WO2019235060A1 - Photodetector - Google Patents

Abstract

A photodetector equipped with a substrate which has a surface, a photodetection element which has a first film body positioned on the surface with a gap interposed therebetween, a reference element which has a second film body positioned on the surface with a gap interposed therebetween, a dummy element which has a film body positioned on the surface with a gap interposed therebetween, and a circuit unit which is provided on the substrate and is electrically connected to the photodetection element and the reference element, wherein: the photodetection element detects light on the basis of a change in temperature caused by the receipt of light, and is positioned in a first region of the surface; the reference element compensates for changes in temperature caused by factors other than the receipt of light by the photodetection element, and is positioned in a second region of the surface; the dummy element is positioned on the surface along the outer edge of the first region and/or the outer edge of the second region in a region other than the first and second regions; and the dummy element is electrically insulated from the circuit unit.

Description

Photodetector

This disclosure relates to a photodetector.

Known photodetectors include a light detection element for detecting light based on a temperature change due to light reception, and a reference element for compensating for a temperature change due to factors other than light reception in the light detection element. (For example, refer to Patent Document 1).

JP 2015-45641 A

In the photodetector as described above, in order to ensure detection accuracy as a photodetector, for example, it is conceivable to devise a signal processing method. However, in that case, there is a possibility that the structure of the circuit portion provided on the substrate supporting the light detection element and the reference element, and thus the structure of the light detector may be complicated.

Therefore, an object of the present disclosure is to provide a photodetector that can ensure detection accuracy while suppressing the complexity of the structure.

A photodetector according to one aspect of the present disclosure includes a substrate having a surface, a photodetecting element having a first film body disposed on the surface via a gap, and a second disposed on the surface via the gap. A reference element having a film body, a dummy element having a film body disposed on the surface through a gap, and a circuit portion provided on the substrate and electrically connected to the light detection element and the reference element. The light detection element is an element for detecting light based on a temperature change due to light reception, and is disposed in the first region of the surface. The reference element is a temperature due to a factor other than light reception in the light detection element. An element for compensating for the change, which is disposed in the second region of the surface, and the dummy element is formed in a region other than the first region and the second region of the surface in the outer edge of the first region and the second region. On at least one of the outer edges of the region Are arranged me, dummy elements are circuit electrically insulated.

In this photodetector, when the dummy element is arranged along the outer edge of the first region, for example, at least one is compared with a case where a space is formed without the dummy element. The first film body of the light detection element is placed in a uniform environment, and as a result, the detection accuracy of at least one light detection element is improved. In addition, when the dummy element is arranged along the outer edge of the second region, for example, compared with a case where a space is formed without the dummy element, the first element of the at least one reference element. The two-film body is placed in a uniform environment, and as a result, the detection accuracy of at least one reference element is improved. On the other hand, since the dummy element is electrically insulated from the circuit part, a circuit structure for electrically connecting the dummy element to the circuit part becomes unnecessary. Therefore, according to this photodetector, it is possible to ensure detection accuracy while suppressing the complexity of the structure.

In the photodetector according to one aspect of the present disclosure, the dummy elements are arranged on a surface other than the first region and the second region so as to be arranged in a direction intersecting with at least one of the outer edge of the first region and the outer edge of the second region. A plurality may be arranged in the region. According to this configuration, when the dummy element is arranged along the outer edge of the first region, the first film body of the at least one photodetecting element is placed in a more uniform environment, and as a result, at least The detection accuracy of one photodetecting element is further improved. When the dummy element is arranged along the outer edge of the second region, the second film body of at least one reference element is placed in a more uniform environment, and as a result, the at least one reference element The detection accuracy is further improved.

In the photodetector according to one aspect of the present disclosure, the dummy element is further provided in a region between the first region and the second region on the surface, along at least one of the outer edge of the first region and the outer edge of the second region. It may be arranged. According to this configuration, in addition to the dummy element being disposed along the outer edge of the first region, when the dummy element is disposed in a region between the first region and the second region, The first film body of at least one photodetecting element is placed in a more uniform environment, and as a result, the detection accuracy of the at least one photodetecting element is further improved. Further, in addition to the dummy element being disposed along the outer edge of the second region, when the dummy element is disposed in a region between the first region and the second region, at least one reference The second film body of the element is placed in a more uniform environment, and as a result, the detection accuracy of at least one reference element is further improved.

In the photodetector according to one aspect of the present disclosure, the dummy element is disposed along the outer edge of the second region, and the film body of the dummy element disposed along the outer edge of the second region has a thickness of the substrate. When viewed from the direction, it may have the same shape as the second film body of the reference element. According to this configuration, the second film body of at least one reference element is placed in a more uniform environment, and as a result, the detection accuracy of at least one reference element is further improved.

In the photodetector according to one aspect of the present disclosure, the dummy element is disposed along the outer edge of the first region, and the film body of the dummy element disposed along the outer edge of the first region has a thickness of the substrate. When viewed from the direction, it may have the same shape as the first film body of the light detection element. According to this configuration, the first film body of the at least one photodetecting element is placed in a more uniform environment, and as a result, the detection accuracy of the at least one photodetecting element is further improved.

In the photodetector according to one aspect of the present disclosure, a plurality of dummy elements may be arranged on the surface along the outer edge of the second region so as to surround the second region in at least one row. According to this configuration, the second film body of at least one reference element is placed in a uniform environment, and as a result, the detection accuracy of at least one reference element is improved.

In the photodetector according to one aspect of the present disclosure, a plurality of dummy elements are arranged on the surface along the outer edges of the first region and the second region so as to surround the first region and the second region in at least one row. Also good. According to this configuration, the second film body of at least one reference element and the first film body of at least one photodetecting element are placed in a uniform environment, and as a result, the detection accuracy of at least one reference element, And the detection accuracy of at least one photodetection element improves.

In the photodetector according to one aspect of the present disclosure, the dummy element has a surface along each of the outer edge of the first region and the outer edge of the second region so as to surround each of the first region and the second region in at least one row. A plurality of them may be arranged. According to this configuration, the second film body of at least one reference element and the first film body of at least one photodetecting element are placed in a uniform environment, and as a result, the detection accuracy of at least one reference element, And the detection accuracy of at least one photodetection element improves.

In the photodetector according to one aspect of the present disclosure, the film body of the dummy element disposed along the outer edge of the second region is the same as the second film body of the reference element when viewed from the thickness direction of the substrate. The film body of the dummy element disposed along the outer edge of the first region has the same shape as the first film body of the light detection element when viewed from the thickness direction of the substrate. May be. According to this configuration, the second film body of at least one reference element and the first film body of at least one photodetecting element are placed in a more uniform environment, and as a result, the detection accuracy of at least one reference element , And the detection accuracy of at least one photodetecting element is further improved.

In the photodetector according to one aspect of the present disclosure, the circuit unit may include a signal readout circuit, and the dummy element may overlap with the signal readout circuit when viewed from the thickness direction of the substrate. According to this configuration, it is possible to reduce the size of the photodetector while suppressing the complexity of the structure of the photodetector.

According to the present disclosure, it is possible to provide a photodetector that can ensure detection accuracy while suppressing the complexity of the structure.

FIG. 1 is a plan view of the photodetector according to the first embodiment. FIG. 2 is a diagram showing each region on the surface of the substrate of FIG. FIG. 3 is a plan view of the light detection element, the reference element, the first dummy element, and the second dummy element arranged in each region of FIG. 4 is a perspective view of the photodetecting element of FIG. FIG. 5 is a plan view of the photodetecting element of FIG. 6 is a cross-sectional view of the photodetecting element of FIG. FIG. 7 is a diagram showing the principle of the optical resonance structure. FIG. 8 is a perspective view of the reference element of FIG. FIG. 9 is a plan view of the reference element of FIG. FIG. 10 is a cross-sectional view of the reference element of FIG. FIG. 11 is a perspective view of the first dummy element of FIG. FIG. 12 is a plan view of the first dummy element of FIG. FIG. 13 is a cross-sectional view of the first dummy element of FIG. FIG. 14 is a perspective view of the second dummy element of FIG. FIG. 15 is a plan view of the second dummy element of FIG. FIG. 16 is a cross-sectional view of the second dummy element of FIG. FIG. 17 is a diagram illustrating a method of manufacturing the photodetecting element of FIG. FIG. 18 is a diagram showing a method for manufacturing the photodetecting element of FIG. FIG. 19 is a diagram showing a manufacturing method of the photodetecting element of FIG. FIG. 20 is a diagram showing a manufacturing method of the photodetecting element of FIG. FIG. 21 is a diagram showing a method for manufacturing the photodetecting element of FIG. FIG. 22 is a diagram showing a method for manufacturing the photodetecting element of FIG. FIG. 23 is a diagram showing a method for manufacturing the photodetecting element of FIG. FIG. 24 is a diagram showing a manufacturing method of the photodetecting element of FIG. FIG. 25 is a diagram showing a manufacturing method of the photodetecting element of FIG. FIG. 26 is a diagram showing a method for manufacturing the photodetecting element of FIG. FIG. 27 is a diagram illustrating each region on the surface of the substrate according to the modification of the first embodiment. FIG. 28 is a diagram illustrating each region on the surface of the substrate according to the modified example of the first embodiment. FIG. 29 is a diagram illustrating each region on the surface of the substrate according to the modification of the first embodiment. FIG. 30 is a diagram illustrating each region on the surface of the substrate according to the modified example of the first embodiment. FIG. 31 is a diagram illustrating each region on the surface of the substrate according to the modified example of the first embodiment. FIG. 32 is a diagram illustrating each region on the surface of the substrate according to the modification of the first embodiment. FIG. 33 is a diagram illustrating each region on the surface of the substrate according to the modification of the first embodiment. FIG. 34 is a diagram illustrating each region on the surface of the substrate according to the modification of the first embodiment. FIG. 35 is a diagram illustrating each region on the surface of the substrate according to the modification of the first embodiment. FIG. 36 is a diagram illustrating each region on the surface of the substrate according to the modification of the first embodiment. FIG. 37 is a diagram illustrating each region on the surface of the substrate according to the modification of the first embodiment. FIG. 38 is a plan view of the photodetector of the second embodiment. FIG. 39 is a diagram showing each region on the surface of the substrate of FIG. FIG. 40 is a diagram illustrating each region on the surface of the substrate according to the modification of the second embodiment. FIG. 41 is a diagram illustrating each region on the surface of the substrate according to the modified example of the second embodiment. FIG. 42 is a diagram illustrating each region on the surface of the substrate according to the modification of the second embodiment. FIG. 43 is a diagram illustrating each region on the surface of the substrate according to the modified example of the second embodiment. FIG. 44 is a diagram illustrating each region on the surface of the substrate according to the modified example of the second embodiment.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or equivalent part, and the overlapping description is abbreviate | omitted.

[First Embodiment]
[Configuration of photodetector]
The photodetector 1A shown in FIG. 1 detects light by utilizing a function as a bolometer. The light is, for example, infrared including terahertz waves. When the light is infrared, the photodetector 1A is used for an infrared imager, thermography, or the like. The photodetector 1A has particularly excellent characteristics for detecting light in the wavelength band of 1 μm to several tens of μm. As shown in FIG. 1, the photodetector 1A includes a substrate 2A having a surface 2a, a pixel unit 3, a reference unit 4, a first dummy unit 5, and a second dummy unit 6. . The thickness of the substrate 2A is, for example, about several hundred μm. The pixel unit 3, the reference unit 4, the first dummy unit 5, and the second dummy unit 6 are formed on the surface 2a of the substrate 2A.

When viewed from the Z-axis direction (thickness direction of the substrate 2A), the pixel unit 3 and the reference unit 4 are arranged so as to be aligned in the X-axis direction (direction orthogonal to the Z-axis) parallel to the surface 2a. Yes. The pixel unit 3 and the reference unit 4 are separated from each other. The first dummy part 5 surrounds the pixel part 3. The second dummy part 6 surrounds the reference part 4. The first dummy part 5 and the second dummy part 6 are adjacent to each other.

