JP7142471B2 - photodetector - Google Patents

Description

The present invention relates to photodetectors.

A known photodetector includes a photodetection 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 a factor other than the light reception in the photodetection element. (See Patent Document 1, for example).

JP 2015-45641 A

In order to secure the detection accuracy of the photodetector as described above, for example, it is conceivable to devise a method of signal processing. However, in that case, there is a risk that the structure of the circuit section provided on the substrate that supports the photodetector and the reference device, and thus the structure of the photodetector, will be complicated.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a photodetector capable of ensuring detection accuracy while suppressing complication of the structure.

A photodetector of the present invention includes a substrate having a surface, a photodetector having a first film disposed on the surface with a gap therebetween, and a second film disposed on the surface with a gap therebetween. a reference element, a dummy element having a film disposed on a surface with a gap therebetween, and a circuit section provided on a substrate and electrically connected to the photodetector and the reference element, wherein The element is an element for detecting light based on a temperature change due to light reception, and is arranged in the first region of the surface, and the reference element compensates temperature changes due to factors other than light reception in the light detection element. The dummy element is arranged in a second region of the surface, and the dummy element is arranged in a region other than the first region and the second region of the surface, and is located on the outer edge of the first region and the outer edge of the second region. and the dummy element is electrically insulated from the circuit section.

In this photodetector, when the dummy element is arranged along the outer edge of the first region, for example, compared to a case where a space is formed without the dummy element, at least one The first film of the photodetector is placed in a uniform environment, resulting in improved detection accuracy of the at least one photodetector. In addition, when the dummy element is arranged along the outer edge of the second region, for example, compared to the case where the dummy element does not exist and the space is formed, at least one of the reference elements The two membrane bodies are placed in a uniform environment, resulting in improved detection accuracy of the at least one reference element. On the other hand, since the dummy element is electrically insulated from the circuit section, a circuit structure for electrically connecting the dummy element to the circuit section is not required. Therefore, according to this photodetector, detection accuracy can be ensured while suppressing complication of the structure.

In the photodetector of the present invention, a plurality of dummy elements are arranged in a region of the surface other than the first region and the second region 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. may be placed. According to this configuration, when the dummy element is arranged along the outer edge of the first region, the first film body of at least one photodetector element is placed in a more uniform environment, and as a result, at least The detection accuracy of one photodetector is further improved. Further, when the dummy element is arranged along the outer edge of the second region, the second film of the at least one reference element is placed in a more uniform environment, and as a result, the at least one reference element Detection accuracy is further improved.

In the photodetector of the present invention, the dummy element is further arranged on the surface between the first region and the second region along at least one of the outer edge of the first region and the outer edge of the second region. may According to this configuration, in addition to the dummy element being arranged along the outer edge of the first region, when the dummy element is arranged in the region between the first region and the second region, The first film of the at least one photodetector is placed in a more uniform environment, and as a result, the detection accuracy of the at least one photodetector is further improved. Further, in addition to the dummy element being arranged along the outer edge of the second region, when the dummy element is arranged in the region between the first region and the second region, at least one reference The second membrane of the element is placed in a more uniform environment, resulting in even better detection accuracy of the at least one reference element.

In the photodetector of the present invention, the dummy element is arranged along the outer edge of the second region, and the film body of the dummy element arranged along the outer edge of the second region is In this case, 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, detection accuracy of at least one reference element is further improved.

In the photodetector of the present invention, the dummy element is arranged along the outer edge of the first region, and the film body of the dummy element arranged along the outer edge of the first region is In this case, it may have the same shape as the first film body of the photodetector. According to this configuration, the first film body of at least one photodetector is placed in a more uniform environment, and as a result, the detection accuracy of at least one photodetector is further improved.

In the photodetector of the present invention, 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, detection accuracy of at least one reference element is improved.

In the photodetector of the present invention, a plurality of dummy elements may be arranged on the surface along outer edges of the first and second regions so as to surround the first and second regions in at least one row. According to this configuration, the second film body of at least one reference element and the first film body of at least one photodetector 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 photodetector is improved.

In the photodetector of the present invention, a plurality of dummy elements are arranged on the surface along the outer edge of the first area and the outer edge of the second area so as to surround each of the first area and the second area in at least one row. may have been According to this configuration, the second film body of at least one reference element and the first film body of at least one photodetector 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 photodetector is improved.

In the photodetector of the present invention, the film of the dummy element arranged along the outer edge of the second region has the same shape as the second film of the reference element when viewed from the thickness direction of the substrate. The film body of the dummy element arranged along the outer edge of the first region may have the same shape as the first film body of the photodetector when viewed from the thickness direction of the substrate. . According to this configuration, the second film body of the at least one reference element and the first film body of the at least one photodetector element are placed in a more uniform environment, thereby improving the detection accuracy of the at least one reference element. , and the detection accuracy of the at least one photodetector is further improved.

In the photodetector of the present invention, the circuit section may include the signal readout circuit, and the dummy element may overlap 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 complication of the structure of the photodetector.

ADVANTAGE OF THE INVENTION According to this invention, the photodetector which can ensure detection accuracy can be provided, suppressing complication of a structure.

2 is a plan view of the photodetector of the first embodiment; FIG. 2 is a diagram showing each region on the surface of the substrate of FIG. 1; FIG. 3 is a plan view of a photodetector element, a reference element, a first dummy element, and a second dummy element arranged in each region of FIG. 2; FIG. 4 is a perspective view of the photodetector of FIG. 3; FIG. FIG. 5 is a plan view of the photodetector of FIG. 4; 5 is a cross-sectional view of the photodetector of FIG. 4; FIG. It is a figure which shows the principle of an optical resonance structure. Figure 4 is a perspective view of the reference element of Figure 3; FIG. 9 is a plan view of the reference element of FIG. 8; FIG. 9 is a cross-sectional view of the reference element of FIG. 8; 4 is a perspective view of a first dummy element of FIG. 3; FIG. FIG. 12 is a plan view of the first dummy element of FIG. 11; FIG. 12 is a cross-sectional view of the first dummy element of FIG. 11; 4 is a perspective view of a second dummy element of FIG. 3; FIG. 15 is a plan view of the second dummy element of FIG. 14; FIG. 15 is a cross-sectional view of the second dummy element of FIG. 14; FIG. 7A and 7B are views showing a method of manufacturing the photodetector of FIG. 6; FIG. 7A and 7B are views showing a method of manufacturing the photodetector of FIG. 6; FIG. 7A and 7B are views showing a method of manufacturing the photodetector of FIG. 6; FIG. 7A and 7B are views showing a method of manufacturing the photodetector of FIG. 6; FIG. 7A and 7B are views showing a method of manufacturing the photodetector of FIG. 6; FIG. 7A and 7B are views showing a method of manufacturing the photodetector of FIG. 6; FIG. 7A and 7B are views showing a method of manufacturing the photodetector of FIG. 6; FIG. 7A and 7B are views showing a method of manufacturing the photodetector of FIG. 6; FIG. 7A and 7B are views showing a method of manufacturing the photodetector of FIG. 6; FIG. 7A and 7B are views showing a method of manufacturing the photodetector of FIG. 6; FIG. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 1st Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 1st Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 1st Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 1st Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 1st Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 1st Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 1st Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 1st Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 1st Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 1st Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 1st Embodiment. FIG. 5 is a plan view of a photodetector of a second embodiment; FIG. 39 is a diagram showing regions on the surface of the substrate of FIG. 38; It is a figure which shows each area|region in the surface of the board|substrate of the modification of 2nd Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 2nd Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 2nd Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 2nd Embodiment. It is a figure which shows each area|region in the surface of the board|substrate of the modification of 2nd Embodiment.

