Fabry-perot interference filter

Abstract

To provide a Fabry-Perot interference filter that can appropriately move a first reflection film relative to a second reflection film.SOLUTION: A Fabry-Perot interference filter 1 comprises a first reflection film 50, a second reflection film, a first layer 10 including a first electrode 19, a second electrode, and a second layer. The first layer 10 includes a frame-like stationary part 10b, a movable part 10a provided with the first reflection film 50, and a plurality of elastic deformation parts 18 connecting the stationary part 10b and the movable part 10a. A side face Sb inside the stationary part 10b includes a plurality of first areas R1 each extending linearly when seen from a Z-axis direction, and a plurality of second areas R2 each connecting the pair of first areas R1 adjacent to each other, of the plurality of first areas R1. The elastic deformation parts 18 are connected with the first areas R1, respectively. A distance between each of the second areas R2 and the movable part 10a is larger than a distance between each of the first areas R1 and the movable part 10a.SELECTED DRAWING: Figure 5

Description

[Technical field]

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

[0002] A Fabry-Perot interference filter is known which comprises a first reflective film and a second reflective film facing each other, a movable layer supporting the first reflective film so that it can move, and a fixed layer supporting the second reflective film, in which the movable layer includes a frame-shaped fixed section joined to the fixed layer, a movable section arranged inside the fixed section, the movable section provided with the first reflective film, and a plurality of elastic deformation sections connecting the fixed section and the movable section, and each elastic deformation section is connected to an inner side surface of the fixed section which is formed into a cylindrical shape (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-33257 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned Fabry-Perot interference filter, since each elastic deformation part is connected to the inner side surface of the fixed part, which is formed into a cylindrical shape, stress tends to concentrate on the end part on the side surface side of each elastic deformation part, and if the joining position of the fixed part to the fixed layer is misaligned during the manufacture of the Fabry-Perot interference filter, the characteristics of each elastic deformation part are likely to be affected. Therefore, there is a risk that the first reflection film cannot be moved appropriately in the movable layer.

[0005] An object of the present invention is to provide a Fabry-Perot interference filter in which a first reflective film can be appropriately moved relative to a second reflective film. [Means for solving the problem]

[0006] The Fabry-Perot interference filter of the present invention comprises: [1] "a first reflective film; a second reflective film facing the first reflective film across a space in a light transmitting region; a first electrode; a movable layer that supports the first reflective film so as to be movable in a direction in which the first reflective film and the second reflective film face each other; a second electrode that faces the first electrode across a space in the direction; and a first fixed layer that is laminated on the movable layer and supports at least one of the second reflective film and the second electrode, the movable layer comprising a frame-shaped fixed portion bonded to the first fixed layer, and a frame-shaped fixed portion of the fixed portion. a movable section disposed on the inside and provided with the first reflective film, and a plurality of elastic deformation sections connecting the fixed section and the movable section, wherein the inner side surfaces of the fixed section each extend in a straight line when viewed from the direction, and the fixed section includes a plurality of first regions to which the plurality of elastic deformation sections are connected, and a plurality of second regions each connecting a pair of adjacent first regions among the plurality of first regions, wherein the distance between each of the plurality of second regions and the movable section is greater than the distance between each of the plurality of first regions and the movable section.

[0007] In the above Fabry-Perot interference filter, each elastic deformation part is connected to each first region extending linearly on the inner side surface of the fixed part. As a result, it is possible to suppress stress concentration on the end part on the side surface side of each elastic deformation part, compared to, for example, a case where each elastic deformation part is connected to each region extending in an arc shape on the inner side surface of the fixed part. In addition, even if the bonding position of the fixed part to the first fixed layer is shifted during the manufacture of the Fabry-Perot interference filter, it is possible to suppress the effect on the characteristics of each elastic deformation part. Furthermore, in the above Fabry-Perot interference filter, each second region connects a pair of adjacent first regions on the inner side surface of the fixed part, and the distance between each second region and the movable part is greater than the distance between each first region and the movable part. As a result, it is possible to secure a sufficient bonding area between the first fixed layer and the fixed part to stably support the movable layer, while securing a sufficient gap between each second region and the movable part to smoothly move the movable part. As described above, according to the above Fabry-Perot interference filter, it is possible to appropriately move the first reflection film relative to the second reflection film.

[0008] The Fabry-Perot interference filter of the present invention may be [2] "the Fabry-Perot interference filter according to the above [1], in which each of the second regions extends in an outwardly convex arc shape when viewed from the direction." With this Fabry-Perot interference filter, a sufficient gap can be secured between each second region and the movable part, allowing the movable part to move more smoothly.

[0009] The Fabry-Perot interference filter of the present invention may be [3] "the Fabry-Perot interference filter according to the above [2], in which each of the plurality of third regions facing at least the plurality of second regions among the side surfaces of the movable portion extends in an outwardly convex arc shape when viewed from the direction." According to the Fabry-Perot interference filter, the gap between each second region and the movable portion is uniform throughout each second region, so that the first reflective film can be moved stably.

[0010] The Fabry-Perot interference filter of the present invention may be [4] "a Fabry-Perot interference filter according to any one of the above [1] to [3], in which the length of each of the plurality of first regions is greater than the length of each of the plurality of second regions when viewed from the direction." According to the Fabry-Perot interference filter, the length of each of the linearly extending first regions is sufficiently ensured, so that even if the joining position of the fixing portion relative to the first fixing layer is misaligned during the manufacture of the Fabry-Perot interference filter, it is possible to reliably suppress the effect on the characteristics of each elastic deformation portion. In addition, since the gap between each second region and the movable portion is more sufficiently ensured, the movable portion can be moved more smoothly.

