JP2022030596A - MEMS type semiconductor gas detection element - Google Patents

MEMS type semiconductor gas detection element Download PDF

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JP2022030596A
JP2022030596A JP2020134712A JP2020134712A JP2022030596A JP 2022030596 A JP2022030596 A JP 2022030596A JP 2020134712 A JP2020134712 A JP 2020134712A JP 2020134712 A JP2020134712 A JP 2020134712A JP 2022030596 A JP2022030596 A JP 2022030596A
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electrode
gas
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conductive film
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JP7421441B2 (en
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忠司 中谷
Tadashi Nakatani
祥一郎 中尾
Shoichiro Nakao
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New Cosmos Electric Co Ltd
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Abstract

To provide an MEMS type semiconductor gas detection element in which a gas sensing unit has excellent adhesion to an electrode.SOLUTION: An MEMS type semiconductor gas detection element 1 of the present invention includes: a substrate 2; an electrode 3 provided on the substrate 2; a heater 4 provided on the substrate 2; a gas sensing unit 5 electrically connected to the electrode 3 and provided on the substrate 2 so as to be thermally connected to the heater 4; and a conductive film 6 for connecting the electrode 3 and the gas sensing unit 5 to each other, the conductive film having higher adhesion with the gas sensing unit 5 than the electrode 3. The conductive film 6 is connected to at least a part of an upper surface of the electrode 3 so that a short-circuit is not generated in the electrode 3 in a route different from a route of the electrode 3.SELECTED DRAWING: Figure 1

Description

本発明は、ＭＥＭＳ型半導体式ガス検知素子に関する。 The present invention relates to a MEMS type semiconductor gas detection element.

従来、ガス検知器用のガス検知素子として、たとえば特許文献１に開示されるように、検知対象ガスを検知するためのガス感応部を備えたＭＥＭＳ型半導体式ガス検知素子が用いられている。特許文献１のＭＥＭＳ型半導体式ガス検知素子は、基板と、基板に設けられた電極およびヒータと、電極に電気的に接続され、ヒータに熱的に接続されたガス感応部とを備えている。 Conventionally, as a gas detection element for a gas detector, for example, as disclosed in Patent Document 1, a MEMS type semiconductor gas detection element provided with a gas sensitive unit for detecting a gas to be detected has been used. The MEMS type semiconductor gas detection element of Patent Document 1 includes a substrate, an electrode provided on the substrate, a heater, and a gas sensitive portion electrically connected to the electrode and thermally connected to the heater. ..

特開２０１６－７０７０４号公報Japanese Unexamined Patent Publication No. 2016-70704

このようなＭＥＭＳ型半導体式ガス検知素子では、ガス感応部は、特許文献１に開示されているように、基板上に設けられた電極に直接接触するように設けられる。ところが、電極に対するガス感応部の密着性が必ずしも十分でなく、ガス感応部と電極との間に良好な電気接続を確保することが難しい。ガス感応部と電極との間に良好な電気接続を確保することができないと、検知対象ガスがガス感応部に接触した際に生じるガス感応部の抵抗値の変化を正確に検知することができない。さらに、ガス感応部と電極との間の低い密着性は、ガス検知能力の経時的な変化をももたらし、たとえば高温高湿環境下に曝された場合に、経時的にガス検知感度が劣化するなどの問題が生じる。 In such a MEMS type semiconductor type gas detection element, the gas sensitive portion is provided so as to be in direct contact with an electrode provided on the substrate, as disclosed in Patent Document 1. However, the adhesion of the gas-sensitive portion to the electrode is not always sufficient, and it is difficult to secure a good electrical connection between the gas-sensitive portion and the electrode. Unless a good electrical connection can be secured between the gas-sensitive part and the electrode, it is not possible to accurately detect the change in the resistance value of the gas-sensitive part that occurs when the gas to be detected comes into contact with the gas-sensitive part. .. Furthermore, the low adhesion between the gas sensitive part and the electrode also causes a change in gas detection ability over time, and the gas detection sensitivity deteriorates over time, for example, when exposed to a high temperature and high humidity environment. Problems such as occur.

本発明は、上記問題に鑑みなされたもので、電極に対するガス感応部の密着性が優れたＭＥＭＳ型半導体式ガス検知素子を提供することを目的とする。 The present invention has been made in view of the above problems, and an object of the present invention is to provide a MEMS type semiconductor gas detection element having excellent adhesion of a gas sensitive portion to an electrode.

本発明のＭＥＭＳ型半導体式ガス検知素子は、基板と、前記基板に設けられる電極と、前記基板に設けられるヒータと、前記電極に電気的に接続し、前記ヒータに熱的に接続するように前記基板に設けられるガス感応部とを備えるＭＥＭＳ型半導体式ガス検知素子であって、前記電極と比較して前記ガス感応部に対する密着性が高く、前記電極と前記ガス感応部とを接続する導電膜を備え、前記導電膜は、前記電極の経路とは異なる経路で前記電極を電気的に短絡させないように、前記電極の少なくとも一部の上面に接続されることを特徴とする。 The MEMS type semiconductor gas detection element of the present invention is such that the substrate, the electrode provided on the substrate, the heater provided on the substrate, and the heater are electrically connected to the electrode and thermally connected to the heater. A MEMS type semiconductor gas detection element provided with a gas-sensitive portion provided on the substrate, which has higher adhesion to the gas-sensitive portion than the electrode and is conductive to connect the electrode and the gas-sensitive portion. It comprises a film and is characterized in that the conductive film is connected to the upper surface of at least a part of the electrode so as not to electrically short-circuit the electrode by a path different from that of the electrode.

また、前記導電膜は、前記ガス感応部に含まれる金属酸化物半導体の金属元素と同一の金属元素を含む金属酸化物半導体を主成分として形成されることが好ましい。 Further, it is preferable that the conductive film is formed mainly of a metal oxide semiconductor containing the same metal element as the metal element of the metal oxide semiconductor contained in the gas sensitive portion.

また、前記ＭＥＭＳ型半導体式ガス検知素子が、前記電極および前記導電膜よりも電気抵抗が大きい絶縁膜を備え、前記絶縁膜は、前記導電膜が前記電極の経路とは異なる（よりも短い）経路で前記電極を電気的に短絡させないように、前記電極の異なる２点間の隙間に形成されることが好ましい。 Further, the MEMS type semiconductor gas detection element includes the electrode and an insulating film having a larger electric resistance than the conductive film, and the conductive film has a conductive film different from (shorter than) the path of the electrode. It is preferably formed in the gap between two different points of the electrode so as not to electrically short-circuit the electrode in the path.

また、前記導電膜の少なくとも一部が、前記絶縁膜の上に設けられることが好ましい。 Further, it is preferable that at least a part of the conductive film is provided on the insulating film.

また、前記電極が、一方のリード線に接続される第１の端部を含む第１の端部領域と、他方のリード線に接続される第２の端部を含む第２の端部領域と、前記第１の端部領域と前記第２の端部領域との間に延び、前記第１の端部領域と前記第２の端部領域とを接続する本体領域とを備え、前記導電膜は、前記第１の端部領域および前記第２の端部領域に接続されることが好ましい。 Also, a first end region in which the electrode includes a first end connected to one lead wire and a second end region including a second end connected to the other lead wire. And a main body region extending between the first end region and the second end region and connecting the first end region and the second end region, the conductivity. The membrane is preferably connected to the first end region and the second end region.

また、前記電極は、前記ヒータを兼ねており、前記導電膜および前記絶縁膜は、前記ガス感応部よりも緻密であり、前記導電膜および前記絶縁膜は、前記ヒータを覆うように前記ヒータに接続されることが好ましい。 Further, the electrode also serves as the heater, the conductive film and the insulating film are denser than the gas-sensitive portion, and the conductive film and the insulating film cover the heater. It is preferable to be connected.

本発明によれば、電極に対するガス感応部の密着性が優れたＭＥＭＳ型半導体式ガス検知素子を提供することができる。 According to the present invention, it is possible to provide a MEMS type semiconductor gas detection element having excellent adhesion of a gas sensitive portion to an electrode.

本発明の第１実施形態のＭＥＭＳ型半導体式ガス検知素子の上面図である。It is a top view of the MEMS type semiconductor type gas detection element of 1st Embodiment of this invention. 図１のＩＩ－ＩＩ線断面図である。FIG. 2 is a sectional view taken along line II-II of FIG. 図２のＭＥＭＳ型半導体式ガス検知素子の変形例を示す断面図である。It is sectional drawing which shows the modification of the MEMS type semiconductor type gas detection element of FIG. 本発明の第２実施形態のＭＥＭＳ型半導体式ガス検知素子の上面図である。It is a top view of the MEMS type semiconductor type gas detection element of the 2nd Embodiment of this invention. 図４のＩＶ－ＩＶ線断面図である。FIG. 4 is a sectional view taken along line IV-IV of FIG. 図５のＭＥＭＳ型半導体式ガス検知素子の変形例を示す断面図である。It is sectional drawing which shows the modification of the MEMS type semiconductor type gas detection element of FIG. 実施例のＭＥＭＳ型半導体式ガス検知素子のガス濃度変化に対するセンサ出力変化を示すグラフであり、（ａ）は、実施例１のグラフであり、（ｂ）は、実施例３のグラフである。It is a graph which shows the sensor output change with respect to the gas concentration change of the MEMS type semiconductor type gas detection element of an Example, (a) is the graph of Example 1, and (b) is the graph of Example 3. 比較例のＭＥＭＳ型半導体式ガス検知素子のガス濃度変化に対するセンサ出力変化を示すグラフである。It is a graph which shows the sensor output change with respect to the gas concentration change of the MEMS type semiconductor type gas detection element of the comparative example. 実施例および比較例のＭＥＭＳ型半導体式ガス検知素子を２０℃、６０％ＲＨの標準環境で放置したときの経過日数と、ガス検知器が警報を発するメタン濃度との関係を示すグラフであり、（ａ）は、実施例３のグラフであり、（ｂ）は、比較例２のグラフである。It is a graph which shows the relationship between the elapsed days when the MEMS type semiconductor type gas detection element of an Example and a comparative example was left in the standard environment of 20 degreeC, 60% RH, and the methane concentration which a gas detector issues an alarm. (A) is a graph of Example 3, and (b) is a graph of Comparative Example 2. 実施例および比較例のＭＥＭＳ型半導体式ガス検知素子を４０℃、８５％ＲＨの高温高湿環境で放置したときの経過日数と、ガス検知器が警報を発するメタン濃度との関係を示すグラフであり、（ａ）は、実施例３のグラフであり、（ｂ）は、比較例２のグラフである。A graph showing the relationship between the number of days elapsed when the MEMS-type semiconductor gas detectors of Examples and Comparative Examples were left in a high-temperature and high-humidity environment at 40 ° C. and 85% RH, and the methane concentration at which the gas detector issues an alarm. Yes, (a) is a graph of Example 3, and (b) is a graph of Comparative Example 2. 実施例および比較例のサンプルの電極（ヒータ）への投入電力と、電極（ヒータ）が断線するまでの断線寿命との関係を示すグラフである。It is a graph which shows the relationship between the input power to the electrode (heater) of the sample of an Example and a comparative example, and the disconnection life until the electrode (heater) is disconnected.

