JP2023021536A - Light detection device and light irradiation device - Google Patents

Abstract

To provide a technique for suppressing lowering of light detection accuracy by suppressing decrease in a light quantity caused by propagation.SOLUTION: A light detection device for detecting light irradiated from a light irradiation part includes: a propagation member for propagating light irradiated from the light irradiation part; and a light detector for detecting the light propagated by the propagation member, wherein a plurality of first scattering parts for scattering the light are discretely provided on the propagation member.SELECTED DRAWING: Figure 4

Description

The technology disclosed in this specification relates to technology for detecting emitted light.

2. Description of the Related Art Conventionally, an optical processing technique for processing an object by light irradiation such as laser light irradiation has been used (see Patent Document 1, for example).

Japanese Patent Application Laid-Open No. 2006-272430

When the irradiated light is detected through the propagation member as described above, the amount of detected light may be greatly reduced due to diffusion in the propagation process. In such a case, the accuracy of light detection is lowered due to the lack of light quantity.

The technology disclosed in the specification of the present application has been made in view of the problems described above, and provides a method for suppressing a decrease in light detection accuracy by suppressing a decrease in the amount of light caused by propagation. Technology.

A photodetector that is a first aspect of the technology disclosed in the specification of the present application is a photodetector that detects light irradiated from a light irradiation unit, and propagates the light irradiated from the light irradiation unit. and a photodetector for detecting the light propagated by the propagation member, wherein the propagation member has a plurality of discrete first scattering portions for scattering the light be provided.

A photodetector, which is a second aspect of the technology disclosed in this specification, relates to the photodetector, which is a first aspect, wherein the photodetector faces a longitudinal end of the propagation member. and the plurality of first scattering portions are discretely arranged along the longitudinal direction of the propagation member.

A photodetection device that is a third aspect of the technology disclosed in this specification relates to the photodetection device that is the first or second aspect, wherein the propagation member has an end facing the photodetector. and the width of a second scattering portion, which is one of the plurality of first scattering portions, is provided at a position closer to the end portion than the second scattering portion. It is equal to or greater than the width of the third scattering portion.

A photodetection device according to a fourth aspect of the technology disclosed in this specification relates to the photodetection device according to any one of the first to third aspects, further comprising a stage, the light irradiation unit irradiates the upper surface of the stage with the light, and at least a part of the stage is provided with at least one fourth scattering section for scattering the light, and the fourth scattering section is transparent made of a flexible material, the propagation member propagates the light incident through the fourth scattering section.

The photodetector, which is the fifth aspect of the technology disclosed in this specification, relates to the photodetector, which is the fourth aspect, wherein each of the first scattering portions is a portion of the fourth scattering portion. arranged corresponding to the position.

The photodetector according to the sixth aspect of the technology disclosed in the present specification is related to the photodetector according to the fourth or fifth aspect, and detects the incident light through the fourth scattering section. further comprising: a condenser lens for condensing light; and a light blocking plate arranged at a position farther from the fourth scattering unit than the condenser lens and at a light condensing position of the condenser lens, A member propagates the light condensed by the condensing lens.

A photodetector according to a seventh aspect of the technology disclosed in this specification relates to the photodetector according to any one of the first to sixth aspects, wherein the plurality of first scattering units comprises , formed by blasting on the surface of the propagating member.

A photodetector according to an eighth aspect of the technology disclosed in this specification relates to the photodetector according to any one aspect of the first to sixth aspects, wherein the plurality of first scattering units comprises and a reflective film applied to the lower surface of the propagation member.

A light detection device according to a ninth aspect of the technology disclosed in this specification relates to the light detection device according to any one of the first to eighth aspects, wherein the light emitted from the light irradiation unit The light is laser light.

A photodetector according to a tenth aspect of the technology disclosed in this specification relates to the photodetector according to any one of the first to ninth aspects, and includes a chamber containing the propagation member. Further, the photodetector detects the light propagated by the propagation member outside the chamber.

A light irradiation device according to an eleventh aspect of the technology disclosed in this specification includes at least one light irradiation unit for irradiating light, and a light detection device according to any one of the first to tenth aspects. and a device.

According to at least the first aspect of the technology disclosed in the specification of the present application, it is possible to suppress a decrease in the amount of light to be propagated by suppressing excessive diffusion while light is propagating through the propagation member. can. As a result, deterioration in photodetection accuracy can be suppressed.

Also, the objects, features, aspects, and advantages associated with the technology disclosed herein will become more apparent from the detailed description and accompanying drawings presented below.

It is a perspective view which shows roughly the example of a structure of the light irradiation apparatus regarding embodiment. 2 is a cross-sectional view showing an example of the internal configuration of a vacuum chamber and the peripheral configuration of the light irradiation device according to the embodiment; FIG. FIG. 3 is a perspective view mainly showing a light irradiation unit and a stage in the configuration shown in the example of FIG. 2; FIG. 3 is a cross-sectional view mainly showing an example of a configuration of a light irradiation unit and a stage among the configurations illustrated in FIG. 2; It is a figure which shows the example of the formation width of a scattering part. It is a figure which shows the example of the formation width of a scattering part. FIG. 4 is a schematic diagram showing a light collection unit and a transparent rod in the detection section; FIG. 4 is a schematic diagram showing a light collection unit and a transparent rod in the detection section; It is a figure which shows the mode of propagation of the light in a transparent rod. It is a figure which shows the mode of propagation of the light in a transparent rod. FIG. 4 is a cross-sectional view schematically showing an example of the configuration of a transparent rod;

Embodiments will be described below with reference to the attached drawings. In the following embodiments, detailed features and the like are also shown for technical explanation, but they are examples, and not all of them are necessarily essential features for enabling the embodiments.