The circuit board 22A and a plurality of I / O pads 12 are provided on the substrate 2A. The circuit portion 22A is provided in a layered manner on the surface 2a side of the substrate 2A. The I / O pad 12 is composed of a metal film formed on the surface 2a of the substrate 2A. The circuit unit 22A includes the signal readout circuit 7 and a plurality of wirings (not shown) that electrically connect the components to each other. The signal readout circuit 7 includes a correction circuit 8, a lead-out circuit 9, and a plurality of shift registers (scanning circuits) 11a, 11b, and 11c.

The correction circuit 8 is disposed on the side opposite to the pixel unit 3 with respect to the reference unit 4. The lead-out circuit 9 is disposed on the side opposite to the reference unit 4 with respect to the correction circuit 8. The shift register 11a is arranged so as to be aligned with the pixel unit 3 in the Y-axis direction (direction orthogonal to the Z-axis and the X-axis) parallel to the surface 2a. The shift register 11b is arranged so as to be aligned with the reference unit 4 in the Y-axis direction. The shift register 11 c is disposed on the opposite side of the correction circuit 8 with respect to the lead-out circuit 9. The plurality of I / O pads 12 are arranged along the outer edge of the surface 2a.

As shown in FIG. 2, the surface 2a of the substrate 2A includes a first region 3a, a second region 4a, a third region 5a, and a fourth region 6a. The pixel part 3 is arrange | positioned in the 1st area | region 3a among the surfaces 2a. The reference part 4 is arrange | positioned in the 2nd area | region 4a among the surfaces 2a. The first dummy portion 5 is disposed in the third region 5a of the surface 2a. The second dummy portion 6 is disposed in the fourth region 6a of the surface 2a.

The first region 3a and the second region 4a are arranged so as to be aligned in the X-axis direction. The first region 3a and the second region 4a are separated from each other. The first region 3a has, for example, a rectangular shape. The second region 4a has a rectangular shape, for example. The length of the second region 4a in the Y-axis direction is the same as the length of the first region 3a in the Y-axis direction. The length of the second region 4a in the X-axis direction is shorter than the length of the first region 3a in the X-axis direction.

The third region 5a has, for example, a rectangular ring shape. The third region 5a surrounds the first region 3a so as to be adjacent to the first region 3a. The fourth region 6a has, for example, a rectangular ring shape. The fourth region 6a surrounds the second region 4a so as to be adjacent to the second region 4a. The third region 5a and the fourth region 6a are adjacent to each other. The length of the fourth region 6a in the Y-axis direction is the same as the length of the third region 5a in the Y-axis direction. The length of the fourth region 6a in the X-axis direction is shorter than the length of the third region 5a in the X-axis direction. The width of the fourth region 6a surrounding the second region 4a is the same as the width of the third region 5a surrounding the first region 3a.

The outer edge of the pixel unit 3 has, for example, a rectangular shape when viewed from the Z-axis direction. The outer edge of the pixel unit 3 overlaps with the outer edge of the first region 3a when viewed from the Z-axis direction. The outer edge of the reference unit 4 has, for example, a rectangular shape when viewed from the Z-axis direction. The outer edge of the reference portion 4 overlaps with the outer edge of the second region 4a when viewed from the Z-axis direction. The first dummy portion 5 has, for example, a rectangular ring shape when viewed from the Z-axis direction. Each of the outer edge and the inner edge of the first dummy portion 5 overlaps with the outer edge and the inner edge of the third region 5a when viewed from the Z-axis direction. The second dummy portion 6 has, for example, a rectangular ring shape when viewed from the Z-axis direction. Each of the outer edge and the inner edge of the second dummy portion 6 overlaps with the outer edge and the inner edge of the fourth region 6a when viewed from the Z-axis direction.

FIG. 3 is an enlarged view of region III in FIG. As shown in FIG. 3, the pixel unit 3 includes a plurality of light detection elements 30. Each light detection element 30 is an element for detecting light based on a temperature change caused by light reception. The plurality of photodetecting elements 30 are arranged in the first region 3a so as to be arranged in a two-dimensional matrix. The photodetecting elements 30 are arranged to have, for example, about 64 columns × 64 rows to 128 columns × 128 rows. The outer shape of the light detection element 30 when viewed from the Z-axis direction has, for example, a rectangular shape.

The reference unit 4 includes a plurality of reference elements 40. Each reference element 40 is an element for compensating for a temperature change caused by factors other than light reception in the light detection element 30. The plurality of reference elements 40 are arranged in the second region 4a so as to be arranged in a two-dimensional matrix. The reference elements 40 are arranged to have, for example, about 16 columns × 64 rows to 16 columns × 128 rows. The outer shape of the reference element 40 when viewed from the Z-axis direction has, for example, a rectangular shape. In the photodetector 1A, one reference element 40 is used for compensation for a plurality of light detection elements 30 (for example, a plurality of light detection elements 30 arranged in the same row as the one reference element 40).

The first dummy section 5 is composed of a plurality of first dummy elements 50. The plurality of first dummy elements 50 are arranged in the third region 5a so as to surround the pixel unit 3 in a plurality of columns (here, four columns). Thus, a plurality of first dummy elements 50 are arranged on the surface 2a along the outer edge of the first region 3a so as to surround the first region 3a. That is, a plurality of first dummy elements 50 are arranged on the surface 2 a along the outer edge of the pixel unit 3 so as to surround the pixel unit 3. The outer shape of the first dummy element 50 when viewed from the Z-axis direction has, for example, a rectangular shape.

The second dummy section 6 is composed of a plurality of second dummy elements 60. The plurality of second dummy elements 60 are arranged in the fourth region 6a so as to surround the reference unit 4 in a plurality of columns (here, four columns). Thus, a plurality of second dummy elements 60 are arranged on the surface 2a along the outer edge of the second region 4a so as to surround the second region 4a. That is, a plurality of second dummy elements 60 are arranged on the surface 2 a along the outer edge of the reference portion 4 so as to surround the reference portion 4. The outer shape of the second dummy element 60 when viewed from the Z-axis direction has, for example, a rectangular shape.

As described above, the first dummy element 50 is disposed along the outer edge of the first region 3a in the region other than the first region 3a and the second region 4a on the surface 2a of the substrate 2A. Is arranged along the outer edge of the second region 4a. A plurality of first dummy elements 50 are arranged in regions other than the first region 3a and the second region 4a on the surface 2a of the substrate 2A so as to be arranged in a direction intersecting with the outer edge of the first region 3a. A plurality of second dummy elements 60 are arranged in regions other than the first region 3a and the second region 4a on the surface 2a of the substrate 2A so as to be aligned in a direction intersecting with the outer edge of the second region 4a. In the region between the first region 3a and the second region 4a in the surface 2a of the substrate 2A, the first dummy element 50 is disposed along the outer edge of the first region 3a, and the second dummy element 60 is the second dummy element 60. It arrange | positions along the outer edge of the area | region 4a.

[Configuration of photodetection element]
As shown in FIG. 4, the light detection element 30 includes a first film body 31 and a pair of first electrode posts 32 and 33.

The first film body 31 is disposed on the surface 2a of the substrate 2A via the gap S1. The first film body 31 is disposed substantially parallel to the surface 2a of the substrate 2A. The distance between the first film body 31 and the surface 2a of the substrate 2A is, for example, about several μm. As shown in FIGS. 4 and 5, the first film body 31 includes a light receiving portion 34, a pair of first connection portions 35 and 36, and a pair of first beam portions 37 and 38. . The light receiving part 34, the pair of first connection parts 35, 36, and the pair of first beam parts 37, 38 are integrally formed. The first connection portions 35 and 36 are located diagonally to the outer shape of the first film body 31. The first connecting portions 35 and 36 each have, for example, a rectangular shape when viewed from the Z-axis direction. Thus, in the photodetector 1A, the outer shape of the first film body 31 when viewed from the Z-axis direction is such that the light receiving unit 34, the pair of first connection units 35 and 36, and the pair of first beam units 37. , 38 to form a rectangular shape. Note that the outer shape of the first film body 31 when viewed from the Z-axis direction is a light receiving portion 34, a pair of first connection portions 35, 36, a pair of first beam portions 37, 38, and a first described later. This is the outer shape of the entire first film body 31 including the slits 31a and 31b.

The first beam portion 37 is disposed between the light receiving portion 34 and the first connection portion 35. The first beam portion 37 extends along the outer edge of the light receiving portion 34 on one side of the light receiving portion 34. One end of the first beam portion 37 is connected to the first connection portion 35, and the other end of the first beam portion 37 is connected to the light receiving portion 34 at a position near the first connection portion 36. The first slits 31 a are continuously formed between the light receiving part 34 and the first connection part 35 and between the light receiving part 34 and the first beam part 37. The first beam portion 38 is disposed between the light receiving portion 34 and the first connection portion 36. The first beam portion 38 extends along the outer edge of the light receiving portion 34 on the other side of the light receiving portion 34. One end of the first beam portion 38 is connected to the first connection portion 36, and the other end of the first beam portion 38 is connected to the light receiving portion 34 at a position near the first connection portion 35. The first slits 31b are continuously formed between the light receiving part 34 and the first connection part 36, and between the light receiving part 34 and the first beam part 38. The width of each of the first beam portions 37 and 38 is, for example, about several μm. The length of each of the first beam portions 37 and 38 is, for example, about several tens to several hundreds μm. The width of each of the first slits 31a and 31b is, for example, about several μm.

The first electrode post 32 is disposed between the substrate 2A and the first connecting portion 35. The first electrode post 32 has a cylindrical shape that spreads from the substrate 2 </ b> A toward the first film body 31. The first electrode post 33 is disposed between the substrate 2 </ b> A and the first connection portion 36. The first electrode post 33 has a cylindrical shape that spreads from the substrate 2 </ b> A toward the first film body 31. The height of each of the first electrode posts 32 and 33 is, for example, about several μm. Each material of the first electrode posts 32 and 33 is a metal material such as Ti, for example.

FIG. 6 is a cross-sectional view of the light detection element 30. In FIG. 6, II, II-II, III-III, IV-IV, and VV are respectively the II, II-II, III-III, IV-IV, and V lines of FIG. FIG. 6 is a cross-sectional view taken along the line V. As shown in FIG. 6, the first film body 31 includes a pair of first wiring layers 71 and 72, insulating layers 73 and 74, a first resistance layer 75, a light absorption layer 76, and a separation layer 77. , Including.

As shown in FIGS. 5 and 6, when viewed from the Z-axis direction, the first wiring layers 71 and 72 are opposed to each other via the first gap G1 in the light receiving unit. The first gap G1 extends along the first line L1. The first line L1 extends between diagonals facing each other across the center of gravity position C1 of the first film body 31 when viewed from the Z-axis direction. Specifically, when viewed from the Z-axis direction, the first line L1 passes through the center of gravity position C1 of the first film body 31 and extends along the first diagonal line D1 that connects the first connection portions 35 and 36, respectively. It extends in a serpentine shape. The first line L1 has a meandering portion. The meandering part of the light receiving part 34 extends to one side of the light receiving part 34 and then turns back, for example, 180 °, extends to the other side of the light receiving part 34, and then turns back, for example, 180 °, again. It is configured by repeating extending to one side.

In the light detection element 30, when viewed from the Z-axis direction, one side refers to one side (for example, the side on which the first beam portion 37 exists) with respect to the first diagonal line D <b> 1, and the other side Means a side opposite to one side with respect to the first diagonal line D1 when viewed from the Z-axis direction (for example, a side on which the first beam portion 38 exists).

