Gas sensor

Abstract

A gas sensor 100 comprises a laminate 11 in which electrode layers 31, 32 and an insulation layer 24 are alternately laminated. The laminate 11 has an inclined surface 11C on at least a portion of a side surface, and the inclined surface 11C functions as a detection part for detecting a specific component of a measurement target gas.

Description

Gas Sensor

[0001] The present disclosure relates to gas sensors.

[0002] A conventional sensor technology is disclosed in Patent Document 1. Specifically, Patent Document 1 discloses a sensor in which a first Au layer is formed on a silicon substrate and an Al ２ O ３ By using the Al ２ O ３ The sensor has a nanogap with a thickness of 1000 nm. When a solution is injected into the nanogap, the sensor can detect a specific substance through a change in the electrical properties at both ends of the nanogap.

[0003] Japanese Patent Application Laid-Open No. 2006-234799

[0004] It is desirable to improve the detection sensitivity of a specific substance in the configuration disclosed in Patent Document 1. However, in the past, no study was made on the structure of the electrode layer of the sensor in order to improve the detection sensitivity of a specific substance.

[0005] The present disclosure is a technology completed based on the above circumstances, and one of its objects is to provide a gas sensor that can improve detection sensitivity.

[0006] The gas sensor of the present disclosure is a gas sensor comprising a laminate in which electrode layers and insulating layers are alternately stacked, and the laminate has an inclined surface on at least a portion of its side surface, and the inclined surface functions as a detection portion that detects a specific component of the measured gas.

[0007] According to the present disclosure, it is possible to provide a gas sensor that can improve detection sensitivity.

[0008] FIG. 1 is a schematic plan view of a gas sensor device according to a first embodiment; FIG. 2 is a diagram showing a cross-sectional configuration of a portion of a gas sensor; FIG. 3 is an enlarged cross-sectional view of the vicinity of an inclined surface of a laminate; FIG. 4 is a diagram showing a cross-sectional configuration of a portion of a gas sensor according to a second embodiment; FIG. 5 is a schematic plan view of a gas sensor device according to a third embodiment; FIG. 6 is an enlarged cross-sectional view of the vicinity of an inclined surface of a laminate according to a sixth embodiment;

[0009] First, embodiments of the present disclosure will be described. (1) A gas sensor according to the present disclosure includes a laminate in which electrode layers and insulating layers are alternately stacked, and the laminate has an inclined surface on at least a part of its side surface, and the inclined surface functions as a detection portion for detecting a specific component of a gas to be measured.

[0010] (2) In the gas sensor described in (1), the laminate may have a specific electrode layer in at least one of the top and bottom layers, which is continuous with the inclined surface and has a horizontal surface extending perpendicular to the stacking direction, and a sensitive film may be in contact with the side of the laminate over the entire stacking direction, and the sensitive film may be in contact from the horizontal surface to the portion of the inclined surface that is continuous with the horizontal surface.

[0011] (3) In the gas sensor described in (2), the uppermost and lowermost layers of the laminate may both be the specific electrode layers having the horizontal surface, and the sensitive film may be in contact with the horizontal surface of both the uppermost and lowermost layers to a portion of the inclined surface that is continuous with the horizontal surface.

[0012] (4) In the gas sensor according to (2) or (3), the specific electrode layer may be inclined from a horizontal surface of the specific electrode layer and may form a part of the inclined surface.

[0013] (5) In the gas sensor according to any one of (2) to (4), the surface of the laminate preferably has a horizontal surface extending perpendicular to the stacking direction and an inclined surface continuing from the horizontal surface and inclined with respect to the stacking direction, and the angle of the inclined surface of the electrode layer is preferably larger than that of the insulating layer. This makes it easier to arrange the sensitive film on the insulating layer.