It should be noted that the drawings are shown schematically, and for the convenience of explanation, some omissions or simplifications of the configuration may be made in the drawings as appropriate. In addition, the mutual relationship of sizes and positions of configurations shown in different drawings is not necessarily described accurately and can be changed as appropriate. Also, in drawings such as plan views that are not cross-sectional views, hatching may be added to facilitate understanding of the contents of the embodiments.

In addition, in the description given below, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, a detailed description thereof may be omitted to avoid duplication.

Also, in the descriptions in this specification, when a component is described as “comprising,” “including,” or “having,” unless otherwise specified, it is an exclusive term that excludes other components. not an expression.

In addition, even if ordinal numbers such as “first” or “second” are used in the description given in this specification, these terms are used to understand the content of the embodiments. They are used for the sake of convenience, and the subject matter of the embodiments is not limited to the order or the like that can occur with these ordinal numbers.

In addition, in the descriptions given in the specification of the present application, expressions such as “… positive direction of axis” or “… negative direction of axis” refer to the direction along the arrow of the illustrated , the direction opposite to the arrow is the negative direction.

Also, in the descriptions provided herein, specific positions or orientations such as "top", "bottom", "left", "right", "side", "bottom", "front" or "back" are used for convenience in order to facilitate understanding of the content of the embodiments, and may be used when the embodiments are actually implemented. is independent of the position or orientation of

In addition, in the description given in this specification, when “the upper surface of” or “the lower surface of ...” is described, in addition to the upper surface itself or the lower surface itself of the target component, the target component A state in which other constituent elements are formed on the upper or lower surface of the is also included. That is, for example, when "B provided on the upper surface of A" is described, it does not prevent another component "C" to be interposed between A and B.

In addition, in the descriptions described in the specification of the present application, expressions indicating shapes, such as “prism shape” or “cylindrical shape”, unless otherwise specified, strictly indicate that shape and tolerance Alternatively, it includes the case where unevenness or chamfering is formed within the range where the same degree of function can be obtained.

<Embodiment>
A photodetector and a light irradiation device according to the present embodiment will be described below. In the following embodiments, as an example, a light irradiation apparatus in which the inside of the chamber is in a vacuum or a reduced pressure atmosphere is described, but the same can be applied even when the inside of the chamber is not in a vacuum.

<Regarding the configuration of the light irradiation device>
FIG. 1 is a perspective view schematically showing an example of the configuration of a light irradiation device 1 according to this embodiment. In FIG. 1, the illustration of the chamber frame that supports the vacuum chamber 12 or the wiring that is actually connected is omitted for the sake of convenience. It should be noted that the "vacuum" in the present embodiment is desirably a high vacuum (for example, 0.00001 Pa) in order to prevent deterioration of the characteristics of the substrate W, but if the degree of vacuum does not reach the high vacuum, shall also include

As an example is shown in FIG. 1, the light irradiation device 1 includes a vacuum chamber 12, an external fixed part 14 such as a granite surface plate, and the vacuum chamber 12 and the external fixed part 14, which are made of, for example, stainless steel. A bellows 16A which is a stretchable member, a light irradiation unit 18 which irradiates light into the vacuum chamber 12, a vacuum pump 21 which reduces the pressure in the vacuum chamber 12 to a vacuum state, and a light irradiation device 1. and a control unit 22 for controlling the driving unit. In the above description, bellows made of stainless steel or the like is shown as an example of the elastic member. An elastic member made of resin or the like may be employed. Further, the shape of the stretchable member may not be a bellows shape like the bellows 16A described above.

The vacuum chamber 12 has a space in which the substrate W is accommodated. The substrate W to be processed includes, for example, a semiconductor wafer, a glass substrate for a liquid crystal display device, a flat panel display (FPD) substrate such as an organic EL (electroluminescence) display device, an optical disk substrate, a magnetic disk substrate, and a magneto-optical substrate. It includes disk substrates, photomask glass substrates, ceramic substrates, field emission display (FED) substrates, solar cell substrates, and the like. The substrate W is, for example, a substrate having a thin film formed on its upper surface.

An opening 12A is formed in the side surface of the vacuum chamber 12 through which the substrate W passes when the substrate W is loaded and unloaded. The opening 12A is appropriately closed when the vacuum chamber 12 is evacuated. Other configurations accommodated inside the vacuum chamber 12 will be described later.

The light irradiation unit 18 irradiates the upper surface of the substrate W housed in the vacuum chamber 12 with light. At this time, the substrate W is aligned in advance by a detection unit or the like, which will be described later. The light irradiation unit 18 ablates the substrate W by irradiating it with laser light, for example. The light irradiator 18 may irradiate light such as an electron beam depending on the purpose of processing. The light irradiation unit 18 irradiates the upper surface of the substrate W accommodated in the vacuum chamber 12 from outside the vacuum chamber 12 through an irradiation window (transparent plate made of quartz or the like) (not shown). Light scans the upper surface of the substrate W by moving the substrate W in the vacuum chamber 12 relative to the light irradiation unit 18 or by controlling the optical system in the light irradiation unit 18 . Further, the light irradiation section 18 is arranged on the upper surface of the mount 24 fixed to the external fixing section 14 .