以下、添付図面を参照して、本発明の２つの実施形態に係るＭＥＭＳ型半導体式ガス検知素子を説明する。ただし、以下に示す実施形態は例示に過ぎず、本発明のＭＥＭＳ型半導体式ガス検知素子は以下の例に限定されることはない。 Hereinafter, the MEMS type semiconductor gas detection element according to the two embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments shown below are merely examples, and the MEMS type semiconductor gas detection element of the present invention is not limited to the following examples.

＜第１実施形態＞
本実施形態のＭＥＭＳ型半導体式ガス検知素子は、たとえば大気などの環境雰囲気において、環境雰囲気に含まれる検知対象ガスを検知するために用いられる。ＭＥＭＳ型半導体式ガス検知素子は、表面に吸着した酸素と環境雰囲気中の検知対象ガスとの化学反応に伴って抵抗値（または電気伝導度）が変化することを利用して、検知対象ガスを検知する。検知対象ガスとしては、特に限定されることはなく、たとえば、メタン、ブタン、イソブタン、プロパン、一酸化炭素、水素、エタノールなどが例示される。 <First Embodiment>
The MEMS type semiconductor gas detection element of the present embodiment is used to detect a detection target gas contained in an environmental atmosphere in an environmental atmosphere such as the atmosphere. The MEMS type semiconductor gas detection element uses the fact that the resistance value (or electrical conductivity) changes with the chemical reaction between the oxygen adsorbed on the surface and the gas to be detected in the environmental atmosphere to detect the gas to be detected. Detect. The detection target gas is not particularly limited, and examples thereof include methane, butane, isobutane, propane, carbon monoxide, hydrogen, and ethanol.

ＭＥＭＳ型半導体式ガス検知素子１は、図１および図２に示されるように、ＭＥＭＳ（Ｍｉｃｒｏ Ｅｌｅｃｔｒｏ Ｍｅｃｈａｎｉｃａｌ Ｓｙｓｔｅｍ）構造を有している。ＭＥＭＳ構造とは、シリコン基板などの基板の上に微細加工技術によって素子構成要素の少なくとも一部を集積化したデバイス構造のことを意味する。ＭＥＭＳ型半導体式ガス検知素子１は、ＭＥＭＳ構造を有することにより、コイル型の半導体式ガス検知素子と比べて、小型化が可能で、低消費電力での駆動が可能である。 As shown in FIGS. 1 and 2, the MEMS type semiconductor gas detection element 1 has a MEMS (Micro Electro Electro Mechanical System) structure. The MEMS structure means a device structure in which at least a part of element components is integrated on a substrate such as a silicon substrate by microfabrication technology. Since the MEMS type semiconductor gas detection element 1 has a MEMS structure, it can be downsized and can be driven with low power consumption as compared with the coil type semiconductor gas detection element.

ＭＥＭＳ型半導体式ガス検知素子１は、図１および図２に示されるように、基板２と、基板２に設けられる電極３と、基板２に設けられるヒータ４と、電極３に電気的に接続し、ヒータ４に熱的に接続するように基板２に設けられるガス感応部５と、電極３とガス感応部５とを接続する導電膜６とを備える。ＭＥＭＳ型半導体式ガス検知素子１は、任意で、ガス感応部５を被覆する機能層７を備えていてもよい。なお、図１（図４も同様）においては、電極３およびヒータ４の配置を見やすくするために、ガス感応部５および機能層７の図示を省略するとともに、導電膜６を（図４では絶縁膜８も）２点鎖線で示している。 As shown in FIGS. 1 and 2, the MEMS type semiconductor gas detection element 1 is electrically connected to the substrate 2, the electrode 3 provided on the substrate 2, the heater 4 provided on the substrate 2, and the electrode 3. It also includes a gas-sensitive portion 5 provided on the substrate 2 so as to be thermally connected to the heater 4, and a conductive film 6 for connecting the electrode 3 and the gas-sensitive portion 5. The MEMS type semiconductor gas detection element 1 may optionally include a functional layer 7 that covers the gas sensitive portion 5. In addition, in FIG. 1 (the same applies to FIG. 4), in order to make the arrangement of the electrode 3 and the heater 4 easy to see, the gas sensitive portion 5 and the functional layer 7 are not shown, and the conductive film 6 is insulated (in FIG. 4). Membrane 8) is also shown by a two-dot chain line.

ＭＥＭＳ型半導体式ガス検知素子１は、たとえば、公知のブリッジ回路（図示せず）に組み込まれて、ガス感応部５の表面の吸着酸素と環境雰囲気中の検知対象ガスとの化学反応に伴う抵抗値の変化が検出される。ＭＥＭＳ型半導体式ガス検知素子１は、ガス感応部５の抵抗値の変化を検出するために、電極３を介してブリッジ回路に組み込まれる。ブリッジ回路は、ＭＥＭＳ型半導体式ガス検知素子１における抵抗値の変化によって生じる回路内の電位差の変化を電位差計によって測定して、その電位差の変化を検知対象ガスの検知信号として出力する。ただし、ＭＥＭＳ型半導体式ガス検知素子１は、ガス感応部５の表面の吸着酸素と検知対象ガスとの化学反応に伴って生じる抵抗値の変化を検出することができれば、ブリッジ回路に限定されることはなく、ブリッジ回路とは異なる回路に組み込まれて使用されてもよい。 The MEMS type semiconductor gas detection element 1 is incorporated into a known bridge circuit (not shown), for example, and has resistance due to a chemical reaction between the adsorbed oxygen on the surface of the gas sensitive portion 5 and the gas to be detected in the environmental atmosphere. A change in value is detected. The MEMS type semiconductor type gas detection element 1 is incorporated in a bridge circuit via an electrode 3 in order to detect a change in the resistance value of the gas sensitive unit 5. The bridge circuit measures the change in the potential difference in the circuit caused by the change in the resistance value in the MEMS type semiconductor gas detection element 1 with a potentiometer, and outputs the change in the potential difference as a detection signal of the detection target gas. However, the MEMS type semiconductor gas detection element 1 is limited to a bridge circuit as long as it can detect a change in resistance value caused by a chemical reaction between the adsorbed oxygen on the surface of the gas sensitive portion 5 and the gas to be detected. It may be used by being incorporated in a circuit different from the bridge circuit.

基板２は、基板２に対して電気的に絶縁状態となるように、電極３、ヒータ４、ガス感応部５、導電膜６を支持する部材であり、機能層７、第２実施形態における絶縁膜８、接着層９が設けられる場合はそれらも含んで支持する部材である。以下、電極３、ヒータ４、ガス感応部５、導電膜６（機能層７、第２実施形態における絶縁膜８、接着層９が設けられる場合はそれらも含む）をまとめて「集積部Ａ」ともいう。基板２は、基板２に対して電気的に絶縁状態で集積部Ａを支持することができればよく、その構成は特に限定されることはない。基板２は、本実施形態では、図１および図２に示されるように、基板本体２１と、基板本体２１に支持される絶縁支持膜２２と、基板本体２１と絶縁支持膜２２との間に設けられる空洞部２３とを備えている。 The substrate 2 is a member that supports the electrode 3, the heater 4, the gas sensitive portion 5, and the conductive film 6 so as to be electrically insulated from the substrate 2, and the functional layer 7 and the insulation in the second embodiment. When the film 8 and the adhesive layer 9 are provided, they are also included in the supporting member. Hereinafter, the electrode 3, the heater 4, the gas sensitive portion 5, and the conductive film 6 (including the functional layer 7, the insulating film 8 in the second embodiment, and the adhesive layer 9 if provided) are collectively referred to as the “integrated portion A”. Also called. The substrate 2 is not particularly limited as long as it can support the integrated portion A in an electrically insulated state with respect to the substrate 2. In the present embodiment, as shown in FIGS. 1 and 2, the substrate 2 is located between the substrate main body 21, the insulating support film 22 supported by the substrate main body 21, and the substrate main body 21 and the insulating support film 22. It is provided with a cavity 23 to be provided.

基板本体２１は、絶縁支持膜２２を支持し、絶縁支持膜２２を介して集積部Ａを支持する部材である。基板本体２１は、図２に示されるように、絶縁支持膜２２の下方（集積部Ａが設けられる側の反対側）に設けられ、下方から絶縁支持膜２２を支持する。基板本体２１は、絶縁支持膜２２との間に空洞部２３を形成するために、凹部２１ａが形成されている。ただし、基板本体２１は、絶縁支持膜２２との間に空洞部２３が設けられるように形成されていればよく、たとえば図３（図６の変形例も同様）の変形例に示されるように、凹部２１ａを有することなく、絶縁支持膜２２の端部を下方から支持しながら、絶縁支持膜２２の中央部分の下方には基板本体２１が全く存在しない構造を有していてもよい。基板本体２１は、絶縁支持膜２２を支持することができれば、特に限定されることはなく、たとえばシリコンなどにより形成される。 The substrate main body 21 is a member that supports the insulating support film 22 and supports the integrated portion A via the insulating support film 22. As shown in FIG. 2, the substrate main body 21 is provided below the insulating support film 22 (opposite the side where the integrated portion A is provided), and supports the insulating support film 22 from below. The substrate main body 21 is formed with a recess 21a in order to form a cavity 23 with the insulating support film 22. However, the substrate main body 21 may be formed so that the cavity 23 is provided between the substrate main body 21 and the insulating support film 22, as shown in, for example, a modification of FIG. 3 (the same applies to the modification of FIG. 6). It may have a structure in which the substrate main body 21 does not exist at all below the central portion of the insulating support film 22 while supporting the end portion of the insulating support film 22 from below without having the recess 21a. The substrate main body 21 is not particularly limited as long as it can support the insulating support film 22, and is formed of, for example, silicon.

絶縁支持膜２２は、集積部Ａと基板本体２１との間が電気的に絶縁状態となるように、集積部Ａを支持する部材である。絶縁支持膜２２は、図２に示されるように、基板本体２１に設けられて、基板本体２１により支持される。絶縁支持膜２２は、絶縁物により膜状に形成される。絶縁支持膜２２は、本実施形態では、基板本体２１に接続される酸化シリコン膜２２ａと、酸化シリコン膜２２ａ上に設けられる窒化シリコン膜２２ｂと、窒化シリコン膜２２ｂ上に設けられる酸化シリコン膜２２ｃとを備え、これらの３層が積層されて形成される。絶縁支持膜２２は、たとえばＣＶＤなどの公知の成膜技術により形成することができる。 The insulating support film 22 is a member that supports the integrated portion A so that the space between the integrated portion A and the substrate main body 21 is electrically insulated. As shown in FIG. 2, the insulating support film 22 is provided on the substrate main body 21 and is supported by the substrate main body 21. The insulating support film 22 is formed in the form of a film by an insulating material. In the present embodiment, the insulating support film 22 is a silicon oxide film 22a connected to the substrate main body 21, a silicon nitride film 22b provided on the silicon oxide film 22a, and a silicon oxide film 22c provided on the silicon nitride film 22b. These three layers are laminated and formed. The insulating support film 22 can be formed by a known film forming technique such as CVD.

