Fabry-perot interference filter

Abstract

To provide a Fabry-Perot interference filter capable of obtaining reliability.SOLUTION: A Fabry-Perot interference filter includes a first reflective film 50, a second reflective film 60, a first layer 10 including a first electrode 19 and supporting the first reflective film 50, and a second layer 20 laminated on the first layer 10. The second layer 20 includes: a second substrate 21; a second electrode 22 arranged on a surface 21b of the second substrate 21; a third electrode 24 arranged on a surface 21a of the second substrate 21; and a penetration electrode 26 electrically connecting the second electrode 22 with the third electrode 24 on the second substrate 21. The first layer 10 includes an electrode part 16 being the first electrode 19, a support part 17 connected to the second layer 20, and an elastic deformation part 18 connecting the electrode part 16 and the support part 17. When viewed from a Z axis direction, the penetration electrode 26 is positioned in an area without overlapping with the elastic-deformation part 18 in an areas between the electrode part 16 and the support part 17.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a Fabry-Perot interference filter. [Background technology]

[0002] SUMMARY OF THE DISCLOSURE A Fabry-Perot interference filter is known that includes a first substrate, a second substrate stacked on the first substrate, a first reflective film formed on a first surface of the first substrate facing the second substrate, a second reflective film formed on a second surface of the second substrate facing the first substrate so as to face the first reflective film, a first electrode formed on the first surface of the first substrate, a second electrode formed on the second surface of the second substrate facing the first electrode, a first pad and a second pad formed on a third surface of the second substrate opposite the first substrate, a first through electrode provided on the second substrate and electrically connecting the first electrode and the first pad, and a second through electrode provided on the second substrate and electrically connecting the second electrode and the second pad, in which a portion of the first substrate that supports the first reflective film is configured as a movable portion for changing the distance between the first reflective film and the second reflective film (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-83850 A Summary of the Invention [Problem to be solved by the invention]

[0004] In general, in a film-like electrode to which a through electrode is connected, the film thickness is likely to change at the connection point of the through electrode. Therefore, in the above-mentioned Fabry-Perot interference filter, a configuration in which the first through electrode and the second through electrode are arranged outside the elastic deformation part of the first substrate supporting the movable part may be adopted. However, when such a configuration is adopted, the bonding area between the first substrate and the second substrate is reduced, and the reliability of the Fabry-Perot interference filter may be reduced.

[0005] An object of the present invention is to provide a Fabry-Perot interference filter capable of ensuring reliability. [Means for solving the problem]

[0006] The Fabry-Perot interference filter of the present invention is provided with: [1] "a first reflective film; a second reflective film facing the first reflective film via a space in a light transmitting region; a first layer including a first electrode and supporting the first reflective film; and a second layer stacked on the first layer on one side in a first direction in which the first reflective film and the second reflective film face each other, the second layer including a substrate having a first surface on the first layer side and a second surface opposite to the first layer, a second electrode disposed on the first surface and facing the first electrode via a space in the first direction, and a third electrode disposed on the second surface, the second electrode being disposed on the substrate and supporting the first electrode and the second electrode. a through electrode electrically connecting the first layer to a third electrode, the first layer being a movable layer configured as a movable part whose portion overlapping the light transmitting region is movable in the first direction, the first layer being provided on the movable part and including an electrode part on which the first electrode is provided or which is the first electrode, a support part which is joined to the second layer, and an elastic deformation part which connects the electrode part and the support part, the end part of the through electrode on the second electrode side being located in a region between the electrode part and the support part which does not overlap with the elastic deformation part when viewed from the first direction.

[0007] In the Fabry-Perot interference filter described in [1] above, the through electrode electrically connects the second electrode and the third electrode in the substrate of the second layer, and when viewed from the first direction in which the first reflection film and the second reflection film face each other, the end of the through electrode on the second electrode side is located in a region between the electrode part and the support part that does not overlap with the elastic deformation part. This ensures flatness of at least the region of the second electrode facing the first electrode, so that a desired electrostatic force can be reliably generated between the first electrode and the second electrode. In addition, even if the end of the through electrode on the second electrode side is formed in a convex shape, physical interference between the end of the through electrode on the second electrode side and the elastic deformation part can be suppressed. In addition, the bonding area between the support part of the first layer and the second layer can be sufficiently ensured, so that the stability of the bonding between the first layer and the second layer can be improved. As a result, the Fabry-Perot interference filter described in [1] above can ensure reliability.

[0008] The Fabry-Perot interference filter of the present invention may be [2] "the Fabry-Perot interference filter according to the above [1], further comprising a third layer that is laminated on the first layer on the other side in the first direction and supports the second reflective film." According to the Fabry-Perot interference filter according to [2], the movable part of the first layer can be protected from both sides by the second layer and the third layer.

[0009] The Fabry-Perot interference filter of the present invention may be [3] "the Fabry-Perot interference filter according to the above [1] or [2], in which the elastic deformation parts are a plurality of elastic deformation parts connecting the electrode part and the support part, and the end part of the through electrode is located in a region between a pair of adjacent elastic deformation parts among the plurality of elastic deformation parts when viewed from the first direction." According to the Fabry-Perot interference filter according to [3], the end part of the through electrode can be arranged in a well-balanced manner with respect to the electrode part, the support part, and the plurality of elastic deformation parts of the first layer. In addition, since the movable part is supported by the plurality of elastic deformation parts, the parallelism of the first reflection film with respect to the second reflection film can be more reliably ensured.

[0010] The Fabry-Perot interference filter of the present invention may be [4] "the Fabry-Perot interference filter according to the above [3], in which the through electrodes are a plurality of through electrodes electrically connecting the second electrode and the third electrode, and the plurality of ends of the through electrodes on the second electrode side are located in the region between the pair of elastic deformation parts when viewed from the first direction." According to the Fabry-Perot interference filter according to [4], even when a plurality of through electrodes are provided on the substrate of the second layer, the ends of the plurality of through electrodes can be arranged in a well-balanced manner with respect to the electrode part, the support part, and the plurality of elastic deformation parts of the first layer. In addition, since the second electrode and the third electrode are electrically connected by a plurality of through electrodes, the wiring resistance can be reduced, and the potential difference between the second electrode and the third electrode can be reduced.

[0011] The Fabry-Perot interference filter of the present invention may be [5] "the Fabry-Perot interference filter according to any one of the above [1] to [4], wherein the through electrode is located in the region between the electrode portion and the support portion that does not overlap with the elastic deformation portion when viewed from the first direction." According to the Fabry-Perot interference filter described in [5], the configuration of the through electrode can be simplified, for example, by forming the through electrode linearly along the first direction in which the first reflection film and the second reflection film face each other.