Preferred embodiments of the present invention will now be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted.

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

When viewed from the Z-axis direction (the thickness direction of the substrate 2A), the pixel section 3 and the reference section 4 are arranged side by side in the X-axis direction (the direction perpendicular to the Z-axis) parallel to the surface 2a. there is The pixel section 3 and the reference section 4 are separated from each other. The first dummy portion 5 surrounds the pixel portion 3 . A second dummy section 6 surrounds the reference section 4 . The first dummy section 5 and the second dummy section 6 are adjacent to each other.

A circuit portion 22A and a plurality of I/O pads 12 are provided on the substrate 2A. The circuit section 22A is provided in layers 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 section 22A has a signal readout circuit 7 and a plurality of wirings (not shown) that electrically connect each component to each other. The signal readout circuit 7 includes a correction circuit 8, a readout circuit 9, and a plurality of shift registers (scanning circuits) 11a, 11b, 11c.

The correction circuit 8 is arranged on the side opposite to the pixel section 3 with respect to the reference section 4 . The readout circuit 9 is arranged on the side opposite to the reference section 4 with respect to the correction circuit 8 . The shift register 11a is arranged so as to be aligned with the pixel section 3 in the Y-axis direction (the 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 section 4 in the Y-axis direction. The shift register 11c is arranged on the opposite side of the readout circuit 9 from the correction circuit 8. FIG. A plurality of I/O pads 12 are arranged along the outer edge of surface 2a.

As shown in FIG. 2, the surface 2a of the substrate 2A includes a first area 3a, a second area 4a, a third area 5a and a fourth area 6a. The pixel section 3 is arranged in the first region 3a of the surface 2a. The reference portion 4 is arranged in the second region 4a of the surface 2a. The first dummy portion 5 is arranged in the third region 5a of the surface 2a. The second dummy portion 6 is arranged in the fourth region 6a of the surface 2a.

The first region 3a and the second region 4a are arranged side by side 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, for example, a rectangular shape. 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 annular 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 annular 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 portion 3 has, for example, a rectangular shape when viewed from the Z-axis direction. The outer edge of the pixel section 3 overlaps the outer edge of the first region 3a when viewed from the Z-axis direction. The outer edge of the reference section 4 has, for example, a rectangular shape when viewed from the Z-axis direction. The outer edge of the reference portion 4 overlaps 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 annular shape when viewed from the Z-axis direction. The outer and inner edges of the first dummy portion 5 respectively overlap with the outer and inner edges of the third region 5a when viewed from the Z-axis direction. The second dummy portion 6 has, for example, a rectangular annular shape when viewed from the Z-axis direction. The outer and inner edges of the second dummy portion 6 respectively overlap with the outer and inner edges 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 section 3 is composed of a plurality of photodetectors 30 . Each photodetector element 30 is an element for detecting light based on temperature change due to light reception. A plurality of photodetecting elements 30 are arranged in the first region 3a so as to be arranged in a two-dimensional matrix. The photodetector elements 30 are arranged, for example, in a size of about 64 columns×64 rows to 128 columns×128 rows. The outer shape of the photodetector 30 when viewed from the Z-axis direction is, for example, rectangular.

The reference section 4 is composed of a plurality of reference elements 40 . Each reference element 40 is an element for compensating temperature changes due to factors other than light reception in the photodetector element 30 . A 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 so as to have, for example, about 16 columns×64 rows to 16 columns×128 rows. The external shape of the reference element 40 when viewed from the Z-axis direction is, for example, rectangular. In the photodetector 1A, one reference element 40 is used to compensate for a plurality of photodetection elements 30 (for example, a plurality of photodetection 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 section 3 in a plurality of columns (here, four columns). In this manner, a plurality of first dummy elements 50 are arranged on surface 2a along the outer edge of first region 3a so as to surround 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 section 3 so as to surround the pixel section 3 . The outer shape of the first dummy element 50 when viewed in the Z-axis direction is, for example, rectangular.

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 section 4 in a plurality of rows (here, four rows). 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 section 4 so as to surround the reference section 4 . The outer shape of the second dummy element 60 when viewed in the Z-axis direction is, for example, rectangular.

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

[Structure of photodetector]
As shown in FIG. 4, the photodetector 30 has a first film body 31 and a pair of first electrode posts 32 and 33 .

The first film body 31 is arranged on the surface 2a of the substrate 2A with a gap S1 interposed therebetween. The first film body 31 is arranged 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 has a light receiving portion 34, a pair of first connecting portions 35 and 36, and a pair of first beam portions 37 and 38. . The light receiving portion 34, the pair of first connection portions 35 and 36, and the pair of first beam portions 37 and 38 are integrally formed. The first connection portions 35 and 36 are located at diagonal corners of the outer shape of the first film body 31 . Each of the first connection portions 35 and 36 has, for example, a rectangular shape when viewed from the Z-axis direction. Thus, in the photodetector 1A, the external shape of the first film body 31 when viewed from the Z-axis direction is the light receiving portion 34, the pair of first connecting portions 35 and 36, and the pair of first beam portions 37. , 38 to form a rectangle. The external shape of the first film body 31 when viewed from the Z-axis direction includes the light receiving portion 34, the pair of first connection portions 35 and 36, the pair of first beam portions 37 and 38, and a first It is the outline of the entire first film body 31 including the slits 31a and 31b.

The first beam portion 37 is arranged 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 . First slits 31 a are continuously formed between the light receiving portion 34 and the first connecting portion 35 and between the light receiving portion 34 and the first beam portion 37 . The first beam portion 38 is arranged 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 . A first slit 31b is continuously formed between the light receiving portion 34 and the first connecting portion 36 and between the light receiving portion 34 and the first beam portion 38 . Each width of the first beam portions 37 and 38 is, for example, about several μm. Each length of the first beam portions 37 and 38 is, for example, about several tens to several hundred μm. The width of each of the first slits 31a and 31b is, for example, about several μm.

The first electrode post 32 is arranged between the substrate 2A and the first connection portion 35 . The first electrode post 32 has a tubular shape that widens from the substrate 2A toward the first film body 31 . The first electrode post 33 is arranged between the substrate 2A and the first connection portion 36 . The first electrode post 33 has a tubular shape that widens from the substrate 2A 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 photodetector 30. As shown in FIG. II, II-II, III-III, IV-IV, and VV in FIG. 6 are respectively the II line, II-II line, III-III line, IV-IV line, and V in FIG. - It is sectional drawing along V line. 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. , contains

As shown in FIGS. 5 and 6, when viewed from the Z-axis direction, the first wiring layers 71 and 72 face each other in the light receiving section 34 with the first gap G1 interposed therebetween. The first gap G1 extends along the first line L1. The first line L1 extends between diagonal corners facing each other across the center of gravity position C1 of the first film body 31 when viewed in the Z-axis direction. Specifically, when viewed from the Z-axis direction, the first line L1 is along the first diagonal line D1 that passes through the center of gravity position C1 of the first film body 31 and connects the first connecting portions 35 and 36. It extends in a meandering shape. The first line L1 has a meandering portion. In the light receiving portion 34, the meandering portion extends to one side of the light receiving portion 34, then turns back, for example, 180°, extends to the other side of the light receiving portion 34, turns back, for example, 180°, and extends to the other side of the light receiving portion 34. It is constructed by repeating extending to one side.

