Fabry-perot interference filter

Abstract

This Fabry-Perot interference filter comprises a first reflective film, a second reflective film, a movable layer that supports the first reflective film, a fixed layer that supports the second reflective film, and a protrusion. When the protrusion is disposed on a movable surface, the first reflective film covers the entirety of the protrusion, the outer edge of the first reflective film is positioned inward relative to a bonded region, and the portion of the first reflective film positioned on the protrusion faces a fixed surface or the second reflective film. When the protrusion is disposed on the fixed surface, the second reflective film covers the entirety of the protrusion, the outer edge of the second reflective film is positioned inward relative to the bonded region, and the portion of the second reflective film positioned on the protrusion faces the movable surface or the first reflective film.

Description

Fabry-Perot interference filter

[0001] The present disclosure relates to Fabry-Perot interference filters.

[0002] A Fabry-Perot interference filter is known that includes a first substrate, a second substrate stacked on the first substrate, a first reflective film arranged on a first surface of the first substrate facing the second substrate, a second reflective film arranged on a second surface of the second substrate facing the first substrate across a space, a plurality of first convex portions arranged on the first surface so as to surround the first reflective film, and a plurality of second convex portions arranged on the second surface so as to surround the second reflective film and face the plurality of first convex portions across a space, and in which a portion of the first substrate that supports the first reflective film and the plurality of first convex portions 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).

[0003] JP 2014-164069 A

[0004] In the Fabry-Perot interference filter described above, the distance between the multiple first convex portions and the multiple second convex portions is smaller than the distance between the first reflective film and the second reflective film. Therefore, when the first reflective film approaches the second reflective film, the multiple first convex portions come into contact with the multiple second convex portions before the first reflective film comes into surface contact with the second reflective film. This prevents sticking between the first reflective film and the second reflective film (a phenomenon in which the first reflective film and the second reflective film stick to each other due to intermolecular forces, etc.).

[0005] However, in the above-described Fabry-Perot interference filter, there is a risk that the multiple first protrusions may fall off from the first surface of the first substrate due to a difference in the thermal expansion coefficient between the first substrate and each first protrusion, the action of an external force on the Fabry-Perot interference filter, etc. Similarly, there is a risk that the multiple second protrusions may fall off from the second surface of the second substrate due to a difference in the thermal expansion coefficient between the second substrate and each second protrusion, the action of an external force on the Fabry-Perot interference filter, etc. If such falling off occurs, sticking of the first reflective film and the second reflective film is likely to occur.

[0006] An object of the present disclosure is to provide a Fabry-Perot interference filter that can stably suppress the occurrence of sticking between a first reflective film and a second reflective film.

[0007] A Fabry-Perot interference filter according to one aspect of the present disclosure includes: [1] "a first reflective film; a second reflective film facing the first reflective film across a space in a light-transmitting region; a movable layer including a first electrode and supporting the first reflective film in a movable section movable in a first direction in which the first reflective film and the second reflective film face each other; a fixed layer bonded to the movable layer in a bonding region surrounding the light-transmitting region when viewed from the first direction and supporting the second reflective film; a second electrode facing the first electrode across a space in the first direction; and a convex portion disposed on a movable surface of the movable section facing the fixed layer or on a fixed surface of the fixed layer facing the movable section, the first reflective film covers the entire convex portion on the movable surface, the outer edge of the first reflective film is located inside the bonding region when viewed from the first direction, and the portion of the first reflective film located on the convex portion faces the fixed surface or the second reflective film in the first direction; and when the convex portion is arranged on the fixed surface, the second reflective film covers the entire convex portion on the fixed surface, the outer edge of the second reflective film is located inside the bonding region when viewed from the first direction, and the portion of the second reflective film located on the convex portion faces the movable surface or the first reflective film in the first direction.

[0008] In the Fabry-Perot interference filter described in [1] above, a convex portion is arranged on the movable surface of the movable portion or on the fixed surface of the fixed layer. When the convex portion is arranged on the movable surface, the first reflective film covers the entire convex portion on the movable surface, and the portion of the first reflective film located on the convex portion faces the fixed surface or the second reflective film in the first direction. When the convex portion is arranged on the fixed surface, the second reflective film covers the entire convex portion on the fixed surface, and the portion of the second reflective film located on the convex portion faces the movable surface or the first reflective film in the first direction. As a result, when the convex portion is arranged on the movable surface, when the first reflective film approaches the second reflective film, the portion of the first reflective film located on the convex portion comes into contact with the fixed surface or the second reflective film before the first reflective film comes into surface contact with the second reflective film in the light-transmitting region, thereby suppressing sticking between the first reflective film and the second reflective film. Similarly, when the convex portion is disposed on the fixed surface, as the first reflective film approaches the second reflective film, a portion of the second reflective film located on the convex portion comes into contact with the movable surface or the first reflective film before the first reflective film comes into surface contact with the second reflective film in the light-transmitting region, thereby suppressing sticking between the first reflective film and the second reflective film. Furthermore, when the convex portion is disposed on the movable surface, the first reflective film covers the entire convex portion on the movable surface, thereby suppressing detachment of the convex portion from the movable surface even if there is a difference in thermal expansion coefficient between the movable portion and the convex portion or even if an external force acts on the Fabry-Perot interference filter. Moreover, when the convex portion is disposed on the movable surface, the outer edge of the first reflective film is located inside the bonding region between the movable layer and the fixed layer, thereby suppressing deterioration, peeling, etc. of the first reflective film, and as a result, the effect of suppressing detachment of the convex portion from the movable surface is maintained. Similarly, when the convex portion is disposed on the fixed surface, the second reflective film covers the entire convex portion on the fixed surface, so that the convex portion is prevented from falling off from the fixed surface even if there is a difference in thermal expansion coefficient between the fixed layer and the convex portion or even if an external force acts on the Fabry-Perot interference filter. Moreover, when the convex portion is disposed on the fixed surface, the outer edge of the second reflective film is located inside the bonding region between the movable layer and the fixed layer, so that deterioration, peeling, etc. of the second reflective film is prevented, and as a result, the effect of preventing the convex portion from falling off from the fixed surface is maintained.As described above, the Fabry-Perot interference filter described in [1] above can stably suppress the occurrence of sticking between the first reflective film and the second reflective film.

[0009] A Fabry-Perot interference filter according to one aspect of the present disclosure may be [2] "the Fabry-Perot interference filter according to the above [1], in which the convex portion is disposed on the fixed surface." According to the Fabry-Perot interference filter according to [2], the manufacturing process can be simplified compared to when the convex portion is disposed on the movable surface of the movable part.

[0010] A Fabry-Perot interference filter according to one aspect of the present disclosure may be [3] "the Fabry-Perot interference filter according to the above [1] or [2], in which the outer edge of the first reflective film and the outer edge of the second reflective film are located outside the convex portions when viewed from the first direction." According to the Fabry-Perot interference filter according to [3], a portion where the film thickness of both the first reflective film and the second reflective film is uniform can be secured widely in an area inside the convex portions. In other words, a wide light transmission area can be secured in the Fabry-Perot interference filter.

[0011] A Fabry-Perot interference filter according to one aspect of the present disclosure may be [4] "the Fabry-Perot interference filter according to [3] above, in which each of the first reflective film and the second reflective film includes a metal film." In the Fabry-Perot interference filter according to [4], it is assumed that the outer edges of the first reflective film and the second reflective film are located outside the convex portions. Therefore, a portion of one of the first reflective film and the second reflective film that is located on the convex portion comes into contact with the other of the first reflective film and the second reflective film. Therefore, according to the Fabry-Perot interference filter according to [4], for example, by bringing the metal film of the first reflective film and the metal film of the second reflective film into contact with each other, the metal films can be made to have the same potential, and unnecessary electrostatic force can be suppressed from occurring between the first reflective film and the second reflective film.