[0014] (6) In the gas sensor according to any one of (1) to (5), the surface of the laminate preferably has a horizontal surface extending perpendicular to the stacking direction and an inclined surface continuing from the horizontal surface and inclined with respect to the stacking direction, and the angle of the inclined surface of the insulating layer is preferably larger than that of the electrode layer. In this way, the gap can be shortened while maintaining a constant distance between the electrodes.

[0015] (7) In the gas sensor according to any one of (1) to (6), a heater capable of heating the laminate is preferably provided inside the insulating layer, and the heater is preferably positioned so as not to overlap the inclined surface when viewed from the stacking direction, thereby preventing cracks from occurring in the sensitive film due to the edge of the heater.

[0016] <Embodiment 1> Embodiment 1 of the present disclosure will be described with reference to FIG. 1 and other figures. In this embodiment, a gas sensor 100 capable of detecting a specific gas (measurement gas) is illustrated. In FIGS. 2 and 3, the Z direction is the stacking direction, and the X direction perpendicular to the Z direction is the horizontal direction. The front side of the page in FIG. 1 and the upper side of the page in FIGS. 2 and 3 are the front side (upper side in the stacking direction) of the gas sensor 100, and the back side of the page in FIG. 1 and the lower side of the page in FIGS. 2 and 3 are the back side (lower side in the stacking direction) of the gas sensor 100.

[0017] 1 , the gas sensor 100 includes a flat substrate 10, a laminate 11 laminated on the surface of the substrate 10, and a first wiring 15 and a second wiring 16 disposed on the surface of the substrate 10 and connected to the laminate 11. The substrate 10 is made of, for example, silicon. The gas sensor 100, together with a power source 2 and an ammeter 3, constitutes a gas sensor device 1. The power source 2 is connected to the first wiring 15 and the ammeter 3. The ammeter 3 is connected to the second wiring 16.

[0018] As shown in FIG. 2 , the laminate 11 includes multiple electrode layers 31 and 32 and multiple insulating layers 21, 22, 23, 24, and 25 stacked in the stacking direction (vertical direction). Specifically, the first insulating layer 21, the second insulating layer 22, and the third insulating layer 23 are stacked in this order on the surface of the substrate 10. The first electrode layer 31, the fourth insulating layer 24, the second electrode layer 32, and the fifth insulating layer 25 are stacked in this order on the surface of the third insulating layer 23. For the layers from the third insulating layer 23 to the fifth insulating layer 25, the multiple insulating layers 23, 24, and 25 and the multiple electrode layers 31 and 32 are stacked alternately in the stacking direction. As shown in FIG. 3 , the first electrode layer 31, the fourth insulating layer 24, the second electrode layer 32, and the fifth insulating layer 25 are referred to as the main layer portion 12.

[0019] In the stacking direction, the distance between the first electrode layer 31 and the second electrode layer 32 (the thickness of the fourth insulating layer 24) is on the order of nanometers, and may be, for example, 1 nm or more and less than 1000 nm, less than 100 nm, or several tens of nm. The first electrode layer 31 is connected to the first wiring 15 shown in FIG. 1 . The second electrode layer 32 is connected to the second wiring 16.

[0020] The material of each electrode layer 31, 32 and each wiring 15, 16 is not particularly limited, but may be any material having conductivity, for example, one or more of metals such as aluminum, copper, gold, platinum, etc. The material of each insulating layer 21, 22, 23, 24, 25 is not particularly limited, but may be any material having no conductivity, for example, SiO ２ and Si ３ N ４The second insulating layer 22 is provided with a heater 50 therein that can heat the laminate 11 .

[0021] As shown in Figure 2, the surface 11A of the laminate 11 includes a first horizontal surface 11B, which is a surface extending perpendicular (horizontally) to the stacking direction, a second horizontal surface 11D, which is a surface extending perpendicular to the stacking direction and is arranged above the first horizontal surface 11B, and an inclined surface 11C, which is a surface that is connected to the first horizontal surface 11B and the second horizontal surface 11D and is inclined with respect to the stacking direction.