In the photodetector 30, one side refers to one side (for example, the side where the first beam portion 37 exists) with respect to the first diagonal D1 when viewed from the Z-axis direction, and the other side and the other side. refers to the side opposite to one side with respect to the first diagonal line D1 (for example, the side on which the first beam portion 38 exists) when viewed from the Z-axis direction.

The first wiring layers 71 and 72 are formed elongated in the direction along the first line L1 in the light receiving section 34 . That is, when viewed from the Z-axis direction, in the light receiving section 34, the lengths of the first wiring layers 71 and 72 in the direction along the first line L1 are the same as the lengths of the first wiring layers 71 and 72 in the direction perpendicular to the first line L1. It is larger than the width of each of the wiring layers 71 and 72 . A direction perpendicular to the first line L1 means a direction perpendicular to a tangent line 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 directions perpendicular to the first line L1 are 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 section 34 is, for example, about several tens to several hundred 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 hundred nm.

The first wiring layer 71 extends from the light receiving portion 34 to the first connection portion 35 via the first beam portion 37 . The first wiring layer 71 is formed on the first electrode post 32 at the first connecting 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 section 34 to the first connection section 36 via the first beam section 38 . The first wiring layer 72 is formed on the first electrode post 33 at the first connecting portion 36 . The first wiring layer 72 is electrically connected to the first electrode posts 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 applied to the light receiving section 34, the first beam sections 37 and 38, and the first connecting sections 35 and 36 so as to cover the surface of each of the first wiring layers 71 and 72 opposite to the substrate 2A. formed across. The insulating layer 73 exposes the surface of each of the first wiring layers 71 and 72 opposite to the substrate 2A and exposes the area along the first line L1. is formed on the surface opposite to the The insulating layer 73 covers the side surfaces of the first wiring layers 71 and 72 at the first connecting 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 each of the first wiring layers 71 and 72 on the side of the substrate 2A. It is The insulating layer 74 covers the substrate 2A side surfaces of the first wiring layers 71 and 72 and the outer surfaces 32a and 33a of the first electrode posts 32 and 33 at the first connecting portions 35 and 36, respectively. Each thickness 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) or the like.

The first resistance layer 75 is formed in the light receiving section 34 so as to cover the insulating layer 73 from the side opposite to the substrate 2A. In the light receiving section 34, the first resistance layer 75 is in contact with a region along the first line L1 on the surface of each of the first wiring layers 71 and 72 opposite to the substrate 2A. That is, the first resistance layer 75 is electrically connected to each of the first wiring layers 71 and 72 in the light receiving section 34 . The first resistive 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 hundred nm. The material of the first resistance layer 75 is, for example, amorphous silicon (a-Si) whose electrical resistivity changes greatly with temperature changes. Thus, the light receiving section 34 includes electrical connection regions 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 on the light receiving section 34 but also on the first connecting sections 35 and 36 . The first resistance layer 75 is not formed on portions of the first beam portions 37 and 38 excluding both ends 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 2a of the substrate 2A in the light receiving section 34. As shown in FIG. The light absorption layer 76 is arranged on the side opposite to the substrate 2A with respect to the first resistance layer 75 . The light absorption layer 76 extends over the entire area of the light receiving section 34 when viewed from the Z-axis direction. The thickness of the light absorption layer 76 is, for example, about ten and several nm. The material of the light absorbing layer 76 is, for example, _WSi2 or Ti.

The separation layer 77 is positioned between the first resistance layer 75 and the light absorption layer 76 in the light receiving section 34 , the first beam section 37 and the first beam section 38 , and the first connection layer 34 . It is formed over the portion 35 and the first connecting portion 36 . The thickness of the isolation layer 77 is greater 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 isolation layer 77 is, for example, about several hundred nm. The material of the isolation layer 77 is, for example, a silicon nitride film (SiN).

A through hole 31 c is formed in the first film body 31 . The through hole 31c is a hole through which an etching gas for removing the sacrificial layer 39, which will be 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 positioned, for example, at the center-of-gravity position 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 section 34 in the Z-axis direction (thickness direction of the semiconductor substrate 21). The light reflecting layer 24 faces the light absorbing layer 76 in the Z-axis direction, and forms an optical resonance structure together with the light absorbing layer 76 . The thickness of the light reflecting 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 that has a high reflectance 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 portion 36 in the Z-axis direction. The light reflecting 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 positioned at diagonal corners of the contour. 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 section 22A by wiring. The thickness of each of the first electrode pads 25 and 26 is, for example, about several hundred nm. The material of each of the first electrode pads 25 and 26 is, for example, a conductive metal material such as Al.

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

Through holes 27 a and 27 b are formed in the insulating layer 27 so as to face the first connection portions 35 and 36 . In other words, the insulating layer 27 covers the outer edges of the first electrode pads 25 and 26 so that the surfaces of the first electrode pads 25 and 26 opposite to the semiconductor substrate 21 are partially exposed.

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

Next, the optical resonant structure will be described in detail. As shown in FIG. 7, incident light A (having a wavelength of λ) incident on the light absorption layer 76 is partly reflected by the light absorption layer 76 as reflected light B1, and the other part is reflected by the light absorption layer 76. 76 is permeable. Another portion of the incident light A transmitted through the light absorption layer 76 is reflected by the light reflection layer 24 as reflected light B2. The reflected light B<b>1 and the reflected light B<b>2 interfere with each other and are canceled on the reflecting surface of the light absorption layer 76 . As a result, the incident light A is absorbed by the reflecting surface of the light absorption layer 76 . Heat is generated in the light absorbing layer 76 by the energy of the incident light A that is absorbed.

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

Also, the optical distance t is set so that 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°. Therefore, on the reflecting surface of the light absorption layer 76, the reflected light B1 and the reflected light B2 are efficiently interfered and canceled. Therefore, the absorption rate of the incident light A is improved. Thus, the light reflection layer 24 and the light absorption layer 76 constitute an optical resonance structure. When viewed from the Z-axis direction, the larger the overlapping area 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. differ mainly from The reference element 40 has a second film body 41 and a pair of second electrode posts 42 and 43 .

The second film body 41 is arranged on the surface 2a of the substrate 2A via the gap S2. The second film body 41 is arranged 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 has a body portion 44, a pair of second connection portions 45 and 46, and a pair of second beam portions 47 and 48. . The body portion 44, the pair of second connection portions 45 and 46, and the pair of second beam portions 47 and 48 are integrally formed. The second connection portions 45 and 46 are positioned at diagonal corners of 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 external shape of the second film body 41 when viewed from the Z-axis direction is 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 includes the body portion 44, the pair of second connection portions 45 and 46, the pair of second beam portions 47 and 48, and a second It is the outline of the entire second film body 41 including the slits 41a and 41b.