[0012] A Fabry-Perot interference filter according to one aspect of the present disclosure may be [5] "the Fabry-Perot interference filter according to any one of the above [1] to [4], wherein, when the convex portion is disposed on the movable surface, the top surface area of ​​the portion of the first reflective film located on the convex portion is smaller than the top surface area of ​​the convex portion, and when the convex portion is disposed on the fixed surface, the top surface area of ​​the portion of the second reflective film located on the convex portion is smaller than the top surface area of ​​the convex portion." In the Fabry-Perot interference filter according to [5], when the convex portion is disposed on the movable surface, when the portion of the first reflective film located on the convex portion comes into contact with the fixed layer or the second reflective film, the intermolecular force generated between the portion of the first reflective film located on the convex portion and the fixed layer or the second reflective film is reduced. Furthermore, when the convex portion is disposed on the fixed surface, when the movable portion or the first reflective film comes into contact with the portion of the second reflective film located on the convex portion, the intermolecular force generated between the portion of the second reflective film located on the convex portion and the movable portion or the first reflective film is reduced. Therefore, according to the Fabry-Perot interference filter described in [5], the movable part can be moved smoothly.

[0013] A Fabry-Perot interference filter according to one aspect of the present disclosure may be [6] "the Fabry-Perot interference filter according to any one of the above [1] to [5], wherein, when the convex portion is disposed on the movable surface, the first reflective film, in an outer edge region along the outer edge of the first reflective film, becomes thinner as it approaches the outer edge of the first reflective film; and when the convex portion is disposed on the fixed surface, the second reflective film, in an outer edge region along the outer edge of the second reflective film, becomes thinner as it approaches the outer edge of the second reflective film." In the Fabry-Perot interference filter according to [6], when the convex portion is disposed on the movable surface, the outer edge region of the first reflective film becomes even less likely to peel off from the movable surface, and when the convex portion is disposed on the fixed surface, the outer edge region of the second reflective film becomes even more unlikely to peel off from the fixed surface. Thus, the Fabry-Perot interference filter according to [6] can more stably prevent the convex portion from falling off the movable surface or the fixed surface.

[0014] A Fabry-Perot interference filter according to one aspect of the present disclosure may be [7] "the Fabry-Perot interference filter according to any one of the above [1] to [6], wherein each of the first reflective film and the second reflective film is a film formed by physical vapor deposition using a shadow mask." A film formed by physical vapor deposition using a shadow mask becomes thinner in an outer edge region along the outer edge of the film as it approaches the outer edge. Therefore, in the Fabry-Perot interference filter according to [7], the outer edge region of the first reflective film is even less likely to peel off from the movable surface, and the outer edge region of the second reflective film is even more unlikely to peel off from the fixed surface. Therefore, the Fabry-Perot interference filter according to [7] can more stably prevent the convex portions from falling off the movable surface or the fixed surface.

[0015] A Fabry-Perot interference filter according to one aspect of the present disclosure may be [8] "the Fabry-Perot interference filter according to any one of [1] to [7] above, wherein the outer edge of the first reflective film and the outer edge of the second reflective film are located inside the bonding region when viewed from the first direction, and each of the first reflective film and the second reflective film includes a film made of Ag or an Ag alloy." Although films made of Ag or an Ag alloy are prone to deterioration, in the Fabry-Perot interference filter according to [8], the outer edges of the first reflective film and the second reflective film are located inside the bonding region between the movable layer and the fixed layer. Therefore, the Fabry-Perot interference filter according to [8] can suppress deterioration, peeling, and the like of the first reflective film and the second reflective film, which include films made of Ag or an Ag alloy.

[0016] A Fabry-Perot interference filter according to one aspect of the present disclosure may be [9] "the Fabry-Perot interference filter according to any one of the above [1] to [8], wherein the convex portions are a plurality of convex portions surrounding the light transmission region when viewed from the first direction." According to the Fabry-Perot interference filter according to [9], the volume of each convex portion can be reduced, and therefore, during the manufacture of the Fabry-Perot interference filter, it is possible to prevent each convex portion from falling off from the movable surface due to a difference in thermal expansion coefficient between the movable portion and each convex portion, or to prevent each convex portion from falling off from the fixed surface due to a difference in thermal expansion coefficient between the fixed layer and each convex portion.

[0017] The Fabry-Perot interference filter according to one aspect of the present disclosure may be

[10] "the Fabry-Perot interference filter according to any one of the above [1] to [9], wherein, when the convex portion is disposed on the movable surface, a portion of the first reflective film located on the convex portion is in contact with the fixed surface or the second reflective film when no potential difference is generated between the first electrode and the second electrode, and when the convex portion is disposed on the fixed surface, a portion of the second reflective film located on the convex portion is in contact with the movable surface or the first reflective film when no potential difference is generated between the first electrode and the second electrode." The Fabry-Perot interference filter according to

[10] is configured such that a load is applied to the convex portion when no potential difference is generated between the first electrode and the second electrode. However, even with such a configuration, sticking of the first reflective film and the second reflective film can be stably suppressed.

[0018] A Fabry-Perot interference filter according to one aspect of the present disclosure may be

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

[10] , further comprising a wiring layer stacked on the movable layer on the side opposite to the fixed layer in the first direction, and the second electrode being disposed on a surface of the wiring layer facing the movable layer." According to the Fabry-Perot interference filter described in

[11] , the second electrode can be reliably supported so as to face the first electrode via a space, and an electrostatic force can be appropriately generated between the first electrode and the second electrode.

[0019] According to the present disclosure, it is possible to provide a Fabry-Perot interference filter that can stably suppress the occurrence of sticking between the first reflective film and the second reflective film.

[0020] FIG. 1 is a perspective view of a Fabry-Perot interference filter of one embodiment. FIG. 2 is an exploded perspective view of the Fabry-Perot interference filter shown in FIG. 1. FIG. 3 is an exploded perspective view of the Fabry-Perot interference filter shown in FIG. 1. FIG. 4 is a longitudinal cross-sectional view of the Fabry-Perot interference filter shown in FIG. 1. FIG. 5 is a plan view and a bottom view of the first layer shown in FIG. 1. FIG. 6 is a plan view and a bottom view of the second layer shown in FIG. 1. FIG. 7 is a plan view and a bottom view of the third layer shown in FIG. 1. FIG. 8 is a longitudinal cross-sectional view of a portion of the absorbing film shown in FIG. 1. FIG. 9 is a longitudinal cross-sectional view of a portion of the Fabry-Perot interference filter shown in FIG. 4. FIG. 10 is a longitudinal cross-sectional view of a modified Fabry-Perot interference filter. FIG. 11 is a longitudinal cross-sectional view of a modified Fabry-Perot interference filter. FIG. 12 is a longitudinal cross-sectional view of a portion of a modified Fabry-Perot interference filter.

[0021] Hereinafter, embodiments of the present disclosure 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. [Configuration of Fabry-Perot interference filter]

[0022] As shown in Figures 1, 2, 3, and 4, the Fabry-Perot interference filter 1 includes a first layer (movable layer) 10, a second layer (wiring layer) 20, a third layer (fixed layer) 30, a first reflective film 50, a second reflective film 60, an absorbing film 70, and a plurality of convex portions 80. The first reflective film 50 and the second reflective film 60 face each other across a space. In the following description, the direction in which the first reflective film 50 and the second reflective film 60 face each other (first direction) is referred to as the "Z-axis direction," a 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 and second directions) is referred to as the "Y-axis direction." Note that a simple reference to "one side" refers to one side in the Z-axis direction, and a simple reference to "the other side" refers to the other side in the Z-axis direction. Furthermore, when simply referring to "thickness," it means the thickness in the Z-axis direction.

[0023] In the Fabry-Perot interference filter 1, the region overlapping both the first reflective film 50 and the second reflective film 60 when viewed from the Z-axis direction functions as the light-transmitting region 1a. The light-transmitting region 1a is a region in which the first reflective film 50 and the second reflective film 60 function as mirrors, transmitting light according to the distance between the first reflective film 50 and the second reflective film 60. As an example, the light-transmitting region 1a is a cylindrical region with a center line that is a straight line L parallel to the Z-axis direction. 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.

[0024] 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.

[0025] The first substrate 11 includes a light-transmitting member 14 and a support member 15. The light-transmitting member 14 and the support 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 support member 15 are formed as separate bodies 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 using airtight bonding such as room-temperature bonding, plasma activated bonding, or anodic bonding. In the Fabry-Perot interference filter 1, the light-transmitting member 14 and the support member 15, which are 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 support member 15 may be made of different materials.