[0022] The first electrode layer 31 includes a thin layer portion 36, a thick layer portion 38 that is thicker than the thin layer portion 36, and a gradually varying layer portion 37 that is disposed between the thin layer portion 36 and the thick layer portion 38 and whose thickness gradually varies in the horizontal direction. The thick layer portion 38 is thicker than the second electrode layer 32. As shown in FIG. 3 , a fourth insulating layer 24 is laminated on a surface (upper surface) 38A of the thick layer portion 38.

[0023] The first horizontal surface 11B is the surface (top surface) of the thin layer portion 36. The inclined surface 11C is the side surface of the first electrode layer 31, and is a surface formed by connecting the side surface 37A of the gradually changing layer portion 37, the side surface 24A of the fourth insulating layer 24, the side surface 32A of the second electrode layer 32, and the side surface 25A of the fifth insulating layer 25. The inclined surface 11C is the side surface of the main layer portion 12 in the laminate 11. The second horizontal surface 11D is the surface (top surface) of the fifth insulating layer 25. The inclined surface 11C functions as a detection unit capable of detecting a specific gas (a specific component of a measurement gas such as air).

[0024] The first electrode layer 31 is the lowest layer in the main layer portion 12 and is a specific electrode layer having a first horizontal surface 11B continuous with the inclined surface 11C. The first electrode layer 31 as a specific electrode layer has a side surface 37A of the gradually changing layer portion 37 that rises at an angle from the first horizontal surface 11B of the first electrode layer 31 and forms part of the inclined surface 11C. The angle θ of a corner 39 formed by the first horizontal surface 11B and the inclined surface 11C (or the side surface 37A) is an obtuse angle greater than 90 degrees, and specifically, is preferably 120 degrees or more and 150 degrees or less, and particularly preferably 130 degrees or more and 140 degrees or less.

[0025] The gas sensor 100 includes a sensitive film 40 that contacts the entire side surface (inclined surface 11C) of the laminate 11 in the stacking direction (the entire surface of inclined surface 11C). The sensitive film 40 also contacts from the first horizontal surface 11B to the side surface 37A of the gradually changing layer portion 37 (the portion of inclined surface 11C that continues to the first horizontal surface 11B). The sensitive film 40 also contacts the corner portion 39. The sensitive film 40 also contacts from the inclined surface 11C to the second horizontal surface 11D.

[0026] The sensitive film 40 is configured such that its own electrical characteristics (for example, resistance value) change in response to a specific gas. The material of the sensitive film 40 may be appropriately selected depending on the gas to be detected, and is not particularly limited. For example, an oxide semiconductor film can be used. Examples of oxide semiconductor films include ZnO, SnO ２ , W.O. ３ , In ２ O ３ , TiO ２ , and V ２ O ５ In the gas sensor 100, when a specific gas reacts with the sensitive film 40 and the resistance value of the sensitive film 40 changes, the current value of the ammeter 3 connected to the power source 2 in the gas sensor device 1 changes. This enables the gas sensor device 1 to detect the specific gas.

[0027] The manufacturing method of the gas sensor 100 is not particularly limited. For example, in the process of forming the laminate 11, ion etching may be performed from the surface side of the fifth insulating layer 25 to form the inclined surface 11C and the first horizontal surface 11B.

[0028] Next, the effects of this embodiment will be described. The gas sensor 100 of this embodiment includes a laminate 11 in which electrode layers 31, 32 and insulating layers 24 are alternately stacked, and the laminate 11 has an inclined surface 11C on at least a part of its side surface, and the inclined surface 11C functions as a detection portion for detecting a specific component of a measurement gas.

[0029] With this configuration, it is possible to increase the area of ​​the region in which specific components of the measured gas can be detected, thereby improving the detection sensitivity, compared to, for example, when the part that functions as the detection section on the side of the stack 11 extends in the vertical direction.