The control unit 22 includes, for example, a hard disk drive (ie, HDD), a random access memory (ie, RAM), a read only memory (ie, ROM), a flash memory, a volatile Or non-volatile semiconductor memory, magnetic disk, flexible disk, optical disk, compact disk, mini disk or storage device including memory (storage medium) including DVD, for example, the storage device, external CD-ROM, external A processing circuit such as a central processing unit (i.e., CPU) that executes programs stored in a DVD-ROM or an external flash memory, and a mouse, keyboard, touch panel, or various switches , an input device to which information can be input, and an output device, such as a display, a liquid crystal display, or a lamp, to which information can be output.

The control unit 22 controls the output of the light source in the light irradiation unit 18 and the direction in which the light is irradiated, the output control of the vacuum pump 21, and the driving control of each driving unit described later.

FIG. 2 is a cross-sectional view showing an example of the internal configuration and peripheral configuration of the vacuum chamber 12 of the light irradiation device 1 according to this embodiment. As an example is shown in FIG. 2, inside the vacuum chamber 12 are a stage 42 on which the substrate W is placed, and a slider 44 which is movable in the Y-axis direction and supports the stage 42 from below. a base 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 for moving in the axial direction and a lift pin mechanism 52 having lift pins 52A for supporting the substrate W through through holes (not shown here) formed in the stage 42 are provided.

The stage 42 holds the substrate W substantially horizontally while directing the processing surface of the substrate W upward. A detailed configuration of the stage 42 will be described later. The slider 44 that supports 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 processing area of the substrate W in plan view is changed. can be scanned with light. Alternatively, by scanning the light irradiated from the light irradiation unit 18 in the X-axis direction and the Y-axis direction, it is possible to scan the entire processing region of the substrate W with the light in plan view. Note that the lift pin mechanism 52 is fixed to the base 46 .

The linear motor mechanism 50 is fixed to the external fixing part 14 positioned on the side of the vacuum chamber 12 through an opening 12B formed in the side surface of the vacuum chamber 12 . Specifically, linear motor mechanism 50 is fixed to the end of hollow post 14A passing through bellows 16A welded to opening 12B. At this time, wiring and the like connected to the linear motor mechanism 50 are led out of the vacuum chamber 12 through the inside of the columnar member 14A. 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. As shown in FIG. Also, the columnar member 14A does not come into contact with the bellows 16A connected to the side surface of the vacuum chamber 12. As shown in FIG.

The base 46 is fixed to the external fixing part 14 positioned below the vacuum chamber 12 through an opening 12C formed in the bottom surface of the vacuum chamber 12 . Specifically, the base 46 is fixed to the end of the columnar member 14C passing through the bellows 16B welded to the opening 12C. 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. As shown in FIG. Also, the columnar member 14C does not come into contact with the bellows 16B connected to the bottom surface of the vacuum chamber 12. As shown in FIG.

In FIG. 2, the external fixtures 14 are arranged laterally and downwardly of the vacuum chamber 12, but it is not essential that the external fixtures 14 at these positions be continuous, but distributed at these positions. It may be provided as such, or may be provided only at one of the positions. In addition, the vacuum chamber 12 is supported and fixed vertically by a chamber frame (not shown) separately from the bellows 16B.

FIG. 3 is a perspective view mainly showing the light irradiation section 18 and the stage 42 in the configuration shown in FIG. 3 shows a state in which the substrate W is placed on the upper surface of the stage 42. As shown in FIG. 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). Therefore, the light emitted from the light irradiation unit 18 to the upper surface of the stage 42 can form a rectangular irradiation area (light irradiation area) on the upper surface of the substrate W. FIG.

As shown in FIG. 3, the stage 42 calibrates a target placement region 42A in which the substrate W to be irradiated with light by the light irradiation unit 18 is placed, and the position of the light irradiated by the light irradiation unit 18. A position calibration area 42B is provided as an area for performing calibration.

The target placement area 42A places the substrate W at a specific position within the target placement area 42A. Thereby, the positional relationship between the stage 42 and the substrate W is specified in advance. In the position calibration area 42B, the position of the light irradiated from the light irradiation section 18 into the position calibration area 42B is detected. Then, in the position calibration region 42B, prior to the optical processing of the substrate W in the target placement region 42A, the correspondence relationship between the set value of the direction of the light irradiated from the light irradiation unit 18 and the detected irradiation position of the light. is calibrated.

At least part of the position calibration region 42B is provided with a light transmitting portion 142 that transmits light. Translucent portion 142 is made of a glass material such as quartz (SiO ₂ ) or a transparent material such as transparent resin (for example, silicon resin). The translucent part 142 is provided from the upper surface to the lower surface of the stage 42 corresponding to the position calibration area 42B. The light irradiated from the light irradiation section 18 to the light transmitting section 142 is transmitted from the upper surface to the lower surface of the stage 42 .

