Sensor

Abstract

To provide a sensor capable of obtaining high detection sensitivity.SOLUTION: According to the embodiment, a sensor includes a substrate, a fixed electrode, a first fixed section, a first support section, and a movable section. The substrate includes a first area and a second area. The fixed electrode is fixed to the first area. The first fixed section is fixed to the second area. The first support section is connected to the first fixed section. The first support section includes a first support layer, a first layer, and a second layer. The first layer is provided between the first support layer and at least one portion of the second layer in a first direction from the first support layer to the second layer. The first layer contains a first element containing at least one selected from a group comprising Pt, Pd, and Ti, and oxygen. The second layer contains a second element different from the first element, and oxygen. The movable section is supported by the first support section. A first gap is provided between the fixed electrode and the movable section.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present invention relates to a sensor. [Background technology]

[0002] For example, there are sensors that use MEMS structures, and high detection sensitivity is desired for such sensors. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-56607 A Summary of the Invention [Problem to be solved by the invention]

[0004] Embodiments of the present invention provide a sensor that provides high detection sensitivity. [Means for solving the problem]

[0005] According to an embodiment of the present invention, the sensor includes a base, a fixed electrode, a first fixed portion, a first support portion, and a movable portion. The base includes a first region and a second region. The fixed electrode is fixed to the first region. The first fixed portion is fixed to the second region. The first support portion is connected to the first fixed portion. The first support portion includes a first support layer, a first layer, and a second layer. In a first direction from the first support layer to the second layer, the first layer is provided between the first support layer and at least a part of the second layer. The first layer includes a first element including at least one selected from the group consisting of Pt, Pd, and Ti, and oxygen. The second layer includes a second element different from the first element, and oxygen. The movable portion is supported by the first support portion. A first gap is provided between the fixed electrode and the movable portion. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating the sensor according to the first embodiment. [Diagram 2] FIG. 2 is a graph illustrating the characteristics of the sensor. [Diagram 3] 3A and 3B are schematic cross-sectional views illustrating the operation of the sensor according to the first embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view illustrating a part of the sensor according to the first embodiment. [Diagram 5] FIG. 5 is a schematic cross-sectional view illustrating a part of the sensor according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing. In this specification and each drawing, elements similar to those described above with reference to the previous drawings are given the same reference numerals and detailed descriptions thereof will be omitted as appropriate.

[0008] (First embodiment) FIG. 1 is a schematic cross-sectional view illustrating the sensor according to the first embodiment. As shown in FIG. 1, a sensor 110 according to the embodiment includes a base 40, a fixed electrode 55, a first fixed portion 21, a first support portion 31s, and a movable portion 30M.

[0009] The substrate 40 includes a first region 41 and a second region 42. The substrate 40 may be, for example, a silicon substrate.

[0010] The fixed electrode 55 is fixed to the first region 41. On the fixed electrode 55, an insulating film 55a may be provided.

[0011] The first fixing portion 21 is fixed to the second region 42. The first support portion 31s is connected to the first fixing portion 21. The first support portion 31s includes a first support layer 31L, a first layer 31, and a second layer 32. The first layer 31 is fixed to the first support layer 31L. In a first direction D1 from the first support layer 31L to the second layer 32, the first layer 31 is provided between the first support layer 31L and at least a portion of the second layer 32.

[0012] The first layer 31 includes a first element including at least one selected from the group consisting of Pt, Pd, and Ti, and oxygen. For example, the first layer 31 includes an oxide of the first element. For example, the first layer 31 includes a bond between the first element and oxygen.

[0013] The second layer 32 includes a second element different from the first element and oxygen. In one example, the second element includes at least one selected from the group consisting of Si and Al. For example, the second layer 32 includes an oxide of the second element. For example, the second layer 32 includes a bond between the second element and oxygen.

[0014] The movable portion 30M is supported by a first support portion 31s. A first gap G1 is provided between the fixed electrode 55 and the movable portion 30M.

[0015] For example, the first layer 31 is reduced by the target gas around the first support portion 31s. At least a portion of the oxide of the first element contained in the first layer 31 is reduced. The target gas includes, for example, hydrogen. When the first layer 31 is reduced, for example, oxygen contained in the first layer 31 is released from the first layer 31. The structure of the first layer 31 changes. For example, the volume of the first layer 31 changes.