[0012] The Fabry-Perot interference filter of the present invention may be [6] "the Fabry-Perot interference filter according to any one of the above [1] to [5], in which the elastic deformation portion has electrical conductivity." When viewed from the first direction, if the end of the through electrode on the second electrode side overlaps with the elastic deformation portion having electrical conductivity, the magnitude of the electrostatic force generated between the end and the elastic deformation portion may vary when the shape of the end varies, and the parallelism of the first reflection film to the second reflection film may not be ensured. According to the Fabry-Perot interference filter according to [6], when viewed from the first direction, the end of the through electrode on the second electrode side does not overlap with the elastic deformation portion having electrical conductivity, so that the parallelism of the first reflection film to the second reflection film can be ensured even when the shape of the end of the through electrode on the second electrode side varies. Effect of the Invention

[0013] According to the present invention, it is possible to provide a Fabry-Perot interference filter capable of ensuring reliability. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of an embodiment of a Fabry-Perot interference filter. [Diagram 2] FIG. 2 is an exploded perspective view of the Fabry-Perot interference filter shown in FIG. [Diagram 3] FIG. 2 is an exploded perspective view of the Fabry-Perot interference filter shown in FIG. [Figure 4] 2 is a longitudinal sectional view of the Fabry-Perot interference filter shown in FIG. 1. [Diagram 5] 2A and 2B are top and bottom views of the first layer shown in FIG. 1. [Figure 6] 2A and 2B are top and bottom views of the second layer shown in FIG. 1. [Figure 7] 2A and 2B are top and bottom views of the third layer shown in FIG. 1. [Figure 8] 2 is a longitudinal cross-sectional view of a portion of the absorbent membrane shown in FIG. 1. [Figure 9]2A and 2B are a plan view and a cross-sectional view of the Fabry-Perot interference filter shown in FIG. [Figure 10] FIG. 11 is a longitudinal sectional view of a modified Fabry-Perot interference filter. [Figure 11] FIG. 13 is a plan view of a portion of a modified Fabry-Perot interference filter. [Figure 12] FIG. 13 is a plan view of a portion of a modified Fabry-Perot interference filter. [Figure 13] 13 is a cross-sectional view of a portion of the Fabry-Perot interference filter taken along line XIII-XIII shown in FIG. 12. [Figure 14] FIG. 11 is a longitudinal sectional view of a portion of an absorbing film of a modified Fabry-Perot interference filter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0016] As shown in FIG. 1, FIG. 2, FIG. 3, and FIG. 4, the Fabry-Perot interference filter 1 includes a first layer 10, a second layer 20, a third layer 30, a first reflection film 50, a second reflection film 60, and an absorption film 70. The first reflection film 50 and the second reflection film 60 face each other through a space. In the following description, the direction in which the first reflection film 50 and the second reflection film 60 face each other (first direction) is referred to as the "Z-axis direction", one direction perpendicular to the Z-axis direction (second direction intersecting with the first direction) is referred to as the "X-axis direction", and a direction perpendicular to both the Z-axis direction and the X-axis direction (third direction intersecting with both the first direction and the second direction) is referred to as the "Y-axis direction". Note that when "one side" is simply referred to, it means one side in the Z-axis direction, and when "the other side" is simply referred to, it means the other side in the Z-axis direction. Also, when "thickness" is simply referred to, it means the thickness in the Z-axis direction.

[0017] In the Fabry-Perot interference filter 1, the area overlapping both the first reflection film 50 and the second reflection film 60 when viewed from the Z-axis direction functions as the light-transmitting area 1a. The light-transmitting area 1a is an area in which the first reflection film 50 and the second reflection film 60 function as mirrors and transmit light according to the distance between the first reflection film 50 and the second reflection film 60. As an example, the light-transmitting area 1a is a cylindrical area with a straight line L parallel to the Z-axis direction as its center line. In the following description, the radial direction of a circle centered on the straight line L when viewed from the Z-axis direction is simply referred to as the "radial direction", and the circumferential direction of the circle is simply referred to as the "circumferential direction". Note that the vertical cross-sectional view of FIG. 4 is a schematic diagram of the Fabry-Perot interference filter 1, and the aspect ratio in FIG. 4 does not match the actual one.

[0018] 4 and 5, the first layer 10 includes a first substrate 11, a semiconductor layer 12, and a metal pad 13. Note that (a) of Fig. 5 is a plan view of the first layer 10, and (b) of Fig. 5 is a bottom view of the first layer 10.

[0019] The first substrate 11 includes a light-transmitting member 14 and a supporting member 15. The light-transmitting member 14 and the supporting member 15 are each made of a light-transmitting material such as glass or silicon. As an example, the light-transmitting member 14 and the supporting member 15 are formed separately by etching a glass substrate bonded to a silicon substrate that will become the semiconductor layer 12. The glass substrate and the silicon substrate are bonded together by airtight bonding such as room temperature bonding, plasma activated bonding, and anodic bonding. In the Fabry-Perot interference filter 1, the light-transmitting member 14 and the supporting member 15 made of the same light-transmitting material constitute the first substrate 11. However, as long as at least the light-transmitting member 14 is made of a light-transmitting material, the light-transmitting member 14 and the supporting member 15 may be made of different materials.

[0020] The light transmitting member 14 constitutes a part of the light transmitting region 1a. When viewed from the Z-axis direction, the outer edge of the light transmitting member 14 is located outside the outer edge of the light transmitting region 1a. As an example, the light transmitting member 14 is formed in a circular plate shape with the straight line L as the center line. The outer diameter of the light transmitting member 14 is, for example, about 4 to 6 mm. The thickness of the light transmitting member 14 is, for example, about 0.2 to 0.5 mm.

[0021] The support member 15 surrounds the light transmitting member 14 when viewed from the Z-axis direction. A space is formed between the light transmitting member 14 and the support member 15. The thickness of the support member 15 is approximately equal to the thickness of the light transmitting member 14. As an example, the support member 15 is formed in a rectangular frame shape so as to have a pair of side surfaces perpendicular to the X-axis direction and a pair of side surfaces perpendicular to the Y-axis direction. The width of the support member 15 in each of the X-axis direction and the Y-axis direction is, for example, about 11 mm. The thickness of the support member 15 is, for example, about 0.2 to 0.5 mm. The width of the space between the light transmitting member 14 and the support member 15 is, for example, about 0.5 to 1.5 mm.

[0022] The semiconductor layer 12 includes an electrode portion 16, a support portion 17, and a plurality of elastic deformation portions 18. The electrode portion 16, the support portion 17, and the plurality of elastic deformation portions 18 are conductive. The material of each of the electrode portion 16, the support portion 17, and the plurality of elastic deformation portions 18 is, for example, a semiconductor material such as p-type silicon having a low resistance (1 Ωcm or less). As an example, the electrode portion 16, the support portion 17, and the plurality of elastic deformation portions 18 are integrally formed by etching a silicon substrate bonded to a glass substrate that becomes the first substrate 11.

[0023] The electrode portion 16 surrounds the light transmitting region 1a when viewed from the Z-axis direction. The electrode portion 16 extends along the outer edge of the light transmitting member 14 when viewed from the Z-axis direction, and is joined to the surface 14a on one side of the light transmitting member 14. When viewed from the Z-axis direction, the outer edge of the electrode portion 16 is located outside the outer edge of the light transmitting member 14. When viewed from the Z-axis direction, the inner edge of the electrode portion 16 is located inside the outer edge of the light transmitting member 14 and approximately coincides with the outer edge of the light transmitting region 1a. As an example, the electrode portion 16 is formed in a circular frame shape with the straight line L as the center line. The inner diameter of the electrode portion 16 is, for example, about 3 to 5 mm. The outer diameter of the electrode portion 16 is, for example, about 4 to 6 mm. The thickness of the electrode portion 16 is, for example, about 30 μm. In the Fabry-Perot interference filter 1, the electrode portion 16 functions as a first electrode 19. That is, the first layer 10 includes the first electrode 19.