[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], in which the length of each of the plurality of first regions is greater than the length of each of the plurality of elastic deformation parts when viewed from the direction." According to the Fabry-Perot interference filter, the length of each of the linearly extending first regions is sufficiently ensured, so that even if the joining position of the fixing part relative to the first fixing layer is shifted during the manufacture of the Fabry-Perot interference filter, it is possible to reliably suppress the influence on the characteristics of each elastic deformation part. In addition, the gap between each second region and the movable part is more sufficiently ensured, so that the movable part can be moved more smoothly.

[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 length of each of the second regions is greater than the width of each of the elastic deformation portions when viewed from the direction." According to this Fabry-Perot interference filter, the bonding area between the first fixed layer and the fixed portion is more sufficiently ensured, so that the movable layer can be supported more stably.

[0013] The Fabry-Perot interference filter of the present invention may be [7] "the Fabry-Perot interference filter according to any one of the above [1] to [6], in which, when viewed from the direction, the length of each of the second regions is greater than the length of each of the elastic deformation portions." According to this Fabry-Perot interference filter, the bonding area between the first fixed layer and the fixed portion is more sufficiently ensured, so that the movable layer can be supported more stably.

[0014] The Fabry-Perot interference filter of the present invention may be [8] "the Fabry-Perot interference filter according to any one of the above [1] to [7], in which, when viewed from the direction, the length of each of the second regions is greater than the distance between each of the second regions and the movable portion." According to this Fabry-Perot interference filter, the bonding area between the first fixed layer and the fixed portion is more sufficiently ensured, so that the movable layer can be supported more stably.

[0015] The Fabry-Perot interference filter of the present invention may be [9] "the Fabry-Perot interference filter according to any one of the above [1] to [8], further comprising a second fixed layer laminated on the movable layer on the side opposite to the first fixed layer, and the fixed portion is bonded to the second fixed layer." According to this Fabry-Perot interference filter, not only the bonding area between the first fixed layer and the fixed portion but also the bonding area between the second fixed layer and the fixed portion is sufficiently secured, so that the movable layer can be supported more stably.

[0016] The Fabry-Perot interference filter of the present invention may be

[10] "a Fabry-Perot interference filter according to any one of the above [1] to [9], in which, in the pair of first regions adjacent to each other among the plurality of first regions and in one second region connecting the pair of first regions among the plurality of second regions, when viewed from the direction, the distance between the intersection in the extension direction of each of the pair of first regions and the one second region is greater than the distance between each of the plurality of second regions and the movable part." According to the Fabry-Perot interference filter, the bonding area between the first fixed layer and the fixed part is more sufficiently secured, so that the movable layer can be supported more stably.

[0017] The Fabry-Perot interference filter of the present invention may be

[11] "the Fabry-Perot interference filter according to any one of the above [1] to

[10] , in which, in the pair of first regions adjacent to each other among the plurality of first regions and in one second region connecting the pair of first regions among the plurality of second regions, when viewed from the direction, the distance between the intersection in the extension direction of each of the pair of first regions and the one second region is longer than the length of each of the plurality of elastic deformation portions." According to the Fabry-Perot interference filter, the bonding area between the first fixed layer and the fixed portion is more sufficiently secured, so that the movable layer can be supported more stably. Effect of the Invention

[0018] According to the present invention, it is possible to provide a Fabry-Perot interference filter in which the first reflective film can be appropriately moved relative to the second reflective film. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view of an example 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] FIG. 6 is a bottom view of a portion of the first layer shown in FIG. 5. [Figure 10] FIG. 6 is a bottom view of a portion of the first layer shown in FIG. 5. [Figure 11] 11A and 11B are plan and bottom views of a first layer of a modified Fabry-Perot interference filter. [Figure 12] FIG. 12 is a plan view of a portion of the first layer shown in FIG. [Figure 13] FIG. 12 is a plan view of a portion of the first layer shown in FIG. [Figure 14] FIG. 11 is a longitudinal sectional view of a modified Fabry-Perot interference filter. [Figure 15] FIG. 11 is a longitudinal sectional view of a modified Fabry-Perot interference filter. [Figure 16] FIG. 11 is a longitudinal sectional view of a modified Fabry-Perot interference filter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an example of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and duplicated explanations will be omitted. [Fabry-Perot interference filter configuration]

[0021] As shown in FIG. 1, FIG. 2, FIG. 3, and FIG. 4, the Fabry-Perot interference filter 1 includes a first layer (movable layer) 10, a second layer (first fixed layer) 20, a third layer (second fixed 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 (first direction) in which the first reflection film 50 and the second reflection film 60 face each other 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 mentioned, it means one side in the Z-axis direction, and when "the other side" is simply mentioned, it means the other side in the Z-axis direction. Furthermore, when the term "thickness" is simply mentioned, it means the thickness in the Z-axis direction.

[0022] 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". In the following description, the side closer to the straight line L is the inside, and the side farther from the straight line L is the outside. 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] The semiconductor layer 12 is bonded to each of the light transmitting member 14 and the support member 15. 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 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.

[0028] The electrode unit 16 surrounds the light transmitting region 1a when viewed from the Z-axis direction. The electrode unit 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. That is, the electrode unit 16 is joined to the light transmitting member 14. When viewed from the Z-axis direction, the outer edge of the electrode unit 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 unit 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 unit 16 is formed in a circular frame shape with the straight line L as the center line. The inner diameter of the electrode unit 16 is, for example, about 3 to 5 mm. The outer diameter of the electrode unit 16 is, for example, about 4 to 6 mm. The thickness of the electrode unit 16 is, for example, about 30 μm. In the Fabry-Perot interference filter 1, the electrode unit 16 is a first electrode 19 for generating an electrostatic force. That is, the first layer 10 includes a first electrode 19. In the Fabry-Perot interference filter 1, the outer edge of the electrode portion 16 is located outside the outer edge of the light transmitting member 14, so the entire electrode portion 16 is not joined to the light transmitting member 14. In other words, it is sufficient that the electrode portion 16 includes a region joined to the light transmitting member 14.