The second beam portion 47 is arranged between the body portion 44 and the second connection portion 45 . The second beam portion 47 extends along the outer edge of the body portion 44 on one side of the body portion 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 body portion 44 at a position near the second connection portion 45 . That is, the second beam portion 47 is shorter than the first beam portion 37 . Second slits 41 a are continuously formed between the body portion 44 and the second connection portion 45 and between the body portion 44 and the second beam portion 47 . The second beam portion 48 is arranged between the body portion 44 and the second connection portion 46 . The second beam portion 48 extends along the outer edge of the body portion 44 on the other side of the body portion 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 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 . A second slit 41 b is continuously formed between the body portion 44 and the second connection portion 46 and between the body portion 44 and the second beam portion 48 . Each width 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 arranged between the substrate 2A and the second connection portion 45 . The second electrode post 42 has a tubular shape that widens from the substrate 2A toward the second film body 41 . The second electrode post 43 is arranged between the substrate 2A and the second connection portion 46 . The second electrode post 43 has a tubular shape that widens from the substrate 2A 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. As shown in FIG. II, II-II, III-III, IV-IV, and VV in FIG. 10 correspond to the II line, II-II line, III-III line, IV-IV line, and V in FIG. 9, respectively. - It is sectional drawing along V line. 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 FIG.

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

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

The second wiring layers 81 and 82 are formed elongated in the direction along the second line L2 in the body portion 44 . That is, when viewed from the Z-axis direction, the lengths of the second wiring layers 81 and 82 in the direction along the second line L2 in the body portion 44 are the same as the lengths of the second wiring layers 81 and 82 in the direction perpendicular to the second line L2. It is larger than the width of each of the wiring layers 81 and 82 . A direction perpendicular to the second line L2 means a direction perpendicular to a tangent line 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 directions perpendicular to the second line L2 are 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 body portion 44 is, for example, about several tens to several hundred 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 hundred nm.

The second wiring layer 81 extends from the body portion 44 to the second connecting portion 45 via the second beam portion 47 . The second wiring layer 81 is formed on the second electrode post 42 at 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 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 at 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 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 each of the second wiring layers 81 and 82 opposite to the substrate 2A. formed across. The insulating layer 83 exposes the surface of each of the second wiring layers 81 and 82 opposite to the substrate 2A and exposes the area along the second line L2. is formed on the surface opposite to the The insulating layer 83 covers the side surfaces of the second wiring layers 81 and 82 at the second connection portions 45 and 46 . The insulating layer 84 is formed over the 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 each of the second wiring layers 81 and 82 on the substrate 2A side. It is The insulating layer 84 covers the substrate 2A side surfaces of the second wiring layers 81 and 82 and the outer surfaces 42a and 43a of the second electrode posts 42 and 43 at 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 on the 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 area along the second line L2 on the surface of each of the second wiring layers 81 and 82 on the side opposite to the substrate 2A in the body portion 44 . That is, the second resistance layer 85 is electrically connected to each of the second wiring layers 81 and 82 in the body portion 44 . The second resistive 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 hundred nm. The material of the second resistance layer 85 is, for example, amorphous silicon (a-Si) whose electrical resistivity changes greatly with temperature changes. In this manner, the body portion 44 includes electrical connection regions 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 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 excluding both ends 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 body portion 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 resistance layer 85 and the insulating layer 83 opposite to the substrate 2A. formed across. The thickness of the separation layer 87 is greater 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 isolation layer 87 is, for example, about several hundred nm. The material of the isolation layer 87 is, for example, a silicon nitride film (SiN).

A through hole 41 c is formed in the second film body 41 . The through hole 41c is a hole through which an etching gas for removing the 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 positioned, for example, at the center-of-gravity position 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.

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 section 22A by wiring. The thickness of each of the second electrode pads 28 and 29 is, for example, about several hundred nm. The material of each of the second electrode pads 28 and 29 is, for example, a conductive metal material such as Al.

Through holes 27 c and 27 d are further formed in the insulating layer 27 so as to face the second connection portions 45 and 46 . In other words, the insulating layer 27 covers the outer edges of the second electrode pads 28 and 29 so that the surfaces of the second electrode pads 28 and 29 opposite to the semiconductor substrate 21 are partially exposed.

The second electrode post 42 is joined to the second electrode pad 28 in a state in which the protruding portion provided at the end 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 in which the projection 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 section 22A. Also, 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 does not have the light absorption layer 76 and is electrically insulated from the circuit section 22A. Mainly different. The first dummy element 50 has a third film body 51 and a pair of third electrode posts 52 and 53 .

The third film body 51 is arranged on the surface 2a of the substrate 2A with a gap S3 interposed therebetween. The third film body 51 is arranged 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 has a 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 body portion 54, the pair of third connection portions 55 and 56, and the pair of third beam portions 57 and 58 are integrally formed. The third connection portions 55 and 56 are positioned at diagonal corners of the outer shape of the third film body 51 . Each of the third connection portions 55 and 56 has, for example, a rectangular shape when viewed from the Z-axis direction. Thus, in the photodetector 1A, the outer shape of the third film body 51 when viewed from the Z-axis direction is 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 rectangle. The external shape of the third film body 51 when viewed from the Z-axis direction includes the main body portion 54, the pair of third connection portions 55 and 56, the pair of third beam portions 57 and 58, and the third It is the external shape of the whole 3rd film body 51 containing slits 51a and 51b.

The third beam portion 57 is arranged between the body portion 54 and the third connection portion 55 . The third beam portion 57 extends along the outer edge of the body portion 54 on one side of the 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 body portion 54 at a position near the third connection portion 56 . Third slits 51 a are continuously formed between the body portion 54 and the third connection portion 55 and between the body portion 54 and the third beam portion 57 . The third beam portion 58 is arranged between the body portion 54 and the third connection portion 56 . The third beam portion 58 extends along the outer edge of the body portion 54 on the other side of the 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 body portion 54 at a position near the third connection portion 55 . Third slits 51 b are continuously formed between the body portion 54 and the third connection portion 56 and between the body portion 54 and the third beam portion 58 . Each width 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 hundred μm. Each width of the third slits 51a and 51b is, for example, about several μm.

13 is a cross-sectional view of the first dummy element 50. FIG. II, II-II, III-III, IV-IV, and VV in FIG. 13 correspond to the II line, II-II line, III-III line, IV-IV line, and V in FIG. 12, respectively. - It is sectional drawing along V line. As shown in FIG. 13, the third film body 51 differs from the first film body 31 only in that it does not have the light absorption layer 76, and the other structures are the same as those of the first film body 31. are identical. A detailed description of the third film body 51 is omitted.

As shown in FIG. 13, the surface 2a of the substrate 2A is completely covered with the insulating layer 27 in the region facing the first dummy element 50. As shown in FIG. 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 section 22A. Also, the third film body 51 is supported on the surface 2a of the substrate 2A by means of the third electrode posts 52 and 53 via the gap S3.

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

The fourth film body 61 is arranged on the surface 2a of the substrate 2A with a gap S4 interposed therebetween. The fourth film body 61 is arranged 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 has a 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 body portion 64, the pair of fourth connection portions 65 and 66, and the pair of fourth beam portions 67 and 68 are integrally formed. The fourth connection portions 65 and 66 are located at diagonal corners of the outer shape of the fourth film body 61 . Each of the fourth connection portions 65 and 66 has, for example, a rectangular shape when viewed from the Z-axis direction. Thus, in the photodetector 1A, 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 are formed in a rectangular shape. The outer shape of the fourth film body 61 when viewed from the Z-axis direction includes the body portion 64, the pair of fourth connection portions 65 and 66, the pair of fourth beam portions 67 and 68, and a fourth It is the outline of the entire fourth film body 61 including the slits 61a and 61b.