[0024] The support 17 surrounds the electrode 16 when viewed from the Z-axis direction. A space is formed between the electrode 16 and the support 17. The support 17 is joined to the surface 15a on one side of the support member 15. In the Fabry-Perot interference filter 1, the outer edge of the support 17 approximately coincides with the outer edge of the support member 15 when viewed from the Z-axis direction. The inner edge of the support 17 is located inside the inner edge of the support member 15 when viewed from the Z-axis direction. As an example, the support 17 is formed in a rectangular frame shape so as to have a pair of side surfaces perpendicular to the X-axis direction and a pair of side surfaces perpendicular to the Y-axis direction. The width of the support 17 in each of the X-axis direction and the Y-axis direction is, for example, about 11 mm. The thickness of the support 17 is, for example, about 34 μm. The width of the space between the electrode 16 and the support 17 is, for example, about 0.5 to 1.5 mm.

[0025] The multiple elastic deformation parts 18 are located between the electrode part 16 and the support part 17, and surround the electrode part 16 when viewed from the Z-axis direction. A space is formed between a pair of adjacent elastic deformation parts 18. Each elastic deformation part 18 connects the electrode part 16 and the support part 17. That is, one end of each elastic deformation part 18 is connected to the electrode part 16, and the other end of each elastic deformation part 18 is connected to the support part 17. As an example, the multiple elastic deformation parts 18 are arranged in the circumferential direction at equal angular intervals. As an example, each elastic deformation part 18 is formed in a rectangular plate shape so as to extend in the radial direction. In the Fabry-Perot interference filter 1, the multiple elastic deformation parts 18 are a pair of elastic deformation parts 18 located on both sides of the electrode part 16 in the X-axis direction, and a pair of elastic deformation parts 18 located on both sides of the electrode part 16 in the Y-axis direction. The width of each elastic deformation part 18 in the radial direction is, for example, about 0.5 to 1.5 mm. The width of each of the elastic deformation portions 18 in the direction perpendicular to the radial direction is, for example, about 50 μm to 1 mm, and the thickness of each of the elastic deformation portions 18 is, for example, about 30 μm.

[0026] The thickness of each elastic deformation portion 18 is approximately equal to the thickness of the electrode portion 16. The thickness of the support portion 17 is greater than the thickness of the electrode portion 16 and the thickness of each elastic deformation portion 18, except for the inner edge region along the inner edge of the support portion 17 when viewed from the Z-axis direction. The thickness of the inner edge region of the support portion 17 is approximately equal to the thickness of the electrode portion 16 and the thickness of each elastic deformation portion 18. The surface 16a on one side of the electrode portion 16, the surface 18a on one side of each elastic deformation portion 18, and the surface 17c on one side of the inner edge region of the support portion 17 are continuous. The surface 16a of the electrode portion 16, the surface 18a of each elastic deformation portion 18, and the surface 17c of the inner edge region of the support portion 17 are lower than the surface 17a on one side of the support portion 17. The surface 16b on the other side of the electrode portion 16, the surface 18b on the other side of each elastic deformation portion 18, and the surface 17b on the other side of the support portion 17 are continuous. The electrode portion 16 has a plurality of notches 16c formed on both sides (both sides in the circumferential direction) of one end of each elastic deformation portion 18, the notches 16c opening outward.

[0027] The metal pad 13 is formed on the surface 17a of the support portion 17. The metal pad 13 is electrically connected to the electrode portion 16, which is the first electrode 19, via the semiconductor layer 12 as wiring. That is, the semiconductor layer 12 functions as a wiring layer that electrically connects the first electrode 19 and the metal pad 13. As an example, the metal pad 13 is formed in a rectangular film shape so as to extend along one side of the outer edge of the surface 17a that is parallel to the Y-axis direction. The material of the metal pad 13 is, for example, a metal material such as Al. The width of the metal pad 13 in the X-axis direction is, for example, about 0.1 to 1 mm. The width of the metal pad 13 in the Y-axis direction is, for example, about 0.1 to 8 mm. The thickness of the metal pad 13 is, for example, about 1 μm.

[0028] In the first substrate 11 and the semiconductor layer 12 configured as described above, the movable portion 10a is configured by the light transmitting member 14 and the electrode portion 16. The movable portion 10a is a portion that overlaps with the light transmitting region 1a, and is movable in the Z-axis direction by deformation of the multiple elastic deformation portions 18. In other words, the first layer 10 is a movable layer in which the portion that overlaps with the light transmitting region 1a is configured as the movable portion 10a that is movable in the Z-axis direction.

[0029] The first reflection film 50 is disposed on the surface 14b on the other side of the light transmitting member 14. That is, the first layer 10 supports the first reflection film 50. The first reflection film 50 is movable in the Z-axis direction together with the movable part 10a. As an example, the first reflection film 50 is formed in a circular film shape with the straight line L as the center line. The first reflection film 50 is formed, for example, by forming a dielectric film made of aluminum oxide or the like on the surface opposite to the surface 14b of a metal film made of Ag or the like. The outer diameter of the first reflection film 50 is, for example, about 4 to 6 mm. The thickness of the first reflection film 50 is, for example, about 210 nm. The first reflection film 50 may be formed only of a metal film made of Ag or the like, or may be formed only of a dielectric film made of silicon oxide, titanium oxide, aluminum oxide or the like, or may be formed by laminating a plurality of such dielectric films.

[0030] 4 and 6, the second layer 20 is laminated on one side of the first layer 10. The second layer 20 includes a second substrate (substrate) 21, a plurality of second electrodes 22, a light-shielding film 23, a plurality of third electrodes 24, a plurality of electrode pads 25, and a plurality of through electrodes 26. Note that (a) of FIG. 6 is a plan view of the second layer 20, and (b) of FIG. 6 is a bottom view of the second layer 20.

[0031] The second substrate 21 constitutes a part of the light transmission region 1a. The second substrate 21 has a surface 21a on one side and a surface 21b on the other side. The surface 21a is a surface (second surface) opposite to the first layer 10, and the surface 21b is a surface (first surface) on the first layer 10 side. The surface 21b of the second substrate 21 is joined to the surface 17a of the support portion 17 and is spaced apart from the surface 16a of the electrode portion 16, the surface 18a of each elastic deformation portion 18, and the surface 17c of the inner edge region of the support portion 17. The thickness of the second substrate 21 is greater than the thickness of the semiconductor layer 12. As an example, the second substrate 21 is formed in a rectangular plate shape so as to have a pair of side surfaces perpendicular to the X-axis direction and a pair of side surfaces perpendicular to the Y-axis direction. In the Fabry-Perot interference filter 1, when viewed from the Z-axis direction, the outer edge of the second substrate 21 approximately coincides with the outer edge of the support portion 17, except for a cutout portion 210 described later. The material of the second substrate 21 is, for example, a light-transmitting material such as glass or silicon. The width of the second substrate 21 in each of the X-axis direction and the Y-axis direction is, for example, about 11 mm. The thickness of the second substrate 21 is, for example, about 0.5 mm. The support portion 17 and the second substrate 21 are bonded together by airtight bonding such as room temperature bonding, plasma activated bonding, or anodic bonding.