[0029] 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 bonded to the surface 15a on one side of the support member 15. That is, the support 17 is bonded to 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. In the Fabry-Perot interference filter 1, the inner edge of the support portion 17 is located inside the inner edge of the support member 15, and therefore the entire support portion 17 is not joined to the support member 15. In other words, it is sufficient that the support portion 17 includes a region joined to the support member 15.

[0030] 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 elastic deformation parts 18 adjacent to each other in the circumferential direction. 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.

[0031] 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.

[0032] 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.

[0033] In the first layer 10 configured as above, the movable portion 10a is configured by the light transmitting member 14 and the electrode portion 16, and the fixed portion 10b is configured by the support member 15 and the support portion 17. The movable portion 10a is disposed inside the frame-shaped fixed portion 10b and overlaps with the light transmitting region 1a. In the first layer 10, the movable portion 10a is movable in the Z-axis direction by deformation of a plurality of elastic deformation portions 18 connecting the fixed portion 10b and the movable portion 10a.

[0034] 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 reflection film 50 is provided on the movable portion 10a. The first reflection film 50 is movable in the Z-axis direction together with the movable portion 10a. That is, the first layer 10 supports the first reflection film 50 so that it can move in the Z-axis direction. 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.

[0035] 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 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.

[0036] The second substrate 21 constitutes a part of the light transmitting 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 the surface opposite to the first layer 10, and the surface 21b is the surface on the first layer 10 side. The surface 21b of the second substrate 21 is bonded 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. That is, the fixing portion 10b of the first layer 10 is bonded to the second layer 20. 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 substantially coincides with the outer edge of the support portion 17, except for a notch 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 joined together by airtight bonding such as room temperature bonding, plasma activated bonding, or anodic bonding.

[0037] 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.

[0038] The second electrodes 22 are disposed on the surface 21b of the second substrate 21. That is, the second layer 20 supports the second electrodes 22. 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-like 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 a plurality of second electrodes 22 are arranged along the 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.

[0039] 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).

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 4 and 7, the third layer 30 is laminated on the first layer 10 on the other side of the first layer 10. That is, the third layer 30 is laminated on the first layer 10 on the side opposite to the second layer 20. 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.

[0047] 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 bonded to the surface 15b on the other side of the support member 15. That is, the fixing portion 10b of the first layer 10 is bonded to the third layer 30. 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, for example, 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, metal diffusion bonding, or the like.

[0048] 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.

[0049] 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 second reflection film 60 faces the first reflection film 50 through a space in the light transmission region 1a. 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 configured, 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 reflective 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.

[0050] 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.

[0051] 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.

[0052] 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. [First layer configuration]

[0053] As shown in FIG. 9, each elastic deformation portion 18 has a first boundary portion 181 and a second boundary portion 182. The first boundary portion 181 is an end portion of each elastic deformation portion 18 on the electrode portion 16 side. The second boundary portion 182 is an end portion of each elastic deformation portion 18 on the support portion 17 side. The first boundary portion 181 of each elastic deformation portion 18 is spaced apart from the light transmitting member 14. The first boundary portion 181 of each elastic deformation portion 18 is not bonded to the light transmitting member 14 and floats in space. In the Fabry-Perot interference filter 1, when viewed from the Z-axis direction, the first boundary portion 181 of each elastic deformation portion 18 does not overlap with the light transmitting member 14. The second boundary portion 182 of each elastic deformation portion 18 is spaced apart from the support member 15. The second boundary portion 182 of each elastic deformation portion 18 is not bonded to the support member 15 and floats in space. In the Fabry-Perot interference filter 1, the second boundary portion 182 of each elastic deformation portion 18 does not overlap with the support member 15 when viewed from the Z-axis direction.

[0054] Each elastic deformation portion 18 is a portion (part to be elastically deformed) designed to elastically deform when the electrode portion 16 moves in the Z-axis direction relative to the support portion 17 in a state in which the semiconductor layer 12 exists alone. In the Fabry-Perot interference filter 1, the width of the elastic deformation portion 18 (the width in a direction perpendicular to the direction in which the first boundary portion 181 and the second boundary portion 182 are arranged when viewed from the Z-axis direction) and the thickness of the elastic deformation portion 18 (the thickness in the Z-axis direction) are each substantially constant. In the Fabry-Perot interference filter 1, the cross-sectional shape of the elastic deformation portion 18 (the cross-sectional shape perpendicular to the extension direction of the elastic deformation portion 18) is substantially constant. Note that "substantially constant" means that it is within the range of manufacturing error with respect to the design value (reference value). As an example, when the design value of the width of the elastic deformation portion 18 is a value of 50 to 500 μm, the manufacturing error is ±5 μm, and when the design value of the thickness of the elastic deformation portion 18 is a value of 20 to 50 μm, the manufacturing error is ±1 μm.

[0055] The outer edge 160 of the electrode section 16 when viewed from the Z-axis direction includes a pair of first parts 161 and a pair of second parts 162. The pair of first parts 161 are parts extending from the first boundary part 181 to both sides (both sides in the circumferential direction) of the first boundary part 181 with respect to each elastic deformation part 18. That is, the pair of first parts 161 are parts extending along the outer edge 140 of the surface 14a of the light transmitting member 14 on both sides of the first boundary part 181. The pair of first parts 161 correspond to bottom parts of a pair of cutout parts 16c (see (a) of FIG. 5) that open outward on both sides (both sides in the circumferential direction) of one end of each elastic deformation part 18. The pair of second parts 162 are parts extending from the pair of first parts 161 to both sides (both sides in the circumferential direction) of the pair of first parts 161 with respect to each elastic deformation part 18. That is, the pair of second portions 162 are portions extending along the outer edge 140 of the surface 14a of the light transmitting member 14 on both sides of the pair of first portions 161. The surface 14a of the light transmitting member 14 is a bonding surface including a bonding region with the electrode portion 16 (see FIG. 4), and is a flat surface including a bonding region with the electrode portion 16. In the Fabry-Perot interference filter 1, the surface 14a is a flat surface perpendicular to the Z-axis direction.

