upper surface of the stage 42 in the X-axis direction by the control of the scanner 18A. Here, the light irradiation section 18 is preferably capable of controlling light in the X-axis direction and the Y-axis direction, but the light irradiation section 18 may also be capable of controlling light in either the X-axis direction or the Y-axis direction.

The stage 42 includes a light-transmitting portion 142 formed in the position alignment region 42B (see fig. 3), and a scattering portion 142A formed on the upper surface of the light-transmitting portion 142. The laser light 18C irradiated from the light irradiation section 18 may be scanned in a range reaching at least the scattering section 142A in the X-axis direction.

A detector 62 for detecting light is disposed below the stage 42. The detection unit 62 includes: a condensing unit 62A that condenses light in the vacuum chamber 12; an optical fiber 62B that transmits the light condensed by the condensing unit 62A to the outside of the vacuum chamber 12; and a photodetector 62C for detecting light transmitted to the outside of the vacuum chamber 12 through the optical fiber 62B. Since the photodetector 62C is disposed outside the vacuum chamber 12, intrusion of gas that can be emitted from the photodetector 62C into the vacuum chamber 12 can be suppressed.

Fig. 5 and 6 are schematic diagrams illustrating the structure and action of the convergence unit 62A. As illustrated in fig. 5 and 6, the condensing unit 62A includes a condensing lens 162, and the condensing lens 162 condenses the light incident from the light irradiation unit 18 (see fig. 4) on the optical axis of the light.

In the case shown in fig. 5, the laser light 18C (parallel light) incident from the light irradiation section 18 (see fig. 4) reaches the condensing unit 62A only through the light transmitting section 142 on the stage 42. On the other hand, in the case shown in fig. 6, the laser light 18C incident from the light irradiation section 18 (see fig. 4) passes through the scattering section 142A and the light transmission section 142 on the stage 42 and reaches the condensing unit 62A. In fig. 6, the laser light 18C passes through the scattering portion 142A and the light transmitting portion 142, but the laser light 18C may pass through only the scattering portion 142A.

In the case shown in fig. 5, the laser light 18C that has passed through the translucent portion 142 other than the scattering portion 142A reaches the condensing unit 62A so that the irradiation range and direction of the light do not change significantly. Most of the laser light 18C is then condensed by the condensing lens 162 in the condensing unit 62A, and enters the optical fiber 62B disposed at the condensing position of the condensing lens 162.

On the other hand, in the case shown in fig. 6, the laser light 18C that has passed through the scattering section 142A in the light transmitting section 142 scatters light when passing through the scattering section 142A. Then, the laser light 18C reaches the condensing unit 62A in a state where the irradiation range of the laser light 18C is expanded by the scattered light (sand portion in fig. 6). The laser light 18C is condensed by the condensing lens 162 in the condensing unit 62A.

At this time, the laser light 18C whose irradiation range is expanded by the scattering of the light in the scattering section 142A includes many components other than the parallel light, and at least a part of the components are not condensed at the condensing position of the condenser lens 162. Thereby, only a part of the laser light 18C other than the laser light 18C not condensed to the condensed position reaches the optical fiber 62B.

As described above, most of the laser light 18C irradiated onto the upper surface of the stage 42 passes through the light transmitting portion 142 other than the scattering portion 142A, and is condensed by the condensing lens 162 to reach the optical fiber 62B, and only a part of the laser light passes through the scattering portion 142A of the light transmitting portion 142, and is condensed by the condensing lens 162 to reach the optical fiber 62B. Then, the light having reached the optical fiber 62B is detected by the photodetectors 62C (see fig. 4).

Thus, the amount of laser light 18C detected by the detector 62 (see fig. 4) differs between the case where the laser light 18C is irradiated to the translucent portion 142 other than the scattering portion 142A and the case where the laser light is irradiated to the scattering portion 142A. Therefore, based on the light amount value output from the photodetector 62C, the control section 22 can set the timing at which the detected light amount changes to the timing at which the light irradiates the boundary of the transparent section 142 where the scattering section 142A is formed. The control unit 22 can adjust the position of the irradiated light by associating the set value of the scanner 18A (see fig. 4) at that timing with the position (specifically, the boundary position) of the scattering unit 142A. Accordingly, in the subsequent step, when the substrate W disposed on the upper surface of the stage 42 is subjected to the optical processing, the position of the light irradiated from the light irradiation unit 18 can be accurately positioned by the control of the control unit 22.

Further, since the light transmitting portion 142 to which light is applied by the light applying portion 18 is made of a transparent material, even when light of high intensity is repeatedly applied to the light transmitting portion 142 in order to calibrate the position of the light applied by the light applying portion 18, damage to the target (that is, the light transmitting portion 142) to which light is applied in order to calibrate can be suppressed.