The first wiring layers 71 and 72 are elongated in the direction along the first line L1 in the light receiving unit 34. That is, when viewed from the Z-axis direction, the length of each of the first wiring layers 71 and 72 in the direction along the first line L1 in the light receiving unit 34 is the first in the direction perpendicular to the first line L1. The width of each of the wiring layers 71 and 72 is larger. The direction perpendicular to the first line L1 refers to a direction perpendicular to the tangent at each position of the first line L1 when viewed from the Z-axis direction. When the first line L1 includes a curved portion, the direction perpendicular to the first line L1 is different at each position of the curved portion.

When viewed from the Z-axis direction, the length of each of the first wiring layers 71 and 72 in the direction along the first line L1 in the light receiving unit 34 is, for example, about several tens to several hundreds μm. When viewed from the Z-axis direction, the width of each of the first wiring layers 71 and 72 in the direction perpendicular to the first line L1 is, for example, about several μm. When viewed from the Z-axis direction, the width of the first gap G1 in the direction perpendicular to the first line L1 is, for example, about several μm. The thickness of each of the first wiring layers 71 and 72 is, for example, about several tens to several hundreds nm.

The first wiring layer 71 extends from the light receiving portion 34 to the first connecting portion 35 via the first beam portion 37. The first wiring layer 71 is formed on the first electrode post 32 in the first connection portion 35. The first wiring layer 71 is electrically connected to the first electrode post 32. The first wiring layer 72 extends from the light receiving portion 34 to the first connecting portion 36 via the first beam portion 38. The first wiring layer 72 is formed on the first electrode post 33 in the first connection portion 36. The first wiring layer 72 is electrically connected to the first electrode post 33. Each material of the first wiring layers 71 and 72 is a metal material such as Ti, for example.

The insulating layer 73 is formed on the light receiving portion 34, the first beam portions 37 and 38, and the first connection portions 35 and 36 so as to cover the surface of each of the first wiring layers 71 and 72 on the side opposite to the substrate 2A. It is formed across. The insulating layer 73 is the substrate 2A in the first wiring layers 71 and 72 in a state where the region along the first line L1 is exposed on the surface of each of the first wiring layers 71 and 72 opposite to the substrate 2A. Is formed on the opposite surface. The insulating layer 73 covers the side surfaces of the first wiring layers 71 and 72 in the first connection portions 35 and 36. The insulating layer 74 is formed over the light receiving portion 34, the first beam portions 37 and 38, and the first connection portions 35 and 36 so as to cover the surface of the first wiring layers 71 and 72 on the substrate 2A side. Has been. The insulating layer 74 covers the surface of the first wiring layers 71 and 72 on the substrate 2A side and the outer surfaces 32a and 33a of the first electrode posts 32 and 33 in the first connection portions 35 and 36, respectively. The thickness of each of the insulating layer 73 and the insulating layer 74 is, for example, about several tens of nm. Each material of the insulating layer 73 and the insulating layer 74 is, for example, a silicon nitride film (SiN).

The first resistance layer 75 is formed in the light receiving part 34 so as to cover the insulating layer 73 from the opposite side of the substrate 2A. The first resistance layer 75 is in contact with a region along the first line L1 on the surface of the first wiring layers 71 and 72 opposite to the substrate 2A in the light receiving unit 34. That is, the first resistance layer 75 is electrically connected to each of the first wiring layers 71 and 72 in the light receiving unit 34. The first resistance layer 75 has an electrical resistance that depends on temperature. The thickness of the first resistance layer 75 is, for example, about several tens to several hundreds nm. The material of the first resistance layer 75 is, for example, amorphous silicon (a-Si) that has a large change in electrical resistivity due to a temperature change. As described above, the light receiving unit 34 includes an electrical connection region between each of the pair of first wiring layers 71 and 72 and the first resistance layer 75. The first resistance layer 75 is provided not only in the light receiving part 34 but also in the first connection parts 35 and 36. The first resistance layer 75 is not formed on portions of the first beam portions 37 and 38 except for both end portions thereof. That is, the first resistance layer 75 is divided at the first beam portions 37 and 38.

The light absorption layer 76 faces the surface 2 a of the substrate 2 </ b> A in the light receiving unit 34. The light absorption layer 76 is disposed on the opposite side of the first resistance layer 75 from the substrate 2A. The light absorption layer 76 extends over the entire region of the light receiving unit 34 when viewed from the Z-axis direction. The thickness of the light absorption layer 76 is, for example, about ten and several nanometers. The material of the light absorption layer 76 is, for example, WSi ₂ or Ti.

The separation layer 77 is positioned between the first resistance layer 75 and the light absorption layer 76 in the light receiving unit 34, and the first connection 37, the first beam unit 37, the first beam unit 38, and the first connection. It is formed over the part 35 and the first connection part 36. The thickness of the separation layer 77 is larger than the thickness of each of the first wiring layer 71, the first wiring layer 72, the first resistance layer 75, and the light absorption layer 76. The thickness of the separation layer 77 is, for example, about several hundred nm. The material of the separation layer 77 is, for example, a silicon nitride film (SiN).

In the first film body 31, a through hole 31c is formed. The through hole 31c is a hole through which an etching gas for removing a sacrificial layer 39 described later passes. The through hole 31c has, for example, a circular shape when viewed from the Z-axis direction. The through hole 31c is located, for example, at the center of gravity C1 of the first film body 31 when viewed from the Z-axis direction. The diameter of the through hole 31c is, for example, about several μm.

A light reflecting layer 24 and first electrode pads 25 and 26 are provided on the surface 2a of the substrate 2A. The light reflecting layer 24 faces the light receiving unit 34 in the Z-axis direction (the thickness direction of the semiconductor substrate 21). The light reflection layer 24 faces the light absorption layer 76 in the Z-axis direction, and forms an optical resonance structure together with the light absorption layer 76. The thickness of the light reflection layer 24 is, for example, about several hundred nm. The material of the light reflecting layer 24 is, for example, a metal material such as Al having a high reflectivity with respect to light (for example, infrared rays).

The first electrode pad 25 faces the first connection portion 35 in the Z-axis direction. The first electrode pad 26 faces the first connection part 36 in the Z-axis direction. The light reflection layer 24 and the first electrode pads 25 and 26 form, for example, a rectangular outer shape when viewed from the Z-axis direction. The first electrode pads 25 and 26 are located diagonally to the outer shape. The first electrode pads 25 and 26 have, for example, a rectangular shape when viewed from the Z-axis direction. The first electrode pads 25 and 26 are electrically connected to the circuit unit 22A by wiring. The thickness of each first electrode pad 25, 26 is, for example, about several hundred nm. The material of each first electrode pad 25, 26 is, for example, a metal material such as Al having conductivity.

An insulating layer 27 is formed on the surface 2a of the substrate 2A. The insulating layer 27 covers the outer edge portion of the light reflecting layer 24 so that a part of the surface of the light reflecting layer 24 opposite to the semiconductor substrate 21 is exposed. The thickness of the insulating layer 27 is about several tens to several hundreds nm, for example. The material of the insulating layer 27 is, for example, a silicon nitride film (SiN).

In the insulating layer 27, through holes 27a and 27b facing the first connection portions 35 and 36 are formed. That is, the insulating layer 27 covers the outer edge portions of the first electrode pads 25 and 26 so that part of the surface of each of the first electrode pads 25 and 26 opposite to the semiconductor substrate 21 is exposed.

The first electrode post 32 is joined to the first electrode pad 25 in a state where the protruding portion provided at the end portion on the substrate 2A side enters the through hole 27a. The first electrode post 33 is joined to the first electrode pad 26 in a state where the protruding portion provided at the end portion on the substrate 2A side enters the through hole 27b. Thereby, the photodetection element 30 is electrically connected to the circuit unit 22A. The first film body 31 is supported by the first electrode posts 32 and 33 on the surface 2a of the substrate 2A via the gap S1.

Next, the optical resonant structure will be described in detail. As shown in FIG. 7, a part of incident light A (having a wavelength of λ) incident on the light absorption layer 76 is reflected as reflected light B1 by the light absorption layer 76, and the other part is light absorption layer. 76 is transmitted. The other part of the incident light A that has passed through the light absorption layer 76 is reflected by the light reflection layer 24 as reflected light B2. Then, the reflected light B1 and the reflected light B2 are canceled by interference with each other on the reflection surface of the light absorption layer 76. Thereby, the incident light A is absorbed by the reflection surface of the light absorption layer 76. Heat is generated in the light absorption layer 76 by the energy of the absorbed incident light A.

The absorption rate of the incident light A is determined by the sheet resistance of the light absorption layer 76 and the optical distance t between the light absorption layer 76 and the light reflection layer 24. The thickness of the light absorption layer 76 is set to about 16 nm (when the material of the light absorption layer 76 is WSi ₂ ) so that the sheet resistance becomes a vacuum impedance (377Ω / sq). According to this, the amplitude of the reflected light B <b> 1 reflected by the light absorbing layer 76 matches the amplitude of the reflected light B <b> 2 reflected by the light reflecting layer 24. For this reason, on the reflective surface of the light absorption layer 76, the reflected light B1 and the reflected light B2 efficiently interfere and cancel each other. Therefore, the absorption rate of the incident light A is improved.

The optical distance t is set to be t = (2m−1) λ / 4 (m = 1, 2, 3,...). According to this, the phases of the reflected light B1 and the reflected light B2 are shifted by 180 °. For this reason, on the reflective surface of the light absorption layer 76, the reflected light B1 and the reflected light B2 efficiently interfere and cancel each other. Therefore, the absorption rate of the incident light A is improved. Thus, the light reflection layer 24 forms an optical resonance structure with the light absorption layer 76. When viewed from the Z-axis direction, the larger the area of the overlapping portion of the light reflecting layer 24 and the light absorbing layer 76, the more efficiently the incident light A is absorbed.

[Configuration of reference element]
As shown in FIG. 8, the reference element 40 does not have the light absorption layer 76, and the second slits 41a and 41b are shorter than the first slits 31a and 31b. And is mainly different. The reference element 40 includes a second film body 41 and a pair of second electrode posts 42 and 43.

The second film body 41 is disposed on the surface 2a of the substrate 2A via the gap S2. The second film body 41 is disposed substantially parallel to the surface 2a of the substrate 2A. The distance between the second film body 41 and the surface 2a of the substrate 2A is, for example, about several μm. As shown in FIGS. 8 and 9, the second film body 41 includes a main body 44, a pair of second connection parts 45 and 46, and a pair of second beam parts 47 and 48. . The main body portion 44, the pair of second connection portions 45, 46, and the pair of second beam portions 47, 48 are integrally formed. The second connection parts 45 and 46 are located diagonally to the outer shape of the second film body 41. Each of the second connection portions 45 and 46 has, for example, a rectangular shape when viewed from the Z-axis direction. Thus, in the photodetector 1A, the outer shape of the second film body 41 when viewed from the Z-axis direction is such that the main body portion 44, the pair of second connection portions 45 and 46, and the pair of second beam portions 47. , 48 are formed in a rectangular shape. The outer shape of the second film body 41 when viewed from the Z-axis direction is a main body 44, a pair of second connection portions 45, 46, a pair of second beam portions 47, 48, and a second to be described later. It is the external shape of the 2nd film body 41 whole containing slit 41a, 41b.

The second beam portion 47 is disposed between the main body portion 44 and the second connection portion 45. The second beam portion 47 extends along the outer edge of the main body 44 on one side of the main body 44. One end of the second beam portion 47 is connected to the second connection portion 45, and the other end of the second beam portion 47 is connected to the main body portion 44 at a position in the vicinity of the second connection portion 45. That is, the second beam portion 47 is shorter than the first beam portion 37. A second slit 41 a is continuously formed between the main body 44 and the second connecting portion 45 and between the main body 44 and the second beam portion 47. The second beam portion 48 is disposed between the main body portion 44 and the second connection portion 46. The second beam portion 48 extends along the outer edge of the main body 44 on the other side of the main body 44. One end of the second beam portion 48 is connected to the second connection portion 46, and the other end of the second beam portion 48 is connected to the main body portion 44 at a position near the second connection portion 46. That is, the second beam portion 48 is shorter than the first beam portion 38. The second slits 41 b are continuously formed between the main body 44 and the second connecting portion 46 and between the main body 44 and the second beam portion 48. The width of each of the second beam portions 47 and 48 is, for example, about several μm. The length of each of the second beam portions 47 and 48 is, for example, about several μm to several tens of μm. The width of each of the second slits 41a and 41b is, for example, about several μm.