[0032] The second substrate 21 has a notch 210. The notch 210 opens on the opposite side to the light transmitting region 1a in the X-axis direction, exposing the metal pad 13 to the outside. The notch 210 has a first side 210a and a pair of second side surfaces 210b. The first side surface 210a faces outward in the X-axis direction. The pair of second side surfaces 210b face each other in the Y-axis direction. A rounded chamfered surface 210c is formed at the corner between the first side surface 210a and each of the second side surfaces 210b. The width of the notch 210 in the X-axis direction is, for example, about 1 mm. The width of the notch 210 in the Y-axis direction is, for example, about 1 to 10 mm.

[0033] The second electrodes 22 are disposed on the surface 21b of the second substrate 21. The second electrodes 22 surround the light transmitting region 1a when viewed from the Z-axis direction, and face the electrode portion 16 (i.e., the first electrode 19) through a space in the Z-axis direction. As an example, the second electrodes 22 are arranged in the circumferential direction at equal angular intervals, and a slit-shaped gap extending in the radial direction is formed between a pair of adjacent second electrodes 22. As an example, each second electrode 22 is formed in a film shape so as to extend in the circumferential direction. The material of each second electrode 22 is, for example, a metal material such as Au. The width of each second electrode 22 in the radial direction is, for example, about 1 mm. The width of each second electrode 22 in the circumferential direction is, for example, a value obtained by dividing the length of the circumference by the number of second electrodes 22 when the second electrodes 22 are arranged along a circumference, and is, for example, about 4 mm when four second electrodes 22 are arranged along a circumference having a diameter of 5 mm. The thickness of each second electrode 22 is, for example, about 1 to 5 μm. The width of the gap between a pair of adjacent second electrodes 22 is, for example, about 0.1 mm. The distance between the electrode portion 16 (i.e., the first electrode 19) and each second electrode 22 in the initial state (i.e., a state in which no electrostatic force is acting between the first electrode 19 and each second electrode 22) is, for example, about 3 μm.

[0034] In the Fabry-Perot interference filter 1, the second electrodes 22 are a pair of second electrodes 22 located on both sides of the light transmission region 1a in the X-axis direction, and a pair of second electrodes 22 located on both sides of the light transmission region 1a in the Y-axis direction. Each second electrode 22 includes a main body 22a and a pair of protruding parts 22b. The main body 22a is a part extending in the circumferential direction, and faces the first electrode 19 via a space in the Z-axis direction. The pair of protruding parts 22b are parts protruding outward in the radial direction from the main body 22a, and are located on both sides of the elastic deformation part 18 in the circumferential direction when viewed from the Z-axis direction (see FIG. 5). The main body 22a has a notch 22c that opens outward between the pair of protruding parts 22b. When viewed from the Z-axis direction, the notch 22c overlaps one end of the elastic deformation part 18 and the pair of notches 16c on both sides thereof (see FIG. 5).

[0035] The light-shielding film 23 is disposed on the surface 21a of the second substrate 21. That is, the light-shielding film 23 is formed on one side of the second layer 20 on the second layer 20. The light-shielding film 23 is a first metal film 27 surrounding the light-transmitting region 1a when viewed from the Z-axis direction. The light-shielding film 23 extends along the outer edge of the light-transmitting region 1a when viewed from the Z-axis direction. In the Fabry-Perot interference filter 1, the light-shielding film 23 extends in an annular shape along the outer edge of the light-transmitting region 1a when viewed from the Z-axis direction. The light-shielding film 23 has an opening 23a that overlaps with the light-transmitting region 1a when viewed from the Z-axis direction. The material of the light-shielding film 23 is, for example, a metal material such as Au. The inner diameter of the light-shielding film 23 (i.e., the diameter of the opening 23a) is, for example, about 3 to 5 mm. The outer diameter of the light-shielding film 23 is, for example, about 5 to 7 mm. The thickness of the light-shielding film 23 is, for example, about 1 to 5 μm. Note that the light-shielding film 23 (that is, the first metal film 27) does not function as an electrode or wiring.

[0036] The third electrodes 24 are disposed on the surface 21a of the second substrate 21. The third electrodes 24 are the second metal films 28 surrounding the first metal film 27 when viewed from the Z-axis direction. That is, the third electrodes 24 surround the light-transmitting region 1a when viewed from the Z-axis direction. As an example, the third electrodes 24 are arranged in the circumferential direction at equal angular intervals, and a slit-shaped gap extending in the radial direction is formed between a pair of adjacent third electrodes 24. As an example, each third electrode 24 is formed in a film shape extending in the circumferential direction, and a slit-shaped gap extending in the circumferential direction is formed between the light-shielding film 23 and each third electrode 24. The material of each third electrode 24 is, for example, a metal material such as Au. The width of each third electrode 24 in the radial direction is, for example, about 1 mm. The width of each third electrode 24 in the circumferential direction is, for example, a value obtained by dividing the length of the circumference by the number of third electrodes 24 when a plurality of third electrodes 24 are arranged along the circumference, and is, for example, about 4 mm when four third electrodes 24 are arranged along a circumference having a diameter of 5 mm. The thickness of each third electrode 24 is, for example, about 1 to 5 μm. The width of the gap between a pair of adjacent third electrodes 24 is, for example, about 0.1 mm. The width of the gap between the light-shielding film 23 and each third electrode 24 is, for example, about 0.1 mm.

[0037] In the Fabry-Perot interference filter 1, the multiple third electrodes 24 are a pair of third electrodes 24 located on both sides of the light-shielding film 23 in the X-axis direction, and a pair of third electrodes 24 located on both sides of the light-shielding film 23 in the Y-axis direction. When viewed from the Z-axis direction, each third electrode 24 is located radially outward from the main body 22a of each second electrode 22. When viewed from the Z-axis direction, each third electrode 24 overlaps with a pair of protrusions 22b of each second electrode 22.

[0038] The electrode pads 25 are arranged on the surface 21a of the second substrate 21 together with the wirings 25a. Each of the third electrodes 24 is electrically connected to each of the electrode pads 25 via each of the wirings 25a. In the Fabry-Perot interference filter 1, each of the electrode pads 25 is arranged at each of the four corners of the rectangular surface 21a and is formed in a circular film shape. Each of the wirings 25a connects one end of the third electrode 24 in the circumferential direction to the electrode pad 25 in the corresponding third electrode 24 and electrode pad 25. The material of each of the electrode pads 25 and each of the wirings 25a is, for example, a metal material such as Au. The outer diameter of each of the electrode pads 25 is, for example, about 0.5 to 1 mm. The width of each of the wirings 25a is, for example, about 0.1 to 0.5 mm. The thickness of each of the electrode pads 25 and each of the wirings 25a is, for example, about 1 to 5 μm.