絶縁支持膜２２は、基板本体２１との間を電気的に絶縁するように集積部Ａを支持することができればよく、その層構造、構成材料、膜厚は特に限定されない。たとえば、絶縁支持膜２２は、本実施形態では３層構造を有しているが、単層構造や３層以外の複層構造を有していてもよい。また、絶縁支持膜２２は、本実施形態では酸化シリコン膜や窒化シリコン膜により形成されているが、酸化アルミニウムなどの他の絶縁物により形成されてもよい。また、絶縁支持膜２２の膜厚は、特に限定されることはなく、基板本体２１との間を電気的に絶縁して集積部Ａを支持することができるように適宜設定することができる。 The insulating support film 22 may support the integrated portion A so as to electrically insulate the insulating support film 22 from the substrate main body 21, and its layer structure, constituent material, and film thickness are not particularly limited. For example, the insulating support film 22 has a three-layer structure in the present embodiment, but may have a single-layer structure or a multi-layer structure other than the three-layer structure. Further, although the insulating support film 22 is formed of a silicon oxide film or a silicon nitride film in the present embodiment, it may be formed of another insulating material such as aluminum oxide. Further, the film thickness of the insulating support film 22 is not particularly limited, and can be appropriately set so that the integrated portion A can be supported by electrically insulating the film from the substrate main body 21.

絶縁支持膜２２は、本実施形態では、図１および図２に示されるように、集積部Ａを支持する本体部２２１と、基板本体２１上に設けられる基部２２２と、本体部２２１と基部２２２とを接続する接続部２２３とを備えている。絶縁支持膜２２は、基部２２２を介して基板本体２１に支持され、本体部２２１を介して集積部Ａを支持する。本体部２２１、基部２２２および接続部２２３は、たとえば、基板本体２１上に均一な絶縁支持膜２２を形成した後に、公知のエッチング加工技術により形成することができる。 In the present embodiment, the insulating support film 22 has a main body portion 221 that supports the integrated portion A, a base portion 222 provided on the substrate main body 21, and a main body portion 221 and a base portion 222, as shown in FIGS. 1 and 2. It is provided with a connection unit 223 for connecting to and. The insulating support film 22 is supported by the substrate main body 21 via the base portion 222, and supports the integrated portion A via the main body portion 221. The main body portion 221 and the base portion 222 and the connection portion 223 can be formed by, for example, a known etching processing technique after forming a uniform insulating support film 22 on the substrate main body 21.

本体部２２１は、接続部２２３を介して基部２２２に接続され、接続部２２３および基部２２２を介して基板本体２１に支持される。本体部２２１は、基板本体２１との間に形成された空洞部２３を介して基板本体２１から離間して設けられる。ＭＥＭＳ型半導体式ガス検知素子１では、基板本体２１から離間して設けられる本体部２２１に集積部Ａが設けられることで、集積部Ａに加えられる熱が基板本体２１に伝導するのを抑制することができる。それによって、ＭＥＭＳ型半導体式ガス検知素子１では、集積部Ａをより効率よく加熱することができ、低消費電力の駆動が可能になる。本体部２２１は、本実施形態では、図１に示されるように、上面視で略円形状に形成されている。しかし、本体部２２１は、基板本体２１から離間して設けられ、集積部Ａを支持することができれば、特に限定されることはなく、上面視で略矩形状など他の形状に形成されてもよい。 The main body portion 221 is connected to the base portion 222 via the connecting portion 223, and is supported by the substrate main body 21 via the connecting portion 223 and the base portion 222. The main body portion 221 is provided apart from the substrate main body 21 via a cavity portion 23 formed between the main body portion 221 and the substrate main body 21. In the MEMS type semiconductor type gas detection element 1, the integrated portion A is provided in the main body portion 221 provided apart from the substrate main body 21, thereby suppressing the heat applied to the integrated portion A from being conducted to the substrate main body 21. be able to. As a result, in the MEMS type semiconductor type gas detection element 1, the integrated portion A can be heated more efficiently, and low power consumption can be driven. In the present embodiment, the main body portion 221 is formed in a substantially circular shape in a top view as shown in FIG. However, the main body portion 221 is not particularly limited as long as it is provided apart from the substrate main body 21 and can support the integrated portion A, and may be formed into another shape such as a substantially rectangular shape when viewed from above. good.

基部２２２は、図１および図２に示されるように、基板本体２１上に設けられ、基板本体２１に支持される。また、基部２２２は、接続部２２３を介して本体部２２１に接続され、接続部２２３を介して本体部２２１を支持する。基部２２２は、本実施形態では、中央部分が略矩形状にくり抜かれた枠状に形成され、その枠内に空洞部２３が形成されている。しかし、基部２２２は、基板本体２１上に設けられて、接続部２２３を介して本体部２２１を支持することができれば、特に限定されることはなく、略円形状など他の形状でくり抜かれた枠状に形成されてもよい。 The base 222 is provided on the substrate body 21 and supported by the substrate body 21, as shown in FIGS. 1 and 2. Further, the base portion 222 is connected to the main body portion 221 via the connecting portion 223, and supports the main body portion 221 via the connecting portion 223. In the present embodiment, the base portion 222 is formed in a frame shape in which the central portion is hollowed out in a substantially rectangular shape, and the cavity portion 23 is formed in the frame shape. However, the base portion 222 is not particularly limited as long as it is provided on the substrate main body 21 and the main body portion 221 can be supported via the connection portion 223, and is hollowed out in another shape such as a substantially circular shape. It may be formed in a frame shape.

接続部２２３は、図１に示されるように、本体部２２１と基部２２２とに接続されて、基部２２２に支持されながら本体部２２１を支持する。接続部２２３は、基板本体２１との間に形成された空洞部２３を介して基板本体２１から離間して設けられる。本体部２２１を基部２２２に接続する接続部２２３が基板本体２１から離間して設けられることにより、集積部Ａに加えられる熱が基板本体２１に伝導するのを抑制することができる。接続部２２３は、基部２２２の枠の内側面に接続され、基部２２２の枠の内側面から、基部２２２の枠の内側の略中央に位置する本体部２２１に向かって延びるように形成される。接続部２２３は、本実施形態では、基部２２２の枠の４つの内側面のそれぞれに接続され、隣り合う接続部２２３同士の間の角度が略等角度となる４方向から略等しい長さで本体部２２１を支持している。したがって、接続部２２３は、本体部２２１をバランスよく支持することができる。ただし、接続部２２３は、本体部２２１と基部２２２とを接続し、本体部２２１を支持することができればよく、図示された例に限定されることはない。 As shown in FIG. 1, the connecting portion 223 is connected to the main body portion 221 and the base portion 222, and supports the main body portion 221 while being supported by the base portion 222. The connecting portion 223 is provided apart from the substrate main body 21 via a hollow portion 23 formed between the connecting portion 223 and the substrate main body 21. By providing the connecting portion 223 for connecting the main body portion 221 to the base portion 222 at a distance from the substrate main body 21, it is possible to suppress the heat applied to the integrated portion A from being conducted to the substrate main body 21. The connecting portion 223 is connected to the inner side surface of the frame of the base portion 222, and is formed so as to extend from the inner side surface of the frame of the base portion 222 toward the main body portion 221 located substantially at the center inside the frame of the base portion 222. In the present embodiment, the connecting portion 223 is connected to each of the four inner side surfaces of the frame of the base 222, and the main body has substantially the same length from the four directions in which the angles between the adjacent connecting portions 223 are substantially equal. Supports part 221. Therefore, the connection portion 223 can support the main body portion 221 in a well-balanced manner. However, the connecting portion 223 is not limited to the illustrated example as long as it can connect the main body portion 221 and the base portion 222 and support the main body portion 221.

電極３は、ガス感応部５の抵抗値変化を検出するための部材である。電極３は、図１および図２に示されるように、基板２の絶縁支持膜２２の本体部２２１上に設けられ、その少なくとも一部がガス感応部５に電気的に接続される。電極３は、第１の端部３ａおよび第２の端部３ｂを備え、第１の端部３ａが一方のリード線Ｌ１に接続され、第２の端部３ｂが他方のリード線Ｌ２に接続される。リード線Ｌ１、Ｌ２は、電極３と比べて低い電気抵抗を有するように形成される。一方および他方のリード線Ｌ１、Ｌ２を、たとえば公知のブリッジ回路（図示せず）に接続して、電極３の第１の端部３ａと第２の端部３ｂとの間の抵抗値を測定することにより、電極３とガス感応部５との合成抵抗値を測定することができる。そして、電極３とガス感応部５との合成抵抗値の変化を測定することにより、ガス感応部５の抵抗値変化を検出することができる。 The electrode 3 is a member for detecting a change in the resistance value of the gas sensitive portion 5. As shown in FIGS. 1 and 2, the electrode 3 is provided on the main body portion 221 of the insulating support film 22 of the substrate 2, and at least a part thereof is electrically connected to the gas sensitive portion 5. The electrode 3 includes a first end 3a and a second end 3b, the first end 3a is connected to one lead L1 and the second end 3b is connected to the other lead L2. Will be done. The lead wires L1 and L2 are formed so as to have a lower electric resistance than the electrode 3. One and the other lead wires L1 and L2 are connected to, for example, a known bridge circuit (not shown), and the resistance value between the first end 3a and the second end 3b of the electrode 3 is measured. By doing so, the combined resistance value of the electrode 3 and the gas sensitive portion 5 can be measured. Then, by measuring the change in the combined resistance value between the electrode 3 and the gas-sensitive unit 5, it is possible to detect the change in the resistance value of the gas-sensitive unit 5.