[0056] The pair of first portions 161 and the pair of second portions 162 are located outside the outer edge 140 of the surface 14a (i.e., outside the surface 14a) when viewed from the Z-axis direction. In the Fabry-Perot interference filter 1, the entire outer edge 160 of the electrode portion 16 is located outside the outer edge 140 of the surface 14a (i.e., outside the surface 14a) when viewed from the Z-axis direction. When viewed from the Z-axis direction, the distance between the outer edge 140 of the surface 14a and each of the first portions 161 is smaller than the distance between the outer edge 140 of the surface 14a and each of the second portions 162.

[0057] A pair of corners C1 formed by the electrode portion 16 and each elastic deformation portion 18 have a continuous curvature. That is, the electrode portion 16 and each elastic deformation portion 18 are smoothly connected via the rounded chamfered surface formed at each corner C1. A pair of corners C2 formed by the support portion 17 and each elastic deformation portion 18 have a continuous curvature. That is, the support portion 17 and each elastic deformation portion 18 are smoothly connected via the rounded chamfered surface formed at each corner C2.

[0058] As shown in FIG. 5, the inner side surface Sb of the fixed portion 10b includes a plurality of first regions R1 and a plurality of second regions R2. The plurality of first regions R1 form a polygon P when viewed from the Z-axis direction, and each of the first regions R1 extends linearly as a part of each side of the polygon P. That is, the polygon P is a virtual polygon formed by extending each of the first regions R1. In the Fabry-Perot interference filter 1, the side surface Sb is an inner side surface of the support portion 17 of the semiconductor layer 12, and the polygon P is a quadrangle having a pair of sides perpendicular to the X-axis direction and a pair of sides perpendicular to the Y-axis direction. Each of the first regions R1 is connected to each of the elastic deformation portions 18. In the Fabry-Perot interference filter 1, each of the elastic deformation portions 18 is connected to each of the first regions R1 at the midpoint of the side of the corresponding polygon P. That is, each first region R1 is a region of the inner side surface Sb of the fixed portion 10b that extends linearly when viewed from the Z-axis direction and includes a portion where each elastic deformation portion 18 is connected. Each second region R2 connects a pair of adjacent first regions R1 among the multiple first regions R1. Each second region R2 corresponds to an inner chamfered surface for the pair of adjacent first regions R1. Each second region R2 extends in an outwardly convex arc shape when viewed from the Z-axis direction.

[0059] The outer side surface Sa of the movable part 10a includes a plurality of third regions R3. Each of the third regions R3 faces each of the second regions R2 via a space. In the Fabry-Perot interference filter 1, the side surface Sa is an outer side surface of the electrode portion 16 of the semiconductor layer 12. Each of the third regions R3 extends in an outwardly convex arc shape when viewed from the Z-axis direction.

[0060] As shown in FIG. 10, the distance D2 between each second region R2 and the movable part 10a is greater than the distance D1 between each first region R1 and the movable part 10a. In the Fabry-Perot interference filter 1, the distance D2 between each second region R2 and the movable part 10a is the distance between the second region R2 and the third region R3 facing each other. When viewed from the Z-axis direction, the length L1 of each first region R1 is greater than the length L2 of each second region R2. When viewed from the Z-axis direction, the length L1 of each first region R1 is greater than the length L3 of each elastic deformation portion 18. When viewed from the Z-axis direction, the length L2 of each second region R2 is greater than the width W of each elastic deformation portion 18. When viewed from the Z-axis direction, the length L2 of each second region R2 is greater than the length L3 of each elastic deformation portion 18. When viewed from the Z-axis direction, the length L2 of each second region R2 is greater than the distance D2 between each second region R2 and the movable part 10a. In a pair of adjacent first regions R1 and a second region R2 connecting the pair of first regions R1, when viewed from the Z-axis direction, a distance D3 between an intersection A in the extension direction of each of the pair of first regions R1 and the second region R2 is greater than a distance D2 between each second region R2 and the movable portion 10a. The distance D3 is greater than a length L3 of each elastic deformation portion 18. The intersection A corresponds to a vertex of the polygon P.

[0061] In addition, when the distance between each first region R1 and the movable portion 10a changes, the distance D1 means the minimum value of the distance between each first region R1 and the movable portion 10a. When the distance between each second region R2 and the movable portion 10a changes, the distance D2 means the minimum value of the distance between each second region R2 and the movable portion 10a. The length L3 of each elastic deformation portion 18 means the length of each elastic deformation portion 18 in a direction parallel to the direction in which the first boundary portion 181 and the second boundary portion 182 are arranged. The width W of each elastic deformation portion 18 means the width of each elastic deformation portion 18 in a direction perpendicular to the direction in which the first boundary portion 181 and the second boundary portion 182 are arranged when viewed from the Z-axis direction. [Action and Effects]

[0062] In the Fabry-Perot interference filter 1, the elastic deformation parts 18 are connected to the first regions R1 extending linearly on the inner side surface Sb of the fixed part 10b. This makes it possible to suppress stress concentration on the second boundary portion 182 of each elastic deformation part 18, compared to, for example, a case in which each elastic deformation part 18 is connected to each region extending in an arc shape on the inner side surface Sb of the fixed part 10b. In addition, even if the joining position of the fixed part 10b to the second layer 20 is shifted during the manufacture of the Fabry-Perot interference filter 1, it is possible to suppress the effect on the characteristics of each elastic deformation part 18. Furthermore, in the Fabry-Perot interference filter 1, each second region R2 connects a pair of adjacent first regions R1 on the inner side surface Sb of the fixed part 10b, and the distance D2 between each second region R2 and the movable part 10a is greater than the distance D1 between each first region R1 and the movable part 10a. This ensures a sufficient bonding area between the second layer 20 and the fixed portion 10b to stably support the first layer 10, while ensuring a sufficient gap between each second region R2 and the movable portion 10a to smoothly move the movable portion 10a. As described above, the Fabry-Perot interference filter 1 allows the first reflective film 50 to move appropriately relative to the second reflective film 60.