The second electrode post 42 is disposed between the substrate 2A and the second connection portion 45. The second electrode post 42 has a cylindrical shape that spreads from the substrate 2 </ b> A toward the second film body 41. The second electrode post 43 is disposed between the substrate 2 </ b> A and the second connection portion 46. The second electrode post 43 has a cylindrical shape that spreads from the substrate 2 </ b> A toward the second film body 41. The height of each of the second electrode posts 42 and 43 is, for example, about several μm. Each material of the second electrode posts 42 and 43 is a metal material such as Ti, for example.

FIG. 10 is a cross-sectional view of the reference element 40. In FIG. 10, II, II-II, III-III, IV-IV, and VV are respectively the II, II-II, III-III, IV-IV, and V lines of FIG. FIG. 6 is a cross-sectional view taken along the line V. As shown in FIG. 10, the second film body 41 includes a pair of second wiring layers 81 and 82, insulating layers 83 and 84, a second resistance layer 85, and a separation layer 87.

As shown in FIGS. 9 and 10, when viewed from the Z-axis direction, the second wiring layers 81 and 82 face each other through the second gap G2 in the main body 44. The second gap G2 extends along the second line L2. The second line L2 extends between diagonals facing each other across the center of gravity position C2 of the second film body 41 when viewed from the Z-axis direction. Specifically, when viewed from the Z-axis direction, the second line L2 passes through the center of gravity position C2 of the second film body 41 and extends along the second diagonal line D2 connecting the second connection portions 45 and 46, respectively. It extends in a serpentine shape. The second line L2 has a meandering portion. The meandering portion extends to one side of the main body portion 44 in the main body portion 44, and then, for example, is folded back by 180 °. After extending to the other side of the main body portion 44, for example, it is folded back by 180 °, for example. It is configured by repeating extending to one side.

In the reference element 40, one side means one side (for example, the side where the second beam portion 47 exists) with respect to the second diagonal line D2 when viewed from the Z-axis direction, and the other side means , When viewed from the Z-axis direction, it refers to a side opposite to one side with respect to the second diagonal line D2 (for example, a side where the second beam portion 48 exists).

The second wiring layers 81 and 82 are elongated in the direction along the second line L2 in the main body 44. That is, when viewed from the Z-axis direction, the length of each of the second wiring layers 81 and 82 in the direction along the second line L2 in the main body 44 is the second in the direction perpendicular to the second line L2. It is larger than the width of each of the wiring layers 81 and 82. The direction perpendicular to the second line L2 refers to a direction perpendicular to a tangent at each position of the second line L2 when viewed from the Z-axis direction. When the second line L2 includes a curved portion, the direction perpendicular to the second line L2 is different at each position of the curved portion.

When viewed from the Z-axis direction, the length of each of the second wiring layers 81 and 82 in the direction along the second line L2 in the main body 44 is, for example, about several tens to several hundreds μm. When viewed from the Z-axis direction, the width of each of the second wiring layers 81 and 82 in the direction perpendicular to the second line L2 is, for example, about several μm. When viewed from the Z-axis direction, the width of the second gap G2 in the direction perpendicular to the second line L2 is, for example, about several μm. The thickness of each of the second wiring layers 81 and 82 is, for example, about several tens to several hundreds nm.

The second wiring layer 81 extends from the main body portion 44 to the second connection portion 45 via the second beam portion 47. The second wiring layer 81 is formed on the second electrode post 42 in the second connection portion 45. The second wiring layer 81 is electrically connected to the second electrode post 42. The second wiring layer 82 extends from the main body portion 44 to the second connection portion 46 via the second beam portion 48. The second wiring layer 82 is formed on the second electrode post 43 in the second connection portion 46. The second wiring layer 82 is electrically connected to the second electrode post 43. Each material of the second wiring layers 81 and 82 is a metal material such as Ti, for example.

The insulating layer 83 is formed on the main body 44, the second beam portions 47 and 48, and the second connection portions 45 and 46 so as to cover the surfaces of the second wiring layers 81 and 82 on the side opposite to the substrate 2A. It is formed across. The insulating layer 83 is the substrate 2A in the second wiring layers 81 and 82 in a state where the region along the second line L2 is exposed on the surface of each of the second wiring layers 81 and 82 opposite to the substrate 2A. Is formed on the opposite surface. The insulating layer 83 covers the side surfaces of the second wiring layers 81 and 82 in the second connection portions 45 and 46. The insulating layer 84 is formed over the main body portion 44, the second beam portions 47, 48, and the second connection portions 45, 46 so as to cover the surface of the second wiring layers 81, 82 on the substrate 2A side. Has been. The insulating layer 84 covers the surface of the second wiring layers 81 and 82 on the substrate 2A side and the outer surfaces 42a and 43a of the second electrode posts 42 and 43 in the second connection portions 45 and 46, respectively. Each thickness of the insulating layer 83 and the insulating layer 84 is, for example, about several tens of nm. Each material of the insulating layer 83 and the insulating layer 84 is, for example, a silicon nitride film (SiN).

The second resistance layer 85 is formed in the main body portion 44 so as to cover the insulating layer 83 from the opposite side of the substrate 2A. The second resistance layer 85 is in contact with the region along the second line L <b> 2 on the surface of the main body portion 44 opposite to the substrate 2 </ b> A in each of the second wiring layers 81 and 82. That is, the second resistance layer 85 is electrically connected to each of the second wiring layers 81 and 82 in the main body 44. The second resistance layer 85 has an electrical resistance that depends on temperature. The thickness of the second resistance layer 85 is, for example, about several tens to several hundreds nm. The material of the second resistance layer 85 is, for example, amorphous silicon (a-Si) that has a large change in electrical resistivity due to a temperature change. Thus, the main body 44 includes an electrical connection region between each of the pair of second wiring layers 81 and 82 and the second resistance layer 85. The second resistance layer 85 is provided not only on the main body portion 44 but also on the second connection portions 45 and 46. The second resistance layer 85 is not formed on portions of the second beam portions 47 and 48 except for both end portions thereof. That is, the second resistance layer 85 is divided at the second beam portions 47 and 48.

The separation layer 87 is formed on the main body portion 44, the second beam portions 47 and 48, and the second connection portions 45 and 46 so as to cover the surface of the second resistance layer 85 and the insulating layer 83 on the side opposite to the substrate 2A. It is formed across. The thickness of the separation layer 87 is larger than the thickness of each of the second wiring layer 81, the second wiring layer 82, and the second resistance layer 85. The thickness of the separation layer 87 is, for example, about several hundred nm. The material of the separation layer 87 is, for example, a silicon nitride film (SiN).

In the second film body 41, a through hole 41c is formed. The through hole 41 c is a hole through which an etching gas for removing a sacrificial layer used in the manufacturing process of the reference element 40 passes. The through hole 41c has, for example, a circular shape when viewed from the Z-axis direction. The through hole 41c is located, for example, at the center of gravity C2 of the second film body 41 when viewed from the Z-axis direction. The diameter of the through hole 41c is, for example, about several μm.

The second electrode pads 28 and 29 are further provided on the surface 2a of the substrate 2A. The second electrode pad 28 faces the second connection portion 45 in the Z-axis direction. The second electrode pad 29 faces the second connection portion 46 in the Z-axis direction. The second electrode pads 28 and 29 have, for example, a rectangular shape when viewed from the Z-axis direction. The second electrode pads 28 and 29 are electrically connected to the circuit unit 22A by wiring. The thickness of each second electrode pad 28, 29 is, for example, about several hundred nm. The material of each of the second electrode pads 28 and 29 is, for example, a metal material such as Al having conductivity.

The insulating layer 27 is further formed with through holes 27 c and 27 d that face the second connection portions 45 and 46. That is, the insulating layer 27 covers the outer edge portions of the second electrode pads 28 and 29 so that part of the surface of each of the second electrode pads 28 and 29 opposite to the semiconductor substrate 21 is exposed.

The second electrode post 42 is joined to the second electrode pad 28 in a state where the protruding portion provided at the end portion on the substrate 2A side enters the through hole 27c. The second electrode post 43 is joined to the second electrode pad 29 in a state where the protruding portion provided at the end on the substrate 2A side enters the through hole 27d. Thereby, the reference element 40 is electrically connected to the circuit unit 22A. The second film body 41 is supported on the surface 2a of the substrate 2A by the second electrode posts 42 and 43 via the gap S2.

[Configuration of first dummy element]
As shown in FIGS. 11 and 13, the first dummy element 50 is different from the light detection element 30 in that it does not have the light absorption layer 76 and is electrically insulated from the circuit portion 22A. Mainly different. The first dummy element 50 includes a third film body 51 and a pair of third electrode posts 52 and 53.

The third film body 51 is disposed on the surface 2a of the substrate 2A via the gap S3. The third film body 51 is disposed substantially parallel to the surface 2a of the substrate 2A. The distance between the third film body 51 and the surface 2a of the substrate 2A is, for example, about several μm. As shown in FIGS. 11 and 12, the third film body 51 includes a main body portion 54, a pair of third connection portions 55 and 56, and a pair of third beam portions 57 and 58. . The third film body 51 has the same shape as the first film body 31 when viewed from the Z-axis direction. The main body portion 54, the pair of third connection portions 55, 56, and the pair of third beam portions 57, 58 are integrally formed. The third connection portions 55 and 56 are located on the diagonal of the outer shape of the third film body 51. The third connecting portions 55 and 56 each have, for example, a rectangular shape when viewed from the Z-axis direction. Thus, in the photodetector 1 </ b> A, the outer shape of the third film body 51 when viewed from the Z-axis direction is such that the main body portion 54, the pair of third connection portions 55 and 56, and the pair of third beam portions 57. , 58 to form a rectangular shape. Note that the outer shape of the third film body 51 when viewed from the Z-axis direction is a main body portion 54, a pair of third connection portions 55, 56, a pair of third beam portions 57, 58, and a third to be described later. This is the outer shape of the entire third film body 51 including the slits 51a and 51b.

The third beam portion 57 is disposed between the main body portion 54 and the third connection portion 55. The third beam portion 57 extends along the outer edge of the main body portion 54 on one side of the main body portion 54. One end of the third beam portion 57 is connected to the third connection portion 55, and the other end of the third beam portion 57 is connected to the main body portion 54 at a position near the third connection portion 56. The third slits 51 a are continuously formed between the main body portion 54 and the third connection portion 55 and between the main body portion 54 and the third beam portion 57. The third beam portion 58 is disposed between the main body portion 54 and the third connection portion 56. The third beam portion 58 extends along the outer edge of the main body portion 54 on the other side of the main body portion 54. One end of the third beam portion 58 is connected to the third connection portion 56, and the other end of the third beam portion 58 is connected to the main body portion 54 at a position near the third connection portion 55. The third slits 51b are continuously formed between the main body portion 54 and the third connection portion 56 and between the main body portion 54 and the third beam portion 58. The width of each of the third beam portions 57 and 58 is, for example, about several μm. The length of each of the third beam portions 57 and 58 is, for example, about several tens to several hundreds μm. The width of each of the third slits 51a and 51b is, for example, about several μm.

FIG. 13 is a cross-sectional view of the first dummy element 50. I-I, II-II, III-III, IV-IV, and VV in FIG. 13 are the lines I-I, II-II, III-III, IV-IV, and V-V in FIG. 12, respectively. FIG. 6 is a cross-sectional view taken along the line V. As shown in FIG. 13, the third film body 51 is different from the first film body 31 only in that it does not have the light absorption layer 76, and the other structure is the same as that of the first film body 31. Are the same. Detailed description of the third film body 51 is omitted.