[0039] In the Fabry-Perot interference filter 1, the light-shielding film 23 and the multiple third electrodes 24 are made of the same material. That is, the first metal film 27 and the multiple second metal films 28 are made of the same material. The multiple electrode pads 25 and the multiple wirings 25a are made of the same material as the first metal film 27 and the second metal film 28 and are integral with the multiple third electrodes 24.

[0040] The plurality of through electrodes 26 are provided on the second substrate 21. The plurality of through electrodes 26 are disposed in a plurality of through holes formed in the second substrate 21 so as to extend in the Z-axis direction and open to the surface 21a and the surface 21b, and the plurality of through holes are airtightly sealed. Each second electrode 22 is electrically connected to each third electrode 24 through at least two of the plurality of through electrodes 26. In the Fabry-Perot interference filter 1, each through electrode 26 connects each protrusion 22b of the second electrode 22 to the third electrode 24 in the second electrode 22 and the third electrode 24 corresponding to each other. That is, in the second electrode 22 and the third electrode 24 corresponding to each other, the second electrode 22 is electrically connected to the third electrode 24 through two through electrodes 26. The material of each through electrode 26 is, for example, a metal material such as Au. The length of each through electrode 26 in the Z-axis direction is, for example, about 0.5 mm. The width of each of the through electrodes 26 in the direction perpendicular to the Z-axis direction is, for example, about 0.1 mm. Note that the through electrodes 26 do not necessarily need to airtightly close the through holes formed in the second substrate 21.

[0041] 4 and 7, the third layer 30 is laminated on the other side of the first layer 10. The third layer 30 includes a third substrate 31 and a plurality of protrusions 32. Note that (a) of Fig. 7 is a plan view of the third layer 30, and (b) of Fig. 7 is a bottom view of the third layer 30.

[0042] The third substrate 31 constitutes a part of the light transmitting region 1a. The third substrate 31 has a surface 31a on one side and a surface 31b on the other side. The surface 31a is the surface on the first layer 10 side, and the surface 31b is the surface opposite to the first layer 10. The surface 31a of the third substrate 31 is joined to the surface 15b on the other side of the support member 15. The thickness of the third substrate 31 is greater than the thickness of the semiconductor layer 12. As an example, the third substrate 31 is formed in a rectangular plate shape so as to have a pair of side surfaces perpendicular to the X-axis direction and a pair of side surfaces perpendicular to the Y-axis direction. In the Fabry-Perot interference filter 1, when viewed from the Z-axis direction, the outer edge of the third substrate 31 approximately coincides with the outer edge of the support member 15. The material of the third substrate 31 is a light transmitting material such as glass or silicon. The width of the third substrate 31 in each of the X-axis direction and the Y-axis direction is, for example, about 11 mm. The thickness of the third substrate 31 is, for example, about 0.5 mm. The support member 15 and the third substrate 31 are joined together by airtight bonding such as room temperature bonding, plasma activation bonding, or metal diffusion bonding.

[0043] The plurality of protrusions 32 are disposed on the surface 31a of the third substrate 31. The plurality of protrusions 32 surround the light-transmitting region 1a when viewed from the Z-axis direction, and face an outer edge region of the first reflective film 50 located outside the light-transmitting region 1a in the Z-axis direction. As an example, each protrusion 32 is formed in a cylindrical shape. The material of each protrusion 32 is, for example, silicon oxide, silicon nitride, or the like. The outer diameter of each protrusion is, for example, about 0.1 mm. The height of each protrusion in the Z-axis direction is, for example, about 50 nm.

[0044] The second reflection film 60 is disposed on the surface 31a of the third substrate 31. That is, the third layer 30 supports the second reflection film 60. The outer edge region of the second reflection film 60 located outside the light transmission region 1a covers the multiple protrusions 32. As an example, the second reflection film 60 is formed in a circular film shape with the straight line L as the center line. In the Fabry-Perot interference filter 1, in the initial state, the portion of the second reflection film 60 located on each protrusion 32 is in contact with the outer edge region of the first reflection film 50. As a result, in the light transmission region 1a, a space is formed between the first reflection film 50 and the second reflection film 60, and contact between the first reflection film 50 and the second reflection film 60 is prevented. The second reflection film 60 is formed, for example, by forming a dielectric film made of aluminum oxide or the like on the surface opposite to the surface 14b of a metal film made of Ag or the like. The outer diameter of the second reflection film 60 is, for example, about 5 to 8 mm. The thickness of the second reflective film 60 is, for example, about 210 nm. The distance between the first reflective film 50 and the second reflective film 60 in the initial state is, for example, about 50 nm. The second reflective film 60 may be composed only of a metal film made of Ag or the like, or may be composed only of a dielectric film made of silicon oxide, titanium oxide, aluminum oxide or the like, or may be composed of a plurality of such dielectric films stacked together.

[0045] The absorbing film 70 is disposed on the surface 31b of the third substrate 31. That is, the absorbing film 70 is located on the other side of the first reflecting film 50 and the second reflecting film 60. One side surface 70a of the absorbing film 70 has light absorbing properties, and the other side surface 70b of the absorbing film 70 has light reflecting properties. The absorbing film 70 surrounds the light transmitting region 1a when viewed from the Z-axis direction. The absorbing film 70 has an opening 70c that overlaps with the light transmitting region 1a when viewed from the Z-axis direction. In the Fabry-Perot interference filter 1, the outer edge of the absorbing film 70 approximately coincides with the outer edge of the third substrate 31 when viewed from the Z-axis direction. The diameter of the opening 70c is, for example, about 3 to 5 mm.

[0046] As shown in FIG. 8, the absorption film 70 has a multilayer structure including a reflective layer 71, a resonant layer 72, and an absorbing layer 73. The reflective layer 71, the resonant layer 72, and the absorbing layer 73 are laminated in this order from the side opposite to the third substrate 31. That is, the resonant layer 72 is disposed between the reflective layer 71 and the third substrate 31, and the absorbing layer 73 is disposed between the resonant layer 72 and the third substrate 31. The reflective layer 71 is a metal layer that does not transmit light incident on the surface 70a on one side (at least light in a wavelength band that transmits through the first reflective film 50 and the second reflective film 60 whose distance from each other is variable). At the wavelength of light incident on the surface 70a on one side, the optical transmittance inside the resonant layer 72 is greater than the optical transmittance inside the absorbing layer 73. At the wavelength of light incident on the surface 70a on one side, the optical reflectance of the surface of the reflective layer 71 is greater than the optical reflectance of the surface of the resonant layer 72. The absorbing film 70 thus configured has a surface 70a on one side that is light absorbing and a surface 70b on the other side that is light reflective. The material of the reflective layer 71 is, for example, a metal material such as Cr, Ti, or Al. The thickness of the reflective layer 71 is, for example, 100 nm or more. The material of the resonant layer 72 is, for example, a dielectric material such as SiO2. The thickness of the resonant layer 72 is, for example, within a range of ±20% centered on an integral multiple of a quarter of the wavelength (reference wavelength such as a central wavelength) of the light incident on the surface 70a on one side. The material of the absorbing layer 73 is, for example, a metal material such as Cr or Ti, or a silicide. The thickness of the absorbing layer 73 is, for example, about 1 to 10 nm.