The fourth beam portion 67 is arranged between the body portion 64 and the fourth connection portion 65 . The fourth beam portion 67 extends along the outer edge of the body portion 64 on one side of the 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 . Fourth slits 61 a are continuously formed between the body portion 64 and the fourth connection portion 65 and between the body portion 64 and the fourth beam portion 67 . The fourth beam portion 68 is arranged between the body portion 64 and the fourth connection portion 66 . The fourth beam portion 68 extends along the outer edge of the body portion 64 on the other side of the 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 . Fourth slits 61 b are continuously formed between the body portion 64 and the fourth connection portion 66 and between the body portion 64 and the fourth beam portion 68 . Each width 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, approximately 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. As shown in FIG. II, II-II, III-III, IV-IV, and VV in FIG. 16 correspond to the II line, II-II line, III-III line, IV-IV line, and V in FIG. 15, respectively. - It is sectional drawing along V line. As shown in FIG. 16, the structure of the fourth film body 61 is the same as that of the second film body 41 . A detailed description of the fourth film body 61 is omitted.

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

[Substrate configuration]
As shown in FIGS. 6, 10, 13 and 16, the substrate 2A has a semiconductor substrate 21, a circuit section 22A, and an insulating layer 23. As shown in FIGS. The material of the semiconductor substrate 21 is silicon, for example. The circuit section 22A is provided in layers 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 is flat. and a plurality of wirings for electrically connecting 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 section 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 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 arranged on the shift register 11a side with respect to the pixel section 3 overlaps with the shift register 11a. Further, when viewed from the Z-axis direction, the second dummy element 60 arranged on the shift register 11b side with respect to the reference unit 4 overlaps with the shift register 11b. The second dummy element 60 arranged on the correction circuit 8 side with respect to the reference unit 4 overlaps the correction circuit 8 when viewed from the Z-axis direction. The second dummy element 60 arranged on the correction circuit 8 side with respect to the reference section 4 may also overlap the readout circuit 9 . Note that, when the dummy element overlaps the signal readout circuit 7 when viewed from the Z-axis direction, at least some of the dummy elements overlap the signal readout circuit 7. Say.

[Operation of photodetector]
The photodetector 1A configured as described above detects light as follows. First, when light enters the light receiving section 34 of the photodetector 30, heat is generated in the light absorption layer 76 that constitutes the optical resonance structure described above. At this time, the light receiving section 34 and the substrate 2A are thermally separated by the air gap S1. Further, the light receiving section 34, the first connection section 35 and the first beam section 37 are thermally separated by the first slit 31a. Further, the light receiving section 34, the first connection section 36 and the first beam section 38 are thermally separated by the first slit 31b. Therefore, the heat generated in the light absorption layer 76 is suppressed from escaping to the substrate 2A side via the first beam portions 37 and 38 and the first connection portions 35 and 36 . Furthermore, the light absorption layer 76 and the first wiring layers 71 and 72 are thermally separated by the separation layer 77 . Therefore, before the heat generated in the light absorption layer 76 is sufficiently transmitted to the first resistance layer 75 through the separation layer 77, the heat escapes through the first wiring layers 71 and 72 to the substrate 2A side. is suppressed.

Heat generated in the light absorption layer 76 is transferred to the first resistance layer 75 through the isolation layer 77 . This heat causes the temperature of the first resistance layer 75 to rise and the electrical resistance to fall. A signal due to this 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 . When a drive signal is input through the I/O pad 12, the shift registers 11a and 11c select the signals in the respective photodetector elements 30 by designating column and row addresses in the pixel section 3. read out. At this time, the reference element 40 of the reference section 4 also sends a signal due to the change in electrical resistance to the signal readout circuit 7 . When a drive signal is input through the I/O pad 12, the shift registers 11b and 11c specify the column and row addresses in the reference section 4 to select the signal 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. A readout circuit 9 amplifies, measures and holds the signal output by the correction circuit 8 . The I/O pads 12 sequentially output the signals amplified, measured and held by the readout circuit 9 . Then, the photodetector 1A detects light based on the difference between the signal from the photodetector 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 the corresponding plurality of photodetecting elements 30 is read. That is, one reference element 40 is used for compensation of a plurality of corresponding photodetection elements 30 . Therefore, the detection accuracy of one reference element 40 affects the detection accuracy of the plurality of photodetection elements 30 . Also, the number of times the signal is read out from the reference element 40 is greater than the number of times the signal is read out from the photodetector element 30 . Therefore, the reference element 40 is more susceptible to deterioration than the photodetector element 30 . For these reasons, it is essential to devise ways to ensure the compensation accuracy of the reference element.

[Action and effect]
As described above, in the photodetector 1A, the first dummy elements 50 are arranged along the outer edge of the first region 3a, and the second dummy elements 60 are arranged along the outer edge of the second region 4a. Therefore, the first film body 31 of the photodetector element 30 and the second film of the reference element 40 are more dense than in the case where the space is formed without the first dummy element 50 and the second dummy element 60 . The body 41 is placed in a uniform environment, and as a result, the detection accuracy of the photodetector 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 section 22A, the first dummy element 50 and the second dummy element 60 are electrically connected to the circuit section 22A. No circuit structure is required. Therefore, according to the photodetector 1A, detection accuracy can be ensured while suppressing complication of the structure.

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

Further, in the photodetector 1A, the first dummy element 50 is arranged along the outer edge of the first area 3a in the area between the first area 3a and the second area 4a on the surface 2a. An element 60 is arranged on the surface 2a in a region between the first region 3a and the second region 4a along the outer edge of the second region 4a. According to this configuration, in addition to the first dummy element 50 being arranged along the outer edge of the first region 3a, the first dummy element 50 is positioned between the first region 3a and the second region 4a. , and the second dummy element 60 is arranged along the outer edge of the second region 4a, and the second dummy element 60 is arranged in the region between the first region 3a and the second region 4a. It is Therefore, the first film body 31 of the photodetector element 30 and the second film body 41 of the reference element 40 are placed in a more uniform environment. Accuracy is further improved.

Further, 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, respectively. A plurality of them are arranged on the surface 2a along each of 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 photodetector element 30 are placed in a uniform environment. 30 detection accuracy is improved.

Further, in the photodetector 1A, the fourth film body 61 of the second dummy element 60 arranged 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, and arranged along the outer edge of the first region 3a. It has the same shape as the one 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 photodetector element 30 are placed in a more uniform environment. The detection accuracy of the element 30 is further improved.

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

In addition, 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. The stray light incident on the first film body 31 from is blocked by the first dummy element 50 . This improves the detection accuracy of the photodetector 30 .

[Method for manufacturing photodetector]
Next, a method for manufacturing the photodetector element 30 will be described with reference to FIGS. 17 to 26. FIG. In FIGS. 17 to 23 and 26, II, II-II, III-III, IV-IV, and VV in (b) are the II lines in (a), respectively. 4A and 4B are cross-sectional views taken along II-II line, III-III line, IV-IV line, and VV line; In FIGS. 24 and 25, a diagram such as 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. Then, as shown in FIG. The material of the sacrificial layer 39 is, for example, polyimide. Subsequently, as shown in FIG. 19, through holes 39a and 39b are formed in the sacrificial layer 39 by partially removing the sacrificial layer 39 by etching. The through holes 39a and 39b are formed on the first electrode pads 25 and 26 corresponding to the through holes 27a and 27b, respectively. The surfaces of the first electrode pads 25 and 26 opposite to the substrate 2A are exposed through the through holes 39a and 39b. The inner surfaces of the through holes 39a and 39b are, for example, truncated cone-shaped tapered surfaces. The inner surfaces of the through holes 39a and 39b widen from the first electrode pads 25 and 26 toward the side opposite to the substrate 2A. 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 such that the inner surfaces of the through holes 39a and 39b are tapered, for example, in the shape of a truncated cone. Subsequently, a portion of the insulating layer 74 is removed by etching to expose the surface of each of the first electrode pads 25 and 26 opposite to the substrate 2A.