電極３は、本実施形態では、通電により発熱して、ガス感応部５を（機能層７が設けられる場合は機能層７も）加熱するヒータ４としても機能する。つまり、本実施形態のＭＥＭＳ型半導体式ガス検知素子１では、電極３は、ヒータ４を兼ねており、逆に、ヒータ４は、電極３を兼ねている。したがって、電極３およびヒータ４は、ガス感応部５の抵抗値変化を検出することができるとともに、通電によって、ガス感応部５を、検知対象ガスの検知に適した温度に加熱することができる。ただし、電極３は、少なくともガス感応部５の抵抗値変化を検出することができればよく、ガス感応部５を加熱するためのヒータ４とは別に設けられてもよい。また、ヒータ４は、少なくともガス感応部５を加熱することができればよく、ガス感応部５の抵抗値変化を検出する電極３とは別に設けられてもよい。以下では、電極３の詳細を説明することで、ヒータ４の詳細な説明を省略する。電極３およびヒータ４がそれぞれ別に設けられる場合には、電極３およびヒータ４の両方を以下で説明する構成と同じ構成とすることもできるし、電極３およびヒータ４のいずれか一方を以下で説明する構成と同じ構成とし、電極３およびヒータ４の他方を以下で説明する構成と異なる構成とすることもできるし、電極３およびヒータ４の両方を以下で説明する構成と異なる構成とすることもできる。 In the present embodiment, the electrode 3 also functions as a heater 4 that generates heat by energization and heats the gas sensitive portion 5 (and the functional layer 7 if the functional layer 7 is provided). That is, in the MEMS type semiconductor gas detection element 1 of the present embodiment, the electrode 3 also serves as the heater 4, and conversely, the heater 4 also serves as the electrode 3. Therefore, the electrode 3 and the heater 4 can detect the change in the resistance value of the gas-sensitive unit 5, and can heat the gas-sensitive unit 5 to a temperature suitable for detecting the gas to be detected by energization. However, the electrode 3 may be provided separately from the heater 4 for heating the gas-sensitive portion 5, as long as it can detect at least the change in the resistance value of the gas-sensitive portion 5. Further, the heater 4 may be provided separately from the electrode 3 for detecting the change in the resistance value of the gas sensitive portion 5 as long as it can heat at least the gas sensitive portion 5. In the following, the details of the electrode 3 will be described, and the detailed description of the heater 4 will be omitted. When the electrode 3 and the heater 4 are provided separately, both the electrode 3 and the heater 4 may have the same configuration as described below, or one of the electrode 3 and the heater 4 may be described below. The other of the electrode 3 and the heater 4 may be configured differently from the configuration described below, or both the electrode 3 and the heater 4 may be configured differently from the configuration described below. can.

電極３は、ガス感応部５の抵抗値変化を検出することができればよく、その構成材料は特に限定されない。電極３は、たとえば白金、白金－ロジウム合金などの貴金属などにより形成することができる。電極３は、たとえば、電極３用材料により均一な膜を形成した後に、公知のエッチング加工技術により形成することができる。なお、電極３は、たとえば図２に示されるように、任意で、基板２の絶縁支持膜２２の本体部２２１との密着性を高めるために、また、図５に示されるように、第２実施形態のＭＥＭＳ型半導体式ガス検知素子１００に関連して後述する絶縁膜８との密着性を高めるために、酸化タンタルなどにより形成される接着層９を介して本体部２２１および絶縁膜８に接続されてもよい。 The electrode 3 is not particularly limited as long as it can detect a change in the resistance value of the gas sensitive portion 5. The electrode 3 can be formed of, for example, a precious metal such as platinum or a platinum-rhodium alloy. The electrode 3 can be formed by, for example, a known etching processing technique after forming a uniform film with the material for the electrode 3. It should be noted that the electrode 3 is optionally used as shown in FIG. 2, for the purpose of enhancing the adhesion of the insulating support film 22 of the substrate 2 to the main body 221 and as shown in FIG. In order to improve the adhesion to the insulating film 8 described later in relation to the MEMS type semiconductor gas detection element 100 of the embodiment, the main body portion 221 and the insulating film 8 are provided with an adhesive layer 9 formed of tantalum oxide or the like. It may be connected.

電極３は、ガス感応部５の抵抗値変化を検出することができるように配置されていればよく、その配線経路は特に限定されない。電極３は、本実施形態では、図１に示されるように、一方のリード線Ｌ１に接続される第１の端部３ａを含む第１の端部領域３１と、他方のリード線Ｌ２に接続される第２の端部３ｂを含む第２の端部領域３２と、第１の端部領域３１と第２の端部領域３２との間に延び、第１の端部領域３１と第２の端部領域３２とを接続する本体領域３３とを備えている。電極３は、第１の端部領域３１、第２の端部領域３２および本体領域３３を備え、単一の電極として構成される。ただし、電極は、ガス感応部の抵抗値変化を検出することができれば、本実施形態に限定されることはなく、互いに分離した２つ以上の電極により構成されてもよい。 The electrode 3 may be arranged so as to be able to detect a change in the resistance value of the gas sensitive portion 5, and its wiring path is not particularly limited. In this embodiment, the electrode 3 is connected to a first end region 31 including a first end 3a connected to one lead L1 and to the other lead L2, as shown in FIG. A second end region 32 including a second end region 3b to be formed, extending between the first end region 31 and the second end region 32, and a first end region 31 and a second. It is provided with a main body region 33 for connecting to the end region 32 of the above. The electrode 3 includes a first end region 31, a second end region 32, and a body region 33, and is configured as a single electrode. However, the electrode is not limited to this embodiment as long as the change in the resistance value of the gas-sensitive portion can be detected, and may be composed of two or more electrodes separated from each other.

第１の端部領域３１は、第１の端部３ａを含む、第１の端部３ａに隣接する電極３の一部の領域である。第１の端部領域３１は、第１の端部３ａから所定の長さの範囲の電極３の一部により構成される。本実施形態では、第１の端部領域３１は、図１に示されるように、基板２（本体部２２１）の端部近傍に配置された第１の端部３ａと、第１の端部３ａから基板２の中心に向かって延び、基板２の中心に最も近づいた部位である第１の近接部３ｃとの間の領域である。第１の端部領域３１は、本実施形態では、第１の端部３ａから基板２の中心に向かって略直線的に略最短距離で延びている。ただし、第１の端部領域３１は、第１の端部３ａから、少なくとも基板２の中心から遠ざかることなく、基板２の中心に近づくように延びていれば、図示された例に限定されることはなく、湾曲して延びていてもよい。また、第１の端部領域３１は、基板２の中心近傍に第１の端部３ａが配置されて、第１の端部３ａから、基板２の中心から離れる方向に延びる電極３の一部により構成されてもよい。 The first end region 31 is a partial region of the electrode 3 adjacent to the first end 3a, including the first end 3a. The first end region 31 is composed of a part of the electrodes 3 in a predetermined length range from the first end 3a. In the present embodiment, as shown in FIG. 1, the first end region 31 includes a first end portion 3a arranged near the end portion of the substrate 2 (main body portion 221) and a first end portion. It is a region extending from 3a toward the center of the substrate 2 and between the first proximity portion 3c, which is the portion closest to the center of the substrate 2. In the present embodiment, the first end region 31 extends substantially linearly from the first end 3a toward the center of the substrate 2 at a substantially shortest distance. However, the first end region 31 is limited to the illustrated example as long as it extends from the first end 3a so as to approach the center of the substrate 2 without moving away from at least the center of the substrate 2. It does not have to be curved and may extend. Further, the first end region 31 is a part of the electrode 3 in which the first end 3a is arranged near the center of the substrate 2 and extends from the first end 3a in a direction away from the center of the substrate 2. May be configured by.

第２の端部領域３２は、第２の端部３ｂを含む、第２の端部３ｂに隣接する電極３の一部の領域である。第２の端部領域３２は、第２の端部３ｂから所定の長さの範囲の電極３の一部により構成される。第２の端部領域３２は、本実施形態では、図１に示されるように、基板２（本体部２２１）の端部近傍に配置された第２の端部３ｂと、第２の端部３ｂから基板２の中心に向かって延び、基板２の中心に最も近づいた部位である第２の近接部３ｄとの間の領域である。第２の端部領域３２は、本実施形態では、第２の端部３ｂから基板２の中心に向かって略直線的に略最短距離で延びている。ただし、第２の端部領域３２は、第２の端部３ｂから、少なくとも基板２の中心から遠ざかることなく、基板２の中心に近づくように延びていれば、本実施形態に限定されることはなく、湾曲して延びていてもよい。また、第２の端部領域３２は、本実施形態では第１の端部領域３１と略平行かつ略一直線上に延び、第１の端部領域３１と略同一の長さを有しているが、第１の端部領域３１に対して傾斜して設けられていてもよく、第１の端部領域３１とは異なる長さを有していてもよい。また、第２の端部領域３２は、基板２の中心近傍に第２の端部３ｂが配置されて、第２の端部３ｂから、基板２の中心から離れる方向に延びる電極３の一部により構成されてもよい。 The second end region 32 is a partial region of the electrode 3 adjacent to the second end 3b, including the second end 3b. The second end region 32 is composed of a part of the electrodes 3 in a predetermined length range from the second end 3b. In the present embodiment, the second end region 32 includes a second end portion 3b arranged near the end portion of the substrate 2 (main body portion 221) and a second end portion, as shown in FIG. It is a region extending from 3b toward the center of the substrate 2 and between the second proximity portion 3d, which is the portion closest to the center of the substrate 2. In the present embodiment, the second end region 32 extends substantially linearly from the second end 3b toward the center of the substrate 2 at a substantially shortest distance. However, the second end region 32 is limited to the present embodiment as long as it extends from the second end 3b so as to approach the center of the substrate 2 without moving away from at least the center of the substrate 2. It may be curved and extended. Further, in the present embodiment, the second end region 32 extends substantially parallel to and substantially in a straight line with the first end region 31 and has substantially the same length as the first end region 31. However, it may be provided at an angle with respect to the first end region 31, and may have a different length from the first end region 31. Further, the second end region 32 is a part of the electrode 3 in which the second end 3b is arranged near the center of the substrate 2 and extends from the second end 3b in a direction away from the center of the substrate 2. May be configured by.