[0016] Due to the change in the structure of the first layer 31, stress is generated between the first layer 31 and the first support layer 31L. The stress is, for example, tensile stress. For example, the first layer 31 tries to shrink with respect to the first support layer 31L. This causes a change in the shape of the first support portion 31s. The change in shape changes the distance between the movable portion 30M and the fixed electrode 55. The capacitance changes in response to the change in distance. The target gas can be detected by detecting the change in capacitance.

[0017] In the embodiment, the above-mentioned second layer 32 is provided. It has been found that this provides higher detection sensitivity.

[0018] FIG. 2 is a graph illustrating the characteristics of the sensor. The horizontal axis of Figure 2 is the concentration parameter CP1. The concentration parameter CP1 is the 1 / 2 power of the concentration of the target gas. An increase in the concentration parameter CP1 corresponds to an increase in the concentration of the target gas. The vertical axis is the change in capacitance ΔC. The change ΔC is based on the capacitance when the concentration of the target gas is 0. A negative change ΔC corresponds to a decrease in capacitance.

[0019] FIG. 2 shows the characteristics of the sensor 110 according to the embodiment and the characteristics of the sensor 119 of the first reference example.

[0020] 2, when the concentration parameter CP1 increases, the capacitance change ΔC is negative and the absolute value of the change ΔC increases. That is, when the concentration of the detection target gas increases, the capacitance decreases.

[0021] 2, in sensor 110, the ratio (slope) of the change in the change ΔC relative to the change in the concentration parameter CP1 is higher than the ratio (slope) in sensor 119. In sensor 110, the detection target can be detected with high sensitivity.

[0022] In addition to the gas to be detected (e.g., a reducing gas), oxygen present in the air is present around the first support portion 31s. In the first reference example in which the second layer 32 is not provided, it is considered that oxygen is adsorbed to the first layer 31. In the first reference example, it is considered that reduction of the first layer 31 (first element) and desorption of the oxygen adsorbed to the first layer 31 occur simultaneously. The change in stress in the first support portion 31s in response to these phenomena is in the opposite direction. For this reason, it is difficult to sufficiently increase the sensitivity in the first reference example.

[0023] In contrast, the provision of the second layer 32 suppresses the effect of oxygen on the first layer 31. As a result, it is believed that high detection sensitivity can be obtained in the embodiment.

[0024] 3A and 3B are schematic cross-sectional views illustrating the operation of the sensor according to the first embodiment. In the second state ST2 shown in FIG. 3(a), the concentration of the gas to be detected (e.g., hydrogen) is low. In the second state ST2, the gas to be detected (e.g., hydrogen) is substantially absent. In the first state ST1 shown in FIG. 3(b), the gas to be detected (e.g., hydrogen) is present. In the first state ST1, the concentration of the gas to be detected (e.g., hydrogen) is higher than the concentration in the second state ST2.

[0025] 3(a), in the second state ST2, an oxide 31MO of the first element (for example, Pt oxide) is present in the first layer 31. Oxygen 81O in the air is adsorbed onto the surface of the second layer 32.

[0026] As shown in FIG. 3(b), in the first state ST1, the detection target gas 81H (e.g., hydrogen) passes through the second layer 32 and reaches the first layer 31. Reduction of the first element occurs in the first layer 31. The detection target gas 81H is in a molecular state (hydrogen molecules) on the surface of the second layer 32. Therefore, there is substantially no effect on the oxygen adsorbed on the surface of the second layer 32. Therefore, desorption of oxygen is suppressed. In the embodiment, by suppressing desorption of oxygen, the change due to reduction is efficiently utilized. According to the embodiment, a sensor with high detection sensitivity can be provided.

[0027] In the embodiment, the first element oxide is reduced while the desorption of the adsorbed oxygen is suppressed. This allows a highly sensitive response to minute changes in the detection target (e.g., hydrogen) in the atmosphere. For example, an ultra-sensitive hydrogen sensor can be obtained.