The translucent portion 142 is provided with, for example, four scattering portions 142A. Note that the number of scattering portions 142A is not limited to four. The scattering section 142A is made of a transparent material, and scatters and reflects or transmits the irradiated light. The position where the scattering section 142A is provided is a specific position on the stage 42 . That is, the position of the scattering portion 142A on the entire stage 42 is specified in advance. In FIG. 3, each scattering section 142A is arranged at the end of the light irradiation region of the light irradiation section 18 in the X-axis direction, but the position where the scattering section 142A is arranged is a specific position on the stage 42. It is not limited to the end portion of the light irradiation area of the light irradiation section 18 as long as it is sufficient. The scattering portion 142A has a property of scattering incident light, and can be obtained, for example, by subjecting a glass material to blasting or frosting using hydrofluoric acid or the like. 3, each scattering portion 142A is formed on the upper surface of the translucent portion 142, but at least one scattering portion 142A may be formed on the lower surface of the translucent portion 142. FIG.

In the case shown in FIG. 3, the target placement area 42A and the position calibration area 42B are separate areas, but these areas may overlap at least partially. That is, the translucent part 142 may be provided in at least a part of the area where the substrate W is arranged. In such a case, for example, the position of the light irradiated from the light irradiation unit 18 may be calibrated at the position where the substrate W is to be arranged, while the substrate W is not arranged.

Further, the translucent portion 142 may have a scattering portion 142A formed over its entire range. In other words, there may be no portion where only light is transmitted, and light scattering may occur over the entire range of the light transmitting portion 142 .

In FIG. 3, the translucent portions 142 are provided extending in the X-axis direction, and scattering portions 142A are provided at respective ends in the X-axis direction. It may be divided into parts. However, when a plurality of scattering portions 142A are provided in the integrally formed translucent portion 142 (that is, the case shown in FIG. 3), when the translucent portion 142 is manufactured with a transparent material, The light transmitting portion 142 can be attached (fitted in in the case of FIG. 3) to the stage 42 while maintaining the positional accuracy among the plurality of scattering portions 142A. Therefore, since there is no positional deviation between the scattering portions 142A when attached to the stage 42, it is possible to maintain high accuracy of calibration performed using the plurality of scattering portions 142A.

FIG. 4 is a sectional view mainly showing an example of the configuration of the light irradiation section 18 and the stage 42 among the configurations shown in FIG. As an example is shown in FIG. 4, the light irradiation unit 18 includes a scanner 18A such as a galvanometer mirror or a polygon mirror that controls the direction of the light to be irradiated in the X-axis direction and the Y-axis direction, and light from a light source (not shown). and a condensing lens 18B for condensing the light. In FIG. 4, the light irradiated through the condensing lens 18B and the irradiation window 20 made of quartz or the like is, for example, 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 and the Y-axis direction under the control of the scanner 18A. Here, the light irradiation unit 18 is preferably capable of controlling light in the X-axis direction and the Y-axis direction, but the light irradiation unit 18 can control light in either the X-axis direction or the Y-axis direction. There may be.

The stage 42 includes a light transmitting portion 142 formed in the position calibration region 42B (see FIG. 3) and a scattering portion 142A formed on the upper surface of the light transmitting portion 142. As shown in FIG. The laser beam 18C emitted from the light irradiation unit 18 can scan in the X-axis direction at least within a range reaching the scattering unit 142A.

A detector 62 for detecting light is arranged below the stage 42 . The detection unit 62 includes a light collecting unit 62A that collects light within the vacuum chamber 12, a transparent rod 62D that propagates the light collected by the light collecting unit 62A, and the transparent rods 62D that are arranged discretely in the X-axis direction. A plurality of scattering portions 166, a fiber 62B for emitting the light propagating in the transparent rod 62D from the transparent rod 62D, a condenser lens 62E for condensing the light emitted from the fiber 62B, and the condenser lens 62E. and a photodetector 62C for detecting emitted light outside the vacuum chamber 12 through a transparent window 20A provided in the housing of the vacuum chamber 12. A photodetector can be configured by including the transparent rod 62D and the photodetector 62C.

The plurality of scattering portions 166 include a scattering portion 166A extending in the Y-axis direction and a scattering portion 166B extending longer than the scattering portion 166A in the Y-axis direction. In FIG. 4, two scattering portions 166A are arranged near the photodetector 62C, and two scattering portions 166B are arranged far from the photodetector 62C.

In FIG. 4, two scattering portions 166A are arranged in a row, and two scattering portions 166B are arranged in a row. That is, the width of the scattering portion 166 in the Y-axis direction increases stepwise (discontinuously) from the side closer to the photodetector 62C. However, for example, four scattering portions 166 each having a different width in the Y-axis direction are arranged in a direction away from the photodetector 62C, and their widths in the Y-axis direction are continuous according to the distance from the photodetector 62C. may be as wide as In other words, the width of the scattering portion 166 farther from the photodetector 62C should be equal to or greater than the width of the scattering portion 166 near the photodetector 62C.

Further, the scattering portion 166 shown in FIG. 4 is formed extending in the Y-axis direction (depth direction on the paper surface), but the scattering portion 166 is formed extending in the X-axis direction (horizontal direction on the paper surface), The X-axis direction width of the scattering portion 166 located near the detector 62C may be greater than or equal to the X-axis direction width of the scattering portion 166 located far from the photodetector 62C. In other words, if the direction connecting the scattering portion 166 and the photodetector 62C is the first direction, the width of the scattering portion 166 that changes according to the distance from the photodetector 62C is the width in the first direction. It may be the width in the direction orthogonal to the first direction.