[0026] 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 the shape of a circular plate with the straight line L as its 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.

[0027] 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, approximately 11 mm. The thickness of the support member 15 is, for example, approximately 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, approximately 0.5 to 1.5 mm.

[0028] 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 with 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.

[0029] 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. 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 the shape of a circular frame with the straight line L as its center line. The inner diameter of the electrode unit 16 is, for example, approximately 3 to 5 mm. The outer diameter of the electrode unit 16 is, for example, approximately 4 to 6 mm. The thickness of the electrode unit 16 is, for example, approximately 30 μm. In the Fabry-Perot interference filter 1, the electrode unit 16 functions as a first electrode 19. In other words, the first layer 10 includes the first electrode 19.

[0030] The support portion 17 surrounds the electrode portion 16 when viewed from the Z-axis direction. A space is formed between the electrode portion 16 and the support portion 17. The support portion 17 is bonded to the surface 15a on one side of the support member 15. In the Fabry-Perot interference filter 1, when viewed from the Z-axis direction, the outer edge of the support portion 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 portion 17 is located inside the inner edge of the support member 15. As an example, the support portion 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 portion 17 in each of the X-axis direction and the Y-axis direction is, for example, approximately 11 mm. The thickness of the support portion 17 is, for example, approximately 34 μm. The width of the space between the electrode portion 16 and the support portion 17 is, for example, approximately 0.5 to 1.5 mm.

[0031] The multiple elastic deformation portions 18 are located between the electrode portion 16 and the support portion 17 and surround the electrode portion 16 when viewed from the Z-axis direction. A space is formed between adjacent pairs of elastic deformation portions 18. Each elastic deformation portion 18 connects the electrode portion 16 and the support portion 17. That is, one end of each elastic deformation portion 18 is connected to the electrode portion 16, and the other end of each elastic deformation portion 18 is connected to the support portion 17. As an example, the multiple elastic deformation portions 18 are arranged at equal angular intervals in the circumferential direction. As an example, each elastic deformation portion 18 is formed in a rectangular plate shape extending in the radial direction. In the Fabry-Perot interference filter 1, the multiple elastic deformation portions 18 are a pair of elastic deformation portions 18 located on both sides of the electrode portion 16 in the X-axis direction and a pair of elastic deformation portions 18 located on both sides of the electrode portion 16 in the Y-axis direction. The width of each elastic deformation portion 18 in the radial direction is, for example, approximately 0.5 to 1.5 mm. The width of each elastic deformation portion 18 in a direction perpendicular to the radial direction is, for example, about 50 μm to 1 mm, and the thickness of each elastic deformation portion 18 is, for example, about 30 μm.

[0032] The thickness of each elastically deforming 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 elastically deforming portion 18, except for an 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 elastically deforming portion 18. The surface 16a on one side of the electrode portion 16, the surface 18a on one side of each elastically deforming 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 elastically deforming portion 18, and the surface 17c on 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 elastically deforming 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 that open outward on both sides (both sides in the circumferential direction) of one end of each elastically deforming portion 18.

[0033] 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. In other words, 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 the shape of a rectangular film extending 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, approximately 0.1 to 1 mm. The width of the metal pad 13 in the Y-axis direction is, for example, approximately 0.1 to 8 mm. The thickness of the metal pad 13 is, for example, approximately 1 μm.

[0034] In the first substrate 11 and 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.

[0035] The first reflective film 50 is disposed on the other surface 14b of the light-transmitting member 14. That is, the first layer 10 supports the first reflective film 50 at the movable portion 10a. The first reflective film 50 is movable in the Z-axis direction together with the movable portion 10a. As an example, the first reflective film 50 is formed in a circular film shape with the straight line L as its center line. In the Fabry-Perot interference filter 1, the first reflective film 50 includes a film made of Ag or an Ag alloy. That is, the first reflective film 50 includes a metal film. As an example, the first reflective film 50 is configured by forming a dielectric film made of aluminum oxide or the like on the surface opposite the surface 14b of a metal film made of Ag or an Ag alloy. The outer diameter of the first reflective film 50 is, for example, approximately 4 to 6 mm. The thickness of the first reflective film 50 is, for example, approximately 210 nm.

[0036] 4 and 6 , the second layer 20 is stacked 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.

[0037] 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 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. 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 having 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 210 described below. The second substrate 21 is made of 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, approximately 11 mm. The thickness of the second substrate 21 is, for example, approximately 0.5 mm. Note that 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.

[0038] A notch 210 is formed in the second substrate 21. The notch 210 opens on the opposite side of 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 surface 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. Rounded chamfered surfaces 210c are formed at the corners 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, approximately 1 mm. The width of the notch 210 in the Y-axis direction is, for example, approximately 1 to 10 mm.

[0039] The second electrodes 22 are disposed on the surface 21b of the second substrate 21. The surface 21b is the surface of the second layer 20 facing the first layer 10. When viewed from the Z-axis direction, the second electrodes 22 surround the light-transmitting region 1a and face the electrode portion 16 (i.e., the first electrodes 19) across a space in the Z-axis direction. As an example, the second electrodes 22 are arranged at equal angular intervals in the circumferential direction, 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 the shape of a film extending 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, approximately 1 mm. The width of each second electrode 22 in the circumferential direction is, for example, the value obtained by dividing the length of the circumference by the number of second electrodes 22 when multiple second electrodes 22 are lined up along the circumference. For example, when four second electrodes 22 are lined up along the circumference with a diameter of 5 mm, the width is approximately 4 mm. The thickness of each second electrode 22 is, for example, approximately 1 to 5 μm. The width of the gap between a pair of adjacent second electrodes 22 is, for example, approximately 0.1 mm. The initial distance between the electrode portion 16 (i.e., the first electrode 19) and each second electrode 22 (the distance between the first electrode 19 and each second electrode 22 when no potential difference is generated between the first electrode 19 and each second electrode 22) is, for example, approximately 3 μm.

[0040] In the Fabry-Perot interference filter 1, the multiple second electrodes 22 include a pair of second electrodes 22 located on both sides of the light-transmitting region 1a in the X-axis direction and a pair of second electrodes 22 located on both sides of the light-transmitting region 1a in the Y-axis direction. Each second electrode 22 includes a main body 22a and a pair of protrusions 22b. The main body 22a extends in the circumferential direction and faces the first electrode 19 across a space in the Z-axis direction. The pair of protrusions 22b protrude radially outward from the main body 22a and are located on both sides of the elastic deformation portion 18 in the circumferential direction when viewed from the Z-axis direction (see FIG. 5 ). The main body 22a has a notch 22c formed between the pair of protrusions 22b that opens outward. When viewed from the Z-axis direction, the notch 22c overlaps one end of the elastic deformation portion 18 and the pair of notches 16c on both sides of it (see FIG. 5 ).

[0041] 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. The light-shielding film 23 is a first metal film 27 that surrounds 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, approximately 3 to 5 mm. The outer diameter of the light-shielding film 23 is, for example, approximately 5 to 7 mm. The thickness of the light-shielding film 23 is, for example, about 1 to 5 μm. The light-shielding film 23 (that is, the first metal film 27) does not function as an electrode or wiring.

[0042] The plurality of third electrodes 24 are disposed on the surface 21a of the second substrate 21. The plurality of third electrodes 24 are a plurality of second metal films 28 surrounding the first metal film 27 when viewed from the Z-axis direction. In other words, the plurality of third electrodes 24 surround the light-transmitting region 1a when viewed from the Z-axis direction. As an example, the plurality of third electrodes 24 are arranged circumferentially at equal angular intervals, and a slit-like 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 the shape of a film extending in the circumferential direction, and a slit-like 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 radial width of each third electrode 24 is, for example, approximately 1 mm. The width of each third electrode 24 in the circumferential direction is, for example, the value obtained by dividing the length of the circumference by the number of third electrodes 24 when multiple third electrodes 24 are lined up along the circumference; for example, when four third electrodes 24 are lined up along the circumference with a diameter of 5 mm, the width is approximately 4 mm. The thickness of each third electrode 24 is, for example, approximately 1 to 5 μm. The width of the gap between a pair of adjacent third electrodes 24 is, for example, approximately 0.1 mm. The width of the gap between the light-shielding film 23 and each third electrode 24 is, for example, approximately 0.1 mm.