[0028] For example, the second layer 32 does not contain the first element. Alternatively, the concentration of the first element in the second layer 32 is lower than the concentration of the first element in the first layer 31.

[0029] For example, the first layer 31 does not contain the second element. Alternatively, the concentration of the second element in the first layer 31 is lower than the concentration of the second element in the second layer 32.

[0030] For example, the first element can be reduced by the target gas, and the second element is not substantially reduced by the target gas, hi one example, the target gas is hydrogen.

[0031] 1, the movable portion 30M may include a movable electrode 35. The capacitance may be the capacitance between the fixed electrode 55 and the movable electrode 35.

[0032] 2, the concentration of the target gas in the first state ST1 (high concentration) is higher than the concentration of the target gas in the second state ST2 (low concentration). A first capacitance between the fixed electrode 55 and the movable part 30M in the first state ST1 is smaller than a second capacitance between the fixed electrode 55 and the movable part 30M in the second state ST2.

[0033] In this way, the change in capacitance corresponds to the concentration of the target gas. The target gas can be detected by detecting the change in capacitance. For example, the target gas can be detected with high sensitivity of about 0.1 ppm to 1000 ppm.

[0034] 1, the sensor 110 may further include a control unit 70. The control unit 70 is capable of detecting capacitances (for example, a first capacitance and a second capacitance).

[0035] The change in capacitance corresponds to a change in the distance dz between the fixed electrode 55 and the movable part 30M (movable electrode 35). For example, a first distance between the fixed electrode 55 and the movable part 30M in the first state ST1 (high density) is longer than a second distance between the fixed electrode 55 and the movable part 30M in the second state ST2 (low density).

[0036] For example, a change in the distance dz may be detected. For example, the displacement of the movable part 30M may be detected by an optical method or the like.

[0037] As described above, the change in the distance dz may be based on a stress caused by a change in the volume of the first layer 31. For example, the first volume of the first layer 31 in the first state ST1 (high concentration) is smaller than the second volume of the first layer 31 in the second state ST2 (low concentration).

[0038] 1, in this example, the first support layer 31L is provided between the base 40 and the first layer 31. A second gap G2 is provided between the base 40 and the first support layer 31L.

[0039] In this example, the sensor 110 further includes a first connection portion 31c. A part of the first connection portion 31c is connected to the first support portion 31s. Another part of the first connection portion 31c is connected to the movable portion 30M. A third gap G3 is provided between the base 40 and the first connection portion 31c. For example, the first connection portion 31c may have a meandering structure.

[0040] As shown in FIG. 1, the sensor 110 may include a second fixing portion 22 and a second supporting portion 32s. The base 40 further includes a third region 43. The first region 41 is between the second region 42 and the third region 43. The second fixing portion 22 is fixed to the third region 43. The second supporting portion 32s is connected to the second fixing portion 22. The second supporting portion 32s includes a second supporting layer 32L, a third layer 33, and a fourth layer 34. The third layer 33 is fixed to the second supporting layer 32L. At least a portion of the third layer 33 is provided between the second supporting layer 32L and the fourth layer 34.

[0041] The third layer 33 includes a first element and oxygen. The fourth layer 34 includes a second element and oxygen. The third layer 33 includes, for example, an oxide of the first element. The third layer 33 includes, for example, a bond between the first element and oxygen. The fourth layer 34 includes, for example, an oxide of the second element. The fourth layer 34 includes, for example, a bond between the second element and oxygen.

[0042] For example, the fourth layer 34 does not contain the first element. Alternatively, the concentration of the first element in the fourth layer 34 is lower than the concentration of the first element in the third layer 33.

[0043] For example, the third layer 33 does not contain the second element. Alternatively, the concentration of the second element in the third layer 33 is lower than the concentration of the second element in the fourth layer .

[0044] The movable portion 30M is provided between the first support portion 31s and the second support portion 32s. The movable portion 30M is supported by the first support portion 31s and the second support portion 32s. A fourth gap G4 is provided between the base body 40 and the second support portion 32s. A double-supported beam structure may be applied.

[0045] In this example, the sensor 110 further includes a second connection portion 32c. A part of the second connection portion 32c is connected to the second support portion 32s. Another part of the second connection portion 32c is connected to the movable portion 30M. A fifth gap G5 is provided between the base 40 and the second connection portion 32c. The second connection portion 32c has, for example, a meandering structure.

