Fabry-perot interference filter

Abstract

The Fabry-Perot interference filter includes: a first laminate having a first mirror portion; and a second laminate having a second mirror section facing the first mirror section with a gap therebetween. A reference laminate, which is either the first laminate or the second laminate, has a first low-resistance layer, a second low-resistance layer, and a first insulating layer disposed between the first low-resistance layer and the second low-resistance layer. The resistivity of the material constituting the first low-resistance layer and the second low-resistance layer is smaller than the resistivity of the material constituting the first insulating layer. The first insulating layer has: a first main body part located on the first low-resistance layer; a first covering portion covering an outer edge of the first low resistance layer; and a first peripheral portion located outside the first low resistance layer. The first main body portion, the first cover portion, and the first peripheral edge portion are integrally formed.

Description

Technical Field

[0001] One aspect of the present invention relates to a Fabry-Perot interferometer filter. Background Technology

[0002] Patent Document 1 describes a Fabry-Perot interferometer filter in which a first stack, an intermediate layer, and a second stack are sequentially stacked on a substrate. The first and second stacks are each constructed by alternately stacking multiple polysilicon layers and multiple silicon nitride layers. A portion of each of the first and second stacks functions as a first and a second reflector, respectively. In the Fabry-Perot interferometer filter, the distance between the first and second reflectors is adjusted by regulating the voltage applied between them, allowing for appropriate selection of the wavelength of light transmitted through the filter.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2019 / 098142 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] In manufacturing the Fabry-Perot interferometer filter as described above, the first and second stacks are formed, for example, by etching. During this formation, there is a possibility of misalignment of the resist used as the etching mask, resulting in leakage paths at the edges of the first or second stack. For example, if the outer edge of the silicon nitride layer between the two polysilicon layers is removed larger than intended, the polysilicon layers at their outer edges may come into contact with each other, potentially creating leakage paths between the polysilicon layers. Alternatively, if the outer edge of a polysilicon layer is formed larger than intended and comes into contact with the outer edge of the underlying polysilicon layer, leakage paths may also occur between the polysilicon layers. To accurately adjust the voltage applied between the first and second mirrors and thus the distance between them, it is necessary to suppress the generation of such leakage paths.

[0008] One aspect of the present invention is to provide a Fabry-Perot interferometer filter capable of controlling the distance between a first mirror portion and a second mirror portion with good precision.

[0009] Technical means for solving technical problems

[0010] [1] A Fabry-Perot interference filter of one aspect of the present invention includes: a substrate; a first laminate having a first mirror portion disposed on the substrate; a second laminate having a second mirror portion facing the first mirror portion across a gap on the side of the first mirror portion opposite to the substrate; and an intermediate layer defining the gap between the first laminate and the second laminate, wherein a reference laminate serving as one of the first laminate and the second laminate has: a first low-resistivity layer; a second low-resistivity layer disposed on the side of the first low-resistivity layer opposite to the substrate; and a first insulating layer disposed between the first low-resistivity layer and the second low-resistivity layer, wherein the resistivity of the materials constituting the first low-resistivity layer and the second low-resistivity layer is lower than the resistivity of the material constituting the first insulating layer, the first insulating layer having: a first body portion located on the first low-resistivity layer; a first cover portion covering the outer edge of the first low-resistivity layer; and a first peripheral portion located at a position outside the first low-resistivity layer when viewed from a direction perpendicular to the substrate, wherein the first body portion, the first cover portion, and the first peripheral portion are integrally formed.

[0011] In this Fabry-Perot interferometer filter, in a reference stack that serves as both a first and a second stack, the first insulating layer has: a first main body portion located on a first low-resistivity layer, a first cover portion covering the outer edge of the first low-resistivity layer, and a first peripheral portion located outside the first low-resistivity layer when viewed from a direction perpendicular to the substrate. The first main body portion, the first cover portion, and the first peripheral portion are integrally formed. Therefore, by utilizing the first cover portion and the first peripheral portion of the first insulating layer, contact between the second low-resistivity layer and the first low-resistivity layer can be prevented, and leakage paths caused by contact between the second and first low-resistivity layers can be suppressed. Thus, according to this Fabry-Perot interferometer filter, the distance between the first and second reflector portions can be adjusted with good precision.

[0012] [2] One aspect of the Fabry-Perot interference filter of the present invention may be the Fabry-Perot interference filter described in [1], wherein the reference laminate has: a third low-resistance layer disposed on the substrate side of the first low-resistance layer; and a second insulating layer disposed between the first low-resistance layer and the third low-resistance layer, wherein the resistivity of the material constituting the third low-resistance layer is less than the resistivity of the material constituting the second insulating layer. Even with such a structure, the distance between the first reflector portion and the second reflector portion can be adjusted with good precision.

[0013] [3] In one aspect, the Fabry-Perot interferometer filter of the present invention may be the Fabry-Perot interferometer filter described in [2], wherein the first covering portion covers the outer edge of the first low-resistivity layer, the outer edge of the third low-resistivity layer and the outer edge of the second insulating layer. In this case, in addition to preventing the second low-resistivity layer from contacting the first low-resistivity layer, it is also possible to prevent the first low-resistivity layer from contacting the third low-resistivity layer, thereby further suppressing the generation of leakage paths.

[0014] [4] In one aspect, the Fabry-Perot interferometer filter of the present invention may be the Fabry-Perot interferometer filter described in [2] or [3], wherein the second low-resistance layer extends in such a way as to cover the first cover portion of the first insulating layer. In this case, for example, compared to the case where the second low-resistance layer is formed to cover only the first body portion of the first insulating layer, the step formed on the reference laminate can be made gentler. By making the step formed on the reference laminate gentler, for example, uneven coating during the application of resist for etching can be suppressed, thereby improving manufacturing stability.

[0015] [5] One aspect of the Fabry-Perot interferometer filter of the present invention may be the Fabry-Perot interferometer filter described in [1], wherein the reference laminate further comprises: a third insulating layer disposed on the side of the second low-resistivity layer opposite to the substrate, the third insulating layer comprising: a second body portion located on the second low-resistivity layer; a second cover portion covering the outer edge of the second low-resistivity layer; and a second peripheral portion located at a position further outward than the second low-resistivity layer when viewed from a direction perpendicular to the substrate, the second body portion, the second cover portion, and the second peripheral portion being integrally formed. In this case, for example, it is possible to prevent the low-resistivity layer laminated on the second insulating layer from contacting the second low-resistivity layer, and the generation of leakage paths can be further suppressed.

[0016] [6] In one aspect, the Fabry-Perot interference filter of the present invention may be the Fabry-Perot interference filter described in [5], wherein the second peripheral portion contacts the first peripheral portion. In this case, contact between low-resistance layers can be prevented more reliably, and the generation of leakage paths can be further suppressed.

[0017] [7] In one aspect, the Fabry-Perot interference filter of the present invention may be the Fabry-Perot interference filter described in [5] or [6], wherein the reference laminate further comprises a fourth low-resistance layer disposed on the side of the third insulating layer opposite to the substrate. In this case, the second cover portion and the second peripheral portion of the third insulating layer can prevent the fourth low-resistance layer from contacting the second low-resistance layer.

[0018] [8] One aspect of the Fabry-Perot interferometer filter of the present invention may be any one of [1] to [7], wherein at least one of the first low-resistivity layer and the second low-resistivity layer is electrically connected to an electrode. In such a structure, it is particularly important to suppress the generation of leakage paths between the first low-resistivity layer and the second low-resistivity layer. According to this Fabry-Perot interferometer filter, as described above, the generation of leakage paths caused by the contact between the first low-resistivity layer and the second low-resistivity layer can be suppressed.

[0019] [9] One aspect of the Fabry-Perot interference filter of the present invention may be any one of [1] to [8], wherein the intermediate layer has: a third main body portion located on the first laminate; a third cover portion covering the outer edge of the first laminate; and a third peripheral portion located at a position further outward than the first laminate when viewed from a direction perpendicular to the substrate, wherein the third main body portion, the third cover portion, and the third peripheral portion are integrally formed. In this case, since the outer edge of the first laminate is covered by the intermediate layer, peeling of the first laminate can be suppressed.