第１の端部領域３１および第２の端部領域３２は、本実施形態では、図１に示されるように、第１の端部領域３１および第２の端部領域３２の単位長さ当たりの面積が本体領域３３の単位長さ当たりの面積よりも大きくなるように（本体領域３３よりも幅広に）形成されている。したがって、第２実施形態のＭＥＭＳ型半導体式ガス検知素子１００に関して以下で述べるように、第１の端部領域３１および第２の端部領域３２に導電膜６を容易に設けることができ、また広い接続面積を確保することができる。また、第１の端部領域３１および第２の端部領域３２は、本実施形態では、図１に示されるように、互いに接近して設けられている。より具体的には、第１の端部領域３１および第２の端部領域３２は、第１の端部領域３１と第２の端部領域３２との間の距離が、基板２（本体部２２１）の中心から外縁までの距離の１／２の距離よりも短くなるように、互いに接近して設けられている。したがって、第１の端部領域３１および第２の端部領域３２に電気的に接続するように設けられるガス感応部５をより小さく形成することができる。そして、ガス感応部５を小さく形成しても、電極３とガス感応部５との合成抵抗値が、電極３のほぼ全体の電気抵抗値とガス感応部５の電気抵抗値の並列合成抵抗値となるため、ガス感応部５のわずかな抵抗値変化を検出することができ、検知対象ガスの高い検出感度を確保することができる。ガス感応部５をより小さく形成するという観点から、第１の端部領域３１と第２の端部領域３２との間の距離は、たとえば、基板２の中心から外縁までの距離の２／３以下であることが好ましく、基板２の中心から外縁までの距離の１／２以下であることがより好ましく、基板２の中心から外縁までの距離の１／３以下であることがよりさらに好ましい。 The first end area 31 and the second end area 32, in this embodiment, per unit length of the first end area 31 and the second end area 32, as shown in FIG. Is formed so that the area of the main body region 33 is larger than the area per unit length of the main body region 33 (wider than the main body region 33). Therefore, as described below with respect to the MEMS type semiconductor gas detection element 100 of the second embodiment, the conductive film 6 can be easily provided in the first end region 31 and the second end region 32, and the conductive film 6 can be easily provided. A wide connection area can be secured. Further, the first end region 31 and the second end region 32 are provided close to each other in the present embodiment as shown in FIG. More specifically, in the first end region 31 and the second end region 32, the distance between the first end region 31 and the second end region 32 is the substrate 2 (main body portion). 221) are provided close to each other so as to be shorter than a distance of 1/2 of the distance from the center to the outer edge. Therefore, the gas-sensitive portion 5 provided so as to be electrically connected to the first end region 31 and the second end region 32 can be formed smaller. Even if the gas-sensitive portion 5 is formed small, the combined resistance value of the electrode 3 and the gas-sensitive portion 5 is the parallel combined resistance value of the electric resistance value of almost the entire electrode 3 and the electric resistance value of the gas-sensitive portion 5. Therefore, a slight change in the resistance value of the gas-sensitive unit 5 can be detected, and high detection sensitivity of the detection target gas can be ensured. From the viewpoint of forming the gas-sensitive portion 5 to be smaller, the distance between the first end region 31 and the second end region 32 is, for example, 2/3 of the distance from the center of the substrate 2 to the outer edge. It is preferably less than or equal to, more preferably 1/2 or less of the distance from the center of the substrate 2 to the outer edge, and even more preferably 1/3 or less of the distance from the center of the substrate 2 to the outer edge.

また、第１の端部領域３１および第２の端部領域３２は、本実施形態では、図１に示されるように、基板２（本体部２２１）の中心近傍まで延びている。より具体的には、第１の端部領域３１および第２の端部領域３２は、基板２の外縁までの距離の１／２の距離よりも短い距離まで、基板２の中心に接近して延びている。したがって、ガス感応部５は、基板２の中心近傍において、より小さく形成することができる。さらに、ガス感応部５が基板２の中心近傍にだけ設けられることで、ガス感応部５の端部の全体において機能層７を十分な厚さで形成することができるので、機能層７の機能をより高めることができる。ガス感応部５を基板２の中心近傍に設けるという観点から、第１の端部領域３１および第２の端部領域３２のそれぞれと基板２の中心との間の距離は、たとえば、基板２の中心から外縁までの距離の２／３以下であることが好ましく、基板２の中心から外縁までの距離の１／２以下であることがより好ましく、基板２の中心から外縁までの距離の１／３以下であることがよりさらに好ましい。 Further, in the present embodiment, the first end region 31 and the second end region 32 extend to the vicinity of the center of the substrate 2 (main body portion 221) as shown in FIG. More specifically, the first end region 31 and the second end region 32 approach the center of the substrate 2 to a distance shorter than half the distance to the outer edge of the substrate 2. It is extending. Therefore, the gas-sensitive portion 5 can be formed smaller in the vicinity of the center of the substrate 2. Further, since the gas-sensitive portion 5 is provided only near the center of the substrate 2, the functional layer 7 can be formed with a sufficient thickness in the entire end portion of the gas-sensitive portion 5, so that the function of the functional layer 7 can be formed. Can be further enhanced. From the viewpoint of providing the gas sensitive portion 5 near the center of the substrate 2, the distance between each of the first end region 31 and the second end region 32 and the center of the substrate 2 is, for example, the distance of the substrate 2. It is preferably 2/3 or less of the distance from the center to the outer edge, more preferably 1/2 or less of the distance from the center to the outer edge of the substrate 2, and 1 / of the distance from the center of the substrate 2 to the outer edge. It is more preferably 3 or less.

本体領域３３は、第１の端部領域３１と第２の端部領域３２とを接続する電極３の一部の領域である。本体領域３３は、第１の端部領域３１と第２の端部領域３２とを接続するように第１の端部領域３１と第２の端部領域３２との間に延びていれば、その配置は特に限定されることはない。本体領域３３は、本実施形態では、図１に示されるように、基板２（本体部２２１）上の第１の端部３ａと第２の端部３ｂとを結ぶ直線Ｓに対して垂直方向の一方側（第１の領域２２１ａ）と、基板２上の第１の端部３ａと第２の端部３ｂとを結ぶ直線Ｓに対して垂直方向の他方側（第２の領域２２１ｂ）とに延びている。本体領域３３が、基板２（本体部２２１）上の対向する２つの領域２２１ａ、２２１ｂに設けられることにより、ガス感応部５を加熱するために電極３（ヒータ４）を昇温しても、基板２がより均一に加熱されるので、基板２が熱により湾曲することが抑制される。 The main body region 33 is a partial region of the electrode 3 connecting the first end region 31 and the second end region 32. If the main body region 33 extends between the first end region 31 and the second end region 32 so as to connect the first end region 31 and the second end region 32, The arrangement is not particularly limited. In the present embodiment, the main body region 33 is in the direction perpendicular to the straight line S connecting the first end portion 3a and the second end portion 3b on the substrate 2 (main body portion 221) as shown in FIG. One side (first region 221a) and the other side (second region 221b) perpendicular to the straight line S connecting the first end 3a and the second end 3b on the substrate 2. Extends to. By providing the main body region 33 in the two opposing regions 221a and 221b on the substrate 2 (main body portion 221), even if the electrode 3 (heater 4) is heated in order to heat the gas sensitive portion 5, the temperature of the electrode 3 (heater 4) may be raised. Since the substrate 2 is heated more uniformly, it is possible to prevent the substrate 2 from being curved by heat.

本体領域３３は、本実施形態では、図１に示されるように、基板２（本体部２２１）の第１の領域２２１ａに設けられる第１の本体領域３３１と、基板２の第２の領域２２１ｂに設けられる第２の本体領域３３２と、第１の本体領域３３１と第２の本体領域３３２との間に設けられる中間領域３３３とを備えている。 In the present embodiment, the main body region 33 is a first main body region 331 provided in the first region 221a of the substrate 2 (main body portion 221) and a second region 221b of the substrate 2, as shown in FIG. A second main body region 332 provided in the above, and an intermediate region 333 provided between the first main body region 331 and the second main body region 332 are provided.

第１の本体領域３３１は、図１に示されるように、基板２（本体部２２１）の第１の領域２２１ａ上において、第１の端部領域３１の一方側の端部である第１の端部３ａとは反対側の他方側の端部（第１の近接部３ｃ）から中間領域３３３まで延びている。より具体的には、第１の本体領域３３１は、第１の端部領域３１の他方側の端部から、基板２の端部に（図中、上側に）向かって蛇行しながら延び、基板２の端縁に沿って延びた後、基板２の中心に向かって延び、中間領域３３３にまで延びている。それによって、第１の本体領域３３１は、第１の領域２２１ａ内において高い密度で配置されるので、長い配線長さを確保し、高い電気抵抗値を確保することができる。 As shown in FIG. 1, the first main body region 331 is a first end portion on one side of the first end region 31 on the first region 221a of the substrate 2 (main body portion 221). It extends from the other end (first proximity 3c) on the opposite side of the end 3a to the intermediate region 333. More specifically, the first main body region 331 extends from the other end of the first end region 31 toward the end of the substrate 2 (upward in the figure) while meandering to the substrate. After extending along the edge of 2, it extends toward the center of the substrate 2 and extends to the intermediate region 333. As a result, the first main body region 331 is arranged at a high density in the first region 221a, so that a long wiring length can be secured and a high electric resistance value can be secured.

第２の本体領域３３２は、図１に示されるように、基板２（本体部２２１）の第２の領域２２１ｂ上において、第２の端部領域３２の一方側の端部である第２の端部３ｂとは反対側の他方側の端部（第２の近接部３ｄ）から中間領域３３３まで延びている。より具体的には、第２の本体領域３３２は、第２の端部領域３２の他方側の端部から、基板２の端部に（図中、下側に）向かって蛇行しながら延び、基板２の端縁に沿って延びた後、基板２の中心に向かって延び、中間領域３３３にまで延びている。それによって、第２の本体領域３３２は、第２の領域２２１ｂ内において高い密度で配置されるので、長い配線長さを確保し、高い電気抵抗値を確保することができる。 As shown in FIG. 1, the second main body region 332 is a second end portion on one side of the second end region 32 on the second region 221b of the substrate 2 (main body portion 221). It extends from the other end (second proximity 3d) on the opposite side of the end 3b to the intermediate region 333. More specifically, the second main body region 332 extends from the other end of the second end region 32 to the end of the substrate 2 while meandering (downward in the figure). After extending along the edge of the substrate 2, it extends toward the center of the substrate 2 and extends to the intermediate region 333. As a result, the second main body region 332 is arranged at a high density in the second region 221b, so that a long wiring length can be secured and a high electric resistance value can be secured.

第１の本体領域３３１および第２の本体領域３３２は、本実施形態では、図１に示されるように、互いに略同一の長さに形成され、互いに略同一の電気抵抗を有している。それにより、ガス感応部５を加熱するために電極３（ヒータ４）を昇温しても、基板２がより均一に加熱されるので、基板２が熱により湾曲するのが抑制される。また、第１の本体領域３３１および第２の本体領域３３２は、基板２の略中心を中心として、互いに略点対象に配置されている。それにより、電極３（ヒータ４）を昇温した際に、基板２がよりさらに均一に加熱されるので、基板２が熱により湾曲するのがよりさらに抑制される。 In the present embodiment, the first main body region 331 and the second main body region 332 are formed to have substantially the same length and have substantially the same electrical resistance as each other, as shown in FIG. As a result, even if the temperature of the electrode 3 (heater 4) is raised to heat the gas-sensitive portion 5, the substrate 2 is heated more uniformly, so that the substrate 2 is suppressed from being curved by heat. Further, the first main body region 331 and the second main body region 332 are arranged at substantially point targets of each other with the substantially center of the substrate 2 as the center. As a result, when the temperature of the electrode 3 (heater 4) is raised, the substrate 2 is heated more uniformly, so that the substrate 2 is further suppressed from being curved by heat.