[0046] 1, the first support portion 31s may include a first conductive member 31h. The second support portion 32s may include a second conductive member 32h. For example, the temperature of the first support portion 31s can be increased by a current flowing through the first conductive member 31h. For example, the temperature of the second support portion 32s can be increased by a current flowing through the second conductive member 32h. For example, by heating the support portion, various substances (including, for example, hydrogen) adsorbed to the first support portion 31s and the second support portion 32s are released.

[0047] The first layer 31 and the third layer 33 have a thickness of, for example, 1 nm or more and 1 μm or less. The second layer 32 and the fourth layer 34 have a thickness of, for example, 0.1 nm or more and 1 μm or less. The first support layer 31L and the second support layer 32L have a thickness of, for example, 10 nm or more and 10 μm or less. The thickness corresponds to the length along the first direction D1.

[0048] The first support layer 31L and the second support layer 32L include, for example, at least one selected from the group consisting of nitrogen and oxygen, and silicon. The first support layer 31L and the second support layer 32L may include silicon nitride or silicon oxide.

[0049] 4 and 5 are schematic cross-sectional views illustrating a part of the sensor according to the first embodiment. These figures illustrate the first support portion 31s. As shown in Fig. 4 and Fig. 5, in the sensors 111 and 112 according to the embodiment, the configuration of the first support portion 31s is different from that in the sensor 110. Except for this, the configurations of the sensors 111 and 112 may be similar to that of the sensor 110.

[0050] 4, in the sensor 111, the first layer 31 is provided between a plurality of regions included in the second layer 32 in a direction intersecting the first direction D1. For example, an upper surface of the first layer 31 is covered with the second layer 32. A side surface of the first layer 31 may be covered with the second layer 32. In the first layer 31, the effect of oxygen is more effectively suppressed.

[0051] 5, in the sensor 112, at least a portion of the first support layer 31L is provided between a portion of the second layer and the first layer 31 in the first direction D1. For example, the first support layer 31L and the first layer 31 may be provided between a plurality of regions included in the second layer 32 in the first direction D1.

[0052] In the sensors 111 and 112, the configuration of the first support portion 31s may be applied to the second support portion 32s.

[0053] There are resistance change type and semiconductor type hydrogen sensors, but these hydrogen sensors have limitations in terms of reducing power consumption.

[0054] In the embodiment, for example, the first layer 31 is reduced by the detection target gas (hydrogen). This causes the first support portion 31s including the first layer 31 to deform. The deformation of the first support portion 31s is detected as, for example, a change in capacitance.

[0055] In the embodiment, the first layer 31 (sensitive film) contains a metal oxide. The metal oxide has a catalytic effect. When a reducing gas such as hydrogen approaches the sensitive film, the film stress changes in the tensile stress direction. The concentration of oxygen in the sensitive film changes depending on the concentration (including the presence or absence) of the gas to be detected.

[0056] For example, when a reducing gas such as hydrogen approaches the sensitive film, hydrogen molecules dissociate into hydrogen atoms on the surface of the sensitive film. These hydrogen atoms reduce metal oxides, forming water and leaving the film. The frequency of this reaction depends on the hydrogen concentration. When the amount of oxygen in the sensitive film decreases, the film stress changes to the tensile direction.

[0057] In the embodiment, for example, the reduction action of a catalytic metal oxide is utilized. For example, the metal oxide is reduced by the reducing gas to be detected. This causes a change in the volume of the layer containing the catalytic metal. The change in volume is detected as a change in capacitance. By utilizing the reduction action, the concentration of a very small amount of reducing gas of about 0.1 ppm can be detected with high sensitivity.

[0058] The embodiments may include the following technical solutions. (Technical proposal 1) a substrate including a first region and a second region; a fixed electrode fixed to the first region; A first fixed portion fixed to the second region; a first support part connected to the first fixed part, the first support part including a first support layer, a first layer, and a second layer, the first layer being provided between the first support layer and at least a part of the second layer in a first direction from the first support layer to the second layer, the first layer including a first element including at least one selected from the group consisting of Pt, Pd, and Ti, and oxygen, and the second layer including a second element different from the first element and oxygen; a movable part supported by the first support part, the movable part having a first gap between the fixed electrode and the movable part; A sensor equipped with

[0059] (Technical proposal 2) The sensor described in Technical Solution 1, wherein the second element includes at least one selected from the group consisting of Si and Al.