[0063] For example, in a configuration in which the elastic deformation portion 18 is connected to a region of the inner side surface Sb of the fixed portion 10b that extends in an arc shape, the characteristics of the elastic deformation portion 18 are likely to change if the joining position of the support member 15 to the support portion 17 is shifted in a direction perpendicular to the extension direction of the elastic deformation portion 18. In contrast, in a configuration in which the elastic deformation portion 18 is connected to a region of the inner side surface Sb of the fixed portion 10b that extends in a straight line, as in the Fabry-Perot interference filter 1, the characteristics of the elastic deformation portion 18 are unlikely to change even if the joining position of the support member 15 to the support portion 17 is shifted in a direction perpendicular to the extension direction of the elastic deformation portion 18.

[0064] Furthermore, for example, when the space in which the movable part 10a moves in the Z-axis direction is an airtight space filled with gas, or when the space in which the movable part 10a moves in the Z-axis direction is a non-airtight space in which air is present, if a sufficient gap is secured between each second region R2 and the movable part 10a as in the Fabry-Perot interference filter 1, the gas or air easily passes through the gap as the movable part 10a moves. In other words, the gas or air is unlikely to become a resistance to the movement of the movable part 10a.

[0065] In the Fabry-Perot interference filter 1, each second region R2 extends in an outwardly convex arc shape when viewed from the Z-axis direction, which ensures a sufficient gap between each second region R2 and the movable part 10a, allowing the movable part 10a to move more smoothly.

[0066] In the Fabry-Perot interference filter 1, the third regions R3 facing the second regions R2 of the side surface Sa of the movable portion 10a extend in an outwardly convex arc shape when viewed from the Z-axis direction. This makes the gap between each second region R2 and the movable portion 10a uniform throughout the second region R2, allowing the first reflection film 50 to move stably. In addition, if the gap between each second region R2 and the movable portion 10a is uniform throughout the second region R2, it is easy to obtain a predetermined shape when, for example, the electrode portion 16, the support portion 17, and the multiple elastic deformation portions 18 are integrally formed by etching a silicon substrate.

[0067] In the Fabry-Perot interference filter 1, when viewed from the Z-axis direction, the length L1 of each first region R1 is greater than the length L2 of each second region R2. This ensures that the length of each linearly extending first region R1 is sufficient, so that even if the joining position of the fixed portion 10b relative to the second layer 20 is shifted during the manufacture of the Fabry-Perot interference filter 1, it is possible to reliably suppress any influence on the characteristics of each elastic deformation portion 18. In addition, a more sufficient gap is ensured between each second region R2 and the movable portion 10a, so that the movable portion 10a can be moved more smoothly.

[0068] In the Fabry-Perot interference filter 1, when viewed from the Z-axis direction, the length L1 of each first region R1 is greater than the length L3 of each elastic deformation portion 18. This ensures that the length of each linearly extending first region R1 is sufficient, so that even if the joining position of the fixed portion 10b relative to the second layer 20 is shifted during the manufacture of the Fabry-Perot interference filter 1, it is possible to reliably suppress any influence on the characteristics of each elastic deformation portion 18. In addition, a more sufficient gap is ensured between each second region R2 and the movable portion 10a, so that the movable portion 10a can be moved more smoothly.

[0069] In the Fabry-Perot interference filter 1, when viewed from the Z-axis direction, the length L2 of each second region R2 is greater than the width W of each elastic deformation portion 18. This ensures a more sufficient bonding area between the second layer 20 and the fixed portion 10b, thereby making it possible to support the first layer 10 more stably.

[0070] In the Fabry-Perot interference filter 1, when viewed from the Z-axis direction, the length L2 of each second region R2 is greater than the length L3 of each elastic deformation portion 18. This ensures a more sufficient bonding area between the second layer 20 and the fixed portion 10b, thereby making it possible to support the first layer 10 more stably.

[0071] In the Fabry-Perot interference filter 1, when viewed from the Z-axis direction, the length L2 of each second region R2 is greater than the distance D2 between each second region R2 and the movable portion 10a. This ensures a sufficient bonding area between the second layer 20 and the fixed portion 10b, thereby supporting the first layer 10 more stably.

[0072] In the Fabry-Perot interference filter 1, a third layer 30 is laminated on the first layer 10 on the side opposite to the second layer 20, and the fixed portion 10b is joined to the third layer 30. This ensures a sufficient joining area between not only the second layer 20 and the fixed portion 10b but also the third layer 30 and the fixed portion 10b, so that the first layer 10 can be supported more stably.

[0073] In the Fabry-Perot interference filter 1, in a pair of adjacent first regions R1 and in one second region R2 connecting the pair of first regions R1, when viewed from the Z-axis direction, a distance D3 between the intersection A in the extension direction of each of the pair of first regions R1 and the one second region R2 is greater than a distance D2 between each second region R2 and the movable portion 10a. This ensures a more sufficient bonding area between the second layer 20 and the fixed portion 10b, thereby making it possible to support the first layer 10 more stably.