[0043] 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.

[0044] The electrode pads 25, together with the wirings 25a, are arranged on the surface 21a of the second substrate 21. Each third electrode 24 is electrically connected to each electrode pad 25 via each wiring 25a. In the Fabry-Perot interference filter 1, each electrode pad 25 is arranged at each of the four corners of the rectangular surface 21a and is formed in the shape of a circular film. Each wiring 25a connects one end of the third electrode 24 in the circumferential direction to the electrode pad 25 for the corresponding third electrode 24 and electrode pad 25. The material of each electrode pad 25 and each wiring 25a is, for example, a metal material such as Au. The outer diameter of each electrode pad 25 is, for example, approximately 0.5 to 1 mm. The width of each wiring 25a is, for example, approximately 0.1 to 0.5 mm. The thickness of each electrode pad 25 and each wiring 25a is, for example, approximately 1 to 5 μm.

[0045] In the Fabry-Perot interference filter 1, the light-shielding film 23 and the plurality of third electrodes 24 are formed of the same material. That is, the first metal film 27 and the plurality of second metal films 28 are formed of the same material. The plurality of electrode pads 25 and the plurality of wirings 25 a are formed integrally with the plurality of third electrodes 24 from the same material as the first metal film 27 and the second metal film 28.

[0046] A 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, thereby airtightly sealing the plurality of through holes. Each second electrode 22 is electrically connected to a corresponding third electrode 24 via at least two of the plurality of through electrodes 26. In the Fabry-Perot interference filter 1, each through electrode 26 connects the protrusion 22b of the second electrode 22 to the corresponding third electrode 24 in the corresponding second electrode 22 and the corresponding third electrode 24. That is, in the corresponding second electrode 22 and the corresponding third electrode 24, the second electrode 22 is electrically connected to the third electrode 24 via two through electrodes 26. Each through electrode 26 is made of a metal material such as Au. The length of each through electrode 26 in the Z-axis direction is, for example, approximately 0.5 mm. The width of each through electrode 26 in the direction perpendicular to the Z-axis direction is, for example, about 0.1 mm. The plurality of through electrodes 26 do not necessarily need to airtightly close the plurality of through holes formed in the second substrate 21.

[0047] 4 and 7 , the third layer 30 is stacked on the other side of the first layer 10. The third layer 30 includes a third substrate 31. 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.

[0048] 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 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. In other words, the third layer 30 is bonded to the first layer 10 in a bonding region R (the region between the surface 31a of the third substrate 31 and the surface 15b of the support member 15) that surrounds the light-transmitting region 1a when viewed from the Z-axis direction. 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 having 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, the outer edge of the third substrate 31 approximately coincides with the outer edge of the support member 15 when viewed from the Z-axis direction. The third substrate 31 is made of 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, approximately 11 mm. The thickness of the third substrate 31 is, for example, approximately 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.

[0049] The plurality of protrusions 80 are arranged on the surface 31a of the third substrate 31. The plurality of protrusions 80 are located outside the light-transmitting region 1a when viewed from the Z-axis direction. The plurality of protrusions 80 surround the light-transmitting region 1a when viewed from the Z-axis direction, and face the region of the first reflective film 50 located outside the light-transmitting region 1a in the Z-axis direction. As an example, each protrusion 80 is formed in a cylindrical shape. The material of each protrusion 80 is, for example, silicon oxide, silicon nitride, etc. The outer diameter of each protrusion 80 is, for example, about 0.1 mm. The height of each protrusion 80 in the Z-axis direction is, for example, about 50 nm.

[0050] The second reflective film 60 is disposed on the surface 31a of the third substrate 31. In other words, the third layer 30 supports the second reflective film 60. The region of the second reflective film 60 located outside the light-transmitting region 1a covers the multiple convex portions 80. As an example, the second reflective film 60 is formed in a circular shape with the straight line L as its center line. In the Fabry-Perot interference filter 1, when no potential difference is generated between the first electrode 19 and each second electrode 22, the portion of the second reflective film 60 located on each convex portion 80 contacts the region of the first reflective film 50 located outside the light-transmitting region 1a. This forms a space between the first reflective film 50 and the second reflective film 60 in the light-transmitting region 1a, preventing surface contact between the first reflective film 50 and the second reflective film 60. In the Fabry-Perot interference filter 1, the second reflective film 60 includes a film made of Ag or an Ag alloy. In other words, the second reflective film 60 includes a metal film. As an example, the second reflective film 60 is formed 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 an Ag alloy. 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. When no potential difference is generated between the first electrode 19 and each second electrode 22, the distance between the first reflective film 50 and the second reflective film 60 in the light-transmitting region 1a is, for example, about 50 nm.

[0051] 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 reflective film 50 and the second reflective film 60. One surface 70a of the absorbing film 70 has light absorption properties, and the other surface 70b of the absorbing film 70 has light reflection 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, approximately 3 to 5 mm.

[0052] 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 stacked in this order from the side opposite 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 one surface 70 a (at least light in the wavelength band that transmits through the first reflective film 50 and the second reflective film 60, the distance between which is variable). At the wavelength of light incident on the one surface 70 a, 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 one surface 70 a, 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 absorption 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, SiO ２ The resonant layer 72 is made of a dielectric material such as silicon dioxide. The thickness of the resonant layer 72 is, for example, within a range of ±20% centered on an integral multiple of one-fourth of the wavelength of light incident on one surface 70a (a reference wavelength such as the central wavelength). The material of the absorption layer 73 is, for example, a metal material such as Cr or Ti, or a silicide. The thickness of the absorption layer 73 is, for example, about 1 to 10 nm.

[0053] In the Fabry-Perot interference filter 1 configured as described above, when a voltage is applied to the first electrode 19 and the plurality of second electrodes 22 via the metal pad 13 and the plurality of electrode pads 25, a potential difference is generated between the first electrode 19 and the plurality of second electrodes 22, and an electrostatic force corresponding to the potential difference is generated between the first electrode 19 and the plurality of second electrodes 22. The generation of the electrostatic force between the first electrode 19 and the plurality of second electrodes 22 moves the movable part 10a to one side, changing the distance between the first reflective film 50 and the second reflective film 60. 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 reflective film 50 and the second reflective film 60. Therefore, by adjusting the voltage applied to the first electrode 19 and the plurality of second electrodes 22 (i.e., the potential difference generated between the first electrode 19 and the plurality of 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 airtightly bonded to one another, and the plurality of through holes formed in the second substrate 21 are airtightly blocked by the plurality of through electrodes 26, so that the movable portion 10a moves in the Z-axis direction in an airtight space. [Configuration of the first reflective film, the second reflective film, and the plurality of convex portions]

[0054] 4 and 9 , the first reflective film 50 is disposed on the surface 14b of the light transmitting member 14. The second reflective film 60 and the plurality of convex portions 80 are disposed on the surface 31a of the third substrate 31. The second reflective film 60 entirely covers each convex portion 80 on the surface 31a of the third substrate 31. That is, the second reflective film 60 covers each convex portion 80 on the surface 31a of the third substrate 31 so that the surface of each convex portion 80 is not exposed to the outside. A portion 62 of the second reflective film 60 located on each convex portion 80 faces the first reflective film 50 in the Z-axis direction. In the Fabry-Perot interference filter 1, the surface 14b of the light transmitting member 14 is the movable surface of the movable portion 10a on the third layer 30 side, and the surface 31a of the third substrate 31 is the fixed surface of the third layer 30 on the movable portion 10a side.

[0055] When viewed from the Z-axis direction, the outer edge 50a of the first reflection film 50 is located outside the multiple protrusions 80 that surround the light transmission region 1a, and inside the junction region R that extends in a frame shape (the side from the outer edge of the Fabry-Perot interference filter 1 toward the center of the Fabry-Perot interference filter 1 when viewed from the Z-axis direction, i.e., the inner side in the radial direction of the Fabry-Perot interference filter 1). In the Fabry-Perot interference filter 1, the outer edge 50a of the first reflection film 50 is located on the surface 14b of the light transmission member 14, within the airtight space defined by the first substrate 11, the semiconductor layer 12, the second substrate 21, and the third substrate 31. When viewed from the Z-axis direction, the outer edge 60a of the second reflection film 60 is located outside the multiple protrusions 80 that surround the light transmission region 1a, and inside the junction region R that extends in a frame shape. In the Fabry-Perot interference filter 1, the outer edge 60a of the second reflective film 60 is located on the surface 31a of the third substrate 31 within the airtight space defined by the first substrate 11, the semiconductor layer 12, the second substrate 21 and the third substrate 31.