[0047] As shown in FIG. 9, the first layer 10 and the second layer 20 have a first region R1, a second region R2, and a third region R3. The first region R1 is a region including the movable part 10a when viewed from the Z-axis direction. In the Fabry-Perot interference filter 1, the first region R1 is a region located inside the inner edge of the surface 17a of the support part 17 when viewed from the Z-axis direction. The second region R2 is a region surrounding the first region R1 when viewed from the Z-axis direction. In the Fabry-Perot interference filter 1, the second region R2 is a region overlapping with a region of the surface 17a of the support part 17 except for a region corresponding to the notch part 210 when viewed from the Z-axis direction. The third region R3 is a region located outside the second region R2 and on one side in the X-axis direction when viewed from the Z-axis direction. In the Fabry-Perot interference filter 1, the third region R3 is a region overlapping with the notch part 210 when viewed from the Z-axis direction. That is, the cutout portion 210 is a cutout portion formed by cutting out the outer edge of the second substrate 21 so as to overlap with the third region R3 when viewed from the Z-axis direction. Note that (a) of Fig. 9 is a plan view of the Fabry-Perot interference filter 1, and (b) of Fig. 9 is a cross-sectional view of the Fabry-Perot interference filter 1 between the first layer 10 and the second layer 20. In (b) of Fig. 9, the boundary between the first region R1 and the second region R2 and the boundary between the second region R2 and the third region R3 are indicated by dashed lines.

[0048] The electrode portion 16 and each elastic deformation portion 18 are separated from the second layer 20 in the first region R1. Specifically, the surface 16a of the electrode portion 16 and the surface 18a of each elastic deformation portion 18 are separated from the surface 21b of the second substrate 21 and each second electrode 22 in the first region R1 (see FIG. 4). That is, the first region R1 is a region where the electrode portion 16 and each elastic deformation portion 18 are separated from the second layer 20. The support portion 17 is bonded to the second layer 20 in the second region R2. Specifically, the surface 17a of the support portion 17 is bonded to the surface 21b of the second substrate 21 in the second region R2 (see FIG. 4). That is, the second region R2 is a region where the support portion 17 is bonded to the second layer 20. The support portion 17 is exposed to the space in the third region R3. Specifically, surface 17a of support portion 17 is exposed to space in third region R3. That is, third region R3 is a region where support portion 17 is exposed to space. Metal pad 13 is formed on support portion 17 in third region R3. Specifically, metal pad 13 is formed on surface 17a of support portion 17 in third region R3.

[0049] The width W1 of the metal pad 13 in the Y-axis direction is larger than the distance D between the first region R1 and the third region R3 in the X-axis direction. The width W2 of the third region R3 in the X-axis direction is smaller than the width W3 of the third region R3 in the Y-axis direction. The width W1 of the metal pad 13 in the Y-axis direction is larger than the width W4 of the opening 23a of the light-shielding film 23 (the light-shielding film arranged on one side in the Z-axis direction with respect to the first layer 10 and the second layer 20) in the Y-axis direction. In the Y-axis direction, both ends 13a of the metal pad 13 are located outside the opening 23a of the light-shielding film 23. The width W1 is the maximum width of the metal pad 13 in the Y-axis direction. The width W2 is the maximum width of the third region R3 in the X-axis direction. The width W3 is the maximum width of the third region R3 in the Y-axis direction. The width W4 is the maximum width of the opening 23a of the light-shielding film 23 in the Y-axis direction. The distance D is the minimum distance between the first region R1 and the third region R3 in the X-axis direction. In addition, in the Fabry-Perot interference filter 1, the width W1 of the metal pad 13 in the Y-axis direction is larger than the width (maximum width of the opening 70c in the Y-axis direction) of the absorbing film 70 (a light-shielding film arranged on the other side in the Z-axis direction relative to the first layer 10 and the second layer 20) in the Y-axis direction.

[0050] The first region R1 includes a plurality of regions R4. When viewed from the Z-axis direction, each region R4 is a region between the electrode portion 16 and the support portion 17 that does not overlap with the plurality of elastic deformation portions 18, and is a region between a pair of adjacent elastic deformation portions 18 when viewed from the Z-axis direction. The plurality of through electrodes 26 are located in the plurality of regions R4 when viewed from the Z-axis direction. In the Fabry-Perot interference filter 1, two through electrodes 26 are located in each region R4 when viewed from the Z-axis direction. In FIG. 9B, each region R4 is indicated by dot hatching.

[0051] In the Fabry-Perot interference filter 1 configured as above, when a voltage is applied to the first electrode 19 and the second electrodes 22 via the metal pad 13 and the electrode pads 25, a potential difference occurs between the first electrode 19 and the second electrodes 22, and an electrostatic force corresponding to the potential difference occurs between the first electrode 19 and the second electrodes 22. When an electrostatic force occurs between the first electrode 19 and the second electrodes 22, the movable part 10a moves to one side, and the distance between the first reflection film 50 and the second reflection film 60 changes. Here, the wavelength of light passing through the light transmission region 1a of the Fabry-Perot interference filter 1 depends on the distance between the first reflection film 50 and the second reflection film 60. Therefore, by adjusting the voltage applied to the first electrode 19 and the second electrodes 22 (i.e., the potential difference occurring between the first electrode 19 and the second electrodes 22), the wavelength of light passing through the Fabry-Perot interference filter 1 can be selected. In the Fabry-Perot interference filter 1, the first substrate 11, the semiconductor layer 12, the second substrate 21 and the third substrate 31 are hermetically bonded to one another, and the multiple through holes formed in the second substrate 21 are hermetically blocked by multiple through electrodes 26, so that the movable part 10a moves in the Z-axis direction in the airtight space.

[0052] As described above, in the Fabry-Perot interference filter 1, in the second substrate 21 of the second layer 20, the plurality of through electrodes 26 electrically connect the plurality of second electrodes 22 and the plurality of third electrodes 24, and when viewed from the Z-axis direction, the plurality of through electrodes 26 are located in a region R4 between the electrode portion 16 and the support portion 17 that does not overlap with the plurality of elastic deformation portions 18. This ensures flatness of at least the region of each second electrode 22 facing the first electrode 19, so that a desired electrostatic force can be reliably generated between the first electrode 19 and each second electrode 22. Furthermore, even if the end of each through electrode 26 on the second electrode 22 side is formed in a convex shape, physical interference between the end of each through electrode 26 on the second electrode 22 side and each elastic deformation portion 18 can be suppressed. Furthermore, since a sufficient bonding area between the support portion 17 of the first layer 10 and the second substrate 21 of the second layer 20 can be ensured, the stability of the bonding between the first layer 10 and the second layer 20 can be improved. As described above, the Fabry-Perot interference filter 1 can ensure reliability.