[0074] In the Fabry-Perot interference filter 1, in a pair of adjacent first regions R1 and in one second region R2 connecting the pair of first regions R1, when viewed from the Z-axis direction, a distance D3 between an intersection A in the extension direction of each of the pair of first regions R1 and the one second region R2 is greater than a length L3 of each elastic deformation portion 18. This ensures a more sufficient bonding area between the second layer 20 and the fixed portion 10b, thereby making it possible to support the first layer 10 more stably. [Configuration of the first layer of the modified Fabry-Perot interference filter]

[0075] The first layer 10 shown in Fig. 11 differs from the first layer 10 shown in Fig. 5 mainly in that, when viewed from the Z-axis direction, the outer edge of the electrode section 16 is located inside the outer edge of the light transmitting member 14, and the inner edge of the support section 17 is located outside the inner edge of the support member 15. In the first layer 10 shown in Fig. 11, similarly to the first layer 10 shown in Fig. 5, the light transmitting member 14 and the electrode section 16 form a movable section 10a, and the support member 15 and the support section 17 form a fixed section 10b. The first layer 10 shown in Fig. 11 will be described below with reference to Figs. 11, 12, and 13.

[0076] As shown in FIG. 12, each elastic deformation portion 18 has a first boundary portion 181 and a second boundary portion 182. The first boundary portion 181 is an end portion of each elastic deformation portion 18 on the electrode portion 16 side. The second boundary portion 182 is an end portion of each elastic deformation portion 18 on the support portion 17 side. The first boundary portion 181 of each elastic deformation portion 18 is separated from the light transmitting member 14. The first boundary portion 181 of each elastic deformation portion 18 is not bonded to the light transmitting member 14 and floats in space. In this modification, when viewed from the Z-axis direction, the first boundary portion 181 of each elastic deformation portion 18 does not overlap with the light transmitting member 14. The second boundary portion 182 of each elastic deformation portion 18 is separated from the support member 15. The second boundary portion 182 of each elastic deformation portion 18 is not bonded to the support member 15 and floats in space. In this modification, the second boundary portion 182 of each elastic deformation portion 18 does not overlap with the support member 15 when viewed from the Z-axis direction.

[0077] The electrode portion 16 includes a plurality of first connection portions 163. Each of the first connection portions 163 is connected to a first boundary portion 181 of each of the elastic deformation portions 18 and is joined to the light transmitting member 14. The support portion 17 includes a plurality of second connection portions 173. Each of the second connection portions 173 is connected to a second boundary portion 182 of each of the elastic deformation portions 18 and is joined to the support member 15.

[0078] One elastic deformation portion 18, and one first connection portion 163 and one second connection portion 173 connected by the one elastic deformation portion 18 are configured as one elastic deformation portion 180 in the semiconductor layer 12. That is, the semiconductor layer 12 includes a plurality of elastic deformation portions 180 corresponding to the plurality of elastic deformation portions 18. Each elastic deformation portion 180 is a portion designed to elastically deform when the electrode portion 16 moves in the Z-axis direction relative to the support portion 17 in a state in which the semiconductor layer 12 exists alone.

[0079] In this modification, the width (width in a direction perpendicular to the direction in which the first boundary portion 181 and the second boundary portion 182 are arranged when viewed from the Z-axis direction) and the thickness (thickness in the Z-axis direction) of the elastic deformation portion 18 are each substantially constant. In this modification, the cross-sectional shape (cross-sectional shape perpendicular to the extension direction of the elastic deformation portion 18) of the elastic deformation portion 18 is substantially constant.

[0080] In this modification, the first connection portion 163 has a cross-sectional shape (cross-sectional shape perpendicular to the extending direction of the elastic deformation portion 18) substantially identical to that of the first boundary portion 181 of the elastic deformation portion 18. That is, the first connection portion 163 has a width (width in a direction perpendicular to the direction in which the first boundary portion 181 and the second boundary portion 182 are arranged when viewed from the Z-axis direction) and a thickness (thickness in the Z-axis direction) substantially identical to that of the first boundary portion 181 of the elastic deformation portion 18. The second connection portion 173 has a cross-sectional shape (cross-sectional shape perpendicular to the extending direction of the elastic deformation portion 18) substantially identical to that of the second boundary portion 182 of the elastic deformation portion 18. That is, the second connection portion 173 has a width (width in a direction perpendicular to the direction in which the first boundary portion 181 and the second boundary portion 182 are arranged when viewed from the Z-axis direction) and a thickness (thickness in the Z-axis direction) substantially identical to that of the second boundary portion 182 of the elastic deformation portion 18. However, the first connection portion 163 may not have substantially the same thickness as the first boundary portion 181 of the elastic deformation portion 18, so long as it has substantially the same width as the first boundary portion 181 of the elastic deformation portion 18. Similarly, the second connection portion 173 may not have substantially the same thickness as the second boundary portion 182 of the elastic deformation portion 18, so long as it has substantially the same width as the second boundary portion 182 of the elastic deformation portion 18. Note that "substantially the same" means that it falls within the range of manufacturing error with respect to the design value (reference value).

[0081] The outer edge 160 of the electrode section 16 when viewed from the Z-axis direction includes a pair of first parts 161 and a pair of second parts 162. The pair of first parts 161 are parts extending from the first connection part 163 to both sides (both sides in the circumferential direction) of the first connection part 163 with respect to each elastic deformation part 18. That is, the pair of first parts 161 are parts extending along the outer edge 140 of the surface 14a of the light transmitting member 14 on both sides of the first connection part 163. The pair of second parts 162 are parts extending from the pair of first parts 161 to both sides (both sides in the circumferential direction) of the pair of first parts 161 with respect to each elastic deformation part 18. That is, the pair of second parts 162 are parts extending along the outer edge 140 of the surface 14a of the light transmitting member 14 on both sides of the pair of first parts 161. The surface 14a of the light transmitting member 14 is a first bonding surface including a bonding area with the electrode portion 16 (see FIG. 4), and is a flat surface including a bonding area with the electrode portion 16. In this modification, the surface 14a is a flat surface perpendicular to the Z-axis direction.