FIG. 5 is a diagram showing an example of the formation width of the scattering portion 166A. Also, FIG. 6 is a diagram showing an example of the formation width of the scattering portion 166B. As an example is shown in FIG. 5, when the transparent rod 62D has a cylindrical shape, the scattering portion 166A is formed extending along the circumferential direction of the transparent rod 62D. Further, as shown in FIG. 6, when the transparent rod 62D has a cylindrical shape, the scattering portion 166B is also formed to extend along the circumferential direction of the transparent rod 62D. Here, since the width in the Y-axis direction of the scattering portion 166B is wider than the width of the scattering portion 166A, the length in the circumferential direction is also longer.

The transparent window 20A in FIG. 4 is made of, for example, a glass material or a transparent material such as a transparent resin.

Since the photodetector 62</b>C in FIG. 4 is arranged outside the vacuum chamber 12 , it is possible to suppress the intrusion into the vacuum chamber 12 of gas that may be emitted from the photodetector 62</b>C.

7 and 8 are schematic diagrams showing the condensing unit 62A and the transparent rod 62D in the detection section. As shown in FIGS. 7 and 8, the light collecting unit 62A includes a light collecting lens 162 for collecting the light on the optical axis of the light incident from the light irradiation section 18 in FIG. and a light shielding plate 164 arranged on the optical axis of the light incident from the irradiation unit 18 and downstream of the light path from the condenser lens 162 (that is, on the Z-axis negative direction side in FIGS. 7 and 8). . The light blocking plate 164 is a plate-like member that blocks incident light, and is arranged at a light condensing position of the condensing lens 162 at a position farther from the light transmitting portion 142 than the condensing lens 162 .

Also, as examples are shown in FIGS. 7 and 8, the transparent rod 62D is made of a glass material such as quartz (SiO ₂ ) or a transparent material such as transparent resin (for example, silicon resin). Also, the transparent rod 62D is, for example, a cylindrical rod member, and is formed to extend in a plane (that is, the XY plane) along the surface of the stage 42 in FIG. If the transparent rod 62D has a cylindrical shape, when the light condensed by the light condensing unit 62A is incident on the transparent rod 62D, the total reflection condition is easily satisfied within the transparent rod 62D, and the light can be efficiently propagated. can be done. However, the shape of the transparent rod 62D is not limited to a columnar shape, and may be, for example, a prismatic shape. Further, in the present embodiment, the transparent rod 62D has a bar shape, but the transparent rod 62D may have a surface shape corresponding to the entire surface of the stage 42, for example.

The transparent rod 62D is arranged at a conjugate position with the scattering section 142A with the condenser lens 162 as a reference in the Z-axis direction.

Also, the transparent rod 62D may be arranged in a range that overlaps at least the scattering portion 142A in plan view (for example, a range that includes the scattering portion 142A in plan view). With such an arrangement, the light scattered by the scattering section 142A and further condensed by the condensing unit 62A is efficiently incident on the transparent rod 62D and propagated.

A plurality of scattering portions 166 are provided on the lower surface of the transparent rod 62D. Each scattering portion 166 scatters and reflects or transmits the irradiated light. Each scattering portion 166 is obtained, for example, by subjecting a glass material to blasting or frosting using hydrofluoric acid or the like.

Each scattering portion 166 is arranged in a range that overlaps at least the scattering portion 142A (for example, a range that includes the scattering portion 142A in plan view) when viewed in plan, ie, in the light incident direction. Each scattering portion 166 may be provided inside or on the upper surface of the transparent rod 62D.

In the case shown in FIG. 7, the laser light 18C (parallel light) incident from the light irradiation section 18 (see FIG. 4) passes only through the light transmitting section 142 of the stage 42 and reaches the condensing unit 62A. ing. On the other hand, in the case shown in FIG. 8, the laser beam 18C incident from the light irradiation section 18 (see FIG. 4) passes through the scattering section 142A and the translucent section 142 in the stage 42 and reaches the condensing unit 62A. have reached. Although the laser beam 18C passes through the scattering portion 142A and the translucent portion 142 in FIG. 8, the laser beam 18C may pass through only the scattering portion 142A.

In the case shown in FIG. 7, the laser beam 18C passing through the translucent portion 142 other than the scattering portion 142A reaches the condensing unit 62A without a large change in the irradiation range and direction of the light. Then, the laser beam 18C is condensed by the condensing lens 162 in the condensing unit 62A and enters the light blocking plate 164 arranged at the condensing position of the condensing lens 162 . Since light is blocked by the light shielding plate 164, the laser light 18C does not reach the transparent rod 62D located further downstream than the light shielding plate 164 in the light path along the optical axis of the laser light 18C.

On the other hand, in the case shown in FIG. 8, the laser light 18C passing through the scattering portion 142A in the translucent portion 142 undergoes light scattering when passing through the scattering portion 142A. Then, the laser beam 18C reaches the light collecting unit 62A in a state in which the irradiation range of the laser beam 18C is expanded by the scattered light (the sandy portion in FIG. 8). Then, the laser beam 18C is condensed by the condensing lens 162 in the condensing unit 62A.