As shown in FIG. 13, in the region facing the first dummy element 50, the surface 2 a of the substrate 2 </ b> A is completely covered with the insulating layer 27. The third electrode posts 52 and 53 are bonded to the surface of the insulating layer 27. Thereby, the first dummy element 50 is electrically insulated from the circuit unit 22A. The third film body 51 is supported by the third electrode posts 52 and 53 on the surface 2a of the substrate 2A via the gap S3.

[Configuration of second dummy element]
As shown in FIGS. 14 and 16, the second dummy element 60 is mainly different from the reference element 40 in that it is electrically insulated from the circuit portion 22A. The second dummy element 60 includes a fourth film body 61 and a pair of fourth electrode posts 62 and 63.

The fourth film body 61 is disposed on the surface 2a of the substrate 2A via the gap S4. The fourth film body 61 is disposed substantially parallel to the surface 2a of the substrate 2A. The distance between the fourth film body 61 and the surface 2a of the substrate 2A is, for example, about several μm. As shown in FIGS. 14 and 15, the fourth film body 61 includes a main body portion 64, a pair of fourth connection portions 65 and 66, and a pair of fourth beam portions 67 and 68. . The fourth film body 61 has the same shape as the second film body 41 when viewed from the Z-axis direction. The main body portion 64, the pair of fourth connection portions 65, 66, and the pair of fourth beam portions 67, 68 are integrally formed. The fourth connection portions 65 and 66 are located on the diagonal of the outer shape of the fourth film body 61. The fourth connecting portions 65 and 66 each have, for example, a rectangular shape when viewed from the Z-axis direction. Thus, in the photodetector 1 </ b> A, the outer shape of the fourth film body 61 when viewed from the Z-axis direction is the main body portion 64, the pair of fourth connection portions 65 and 66, and the pair of fourth beam portions 67. , 68 to form a rectangular shape. Note that the outer shape of the fourth film body 61 when viewed from the Z-axis direction is a main body portion 64, a pair of fourth connection portions 65, 66, a pair of fourth beam portions 67, 68, and a fourth to be described later. This is the overall shape of the fourth film body 61 including the slits 61a and 61b.

The fourth beam portion 67 is disposed between the main body portion 64 and the fourth connection portion 65. The fourth beam portion 67 extends along the outer edge of the main body portion 64 on one side of the main body portion 64. One end of the fourth beam portion 67 is connected to the fourth connection portion 65, and the other end of the fourth beam portion 67 is connected to the main body portion 64 at a position near the fourth connection portion 65. That is, the fourth beam portion 67 is shorter than the first beam portion 37 and the third beam portion 57. A fourth slit 61 a is continuously formed between the main body portion 64 and the fourth connection portion 65 and between the main body portion 64 and the fourth beam portion 67. The fourth beam portion 68 is disposed between the main body portion 64 and the fourth connection portion 66. The fourth beam portion 68 extends along the outer edge of the main body portion 64 on the other side of the main body portion 64. One end of the fourth beam portion 68 is connected to the fourth connection portion 66, and the other end of the fourth beam portion 68 is connected to the main body portion 64 at a position near the fourth connection portion 66. That is, the fourth beam portion 68 is shorter than the first beam portion 38 and the third beam portion 58. The fourth slits 61 b are continuously formed between the main body portion 64 and the fourth connection portion 66 and between the main body portion 64 and the fourth beam portion 68. The width of each of the fourth beam portions 67 and 68 is, for example, about several μm. The length of each of the fourth beam portions 67 and 68 is, for example, about several μm to several tens of μm. The width of each of the fourth slits 61a and 61b is, for example, about several μm.

FIG. 16 is a cross-sectional view of the second dummy element 60. I-I, II-II, III-III, IV-IV, and VV in FIG. 16 are respectively the II, II-II, III-III, IV-IV, and V-V lines of FIG. FIG. 6 is a cross-sectional view taken along the line V. As shown in FIG. 16, the structure of the fourth film body 61 is the same as that of the second film body 41. Detailed description of the fourth film body 61 is omitted.

As shown in FIG. 16, the surface 2 a of the substrate 2 </ b> A is completely covered with the insulating layer 27 in the region facing the second dummy element 60. The fourth electrode posts 62 and 63 are bonded to the surface of the insulating layer 27. Thereby, the second dummy element 60 is electrically insulated from the circuit portion 22A. The fourth film body 61 is supported by the fourth electrode posts 62 and 63 on the surface 2a of the substrate 2A via the gap S4.

[Substrate structure]
As shown in FIGS. 6, 10, 13, and 16, the substrate 2 </ b> A includes a semiconductor substrate 21, a circuit unit 22 </ b> A, and an insulating layer 23. The material of the semiconductor substrate 21 is, for example, silicon. The circuit portion 22 </ b> A is provided in a layered manner on the surface of the semiconductor substrate 21. The insulating layer 23 is formed on the semiconductor substrate 21 so that the surface 2a of the substrate 2A becomes flat (ie, the correction circuit 8, the lead-out circuit 9, and the shift registers 11a, 11b, and 11c) And a plurality of wirings that electrically connect the components to each other). The material of the insulating layer 23 is, for example, a silicon nitride film (SiN).

Some of the first dummy elements 50 and some of the second dummy elements 60 overlap the circuit portion 22A when viewed from the Z-axis direction. Specifically, some of the first dummy elements 50 and some of the second dummy elements 60 overlap with the signal readout circuit 7 when viewed from the Z-axis direction (see FIG. 1). More specifically, when viewed from the Z-axis direction, the first dummy element 50 disposed on the shift register 11a side with respect to the pixel unit 3 overlaps the shift register 11a. When viewed from the Z-axis direction, the second dummy element 60 disposed on the shift register 11b side with respect to the reference unit 4 overlaps the shift register 11b. When viewed from the Z-axis direction, the second dummy element 60 disposed on the correction circuit 8 side with respect to the reference unit 4 overlaps the correction circuit 8. The second dummy element 60 disposed on the correction circuit 8 side with respect to the reference unit 4 may overlap with the lead-out circuit 9. Note that, when viewed from the Z-axis direction, the dummy elements overlap with the signal readout circuit 7 that at least some of the dummy elements overlap with the signal readout circuit 7. Say.

[Operation of photodetector]
In the photodetector 1A configured as described above, light is detected as follows. First, when light enters the light receiving portion 34 of the light detection element 30, heat is generated in the light absorption layer 76 that constitutes the optical resonance structure described above. At this time, the light receiving unit 34 and the substrate 2A are thermally separated by the gap S1. In addition, the light receiving part 34, the first connection part 35, and the first beam part 37 are thermally separated by the first slit 31a. In addition, the light receiving part 34, the first connection part 36, and the first beam part 38 are thermally separated by the first slit 31b. For this reason, it is suppressed that the heat generated in the light absorption layer 76 escapes to the substrate 2A side via the first beam portions 37 and 38 and the first connection portions 35 and 36. Further, the light absorption layer 76 and the first wiring layers 71 and 72 are thermally separated by the separation layer 77. For this reason, before the heat generated in the light absorption layer 76 is sufficiently transmitted to the first resistance layer 75 via the separation layer 77, the heat escapes to the substrate 2A side via the first wiring layers 71 and 72. It is suppressed.

The heat generated in the light absorption layer 76 is transmitted to the first resistance layer 75 through the separation layer 77. As a result of this heat, the temperature of the first resistance layer 75 increases and the electrical resistance decreases. A signal due to the change in electrical resistance is sent to the signal readout circuit 7 via the first wiring layers 71 and 72, the first electrode posts 32 and 33, and the first electrode pads 25 and 26. When a drive signal is input via the I / O pad 12, the shift register 11 a and the shift register 11 c specify the column and row addresses in the pixel unit 3 and select the signals in the respective light detection elements 30. Read out. At this time, a signal due to a change in electrical resistance is also sent from the reference element 40 of the reference unit 4 to the signal readout circuit 7. When a drive signal is input via the I / O pad 12, the shift register 11 b and the shift register 11 c specify the column and row addresses in the reference unit 4 and select the signals in each reference element 40. read out. The correction circuit 8 corrects and outputs the signals read by the shift registers 11a, 11b, and 11c. The lead-out circuit 9 amplifies, measures and holds the signal output by the correction circuit 8. The I / O pad 12 sequentially outputs signals amplified, measured and held by the lead-out circuit 9. In the photodetector 1 </ b> A, light is detected based on the difference between the signal from the light detection element 30 and the signal from the reference element 40.

A signal in one reference element 40 is read each time a signal in each of a plurality of corresponding light detection elements 30 is read. That is, one reference element 40 is used for compensation of a plurality of corresponding light detection elements 30. For this reason, the detection accuracy of one reference element 40 affects the detection accuracy of a plurality of light detection elements 30. In addition, the number of times the signal is read from the reference element 40 is larger than the number of times the signal is read from the photodetecting element 30. For this reason, the reference element 40 is easily deteriorated as compared with the photodetecting element 30. For this reason, a device for ensuring the compensation accuracy by the reference element is indispensable.

[Action and effect]
As described above, in the photodetector 1A, the first dummy element 50 is disposed along the outer edge of the first region 3a, and the second dummy element 60 is disposed along the outer edge of the second region 4a. Therefore, the first film body 31 of the photodetecting element 30 and the second film of the reference element 40 are compared with the case where a space is formed without the first dummy element 50 and the second dummy element 60. The body 41 is placed in a uniform environment. As a result, the detection accuracy of the light detection element 30 and the detection accuracy of the reference element 40 are improved. On the other hand, since the first dummy element 50 and the second dummy element 60 are electrically insulated from the circuit part 22A, the first dummy element 50 and the second dummy element 60 are electrically connected to the circuit part 22A. This eliminates the need for a circuit structure. Therefore, according to the photodetector 1A, detection accuracy can be ensured while suppressing the complexity of the structure.

In the photodetector 1A, a plurality of first dummy elements 50 are arranged in a region other than the first region 3a and the second region 4a on the surface 2a so as to be arranged in a direction intersecting with the outer edge of the first region 3a. A plurality of second dummy elements 60 are arranged in regions other than the first region 3a and the second region 4a on the surface 2a so as to be arranged in a direction intersecting with the outer edge of the second region 4a. According to this configuration, the first film body 31 of the light detection element 30 and the second film body 41 of the reference element 40 are placed in a more uniform environment. As a result, the detection accuracy of the light detection element 30 and the reference The detection accuracy of the element 40 is further improved.

In the photodetector 1A, the first dummy element 50 is disposed in the region between the first region 3a and the second region 4a on the surface 2a along the outer edge of the first region 3a, and the second dummy element 50A. The element 60 is arranged along the outer edge of the second region 4a in the region between the first region 3a and the second region 4a on the surface 2a. According to this configuration, in addition to the first dummy element 50 being disposed along the outer edge of the first region 3a, the first dummy element 50 is a region between the first region 3a and the second region 4a. In addition to the second dummy element 60 being disposed along the outer edge of the second region 4a, the second dummy element 60 is disposed in a region between the first region 3a and the second region 4a. Has been. Therefore, the first film body 31 of the light detection element 30 and the second film body 41 of the reference element 40 are placed in a more uniform environment. As a result, the detection accuracy of the light detection element 30 and the detection of the reference element 40 The accuracy is further improved.

In the photodetector 1A, the first dummy element 50 and the second dummy element 60 each surround the first region 3a and the second region 4a in four rows so as to surround the first region 3a and the second region 4a. A plurality of surfaces 2a are arranged along the outer edges of the two regions 4a. According to this configuration, the second film body 41 of the reference element 40 and the first film body 31 of the light detection element 30 are placed in a uniform environment. As a result, the detection accuracy of the reference element 40 and the light detection element 30 detection accuracy is improved.