[0056] The first reflective film 50 becomes thinner in an outer edge region 51 along the outer edge 50a as it approaches the outer edge 50a. The outer edge region 51 is a region located outside the plurality of convex portions 80 surrounding the light transmission region 1a when viewed from the Z-axis direction. The second reflective film 60 becomes thinner in an outer edge region 61 along the outer edge 60a as it approaches the outer edge 60a. The outer edge region 61 is a region located outside the plurality of convex portions 80 surrounding the light transmission region 1a when viewed from the Z-axis direction. In the Fabry-Perot interference filter 1, each of the first reflective film 50 and the second reflective film 60 is a film formed by physical vapor deposition (PVD) using a shadow mask.

[0057] Physical vapor deposition using a shadow mask includes vacuum deposition using a shadow mask, sputtering using a shadow mask, and ion plating using a shadow mask. As an example, the first reflective film 50 is formed as follows: First, a glass substrate that will become the first substrate 11 and a silicon substrate that will become the semiconductor layer 12 are bonded to each other. Next, the glass substrate and the silicon substrate are each etched to form the light-transmitting member 14, the support member 15, the electrode portion 16, the support portion 17, and the multiple elastically deforming portions 18. Next, the first reflective film 50 is formed on the surface 14b of the light-transmitting member 14 by physical vapor deposition using a shadow mask. Note that the outer edge 50a of the first reflective film 50 formed by physical vapor deposition using a shadow mask may reach the side surface of the light-transmitting member 14 or the surface 18b of each elastically deforming portion 18. As an example, the second reflective film 60 is formed as follows: First, multiple convex portions 80 are formed on the surface 31a of the third substrate 31 by film formation and patterning. Subsequently, the second reflective film 60 is formed on the surface 31 a of the third substrate 31 by physical vapor deposition using a shadow mask, and the second reflective film 60 covers the entirety of each of the convex portions 80 .

[0058] The area of ​​the top surface 62a of the portion 62 of the second reflective film 60 located on each convex portion 80 is smaller than the area of ​​the top surface 80a of each convex portion 80. When viewed from the Z-axis direction, the outer edge of the top surface 62a of the portion 62 of the corresponding convex portion 80 and portion 62 is located inside the outer edge of the top surface 80a of the convex portion 80. Each of the top surfaces 80a, 62a is a flat surface. As an example, for each convex portion 80 formed in a cylindrical shape, each portion 62 is formed in a truncated cone shape that includes the corresponding convex portion 80. When no potential difference is generated between the first electrode 19 and each second electrode 22, the portion 62 of the second reflective film 60 located on each convex portion 80 is in contact with the first reflective film 50. More specifically, when no potential difference occurs between the first electrode 19 and each second electrode 22, the portion 62 of the second reflective film 60 located on each convex portion 80 is in contact with a region of the first reflective film 50 located outside the light-transmitting region 1a and having a uniform film thickness.

[0059] In the Fabry-Perot interference filter 1, the first reflective film 50 and the second reflective film 60 each contain a film made of Ag or an Ag alloy, and therefore can selectively transmit light over a wide wavelength range in the visible region (e.g., approximately 400 to 700 nm). Examples of Ag alloys (alloys containing Ag as the main component) include AgSmCu (silver-samarium-copper alloy), AgC (silver-carbon alloy), AgBiNd (silver-bismuth-neodymium alloy), AgPdCu (silver-palladium-copper alloy), AgAu (silver-gold alloy), AgCu (silver-copper alloy), and AgCuAu (silver-copper-gold alloy). Films made of Ag have the advantage of lower light absorption and higher light reflectance compared to films made of Ag alloys. Films made of Ag alloys have the advantage of being less susceptible to deterioration (high corrosion resistance) compared to films made of Ag. [Operation and Effects]

[0060] In the Fabry-Perot interference filter 1, a plurality of convex portions 80 are arranged on the surface 31 a of the third layer 30. The second reflective film 60 covers the entirety of each of the convex portions 80 on the surface 31 a, and portions 62 of the second reflective film 60 located on each of the convex portions 80 face the first reflective film 50 in the Z-axis direction. As a result, when the first reflective film 50 approaches the second reflective film 60, the portions 62 of the second reflective film 60 located on each of the convex portions 80 come into contact with the first reflective film 50 before the first reflective film 50 comes into surface contact with the second reflective film 60 in the light transmission region 1 a, thereby suppressing sticking between the first reflective film 50 and the second reflective film 60. Furthermore, because the second reflective film 60 covers the entirety of each of the convex portions 80 on the surface 31 a, even if there is a difference in thermal expansion coefficient between the third substrate 31 of the third layer 30 and each of the convex portions 80, or even if an external force acts on the Fabry-Perot interference filter 1, the detachment of each of the convex portions 80 from the surface 31 a is suppressed. Moreover, because the outer edge 60 a of the second reflective film 60 is located inside the bonding region R between the first layer 10 and the third layer 30, deterioration, peeling, etc. of the second reflective film 60 is suppressed, and as a result, the effect of suppressing the detachment of each of the convex portions 80 from the surface 31 a is maintained. As described above, the Fabry-Perot interference filter 1 can stably suppress the occurrence of sticking between the first reflective film 50 and the second reflective film 60.

[0061] In the Fabry-Perot interference filter 1, the outer edges 50a of the first reflective film 50 and the outer edges 60a of the second reflective film 60 are located outside the multiple convex portions 80 when viewed from the Z-axis direction. This allows a wide area inward from the multiple convex portions 80 where the film thickness of both the first reflective film 50 and the second reflective film 60 is uniform. In other words, a wide light transmission region 1a can be ensured in the Fabry-Perot interference filter 1. More specifically, this is as follows. If the outer edges 50a of the first reflective film 50 are located inside the multiple convex portions 80 when viewed from the Z-axis direction, the outer edges 50a of the first reflective film 50, which are prone to film thickness variation, may be located near the light transmission region 1a. Similarly, if the outer edges 60a of the second reflective film 60 are located inside the multiple convex portions 80 when viewed from the Z-axis direction, the outer edges 60a of the second reflective film 60, which are prone to film thickness variation, may be located near the light transmission region 1a. Therefore, if at least one of the outer edge 50 a of the first reflection film 50 and the outer edge 60 a of the second reflection film 60 is located inside the multiple convex portions 80 when viewed from the Z-axis direction, there is a risk that the desired characteristics will not be obtained for the light passing through the light transmission region 1 a. In the Fabry-Perot interference filter 1, the outer edge 50 a of the first reflection film 50 and the outer edge 60 a of the second reflection film 60 are located outside the multiple convex portions 80 when viewed from the Z-axis direction, and therefore such a situation can be avoided.

[0062] In the Fabry-Perot interference filter 1, the area of ​​the top surface 62a of the portion 62 of the second reflection film 60 located on each convex portion 80 is smaller than the area of ​​the top surface 80a of each convex portion 80. As a result, when the first reflection film 50 comes into contact with the portion 62 of the second reflection film 60 located on each convex portion 80, the intermolecular force generated between the portion 62 of the second reflection film 60 located on each convex portion 80 and the first reflection film 50 is reduced, allowing the movable part 10a to move smoothly.

[0063] In the Fabry-Perot interference filter 1, the second reflective film 60 becomes thinner in the outer edge region 61 along the outer edge 60a as it approaches the outer edge 60a. This makes it even more difficult for the outer edge region 61 of the second reflective film 60 to peel off from the surface 31a, and therefore, it is possible to more stably suppress the detachment of each convex portion 80 from the surface 31a.