Subsequently, as shown in FIG. 21, the first electrode posts 32 are formed on the insulating layer 74 in the through holes 39a, and the first electrode posts 33 are formed on the insulating layer 74 in the through holes 39b. Each of the first electrode posts 32 and 33 is formed by vapor deposition, for example. Then, 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. Then, the first wiring layers 71 and 72 are processed into the shape described above by dry etching, for example.

Subsequently, as shown in FIG. 23, the light receiving portion 34, the first beam portions 37 and 38, and the first connection portions 35 and 36 are formed so as to cover the first wiring layers 71 and 72 from the opposite side of the substrate 2A. An insulating layer 73 is formed over the . The insulating layer 73 is processed into the shape described above by etching. Subsequently, as shown in FIG. 24, in the light receiving section 34, a first resistance layer 75 is formed so as to cover the insulating layer 73 from the opposite side of the substrate 2A. A first resistive 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, , an isolation layer 77 is formed on the insulating layer 73 .

Subsequently, as shown in FIG. 25, in the light receiving section 34, the light absorption layer 76 is formed on the separation layer 77, and the through holes 31c are formed. The light absorbing layer 76 is processed into the shape described above by etching. The through holes 31c are formed at the positions described above by etching. Subsequently, as shown in FIG. 26, the first slits 31a and 31b are formed at the positions described above by, for example, dry etching, and dry etching is advanced from the first slits 31a and 31b and the through hole 31c to form the sacrificial layer. By removing 39, a gap S1 is formed.

The method for manufacturing the reference element 40 differs from the method for manufacturing the photodetector element 30 described above in that the light absorption layer 76 is not formed. In addition, the manufacturing method of the first dummy element 50 and the second dummy element 60 has the advantage that the light absorbing layer 76 is not formed and that the sacrificial layer 39 and the insulating layer 84 are partially exposed by removing. It is different from the above-described method of manufacturing the photodetector element 30 in that it is not the surface of the electrode pad but the surface of the insulating layer 27 . 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 in parallel with the substrate 2A on which the layer 27 is provided.

In the method for manufacturing the photodetector element 30, when dry etching is performed, for example, in the vicinity of the center of the first region 3a and the edge of the first region 3a, the etchant (etching gas) does not flow due to the loading effect or the like. The density distribution may become uneven, 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 become uneven. As a result, the detection accuracy of the manufactured photodetector element 30 may deteriorate. Therefore, since the photodetector 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 , the unevenness of the density of the etching pattern is suppressed. As a result, the density distribution of the etchant is prevented from becoming uneven in the vicinity of the center of the first region 3a and the edge of the first region 3a due to the loading effect. Therefore, 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 are prevented from becoming uneven. That is, the manufacturing process of the photodetector 30 is stabilized. Therefore, detection accuracy by the photodetector 30 is ensured.

Such an effect is similarly produced in the manufacture of the reference element 40 as well. 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 central region of the second region 4a and the second region 4a are manufactured at the same time. Non-uniformity of the etching pattern at the edges is suppressed. As a result, the density distribution of the etchant is prevented from becoming uneven in the vicinity of the center of the second region 4a and the edge of the second region 4a due to the loading effect. Therefore, the shapes of 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 becoming uneven. That is, the manufacturing process of the reference element 40 is stabilized. Therefore, detection accuracy by the reference element 40 is ensured.

In addition, 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 in some cases. Therefore, 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 precision. That is, the effect of stabilizing the manufacturing process as described above is particularly effective for the reference element 40 . In addition, when viewed from the Z-axis direction, 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 photodetector element 30. The effect of suppressing non-uniformity in the sparse and dense state of the etching pattern becomes even more remarkable.

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

An example in which the third region 5a and the fourth region 6a respectively surround the first region 3a and the second region 4a has been shown, but as shown in FIG. It may surround each of the first region 3a and the second region 4a. That is, only the second dummy element 60 is formed 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, respectively, so as to surround the first region 3a and the second region 4a. A plurality of them may be arranged.

Also, as shown in FIG. 28, the third region 5a and the fourth region 6a may surround the entire outer edge of the first region 3a and the second region 4a. That is, the first dummy element 50 and the second dummy element 60 are formed 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 of them 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 to form a rectangular loop. And the 1st area|region 3a and the 2nd area|region 4a are located inside the said rectangular cyclic|annular form. 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 arranged 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 edge of the first region 3a and the second region 4a, the second film body 41 of the reference element 40 and the first The film body 31 is placed in a uniform environment, and as a result, the detection accuracy of the reference element 40 and the detection accuracy of the photodetector 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 formed by the first region 3a and the second region 4a is the region extending from the first region 3a to the second region 4a. be. When the first region 3a and the second region 4a are separated from each other, the sum of the first region 3a, the second region 4a, and the region between the first region 3a and the second region 4a is It is an area extending from the first area 3a to the second area 4a.

Alternatively, 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 elements 60 are arranged 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 have been

Also, as shown in FIG. 30, the first region 3a may not be surrounded by any region. That is, the first region 3a does not have to be surrounded by any dummy elements. The fourth region 6a surrounds only the second region 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 portions of the second region 4a other than the side portions on the side of the first region 3a. In other words, 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 side of the first region 3a. 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 side opposite to the first region 3a with respect to the second region 4a. That is, the second dummy element 60 may be 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. 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. 33, the fourth region 6a is formed only on the side opposite to the first region 3a with respect to the second region 4a, and the third region 5a is formed only on the side opposite to the first region 3a. 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. It may be arranged along the outer edge of the first region 3a only in the region opposite to the second region 4a with respect to the 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.

Moreover, 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 region 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 multiple 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.

Further, as shown in FIG. 35, even if the first region 3a is not surrounded by any region, the fourth region 6a is formed by dividing a plurality of regions along each side of the second region 4a. may contain.

Further, 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 A plurality of rectangular regions along each side of the region 3a may be included, and the fourth region 6a may include a plurality of regions along each side of 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.

Further, as shown in FIG. 37, even in the case where the fourth region 6a surrounds only the side portion of the second region 4a other than the side portion on the side of the first region 3a, the fourth region 6a is the second region. It may include multiple regions along each side of 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.

Although the first dummy elements 50 surround the first regions 3a in four columns and the second dummy elements 60 surround the second regions 4a in four columns, the first dummy elements 50 cover at least the first regions 3a. It suffices that the second dummy element 60 surrounds the second region 4a in at least one row. Further, even when the first dummy element 50 and the second dummy element 60 surround the entire outer edge 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 suffices that one row surrounds the entire outer edges of the first region 3a and the second region 4a.

In addition, although an example in which the photodetector elements 30 are arranged in, for example, about 64 columns x 64 rows to 128 columns x 128 rows, the photodetector elements 30 are arranged, for example, in 32 columns x 32 rows to 480 columns x It suffices if they are arranged so as to have about 640 lines. In addition, although an example in which the reference elements 40 are arranged in, for example, about 16 columns x 64 rows to 16 columns x 128 rows, the reference elements 40 are arranged, for example, in 1 column x 32 rows to 24 columns x 640 rows. It suffices if they are arranged so as to be about the same.