[0030] The laminate 11 has a specific electrode layer 31 in at least one of the top and bottom layers, which is connected to the inclined surface 11C and has a horizontal surface 11B extending perpendicular to the stacking direction, and a sensitive film 40 is in contact with the side of the laminate 11 throughout the entire stacking direction, and the sensitive film 40 is in contact from the horizontal surface 11B to the portion of the inclined surface 11C that is connected to the horizontal surface 11B.

[0031] With this configuration, the gas sensor 100 includes the sensitive film 40 that contacts the side surface of the laminate 11, which is made up of alternately stacked electrode layers 31, 32 and insulating layers 24, over the entire stacking direction, so that the measured gas reacts with the sensitive film 40, causing a change in the electrical properties (e.g., resistance value) of the sensitive film 40, thereby enabling the gas sensor 100 to detect the measured gas with high sensitivity and selectivity through the electrode layers 31, 32. Furthermore, the laminate 11 includes the specific electrode layer 31 having the inclined surface 11C disposed on at least a part of its side surface and the horizontal surface 11B, and the sensitive film 40 contacts the inclined surface 11C from the horizontal surface 11B to the portion of the inclined surface 11C that is continuous with the horizontal surface 11B. This increases the contact area with the sensitive film 40 and provides an anchor effect, thereby improving the detection sensitivity of the gas sensor 100, compared to a case where the side surface of the laminate 11 extends in the vertical direction. Here, when the horizontal surface and the side surface of the laminate are perpendicular to each other and the sensitive membrane is in contact with them, or when multiple electrode layers are arranged on the surface of the insulating layer and the sensitive membrane is in contact with them, the sensitive membrane is bent (for example, at a right angle) to follow the shape of the electrode layers, etc., and there is a risk of cracks or breaks occurring at the bent portion (this is called a step break). However, in the gas sensor 100 described above, the sensitive membrane 40 is in contact from the horizontal surface 11B to the portion of the inclined surface 11C that is continuous with the horizontal surface 11B, so that the sensitive membrane 40 is prevented from being bent at least at a right angle. This makes it possible to achieve a configuration that increases the contact area between each layer and the sensitive membrane 40 while suppressing step breaks.

[0032] The specific electrode layer 31 rises at an incline from its own horizontal surface 11B and forms part of an inclined surface 11C.

[0033] In the gas sensor 100, the specific electrode layer 31 rises at an angle from its own horizontal surface 11B and forms part of the inclined surface 11C, and the sensitive film 40 is in contact with the horizontal surface 11B and the portion of the inclined surface 11C that is continuous with the horizontal surface 11B, thereby further increasing the contact area with the sensitive film 40 and improving detection sensitivity. Furthermore, since the sensitive film 40 is in contact with the horizontal surface 11B and the inclined surface of one electrode layer 31 (specific electrode layer 31), a structure in which the sensitive film 40 is in sufficient contact with the electrode layer 31 can be achieved.

[0034] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to Fig. 4. In this embodiment, the same components as those in the above embodiment are designated by the same reference numerals, and redundant descriptions of the structure, operation, and effects will be omitted.

[0035] In the gas sensor 200, the laminate 211 includes a plurality of electrode layers 231, 232R, and 232L and a plurality of insulating layers 21, 22, 23, 224R, 224L, and 225 stacked in a stacking direction (vertical direction). A first electrode layer 231, fourth insulating layers 224R and 224L, second electrode layers 232R and 232L, and a fifth insulating layer 225 are stacked in this order on the surface of the third insulating layer 23. For the layers from the third insulating layer 23 to the fifth insulating layer 225, the plurality of insulating layers 23, 224R, 224L, and 225 and the plurality of electrode layers 231, 232R, and 232L are stacked alternately in the stacking direction. The second electrode layers 232R and 232L and the fourth insulating layers 224R and 224L include those arranged on the right side of the paper with respect to a first horizontal surface 211B (described later) (the second electrode layer 232R and the fourth insulating layer 224R), and those arranged on the left side of the paper with respect to the first horizontal surface 211B (the second electrode layer 232L and the fourth insulating layer 224L). The first electrode layer 231, the fourth insulating layer 224R on the right side, and the second electrode layer 232R on the right side are referred to as a main layer portion 212.