In the photodetector 1A, the fourth film body 61 of the second dummy element 60 disposed along the outer edge of the second region 4a is the second film body of the reference element 40 when viewed from the Z-axis direction. 41. The third film body 51 of the first dummy element 50 disposed along the outer edge of the first region 3a has the same shape as that of the first region 3a. It has the same shape as the single film body 31. According to this configuration, the second film body 41 of the reference element 40 and the first film body 31 of the light detection element 30 are placed in a more uniform environment. As a result, the detection accuracy of the reference element 40 and the light detection The detection accuracy of the element 30 is further improved.

Further, in the photodetector 1A, the circuit unit 22A includes the signal readout circuit 7, and signal readout is performed when some of the first dummy elements 50 and some of the second dummy elements 60 are viewed from the Z-axis direction. It overlaps with the circuit 7. According to this configuration, it is possible to reduce the size of the photodetector 1A while suppressing the complexity of the structure of the photodetector 1A. Further, by shortening the wiring length of the signal read circuit 7, the read characteristics of the signal read circuit 7 can be improved.

In the photodetector 1A, a plurality of first dummy elements 50 are arranged on the surface 2a along the outer edge of the first region 3a so as to surround the first region 3a. Therefore, stray light that enters the first film body 31 from the side of the light detection element 30 is blocked by the first dummy element 50. Thereby, the detection accuracy of the photodetecting element 30 is improved.

[Method for Manufacturing Photodetection Element]
Next, a method for manufacturing the photodetecting element 30 will be described with reference to FIGS. In FIGS. 17 to 23 and FIG. 26, II, II-II, III-III, IV-IV, and VV in (b) are respectively taken along line II in (a), It is sectional drawing along the II-II line, the III-III line, the IV-IV line, and the VV line. In FIG. 24 and FIG. 25, the figure as in the above (a) is omitted.

First, as shown in FIG. 17, a substrate 2A provided with a light reflecting layer 24, first electrode pads 25 and 26, and an insulating layer 27 is prepared. Subsequently, as shown in FIG. 18, a sacrificial layer 39 is formed on the surface 2a of the substrate 2A so as to cover the light reflecting layer 24, the first electrode pads 25 and 26, and the insulating layer 27. The material of the sacrificial layer 39 is, for example, polyimide. Subsequently, as shown in FIG. 19, through holes 39 a and 39 b are formed in the sacrificial layer 39 by removing a part of the sacrificial layer 39 by etching. The through holes 39a and 39b are formed on the first electrode pads 25 and 26, respectively, corresponding to the through holes 27a and 27b. In the through holes 39a and 39b, the surfaces of the first electrode pads 25 and 26 opposite to the substrate 2A are exposed. The inner surface of each through- hole 39a, 39b is, for example, a truncated cone-shaped tapered surface. The inner surfaces of the through holes 39a and 39b extend from the first electrode pads 25 and 26 toward the opposite side of the substrate 2A, respectively. The small diameters of the through holes 39a and 39b are larger than the diameters of the through holes 27a and 27b.

Subsequently, as shown in FIG. 20, an insulating layer 74 is formed on the sacrificial layer 39. The insulating layer 74 is formed so that the inner surface of each of the through holes 39a and 39b is a truncated cone-shaped tapered surface, for example. Subsequently, a part of the insulating layer 74 is removed by etching, so that the surface of each of the first electrode pads 25 and 26 opposite to the substrate 2A is exposed.

Subsequently, as shown in FIG. 21, the first electrode post 32 is formed on the insulating layer 74 in the through hole 39a, and the first electrode post 33 is formed on the insulating layer 74 in the through hole 39b. Each of the first electrode posts 32 and 33 is formed by vapor deposition, for example. The first electrode posts 32 and 33 are processed into a predetermined shape by dry etching, for example. Subsequently, as shown in FIG. 22, first wiring layers 71 and 72 are formed on the insulating layer 74 so as to cover the first electrode posts 32 and 33. Each of the first wiring layers 71 and 72 is formed by vapor deposition, for example. And the 1st wiring layers 71 and 72 are processed into the shape mentioned above by dry etching, for example.

Subsequently, as shown in FIG. 23, the light receiving unit 34, the first beam units 37 and 38, and the first connection units 35 and 36 so as to cover the first wiring layers 71 and 72 from the opposite side of the substrate 2 </ b> A. Then, an insulating layer 73 is formed. The insulating layer 73 is processed into the shape described above by etching. Next, as shown in FIG. 24, in the light receiving part 34, the first resistance layer 75 is formed so as to cover the insulating layer 73 from the opposite side of the substrate 2 </ b> A, and in the first connection parts 35 and 36, the insulating layer A first resistance layer 75 is formed on 73. The first resistance layer 75 is processed into the shape described above, for example, by dry etching. Then, in the light receiving portion 34 and the first connection portions 35 and 36, a separation layer 77 is formed so as to cover the first resistance layer 75 from the opposite side of the substrate 2A, and in the first beam portion 37 and the first beam portion 38, A separation layer 77 is formed on the insulating layer 73.

Subsequently, as shown in FIG. 25, in the light receiving part 34, the light absorption layer 76 is formed on the separation layer 77, and the through hole 31c is further formed. The light absorption layer 76 is processed into the shape described above by etching. The through hole 31c is formed at the position described above by etching. Subsequently, as shown in FIG. 26, the first slits 31a and 31b are formed at the above-described positions by, for example, dry etching, and further, dry etching is advanced from the first slits 31a and 31b and the through holes 31c, thereby sacrificing layers. By removing 39, the void S1 is formed.

The method for manufacturing the reference element 40 is different from the method for manufacturing the photodetecting element 30 described above in that the light absorption layer 76 is not formed. Further, in the manufacturing method of the first dummy element 50 and the second dummy element 60, the light absorption layer 76 is not formed, and the sacrificial layer 39 and a part of the insulating layer 84 are removed to be exposed. This is different from the method for manufacturing the photodetecting element 30 described above in that it is not the surface of the electrode pad but the surface of the insulating layer 27. It should be noted that the plurality of photodetecting elements 30, the plurality of reference elements 40, the plurality of first dummy elements 50, and the plurality of second dummy elements 60 are manufactured by the light reflecting layer 24, the first electrode pads 25 and 26, and the insulation. It is carried out simultaneously with the substrate 2A provided with the layer 27.

In the manufacturing method of the photodetecting element 30, when dry etching is performed, for example, near the center of the first region 3a and the edge of the first region 3a, an etchant (etching gas) is generated due to a loading effect or the like. The density distribution may be biased, and the shapes of the first electrode posts 32 and 33, the first wiring layers 71 and 72, the first resistance layer 75, and the first film body 31 may be uneven. As a result, there is a possibility that the detection accuracy by the manufactured light detection element 30 may be lowered. Therefore, since the light detection element 30 is manufactured simultaneously with the plurality of first dummy elements 50 surrounding the first region 3a as described above, the vicinity of the center of the first region 3a and the first region 3a are manufactured. The unevenness of the etching pattern is prevented from becoming non-uniform at the edge. As a result, unevenness in the etchant density distribution is suppressed from occurring near the center of the first region 3a and the edge of the first region 3a due to the loading effect. Therefore, the first electrode posts 32 and 33, the first wiring layers 71 and 72, the first resistance layer 75, and the first film body 31 are prevented from being unevenly shaped. That is, the manufacturing process of the light detection element 30 is stabilized. Therefore, the detection accuracy by the light detection element 30 is ensured.

Such an effect is similarly achieved in the manufacture of the reference element 40. That is, since the reference element 40 is manufactured simultaneously with the plurality of second dummy elements 60 surrounding the second region 4a as described above, the reference element 40 is formed near the center of the second region 4a and the second region 4a. It is possible to prevent the etching pattern from becoming nonuniform at the edge. As a result, it is possible to suppress an uneven distribution of the etchant density distribution near the center of the second region 4a and the edge of the second region 4a due to the loading effect. Therefore, the second electrode posts 42 and 43, the second wiring layers 81 and 82, the second resistance layer 85, and the second film body 41 are prevented from being non-uniform in shape. That is, the manufacturing process of the reference element 40 is stabilized. Therefore, the detection accuracy by the reference element 40 is ensured.

Further, since the second film body 41 does not have the light absorption layer 76, it may be formed thinner than the first film body 31. For this reason, the second film body 41 is more easily deformed than the first film body 31. Therefore, it is important to manufacture the second film body 41 with high accuracy. That is, the effect of stabilizing the manufacturing process as described above is particularly effective for the reference element 40. Further, the second dummy element 60 has the same shape as the reference element 40 and the first dummy element 50 has the same shape as the light detection element 30 when viewed from the Z-axis direction. The effect of suppressing the non-uniformity of the density state of the etched pattern is further remarkable.

[Modification of First Embodiment]
The first embodiment of the present disclosure has been described above, but the present disclosure is not limited to the first embodiment.

In the example, each of the third region 5a and the fourth region 6a surrounds each of the first region 3a and the second region 4a. However, as illustrated in FIG. 27, only the fourth region 6a has the second region 6a. Each of the first region 3a and the second region 4a may be enclosed. That is, only the second dummy element 60 surrounds each of the first region 3a and the second region 4a on the surface 2a of the substrate 2A along the outer edge of the first region 3a and the outer edge of the second region 4a. A plurality of them may be arranged.

As shown in FIG. 28, the third region 5a and the fourth region 6a may surround the entire outer edges of the first region 3a and the second region 4a. That is, the first dummy element 50 and the second dummy element 60 surround the entire outer edges of the first area 3a and the second area 4a along the outer edges of the first area 3a and the second area 4a. A plurality of surfaces may be arranged on the surface 2a. Specifically, the third region 5a has a U shape that opens toward the second region 4a, and the fourth region 6a has a U shape that opens toward the first region 3a. ing. The third region 5a and the fourth region 6a are adjacent to each other so as to form a rectangular ring shape. The first region 3a and the second region 4a are located inside the rectangular ring. In this case, the first region 3a and the second region 4a are adjacent to each other. The first region 3a and the second region 4a may be separated from each other. The first dummy element 50 and the second dummy element 60 are not disposed between the first region 3a and the second region 4a.

Even when the third region 5a and the fourth region 6a surround the entire outer edges of the first region 3a and the second region 4a, the second film body 41 of the reference element 40 and the first detection element 30 The film body 31 is placed in a uniform environment. As a result, the detection accuracy of the reference element 40 and the detection accuracy of the light detection element 30 are improved. The entire outer edge of the first region 3a and the second region 4a refers to the outer edge of the region extending from the first region 3a to the second region 4a. When the first region 3a and the second region 4a are adjacent to each other, the region constituted by the first region 3a and the second region 4a is a region extending from the first region 3a to the second region 4a. is there. When the first region 3a and the second region 4a are separated from each other, the total of the first region 3a, the second region 4a, and the region between the first region 3a and the second region 4a is This is an area extending from the first area 3a to the second area 4a.

Further, as shown in FIG. 29, only the fourth region 6a may surround the entire outer edges of the first region 3a and the second region 4a. That is, only the second dummy element 60 is disposed on the surface 2a of the substrate 2A along the outer edges of the first region 3a and the second region 4a so as to surround the entire outer edges of the first region 3a and the second region 4a. May be.

Further, as shown in FIG. 30, the first region 3a may not be surrounded by any region. That is, the first region 3a may not be surrounded by any dummy element. The fourth area 6a surrounds only the second area 4a. That is, a plurality of second dummy elements 60 are arranged on the surface 2a of the substrate 2A along the outer edge of the second region 4a so as to surround only the second region 4a.

Further, as shown in FIG. 31, the fourth region 6a may surround only the side portion of the second region 4a other than the side portion on the first region 3a side. That is, a plurality of second dummy elements 60 are arranged on the surface 2a of the substrate 2A along the outer edge of the second region 4a so as to surround only the side portion of the second region 4a other than the side portion on the first region 3a side. It may be. In this case, the first region 3a and the second region 4a are adjacent to each other. The first region 3a and the second region 4a may be separated from each other.