[0020]

[10] One aspect of the Fabry-Perot interferometer filter of the present invention may be any one of [1] to [9], wherein the reference laminate is the first laminate, and the second laminate has: a fourth main body portion located on the intermediate layer; a fourth cover portion covering the outer edge of the intermediate layer; and a fourth peripheral portion located outside the intermediate layer when viewed from a direction perpendicular to the substrate, wherein the fourth main body portion, the fourth cover portion, and the fourth peripheral portion are integrally formed. In this case, since the outer end face of the intermediate layer is covered by the second laminate, peeling between the first laminate and the intermediate layer can be suppressed.

[0021]

[11] In one aspect, the Fabry-Perot interferometer filter of the present invention may be any one of [1] to

[10] , wherein the first low-resistance layer and the second low-resistance layer are formed of polysilicon, and the first insulating layer is formed of silicon nitride. In this case, the desired mirror characteristics can be achieved.

[0022]

[12] One aspect of the Fabry-Perot interferometer filter of the present invention may be any one of [1] to

[11] , wherein the other of the first laminate and the second laminate has: a fifth low-resistivity layer; a sixth low-resistivity layer disposed on the side of the fifth low-resistivity layer opposite to the substrate; and a fourth insulating layer disposed between the fifth low-resistivity layer and the sixth low-resistivity layer, wherein the resistivity of the materials constituting the fifth low-resistivity layer and the sixth low-resistivity layer is less than the resistivity of the material constituting the fourth insulating layer, and the fourth insulating layer has: a fifth main body portion located on the fifth low-resistivity layer; a fifth cover portion covering the outer edge of the fifth low-resistivity layer; and a fifth peripheral portion located at a position further outward than the fifth low-resistivity layer when viewed from a direction perpendicular to the substrate, wherein the fifth main body portion, the fifth cover portion, and the fifth peripheral portion are integrally formed. In this case, by utilizing the fifth cover portion and the fifth peripheral portion of the fourth insulating layer, it is possible to prevent the sixth low-resistivity layer from contacting the fifth low-resistivity layer, and to suppress leakage paths caused by contact between the sixth low-resistivity layer and the fifth low-resistivity layer.

[0023]

[13] In one aspect, the Fabry-Perot interferometer filter of the present invention may be any one of [1] to

[12] , wherein the reference stack is the first stack. In this case, the generation of leakage paths in the first stack can be suppressed.

[0024]

[14] In one aspect, the Fabry-Perot interferometer filter of the present invention may be any one of [1] to [2], wherein the reference stack is the second stack. In this case, the generation of leakage paths in the second stack can be suppressed.

[0025] The effects of the invention

[0026] According to one aspect of the present invention, a Fabry-Perot interferometer filter is provided that can control the distance between the first reflector portion and the second reflector portion with good precision. Attached Figure Description

[0027] Figure 1 This is a top view of the Fabry-Perot interference filter according to the implementation method.

[0028] Figure 2 This is a bottom view of the Fabry-Perot interferometer filter.

[0029] Figure 3 It is along Figure 1 A cross-sectional view of line III-III.

[0030] Figure 4This is a magnified cross-sectional view showing a portion of a Fabry-Perot interferometer filter.

[0031] Figure 5 This is a cross-sectional view of the first modified Fabry-Perot interferometer filter.

[0032] Figure 6 This is a cross-sectional view of the second variation of the Fabry-Perot interferometer filter.

[0033] Figure 7 This is a cross-sectional view of the third variation of the Fabry-Perot interferometer filter. Detailed Implementation

[0034] Hereinafter, an embodiment of one aspect of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent elements are referred to by the same reference numerals, and repeated descriptions are omitted.

[0035] [Structure of a Fabry-Perot interferometer filter]

[0036] like Figures 1-3 As shown, the Fabry-Perot interference filter 1 includes a substrate 11. The substrate 11 has a first surface 11a and a second surface 11b located on the side opposite to the first surface 11a. An antireflective layer 21, a first laminate 22 (refer to the laminate), an intermediate layer 23, and a second laminate 24 are sequentially stacked on the first surface 11a. A gap (in other words, an air gap) S is defined between the first laminate 22 and the second laminate 24 by a frame-shaped intermediate layer 23.

[0037] The shapes and positional relationships of the various parts when viewed from a direction perpendicular to the first surface 11a (in other words, when viewed from above) are as follows: The outer edge of the substrate 11 is, for example, a rectangle with a side length of several hundred μm to several tens of mm. The outer edge of the substrate 11 coincides with the outer edge of the second laminate 24. The outer edge of the antireflective layer 21 coincides with the outer edge of the first laminate 22. The outer edge of the intermediate layer 23 is located further outward than the outer edges of the antireflective layer 21 and the first laminate 22 (in other words, on the side opposite to the center of the gap S), and further inward than the outer edges of the substrate 11 and the second laminate 24 (in other words, on the side opposite to the center of the gap S). That is, the substrate 11 has an outer edge portion 11c located further outward than the outer edge of the intermediate layer 23. The outer edge portion 11c is, for example, frame-shaped, surrounding the intermediate layer 23 when viewed from above. The gap S is, for example, circular. Furthermore, the outer edge of the anti-reflective layer 21 can be located further outward than the outer edge of the intermediate layer 23; the outer edge of the anti-reflective layer 21 can also coincide with the outer edge of the intermediate layer 23. The anti-reflective layer 21 and the intermediate layer 23 can also be integrated together.

[0038] The Fabry-Perot interferometer filter 1 allows light of a specific wavelength to pass through a light-transmitting region 1a defined in its central portion. The light-transmitting region 1a is, for example, a cylindrical region. The substrate 11 is made of, for example, silicon, quartz, or glass. When the substrate 11 is made of silicon, the anti-reflective layer 21 and the intermediate layer 23 are, for example, made of silicon oxide. The intermediate layer 23 is insulating. The thickness of the intermediate layer 23 is, for example, tens of nm to tens of μm.

[0039] The portion of the first laminate 22 corresponding to the light-transmitting region 1a (e.g., the portion overlapping the gap S when viewed from above) functions as the first reflector section 31. The first reflector section 31 is a fixed reflector. The first reflector section 31 is disposed on the first surface 11a through the anti-reflection layer 21. The first laminate 22 is constructed, for example, by alternately stacking multiple polysilicon layers 50 and multiple silicon nitride layers 60 layer by layer. In the Fabry-Perot interferometer filter 1, polysilicon layer 51, silicon nitride layer 61, polysilicon layer 52, silicon nitride layer 62, and polysilicon layer 53 are sequentially stacked on the anti-reflection layer 21. The optical thickness of each of the polysilicon layer 50 and silicon nitride layer 60 constituting the first reflector section 31 is preferably an integer multiple of 1 / 4 of the center transmission wavelength. Alternatively, the first reflector section 31 may be disposed directly on the first surface 11a without being separated by the anti-reflection layer 21.

[0040] The portion of the second laminate 24 corresponding to the light-transmitting region 1a (e.g., the portion overlapping the gap S when viewed from above) functions as the second reflector portion 32. The second reflector portion 32 is a movable reflector. The second reflector portion 32 is located opposite the first reflector portion 31 to the substrate 11 on the side opposite to the first reflector portion 31, separated by the gap S. The direction in which the first reflector portion 31 and the second reflector portion 32 face each other is perpendicular to the first surface 11a. The second laminate 24 is disposed on the first surface 11a, separated by the anti-reflective layer 21, the first laminate 22, and the intermediate layer 23. The second laminate 24 is constructed, for example, by alternately stacking multiple polysilicon layers 50 and multiple silicon nitride layers 60. In the Fabry-Perot interference filter 1, polysilicon layer 54, silicon nitride layer 64, polysilicon layer 55, silicon nitride layer 65, and polysilicon layer 56 are sequentially stacked on the intermediate layer 23. The optical thickness of each of the polysilicon layer 50 and silicon nitride layer 60 constituting the second reflector portion 32 is preferably an integer multiple of 1 / 4 of the center transmission wavelength. The thickness of the first stack 22 and the second stack 24 is, for example, about 1 μm, and the thickness of each of the polysilicon layer 50 and silicon nitride layer 60 constituting the first stack 22 and the second stack 24 is, for example, about 0.01 μm to 0.5 μm.