[0064] In the Fabry-Perot interference filter 1, each of the first reflective film 50 and the second reflective film 60 is a film formed by physical vapor deposition using a shadow mask. In a film formed by physical vapor deposition using a shadow mask, the outer edge region along the outer edge of the film becomes thinner as it approaches the outer edge of the film. Therefore, the outer edge region 51 of the first reflective film 50 becomes even less likely to peel off from the surface 14b, and the outer edge region 61 of the second reflective film 60 becomes even more unlikely to peel off from the surface 31a. Therefore, it is possible to more stably suppress the detachment of each convex portion 80 from the surface 31a.

[0065] In particular, in the Fabry-Perot interference filter 1, after the plurality of convex portions 80 are formed on the surface 31 a of the third substrate 31, the second reflective film 60 is formed on the surface 31 a of the third substrate 31 by physical vapor deposition using a shadow mask, and therefore the second reflective film 60 is not affected by etching for patterning the plurality of convex portions 80. Furthermore, in a manufacturing method in which the second reflective film 60 is obtained by forming a film that will become the second reflective film 60 and then performing additional processing on the film (such as removing unnecessary portions of the film), there is a risk that the second reflective film 60 will be deteriorated by the additional processing if, for example, the second reflective film 60 includes a film made of Ag or an Ag alloy. However, in a manufacturing method in which the second reflective film 60 is obtained by physical vapor deposition using a shadow mask, there is no need to perform additional processing on the second reflective film 60 after physical vapor deposition using a shadow mask, and therefore deterioration of the second reflective film 60 due to the additional processing can be avoided.

[0066] In the Fabry-Perot interference filter 1, the outer edge 50a of the first reflective film 50 and the outer edge 60a of the second reflective film 60 are located inside the junction region R when viewed from the Z-axis direction, and each of the first reflective film 50 and the second reflective film 60 includes a film made of Ag or an Ag alloy. Although films made of Ag or an Ag alloy are prone to deterioration, in the Fabry-Perot interference filter 1, the outer edge 50a of the first reflective film 50 and the outer edge 60a of the second reflective film 60 are located inside the junction region R between the first layer 10 and the third layer 30, and therefore deterioration, peeling, etc. of the first reflective film 50 and the second reflective film 60, which include films made of Ag or an Ag alloy, can be suppressed.

[0067] In particular, in the Fabry-Perot interference filter 1, the second reflective film 60 contains a "film made of Ag or an Ag alloy," which is a film that is prone to deterioration, and therefore the method of "forming the second reflective film 60 on the surface 31 a of the third substrate 31 by physical vapor deposition using a shadow mask after forming the multiple convex portions 80 on the surface 31 a of the third substrate 31," which does not affect the second reflective film 60 due to etching used to pattern the multiple convex portions 80, is extremely effective.

[0068] In the Fabry-Perot interference filter 1, when no potential difference is generated between the first electrode 19 and each second electrode 22, a portion 62 of the second reflective film 60 located on each convex portion 80 is in contact with the first reflective film 50. This results in a configuration in which a load is applied to each convex portion 80 when no potential difference is generated between the first electrode 19 and each second electrode 22, but even with such a configuration, the occurrence of sticking of the first reflective film 50 and the second reflective film 60 can be stably suppressed.

[0069] In the Fabry-Perot interference filter 1, the second layer 20 is stacked on the first layer 10 on the opposite side of the third layer 30 in the Z-axis direction, and multiple second electrodes 22 are arranged on the surface 21b of the second layer 20. This makes it possible to reliably support the multiple second electrodes 22 so as to face the first electrodes 19 across a space, and to appropriately generate electrostatic forces between the first electrodes 19 and each second electrode 22. [Modification]

[0070] The present disclosure is not limited to the above-described embodiment. In the above-described embodiment (hereinafter referred to as "the Fabry-Perot interference filter 1 in which the plurality of convex portions 80 are arranged on the surface 31 a of the third layer 30"), the portions 62 of the second reflective film 60 located on each convex portion 80 face the first reflective film 50 in the Z-axis direction. However, the portions 62 of the second reflective film 60 located on each convex portion 80 may face the surface 14 b of the movable portion 10 a in the Z-axis direction. That is, in the "Fabry-Perot interference filter 1 in which the plurality of convex portions 80 are arranged on the surface 31 a of the third layer 30," the outer edge 50 a of the first reflective film 50 may be located inside the plurality of convex portions 80 when viewed from the Z-axis direction. In this case, when no potential difference is generated between the first electrode 19 and each second electrode 22, the portions 62 of the second reflective film 60 located on each convex portion 80 come into contact with the surface 14 b of the movable portion 10 a.

[0071] In the "Fabry-Perot interference filter 1 in which multiple convex portions 80 are arranged on the surface 31a of the third layer 30," when no potential difference is generated between the first electrode 19 and each second electrode 22, the portion 62 of the second reflective film 60 located on each convex portion 80 may be separated from the surface 14b of the movable part 10a or the first reflective film 50.

[0072] 12 , the plurality of convex portions 80 located outside the light transmission region 1a when viewed from the Z-axis direction may be arranged on the surface 14b of the movable portion 10a (hereinafter referred to as "Fabry-Perot interference filter 1 in which the plurality of convex portions 80 are arranged on the surface 14b of the movable portion 10a"). In the "Fabry-Perot interference filter 1 in which the plurality of convex portions 80 are arranged on the surface 14b of the movable portion 10a," the first reflective film 50 covers the entirety of each convex portion 80 on the surface 14b, the outer edge 50a of the first reflective film 50 is located inside the bonding region R when viewed from the Z-axis direction, and the portion 52 of the first reflective film 50 located on the convex portion 80 faces the second reflective film 60 in the Z-axis direction.

[0073] In the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14b of the movable portion 10a," the plurality of convex portions 80 are arranged on the surface 14b of the movable portion 10a so as to be located outside the light transmission region 1a. The first reflective film 50 entirely covers each of the convex portions 80 on the surface 14b, and portions 52 of the first reflective film 50 located on the convex portions 80 face the second reflective film 60 in the Z-axis direction. As a result, when the first reflective film 50 approaches the second reflective film 60, the portions 52 of the first reflective film 50 located on each of the convex portions 80 come into contact with the second reflective film 60 before the first reflective film 50 comes into surface contact with the second reflective film 60 in the light transmission region 1a, thereby suppressing sticking between the first reflective film 50 and the second reflective film 60. Furthermore, because the first reflective film 50 covers the entirety of each of the convex portions 80 on the surface 14b, even if there is a difference in thermal expansion coefficient between the light transmitting member 14 of the movable portion 10a and each of the convex portions 80, or even if an external force acts on the Fabry-Perot interference filter 1, the detachment of each of the convex portions 80 from the surface 14b is suppressed. Moreover, because the outer edge 50a of the first reflective film 50 is located inside the bonding region R between the first layer 10 and the third layer 30, deterioration, peeling, etc. of the first reflective film 50 is suppressed, and as a result, the effect of suppressing the detachment of each of the convex portions 80 from the surface 14b is maintained. As described above, according to the "Fabry-Perot interference filter 1 having a plurality of convex portions 80 arranged on the surface 14b of the movable portion 10a," the occurrence of sticking of the first reflective film 50 and the second reflective film 60 can be stably suppressed.

[0074] In the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14b of the movable portion 10a," the outer edge 50a of the first reflective film 50 and the outer edge 60a of the second reflective film 60 may be located outside the plurality of convex portions 80 when viewed from the Z-axis direction. This makes it possible to ensure a wide area inward from the plurality of convex portions 80 where the film thickness of both the first reflective film 50 and the second reflective film 60 is uniform. In other words, it is possible to ensure a wide light transmission region 1a in the Fabry-Perot interference filter 1. More specifically, this is as follows. If the outer edge 50a of the first reflective film 50 is located inside the plurality of convex portions 80 when viewed from the Z-axis direction, the outer edge 50a of the first reflective film 50, which is prone to film thickness variation, may be located near the light transmission region 1a. Similarly, if the outer edge 60 a of the second reflective film 60 is located inside the plurality of convex portions 80 when viewed from the Z-axis direction, the outer edge 60 a of the second reflective film 60, which is prone to film thickness variation, may be located near the light-transmitting region 1 a. Therefore, if at least one of the outer edges 50 a of the first reflective film 50 and the outer edges 60 a of the second reflective film 60 is located inside the plurality of convex portions 80 when viewed from the Z-axis direction, desired characteristics may not be obtained for light transmitted through the light-transmitting region 1 a. In the "Fabry-Perot interference filter 1 in which the plurality of convex portions 80 are arranged on the surface 14 b of the movable part 10 a," such a situation can be avoided if the outer edge 50 a of the first reflective film 50 and the outer edge 60 a of the second reflective film 60 are located outside the plurality of convex portions 80 when viewed from the Z-axis direction.