At this time, the laser beam 18C whose irradiation range is expanded due to the scattering of light in the scattering portion 142A contains many components that are not parallel light, and at least some of the components are at the condensing position of the condensing lens 162. Not focused. Therefore, the light blocking plate 164 arranged at the condensing position of the condensing lens 162 blocks only part of the laser beam 18C. In other words, a portion of the laser light 18C not blocked by the light shielding plate 164, that is, the laser light 18C scattered light arrives.

Then, the laser beam 18C that has entered the transparent rod 62D is scattered in the scattering portion 166. As shown in FIG. A portion of the scattered laser light 18C is reflected within the transparent rod 62D and propagates to reach the fiber 62B connected to the end of the transparent rod 62D.

As described above, when the laser beam 18C irradiated onto the upper surface of the stage 42 is incident on the portion of the translucent portion 142 where the scattering portion 142A is formed, it becomes transparent after being condensed by the condensing unit 62A. Reach rod 62D. The light reaching the transparent rod 62D propagates through the transparent rod 62D and further through the fiber 62B connected to the end of the transparent rod 62D, and then is collected by the condenser lens 62E and detected by the photodetector 62C. be done. Therefore, when the scattering portion 142A is irradiated with the laser beam 18C, the detector 62 can detect the scattered light of the laser beam 18C. The position of the irradiated light can be calibrated so as to correspond to the position of 142A. As a result, when the substrate W placed on the top surface of the stage 42 is optically processed in a later step, the position of the light emitted from the light irradiation unit 18 (see FIG. 4) can be aligned with high accuracy. can be done.

In addition, since the light-transmitting portion 142 and the transparent rod 62D to which the light is irradiated by the light irradiation portion 18 (see FIG. 4) are made of a transparent material, the light is irradiated by the light irradiation portion 18 (see FIG. 4). Even if relatively high-intensity light is repeatedly applied to the light-transmitting portion 142 and the transparent rod 62D to calibrate the position of the light, the target (i.e., the light-transmitting target) to which the light is irradiated for calibration. Damage to the portion 142 and the transparent rod 62D) can be suppressed.

In addition, the light detected by the detection unit 62 is scattered light, and is not transmitted light that has passed through the light transmission unit 142 without being scattered. Damage caused by the light at 62 can be suppressed.

FIG. 9 is a diagram showing how light propagates through the transparent rod 62D. As an example is shown in FIG. 9, the laser beam 18C incident from the light irradiation section 18 (see FIG. 4) propagates within the transparent rod 62D and reaches the end of the transparent rod 62D. The light propagates through the fiber 62B connected to the end of the transparent rod 62D in the longitudinal direction (X-axis direction), and then condensed by the condensing lens 62E (see FIG. 4). The light is then detected by a photodetector 62C (see FIG. 4) facing the end of the transparent rod 62D through a condenser lens 62E.

As an example is shown in FIG. 9, the scattering portion 166B is formed corresponding to the position where the laser beam 18C is incident, so that the laser beam 18C incident on the transparent rod 62D does not pass through the transparent rod 62D. The light is scattered at the scattering portion 166B and easily propagates through the transparent rod 62D.

Moreover, since the scattering portions 166A and the scattering portions 166B are provided discretely in the longitudinal direction (X-axis direction) of the lower surface of the transparent rod 62D, for example, when the scattering portions are provided on the entire lower surface of the transparent rod 62D, In comparison, laser light 18C propagating within transparent rod 62D has less chance of being scattered during propagation. Therefore, the laser beam 18C easily propagates through the transparent rod 62D while satisfying the total reflection condition, and as a result, it is possible to suppress the decrease in the light amount of the laser beam 18C detected by the photodetector 62C.

FIG. 10 is a diagram showing how light propagates through the transparent rod 62D. In FIG. 10, the incident position of the laser beam 18C incident on the transparent rod 62D is closer to the fiber 62B connected to the photodetector 62C (see FIG. 4) than in FIG.

As an example is shown in FIG. 10, the scattering portion 166A is formed corresponding to the position where the laser beam 18C is incident, so that the laser beam 18C incident on the transparent rod 62D does not pass through the transparent rod 62D. The light is scattered at the scattering portion 166A and easily propagates through the transparent rod 62D.

Here, the width of the scattering portion 166B in the Y-axis direction is wider than the width of the scattering portion 166A in the Y-axis direction. Therefore, the laser beam 18C incident on the position corresponding to the scattering portion 166B as shown in FIG. 9 is more likely than the laser beam 18C incident on the position corresponding to the scattering portion 166A as shown in FIG. The proportion of light incident on the corresponding scattering portion 166 increases, and the light is scattered by the scattering portion 166 and easily propagates through the transparent rod 62D. That is, the laser beam 18C incident at a position farther from the photodetector 62C (see FIG. 4) is more likely to be scattered by the corresponding scattering portion 166 than the laser beam 18C incident at a position closer to the photodetector 62C. , a high amount of light can easily propagate through the transparent rod 62D.

Then, even if the light intensity of the laser beam 18C incident at a position far from the photodetector 62C (see FIG. 4) is reduced due to scattering while propagating in the transparent rod 62D, A difference in the amount of light detected by the photodetector 62C is less likely to occur between the laser beam 18C that has entered the position and the laser beam 18C that has entered a position far from the photodetector 62C. Therefore, it is possible to set a threshold value (a value for distinguishing from noise) for the amount of light to be detected regardless of the incident position of the laser beam 18C. 18C can be effectively detected. As a result, light detection accuracy can be improved.