[0082] The pair of first portions 161 and the pair of second portions 162 are located inside the outer edge 140 of the surface 14a (i.e., within the surface 14a) when viewed from the Z axis direction. In this modification, the entire outer edge 160 of the electrode portion 16 is located inside the outer edge 140 of the surface 14a (i.e., within the surface 14a) when viewed from the Z axis direction. When viewed from the Z axis direction, the distance between the outer edge 140 of the surface 14a and each of the first portions 161 is greater than the distance between the outer edge 140 of the surface 14a and each of the second portions 162.

[0083] The outer edge 170 of the support portion 17 when viewed from the Z-axis direction includes a pair of third portions 171 and a pair of fourth portions 172. The pair of third portions 171 are portions extending from the second connection portion 173 to both sides (both sides in the circumferential direction) of the second connection portion 173 with respect to each elastic deformation portion 18. That is, the pair of third portions 171 are portions extending along the outer edge 150 of the surface 15a of the support member 15 on both sides of the second connection portion 173. The pair of fourth portions 172 are portions extending from the pair of third portions 171 to both sides (both sides in the circumferential direction) of the pair of third portions 171 with respect to each elastic deformation portion 18. That is, the pair of fourth portions 172 are portions extending along the outer edge 150 of the surface 15a of the support member 15 on both sides of the pair of third portions 171. Surface 15a of supporting member 15 is a second bonding surface including a bonding area with supporting part 17 (see FIG. 4), and is a flat surface including a bonding area with supporting part 17. In this modification, surface 15a is a flat surface perpendicular to the Z-axis direction.

[0084] The pair of third portions 171 and the pair of fourth portions 172 are located inside the outer edge 150 of the surface 15a (i.e., within the surface 15a) when viewed from the Z axis direction. In this modification, the entire outer edge 170 of the support portion 17 is located inside the outer edge 150 of the surface 15a (i.e., within the surface 15a) when viewed from the Z axis direction. When viewed from the Z axis direction, the distance between the outer edge 150 of the surface 15a and each of the third portions 171 is greater than the distance between the outer edge 150 of the surface 15a and each of the fourth portions 172.

[0085] For each elastic deformation portion 18, a pair of corners C1 formed on both sides of the first connection portion 163 have a continuous curvature. That is, each elastic deformation portion 180 is smoothly connected to the electrode portion 16 via the rounded chamfered surface formed at each corner C1. For each elastic deformation portion 18, a pair of corners C2 formed on both sides of the second connection portion 173 have a continuous curvature. That is, each elastic deformation portion 180 is smoothly connected to the support portion 17 via the rounded chamfered surface formed at each corner C2.

[0086] As shown in FIG. 11, the inner side surface Sb of the fixing portion 10b includes a plurality of first regions R1 and a plurality of second regions R2. The plurality of first regions R1 form a polygon P when viewed from the Z-axis direction, and each of the first regions R1 extends linearly as a part of each side of the polygon P. In this modification, the side surface Sb is an inner side surface of the support member 15, and the polygon P is a quadrangle having a pair of sides perpendicular to the X-axis direction and a pair of sides perpendicular to the Y-axis direction. Each of the first regions R1 is connected to each of the elastic deformation portions 18. In this modification, each of the elastic deformation portions 18 is connected to each of the first regions R1 at the position of the midpoint of the side of the corresponding polygon P. In this modification, each of the elastic deformation portions 18 is connected to each of the first regions R1 so that a corner is formed by the first region R1 and the surface on one side of the elastic deformation portion 18. Each of the second regions R2 connects a pair of adjacent first regions R1 among the plurality of first regions R1. Each of the second regions R2 corresponds to an inner chamfered surface of a pair of adjacent first regions R1. Each of the second regions R2 extends in an outwardly convex arc shape when viewed from the Z-axis direction.

[0087] The outer side surface Sa of the movable part 10a includes a plurality of third regions R3. Each of the third regions R3 faces each of the second regions R2 via a space. In this modification, the side surface Sa is an outer side surface of the light transmitting member 14. Each of the third regions R3 extends in an outwardly convex arc shape when viewed from the Z-axis direction.

[0088] As shown in FIG. 13, the distance D2 between each second region R2 and the movable part 10a is greater than the distance D1 between each first region R1 and the movable part 10a. In this modification, the distance D2 between each second region R2 and the movable part 10a is the distance between the second region R2 and the third region R3 facing each other. When viewed from the Z-axis direction, the length L1 of each first region R1 is greater than the length L2 of each second region R2. When viewed from the Z-axis direction, the length L1 of each first region R1 is greater than the length L3 of each elastic deformation portion 18. When viewed from the Z-axis direction, the length L2 of each second region R2 is greater than the length L3 of each elastic deformation portion 18. When viewed from the Z-axis direction, the length L2 of each second region R2 is greater than the width W of each elastic deformation portion 18. When viewed from the Z-axis direction, the length L2 of each second region R2 is greater than the distance D2 between each second region R2 and the movable part 10a. In a pair of adjacent first regions R1 and a second region R2 connecting the pair of first regions R1, a distance D3 between the intersection A in the extension direction of each of the pair of first regions R1 and the second region R2 is greater than a distance D2 between each second region R2 and the movable portion 10a when viewed from the Z-axis direction. The distance D3 is greater than the length L3 of each elastic deformation portion 18.

[0089] According to the Fabry-Perot interference filter 1 having the first layer 10 shown in Figure 11, the first reflective film 50 can be appropriately moved relative to the second reflective film 60 for the same reasons as those of the Fabry-Perot interference filter 1 having the first layer 10 shown in Figure 5. [Variations]

[0090] The present invention is not limited to the above-mentioned example and modified example. For example, the electrode unit 16 may be a portion provided with a first electrode 19 for generating an electrostatic force. As an example, as shown in FIG. 14, the first electrode 19 may be disposed on the surface of one side of the electrode unit 16. In this example, the first electrode 19 is one electrode surrounding the light-transmitting region 1a when viewed from the Z-axis direction, and faces a plurality of second electrodes 22 in the Z-axis direction through a space. Note that the electrode unit 16 may include a portion that functions as an electrode for generating an electrostatic force, or a portion provided with the first electrode 19 for generating an electrostatic force. In other words, in this specification, the electrode unit 16 is an example of a movable portion.