[0053] The through electrode 26 is generally formed by embedding a metal material in a through hole formed in the second substrate 21, plating the inner surface of the through hole formed in the second substrate 21 with a metal, or the like, and unevenness is likely to be formed in the second electrode 22 and the third electrode 24 at the location where both ends of the through electrode 26 are connected. Therefore, when viewed from the Z-axis direction, positioning the through electrode 26 in the region R4 between the electrode portion 16 and the support portion 17 that does not overlap with the multiple elastic deformation portions 18 is extremely important in terms of reliably generating a desired electrostatic force between the first electrode 19 and each second electrode 22 while sufficiently securing a bonding region between the support portion 17 of the first layer 10 and the second substrate 21 of the second layer 20.

[0054] In the Fabry-Perot interference filter 1, the third layer 30 laminated on the first layer 10 on the other side of the first layer 10 supports the second reflective film 60. This allows the movable part 10a of the first layer 10 to be protected from both sides by the second layer 20 and the third layer 30.

[0055] In the Fabry-Perot interference filter 1, when viewed from the Z-axis direction, at least two of the multiple through electrodes 26 are located in each region R4 between a pair of adjacent elastic deformation parts 18 among the multiple elastic deformation parts 18. As a result, even when multiple through electrodes 26 are provided on the second substrate 21 of the second layer 20, the ends of the multiple through electrodes 26 can be arranged in a well-balanced manner with respect to the electrode part 16, the support part 17, and the multiple elastic deformation parts 18 of the first layer 10. In addition, since the movable part 10a is supported by the multiple elastic deformation parts 18, the parallelism of the first reflection film 50 with respect to the second reflection film 60 can be more reliably ensured. In addition, since one second electrode 22 and one third electrode 24 are electrically connected by the multiple through electrodes 26, the wiring resistance can be reduced and the potential difference between one second electrode 22 and one third electrode 24 can be reduced.

[0056] In the Fabry-Perot interference filter 1, the multiple elastic deformation parts 18 are conductive. When viewed from the Z-axis direction, if an end part of at least one through electrode 26 on the second electrode 22 side overlaps with at least one elastic deformation part 18 having conductivity, the magnitude of the electrostatic force generated between the end part and the elastic deformation part 18 may vary when the shape of the end part varies, and the parallelism of the first reflection film 50 to the second reflection film 60 may not be ensured. According to the Fabry-Perot interference filter 1, when viewed from the Z-axis direction, the end part of each through electrode 26 on the second electrode 22 side does not overlap with each elastic deformation part 18 having conductivity, so that the parallelism of the first reflection film 50 to the second reflection film 60 can be ensured even if the shape of the end part of each through electrode 26 on the second electrode 22 side varies.

[0057] In the Fabry-Perot interference filter 1, the first electrode 19 and the metal pad 13 are electrically connected via the semiconductor layer 12 of the first layer 10. This eliminates the need to form a wiring layer between the first layer 10 and the second layer 20 for electrically connecting the first electrode 19 and the metal pad 13, and therefore the stability of the junction between the first layer 10 and the second layer 20 can be improved. In addition, the width W1 of the metal pad 13 in the Y-axis direction is larger than the distance D between the first region R1 and the third region R3 in the X-axis direction, and the width W2 of the third region R3 in the X-axis direction is smaller than the width W3 of the third region R3 in the Y-axis direction. This increases the contact area between the metal pad 13 and the support portion 17 of the semiconductor layer 12, thereby increasing the probability of forming an ohmic contact between the metal pad 13 and the support portion 17 of the semiconductor layer 12. Furthermore, since the distance between the metal pad 13 and the first electrode 19 can be reduced, it is possible to suppress the occurrence of a potential difference in the first electrode 19, and as a result, it is possible to suppress the distance between the first reflection film 50 and the second reflection film 60 from varying depending on the location. As a result, the Fabry-Perot interference filter 1 can ensure reliability.

[0058] In the Fabry-Perot interference filter 1, the second substrate 21 has a notch 210 formed by cutting out the outer edge of the second substrate 21 so as to overlap with the third region R3 when viewed from the Z-axis direction. This allows external wiring such as wires to be easily and reliably connected to the metal pads 13.

[0059] The present invention is not limited to the above embodiment. For example, the second layer 20 may include one second electrode 22 facing the first electrode 19 through a space in the Z-axis direction, and one second metal film 28 surrounding the first metal film 27 when viewed from the Z-axis direction. In this case, one second electrode 22 may be electrically connected to one second metal film 28 through at least one through electrode 26. In other words, the second layer 20 may include one third electrode 24 surrounding the light-shielding film 23 when viewed from the Z-axis direction.

[0060] The second layer 20 may include a plurality of first metal films 27 surrounding the light-transmitting region 1a when viewed from the Z-axis direction. In that case, each second electrode 22 may be electrically connected to each first metal film 27 via at least one through electrode 26. The second layer 20 may also include one second electrode 22 facing the first electrode 19 via a space in the Z-axis direction, and one first metal film 27 surrounding the light-transmitting region 1a when viewed from the Z-axis direction. In that case, one second electrode 22 may be electrically connected to one first metal film 27 via at least one through electrode 26. As described above, in the second layer 20, the first metal film 27 may be configured as the third electrode 24, and the second metal film 28 may be configured as the light-shielding film 23.

[0061] The first electrode 19 may be provided in the electrode section 16. As an example, as shown in Fig. 10, the first electrode 19 may be disposed on one surface of the electrode section 16. In this example, the first electrode 19 is a single electrode surrounding the light transmitting region 1a when viewed from the Z-axis direction, and faces a plurality of second electrodes 22 via spaces in the Z-axis direction.

[0062] The second layer 20 may further include a fourth electrode disposed on the surface 21a of the second substrate 21. In that case, the fourth electrode may be electrically connected to the first electrode 19 via at least one through electrode 26.

[0063] The first layer 10 includes a plurality of first electrodes 19 surrounding the light-transmitting region 1a when viewed from the Z-axis direction, and the second layer 20 may further include a plurality of fourth electrodes surrounding the light-transmitting region 1a when viewed from the Z-axis direction. In this case, each of the first electrodes 19 may be electrically connected to each of the fourth electrodes via at least one through electrode 26. This allows, for example, fine adjustment of the potential applied to each of the first electrodes 19 and fine adjustment of the potential applied to each of the second electrodes 22 so that the first reflection film 50 and the second reflection film 60 are parallel to each other.

[0064] At least one third metal film surrounding the second metal film 28 may be disposed on the surface 21a of the second substrate 21. With this configuration, when light is incident into the Fabry-Perot interference filter 1 from the surface 21a of the second substrate 21 of the second layer 20, it is possible to more reliably prevent the light from traveling into the Fabry-Perot interference filter 1 from the region of the surface 21a that does not face the first reflection film 50 and the second reflection film 60, and as a result, it is possible to more reliably prevent the emission of stray light from the Fabry-Perot interference filter 1 due to multiple reflections or the like in the Fabry-Perot interference filter 1.