[0041] Polysilicon layer 50 is a low-resistivity layer, and silicon nitride layer 60 is an insulating layer. The resistivity of the material constituting the low-resistivity layer (polysilicon layer 50) is less than the resistivity of the material constituting the insulating layer (silicon nitride layer 60). In this example, the resistivity of the polysilicon constituting polysilicon layer 50 is 1.0 × 10⁻⁶. 5 Ωcm~1.0×10 6 The resistivity of the silicon nitride layer 60, which consists of silicon nitride with a resistivity of approximately Ωcm, is 1.0 × 10⁻⁶. 8 Ωcm or higher. In addition, as will be described later, in this example, the polysilicon layer 50 is locally made low-resistivity by doping with impurities to form electrode portions (driving electrode 12, compensation electrode 13 and driving electrode 14), but as described above, even in the state before this low-resistivity is achieved, the resistivity of the polysilicon layer 50 is less than the resistivity of the silicon nitride layer 60.

[0042] In the second stack 24, a plurality of through holes (not shown) are formed in the portion corresponding to the gap S (e.g., the portion overlapping the gap S when viewed from above). These through holes extend from the surface 24a of the second stack 24 opposite to the intermediate layer 23 to the gap S. These through holes are formed to a degree that substantially does not affect the function of the second reflector portion 32. These through holes are used, for example, to form the gap S by etching away a portion of the intermediate layer 23.

[0043] like Figure 3 As shown, a driving electrode 12 and a compensation electrode 13 are provided in the first reflector portion 31. The driving electrode 12, when viewed from above, is, for example, annular in shape, surrounding the light-transmitting region 1a. The driving electrode 12 is, for example, formed on the polysilicon layer 53 constituting the first laminate 22. The polysilicon layer 53 is the layer in the first laminate 22 that is in contact with the intermediate layer 23; in other words, it is the layer located on the side furthest from the substrate 11. The driving electrode 12 is formed, for example, by doping impurities to reduce the resistance of the polysilicon layer 53.

[0044] The compensation electrode 13, when viewed from above, is, for example, circular in shape and overlaps with the light-transmitting region 1a. The size of the compensation electrode 13 can be the entire size including the light-transmitting region 1a, or it can be approximately the same size as the light-transmitting region 1a. The compensation electrode 13 is formed on the polysilicon layer 53 on which the driving electrode 12 is formed. The compensation electrode 13 is formed, for example, by doping impurities to reduce the resistance of the polysilicon layer 53.

[0045] A driving electrode 14 is provided in the second reflector portion 32. The driving electrode 14 is, for example, circular in shape when viewed from above, and is positioned opposite the driving electrode 12 and the compensation electrode 13 through a gap S. The driving electrode 14 is, for example, formed on the polysilicon layer 54 constituting the second stack 24. The polysilicon layer 54 is the layer in the second stack 24 that is in contact with the intermediate layer 23; in other words, it is the layer located closest to the substrate 11. The driving electrode 14 is formed, for example, by doping the polysilicon layer 54 with impurities to reduce its resistance.

[0046] The Fabry-Perot interference filter 1 also includes a pair of terminals 15 and a pair of terminals 16. When viewed from above, terminals 15 and 16 are positioned outside the light-transmitting region 1a. Terminals 15 and 16 are formed, for example, of a metal film such as aluminum or its alloy. Terminals 15 face each other across the light-transmitting region 1a, and terminals 16 face each other across the light-transmitting region 1a. The directions in which terminals 15 face each other are orthogonal to the directions in which terminals 16 face each other (see reference). Figure 1 ).

[0047] Terminal 15 is disposed within a through-hole H1 extending from the surface 24a of the second laminate 24 to the first laminate 22. Terminal 15 is electrically connected to the drive electrode 12 via a wiring portion 17. The wiring portion 17 is formed on a polysilicon layer 53. The polysilicon layer 53 is electrically connected to the drive electrode 12 via the wiring portion 17. The wiring portion 17 is formed, for example, by doping the polysilicon layer 53 to reduce its resistance. Terminal 15 has an opening 15a that opens on the side opposite to the substrate 11. Intermediate layer 23 has an inner surface 23a that defines the through-hole H1. The opening edge 15b of the opening 15a, when viewed from above, extends throughout the entire circumference (in other words, at any position on the opening edge 15b) and is located further inward than the inner surface 23a.

[0048] Terminal 16 is disposed within a through-hole H2 extending from the surface 24a of the second laminate 24 to the interior of the intermediate layer 23. Terminal 16 is electrically connected to the compensation electrode 13 and the driving electrode 14 via wiring portion 18. Thus, when the Fabry-Perot interference filter 1 is driven, the compensation electrode 13 becomes at the same potential as the driving electrode 14. Wiring portion 18 includes, for example, wiring portion 18a formed on polysilicon layer 52, wiring portion 18b formed on polysilicon layer 53, and wiring portion 18c formed on polysilicon layer 54. Wiring portion 18a is electrically connected to the compensation electrode 13. Polysilicon layer 52 is electrically connected to the compensation electrode 13 and the driving electrode 14 via wiring portion 18a. Wiring portion 18c is electrically connected to the driving electrode 14. Wiring portion 18b contacts wiring portions 18a and 18c, and wiring portions 18a to 18c are electrically connected to each other. Each of the wiring portions 18a to 18c is formed, for example, when the polysilicon layers 52, 53, and 54 are polysilicon layers, by doping impurities to reduce the resistance of the polysilicon layers 52, 53, or 54. Terminal 16 has an opening 16a on the side opposite to the substrate 11. The intermediate layer 23 has an inner surface 23b defining the through-hole H2. When viewed from above, the opening edge 16b of the opening 16a is located further inward than the inner surface 23b throughout the entire circumference (in other words, at any position on the opening edge 16b). When viewed from above, the outer edge 16c of the terminal 16 is located further outward than the inner surface 23b throughout the entire circumference.

[0049] Trench T1 and trench T2 are provided in the first layer 22. Trench T1 is formed in the polysilicon layer 53 and extends in a ring shape to surround the connection portion of the wiring portion 18 connected to the terminal 16. Trench T1 electrically insulates the driving electrode 12 from the wiring portion 18. Trench T2 is formed in the polysilicon layer 53 and extends in a ring shape along the boundary between the driving electrode 12 and the compensation electrode 13. Trench T2 electrically insulates the driving electrode 12 from the region inside the driving electrode 12 (i.e., the compensation electrode 13). Through trenches T1 and T2, the driving electrode 12 and the compensation electrode 13 are electrically insulated. The regions within each trench T1 and T2 can be insulating material or voids.

[0050] A trench T3 is provided in the second laminate 24. The trench T3 has a first portion T3a and a second portion T3b. The first portion T3a is continuously formed over the polysilicon layers 55, 56 and the silicon nitride layers 64, 65, extending in a ring shape to surround the terminal 15. The second portion T3b is formed on the polysilicon layer 54 and extends in a ring shape to surround the terminal 15. The second portion T3b is spaced apart from the first portion T3a. When viewed from above, the second portion T3b is located on the outer side of the entire circumference compared to the first portion T3a. The trench T3 electrically insulates the terminal 15 from the drive electrode 14. The area within the trench T3 can be an insulating material or a void.