[0091] As shown in FIG. 15, the first reflection film 50 may be disposed on the surface 14a of the light transmitting member 14, and in that case, the second reflection film 60 may be disposed on the surface 21b of the second substrate 21 of the second layer 20. In this example, the first reflection film 50 is surrounded by the electrode portion 16 on the surface 14a of the light transmitting member 14, and the second reflection film 60 is surrounded by a plurality of second electrodes 22 on the surface 21b of the second substrate 21. In the Fabry-Perot interference filter 1 shown in FIG. 15, the second layer 20 supports the second reflection film 60 and the plurality of second electrodes 22. In other words, the second layer 20 corresponds to a "first fixed layer supporting at least one of the second reflection film and the second electrode."

[0092] As shown in FIG. 16, the Fabry-Perot interference filter 1 may not include the second layer 20. In this example, the second electrodes 22 are arranged on the surface 31a of the third substrate 31 so as to surround the second reflection film 60 when viewed from the Z-axis direction, and the third electrodes 24 are arranged on the surface 31b of the third substrate 31 so as to surround the light-transmitting region 1a when viewed from the Z-axis direction. The second electrodes 22 and the third electrodes 24 are electrically connected to each other via the through electrodes 26 provided in the third substrate 31. The metal pad 13 is arranged on the surface 31b of the third substrate 31. The first electrode 19 and the metal pad 13 are electrically connected to each other via the semiconductor layer 12, the through electrodes 29 provided in the first substrate 11, the frame 41 arranged between the first substrate 11 and the third substrate 31, and the through electrodes 29 provided in the third substrate 31. 16, the third layer 30 supports the second reflective film 60 and the multiple second electrodes 22. In other words, the third layer 30 corresponds to a "first fixed layer supporting at least one of the second reflective film and the second electrodes."

[0093] The third layer 30 may be laminated on the first layer 10 without a separate member therebetween, or may be laminated on the first layer 10 with a separate member therebetween. The second layer 20 may be laminated on the first layer 10 without a separate member therebetween, or may be laminated on the first layer 10 with a separate member therebetween. [Explanation of symbols]

[0094] 1...Fabry-Perot interference filter, 1a...light transmitting region, 10...first layer (movable layer), 10a...movable portion, 10b...fixed portion, 18...elastic deformation portion, 19...first electrode, 20...second layer (first fixed layer), 22...second electrode, 30...third layer (second fixed layer), 50...first reflective film, 60...second reflective film, A...intersection, D1, D2, D3...distance, L1, L2, L3...length, P...polygon, R1...first region, R2...second region, R3...third region, Sb, Sb...side, W...width.

Claims

1. A first reflective film; a second reflective film facing the first reflective film across a space in the light transmitting region; a movable layer including a first electrode and supporting the first reflective film so as to be movable in a direction in which the first reflective film and the second reflective film face each other; a second electrode facing the first electrode across a space in the direction; a first fixed layer that is stacked on the movable layer and supports at least one of the second reflective film and the second electrode; The movable layer is a frame-shaped fixing portion joined to the first fixing layer; a movable portion disposed inside the fixed portion and provided with the first reflective film; a plurality of elastic deformation portions connecting the fixed portion and the movable portion, The inner side surface of the fixing portion is a plurality of first regions each extending linearly when viewed from the direction, and to which the plurality of elastic deformation portions are connected; a plurality of second regions each connecting a pair of adjacent first regions among the plurality of first regions, A Fabry-Perot interference filter, wherein a distance between each of the plurality of second regions and the movable portion is greater than a distance between each of the plurality of first regions and the movable portion.

2. The Fabry-Perot interference filter according to claim 1 , wherein each of the second regions extends in an outwardly convex arc shape when viewed from the direction.

3. 3. The Fabry-Perot interference filter of claim 2, wherein each of a plurality of third regions on the side surface of the movable portion that faces at least the plurality of second regions extends in an outwardly convex arc shape when viewed from the direction.

4. The Fabry-Perot interference filter according to claim 1 , wherein, when viewed from the direction, a length of each of the plurality of first regions is greater than a length of each of the plurality of second regions.

5. The Fabry-Perot interference filter according to claim 1 , wherein when viewed from the direction, a length of each of the plurality of first regions is greater than a length of each of the plurality of elastic deformation portions.

6. The Fabry-Perot interference filter according to claim 1 , wherein when viewed from the direction, a length of each of the second regions is greater than a width of each of the elastic deformation portions.

7. The Fabry-Perot interference filter according to claim 1 , wherein when viewed from the direction, a length of each of the second regions is greater than a length of each of the elastic deformation portions.

8. The Fabry-Perot interference filter according to claim 1 , wherein when viewed from the direction, a length of each of the second regions is greater than the distance between each of the second regions and the movable portion.

9. a second fixed layer laminated on the movable layer on the side opposite to the first fixed layer; The Fabry-Perot interference filter according to claim 1 , wherein the fixing portion is bonded to the second fixing layer.

10. 2. The Fabry-Perot interference filter of claim 1, wherein in a pair of adjacent first regions among the plurality of first regions, and in a second region among the plurality of second regions connecting the pair of first regions, when viewed from the direction, the distance between an intersection in the extension direction of each of the pair of first regions and the one second region is greater than the distance between each of the plurality of second regions and the movable part.

11. 2. The Fabry-Perot interference filter of claim 1, wherein in a pair of adjacent first regions among the plurality of first regions, and in a second region among the plurality of second regions connecting the pair of first regions, when viewed from the direction, the distance between an intersection in the extension direction of each of the pair of first regions and the one second region is greater than the length of each of the plurality of elastic deformation portions.

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