中間領域３３３は、図１に示されるように、第１の本体領域３３１と第２の本体領域３３２とを接続する。中間領域３３３は、基板２（本体部２２１）の第１の領域２２１ａと第２の領域２２１ｂとの間の境界において、第１の端部３ａと第２の端部３ｂとを結ぶ直線Ｓと交差（図示された例では直交）して、第１の領域２２１ａと第２の領域２２１ｂとの間に延びるように設けられている。本実施形態では、中間領域３３３の両側に設けられる第１の本体領域３３１および第２の本体領域３３２が互いに略同一の長さに形成されているので、中間領域３３３は、本体領域３３の延びる方向における本体領域３３の略中間の長さの位置にある。中間領域３３３は、基板２の略中心において、第１の端部領域３１および第２の端部領域３２の間に設けられている。第１の端部領域３１および第２の端部領域３２の間には、第１の本体領域３３１および第２の本体領域３３２が設けられることなく、中間領域３３３のみが設けられている。 As shown in FIG. 1, the intermediate region 333 connects the first main body region 331 and the second main body region 332. The intermediate region 333 is a straight line S connecting the first end portion 3a and the second end portion 3b at the boundary between the first region 221a and the second region 221b of the substrate 2 (main body portion 221). It is provided so as to intersect (orthogonally in the illustrated example) and extend between the first region 221a and the second region 221b. In the present embodiment, since the first main body region 331 and the second main body region 332 provided on both sides of the intermediate region 333 are formed to have substantially the same length as each other, the intermediate region 333 extends from the main body region 33. It is at a position approximately intermediate in length in the body region 33 in the direction. The intermediate region 333 is provided substantially in the center of the substrate 2 between the first end region 31 and the second end region 32. Between the first end region 31 and the second end region 32, only the intermediate region 333 is provided without the first main body region 331 and the second main body region 332.

ガス感応部５は、表面の吸着酸素と検知対象ガスとの化学反応に伴って電気抵抗が変化する部位である。ガス感応部５は、検知対象ガスの接触によって電気抵抗が変化する材料であれば、特に限定されることはなく、たとえば金属酸化物半導体を主成分とする材料により構成することができる。ガス感応部５は、図１および図２に示されるように、電極３に電気的に接続し、ヒータ４に熱的に接続するように基板２上に設けられる。ガス感応部５が電極３に電気的に接続するように設けられることで、電極３を介してガス感応部５の電気抵抗の変化を検出することができる。また、ガス感応部５がヒータ４に熱的に接続するように設けられることで、ヒータ４を介してガス感応部５を検知対象ガスの検知に適した温度に加熱することができる。 The gas sensitive portion 5 is a portion where the electric resistance changes with the chemical reaction between the adsorbed oxygen on the surface and the gas to be detected. The gas sensitive portion 5 is not particularly limited as long as it is a material whose electric resistance changes by contact with the gas to be detected, and can be made of, for example, a material containing a metal oxide semiconductor as a main component. As shown in FIGS. 1 and 2, the gas sensitive portion 5 is provided on the substrate 2 so as to be electrically connected to the electrode 3 and thermally connected to the heater 4. By providing the gas-sensitive unit 5 so as to be electrically connected to the electrode 3, it is possible to detect a change in the electrical resistance of the gas-sensitive unit 5 via the electrode 3. Further, by providing the gas sensitive unit 5 so as to be thermally connected to the heater 4, the gas sensitive unit 5 can be heated to a temperature suitable for detecting the gas to be detected via the heater 4.

ガス感応部５の金属酸化物半導体としては、吸着酸素と検知対象ガスとの化学反応に伴って電気抵抗が変化するものであれば、特に限定されることはない。たとえば、ガス感応部５の金属酸化物半導体としては、酸素吸着、および吸着酸素とガス成分との化学反応を促進し、ガス検知感度を向上させるという観点から、ｎ型半導体を用いることが好ましく、酸化スズ、酸化インジウム、酸化亜鉛および酸化タングステンの中から選択される少なくとも１種を含む金属酸化物半導体を用いることがさらに好ましく、酸化スズおよび酸化インジウムの中から選択される少なくとも１種を含む金属酸化物半導体を用いることがよりさらに好ましい。 The metal oxide semiconductor of the gas sensitive portion 5 is not particularly limited as long as the electric resistance changes with the chemical reaction between the adsorbed oxygen and the gas to be detected. For example, as the metal oxide semiconductor of the gas sensitive portion 5, it is preferable to use an n-type semiconductor from the viewpoint of promoting oxygen adsorption and the chemical reaction between the adsorbed oxygen and the gas component and improving the gas detection sensitivity. It is more preferable to use a metal oxide semiconductor containing at least one selected from tin oxide, indium oxide, zinc oxide and tungsten oxide, and a metal containing at least one selected from tin oxide and indium oxide. It is even more preferable to use an oxide semiconductor.

ガス感応部５の金属酸化物半導体は、電気抵抗を調整するために、ドナーとして金属元素が添加されていてもよい。添加される金属元素としては、金属酸化物半導体中にドナーとして添加可能であり、金属酸化物半導体の電気抵抗を調整することが可能であれば、特に限定されることはないが、たとえば、アンチモン、ニオブおよびタングステンの中から選択される少なくとも１種が例示される。また、ガス感応部５の金属酸化物半導体は、電気抵抗を調整するために、金属酸化物半導体中に酸素欠損が導入されてもよい。金属元素濃度や酸素欠損濃度は、要求される電気抵抗に応じて、適宜設定することができる。 The metal oxide semiconductor of the gas sensitive portion 5 may be added with a metal element as a donor in order to adjust the electric resistance. The metal element to be added is not particularly limited as long as it can be added as a donor in the metal oxide semiconductor and the electric resistance of the metal oxide semiconductor can be adjusted, but is not particularly limited, for example, antimony. , At least one selected from niobium and tungsten is exemplified. Further, in the metal oxide semiconductor of the gas sensitive portion 5, oxygen deficiency may be introduced into the metal oxide semiconductor in order to adjust the electric resistance. The metal element concentration and the oxygen deficiency concentration can be appropriately set according to the required electrical resistance.

ガス感応部５は、基板２上において、電極３によって抵抗変化を検出できるように、またヒータ４によって加熱されるように設けられればよく、その形成方法は特に限定されない。ガス感応部５は、たとえば、金属酸化物半導体の微粉体を溶媒に混ぜてペースト状としたものを、予め電極３およびヒータ４が設けられた基板２上に塗布して乾燥させることにより形成することが可能である。 The gas-sensitive portion 5 may be provided on the substrate 2 so that the resistance change can be detected by the electrode 3 and is heated by the heater 4, and the forming method thereof is not particularly limited. The gas-sensitive portion 5 is formed, for example, by mixing a fine powder of a metal oxide semiconductor with a solvent to form a paste, which is applied onto a substrate 2 provided with an electrode 3 and a heater 4 in advance and dried. It is possible.

ガス感応部５に任意で被覆するように設けられる機能層７は、ガス感応部５における検知対象ガスの選択性を向上させる機能や、ガス感応部５の劣化を抑制する機能など、ガス感応部５のガス検知特性を向上させる機能を有する層である。機能層７は、ガス感応部５を被覆するようにガス感応部５上に設けられる。本実施形態のＭＥＭＳ型半導体式ガス検知素子１では、ガス感応部５が、基板２の一部に設けられている。それにより、ガス感応部５上に設けられる機能層７は、ガス感応部５の端部領域においても、必要な厚さで形成することができるので、機能の低下を抑制することができる。したがって、本実施形態のＭＥＭＳ型半導体式ガス検知素子１では、ガス感応部５が基板２の全体に設けられる場合と比べて、機能層７の全体の機能を向上させることができる。 The functional layer 7 provided so as to optionally cover the gas sensitive portion 5 is a gas sensitive portion such as a function of improving the selectivity of the detection target gas in the gas sensitive portion 5 and a function of suppressing deterioration of the gas sensitive portion 5. 5 is a layer having a function of improving the gas detection characteristic. The functional layer 7 is provided on the gas sensitive portion 5 so as to cover the gas sensitive portion 5. In the MEMS type semiconductor type gas detection element 1 of the present embodiment, the gas sensitive portion 5 is provided on a part of the substrate 2. As a result, the functional layer 7 provided on the gas-sensitive portion 5 can be formed with a required thickness even in the end region of the gas-sensitive portion 5, so that deterioration of the function can be suppressed. Therefore, in the MEMS type semiconductor type gas detection element 1 of the present embodiment, the overall function of the functional layer 7 can be improved as compared with the case where the gas sensitive portion 5 is provided on the entire substrate 2.

本実施形態では、機能層７として、ガス感応部５の劣化を抑制し、ガス感応部５を保護する機能を有する２種類の層（以下、第１機能層、第２機能層という）が例示される。ただし、機能層７としては、ガス感応部５のガス検知特性を向上させる機能を有するものであれば、特に限定されることはなく、半導体式ガス検知素子において、ガス感応部を被覆することでガス感応部のガス検知特性を向上させる機能を有する公知の層を採用することができる。 In the present embodiment, as the functional layer 7, two types of layers having a function of suppressing deterioration of the gas-sensitive portion 5 and protecting the gas-sensitive portion 5 (hereinafter, referred to as a first functional layer and a second functional layer) are exemplified. Will be done. However, the functional layer 7 is not particularly limited as long as it has a function of improving the gas detection characteristics of the gas sensitive portion 5, and the semiconductor type gas detection element may be covered with the gas sensitive portion. A known layer having a function of improving the gas detection characteristics of the gas sensitive portion can be adopted.

第１の例である第１機能層は、環境雰囲気中に含まれる検知対象ガス以外の特定のガス成分（たとえば有機シリコーンガス）からガス感応部５を保護し、ガス感応部５の耐久性を向上させる。第１機能層は、たとえば、環境雰囲気中に含まれる有機シリコーンガス（たとえば、ヘキサメチルジシロキサンなど）がガス感応部５に付着することによってガス感応部５が被毒する（ガス感応部５の検知感度が変化してＭＥＭＳ型半導体式ガス検知素子１が誤作動する）のを抑制する。 The first functional layer, which is the first example, protects the gas sensitive portion 5 from specific gas components (for example, organic silicone gas) other than the detection target gas contained in the environmental atmosphere, and improves the durability of the gas sensitive portion 5. Improve. In the first functional layer, for example, the gas sensitive portion 5 is poisoned by the organic silicone gas (for example, hexamethyldisiloxane) contained in the environmental atmosphere adhering to the gas sensitive portion 5 (the gas sensitive portion 5). The detection sensitivity changes and the MEMS type semiconductor gas detection element 1 malfunctions).