< shape of scattering section >

Fig. 7 is a plan view showing an example of the shape of the scattering portion 142A. As illustrated in fig. 7, the scattering portion 142A is provided on the upper surface of the stage 42 (see fig. 3 and 4) so as to extend in the X-axis direction and the Y-axis direction, and may have a shape (butterfly shape) in which two triangles are arranged to face each other and one vertex thereof is connected to each other, for example, in a plan view. With such a shape, the width of the scattering portion 142A in the X axis direction (the total width of the formed regions) increases toward the center portion in the Y axis direction. Alternatively, the width of the scattering portion 142A in the Y axis direction decreases toward the center portion in the X axis direction.

Fig. 8 is a diagram showing an example of a detection signal of the photodetector 62C (see fig. 4) obtained when the scattering portion 142A having the shape illustrated in fig. 7 is scanned in the X-axis direction. In the example shown in fig. 8, the light detector 62C detects light at predetermined sampling timings (T1, T2, T3, T4, and T5) and outputs a detection signal S, and the position of the stage 42 (see fig. 3 and 4) in the Y axis direction is changed for each scan. In the detection signal S shown in fig. 8, a black signal indicates a signal having a strong signal intensity (i.e., a signal having a large amount of detected light), and a white signal indicates a signal having a weak signal intensity (i.e., a signal having a small amount of detected light).

When the light irradiated to the butterfly-shaped scattering portion 142A (see fig. 7) is detected by the photodetector 62C, as illustrated in fig. 8, the regions of weak signal intensity are arranged at two locations in the X-axis direction at the end on the Y-axis positive direction side and the end on the Y-axis negative direction side, and therefore the intensity of the detection signal S fluctuates (disperses) around the sampling timing T3 during the period between the sampling timing T1 and the sampling timing T5. On the other hand, in the central portion in the Y axis direction, since the regions with weak signal intensity are continuously arranged in the X axis direction, the intensity of the detection signal S does not fluctuate during the period between the sampling timing T1 and the sampling timing T5.

In this way, the position in the Y axis direction at the time of scanning in which the detection signal S does not fluctuate is known to be the center position in the Y axis direction of the scattering portion 142A. That is, by comparing the fluctuations of the detection signal S in the plurality of scans, the center position of the scattering portion 142A can be specified with high accuracy.

It is also understood that the position in the X-axis direction corresponding to the midpoint of the period in which the intensity of the detection signal S is weakened (including the period in which the intensity is continuously weakened and the period in which the intensity is intermittently weakened) is the center position of the scattering portion 142A in the X-axis direction. That is, when the detection signal S is output at the sampling timings T1 and T5, the sampling timing T3 is the center position.

On the other hand, when the scattering portion (butterfly shape) having a shape rotated by 90 degrees as shown in fig. 7 is scanned in the X-axis direction (this corresponds to the case where the scattering portion having a shape shown in fig. 7 is scanned in the Y-axis direction), the regions having weak signal intensity are continuously arranged in the X-axis direction at the positive Y-axis direction side end and the negative Y-axis direction side end, and the regions having weak signal intensity are arranged in the X-axis direction at the center.

In this way, the position in the Y axis direction when the detection signal S having a weak signal intensity is detected as the shortest scan is the center position in the Y axis direction of the scattering portion. That is, by comparing the time lengths during which the signal intensity is weak in a plurality of scans, the center position of the scattering portion can be specified with high accuracy.

It is also understood that the position in the X-axis direction corresponding to the midpoint of the period in which the detection signal S becomes weak (the sampling timing T3 in the case where the detection signal S is output from the sampling timing T1 to the sampling timing T5) is the center position in the X-axis direction of the scattering portion.

Since the scattering portion has a butterfly shape, the center position of the scattering portion in the X-axis direction or the Y-axis direction can be determined with high accuracy. This enables the position of the light irradiated from the light irradiation unit 18 (see fig. 4) to be aligned with high accuracy.

The shape of the scattering portion is not limited to the shape in which the region formed toward the center portion in the X-axis direction is gradually reduced as shown in fig. 7 and 8, and may be, for example, a shape in which the region formed toward the center portion in the X-axis direction is discontinuously reduced, or a shape in which the region formed toward the center portion in both the X-axis direction and the Y-axis direction is increased. The shape of the outer edge of the scattering portion is not limited to the straight line shown in fig. 7 and 8, and may include a curve at least in part.

< case of providing a plurality of light irradiation units >

Fig. 9 is a cross-sectional view showing an example of a configuration in a case where a plurality of light irradiation sections are provided. As illustrated in fig. 9, the light irradiation device includes a plurality of

light irradiation units

118 and 218.