Further, as shown in FIG. 32, the fourth region 6a may be formed only on the opposite side of the second region 4a from the first region 3a. That is, the second dummy element 60 may be disposed along the outer edge of the second region 4a only in the region opposite to the first region 3a with respect to the second region 4a. In this case, the first region 3a and the second region 4a are adjacent to each other. The first region 3a and the second region 4a may be separated from each other.

As shown in FIG. 33, the fourth region 6a is formed only on the opposite side of the second region 4a from the first region 3a, and the third region 5a is formed with respect to the first region 3a. Thus, it may be formed only on the side opposite to the second region 4a. That is, the second dummy element 60 is arranged along the outer edge of the second region 4a only in the region opposite to the first region 3a with respect to the second region 4a. You may arrange | position along the outer edge of 1st area | region 3a only to the area | region on the opposite side to 2nd area | region 4a with respect to area | region 3a. In this case, the first region 3a and the second region 4a are adjacent to each other. The first region 3a and the second region 4a may be separated from each other.

Further, as shown in FIG. 34, the third region 5a may include a plurality of rectangular regions along each side of the first region 3a. The length of the third region 5a along the side of the first region 3a is the same as the length of the side of the first region 3a. Similarly, the fourth region 6a may include a plurality of regions along each side of the second region 4a. The length of the region of the fourth region 6a along the side of the second region 4a is the same as the length of the side of the second region 4a.

As shown in FIG. 35, even when the first region 3a is not surrounded by any region, the fourth region 6a includes a plurality of regions along each side of the second region 4a. You may go out.

As shown in FIG. 36, even when the third region 5a and the fourth region 6a surround the entire outer edges of the first region 3a and the second region 4a, the third region 5a The 4th area | region 6a may contain the some area | region along each side part of the 2nd area | region 4a including the some rectangular area | region along each edge part of the area | region 3a. In this case, the first region 3a and the second region 4a are adjacent to each other. The first region 3a and the second region 4a may be separated from each other.

In addition, as shown in FIG. 37, even when the fourth region 6a surrounds only the side other than the side of the second region 4a on the first region 3a side, the fourth region 6a is the second region. A plurality of regions along each side of 4a may be included. In this case, the first region 3a and the second region 4a are adjacent to each other. The first region 3a and the second region 4a may be separated from each other.

Although the example in which the first dummy element 50 surrounds the first region 3a in four columns and the second dummy element 60 surrounds the second region 4a in four columns has been shown, the first dummy element 50 includes at least the first region 3a. The second dummy elements 60 need only surround the second region 4a in at least one column. Even when the first dummy element 50 and the second dummy element 60 surround the entire outer edges of the first region 3a and the second region 4a, the first dummy element 50 and the second dummy element 60 are at least It is only necessary to surround the entire outer edges of the first region 3a and the second region 4a in one row.

In addition, although the example in which the light detection elements 30 are arranged to have, for example, about 64 columns × 64 rows to 128 columns × 128 rows has been shown, the light detection elements 30 have, for example, 32 columns × 32 rows to 480 columns × It only needs to be arranged so as to have about 640 rows. Further, the example in which the reference elements 40 are arranged so as to have, for example, about 16 columns × 64 rows to 16 columns × 128 rows is shown. However, the reference elements 40 are, for example, 1 column × 32 rows to 24 columns × 640 rows. It suffices if they are arranged so as to be approximately.

The first dummy element 50 is disposed along the outer edge of the first region 3a in the region between the first region 3a and the second region 4a in the surface 2a of the substrate 2A, and the second dummy element 60 is Although an example in which the two regions 4a are arranged along the outer edge is shown, the first dummy element 50 is first in the region between the first region 3a and the second region 4a on the surface 2a of the substrate 2A. The second dummy element 60 may be disposed along the outer edge of the second region 4a. Alternatively, the second dummy element 60 may be disposed along the outer edge of the second region 4a. That is, at least one of the first dummy element 50 and the second dummy element 60 in the region between the first region 3a and the second region 4a on the surface 2a of the substrate 2A includes the outer edge of the first region 3a and the second region 4a. What is necessary is just to arrange | position along at least one of the outer edges of 2 area | region 4a.

Also, the types of the dummy elements arranged along the outer edge of the first region 3a and the dummy elements arranged along the outer edge of the second region 4a are not limited. For example, the second dummy element 60 may be disposed along the outer edge of the first region 3a, and the first dummy element 50 may be disposed along the outer edge of the second region 4a. The first dummy element 50 and the second dummy element 60 are arranged along the outer edge of the first region 3a, and the first dummy element 50 and the second dummy element 60 are arranged along the outer edge of the second region 4a. May be. Further, a dummy element other than the first dummy element 50 and the second dummy element 60 may be arranged instead of the first dummy element 50 or the second dummy element 60.

Moreover, although the example in which the 1st area | region 3a and the 2nd area | region 4a are exhibiting the rectangular shape was shown, the 1st area | region 3a and the 2nd area | region 4a are exhibiting polygonal shapes or circular shapes other than rectangular shape, for example. Also good. That is, the pixel unit 3 and the reference unit 4 may have, for example, a polygonal shape or a circular shape other than a rectangular shape when viewed from the Z-axis direction. Moreover, although the 3rd area | region 5a and the 4th area | region 6a showed the example which is exhibiting the rectangular ring shape, the outer edge of the 3rd area | region 5a and the 4th area | region 6a exhibits polygonal shapes other than rectangular shape, or circular shape, for example. It may be. That is, the outer edges of the first dummy portion 5 and the second dummy portion 6 may have, for example, a polygonal shape or a circular shape other than a rectangular shape when viewed from the Z-axis direction.

Moreover, although each of the 1st film body 31, the 2nd film body 41, the 3rd film body 51, and the 4th film body 61 showed from the Z-axis direction, the example which is exhibiting the rectangular shape was shown. Each of the first film body 31, the second film body 41, the third film body 51, and the fourth film body 61 has, for example, a polygonal shape other than a rectangular shape when viewed from the Z-axis direction. Also good.

In addition, an example in which some of the first dummy elements 50 and some of the second dummy elements 60 overlap with the signal readout circuit 7 when viewed from the Z-axis direction is shown. 50 and the second dummy element 60 may not overlap with the signal readout circuit 7 when viewed from the Z-axis direction.

In addition, at least one of the first dummy element 50 and the second dummy element 60 has only one of the outer edge of the first region 3a and the outer edge of the second region 4a in a region other than the first region 3a and the second region 4a. It may be arranged along. That is, at least one of the first dummy element 50 and the second dummy element 60 extends along the at least one of the outer edge of the first region 3a and the outer edge of the second region 4a in a region other than the first region 3a and the second region 4a. As long as they are arranged.

A plurality of first dummy elements 50 are arranged in regions other than the first region 3a and the second region 4a on the surface 2a of the substrate 2A so as to be arranged in a direction intersecting with the outer edge of the first region 3a. Although the dummy element 60 has been shown in an example in which a plurality of dummy elements 60 are arranged in regions other than the first region 3a and the second region 4a on the surface 2a of the substrate 2A so as to line up in the direction intersecting the outer edge of the second region 4a. However, the present invention is not limited to this. Of the surface 2a of the substrate 2A, at least one of the first dummy element 50 and the second dummy element 60 is arranged in a direction intersecting only one of the outer edge of the first region 3a and the outer edge of the second region 4a. A plurality of areas may be arranged in areas other than the first area 3a and the second area 4a. That is, of the surface 2a of the substrate 2A, at least one of the first dummy element 50 and the second dummy element 60 is arranged in a direction intersecting at least one of the outer edge of the first region 3a and the outer edge of the second region 4a. It suffices if a plurality of areas are arranged in areas other than the first area 3a and the second area 4a.

Moreover, although the example in which the first dummy element 50 does not have the light absorption layer 76 has been shown, the first dummy element 50 may have the light absorption layer 76. Similarly, in the manufacturing method of the first dummy element 50, the example in which the light absorption layer 76 is not formed is shown. However, in the manufacturing method of the first dummy element 50, the light absorption layer 76 may be formed. In this case, the manufacturing process of the light detection element 30 (light absorption layer 76) is stabilized.

[Second Embodiment]
As shown in FIG. 38, the photodetector 1 </ b> B according to the second embodiment is the first in that the pixel unit is configured by one photodetecting element 30 and the reference unit is configured by one reference element 40. This is mainly different from the photodetector 1A of the embodiment.

The photodetector 1B includes a substrate 2B having a surface 2b, a light detection element 30, a reference element 40, a first dummy part 5, and a second dummy part 6. The thickness of the substrate 2B is, for example, about several hundred μm. The photodetecting element 30, the reference element 40, the first dummy portion 5, and the second dummy portion 6 are formed on the surface 2b of the substrate 2B.

When viewed from the Z-axis direction (thickness direction of the substrate 2B), the light detection element 30 and the reference element 40 are arranged so as to be aligned in the X-axis direction (direction perpendicular to the Z-axis) parallel to the surface 2b. ing. The photodetecting element 30 and the reference element 40 are adjacent to each other. In the photodetector 1B, one reference element 40 is used for compensation for one photodetector 30. The first dummy part 5 surrounds the light detection element 30 and the reference element 40 together with the second dummy part 6. The first dummy part 5 and the second dummy part 6 are adjacent to each other.

The circuit board 22B and a plurality of I / O pads 12 are provided on the substrate 2B. The circuit portion 22B is provided in a layered manner on the surface 2b side of the substrate 2B. The I / O pad 12 is composed of a metal film formed on the surface 2b of the substrate 2B. The circuit unit 22B includes an analog read circuit (signal read circuit) 13, an AD converter 14, a DSP (digital signal processor) 15, a digital interface 16, a timing generator 17, and a plurality of components that electrically connect each other. Wiring (not shown).

The analog readout circuit 13 is provided in a rectangular annular region when viewed from the Z-axis direction. The analog readout circuit 13 surrounds the light detection element 30 and the reference element 40 when viewed from the Z-axis direction. The DSP 15 and the timing generator 17 are arranged on both sides in the X-axis direction (direction orthogonal to the Z-axis) parallel to the surface 2 b with respect to the analog readout circuit 13. The digital interface 16 is arranged to line up with the DSP 15 in the Y-axis direction (direction orthogonal to the Z-axis and the X-axis) parallel to the surface 2b. The AD converter 14 is arranged so as to be aligned with the timing generator 17, the analog readout circuit 13, the DSP 15, and the digital interface 16 in the Y-axis direction. The plurality of I / O pads 12 are arranged along the outer edge of the surface 2b.

As shown in FIG. 39, the first region 3a and the second region 4a are adjacent to each other. The third region 5a and the fourth region 6a surround the entire outer edges of the first region 3a and the second region 4a. Specifically, the third region 5a has a shape in which one side is recessed by the size of the first region 3a, and the fourth region 6a has one side that is the size of the second region 4a. It has a concave shape. The third region 5a and the fourth region 6a are adjacent to each other so as to form a rectangular ring shape. The first region 3a and the second region 4a are located inside the rectangular ring.

The outer edge of the light detection element 30 overlaps with the outer edge of the first region 3a when viewed from the Z-axis direction. The outer edge of the reference element 40 overlaps with the outer edge of the second region 4a when viewed from the Z-axis direction. The outer edge of the first dummy portion 5 overlaps with the outer edge of the third region 5a when viewed from the Z-axis direction. The outer edge of the second dummy portion 6 overlaps with the outer edge of the fourth region 6a when viewed from the Z-axis direction.

The first dummy section 5 is composed of a plurality of first dummy elements 50. The second dummy part 6 is constituted by a plurality of second dummy elements 60. The plurality of first dummy elements 50 and the plurality of second dummy elements 60 are arranged in the third region 5a and the fourth region 6a so as to surround the light detection elements 30 and the reference elements 40 in a plurality of columns (here, four columns). Has been placed. As described above, the first dummy element 50 and the second dummy element 60 have surfaces along the outer edges of the first region 3a and the second region 4a so as to surround the entire outer edges of the first region 3a and the second region 4a. A plurality are arranged in 2a. That is, a plurality of the first dummy elements 50 and the second dummy elements 60 are arranged on the surface 2 a along the outer edges of the light detection elements 30 and the reference elements 40 so as to surround the light detection elements 30 and the reference elements 40.