第１機能層は、ガス感応部５を保護し、ガス感応部５の耐久性を向上させるという目的のために、金属酸化物半導体に金属酸化物が担持されて形成される。金属酸化物半導体としては、特に限定されることはなく、たとえば、酸化スズ、酸化インジウム、酸化亜鉛および酸化タングステンの中から選択される少なくとも１種を含む金属酸化物半導体を用いることができる。金属酸化物としては、特定のガス成分からガス感応部５を保護し得る金属酸化物であり、たとえば、酸化クロム、酸化パラジウム、酸化コバルト、酸化鉄、酸化ロジウム、酸化銅、酸化セリウム、酸化白金、酸化タングステンおよび酸化ランタンの中から選択される少なくとも１種を用いることができる。金属酸化物は、上に例示された中でも、ガス感応部５の劣化をよりさらに抑制する観点から、酸化クロムおよび酸化パラジウムの中から選択される少なくとも１種であることが好ましい。 The first functional layer is formed by supporting a metal oxide on a metal oxide semiconductor for the purpose of protecting the gas-sensitive portion 5 and improving the durability of the gas-sensitive portion 5. The metal oxide semiconductor is not particularly limited, and for example, a metal oxide semiconductor containing at least one selected from tin oxide, indium oxide, zinc oxide, and tungsten oxide can be used. The metal oxide is a metal oxide that can protect the gas-sensitive portion 5 from a specific gas component, and is, for example, chromium oxide, palladium oxide, cobalt oxide, iron oxide, rhodium oxide, copper oxide, cerium oxide, and platinum oxide. , Tungsten oxide and lanthanum oxide can be selected from at least one. Among the above-exemplified metal oxides, it is preferable that the metal oxide is at least one selected from chromium oxide and palladium oxide from the viewpoint of further suppressing the deterioration of the gas sensitive portion 5.

第１機能層は、特定のガス成分からガス感応部５を保護し、ガス感応部５の耐久性を向上させることができれば、その形成方法は特に限定されない。第１機能層は、たとえば、金属酸化物半導体の微粉体と金属酸化物の微粉体との混合物を溶媒に混ぜてペースト状としたものをガス感応部５に塗布して乾燥させることによって形成することができる。 As long as the first functional layer can protect the gas sensitive portion 5 from a specific gas component and improve the durability of the gas sensitive portion 5, the forming method thereof is not particularly limited. The first functional layer is formed, for example, by mixing a mixture of a fine powder of a metal oxide semiconductor and a fine powder of a metal oxide with a solvent to form a paste, which is applied to the gas-sensitive portion 5 and dried. be able to.

第２の例である第２機能層は、第１機能層と同様の目的のために、絶縁性酸化物により構成される。第２機能層は、絶縁性酸化物により特定のガス成分を捕捉することで、ガス感応部５を保護する。また、第２機能層が絶縁性酸化物により構成されることで、第２機能層中に電流が流れることが抑制され、検知対象ガス検知時のガス感応部５の抵抗値変化に及ぼす影響を抑えることができるので、検知対象ガスの検知感度が低下するのを抑えることができる。絶縁性酸化物としては、特に限定されることはないが、たとえば酸化アルミニウムおよび酸化シリコンの中から選択される少なくとも１種が例示される。 The second functional layer, which is the second example, is composed of an insulating oxide for the same purpose as the first functional layer. The second functional layer protects the gas sensitive portion 5 by capturing a specific gas component with an insulating oxide. Further, since the second functional layer is composed of the insulating oxide, the current is suppressed from flowing in the second functional layer, and the influence on the resistance value change of the gas sensitive portion 5 at the time of detecting the gas to be detected is affected. Since it can be suppressed, it is possible to suppress a decrease in the detection sensitivity of the gas to be detected. The insulating oxide is not particularly limited, and examples thereof include at least one selected from aluminum oxide and silicon oxide.

第２機能層は、絶縁性酸化物に、酸化活性を有する金属酸化物が担持されて形成されてもよい。第２機能層は、酸化活性を有する金属酸化物が絶縁性酸化物に担持されて形成されることにより、ガス感応部５の劣化をより抑制することができる。酸化活性を有する金属酸化物としては、たとえば、酸化クロム、酸化パラジウム、酸化コバルト、酸化鉄、酸化ロジウム、酸化銅、酸化セリウム、酸化白金、酸化タングステンおよび酸化ランタンの中から選択される少なくとも１種が例示される。金属酸化物は、上に例示された中でも、ガス感応部５の劣化をよりさらに抑制する観点から、酸化クロムおよび酸化パラジウムの中から選択される少なくとも１種であることが好ましい。 The second functional layer may be formed by supporting a metal oxide having oxidative activity on an insulating oxide. The second functional layer is formed by supporting a metal oxide having oxidative activity on an insulating oxide, so that deterioration of the gas-sensitive portion 5 can be further suppressed. As the metal oxide having oxidative activity, for example, at least one selected from chromium oxide, palladium oxide, cobalt oxide, iron oxide, rhodium oxide, copper oxide, cerium oxide, platinum oxide, tungsten oxide and lanthanum oxide. Is exemplified. Among the above-exemplified metal oxides, it is preferable that the metal oxide is at least one selected from chromium oxide and palladium oxide from the viewpoint of further suppressing the deterioration of the gas sensitive portion 5.

第２機能層は、特定のガス成分からガス感応部５を保護し、ガス感応部５の耐久性を向上させることができれば、その形成方法は特に限定されない。第２機能層は、たとえば、絶縁性酸化物の微粉体と金属酸化物の微粉体との混合物を溶媒に混ぜてペースト状としたものをガス感応部５に塗布して乾燥させることによって形成することができる。 The method for forming the second functional layer is not particularly limited as long as it can protect the gas-sensitive portion 5 from a specific gas component and improve the durability of the gas-sensitive portion 5. The second functional layer is formed, for example, by mixing a mixture of a fine powder of an insulating oxide and a fine powder of a metal oxide with a solvent to form a paste, which is applied to the gas-sensitive portion 5 and dried. be able to.

導電膜６は、導電性を有し、電極３とガス感応部５とを電気的に接続する。導電膜６の導電性（または電気抵抗）は、導電膜６を介して電極３によりガス感応部５の抵抗値変化を検出することができればよく、特に限定されることはないが、たとえばガス感応部５の導電性よりも高い（またはガス感応部５の電気抵抗よりも低い）ことが好ましい。また、導電膜６は、電極３と比較してガス感応部５に対して高い密着性を有し、また好ましくはガス感応部５と比較して電極３に対して高い密着性を有し、電極３とガス感応部５との間に介在して、電極３とガス感応部５とを互いに接続する。電極３と比較してガス感応部５に対する密着性が高い導電膜６を介して電極３とガス感応部５とが接続されることで、電極３に対するガス感応部５の密着性を高めることができる。それによって、電極３とガス感応部５との間に良好な電気接続を確保することができ、検知対象ガスがガス感応部５に接触した際に生じるガス感応部５の抵抗値の変化をより正確に検知することができる。さらに、ＭＥＭＳ型半導体式ガス検知素子１のガス検知能力の経時的な変化を抑制し、たとえば高温高湿環境下に曝された場合に生じる経時的なガス検知感度の劣化を抑制することができる。 The conductive film 6 has conductivity and electrically connects the electrode 3 and the gas sensitive portion 5. The conductivity (or electrical resistance) of the conductive film 6 is not particularly limited as long as the change in the resistance value of the gas sensitive portion 5 can be detected by the electrode 3 via the conductive film 6, but is not particularly limited, for example, gas sensitivity. It is preferably higher than the conductivity of the portion 5 (or lower than the electrical resistance of the gas sensitive portion 5). Further, the conductive film 6 has higher adhesion to the gas-sensitive portion 5 as compared with the electrode 3, and preferably has higher adhesion to the electrode 3 as compared with the gas-sensitive portion 5. The electrode 3 and the gas sensitive portion 5 are connected to each other by interposing between the electrode 3 and the gas sensitive portion 5. By connecting the electrode 3 and the gas-sensitive portion 5 via the conductive film 6, which has higher adhesion to the gas-sensitive portion 5 than the electrode 3, the adhesion of the gas-sensitive portion 5 to the electrode 3 can be improved. can. As a result, a good electrical connection can be secured between the electrode 3 and the gas-sensitive unit 5, and the change in the resistance value of the gas-sensitive unit 5 that occurs when the gas to be detected comes into contact with the gas-sensitive unit 5 can be further increased. It can be detected accurately. Further, it is possible to suppress a change in the gas detection ability of the MEMS type semiconductor type gas detection element 1 over time, and to suppress a deterioration in gas detection sensitivity over time that occurs when exposed to a high temperature and high humidity environment, for example. ..

導電膜６は、導電性を有し、電極３と比較してガス感応部５に対する密着性が高ければよく、その構成材料は特に限定されることはない。本実施形態では、導電膜６は、ガス感応部５に含まれる金属酸化物半導体の金属元素と同一の金属元素を含む金属酸化物半導体を主成分として形成される。具体的には、たとえばガス感応部５の主成分が酸化スズである場合、導電膜６は酸化スズを主成分として含み、ガス感応部５の主成分が酸化インジウムである場合、導電膜６は酸化インジウムを主成分として含む。ガス感応部５に含まれる金属酸化物半導体の金属元素と同一の金属元素を含む金属酸化物半導体を主成分として導電膜６が形成されることにより、ガス感応部５と導電膜６とが互いに馴染みやすく、ガス感応部５と導電膜６との間の密着性をより高めることができる。導電膜６の膜厚は、特に限定されることはなく、電極３とガス感応部５とを接続することができるように適宜設定可能である。 The conductive film 6 is not particularly limited as long as it has conductivity and has higher adhesion to the gas-sensitive portion 5 than the electrode 3. In the present embodiment, the conductive film 6 is formed mainly of a metal oxide semiconductor containing the same metal element as the metal element of the metal oxide semiconductor contained in the gas sensitive portion 5. Specifically, for example, when the main component of the gas-sensitive portion 5 is tin oxide, the conductive film 6 contains tin oxide as the main component, and when the main component of the gas-sensitive portion 5 is indium oxide, the conductive film 6 is Contains indium oxide as the main component. By forming the conductive film 6 mainly containing a metal oxide semiconductor containing the same metal element as the metal element of the metal oxide semiconductor contained in the gas sensitive portion 5, the gas sensitive portion 5 and the conductive film 6 are mutually connected. It is easy to get used to, and the adhesion between the gas sensitive portion 5 and the conductive film 6 can be further improved. The film thickness of the conductive film 6 is not particularly limited, and can be appropriately set so that the electrode 3 and the gas sensitive portion 5 can be connected.