[0036] The surface 211A of the laminate 211 comprises a first horizontal surface 211B which is a surface extending horizontally, a second horizontal surface 211D which is also a surface extending horizontally and is arranged above the first horizontal surface 211B, and a first inclined surface (inclined surface) 211C which is connected to the first horizontal surface 211B and the second horizontal surface 211D and is a surface inclined with respect to the stacking direction. Furthermore, surface 211A is a horizontally extending surface and includes a third horizontal surface 211F arranged above first horizontal surface 211B and below second horizontal surface 211D, a second inclined surface 211E connected to first horizontal surface 211B and third horizontal surface 211F and inclined with respect to the stacking direction, a fourth horizontal surface 211H arranged above second horizontal surface 211D, and an end surface 211G connected to third horizontal surface 211F and fourth horizontal surface 211H and along the stacking direction.

[0037] The first electrode layer 231 includes a thin layer portion 236, thick layer portions 238R, 238L that are thicker than the thin layer portion 236, and gradually changing layer portions 237R, 237L that are arranged between the thin layer portion 236 and the thick layer portions 238R, 238L and that have a gradually changing thickness in the horizontal direction. The thick layer portions 238R, 238L are thicker than the second electrode layers 232R and 232L. The gradually changing layer portions 237R, 237L and the thick layer portions 238R, 238L include those (237R, 238R) that are arranged on the right side of the thin layer portion 236 in the plane of the drawing and those (237L, 238L) that are arranged on the left side of the thin layer portion 236 in the plane of the drawing.

[0038] The first horizontal surface 211B is the surface of the thin layer portion 236. The first inclined surface 211C is part of the side surfaces (first inclined surface 211C, second inclined surface 211E, and end surface 211G) of the laminate 211 and is the side surface of the main layer portion 212. The first inclined surface 211C is a surface where the side surface of the right gradually-changing layer portion 237R, the side surface of the right fourth insulating layer 224R, and the side surface of the right second electrode layer 232R are joined. The second inclined surface 211E is a surface where the side surface of the left gradually-changing layer portion 237L and the side surface of the left fourth insulating layer 224L are joined. The third horizontal surface 211F is the surface (top surface) of the left fourth insulating layer 224L. The end surface 211G is a surface where the end surface of the left second electrode layer 232L and the end surface of the fifth insulating layer 225 are joined together. The fourth horizontal surface 211H is the surface (upper surface) of the fifth insulating layer 225.

[0039] Of the laminate 211, the bottom layer (first electrode layer 231) and the top layer (second electrode layer 232R on the right side) in the main body layer portion 212 are both specific electrode layers having horizontal surfaces 211B, 211D. The first electrode layer 231 is the bottom layer in the main body layer portion 212 and is considered to be the first specific electrode layer having the first horizontal surface 211B continuing to the inclined surface 211C. The second electrode layer 232R on the right side is the top layer in the main body layer portion 212 and is considered to be the second specific electrode layer having the second horizontal surface 211D continuing to the inclined surface 211C. The sensitive film 240 contacts the horizontal surfaces 211B, 211D of both the bottom layer (first electrode layer 231) and the top layer (right-side second electrode layer 232R) with the portions of the inclined surface 211C that are continuous with the horizontal surfaces 211B, 211D (inclined end portions 211C1, 211C2). With this configuration, the contact area between the stack 211 and the sensitive film 240 can be increased, thereby improving detection sensitivity.

[0040] The sensitive film 240 is in contact with the entire surface 211A of the laminate 211. Specifically, the sensitive film 240 is in contact with the first horizontal surface 211B, the first inclined surface 211C, the second horizontal surface 211D, the second inclined surface 211E, the third horizontal surface 211F, the end surface 211G, and the fourth horizontal surface 211H.