[0051] An antireflective layer 41, a third laminate 42, an intermediate layer 43, and a fourth laminate 44 are sequentially stacked on the second surface 11b of the substrate 11. The antireflective layer 41 and the intermediate layer 43 have the same structure as the antireflective layer 21 and the intermediate layer 23, respectively. The third laminate 42 and the fourth laminate 44 have a stacked structure symmetrical with respect to the substrate 11 and the first laminate 22 and the second laminate 24, respectively. The antireflective layer 41, the third laminate 42, the intermediate layer 43, and the fourth laminate 44 function to suppress warping of the substrate 11.

[0052] The third stack 42, the intermediate layer 43, and the fourth stack 44 are formed to be thinner along the outer edge of the outer edge portion 11c. That is, the portion of the third stack 42, the intermediate layer 43, and the fourth stack 44 along the outer edge of the outer edge portion 11c is thinner than the other portions of the third stack 42, the intermediate layer 43, and the fourth stack 44 except for the portions along the outer edge. In the Fabry-Perot interference filter 1, the portion of the third stack 42, the intermediate layer 43, and the fourth stack 44 that overlaps with the thinned portion 83b described later when viewed from above is formed to be thinner by removing all of the third stack 42, the intermediate layer 43, and the fourth stack 44.

[0053] An opening 40a is formed in the third layer 42, the intermediate layer 43, and the fourth layer 44, overlapping the light-transmitting region 1a when viewed from above. The opening 40a has a diameter approximately the same as that of the light-transmitting region 1a. The opening 40a is located on the light-emitting side. The bottom surface of the opening 40a reaches the anti-reflective layer 41.

[0054] A light-shielding layer 45 is formed on the light-emitting side of the fourth laminate 44. The light-shielding layer 45 is made of a metal film, such as aluminum or its alloy. A protective layer 46 is formed on the surface of the light-shielding layer 45 and the inner surface of the opening 40a. The protective layer 46 covers the outer edge of the third laminate 42, the intermediate layer 43, the fourth laminate 44, and the light-shielding layer 45, and also covers the anti-reflective layer 41 on the outer edge 11c. The protective layer 46 is made of aluminum oxide, for example. Furthermore, by making the thickness of the protective layer 46 1 nm to 100 nm (preferably about 30 nm), the optical influence of the protective layer 46 can be ignored.

[0055] In the Fabry-Perot interferometer filter 1 configured as described above, when a voltage is applied between the driving electrodes 12 and 14 via terminals 15 and 16, an electrostatic force corresponding to the voltage is generated between the driving electrodes 12 and 14. This electrostatic force attracts the second mirror portion 32 to the side of the first mirror portion 31 fixed to the substrate 11, allowing adjustment of the distance between the first mirror portion 31 and the second mirror portion 32. Thus, in the Fabry-Perot interferometer filter 1, the distance between the first mirror portion 31 and the second mirror portion 32 can be changed.

[0056] The wavelength of light passing through the Fabry-Perot interferometer filter 1 depends on the distance between the first reflecting mirror portion 31 and the second reflecting mirror portion 32 in the light-transmitting region 1a. Therefore, by adjusting the voltage applied between the driving electrodes 12 and 14, the wavelength of the transmitted light (transmitted light) can be appropriately selected. Here, the compensation electrode 13 and the driving electrode 14 are at the same potential. Therefore, the compensation electrode 13 functions to keep the first reflecting mirror portion 31 and the second reflecting mirror portion 32 flat in the light-transmitting region 1a.

[0057] In the Fabry-Perot interferometer filter 1, for example, while changing the voltage applied to the Fabry-Perot interferometer filter 1 (i.e., while changing the distance between the first mirror section 31 and the second mirror section 32), the light passing through the light-transmitting region 1a of the Fabry-Perot interferometer filter 1 is detected by a photodetector, thereby obtaining a spectroscopic spectrum.

[0058] [Detailed Structure of Each Department]

[0059] Figure 4 This is an enlarged cross-sectional view showing a portion of the Fabry-Perot interference filter. Hereinafter, the view will be shown relative to the side where the first laminate 22 of the substrate 11 is located ( Figure 4 The upper side of the middle) is used as the upper side, and the side relative to the substrate 11 of the first laminate 22 is used as the upper side. Figure 4 The term "bottom side" is used in the description, but these terms do not limit the usage of the Fabry-Perot interference filter 1. For example, the Fabry-Perot interference filter 1 can also be used with the first laminate 22 located vertically below the substrate 11.

[0060] like Figure 4 As shown, in the first stack 22, a polysilicon layer 51 (third low-resistivity layer), a silicon nitride layer 61 (second insulating layer), a polysilicon layer 52 (first low-resistivity layer), a silicon nitride layer 62 (first insulating layer), and a polysilicon layer 53 (second low-resistivity layer) are sequentially disposed on the first surface 11a of the substrate 11 from the bottom side. That is, the polysilicon layer 51 (third low-resistivity layer) is disposed below the polysilicon layer 52 (first low-resistivity layer), and the polysilicon layer 53 (second low-resistivity layer) is disposed above the polysilicon layer 52. The silicon nitride layer 61 (second insulating layer) is disposed between the polysilicon layers 51 and 52, and the silicon nitride layer 62 (first insulating layer) is disposed between the polysilicon layers 52 and 53.

[0061] The silicon nitride layer 62 has a main body portion 62a (first main body portion), a cover portion 62b (first cover portion), and a peripheral portion 62c (first peripheral portion). The main body portion 62a, the cover portion 62b, and the peripheral portion 62c are integrally formed in a continuous manner. The main body portion 62a is located on the polysilicon layer 52 and overlaps with the entire polysilicon layer 52 when viewed from above. The cover portion 62b is continuous with the main body portion 62a on the outer edge 52c of the polysilicon layer 52. The cover portion 62b covers the outer edge 52c of the polysilicon layer 52, the outer edge 61d of the silicon nitride layer 61, and the outer edge 51a of the polysilicon layer 51, and reaches the anti-reflective layer 21. The peripheral portion 62c is continuous with the end of the cover portion 62b on the substrate 11 side and extends outward from the cover portion 62b along the first surface 11a of the substrate 11 (in other words, on the side opposite to the center of the void S). The peripheral portion 62c is located on the outer side of the polysilicon layer 52 when viewed from above. The covering portion 62b and the peripheral portion 62c are formed in a frame shape (a rectangular frame in this example) to surround the main body portion 62a when viewed from above. The width L1 of one side of the covering portion 62b and the peripheral portion 62c when viewed from above is, for example, about 2 μm. The width L1 is set to be, for example, about 4 to 200 times the thickness of the main body portion 62a (about 0.01 μm to 0.5 μm in this example).

[0062] The polysilicon layer 53 has a main body portion 53a, a cover portion 53b, and a peripheral portion 53c. The main body portion 53a, the cover portion 53b, and the peripheral portion 53c are integrally formed in a continuous manner. The main body portion 53a is located on the silicon nitride layer 62 and overlaps with the entire main body portion 62a of the silicon nitride layer 62 when viewed from above. The cover portion 53b covers the cover portion 62b and the peripheral portion 62c of the silicon nitride layer 62 and reaches the anti-reflective layer 21. The peripheral portion 53c is continuous with the end of the cover portion 53b on the substrate 11 side and extends outward from the cover portion 53b along the first surface 11a of the substrate 11. When viewed from above, the peripheral portion 53c is located outside the silicon nitride layer 62. The cover portion 53b and the peripheral portion 53c are formed in a frame shape (in this example, a rectangular frame shape) such that they surround the main body portion 53a when viewed from above. When viewed from above, the width L2 of one side of the covering portion 53b and the peripheral portion 53c is, for example, about 4 μm. The width L2 is set to be, for example, about 8 to 400 times the thickness of the main body portion 53a (in this example, about 0.01 μm to 0.5 μm). In addition, at the outer edge of the first laminate 22, a stepped portion 22a is formed by the peripheral portion 62c of the silicon nitride layer 62 and the peripheral portion 53c of the polysilicon layer 53.