[0065] In the Fabry-Perot interference filter 1, at least the end of the through electrode 26 on the second electrode 22 side needs to be located in region R4 between the electrode portion 16 and the support portion 17 that does not overlap with the elastic deformation portion 18 when viewed from the Z-axis direction.

[0066] In the Fabry-Perot interference filter 1, the width W1 of the metal pad 13 in the Y-axis direction may be larger than the width of at least one of the first reflection film 50 and the second reflection film 60 in the Y-axis direction (the maximum width of at least one of the first reflection film 50 and the second reflection film 60 in the Y-axis direction). In this case, the probability of forming an ohmic contact between the metal pad 13 and the support portion 17 of the semiconductor layer 12 can be further increased. Furthermore, in the Fabry-Perot interference filter 1, both ends 13a of the metal pad 13 may be located outside at least one of the first reflection film 50 and the second reflection film 60 in the Y-axis direction. In this case, the generation of a potential difference in the first electrode 19 can be more reliably suppressed, and as a result, the distance between the first reflection film 50 and the second reflection film 60 can be more reliably suppressed from changing depending on the location.

[0067] The metal pad 13 may be a plurality of metal pads 13 electrically connected to the first electrode 19 via the semiconductor layer 12. As an example, as shown in FIG. 11, a plurality of metal pads 13 may be arranged on a region of the surface 17a of the support portion 17 of the semiconductor layer 12 that is exposed to the outside at the cutout portion 210 of the second substrate 21. In this example, each metal pad 13 is formed in a rectangular shape when viewed from the Z-axis direction, and the plurality of metal pads 13 are lined up in the Y-axis direction. In this way, when a plurality of metal pads 13 are formed on the support portion 17 in the third region R3 (see FIG. 9(b)), the width W1 of the metal pad 13 in the Y-axis direction means the total value obtained by adding up the widths of the respective metal pads 13 in the Y-axis direction.

[0068] The metal pad 13 may be formed in a region of the support portion 17 of the semiconductor layer 12 that is exposed to the space. As an example, as shown in FIG. 12 and FIG. 13, the metal pad 13 may be disposed on a surface 17d of a step portion 170 formed in the support portion 17. In this example, the step portion 170 is formed in the support portion 17 along a part of the outer edge of the support portion 17. The surface 17d of the step portion 170 is a surface lower than the surface 17a of the support portion 17 and is separated from the second layer 20. That is, when viewed from the Z-axis direction, the surface 17d of the step portion 170 corresponds to the third region R3 (see FIG. 9(b)). In this example, the width of the notch portion 210 in the Y-axis direction is smaller than the widths of the step portion 170 and the metal pad 13 in the Y-axis direction. In this case, external wiring such as wires can be easily and reliably connected to the metal pad 13 via the notch portion 210.

[0069] The absorbing film 70 may have light absorbing properties not only on the surface 70a on one side but also on the surface 70b on the other side. An example of the absorbing film 70 having light absorbing properties on both surfaces 70a, 70b will be described. As shown in FIG. 14, the absorbing film 70 has a multilayer structure including a reflective layer 71, a pair of resonant layers 72, and a pair of absorbing layers 73. The pair of resonant layers 72 are arranged on both sides of the reflective layer 71 in the Z-axis direction, and the pair of absorbing layers 73 are arranged on both sides of the pair of resonant layers 72 in the Z-axis direction. The reflective layer 71 is a metal layer that does not transmit light incident on the surface 70a on one side and light incident on the surface 70b on the other side. At the wavelength of light incident on the surface 70a on one side, the light transmittance inside the resonant layer 72 on one side is greater than the light transmittance inside the absorbing layer 73 on one side. At the wavelength of light incident on the surface 70a on one side, the light reflectance of the surface of the reflective layer 71 on one side is greater than the light reflectance of the surface of the resonant layer 72 on one side. At the wavelength of light incident on the other surface 70a, the optical transmittance inside the other resonant layer 72 is greater than the optical transmittance inside the other absorbing layer 73. At the wavelength of light incident on the other surface 70a, the optical reflectance of the surface of the other reflective layer 71 is greater than the optical reflectance of the surface of the other resonant layer 72. In the absorbing film 70 configured in this manner, both surfaces 70a, 70b have optical absorptivity.

[0070] In the Fabry-Perot interference filter 1, the third layer 30 may not be laminated on the first layer 10 on the other side of the first layer 10, and the second layer 20 may support the second reflective film 60. Note that even when the third layer 30 is laminated on the first layer 10, the second layer 20, rather than the third layer 30, may support the second reflective film 60. [Explanation of symbols]

[0071] 1...Fabry-Perot interference filter, 1a...light transmitting region, 10...first layer (movable layer), 10a...movable portion, 16...electrode portion, 17...support portion, 18...elastic deformation portion, 19...first electrode, 20...second layer, 21...second substrate (substrate), 21a...surface (second surface), 21b...surface (first surface), 22...second electrode, 24...third electrode, 26...through electrode, 30...third layer, 50...first reflective film, 60...second reflective film, R4...region.

Claims

1. A first reflective film; a second reflective film facing the first reflective film across a space in the light transmitting region; a first layer including a first electrode and supporting the first reflective film; a second layer laminated on the first layer on one side in a first direction in which the first reflective film and the second reflective film face each other, The second layer is a substrate having a first surface on the first layer side and a second surface on the opposite side to the first layer; a second electrode disposed on the first surface and facing the first electrode in the first direction with a space therebetween; a third electrode disposed on the second surface; a through electrode provided on the substrate and electrically connecting the second electrode and the third electrode; the first layer is a movable layer having a portion overlapping with the light transmitting region configured as a movable portion movable in the first direction, The first layer is an electrode portion provided on the movable portion and having the first electrode or being the first electrode; a support portion surrounding the movable portion when viewed from the first direction and joined to the second layer; an elastic deformation portion connecting the electrode portion and the support portion, A Fabry-Perot interference filter, wherein the end of the through electrode on the second electrode side is located in a region between the electrode portion and the support portion that does not overlap with the elastic deformation portion when viewed from the first direction.

2. 2. The Fabry-Perot interference filter according to claim 1, further comprising a third layer stacked on the first layer on the other side in the first direction and supporting the second reflective film.

3. the elastic deformation portion includes a plurality of elastic deformation portions connecting the electrode portion and the support portion, 2. The Fabry-Perot interference filter according to claim 1, wherein the end of the through electrode is located in a region between a pair of adjacent elastic deformation portions among the plurality of elastic deformation portions when viewed from the first direction.

4. the through electrodes are a plurality of through electrodes electrically connecting the second electrode and the third electrode, 4. The Fabry-Perot interference filter according to claim 3, wherein a plurality of ends of the plurality of through electrodes on the second electrode side are located in the region between the pair of elastic deformation portions when viewed from the first direction.

5. The Fabry-Perot interference filter according to claim 1 , wherein the through electrode is located in a region between the electrode portion and the support portion that does not overlap with the elastic deformation portion when viewed from the first direction.

6. The Fabry-Perot interference filter according to claim 1 , wherein the elastic deformation portion has electrical conductivity.

Images