[0041] Third Embodiment Next, a third embodiment of the present disclosure will be described with reference to Figures 5 and 6. In this embodiment, the same components as those in the above-described embodiment are designated by the same reference numerals, and redundant descriptions of the structure, operation, and effects will be omitted.

[0042] 5, the gas sensor 300 includes a first wiring 315 and a second wiring 316 connected to a laminate 311. The first wiring 315 branches into a rear wiring 315A and a front wiring 315B. Similarly, the second wiring 316 branches into a rear wiring 316A and a front wiring 316B. The gas sensor 300, together with a power source 2 and an ammeter 3, constitutes a gas sensor device 301.

[0043] As shown in Fig. 6, the laminate 311 includes multiple electrode layers 31, 32, 333, and 334 and multiple insulating layers 21, 22, 23, 24, 25, 326, and 327 stacked in the stacking direction (vertical direction). A third electrode layer 333, a sixth insulating layer 326, a fourth electrode layer 334, and a seventh insulating layer 327 are stacked in this order on the surface of the fifth insulating layer 25. The first electrode layer 31 is connected to the rear wiring 315A of the first wiring 315 shown in Fig. 1. The second electrode layer 32 is connected to the rear wiring 316A of the second wiring 316. The third electrode layer 333 is connected to the front wiring 315B of the first wiring 315. The fourth electrode layer 334 is connected to the front wiring 316B of the second wiring 316.

[0044] On the surface 311A ​​of the laminate 311, the first horizontal surface 311B is the surface (top surface) of the thin layer portion 36. The inclined surface 311C is a surface formed by connecting the side surface of the gradually changing layer portion 37, the side surface of the fourth insulating layer 24, the side surface of the second electrode layer 32, the side surface of the fifth insulating layer 25, the side surface of the third electrode layer 333, the side surface of the sixth insulating layer 326, the side surface of the fourth electrode layer 334, and the side surface of the seventh insulating layer 327. The second horizontal surface 311D is the surface (top surface) of the seventh insulating layer 327. The sensitive film 340 contacts the first horizontal surface 311B and the inclined surface 311C, and further contacts the inclined surface 311C and the second horizontal surface 311D.

[0045] Fourth Embodiment Next, a fourth embodiment of the present disclosure will be described with reference to Fig. 7. In this embodiment, the arrangement of the heater 50 in the first embodiment is changed, and the same reference numerals are used for the same parts as in the first embodiment, and redundant explanations of the structure, operation, and effects will be omitted.

[0046] 7 , the laminate 11 of the gas sensor 400 is formed by stacking a plurality of electrode layers 31 and 32 and a plurality of insulating layers 21, 22, 23, 24, and 25 in a stacking direction (vertical direction). A heater 50 capable of heating the laminate 11 is provided inside the second insulating layer 22.

[0047] The surface 11A of the laminate 11 includes a first horizontal surface 11B that extends perpendicularly (horizontally) to the stacking direction, a second horizontal surface 11D that also extends perpendicularly to the stacking direction and is disposed above the first horizontal surface 11B, and an inclined surface 11C that connects the first horizontal surface 11B and the second horizontal surface 11D and is inclined with respect to the stacking direction. When viewed from the stacking direction, the heater 50 is disposed so as not to overlap the inclined surface 11C but to overlap the first horizontal surface 11B. If the heater were disposed so as to overlap the inclined surface, there is a risk that the sensitive film 40 would crack and malfunction. Therefore, in this embodiment, the heater 50 is disposed so as not to overlap the inclined surface 11C.

[0048] Fifth Embodiment Next, a fifth embodiment of the present disclosure will be described with reference to Fig. 8. In this embodiment, the shape of the inclined surface 11C of the first embodiment is changed, and the same reference numerals are used for the same parts as those of the first embodiment, and redundant descriptions of the structure, operation, and effects will be omitted.