[0063] The intermediate layer 23 has a defining portion 71 (third main body portion), a covering portion 72 (third covering portion), and an extension portion 73 (third peripheral portion). The defining portion 71, the covering portion 72, and the extension portion 73 are integrally formed in a continuous manner. The defining portion 71 defines a gap S between the first laminate 22 and the second laminate 24. When viewed from above, the defining portion 71 overlaps with both the first laminate 22 and the second laminate 24. That is, the defining portion 71 is located on the first laminate 22.

[0064] The cover portion 72 surrounds the defining portion 71 when viewed from above. The cover portion 72 is, for example, rectangular in shape when viewed from above. The cover portion 72 covers the outer edge 21a of the anti-reflective layer 21 and the outer edge of the first laminate 22, reaching the first surface 11a. That is, the cover portion 72 covers the outer edges of all layers constituting the first laminate 22, namely the outer edges 51a, 52c, and 53d of the polysilicon layers 51, 52, and 53, and the outer edges 61d and 62d of the silicon nitride layers 61 and 62.

[0065] The extension 73 surrounds the cover 72 when viewed from above. The extension 73 is, for example, rectangular in shape when viewed from above. The extension 73 extends outward from the cover 72 in a direction parallel to the first surface 11a (in other words, on the side opposite to the center of the gap S). The extension 73 is located outward from the first laminate 22 when viewed from above.

[0066] In addition to the second reflector portion 32, the second laminate 24 also includes a main body portion 81 (fourth main body portion), a cover portion 82 (fourth cover portion), and a peripheral portion 83 (fourth peripheral portion). The second reflector portion 32, the main body portion 81, the cover portion 82, and the peripheral portion 83 are integrally formed in a manner that has a portion of the same laminate structure and is continuous with each other. The second laminate 24 extends to the outer edge of the substrate 11 by covering the outer end face 72a of the cover portion 72 and the outer end face 73a of the extension portion 73 with the cover portion 82.

[0067] The main body 81 is located on the defining portion 71 of the intermediate layer 23 and overlaps with the entire defining portion 71 when viewed from above. The covering portion 82 surrounds the main body 81 when viewed from above. The covering portion 82 is, for example, rectangular in shape when viewed from above. The covering portion 82 covers the outer end face 73a of the extension portion 73.

[0068] Peripheral portion 83 surrounds cover portion 82 when viewed from above. Peripheral portion 83 is located outside the intermediate layer 23 when viewed from above. Peripheral portion 83 is, for example, rectangular frame-shaped when viewed from above. Peripheral portion 83 is located on the first surface 11a of outer edge portion 11c. The outer edge of peripheral portion 83 coincides with the outer edge of substrate 11 when viewed from above. Peripheral portion 83 is formed thinner (thinned) along the outer edge of outer edge portion 11c. That is, the portion of peripheral portion 83 along the outer edge of outer edge portion 11c is thinner than the other portions of peripheral portion 83 other than the portion along the outer edge. In this example, peripheral portion 83 is formed thinner by removing a portion of polysilicon layers 55, 56 and silicon nitride layers 64, 65 constituting the second laminate 24. Peripheral portion 83 has a non-thinned portion 83a continuous with cover portion 82 and a thinned portion 83b surrounding non-thinned portion 83a (see reference). Figure 1 In the thinning section 83b, the polysilicon layers 55 and 56, and the silicon nitride layers 64 and 65, other than the polysilicon layer 54 directly disposed on the first surface 11a, are removed.

[0069] [Functions and Effects]

[0070] As explained above, in the Fabry-Perot interferometer filter 1, in the first laminate 22 (refer to the laminate), the silicon nitride layer 62 (first insulating layer) has: a main body portion 62a (first main body portion) located on the polysilicon layer 52 (first low-resistance layer), a cover portion 62b (first cover portion) covering the outer edge 52c of the polysilicon layer 52, and a peripheral portion 62c (first peripheral portion) located outside the polysilicon layer 52 when viewed from above. The main body portion 62a, the cover portion 62b, and the peripheral portion 62c are integrally formed. Thus, by utilizing the cover portion 62b and the peripheral portion 62c of the silicon nitride layer 62, it is possible to prevent the polysilicon layer 53 (second low-resistance layer) from contacting the polysilicon layer 52, and to suppress leakage paths caused by contact between the polysilicon layer 53 and the polysilicon layer 52. Therefore, according to the Fabry-Perot interference filter 1, the distance between the first reflecting mirror 31 and the second reflecting mirror 32 can be adjusted with good precision.

[0071] In the Fabry-Perot interferometer filter 1, the first stack 22 includes: a polysilicon layer 51 (third low-resistivity layer) disposed on the substrate 11 side relative to the polysilicon layer 52, and a silicon nitride layer 61 (second insulating layer) disposed between the polysilicon layer 51 and the polysilicon layer 52. The resistivity of the material constituting the polysilicon layer 51 is less than the resistivity of the material constituting the silicon nitride layer 61. With this structure, the distance between the first reflector portion 31 and the second reflector portion 32 can be adjusted with good precision.

[0072] In the Fabry-Perot interferometer filter 1, the cover portion 62b (first cover portion) covers the outer edge 52c of the polysilicon layer 52 (first low-resistance layer), the outer edge 61d of the silicon nitride layer 61 (second insulating layer), and the outer edge 51a of the polysilicon layer 51 (third low-resistance layer). Therefore, in addition to preventing contact between the polysilicon layer 53 and the polysilicon layer 52, it also prevents contact between the polysilicon layer 52 and the polysilicon layer 51, further suppressing the generation of leakage paths.

[0073] In the Fabry-Perot interferometer filter 1, the polysilicon layer 53 (second low-resistance layer) extends in a manner that covers a portion 62b (first cover) of the silicon nitride layer 62 (first insulating layer). This allows for a smoother step portion 22a formed on the first laminate 22 compared to a case where the polysilicon layer 53 is formed only to cover the main body 62a of the silicon nitride layer 62. By making the step portion 22a formed on the first laminate 22 smoother, for example, uneven coating during the application of resist for etching can be suppressed, thus improving manufacturing stability. As a result, a decrease in yield can be suppressed.

[0074] In the Fabry-Perot interferometer filter 1, the polysilicon layer 52 (first low-resistance layer) is electrically connected to the compensation electrode 13 and the driving electrode 14. The polysilicon layer 53 (second low-resistance layer) is electrically connected to the driving electrode 12. In this structure, suppressing the formation of leakage paths between the polysilicon layers 52 and 53 becomes particularly important, and according to the Fabry-Perot interferometer filter 1, as described above, leakage paths generated due to the contact between the polysilicon layers 52 and 53 can be suppressed.

[0075] In the Fabry-Perot interferometer filter 1, the intermediate layer 23 has: a defining portion 71 (third main body portion) located on the first laminate 22, a covering portion 72 (third covering portion) covering the outer edge of the first laminate 22, and an extension portion 73 (third peripheral portion) located outside the first laminate 22 when viewed from above. The defining portion 71, the covering portion 72, and the extension portion 73 are integrally formed. As a result, because the outer edge of the first laminate 22 is covered by the intermediate layer 23, peeling of the first laminate 22 can be suppressed.

[0076] In the Fabry-Perot interferometer filter 1, the second laminate 24 has: a main body portion 81 (fourth main body portion) located on the intermediate layer 23, a covering portion 82 (fourth covering portion) covering the outer end face 73a of the intermediate layer 23, and a peripheral portion 83 (fourth peripheral portion) located on the outer side of the intermediate layer 23 when viewed from above. The main body portion 81, the covering portion 82, and the peripheral portion 83 are integrally formed. As a result, since the outer end face 73a of the intermediate layer 23 is covered by the second laminate 24, the peeling of the first laminate 22 and the intermediate layer 23 can be suppressed.

[0077] In the Fabry-Perot interferometer filter 1, polysilicon layer 52 (first low-resistance layer) and polysilicon layer 53 (second low-resistance layer) are formed of polysilicon, and silicon nitride layer 62 (first insulating layer) is formed of silicon nitride. This enables the achievement of the required mirror characteristics.