A first dummy element 50 is arranged along the outer edge of the first region 3a in a region between the first region 3a and the second region 4a on the surface 2a of the substrate 2A, and a second dummy device 60 is arranged in the region between the first region 3a and the second region 4a. Although an example in which they are arranged along the outer edge of the second region 4a has been shown, the first dummy element 50 is located in the region between the first region 3a and the second region 4a on the surface 2a of the substrate 2A. It may be arranged along the outer edge of the region 3a, or the second dummy element 60 may be arranged along the outer edge of the second region 4a. That is, in the region between the first region 3a and the second region 4a on the surface 2a of the substrate 2A, at least one of the first dummy element 50 and the second dummy element 60 is located on the outer edge of the first region 3a and the second dummy device. It suffices if they are arranged along at least one of the outer edges of the two regions 4a.

Moreover, 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 arranged along the outer edge of the first region 3a, and the first dummy element 50 may be arranged along the outer edge of the second region 4a. Also, 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 Further, instead of the first dummy element 50 or the second dummy element 60, dummy elements other than the first dummy element 50 and the second dummy element 60 may be arranged.

In addition, although the example in which the first region 3a and the second region 4a have a rectangular shape has been shown, the first region 3a and the second region 4a may have, for example, a polygonal shape other than a rectangular shape or a circular shape. good too. That is, the pixel section 3 and the reference section 4 may have, for example, a polygonal shape other than a rectangular shape or a circular shape when viewed from the Z-axis direction. Further, although an example in which the third region 5a and the fourth region 6a have a rectangular annular shape has been shown, the outer edges of the third region 5a and the fourth region 6a may have, for example, a polygonal shape other than a rectangular shape or a circular shape. It's okay. In other words, the outer edges of the first dummy portion 5 and the second dummy portion 6 may have, for example, a polygonal shape other than a rectangular shape or a circular shape when viewed from the Z-axis direction.

Also, although the first film body 31, the second film body 41, the third film body 51, and the fourth film body 61 each have a rectangular shape when viewed from the Z-axis direction, an example has been shown. , the first film body 31, the second film body 41, the third film body 51, and the fourth film body 61 each exhibit, for example, a polygonal shape other than a rectangular shape when viewed from the Z-axis direction. good too.

Further, an example has been shown in which some of the first dummy elements 50 and some of the second dummy elements 60 overlap the signal readout circuit 7 when viewed from the Z-axis direction. 50 and the second dummy element 60 do not have to overlap the signal readout circuit 7 when viewed from the Z-axis direction.

Moreover, at least one of the first dummy element 50 and the second dummy element 60 is provided in a region other than the first region 3a and the second region 4a, and only one of the outer edge of the first region 3a and the outer edge of the second region 4a. may be arranged along the That is, at least one of the first dummy element 50 and the second dummy element 60 is placed in a region other than the first region 3a and the second region 4a along at least one of the outer edge of the first region 3a and the outer edge of the second region 4a. It is sufficient if the

A plurality of first dummy elements 50 are arranged in a region other than the first region 3a and the second region 4a of the surface 2a of the substrate 2A so as to be aligned in a direction intersecting the outer edge of the first region 3a. An example has been shown in which a plurality of dummy elements 60 are arranged in a region other than the first region 3a and the second region 4a of the surface 2a of the substrate 2A so as to be aligned in the direction intersecting the outer edge of the second region 4a. , but not limited to. In 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 them may be arranged in regions other than the first region 3a and the second region 4a. In other words, at least one of the first dummy element 50 and the second dummy element 60 is aligned 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. A plurality of them may be arranged in regions other than the first region 3a and the second region 4a.

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

[Second embodiment]
As shown in FIG. 38, the photodetector 1B of the second embodiment is different from the first embodiment in that the pixel portion is composed of one photodetector element 30 and the reference portion is composed of one reference element 40. It is mainly different from the photodetector 1A of the embodiment.

The photodetector 1B includes a substrate 2B having a surface 2b, a photodetector element 30, a reference element 40, a first dummy section 5, and a second dummy section 6. As shown in FIG. The thickness of the substrate 2B is, for example, about several hundred μm. The photodetector element 30, the reference element 40, the first dummy section 5, and the second dummy section 6 are formed on the surface 2b of the substrate 2B.

When viewed from the Z-axis direction (the thickness direction of the substrate 2B), the photodetector element 30 and the reference element 40 are arranged side by side in the X-axis direction (the direction orthogonal to the Z-axis) parallel to the surface 2b. ing. The photodetector 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 element 30. FIG. The first dummy section 5 surrounds the photodetector element 30 and the reference element 40 together with the second dummy section 6 . The first dummy section 5 and the second dummy section 6 are adjacent to each other.

A circuit portion 22B and a plurality of I/O pads 12 are provided on the substrate 2B. The circuit section 22B is provided in layers 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 readout circuit (signal readout 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 electrically connecting each component. wiring (not shown).

The analog readout circuit 13 is provided in a rectangular annular area when viewed from the Z-axis direction. The analog readout circuit 13 surrounds the photodetector 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 of the analog readout circuit 13 in the X-axis direction (direction orthogonal to the Z-axis) parallel to the surface 2b. The digital interface 16 is arranged side by side 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 side by side with the timing generator 17, the analog readout circuit 13, the DSP 15, and the digital interface 16 in the Y-axis direction. A plurality of I/O pads 12 are arranged along the outer edge of 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 to form a rectangular loop. And the 1st area|region 3a and the 2nd area|region 4a are located inside the said rectangular cyclic|annular form.

The outer edge of the photodetector 30 overlaps the outer edge of the first region 3a when viewed from the Z-axis direction. The outer edge of the reference element 40 overlaps 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 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 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 section 6 is composed of 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 photodetector elements 30 and the reference elements 40 in a plurality of rows (here, four rows). are placed. In this manner, the first dummy element 50 and the second dummy element 60 are formed 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. 2a. That is, a plurality of first dummy elements 50 and second dummy elements 60 are arranged on the surface 2a along the outer edges of the photodetector element 30 and the reference element 40 so as to surround the photodetector element 30 and the reference element 40, respectively.

The first dummy element 50 and the second dummy element 60 overlap the circuit section 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.

The photodetector 1B configured as described above detects light as follows. First, heat generated in the light absorption layer 76 is transmitted to the first resistance layer 75 through the separation layer 77, as in the photodetector 1A. This heat causes the temperature of the first resistance layer 75 to rise and the electrical resistance to fall. A signal resulting from this 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 . At this time, a signal due to a change in electrical resistance is also sent from the reference element 40 to the analog reading circuit 13 . The analog readout circuit 13 amplifies and corrects the signal due to the change in electrical resistance of the photodetector element 30 and the signal due to the change in electrical resistance of the reference element 40 and outputs them. The AD converter 14 converts the signal amplified and corrected by the analog readout circuit 13 into a digital signal. The DSP 15 outputs the digital signal converted by the AD converter 14 to the digital interface 16 after performing predetermined signal processing. The timing generator 17 outputs a drive timing signal to the DSP 15 when a drive signal is input via the I/O pad 12 . The digital interface 16 outputs the signal output by 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 . Then, the photodetector 1B detects light based on the difference between the signal from the photodetector element 30 and the signal from the reference element 40 .