[0075] In the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14b of the movable portion 10a," the area of ​​the top surface 52a of the portion 52 of the first reflective film 50 located on each convex portion 80 may be smaller than the area of ​​the top surface 80a of each convex portion 80. In this way, when the portion 52 of the first reflective film 50 located on each convex portion 80 comes into contact with the second reflective film 60, the intermolecular force generated between the portion 52 of the first reflective film 50 located on each convex portion 80 and the second reflective film 60 is reduced, thereby allowing the movable portion 10a to move smoothly.

[0076] In the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14b of the movable portion 10a," the first reflective film 50 may become thinner in the outer edge region 51 along the outer edge 50a as it approaches the outer edge 50a. This makes it even more difficult for the outer edge region 51 of the first reflective film 50 to peel off from the surface 14b, thereby more stably preventing the convex portions 80 from falling off from the surface 14b.

[0077] In the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14b of the movable portion 10a," each of the first reflective film 50 and the second reflective film 60 may be a film formed by physical vapor deposition using a shadow mask. A film formed by physical vapor deposition using a shadow mask becomes thinner in an outer edge region along the outer edge of the film as it approaches the outer edge. This makes it even more difficult for the outer edge region 51 of the first reflective film 50 to peel off from the surface 14b, and makes it even more difficult for the outer edge region 61 of the second reflective film 60 to peel off from the surface 31a. This makes it possible to more stably prevent the convex portions 80 from falling off the surface 14b.

[0078] In particular, in the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14 b of the movable portion 10 a," the plurality of convex portions 80 are formed on the surface 14 b of the movable portion 10 a, and then the first reflective film 50 is formed on the surface 14 b of the movable portion 10 a by physical vapor deposition using a shadow mask. Therefore, the first reflective film 50 is not affected by etching for patterning the plurality of convex portions 80. Furthermore, in a manufacturing method in which the first reflective film 50 is obtained by forming a film that becomes the first reflective film 50 and then performing additional processing on the film (such as removing unnecessary portions of the film), for example, if the first reflective film 50 includes a film made of Ag or an Ag alloy, the additional processing may deteriorate the first reflective film 50. However, in a manufacturing method in which the first reflective film 50 is obtained by physical vapor deposition using a shadow mask, it is not necessary to perform additional processing on the first reflective film 50 after physical vapor deposition using a shadow mask, and therefore deterioration of the first reflective film 50 due to the additional processing can be avoided.

[0079] In the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14b of the movable portion 10a," the outer edge 50a of the first reflective film 50 and the outer edge 60a of the second reflective film 60 are located inside the bonding region R when viewed from the Z-axis direction, and each of the first reflective film 50 and the second reflective film 60 may include a film made of Ag or an Ag alloy. Although a film made of Ag or an Ag alloy is prone to deterioration, because the outer edge 50a of the first reflective film 50 and the outer edge 60a of the second reflective film 60 are located inside the bonding region R between the first layer 10 and the third layer 30, deterioration, peeling, etc. of the first reflective film 50 and the second reflective film 60, which include a film made of Ag or an Ag alloy, can be suppressed.

[0080] In particular, in the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14b of the movable portion 10a," the first reflective film 50 contains a "film made of Ag or an Ag alloy," which is a film that is prone to deterioration. Therefore, the "method of forming a plurality of convex portions 80 on the surface 14b of the movable portion 10a, and then forming the first reflective film 50 on the surface 14b of the movable portion 10a by physical vapor deposition using a shadow mask," which does not affect the first reflective film 50 due to the etching used to pattern the plurality of convex portions 80, is extremely effective.

[0081] In the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14b of the movable portion 10a," when no potential difference is generated between the first electrode 19 and each of the second electrodes 22, the portion 52 of the first reflective film 50 located on each of the convex portions 80 may be in contact with the second reflective film 60. This results in a configuration in which a load is applied to each of the convex portions 80 when no potential difference is generated between the first electrode 19 and each of the second electrodes 22. However, even with such a configuration, the occurrence of sticking of the first reflective film 50 and the second reflective film 60 can be stably suppressed.

[0082] In the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14b of the movable portion 10a," the second layer 20 may be stacked on the first layer 10 on the side opposite to the third layer 30 in the Z-axis direction, and a plurality of second electrodes 22 may be arranged on the surface 21b of the second layer 20. This makes it possible to reliably support the plurality of second electrodes 22 so as to face the first electrodes 19 across a space, and to appropriately generate electrostatic forces between the first electrodes 19 and each of the second electrodes 22.

[0083] In the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14 b of the movable portion 10 a," the portion 52 of the first reflective film 50 located on each convex portion 80 may face the surface 31 a of the third layer 30 in the Z-axis direction. That is, in the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14 b of the movable portion 10 a," the outer edge 60 a of the second reflective film 60 may be located inside the plurality of convex portions 80 when viewed from the Z-axis direction. In that case, when no potential difference is generated between the first electrode 19 and each second electrode 22, the portion 52 of the first reflective film 50 located on each convex portion 80 will be in contact with the surface 31 a of the third layer 30.

[0084] In the "Fabry-Perot interference filter 1 in which multiple convex portions 80 are arranged on the surface 14b of the movable portion 10a," when no potential difference is generated between the first electrode 19 and each second electrode 22, the portion 52 of the first reflective film 50 located on the convex portion 80 may be separated from the surface 31a of the third layer 30 or the second reflective film 60.

[0085] Comparing the above-mentioned "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 31 a of the third layer 30" with the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14 b of the movable portion 10 a," the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 31 a of the third layer 30" is advantageous in that the manufacturing process can be simplified compared to the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14 b of the movable portion 10 a."

[0086] The Fabry-Perot interference filter 1 (including all Fabry-Perot interference filters 1 described in this specification; the same applies hereinafter) may have a single convex portion 80 located outside the light transmission region 1a when viewed from the Z-axis direction, instead of multiple convex portions 80 located outside the light transmission region 1a when viewed from the Z-axis direction. As an example, the single convex portion 80 is an annular wall portion extending along the outer edge of the light transmission region 1a when viewed from the Z-axis direction, and surrounds the light transmission region 1a when viewed from the Z-axis direction. However, when the Fabry-Perot interference filter 1 has multiple convex portions 80, the volume of each convex portion 80 can be reduced, and therefore, during manufacturing of the Fabry-Perot interference filter 1, it is possible to prevent each convex portion 80 from falling off from the surface 14b due to a difference in thermal expansion coefficient between the light transmission member 14 of the movable portion 10a and each convex portion 80, or to prevent each convex portion 80 from falling off from the surface 31a due to a difference in thermal expansion coefficient between the third substrate 31 of the third layer 30 and each convex portion 80. In the Fabry-Perot interference filter 1, for example, if at least one convex portion 80 has optical transparency or is of such a size that its influence can be ignored, the at least one convex portion 80 may be located within the optically transparent region 1a when viewed from the Z-axis direction.

[0087] In the Fabry-Perot interference filter 1, the outer edge 50a of the first reflection film 50 and the outer edge 60a of the second reflection film 60 may be located outside the plurality of convex portions 80 when viewed from the Z-axis direction, and the first reflection film 50 and the second reflection film 60 may be configured so that the metal film of the first reflection film 50 and the metal film of the second reflection film 60 are in contact with each other at least in portions corresponding to each convex portion 80. In this case, when these metal films come into contact with each other, the metal films can be made to have the same potential, and the generation of unnecessary electrostatic force between the first reflection film 50 and the second reflection film 60 can be suppressed.

[0088] In the Fabry-Perot interference filter 1, each of the first reflective film 50 and the second reflective film 60 may be composed only of a film made of Ag, an Ag alloy, or other metal material, or may be composed only of a dielectric film made of silicon oxide, titanium oxide, aluminum oxide, etc., or may be composed of a stack of multiple dielectric films.