[0078] [First Variation]

[0079] The above describes one embodiment of the present invention, but the present invention is not limited to the above embodiment. Figure 5 This is an enlarged cross-sectional view showing a portion of the Fabry-Perot interferometer filter of the first modified example. The difference between the Fabry-Perot interferometer filter 101 of the first modified example and the Fabry-Perot interferometer filter 1 of the above-described embodiment is that the silicon nitride layer 61 covers the outer edge 51a of the polysilicon layer 51. In the first laminate 22 of the first modified example, the polysilicon layer 51 corresponds to the first low-resistance layer instead of the third low-resistance layer. In this case, the silicon nitride layer 61 corresponds to the first insulating layer, the polysilicon layer 52 corresponds to the second low-resistance layer, the silicon nitride layer 62 corresponds to the third insulating layer, and the polysilicon layer 53 corresponds to the fourth low-resistance layer.

[0080] In the first modified example, the silicon nitride layer 61 has a main body portion 61a (first main body portion), a cover portion 61b (first cover portion), and a peripheral portion 61c (first peripheral portion). The main body portion 61a, the cover portion 61b, and the peripheral portion 61c are integrally formed in a continuous manner. The main body portion 61a is located on the polysilicon layer 51 and overlaps with the entire polysilicon layer 51 when viewed from above. The cover portion 61b is continuous with the main body portion 61a at the outer edge 51a of the polysilicon layer 51. The cover portion 61b covers the outer edge 51a of the polysilicon layer 51 and reaches the anti-reflective layer 21. The peripheral portion 61c is continuous with the substrate 11 side end of the cover portion 61b and extends outward from the cover portion 61b along the first surface 11a of the substrate 11. When viewed from above, the peripheral portion 61c is located at a position further outward than the polysilicon layer 51. The covering portion 61b and the peripheral portion 61c are formed in a frame shape (in this example, a rectangular frame shape) to surround the main body portion 61a when viewed from above. The width L11 of one side of the covering portion 61b and the peripheral portion 61c when viewed from above is, for example, about 2 μm. The width L11 is set to, for example, about 4 to 200 times the thickness of the main body portion 61a (in this example, about 0.01 μm to 0.5 μm).

[0081] The polysilicon layer 52 has a main body portion 52a and a cover portion 52b. The main body portion 52a and the cover portion 52b are integrally formed in a continuous manner. The main body portion 52a is located on the main body portion 61a of the silicon nitride layer 61 and overlaps with the entire main body portion 61a when viewed from above. The cover portion 52b extends outward from the main body portion 52a along the first surface 11a of the substrate 11. The cover portion 52b covers the cover portion 61b of the silicon nitride layer 61 and is located on the peripheral portion 61c, overlapping with the peripheral portion 61c when viewed from above.

[0082] In the silicon nitride layer 62 of the first modified example, the main body portion 62a corresponds to the second main body portion, the cover portion 62b corresponds to the second cover portion, and the peripheral portion 62c corresponds to the second peripheral portion. The peripheral portion 62c is in contact with the peripheral portion 61c. The width L12 of one side of the cover portion 62b and the peripheral portion 62c when viewed from above is, for example, about 6 μm. The width L12 is set to, for example, about 12 to 600 times the thickness of the main body portion 62a (about 0.01 μm to 0.5 μm in this example).

[0083] The polysilicon layer 53 extends over the silicon nitride layer 62. In the polysilicon layer 53, when viewed from above, the width L13 of one edge of the covering portion 53b and the peripheral portion 53c is, for example, about 8 μm. The width L13 is set to, for example, about 16 to 800 times the thickness of the main body portion 53a (in this example, about 0.01 μm to 0.5 μm). Furthermore, at the outer edge of the first laminate 22, a stepped portion 22a is formed by the peripheral portion 61c of the silicon nitride layer 61, the covering portion 62b and the peripheral portion 62c of the silicon nitride layer 62, and the covering portion 53b and the peripheral portion 53c of the polysilicon layer 53.

[0084] The Fabry-Perot interference filter 101 of the first variant, like the Fabry-Perot interference filter 1 of the above embodiment, can also adjust the distance between the first mirror section 31 and the second mirror section 32 with good precision.

[0085] Furthermore, in the Fabry-Perot interferometer filter 101, the silicon nitride layer 62 (third insulating layer) has: a main body portion 62a (second main body portion) located on the polysilicon layer 52, a cover portion 62b (second cover portion) covering the outer edge 52c of the polysilicon layer 52, and a peripheral portion 62c (second peripheral portion) located on the outer side of the polysilicon layer 52 when viewed from above. The main body portion 62a, the cover portion 62b, and the peripheral portion 62c are integrally formed. As a result, for example, it is possible to prevent the polysilicon layer 53 stacked on the silicon nitride layer 62 from contacting the polysilicon layer 52, and the generation of leakage paths can be further suppressed.

[0086] Furthermore, in the Fabry-Perot interferometer filter 101, the peripheral portion 62c contacts the peripheral portion 61c. This further reliably prevents contact between the polysilicon layers 52 and 53, and further suppresses the generation of leakage paths.

[0087] Furthermore, in the Fabry-Perot interferometer filter 101, the polysilicon layer 53 (fourth low-resistance layer) is disposed on the side of the silicon nitride layer 62 opposite to the substrate. In this case, by utilizing the cover portion 62b and the peripheral portion 62c of the silicon nitride layer 62, it is possible to prevent the polysilicon layer 53 from contacting the polysilicon layer 52.

[0088] Furthermore, in the Fabry-Perot interferometer filter 101, the polysilicon layer 53 extends to cover the silicon nitride layer 62. This allows the step portion 22a formed in the first laminate 22 to be smooth. By making the step portion 22a formed in the first laminate 22 smooth, for example, uneven coating during the application of resist for etching can be suppressed, thereby improving manufacturing stability.

[0089] In the Fabry-Perot interferometer filter 101, the polysilicon layer 52 (the second low-resistance layer) is electrically connected to the compensation electrode 13 and the driving electrode 14. In such a structure, suppressing the formation of leakage paths between the polysilicon layers 51 and 52 is also important. For example, if a leakage path is formed between the polysilicon layers 51 and 52, the compensation electrode 13 and the driving electrode 14 will become conductive with the polysilicon layer 51. In this case, the size of the conductive area of ​​the compensation electrode 13 and the driving electrode 14 in the Fabry-Perot interferometer filter 101 becomes larger than intended, which may reduce the accuracy of controlling the distance between the first reflector section 31 and the second reflector section 32 by applying voltage to the driving electrode 12 and the driving electrode 14. According to the Fabry-Perot interferometer filter 101, as described above, the formation of leakage paths caused by the contact between the polysilicon layers 51 and 52 can be suppressed, thus preventing such an event from occurring.

[0090] [Second variation]

[0091] Figure 6 This is an enlarged cross-sectional view showing a portion of the Fabry-Perot interferometer filter of the second modification. The difference between the Fabry-Perot interferometer filter 201 of the second modification and the Fabry-Perot interferometer filter 101 of the first modification is that the peripheral portion 62c does not contact the peripheral portion 61c.

[0092] In the Fabry-Perot interferometer filter 201, the polysilicon layer 52 has a main body portion 52a, a cover portion 52b, and a peripheral portion 52d. The main body portion 52a, the cover portion 52b, and the peripheral portion 52d are integrally formed in a continuous manner. The main body portion 52a is located on the main body portion 61a of the silicon nitride layer 61 and overlaps with the entire main body portion 61a when viewed from above. The cover portion 52b covers the cover portion 61b and the peripheral portion 61c of the silicon nitride layer 61 and reaches the anti-reflective layer 21. The peripheral portion 52d is continuous with the end of the cover portion 52b on the substrate 11 side and extends outward from the cover portion 52b along the first surface 11a of the substrate 11. When viewed from a direction perpendicular to the first surface 11a, the peripheral portion 52d is located outward from the main body portion 61a and the cover portion 61b of the silicon nitride layer 61. The peripheral portion 52d is located between the peripheral portion 62c of the silicon nitride layer 62 and the peripheral portion 61c of the silicon nitride layer 61. Therefore, unlike the first modified example, the peripheral portion 62c does not contact the peripheral portion 61c.