[0049] 8 , the laminate 511 of the gas sensor 500 is formed by stacking a plurality of electrode layers 531 and 532 and a plurality of insulating layers 523, 524, and 525 in a stacking direction (vertical direction). The first electrode layer 531, the fourth insulating layer 524, the second electrode layer 532, and the fifth insulating layer 525 form a main layer portion 512.

[0050] The surface 511A of the laminate 511 comprises a first horizontal surface 511B which is a surface extending perpendicular (horizontally) to the stacking direction, a second horizontal surface 511D which is a surface extending perpendicular to the stacking direction and is arranged above the first horizontal surface 511B, and an inclined surface 511C which is connected to the first horizontal surface 511B and the second horizontal surface 511D and is a surface inclined with respect to the stacking direction.

[0051] The inclined surface 511C is a side surface of the first electrode layer 531, and is a surface formed by joining a side surface 537A of the gradually changing layer portion 537, a side surface 524A of the fourth insulating layer 524, a side surface 532A of the second electrode layer 532, and a side surface 525A of the fifth insulating layer 525. The inclined surface 511C is a side surface of the main body layer portion 512 in the laminate 511.

[0052] An upper surface 538A of the first electrode layer 531 is parallel to the first horizontal plane 511B. The angle of the side surface 524A of the fourth insulating layer 524 that forms an acute angle with the first horizontal plane 511B is equal to the angle θ1 of the side surface 524A of the fourth insulating layer 524 that forms an acute angle with the upper surface 538A of the first electrode layer 531. The angle θ1 is the angle of the inclined surface 511C of the fourth insulating layer 524.

[0053] The top surface of the fourth insulating layer 524 is parallel to the first horizontal plane 511B. The angle of the side surface 532A of the second electrode layer 532 that forms an acute angle with the first horizontal plane 511B is equal to the angle θ2 of the side surface 532A of the second electrode layer 532 that forms an acute angle with the top surface of the fourth insulating layer 524. The angle θ2 is the angle of the inclined surface 511C of the second electrode layer 532.

[0054] In this embodiment, the angle θ 1 is greater than the angle θ 2 , which makes it easier to arrange the sensitive film 540 on the side surface 532 A of the second electrode layer 532 .

[0055] Sixth Embodiment Next, a sixth embodiment of the present disclosure will be described with reference to Fig. 9. In this embodiment, the shape of the inclined surface 511C of the fifth embodiment is changed, and the same reference numerals are used for the same parts as in the fifth embodiment, and redundant explanations of the structure, operation, and effects will be omitted. For configurations corresponding to the fifth embodiment, the numerals are used in which the digit in the hundreds digit of the numeral portion is changed from 5 to 6.

[0056] In this embodiment, the angle θ2 is greater than the angle θ1, so the gap between the first electrode layer 631 and the second electrode layer 632 can be shortened while maintaining a constant distance therebetween.

[0057] Next, a seventh embodiment of the present disclosure will be described with reference to Fig. 10. In this embodiment, a deviation occurs in the inclined surface 11C of the first embodiment, and the same reference numerals are used for the same parts as in the first embodiment, and redundant explanations of the structure, operation, and effects will be omitted. For configurations corresponding to the first embodiment, reference numerals with 7 added to the hundreds digit of the numeral portion are used.

[0058] In this embodiment, a side surface 724 A of the fourth insulating layer 724 and a side surface 725 A of the fifth insulating layer 725 protrude beyond the side surface 37 A of the gradually changing layer portion 37 and the side surface 32 A of the second electrode layer 32 .

[0059] Next, an eighth embodiment of the present disclosure will be described with reference to Fig. 11. In this embodiment, a deviation occurs in the inclined surface 11C of the first embodiment, and the same reference numerals are used for the same parts as in the first embodiment, and redundant explanations of the structure, operation, and effects will be omitted. For configurations corresponding to the first embodiment, reference numerals with 8 added to the hundreds digit of the numeral portion are used.