The first dummy element 50 and the second dummy element 60 overlap the circuit portion 22B when viewed from the Z-axis direction (see FIG. 38). Specifically, the first dummy element 50 and the second dummy element 60 overlap the analog readout circuit 13 when viewed from the Z-axis direction.

In the photodetector 1B configured as described above, light is detected as follows. First, similarly to the photodetector 1 </ b> A, heat generated in the light absorption layer 76 is transmitted to the first resistance layer 75 through the separation layer 77. As a result of this heat, the temperature of the first resistance layer 75 increases and the electrical resistance decreases. A signal resulting from the change in electrical resistance is sent to the analog readout circuit 13 via the first wiring layers 71 and 72, the first electrode posts 32 and 33, and the first electrode pads 25 and 26. At this time, a signal due to a change in electrical resistance is also sent from the reference element 40 to the analog readout circuit 13. The analog readout circuit 13 amplifies and corrects a signal resulting from a change in the electrical resistance of the light detection element 30 and a signal resulting from a change in the electrical resistance of the reference element 40 and outputs the amplified signal. The AD converter 14 converts the signal amplified and corrected by the analog readout circuit 13 into a digital signal. The DSP 15 performs predetermined signal processing on the digital signal converted by the AD converter 14 and then outputs it to the digital interface 16. When a drive signal is input via the I / O pad 12, the timing generator 17 outputs a drive timing signal to the DSP 15. The digital interface 16 outputs a signal output from the DSP 15 to the outside via the I / O pad 12. The I / O pad 12 sequentially outputs signals generated by the digital interface 16. In the photodetector 1B, light is detected based on the difference between the signal from the light detection element 30 and the signal from the reference element 40.

As described above, according to the photodetector 1B of the second embodiment, the detection accuracy can be ensured while suppressing the complexity of the structure, similarly to the photodetector 1A of the first embodiment described above. .

In addition, when the pixel unit is configured by one photodetecting element 30 and the reference unit is configured by one reference element 40, a plurality of elements are arranged in a two-dimensional matrix in the manufacturing process of the photodetector 1B. Apart from the arrangement, it is necessary to optimize the dry etching conditions. In the photodetector 1B, the first dummy element 50 and the second dummy element 60 are arranged along the outer edges of the first area 3a and the second area 4a so as to surround the entire outer edges of the first area 3a and the second area 4a. Since a plurality of elements are arranged on the surface 2b of the substrate 2B, dry etching can be performed under the same conditions as in the case where a plurality of elements are arranged in a two-dimensional matrix. Therefore, the manufacturing process is simplified.

[Modification of Second Embodiment]
As shown in FIG. 40, only the third region 5a may surround the entire outer edges of the first region 3a and the second region 4a. That is, only the first dummy element 50 is disposed on the surface 2a of the substrate 2A along the outer edges of the first region 3a and the second region 4a so as to surround the entire outer edges of the first region 3a and the second region 4a. May be. Further, instead of the third region 5a, only the fourth region 6a may surround the entire outer edges of the first region 3a and the second region 4a. That is, instead of the first dummy element 50, only the second dummy element 60 is provided along the outer edges of the first area 3a and the second area 4a so as to surround the entire outer edges of the first area 3a and the second area 4a. A plurality of substrates may be arranged on the surface 2a of the substrate 2A.

In addition, as shown in FIG. 41, the third region 5a is on both sides in the Y-axis direction with respect to the first region 3a, and on the opposite side of the second region 4a with respect to the first region 3a. You may extend along the Y-axis direction and the X-axis direction. That is, the first dummy element 50 has the Y-axis direction and the X-axis direction on both sides in the Y-axis direction with respect to the first region 3a and on the opposite side of the first region 3a from the second region 4a, respectively. A plurality of them may be arranged along. Similarly, the fourth region 6a has a Y-axis direction and an X-axis direction on both sides in the Y-axis direction with respect to the second region 4a and on the opposite side of the second region 4a from the first region 3a, respectively. It may extend along. That is, the second dummy element 60 has a Y-axis direction and an X-axis direction on both sides in the Y-axis direction with respect to the second region 4a and on the opposite side of the second region 4a from the first region 3a, respectively. A plurality of them may be arranged along.

Further, instead of the fourth region 6a, the third region 5a is on both sides in the Y-axis direction with respect to the second region 4a, and on the opposite side of the first region 3a with respect to the second region 4a, respectively. You may extend along the Y-axis direction and the X-axis direction. That is, instead of the second dummy element 60, the first dummy element 50 is on both sides in the Y-axis direction with respect to the second region 4a and on the opposite side of the second region 4a from the first region 3a. A plurality of them may be arranged along the Y-axis direction and the X-axis direction, respectively. Similarly, instead of the third region 5a, the fourth region 6a is on both sides in the Y-axis direction with respect to the first region 3a, and on the opposite side of the second region 4a with respect to the first region 3a, respectively. , And may extend along the Y-axis direction and the X-axis direction. That is, instead of the first dummy element 50, the second dummy element 60 is located on both sides in the Y-axis direction with respect to the first region 3a and on the opposite side of the first region 3a from the second region 4a. A plurality of them may be arranged along the Y-axis direction and the X-axis direction, respectively.

42, the first region 3a and the second region 4a may be separated from each other. In this case, each of the third region 5a and the fourth region 6a surrounds each of the first region 3a and the second region 4a. That is, each of the first dummy element 50 and the second dummy element 60 surrounds each of the first region 3a and the second region 4a along the outer edge of the first region 3a and the outer edge of the second region 4a. A plurality of surfaces are arranged on the surface 2a.

Also, as shown in FIG. 43, only the third region 5a may surround each of the first region 3a and the second region 4a. That is, only the first dummy element 50 is disposed on the surface 2a along the outer edge of the first region 3a and the outer edge of the second region 4a so as to surround each of the first region 3a and the second region 4a. It may be. Further, instead of the third region 5a, only the fourth region 6a may surround each of the first region 3a and the second region 4a. That is, instead of the first dummy element 50, only the second dummy element 60 surrounds each of the first region 3a and the second region 4a, and the outer edge of the first region 3a and the outer edge of the second region 4a, respectively. A plurality of surfaces may be arranged on the surface 2a.

As shown in FIG. 44, the third region 5a has a Y-axis direction on both sides in the Y-axis direction with respect to the first region 3a and on both sides in the X-axis direction with respect to the first region 3a. And may extend along the X-axis direction. That is, the first dummy element 50 is along the Y-axis direction and the X-axis direction on both sides in the Y-axis direction with respect to the first region 3a and on both sides in the X-axis direction with respect to the first region 3a. A plurality of them may be arranged. Similarly, the fourth region 6a extends along the Y-axis direction and the X-axis direction on both sides in the Y-axis direction with respect to the second region 4a and on both sides in the X-axis direction with respect to the second region 4a, respectively. It may be extended. That is, the second dummy element 60 is along the Y-axis direction and the X-axis direction on both sides in the Y-axis direction with respect to the second region 4a and on both sides in the X-axis direction with respect to the second region 4a, respectively. A plurality of them may be arranged.

Further, in place of the fourth region 6a, the third region 5a is in the Y-axis direction on both sides in the Y-axis direction with respect to the second region 4a and on both sides in the X-axis direction with respect to the second region 4a. And may extend along the X-axis direction. In other words, instead of the second dummy element 60, the first dummy element 50 is provided on both sides in the Y-axis direction with respect to the second region 4a and on both sides in the X-axis direction with respect to the second region 4a. A plurality may be arranged along the axial direction and the X-axis direction. Similarly, instead of the third region 5a, the fourth region 6a has a Y-axis on both sides in the Y-axis direction with respect to the first region 3a and on both sides in the X-axis direction with respect to the first region 3a. May extend along the direction and the X-axis direction. In other words, instead of the first dummy element 50, the second dummy element 60 is Y on both sides in the Y-axis direction with respect to the first region 3a and on both sides in the X-axis direction with respect to the first region 3a. A plurality may be arranged along the axial direction and the X-axis direction.

In addition, although the example in which the first dummy element 50 and the second dummy element 60 overlap with the analog readout circuit 13 when viewed from the Z-axis direction is shown, the first dummy element 50 and the second dummy element 60 are When viewed from the Z-axis direction, the analog readout circuit 13 may not overlap.

1A, 1B ... photodetector, 2A, 2B ... substrate, 2a, 2b ... surface, 3a ... first region, 4a ... second region, 5a ... third region, 6a ... fourth region, 7 ... signal readout circuit, DESCRIPTION OF SYMBOLS 13 ... Analog readout circuit (signal readout circuit), 22A, 22B ... Circuit part, 30 ... Photodetection element, 31 ... 1st film body, 40 ... Reference element, 41 ... 2nd film body, 50 ... 1st dummy element, 51 ... 3rd film body, 60 ... 2nd dummy element, 61 ... 4th film body, S1, S2, S3, S4 ... Air gap.

Claims (10)

1. A substrate having a surface;
   A photodetecting element having a first film body disposed on the surface via a gap;
   A reference element having a second film body disposed on the surface via a gap;
   A dummy element having a film body disposed on the surface through a gap;
   A circuit unit provided on the substrate and electrically connected to the photodetecting element and the reference element;
   The light detection element is an element for detecting light based on a temperature change due to light reception, and is disposed in the first region of the surface.
   The reference element is an element for compensating for a temperature change due to a factor other than the light reception in the light detection element, and is disposed in the second region of the surface.
   The dummy element is disposed in an area other than the first area and the second area on the surface along at least one of an outer edge of the first area and an outer edge of the second area,
   The photo detector, wherein the dummy element is electrically insulated from the circuit unit.
2. A plurality of the dummy elements are arranged in the region other than the first region and the second region on the surface so as to be arranged in a direction intersecting at least one of the outer edge of the first region and the outer edge of the second region. The photodetector of claim 1.
3. The dummy element is further disposed in a region between the first region and the second region on the surface along at least one of an outer edge of the first region and an outer edge of the second region. The photodetector according to claim 1.
4. The dummy element is disposed along an outer edge of the second region;
   The film body of the dummy element disposed along the outer edge of the second region has the same shape as the second film body of the reference element when viewed from the thickness direction of the substrate. The photodetector according to any one of claims 1 to 3.
5. The dummy element is disposed along an outer edge of the first region;
   The film body of the dummy element disposed along the outer edge of the first region has the same shape as the first film body of the photodetecting element when viewed from the thickness direction of the substrate. The photodetector according to any one of claims 1 to 4.
6. The light according to any one of claims 1 to 5, wherein a plurality of the dummy elements are arranged on the surface along an outer edge of the second region so as to surround the second region in at least one row. Detector.
7. A plurality of the dummy elements are arranged on the surface along the outer edges of the first region and the second region so as to surround the first region and the second region in at least one row. The photodetector according to any one of 6.
8. A plurality of the dummy elements are arranged on the surface along the outer edge of the first region and the outer edge of the second region so as to surround each of the first region and the second region in at least one row. The photodetector according to any one of claims 1 to 6.
9. The film body of the dummy element arranged along the outer edge of the second region has the same shape as the second film body of the reference element when viewed from the thickness direction of the substrate. ,
   The film body of the dummy element disposed along the outer edge of the first region has the same shape as the first film body of the photodetecting element when viewed from the thickness direction of the substrate. The photodetector according to any one of claims 6 to 8.
10. The circuit unit includes a signal readout circuit,
    The photodetector according to any one of claims 1 to 9, wherein the dummy element overlaps the signal readout circuit when viewed in the thickness direction of the substrate.

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