[0093] The Fabry-Perot interference filter 201 according to the second variation can also adjust the distance between the first mirror section 31 and the second mirror section 32 with good precision, similar to the Fabry-Perot interference filter 1 of the above embodiment.

[0094] [Third variation]

[0095] Figure 7 This is an enlarged cross-sectional view showing a portion of the Fabry-Perot interferometer filter of the third modification. The Fabry-Perot interferometer filter 301 of the third modification differs from the Fabry-Perot interferometer filter 1 of the above embodiment in that it has a second stack 124, which has the same structure as the first stack 22 applied to the edge, instead of the second stack 24. In the second stack 124, a polysilicon layer 54, a silicon nitride layer 64, a polysilicon layer 55 (fifth low-resistance layer), a silicon nitride layer 65 (fourth insulating layer), and a polysilicon layer 56 (sixth low-resistance layer) are sequentially stacked from the bottom on the intermediate layer 23 and the first surface 11a of the substrate 11. That is, the polysilicon layer 55 (fifth low-resistance layer) is disposed above the polysilicon layer 54. The polysilicon layer 56 (sixth low-resistance layer) is disposed above the polysilicon layer 55 (fifth low-resistance layer). A silicon nitride layer 64 is disposed between a polysilicon layer 54 and a polysilicon layer 55 (the fifth low-resistance layer). A silicon nitride layer 65 (the fourth insulating layer) is disposed between a polysilicon layer 55 (the fifth low-resistance layer) and a polysilicon layer 56 (the sixth low-resistance layer).

[0096] The silicon nitride layer 65 has a main body portion 65a (fifth main body portion), a cover portion 65b (fifth cover portion), and a peripheral portion 65c (fifth peripheral portion). The main body portion 65a, the cover portion 65b, and the peripheral portion 65c are integrally formed in a continuous manner. The main body portion 65a is located on the polysilicon layer 55 and overlaps with the entire polysilicon layer 55 when viewed from above. The cover portion 65b is continuous with the main body portion 65a at the outer edge 55a of the polysilicon layer 55. The cover portion 65b covers the outer edge 55a of the polysilicon layer 55, the outer edge 64a of the silicon nitride layer 64, and the outer edge 54a of the polysilicon layer 54, and reaches the first surface 11a. The peripheral portion 65c is continuous with the end of the cover portion 65b on the substrate 11 side and extends outward from the cover portion 65b along the first surface 11a of the substrate 11. When viewed from above, the peripheral portion 65c is located at a position further outward than the polysilicon layer 55.

[0097] The polysilicon layer 56 has a main body portion 56a, a cover portion 56b, and a peripheral portion 56c. The main body portion 56a, the cover portion 56b, and the peripheral portion 56c are integrally formed in a continuous manner. The main body portion 56a is located on the silicon nitride layer 65 and overlaps with the main body portion 65a of the silicon nitride layer 65 when viewed from above. The cover portion 56b covers the cover portion 65b and the peripheral portion 65c and reaches the first surface 11a. The peripheral portion 56c is continuous with the end of the cover portion 56b on the substrate 11 side and extends outward from the cover portion 56b along the first surface 11a of the substrate 11. When viewed from above, the peripheral portion 56c is located outside the silicon nitride layer 65. The peripheral portion 56c is located on the first surface 11a of the outer edge portion 11c. When viewed from above, the outer edge of the peripheral portion 56c coincides with the outer edge of the substrate 11. A polysilicon layer 56 covers the main body portion 65a, the cover portion 65b, and the peripheral portion 65c. The cover portion 56b and the peripheral portion 56c are formed in a frame shape (in this example, a rectangular frame shape) so as to surround the main body portion 56a when viewed from above. Furthermore, a stepped portion 24c is formed by the peripheral portion 65c of the silicon nitride layer 65, the cover portion 56b, and the peripheral portion 56c of the polysilicon layer 56.

[0098] The Fabry-Perot interferometer filter 301 according to the third modification, like the Fabry-Perot interferometer filter 1 of the above embodiment, can adjust the distance between the first reflector portion 31 and the second reflector portion 32 with good precision. Furthermore, in the Fabry-Perot interferometer filter 301, the covering portion 65b (fifth covering portion) and the peripheral portion 65c (fifth peripheral portion) of the silicon nitride layer 65 (fourth insulating layer) can prevent contact between the polysilicon layer 55 and the polysilicon layer 56, and can suppress leakage paths caused by contact between the polysilicon layer 56 and the polysilicon layer 55.

[0099] This invention is not limited to the embodiments and variations described above. For example, the materials and shapes of the structures are not limited to those described above, and various materials and shapes can be used.

[0100] In the description of the third variation above, the first laminate 22 was described as a reference laminate, but the second laminate 124 can also be considered as a reference laminate. In this case, the second laminate 124 has: a polysilicon layer 55 (first low-resistivity layer), a polysilicon layer 56 (second low-resistivity layer) disposed on the upper side of the polysilicon layer 55, and a silicon nitride layer 65 (first insulating layer) disposed between the polysilicon layer 55 and the polysilicon layer 56. The resistivity of the materials constituting the polysilicon layer 55 and the polysilicon layer 56 is less than the resistivity of the material constituting the silicon nitride layer 65. The silicon nitride layer 65 has: a main body portion 65a (first main body portion) located on the polysilicon layer 55, a covering portion 65b (first covering portion) covering the outer edge 55a of the polysilicon layer 55, and a peripheral portion 65c (first peripheral portion) located on the outer side of the polysilicon layer 55 when viewed from above. The main body 65a, the cover portion 65b, and the peripheral portion 65c are integrally formed. Furthermore, the first laminate 22 has a polysilicon layer 52 (fifth low-resistivity layer), a polysilicon layer 53 (sixth low-resistivity layer) disposed above the polysilicon layer 52, and a silicon nitride layer 62 (fourth insulating layer) disposed between the polysilicon layers 52 and 53. The resistivity of the materials constituting the polysilicon layers 52 and 53 is less than the resistivity of the material constituting the silicon nitride layer 62. The silicon nitride layer 62 has: a main body 62a (fifth main body) located on the polysilicon layer 52, a cover portion 62b (fifth cover portion) covering the outer edge of the polysilicon layer 52, and a peripheral portion 62c (fifth peripheral portion) located further outward than the polysilicon layer 52 when viewed from above. The main body 62a, the cover portion 62b, and the peripheral portion 62c are integrally formed.

[0101] Furthermore, in the third variation, when the second stack 124 is considered as the reference stack, the silicon nitride layer 62 of the first stack 22 may not have a cover portion 62b and a peripheral portion 62c, and may only have a main body portion 62a. The polysilicon layer 53 of the first stack 22 may not have a cover portion 53b and a peripheral portion 53c, and may only have a main body portion 53a.

[0102] In the above embodiments and various modifications, the first laminate 22 may not have a polysilicon layer 51 and a silicon nitride layer 61, and may only have polysilicon layers 52 and 53 and a silicon nitride layer 62. Alternatively, the first laminate 22 may not have a polysilicon layer 53 and may only have polysilicon layers 51 and 52 and silicon nitride layers 61 and 62. The first laminate 22 may only have polysilicon layers 51 and 52 and a silicon nitride layer 61. The intermediate layer 23 may not have a covering portion 72 and an extension portion 73, and may only have a defining portion 71. The second laminate 24 may not have a covering portion 82 and a peripheral portion 83. The polysilicon layer 53 may not extend in a manner that covers the covering portion 62b of the silicon nitride layer 62, and may extend in a manner that covers only the main body portion 62a.