[0060] In this embodiment, a side surface 824 A of the fourth insulating layer 824 and a side surface 825 A of the fifth insulating layer 825 are recessed relative to a side surface 37 A of the gradually changing layer portion 37 and a side surface 32 A of the second electrode layer 32 .

[0061] <Other Embodiments> The present disclosure is not limited to the embodiments described above and in the drawings. For example, the following embodiments are also included within the technical scope of the present disclosure. Furthermore, various modifications other than those described below can be made without departing from the spirit of the present disclosure.

[0062] (1) In addition to the above-described embodiments, the configuration of the laminate can be modified as appropriate. The laminate may be configured to include at least a first electrode layer, an insulating layer laminated on the first electrode layer, and a second electrode layer laminated on the insulating layer. In such a configuration, the top surface of the second electrode layer may be in contact with the sensitive membrane.

[0063] (2) In addition to the above-described embodiment, the configuration of the sensitive film can be modified as appropriate. The sensitive film may be in contact with the first horizontal surface and the inclined surface, but not the second horizontal surface. Alternatively, the sensitive film may be in contact with a portion of the first horizontal surface and an inclined surface that is continuous with the portion of the first horizontal surface.

[0064] (3) The wiring configuration can be changed as appropriate. In the above embodiment, the wiring is arranged so as to connect to both sides of the stack (both the left and right sides of the paper in FIG. 1 ), but this is not limited thereto. For example, the wiring may be arranged so as to connect to the front side of the stack (the lower side of the paper in FIG. 1 ).

[0065] (4) In the gas sensor device, the instrument for measuring electrical characteristics is not limited to an ammeter that measures current, but may be a measuring instrument that measures various electrical characteristics, such as a voltmeter or an ohmmeter.

[0066] 10...substrate, 11,211,311,511,611,711,811...laminated body, 11B,211B,311B,511B,611B,711B,811B...first horizontal surface (horizontal surface), 11C,211C,311C,511C,611C,711C,811C...inclined surface, 24,224R,524,624,724,824...fourth insulating layer (insulating layer), 31,32,231,232R,531,631...electrode layer, 40,240,340,440,540,640,740,840...sensitive film, 100,200,300,400,500,600,700,800...gas sensor

Claims

1. A gas sensor comprising a laminate in which electrode layers and insulating layers are alternately stacked, the laminate having an inclined surface on at least a portion of a side surface, the inclined surface functioning as a detection portion for detecting a specific component of a measured gas.

2. The gas sensor of claim 1, wherein the laminate comprises, in at least one of the top and bottom layers, a specific electrode layer having a horizontal surface that is connected to the inclined surface and extends perpendicular to the stacking direction, a sensitive film is in contact with the side of the laminate over the entire stacking direction, and the sensitive film is in contact with the horizontal surface over the portion of the inclined surface that is connected to the horizontal surface.

3. A gas sensor as described in claim 2, wherein the uppermost and lowermost layers of the laminate are both specific electrode layers having the horizontal surface, and the sensitive film is in contact with the horizontal surface of both the uppermost and lowermost layers and a portion of the inclined surface that is continuous with the horizontal surface.

4. The gas sensor according to claim 2 or 3, wherein the specific electrode layer rises at an incline from a horizontal surface of the specific electrode layer itself and constitutes a part of the inclined surface.

5. The gas sensor according to claim 2, wherein a surface of the laminate has a horizontal plane extending perpendicular to the lamination direction and an inclined plane connected to the horizontal plane and inclined with respect to the lamination direction, and the angle of the inclined plane is larger in the electrode layer than in the insulating layer.

6. The gas sensor according to claim 1, wherein a surface of the laminate has a horizontal plane extending perpendicular to the lamination direction and an inclined plane connected to the horizontal plane and inclined with respect to the lamination direction, and the angle of the inclined plane is larger in the insulating layer than in the electrode layer.

7. The gas sensor according to claim 1, wherein a heater capable of heating the laminate is provided inside the insulating layer, and the heater is positioned so as not to overlap the inclined surface when viewed from the stacking direction.

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