[0060] (Technical proposal 3) The sensor described in Technical Solution 1 or 2, wherein the second layer does not contain the first element, or the concentration of the first element in the second layer is lower than the concentration of the first element in the first layer.

[0061] (Technical proposal 4) The sensor described in Technical Proposal 3, wherein the first layer does not contain the second element, or the concentration of the second element in the first layer is lower than the concentration of the second element in the second layer.

[0062] (Technical proposal 5) The sensor according to any one of Technical Solutions 1 to 4, wherein the first layer is provided between a plurality of regions included in the second layer in a direction intersecting the first direction.

[0063] (Technical proposal 6) The sensor according to any one of Technical Solutions 1 to 5, wherein at least a portion of the first support layer is provided between a portion of the second layer and the first layer in the first direction.

[0064] (Technical proposal 7) The sensor according to any one of Technical Schemes 1 to 6, wherein the first layer is reduced by the target gas around the first support portion.

[0065] (Technical proposal 8) The sensor according to Technical Proposal 7, wherein the detection target gas includes hydrogen.

[0066] (Technical proposal 9) The concentration of the detection target gas in the first state is higher than the concentration of the detection target gas in the second state, A sensor described in any one of technical proposals 1 to 6, wherein a first distance between the fixed electrode and the movable part in the first state is longer than a second distance between the fixed electrode and the movable part in the second state.

[0067] (Technical proposal 10) The concentration of the detection target gas in the first state is higher than the concentration of the detection target gas in the second state, The sensor according to any one of Technical Solutions 1 to 6, wherein a first volume of the first layer in the first state is smaller than a second volume of the first layer in the second state.

[0068] (Technical proposal 11) The concentration of the detection target gas in the first state is higher than the concentration of the detection target gas in the second state, A sensor described in any one of technical proposals 1 to 6, wherein a first electrical capacitance between the fixed electrode and the movable part in the first state is smaller than a second electrical capacitance between the fixed electrode and the movable part in the second state.

[0069] (Technical proposal 12) The sensor described in Technical Proposal 11 further includes a control unit capable of detecting the first capacitance and the second capacitance.

[0070] (Technical proposal 13) the first layer includes a bond between the first element and oxygen, The sensor according to any one of Technical Schemes 1 to 12, wherein the second layer includes a bond between the second element and oxygen.

[0071] (Technical proposal 14) The first support further includes a first conductive member, The sensor according to any one of Technical Solutions 1 to 13, wherein the temperature of the first support portion can be increased by a current flowing through the first conductive member.

[0072] (Technical proposal 15) The sensor according to any one of Technical Solutions 1 to 14, wherein the first support layer includes at least one selected from the group consisting of nitrogen and oxygen, and silicon.

[0073] (Technical proposal 16) the first support layer is disposed between the substrate and the first layer; The sensor according to any one of Technical Schemes 1 to 15, wherein a second gap is provided between the substrate and the first support layer.

[0074] (Technical proposal 17) Further comprising a first connection portion, a portion of the first connection portion is connected to the first support portion, Another part of the first connection part is connected to the movable part, The sensor described in Technical Proposal 16, wherein a third gap is provided between the base and the first connection portion.

[0075] (Technical proposal 18) A second fixing portion; A second support portion; Further equipped with The substrate further comprises a third region, the first region is between the second region and the third region, the second fixing portion is fixed to the third region, the second support portion is connected to the second fixed portion, the second support section includes a second support layer, a third layer fixed to the second support layer, and a fourth layer, at least a portion of the third layer is provided between the second support layer and the fourth layer, the third layer includes the first element and oxygen, and the fourth layer includes the second element and oxygen, The sensor according to any one of Technical Solutions 1 to 17, wherein the movable portion is provided between the first support portion and the second support portion and is further supported by the second support portion.