[0089] In the Fabry-Perot interference filter 1, the second layer 20 may include one second electrode 22 facing the first electrode 19 across 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 via 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.

[0090] In the Fabry-Perot interference filter 1, the second layer 20 may include a plurality of first metal films 27 surrounding the light-transmitting region 1 a when viewed from the Z-axis direction. In this 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 across a space in the Z-axis direction, and one first metal film 27 surrounding the light-transmitting region 1 a when viewed from the Z-axis direction. In this 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.

[0091] In the Fabry-Perot interference filter 1, the first electrode 19 may be provided on the electrode unit 16. As an example, as shown in Fig. 10 , the first electrode 19 may be disposed on one surface of the electrode unit 16. In the example shown in Fig. 10 , the first electrode 19 is a single electrode that surrounds the light-transmitting region 1a when viewed from the Z-axis direction, and faces a plurality of second electrodes 22 across spaces in the Z-axis direction.

[0092] In the Fabry-Perot interference filter 1, the second layer 20 may further include a fourth electrode disposed on the surface 21 a of the second substrate 21. In this case, the fourth electrode may be electrically connected to the first electrode 19 via at least one through electrode 26.

[0093] In the Fabry-Perot interference filter 1, the first layer 10 includes a plurality of first electrodes 19 surrounding the light-transmitting region 1 a 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 1 a 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 reflective film 50 and the second reflective film 60 are parallel to each other.

[0094] In the Fabry-Perot interference filter 1, at least one third metal film surrounding the second metal film 28 may be disposed on the surface 21 a of the second substrate 21. In this case, similar to the light-shielding film 23, the at least one third metal film can function as a light-shielding film.

[0095] In the Fabry-Perot interference filter 1, the third layer 30 may not be stacked 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. As an example, as shown in FIG. 11 , the third layer 30 may not be stacked on the first layer 10 on the other side of the first layer 10, and the second reflective film 60 may be disposed on the surface 21b of the second substrate 21 of the second layer 20. In the example shown in FIG. 11 , a recess that opens to the first layer 10 side is formed in the second substrate 21, and the bottom surface of the recess serves as the surface 21b. The first reflective film 50 is disposed on the surface 11a of the first substrate 11 of the first layer 10 on the second layer 20 side. The first substrate 11 has a groove 11c formed on its surface 11b opposite to the second layer 20, the groove 11c surrounding the first reflective film 50 and the first electrode 19 when viewed from the Z-axis direction, and the inner portion of the groove 11c is configured as the movable portion 10a. In this case, the bottom of the groove 11c functions as an elastic deformation portion. Note that even when the third layer 30 is stacked on the first layer 10, the second layer 20, rather than the third layer 30, may support the second reflective film 60.

[0096] In the example shown in FIG. 11 , the first layer 10 is a "movable layer that includes a first electrode 19 and supports the first reflective film 50 in the movable portion 10 a," and the second layer 20 is a "fixed layer that supports the second reflective film 60." In the example shown in FIG. 11 , a second electrode 22 that faces the first electrode 19 across a space in the Z-axis direction is disposed on the surface 21 b of the second substrate 21. That is, in the example shown in FIG. 11 , the second electrode 22 is supported by the second layer 20, which is a fixed layer. Note that although the illustration of the convex portions 80 is omitted in the example shown in FIG. 11 , at least one convex portion 80 located outside the light-transmitting region 1 a when viewed from the Z-axis direction is disposed on the surface 11 a of the first substrate 11 or the surface 21 b of the second substrate 21, and the first reflective film 50 or the second reflective film 60 entirely covers at least one convex portion 80.

[0097] In the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 31 a of the third layer 30," the plurality of convex portions 80 may be formed integrally with the third substrate 31. In the "Fabry-Perot interference filter 1 in which a plurality of convex portions 80 are arranged on the surface 14 b of the movable portion 10 a," the plurality of convex portions 80 may be formed integrally with the light transmitting member 14.

[0098] 1...Fabry-Perot interference filter, 1a...light transmission region, 10...first layer (movable layer), 10a...movable portion, 14b...surface (movable surface), 19...first electrode, 20...second layer (wiring layer), 21b...surface, 22...second electrode, 30...third layer (fixed layer), 31a...surface (fixed surface), 50...first reflective film, 50a...outer edge, 51...outer edge region, 52...portion, 52a...top surface, 60...second reflective film, 60a...outer edge, 61...outer edge region, 62...portion, 62a...top surface, 80...convex portion, 80a...top surface, R...junction region.

Claims

a movable layer including a first electrode and supporting the first reflection film in a movable section movable in a first direction in which the first reflection film and the second reflection film face each other; a fixed layer bonded to the movable layer in a bonding region surrounding the light transmission region when viewed from the first direction and supporting the second reflection film; a second electrode facing the first electrode via a space in the first direction; and a convex portion disposed on a movable surface of the movable section facing the fixed layer or on a fixed surface of the fixed layer facing the movable section, wherein when the convex portion is disposed on the movable surface, the first reflection film covers the entire convex portion on the movable surface, an outer edge of the first reflection film is located inside the bonding region when viewed from the first direction, and a portion of the first reflection film located on the convex portion faces the fixed surface or the second reflection film in the first direction, A Fabry-Perot interference filter, wherein when the convex portion is arranged on the fixed surface, the second reflective film covers the entire convex portion on the fixed surface, the outer edge of the second reflective film is located inside the bonding area when viewed from the first direction, and the portion of the second reflective film located on the convex portion faces the movable surface or the first reflective film in the first direction.

2. The Fabry-Perot interference filter according to claim 1, wherein the convex portion is disposed on the fixing surface.

3. A Fabry-Perot interference filter as described in claim 1 or 2, wherein the outer edge of the first reflecting film and the outer edge of the second reflecting film are located outside the convex portion when viewed from the first direction.

4. The Fabry-Perot interference filter according to claim 3, wherein each of the first and second reflective films includes a metal film.

5. A Fabry-Perot interference filter according to any one of claims 1 to 4, wherein, when the convex portion is arranged on the movable surface, the top surface area of ​​the portion of the first reflective film located on the convex portion is smaller than the top surface area of ​​the convex portion, and when the convex portion is arranged on the fixed surface, the top surface area of ​​the portion of the second reflective film located on the convex portion is smaller than the top surface area of ​​the convex portion.

6. A Fabry-Perot interference filter according to any one of claims 1 to 5, wherein, when the convex portion is arranged on the movable surface, the first reflective film becomes thinner in an outer edge region along the outer edge of the first reflective film as it approaches the outer edge of the first reflective film, and when the convex portion is arranged on the fixed surface, the second reflective film becomes thinner in an outer edge region along the outer edge of the second reflective film as it approaches the outer edge of the second reflective film.

7. A Fabry-Perot interference filter according to any one of claims 1 to 6, wherein each of the first reflective film and the second reflective film is a film formed by physical vapor deposition using a shadow mask.

8. A Fabry-Perot interference filter according to any one of claims 1 to 7, wherein the outer edge of the first reflective film and the outer edge of the second reflective film are located inside the junction region when viewed from the first direction, and each of the first reflective film and the second reflective film includes a film made of Ag or an Ag alloy.

9. A Fabry-Perot interference filter according to any one of claims 1 to 8, wherein the convex portion is a plurality of convex portions surrounding the light transmitting region when viewed from the first direction.

10. A Fabry-Perot interference filter according to any one of claims 1 to 9, wherein, when the convex portion is disposed on the movable surface, a portion of the first reflective film located on the convex portion is in contact with the fixed surface or the second reflective film when no potential difference is generated between the first electrode and the second electrode, and, when the convex portion is disposed on the fixed surface, a portion of the second reflective film located on the convex portion is in contact with the movable surface or the first reflective film when no potential difference is generated between the first electrode and the second electrode.

11. A Fabry-Perot interference filter as described in any one of claims 1 to 10, further comprising a wiring layer stacked on the movable layer on the side opposite the fixed layer in the first direction, and the second electrode is arranged on the surface of the wiring layer facing the movable layer.

Images