The scattering portion provided on the transparent rod 62D is not limited to one formed by processing the surface of the transparent rod 62D. may be

If the transparent material is processed like the scattering part 166, damage due to light irradiation is unlikely to occur, and it is possible to suppress outgassing, which is a problem under vacuum (or under reduced pressure). If a reflective film such as a metal film is provided as the scattering portion, the reflectance of the light incident on the transparent rod 62D is improved, so that the propagation efficiency of the light can be improved.

FIG. 11 is a cross-sectional view schematically showing an example of the configuration of the transparent rod 162D. As shown in FIG. 11, the lower surface of the transparent rod 162D is coated with a reflective film 168 as a scattering portion. Reflective film 168 is a metal film made of, for example, alumina (aluminum oxide).

If the reflective film 168 is provided at that location, the light is totally reflected by the reflective film 168 and then propagates through the transparent rod 162D.

<About the effect produced by the embodiment described above>
Next, examples of effects produced by the embodiments described above are shown. In the following description, the effect will be described based on the specific configuration exemplified in the embodiment described above. may be substituted with other specific configurations shown. That is, hereinafter, for convenience, only one of the specific configurations to be associated may be described as a representative, but other specific configurations to which the specific configurations described as representative are associated may be replaced with a similar configuration.

According to the embodiments described above, the photodetection device comprises a propagating member and photodetector 62C. Here, the propagating member corresponds to, for example, at least one of the transparent rod 62D and the transparent rod 162D. The transparent rod 62D propagates the light irradiated from the light irradiation section 18. As shown in FIG. Photodetector 62C detects light propagated by transparent rod 62D. The transparent rod 62D is provided with a plurality of discrete first scattering portions for scattering light. Here, the first scattering portion corresponds to, for example, at least one of scattering portion 166, scattering portion 166A, and scattering portion 166B.

According to such a configuration, by suppressing excessive diffusion of the laser light 18C while it is propagating through the transparent rod 62D, it is possible to suppress a decrease in the light amount of the propagated laser light 18C. As a result, deterioration in photodetection accuracy can be suppressed.

It should be noted that when other configurations exemplified in the present specification are appropriately added to the above configurations, that is, when other configurations in the present specification that are not mentioned as the above configurations are added as appropriate can produce a similar effect.

Also, according to the embodiments described above, the photodetector 62C is located opposite the longitudinal end of the transparent rod 62D. A plurality of scattering portions 166 are discretely arranged along the longitudinal direction of the transparent rod 62D. With such a configuration, light can be effectively propagated along the longitudinal direction of the transparent rod 62D.

Also according to the embodiments described above, the transparent rod 62D has an end facing the photodetector 62C. The width of the second scattering portion, which is one of the plurality of scattering portions 166, is the same as that of the third scattering portion, which is a scattering portion provided closer to the end than the second scattering portion. width or greater. Here, the second scattering portion corresponds to scattering portion 166B, for example. Also, the third scattering portion corresponds to the scattering portion 166A, for example. According to such a configuration, the amount of light scattered by the scattering portion 166B at the position where the propagation distance becomes longer is Since the amount of light scattered by the scattering portion 166A at a position where the propagation distance is short is relatively increased, it is possible to suppress the difference in the amount of light that is detected after propagating through the transparent rod 62D from different incident positions. can. As a result, light detection accuracy can be improved.

Also according to the embodiments described above, the photodetector device comprises a stage 42 . Then, the light irradiation unit 18 irradiates the upper surface of the stage 42 with light. Also, at least a portion of the stage 42 is provided with at least one fourth scattering section for scattering light. Here, the fourth scattering portion corresponds to the scattering portion 142A, for example. Also, the scattering portion 142A is made of a transparent material. Moreover, the transparent rod 62D propagates the light incident through the scattering portion 142A. According to such a configuration, since the scattering portion 142A irradiated with light is made of a transparent material, the light is irradiated even when high-intensity light such as the laser beam 18C is irradiated. It is possible to reduce the damage of the part. Therefore, the positional accuracy of the light detected by the detector 62 is less likely to decrease. In addition, by detecting the scattered light scattered by the scattering section 142A, damage to the detection section 62 due to direct irradiation of light can be prevented even when high-intensity light such as the laser light 18C is detected. can be mitigated.

Further, according to the embodiments described above, each scattering portion 166 is arranged corresponding to the position of the scattering portion 142A. According to such a configuration, the light scattered by the scattering portion 142A and incident on the transparent rod 62D can be further scattered by the scattering portion 142A located directly below the scattering portion 142A. can be propagated to

Also, according to the embodiments described above, the photodetector device comprises a condenser lens 162 and a light blocking plate 164 . Condensing lens 162 condenses the light incident through scattering portion 142A. The light blocking plate 164 is arranged at a position farther from the scattering section 142A than the condenser lens 162 is. Also, the light blocking plate 164 is arranged at the condensing position of the condensing lens 162 . The transparent rod 62D propagates the light condensed by the condensing lens 162. As shown in FIG. According to such a configuration, by detecting the scattered light scattered by the scattering portion 142A with the photodetector 62C while blocking the transmitted light with the light blocking plate 164, when high intensity light such as the laser beam 18C is detected. Even so, it is possible to reduce damage to the detection unit 62 due to direct irradiation of light.