[0076] (Technical proposal 19) Further comprising a second connection portion, a portion of the second connection portion is connected to the second support portion, Another part of the second connection part is connected to the movable part, The sensor described in Technical Proposal 18, wherein a gap is provided between the base and the second connection portion.

[0077] (Technical proposal 20) The first layer has a thickness of 1 nm or more and 1 μm or less, The thickness of the second layer is 0.1 nm or more and 1 μm or less, 20. The sensor according to any one of Technical Schemes 1 to 19, wherein the first support layer has a thickness of 10 nm or more and 10 μm or less.

[0078] According to the embodiment, a sensor that can obtain high detection sensitivity can be provided.

[0079] The above describes the embodiment of the present invention with reference to examples. However, the present invention is not limited to these examples. For example, the specific configurations of each element included in the sensor, such as the base, fixed part, support part, layer, movable part, fixed electrode, and control part, are included in the scope of the present invention as long as a person skilled in the art can implement the present invention in the same way and obtain the same effect by appropriately selecting from the known range.

[0080] Any combination of two or more elements of each example, within the scope of technical feasibility, is also included within the scope of the present invention as long as it includes the gist of the present invention.

[0081] All sensors that can be implemented by a person skilled in the art by appropriately modifying the design based on the above-described sensor as an embodiment of the present invention are within the scope of the present invention as long as they include the gist of the present invention.

[0082] Within the scope of the concept of the present invention, a person skilled in the art may conceive of various modifications and alterations, and it is understood that these modifications and alterations also fall within the scope of the present invention.

[0083] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0084] 21, 22: first and second fixed portions, 30M: movable portion, 31-34: first to fourth layers, 31L, 32L: first and second support layers, 31MO: oxide, 31c, 32c: first and second connection portions, 31h, 32h: first and second conductive members, 31s, 32s: first and second support portions, 35: movable electrode, 40: base, 41-43: first to third regions, 55: fixed electrode, 55a: insulating film, 70: control portion, 81H: detection target gas, 81O: oxygen, 110-112: sensor, CP1: concentration parameter, D1: first direction, G1-G5: first to fifth gaps, ST1, ST2: first and second states, dz: distance, ΔC: change

Claims

1. a substrate including a first region and a second region; A fixed electrode fixed to the first region; A first fixing portion fixed to the second region; a first support part connected to the first fixed part, the first support part including a first support layer, a first layer, and a second layer, the first layer being provided between the first support layer and at least a part of the second layer in a first direction from the first support layer to the second layer, the first layer including a first element including at least one selected from the group consisting of Pt, Pd, and Ti, and oxygen, and the second layer including a second element different from the first element and oxygen; a movable portion supported by the first support portion, the movable portion having a first gap between the fixed electrode and the movable portion; A sensor equipped with

2. The sensor of claim 1 , wherein the second element includes at least one selected from the group consisting of Si and Al.

3. The sensor of claim 1 , wherein the second layer does not contain the first element, or the concentration of the first element in the second layer is lower than the concentration of the first element in the first layer.

4. The sensor according to claim 1 , wherein the first layer is provided between a plurality of regions included in the second layer in a direction intersecting the first direction.

5. The sensor of claim 1 , wherein at least a portion of the first support layer is disposed between a portion of the second layer and the first layer in the first direction.

6. The sensor according to claim 1 , wherein the first layer is reduced by a target gas around the first support portion.

7. The sensor according to claim 6 , wherein the detection target gas includes hydrogen.

8. The concentration of the detection target gas in the first state is higher than the concentration of the detection target gas in the second state, The sensor of any one of claims 1 to 5, wherein a first distance between the fixed electrode and the movable part in the first state is longer than a second distance between the fixed electrode and the movable part in the second state.

9. The concentration of the detection target gas in the first state is higher than the concentration of the detection target gas in the second state, The sensor of any one of claims 1 to 5, wherein a first electrical capacitance between the fixed electrode and the movable part in the first state is smaller than a second electrical capacitance between the fixed electrode and the movable part in the second state.

10. The first support portion further includes a first conductive member, The sensor according to claim 1 , wherein a temperature of the first support portion can be increased by a current flowing through the first conductive member.

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