The light irradiation unit 118 includes: a scanner 118A such as a galvanometer mirror for controlling the direction of the irradiated light in the X-axis direction; and a condenser lens 118B for condensing light from a light source not shown. In fig. 9, the light irradiated through the condensing lens 118B and further through the irradiation window 20A made of quartz or the like is, for example, a laser beam 118C, and the laser beam 118C can scan the substrate W disposed on the upper surface of the stage 42 in the X-axis direction by the control of the scanner 118A.

Similarly, the light irradiation unit 218 includes: a scanner 218A such as a galvanometer mirror for controlling the direction of the irradiated light in the X-axis direction; and a condenser lens 218B for condensing light from a light source not shown. In fig. 9, the light irradiated through the condensing lens 218B and further through the irradiation window 20B made of quartz or the like is, for example, a laser beam 218C, and the laser beam 218C can scan the substrate W disposed on the upper surface of the stage 42 in the X-axis direction by the control of the scanner 218A.

The light irradiation region in the X-axis direction of the light irradiation section 118 is from a position corresponding to the scattering section 142B formed in the light transmission section 142 to a position corresponding to the scattering section 142C formed in the light transmission section 142. On the other hand, the light irradiation region in the X-axis direction of the light irradiation section 118 is from a position corresponding to the scattering section 142C formed in the light transmission section 142 to a position corresponding to the scattering section 142D formed in the light transmission section 142. That is, the scattering section 142C is disposed at a connecting portion between the light irradiation region of the light irradiation section 118 and the light irradiation region of the light irradiation section 218.

The detection unit 62 is disposed below the stage 42 at positions corresponding to the scattering portion 142B, the scattering portion 142C, and the scattering portion 142D, respectively. The condensing unit 62A in each detection portion 62 is disposed on the optical axis of the light incident from the corresponding light irradiation portion.

By arranging the scattering section 142B, the scattering section 142C, and the scattering section 142D in this way, the connection portion between the light irradiation region of the light irradiation section 118 and the light irradiation region of the light irradiation section 218 is positioned by the common scattering section 142C, and therefore, a positional shift between the two light irradiation regions can be suppressed.

< effects produced by the above-described embodiments >

Next, an example of the effects produced by the above-described embodiments is shown. In the following description, the effect is described based on the specific configuration exemplified in the above-described embodiment, but may be replaced with another specific configuration exemplified in the present specification within a range in which the similar effect is produced. That is, in the following description, for convenience, only one of the corresponding specific configurations may be described as a representative, but the specific configuration described as a representative may be replaced with another corresponding specific configuration.

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

According to such a configuration, since the scattering portion 142A to which light is applied is made of a transparent material, even when light of high intensity such as laser light is applied, damage to the portion (scattering portion 142A) to which light is applied can be reduced. Therefore, the positional accuracy of the light detected by the detection unit 62 is not easily degraded. Further, by detecting both the transmitted light that has passed through only the light transmitting portion 142 and the scattered light that has passed through the scattering portion 142A by the detection portion 62, a sufficient amount of light can be obtained that maintains detection accuracy. Further, since the irradiation range of the light scattered by the scattering portion 142A is wider than that of the light transmitted through the transparent portion 142, the amount of light incident on the optical fiber 62B is reduced as a whole. Thus, it is possible to determine whether the light detected by the detection portion 62 is the light transmitted through the light transmitting portion 142 or the light 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 or not the scattering portion 142A is disposed at the position of the upper surface of the stage 42 irradiated with the light. That is, the position of at least one of the light transmitting portion 142 and the scattering portion 142A can be specified.

Further, even when another structure exemplified in this specification is appropriately added to the above-described structure, that is, when another structure in this specification which is not mentioned as the above-described structure is appropriately added, the same effect can be produced.

Further, according to the above-described embodiment, the control unit 22 determines the position of the boundary between the light transmitting portion 142 and the scattering portion 142A based on the difference in the amount of light detected. With this configuration, the position at which the detected light amount changes can be determined as the position of the boundary between the light transmitting portion 142 and the scattering portion 142A based on the difference between the light amount of the transmitted light and the light amount of the scattered light.

In addition, according to the above-described embodiment, the scattering portion 142A has a butterfly shape in which one vertex of two triangles is connected to each other when the stage 42 is viewed in plan. With such a configuration, it is understood that the middle point of the period during which the detection signal S does not fluctuate or the intensity of the detection signal S becomes weak is the center position of the scattering portion 142A. That is, the center position of the scattering portion 142A can be determined with high accuracy by comparing the intensities of the detection signal S detected in a plurality of scans.

In addition, according to the above-described embodiment, the light irradiated from the light irradiation section 18 is laser light. With such a configuration, even when high-intensity light such as laser light is irradiated, damage to the scattering portion 142A can be reduced.