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

When the pixel portion is composed of one photodetector element 30 and the reference portion is composed of 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, the dry etching conditions need to be optimized. In the photodetector 1B, the first dummy element 50 and the second dummy element 60 are arranged 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. 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 when 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 edge of the first region 3a and the second region 4a. That is, only the first dummy elements 50 are arranged 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 have been Also, instead of the third region 5a, only the fourth region 6a may surround the entire outer edge 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 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 of them may be arranged on the surface 2a of the substrate 2A.

In addition, as shown in FIG. 41, the third region 5a is formed on both sides of the first region 3a in the Y-axis direction and on the opposite side of the first region 3a to the second region 4a. It may extend along the Y-axis direction and the X-axis direction. That is, the first dummy elements 50 are arranged on both sides of the first region 3a in the Y-axis direction and on the opposite side of the first region 3a to the second region 4a in the Y-axis direction and the X-axis direction, respectively. may be arranged in plurality along the Similarly, the fourth region 6a is formed on both sides of the second region 4a in the Y-axis direction and on the opposite side of the second region 4a to the first region 3a in the Y-axis direction and the X-axis direction, respectively. may extend along the That is, the second dummy elements 60 are arranged on both sides of the second region 4a in the Y-axis direction and on the side of the second region 4a opposite to the first region 3a in the Y-axis direction and the X-axis direction, respectively. may be arranged in plurality along the

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

Also, as shown in FIG. 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. In other words, each of the first dummy element 50 and the second dummy element 60 surrounds the first region 3a and the second region 4a, respectively, along the outer edge of the first region 3a and the outer edge of the second region 4a. are arranged on the surface 2a.

Alternatively, as shown in FIG. 43, only the third region 5a may surround the first region 3a and the second region 4a. That is, only the first dummy elements 50 are arranged 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 the first region 3a and the second region 4a, respectively. may be Also, instead of the third region 5a, only the fourth region 6a may surround the first region 3a and the second region 4a. In other words, instead of the first dummy element 50, only the second dummy element 60 surrounds the first region 3a and the second region 4a, respectively. A plurality may be arranged on the surface 2a along the .

In addition, as shown in FIG. 44, the third region 5a is arranged on both sides of the first region 3a in the Y-axis direction and on both sides of the first region 3a in the X-axis direction. and the X-axis direction. That is, the first dummy elements 50 are arranged along the Y-axis direction and the X-axis direction on both sides of the first region 3a in the Y-axis direction and on both sides of the first region 3a in the X-axis direction. 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 of the second region 4a in the Y-axis direction and on both sides of the second region 4a in the X-axis direction. May be extended. That is, the second dummy elements 60 are arranged along the Y-axis direction and the X-axis direction on both sides of the second region 4a in the Y-axis direction and on both sides of the second region 4a in the X-axis direction. A plurality of them may be arranged.

Further, instead of the fourth region 6a, the third region 5a is arranged on both sides of the second region 4a in the Y-axis direction and on both sides of the second region 4a in the X-axis direction, respectively. and the X-axis direction. That is, instead of the second dummy elements 60, the first dummy elements 50 are arranged on both sides of the second region 4a in the Y-axis direction and on both sides of the second region 4a in the X-axis direction. A plurality of them may be arranged along the axial direction and the X-axis direction. Similarly, instead of the third region 5a, the fourth region 6a is arranged on both sides of the first region 3a in the Y-axis direction and on both sides of the first region 3a in the X-axis direction, respectively. direction and the X-axis direction. That is, instead of the first dummy elements 50, the second dummy elements 60 are arranged on both sides of the first region 3a in the Y-axis direction and on both sides of the first region 3a in the X-axis direction, respectively. A plurality of them may be arranged along the axial direction and the X-axis direction.

Moreover, although the first dummy element 50 and the second dummy element 60 overlap the analog readout circuit 13 when viewed from the Z-axis direction, the first dummy element 50 and the second dummy element 60 , and the analog readout circuit 13 when viewed in the Z-axis direction.

1A, 1B... photodetector, 2A, 2B... substrate, 2a, 2b... surface, 3a... first area, 4a... second area, 5a... third area, 6a... fourth area, 7... signal readout circuit, DESCRIPTION OF SYMBOLS 13... Analog read-out circuit (signal read-out circuit), 22A, 22B... Circuit part, 30... Photodetection element, 31... First film body, 40... Reference element, 41... Second film body, 50... First dummy element, 51... Third film body, 60... Second dummy element, 61... Fourth film body, S1, S2, S3, S4... Gaps.

Claims (10)

a substrate having a surface;
a first membrane disposed on the surface with a gap therebetween; and a first membrane disposed between the substrate and the first membrane to support the first membrane on the surface with the gap therebetween. a photodetector having a pair of first electrode posts ;
a second membrane disposed on the surface with a gap therebetween; and a second membrane disposed between the substrate and the second membrane to support the second membrane on the surface with the gap therebetween. a reference element having a pair of second electrode posts ;
and a pair of electrode posts arranged between the substrate and the membrane and supporting the membrane on the surface with the gap therebetween. a dummy element;
a circuit unit provided on the substrate and electrically connected to the photodetector element and the reference element;
The photodetector element is an element for detecting light based on a temperature change due to light reception, and is arranged in a first region of the surface,
The reference element is an element for compensating temperature changes due to factors other than the light reception in the photodetector element, and is arranged in a second region of the surface,
the dummy element is arranged in a region other than the first region and the second region of the surface along at least one of an outer edge of the first region and an outer edge of the second region;
The photodetector, wherein the dummy element is electrically insulated from the circuit section. A plurality of the dummy elements are arranged in the area of the surface other than the first area and the second area so as to be aligned in a direction intersecting at least one of the outer edge of the first area and the outer edge of the second area. 2. The photodetector of claim 1, wherein the photodetector is The dummy element is further arranged in a region between the first region and the second region of the surface along at least one of an outer edge of the first region and an outer edge of the second region. 3. A photodetector according to claim 1 or 2. The dummy element is arranged along the outer edge of the second region,
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 photodetector according to any one of claims 1 to 3. The dummy element is arranged along the outer edge of the first region,
The film of the dummy element arranged along the outer edge of the first region has the same shape as the first film of the photodetector when viewed from the thickness direction of the substrate. A photodetector according to any one of claims 1 to 4, comprising: The light according to any one of claims 1 to 5, wherein a plurality of said dummy elements are arranged on said surface along the outer edge of said second region so as to surround said second region in at least one row. Detector. A plurality of said dummy elements are arranged on said surface along outer edges of said first region and said second region so as to surround said first region and said second region in at least one row. 7. The photodetector according to any one of 6. A plurality of the dummy elements are arranged on the surface along the outer edge of the first area and the outer edge of the second area so as to surround each of the first area and the second area in at least one row. A photodetector according to any one of claims 1 to 6, comprising: The film of the dummy element arranged along the outer edge of the second region has the same shape as the second film of the reference element when viewed from the thickness direction of the substrate. ,
The film of the dummy element arranged along the outer edge of the first region has the same shape as the first film of the photodetector when viewed from the thickness direction of the substrate. A photodetector according to any one of claims 6 to 8, wherein The circuit section includes a signal readout circuit,
10. The photodetector according to claim 1, wherein said dummy element overlaps said signal readout circuit when viewed from the thickness direction of said substrate.

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