[0103] In the above embodiments and various modifications, the polysilicon layers 51, 52, and 53 may not be electrically connected to the compensation electrode 13 and the driving electrode 14. That is, the first low-resistance layer and the second low-resistance layer may also not be electrically connected to the electrodes. The compensation electrode 13 and the driving electrode 14 may also be formed in layers other than the polysilicon layer 53 (e.g., polysilicon layers 51 or 52).

[0104] In the above embodiments and various modifications, the low-resistivity layer of the first laminate 22 and the second laminate 24 is composed of a polycrystalline silicon layer 50, and the insulating layer is composed of a silicon nitride layer 60. However, the resistivity of the material constituting the low-resistivity layer only needs to be lower than the resistivity of the material constituting the insulating layer, and the materials constituting the low-resistivity layer and the insulating layer are not limited. For example, the low-resistivity layer of the first laminate 22 and the second laminate 24 can be a layer composed of aluminum, copper, titanium, chromium, cobalt, nickel, ruthenium, niobium, molybdenum, tungsten, gold, silver, carbon, etc., or it can be a layer composed of compounds containing them. The insulating layer of the first laminate 22 and the second laminate 24 can also be a layer composed of silicon oxide, titanium oxide, tantalum oxide, zirconium oxide, magnesium fluoride, aluminum oxide, calcium fluoride, silicon, germanium, zinc sulfide, etc.

[0105] In the above embodiment, the covering portion 62b can cover the outer edge 52c of the polysilicon layer 52, or it can leave the outer edge 61d of the silicon nitride layer 61 and the outer edge 51a of the polysilicon layer 51 uncovered.

[0106] Explanation of reference numerals in the attached figures

[0107] 1, 101, 201, 301…Fabry-Perot interference filter, 11…substrate, 22…first stack (refer to stack), 22a…step portion, 23…intermediate layer, 24, 124…second stack, 31…first reflector portion, 32…second reflector portion, S…gap, 51…polysilicon layer (third low-resistance layer) (first low-resistance layer), 51a…outer edge, 52…polysilicon layer (first low-resistance layer) (second low-resistance layer), 52c…outer edge, 53…polysilicon layer (second low-resistance layer) (fourth low-resistance layer), 55…polysilicon layer (fifth low-resistance layer), 56…polysilicon layer (sixth low-resistance layer), 61…silicon nitride layer (second insulating layer) (first insulating layer), 61a…main body portion (first main body portion), 61b…cover portion (first… 61c… Peripheral portion (first peripheral portion), 61d… Outer edge, 62… Silicon nitride layer (first insulating layer) (second insulating layer), 62a… Main body portion (first main body portion) (second main body portion), 62b… Cover portion (first cover portion) (second cover portion), 62c… Peripheral portion (first peripheral portion) (second peripheral portion), 65… Silicon nitride layer (fourth insulating layer), 65a… Main body portion (fifth main body portion), 65b… Cover portion (fifth cover portion), 65c… Peripheral portion (fifth peripheral portion), 71… Defining portion (third main body portion), 72… Cover portion (third cover portion), 73… Extension portion (third peripheral portion), 81… Main body portion (fourth main body portion), 82… Cover portion (fourth cover portion), 83… Peripheral portion (fourth peripheral portion), S… Gap.

Claims

1. A Fabry-Perot interference filter, characterized in that, include: substrate; The first laminate has a first reflective mirror portion disposed on the substrate; The second laminate has a second reflector portion, which is opposite to the first reflector portion on the side of the first reflector portion opposite to the substrate, separated by a gap; and An intermediate layer that defines the gap between the first and second laminates. A reference laminate serving as one of the first laminate and the second laminate includes: a first low-resistivity layer; and a second low-resistivity layer disposed on the side of the first low-resistivity layer opposite to the substrate. and a first insulating layer disposed between the first low-resistance layer and the second low-resistance layer, The resistivity of the materials constituting the first low-resistivity layer and the second low-resistivity layer is lower than the resistivity of the material constituting the first insulating layer. The first insulating layer has: a first main body portion located on the first low resistance layer; and a first covering portion covering the outer edge of the first low resistance layer; And the first peripheral portion located outside the first low-resistivity layer when viewed from a direction perpendicular to the substrate. The first main body, the first covering part, and the first peripheral part are integrally formed.

2. The Fabry-Perot interferometer filter as described in claim 1, characterized in that: The reference laminate includes: a third low-resistance layer disposed on the substrate side of the first low-resistance layer; and a second insulating layer disposed between the first low-resistance layer and the third low-resistance layer. The resistivity of the material constituting the third low-resistivity layer is less than the resistivity of the material constituting the second insulating layer.

3. The Fabry-Perot interferometer filter as described in claim 2, characterized in that: The first covering portion covers the outer edge of the first low-resistance layer, the outer edge of the third low-resistance layer, and the outer edge of the second insulating layer.

4. The Fabry-Perot interferometer filter as described in claim 2 or 3, characterized in that: The second low-resistance layer extends in a manner that covers the first covering portion of the first insulating layer.

5. The Fabry-Perot interferometer filter as described in claim 1, characterized in that: The reference laminate further comprises: a third insulating layer disposed on the side of the second low-resistivity layer opposite to the substrate. The third insulating layer has: a second main body portion located on the second low resistance layer; and a second covering portion covering the outer edge of the second low resistance layer; And the second peripheral portion located outside the second low-resistivity layer when viewed from a direction perpendicular to the substrate. The second main body, the second cover, and the second peripheral portion are integrally formed.

6. The Fabry-Perot interferometer filter as described in claim 5, characterized in that: The second peripheral portion contacts the first peripheral portion.

7. The Fabry-Perot interferometer filter as described in claim 5 or 6, characterized in that: The reference laminate further comprises a fourth low-resistance layer disposed on the side of the third insulating layer opposite to the substrate.

8. The Fabry-Perot interferometer filter as described in any one of claims 1 to 7, characterized in that: At least one of the first low-resistance layer and the second low-resistance layer is electrically connected to the electrode.

9. The Fabry-Perot interferometer filter as described in any one of claims 1 to 8, characterized in that: The intermediate layer has: a third main body portion located on the first laminate; a third cover portion covering the outer edge of the first laminate; and a third peripheral portion located on the outer side of the first laminate when viewed from a direction perpendicular to the substrate. The third main body, the third covering, and the third peripheral portion are integrally formed.

10. The Fabry-Perot interferometer filter as described in any one of claims 1 to 9, characterized in that: The reference laminate is the first laminate. The second laminate has: a fourth main body portion located on the intermediate layer; a fourth covering portion covering the outer edge of the intermediate layer; and a fourth peripheral portion located on the outer side of the intermediate layer when viewed from a direction perpendicular to the substrate. The fourth main body, the fourth covering, and the fourth peripheral portion are integrally formed.

11. The Fabry-Perot interferometer filter as described in any one of claims 1 to 10, characterized in that: The first low-resistance layer and the second low-resistance layer are formed of polycrystalline silicon. The first insulating layer is formed of silicon nitride.

12. The Fabry-Perot interferometer filter as described in any one of claims 1 to 11, characterized in that: The other of the first laminate and the second laminate has: a fifth low-resistance layer; and a sixth low-resistance layer disposed on the side of the fifth low-resistance layer opposite to the substrate; and a fourth insulating layer disposed between the fifth low-resistance layer and the sixth low-resistance layer, The resistivity of the materials constituting the fifth and sixth low-resistivity layers is less than the resistivity of the material constituting the fourth insulating layer. The fourth insulating layer has: a fifth main body portion located on the fifth low-resistivity layer; a fifth covering portion covering the outer edge of the fifth low-resistivity layer; and a fifth peripheral portion located outside the fifth low-resistivity layer when viewed from a direction perpendicular to the substrate. The fifth main body portion, the fifth covering portion, and the fifth peripheral portion are integrally formed.

13. The Fabry-Perot interferometer filter as described in any one of claims 1 to 12, characterized in that: The reference stack is the first stack.

14. The Fabry-Perot interferometer filter as described in any one of claims 1 to 12, characterized in that: The reference stack is the second stack.

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