Further, according to the above-described embodiment, the detection unit 62 includes the condenser lens 162. The condensing lens 162 condenses at least one of the light transmitted through the light transmitting portion 142 and the light scattered by the scattering portion 142A. According to such a structure, it is easy to secure the light amount for maintaining the detection accuracy by the convergence.

Further, according to the above-described embodiment, the light irradiation device includes the cavity in which the stage 42 is incorporated. The chamber corresponds to, for example, the vacuum chamber 12. The vacuum chamber 12 is filled with a vacuum or reduced-pressure gas. The detection unit 62 includes an optical fiber 62B and a photodetector 62C. The optical fiber 62B transmits the light condensed by the condensing lens 162 to the outside of the vacuum chamber 12. The photodetector 62C is disposed outside the vacuum chamber 12 and detects light transmitted by the optical fiber 62B. According to such a configuration, since the photodetector 62C in the detection portion 62 is provided outside the vacuum chamber 12, intrusion of the off-gas emitted from the photodetector 62C into the vacuum chamber 12 can be suppressed.

According to the above-described embodiment, in the light irradiation method, light is irradiated to the upper surface of the stage 42 made of a transparent material. The stage 42 is provided with a light-transmitting portion 142 for transmitting light therethrough and at least one 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 scattering portion 142A is detected. Then, the position of at least one of the light transmitting portion 142 and the scattering portion 142A is determined based on the detected light amount.

According to such a configuration, since the scattering portion 142A to which light is applied is made of a transparent material, even when light of high intensity such as laser light is applied, damage to the portion (scattering portion 142A) to which light is applied can be reduced. Therefore, the positional accuracy of the light detected by the detection portion 62 is not easily degraded. Further, by detecting both the transmitted light that has passed through only the light transmitting portion 142 and the scattered light that has passed through the scattering portion 142A by the detection portion 62, a sufficient amount of light can be obtained that maintains detection accuracy. Further, it is possible to determine whether the light detected by the detection portion 62 is the light transmitted through the light transmitting portion 142 or the light scattered by the scattering portion 142A based on the difference between the amount of transmitted light and the amount of scattered light. Therefore, the position of at least one of the light transmitting portion 142 and the scattering portion 142A can be specified.

In addition, the same effects can be produced also in the case where the other structures exemplified in the present specification are appropriately added to the above-described structure, that is, in the case where the other structures in the present specification which are not mentioned as the above-described structure are appropriately added.

< modification of the above-described embodiment >

In the above-described embodiments, the material, size, shape, relative arrangement, conditions for implementation, and the like of each structural member are described, but the present invention is not limited to these.

Therefore, innumerable modifications and equivalents not illustrated can be conceived within the technical scope disclosed in the present specification. For example, the case where at least one structural member is deformed, added, or omitted is included.

In the above-described embodiments, when a material name or the like is described in a manner not particularly specified, other additives, for example, an alloy or the like may be contained in the material as long as no contradiction occurs.

Claims

1. A light irradiation device, in which,

the disclosed device is provided with:

an object stage, at least a portion of which is formed of a transparent material; and

at least one light irradiation section for irradiating light to an upper surface of the stage,

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 device further includes:

a detection unit for detecting at least one of the light transmitted through the light transmission unit and the light scattered by the scattering unit; and

and a determination unit configured to determine a position of at least one of the light transmission unit and the scattering unit based on the detected light amount.

2. The light irradiation apparatus according to claim 1,

the specifying unit specifies a position of a boundary between the light transmitting portion and the scattering portion based on a difference in the detected light amount of the light.

3. The light irradiation apparatus according to claim 1 or 2,

the scattering portion has a butterfly shape in which one vertexes of two triangles are connected to each other when the stage is viewed in a plan view.

4. The light irradiation apparatus according to claim 1 or 2,

the light irradiated from the light irradiation section is laser light.

5. The light irradiation apparatus according to claim 1 or 2,

the detection unit includes a condensing lens for condensing at least one of the light transmitted through the light transmission unit and the light scattered by the scattering unit.

6. The light irradiation apparatus according to claim 5,

the light irradiation device further comprises a cavity in which the stage is disposed,

the cavity is in vacuum or reduced pressure gas environment,

the detection unit further includes:

an optical fiber transmitting the light converged by the converging lens to an outside of the cavity; and

a light detector disposed outside the cavity and detecting the light transmitted by the optical fiber.

7. A method of irradiating light, wherein,

comprises a step of irradiating the upper surface of a stage made of a transparent material with light,

the light irradiation method further includes:

detecting at least one of the light transmitted through the light transmitting portion and the light scattered by the scattering portion; and

and determining a position of at least one of the light transmitting portion and the scattering portion based on the detected light amount.