Also, according to the embodiments described above, the plurality of scattering portions 166 are formed by blasting the surface of the transparent rod 62D. According to such a configuration, it is possible to form a scattering portion that is less likely to be damaged by light irradiation and that can suppress outgassing, which is a problem under vacuum (or under reduced pressure).

Also, according to the embodiments described above, the plurality of first scattering portions are the reflective films 168 applied to the lower surfaces of the transparent rods 162D. According to such a configuration, the reflection film 168 discretely provided on the lower surface of the transparent rod 62D increases the reflectance of the lower surface of the transparent rod 62D, thereby suppressing excessive diffusion of the light during propagation and suppressing the light inside the transparent rod 62D. It is possible to improve the propagation efficiency of the light incident on.

Moreover, according to the embodiment described above, the light irradiated from the light irradiation section 18 is the laser light 18C. According to such a configuration, even when high-intensity light such as the laser beam 18C is irradiated, it is possible to suppress a decrease in the amount of light that is propagated by suppressing excessive diffusion during propagation. can.

Also according to the embodiments described above, the photodetector device comprises a chamber in which the transparent rod 62D is enclosed. Here, the chamber corresponds to the vacuum chamber 12, for example. The photodetector 62C detects the light propagated by the transparent rod 62D outside the vacuum chamber 12. FIG. According to such a configuration, since the photodetector 62C of the detection unit 62 is provided outside the vacuum chamber 12, the outgas emitted from the photodetector 62C is prevented from being generated in the vacuum chamber 12. can be done.

<Regarding Modifications of the Embodiments Described Above>
In the embodiments described above, the material, material, size, shape, relative arrangement relationship, implementation conditions, etc. of each component may be described, but these are only examples in all aspects. and shall not be limiting.

Accordingly, myriad variations and equivalents, not exemplified, are envisioned within the scope of the technology disclosed herein. For example, modifications, additions, or omissions of at least one component shall be included.

Further, in the embodiments described above, when a material name is described without being specified, unless there is a contradiction, the material contains other additives, such as an alloy. shall be included.

Reference Signs List 1 light irradiation device 12 vacuum chamber 12A, 12B, 12C opening 14 external fixing part 14B external member 14A, 14C columnar member 16A, 16B bellows 18B, 62E, 162 condenser lens 18 light irradiation part 18A scanner 18C laser beam 20 irradiation window 20A transparent window 21 vacuum pump 22 controller 24 pedestal 42 stage 42A object placement area 42B position calibration area 44 slider 46 base 48 linear guide 50 linear motor mechanism 52 lift pin mechanism 52A lift pin 62 detector 62A light collecting unit 62B fiber 62C photodetector 62D, 162D transparent rod 142 translucent portion 142A, 166, 166A, 166B scattering portion 164 light shielding plate 168 reflecting film

Claims (11)

A photodetector for detecting light emitted from a light emitting unit,
a propagation member for propagating the light irradiated from the light irradiation unit;
a photodetector for detecting the light propagated by the propagation member;
The propagation member is provided with a plurality of discrete first scattering portions for scattering the light.
Photodetector. A photodetector according to claim 1,
The photodetector is positioned opposite a longitudinal end of the propagation member,
the plurality of first scattering parts are discretely arranged along the longitudinal direction of the propagation member;
Photodetector. A photodetector according to claim 1 or 2,
the propagating member has an end facing the photodetector;
The width of the second scattering portion, which is one of the plurality of first scattering portions, is the width of the third scattering portion, which is the scattering portion provided at a position closer to the end than the second scattering portion. is greater than or equal to the width of the scattering part,
Photodetector. A photodetector according to any one of claims 1 to 3,
Equipped with more stages,
The light irradiation unit irradiates the upper surface of the stage with the light,
At least part of the stage is provided with at least one fourth scattering section for scattering the light,
The fourth scattering section is made of a transparent material,
The propagation member propagates the light incident through the fourth scattering section,
Photodetector. A photodetector according to claim 4,
Each of the first scattering parts is arranged corresponding to the position of the fourth scattering part,
Photodetector. A photodetector according to claim 4 or 5,
a condensing lens for condensing the light incident through the fourth scattering section;
a light shielding plate disposed at a position farther from the fourth scattering unit than the condenser lens and at a light condensing position of the condenser lens,
the propagation member propagates the light condensed by the condensing lens;
Photodetector. A photodetector device according to any one of claims 1 to 6,
wherein the plurality of first scattering portions are formed by blasting the surface of the propagation member;
Photodetector. A photodetector device according to any one of claims 1 to 6,
The plurality of first scattering parts are reflective films applied to the lower surface of the propagation member,
Photodetector. A photodetector device according to any one of claims 1 to 8,
The light irradiated from the light irradiation unit is laser light,
Photodetector. A photodetector device according to any one of claims 1 to 9,
further comprising a chamber in which the propagation member is enclosed;
wherein the photodetector detects the light propagated by the propagation member outside the chamber;
Photodetector. at least one light irradiation unit for irradiating light;
a photodetector device according to any one of claims 1 to 10,
Light irradiation device.

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