導電膜６は、導電性を有し、電極３と比較してガス感応部５に対する密着性が高くなるように形成することができれば、その形成方法は特に限定されない。本実施形態では、導電膜６は、スパッタリングや真空蒸着により形成することができる。導電膜６は、スパッタリングや真空蒸着により形成されることで、塗布などにより形成される場合と比べて、より緻密な膜として形成される。導電膜６は、より緻密な膜として形成されることで、ガス感応部５に対する密着性をより高め、またガス感応部５とは反対側の電極３や後述する絶縁膜８に対する密着性をより高めることができる。導電膜６は、たとえば、基板２を３００℃などの高温で加熱しながら、ターゲットである酸化スズや酸化インジウムなどの金属酸化物半導体をアルゴンイオンでスパッタリングすることにより、金属酸化物半導体を主成分として形成することができる。この方法によれば、ガス感応部５に対する密着性を高めるだけでなく、金属酸化物半導体中に酸素欠損を生じさせて導電性を高めるとともに、電極３や絶縁膜８に対する密着性をより高めることができる。なお、導電膜６は、アンチモン、ニオブ、タングステンなどのドナーを添加することによって、導電性を高めてもよい（電気抵抗を下げてもよい）。 The conductive film 6 is not particularly limited as long as it has conductivity and can be formed so as to have higher adhesion to the gas-sensitive portion 5 than the electrode 3. In the present embodiment, the conductive film 6 can be formed by sputtering or vacuum deposition. By forming the conductive film 6 by sputtering or vacuum deposition, the conductive film 6 is formed as a denser film as compared with the case where it is formed by coating or the like. By forming the conductive film 6 as a denser film, the adhesion to the gas-sensitive portion 5 is further enhanced, and the adhesion to the electrode 3 on the opposite side of the gas-sensitive portion 5 and the insulating film 8 described later is further improved. Can be increased. The conductive film 6 is mainly composed of a metal oxide semiconductor by, for example, heating a substrate 2 at a high temperature such as 300 ° C. and sputtering a metal oxide semiconductor such as tin oxide or indium oxide as a target with argon ions. Can be formed as. According to this method, not only the adhesion to the gas-sensitive portion 5 is enhanced, but also oxygen deficiency is generated in the metal oxide semiconductor to enhance the conductivity, and the adhesion to the electrode 3 and the insulating film 8 is further enhanced. Can be done. The conductive film 6 may be increased in conductivity (or may be reduced in electrical resistance) by adding donors such as antimony, niobium, and tungsten.

導電膜６は、図１および図２に示されるように、電極３の経路とは異なる（よりも短い）経路で電極３を電気的に短絡させないように、電極３の少なくとも一部の上面に接続される。この場合、電極３の電気抵抗値とガス感応部５の電気抵抗値との合成抵抗値は、導電膜６による電極３の短絡が抑制されることで、ガス感応部５が接続する電極３の全体の電気抵抗値とガス感応部５の電気抵抗値との並列合成抵抗値となる。これにより、導電膜６を設けても、電極３の電気抵抗値とガス感応部５の電気抵抗値との合成抵抗値は、ガス感応部５の電気抵抗値の変化に応じて大きく変化するので、検知対象ガスに対して高い感度を得ることができる。さらに、本実施形態のように電極３がヒータ４を兼ねるような場合には、導電膜６によるヒータ４の短絡が抑制されることで、ヒータ４を正常または正常に近い状態で機能させることができる。 As shown in FIGS. 1 and 2, the conductive film 6 is applied to the upper surface of at least a part of the electrode 3 so as not to electrically short-circuit the electrode 3 by a path different from (shorter than) the path of the electrode 3. Be connected. In this case, the combined resistance value of the electric resistance value of the electrode 3 and the electric resistance value of the gas sensitive portion 5 is the combined resistance value of the electrode 3 to which the gas sensitive portion 5 is connected by suppressing the short circuit of the electrode 3 due to the conductive film 6. It is a parallel combined resistance value of the entire electric resistance value and the electric resistance value of the gas sensitive portion 5. As a result, even if the conductive film 6 is provided, the combined resistance value of the electric resistance value of the electrode 3 and the electric resistance value of the gas sensitive portion 5 changes greatly according to the change of the electric resistance value of the gas sensitive portion 5. , High sensitivity to the detection target gas can be obtained. Further, when the electrode 3 also serves as the heater 4 as in the present embodiment, the short circuit of the heater 4 due to the conductive film 6 is suppressed, so that the heater 4 can function in a normal or near-normal state. can.

ここで、「電極３の経路とは異なる経路で電極３を短絡させる」とは、たとえば基板２上の電極３の配線経路とは異なる経路で導電膜６が配置されて、その導電膜６が、電極３の配線経路とは異なる経路で電極３の一部同士を橋渡しするようにして短絡させることを意味する。なお、「電極３の経路とは異なる経路で電極３を電気的に短絡させない」とは、電極３の経路の少なくとも一部に亘って短絡させないことを意味し、必ずしも電極３の経路のいずれにおいても短絡させないことを意味するものではない。ただし、検知対象ガスに対して高い検知感度を得るためには、電極３の経路の全体に亘って短絡させないことが好ましい。また、本実施形態のように電極３がヒータ４を兼ねるような場合には、ヒータ４を正常に機能させるために、ヒータ４（電極３）の経路の全体に亘って短絡させないことが好ましい。 Here, "short-circuiting the electrode 3 by a path different from the path of the electrode 3" means that, for example, the conductive film 6 is arranged in a path different from the wiring path of the electrode 3 on the substrate 2, and the conductive film 6 is arranged. It means that a part of the electrodes 3 is short-circuited so as to bridge each other by a route different from the wiring route of the electrodes 3. In addition, "not electrically short-circuiting the electrode 3 by a path different from the path of the electrode 3" means not short-circuiting over at least a part of the path of the electrode 3, and is not necessarily short-circuited in any of the paths of the electrode 3. Does not mean that it will not be short-circuited. However, in order to obtain high detection sensitivity with respect to the detection target gas, it is preferable not to short-circuit the entire path of the electrode 3. Further, when the electrode 3 also serves as the heater 4 as in the present embodiment, it is preferable not to short-circuit the entire path of the heater 4 (electrode 3) in order for the heater 4 to function normally.

導電膜６は、上述したように、電極３の経路とは異なる経路で電極３を電気的に短絡させないように、電極３の少なくとも一部の上面に接続されていればよく、その配置は特に限定されない。導電膜６は、本実施形態では、図１および図２に示されるように、電極３の上面にのみ接続されている。より具体的には、導電膜６は、電極３の全長および全幅に亘って、電極３の上面のみに接続されている。これにより、導電膜６は、ガス感応部５との間の接続面積をより増やすことで、電極３の全体に対するガス感応部５の密着性をより高めながらも、電極３の経路とは異なる経路で電極３を電気的に短絡させない。ＭＥＭＳ型半導体式ガス検知素子１では、電極３の全体に対するガス感応部５の密着性をより高めることで、電極３とガス感応部５との間により良好な電気接続を確保することができるので、検知対象ガスがガス感応部５に接触した際に生じるガス感応部５の抵抗値の変化をより正確に検知することができる。さらに、ＭＥＭＳ型半導体式ガス検知素子１のガス検知能力の経時的な変化をより抑制し、たとえば高温高湿環境下に曝された場合に生じる経時的なガス検知感度の劣化をより抑制することができる。なお、導電膜６は、電極３の経路とは異なる経路で電極３を電気的に短絡させないように電極３の少なくとも一部の上面に接続されていればよく、たとえば、電極３の上面からはみ出るように設けられていてもよい。 As described above, the conductive film 6 may be connected to the upper surface of at least a part of the electrode 3 so as not to electrically short-circuit the electrode 3 by a path different from the path of the electrode 3, and the arrangement thereof is particularly high. Not limited. In this embodiment, the conductive film 6 is connected only to the upper surface of the electrode 3 as shown in FIGS. 1 and 2. More specifically, the conductive film 6 is connected only to the upper surface of the electrode 3 over the entire length and width of the electrode 3. As a result, the conductive film 6 has a path different from that of the electrode 3 while further increasing the adhesion of the gas sensitive portion 5 to the entire electrode 3 by increasing the connection area with the gas sensitive portion 5. The electrode 3 is not electrically short-circuited. In the MEMS type semiconductor type gas detection element 1, by further enhancing the adhesion of the gas sensitive portion 5 to the entire electrode 3, it is possible to secure a better electrical connection between the electrode 3 and the gas sensitive portion 5. It is possible to more accurately detect the change in the resistance value of the gas sensitive unit 5 that occurs when the detection target gas comes into contact with the gas sensitive unit 5. Further, it is possible to further suppress the change in the gas detection ability of the MEMS type semiconductor gas detection element 1 over time, and further suppress the deterioration of the gas detection sensitivity over time that occurs when exposed to a high temperature and high humidity environment, for example. Can be done. The conductive film 6 may be connected to the upper surface of at least a part of the electrode 3 so as not to electrically short-circuit the electrode 3 by a path different from the path of the electrode 3, and for example, the conductive film 6 protrudes from the upper surface of the electrode 3. It may be provided as follows.

＜第２実施形態＞
つぎに、図４および図５を参照して、第２実施形態に係るＭＥＭＳ型半導体式ガス検知素子１００を説明する。以下では、第１実施形態に係るＭＥＭＳ型半導体式ガス検知素子１と異なる構成（主に導電膜６および絶縁膜８）を中心に説明し、他の共通する構成の説明は省略する。また、図４および図５においては、第１実施形態に係るＭＥＭＳ型半導体式ガス検知素子１の構成要素と同一の機能を有する構成要素を同じ参照符号で示している。 <Second Embodiment>
Next, the MEMS type semiconductor gas detection element 100 according to the second embodiment will be described with reference to FIGS. 4 and 5. Hereinafter, the configuration (mainly the conductive film 6 and the insulating film 8) different from the MEMS type semiconductor gas detection element 1 according to the first embodiment will be mainly described, and the description of other common configurations will be omitted. Further, in FIGS. 4 and 5, components having the same functions as the components of the MEMS type semiconductor gas detection element 1 according to the first embodiment are indicated by the same reference numerals.

本実施形態のＭＥＭＳ型半導体式ガス検知素子１００の導電膜６もまた、第１実施形態における導電膜６と同様に、電極３の経路とは異なる（よりも短い）経路で電極３を電気的に短絡させないように、電極３の少なくとも一部の上面に接続される。本実施形態では、導電膜６は、図４および図５に示されるように、電極３の第１の端部領域３１および第２の端部領域３２に接続されている。これにより、ガス感応部５が第１の端部領域３１および第２の端部領域３２に電気的に接続することとなり、電極３とガス感応部５との合成抵抗値が、電極３の長さ方向に亘って全体の電気抵抗値とガス感応部５の電気抵抗値との並列合成抵抗値となる。これにより、電極３とガス感応部５との合成抵抗値は、ガス感応部５の電気抵抗値の変化に応じて大きく変化するので、検知対象ガスに対して高い感度を得ることができる。なお、導電膜６は、図示された例では、電極３の第１の端部領域３１および第２の端部領域３２の上面にのみ接続されている。しかし、導電膜６は、電極３を短絡させないように電極３に接続されていれば、図示された例に限定されることはなく、第１の端部領域３１および第２の端部領域３２からはみ出るように設けられていてもよい。 Similarly to the conductive film 6 in the first embodiment, the conductive film 6 of the MEMS type semiconductor type gas detection element 100 of the present embodiment also electrically connects the electrode 3 with a path different from (shorter than) the path of the electrode 3. It is connected to the upper surface of at least a part of the electrode 3 so as not to cause a short circuit. In this embodiment, the conductive film 6 is connected to the first end region 31 and the second end region 32 of the electrode 3, as shown in FIGS. 4 and 5. As a result, the gas-sensitive portion 5 is electrically connected to the first end region 31 and the second end region 32, and the combined resistance value of the electrode 3 and the gas-sensitive portion 5 is the length of the electrode 3. It becomes the parallel combined resistance value of the total electric resistance value and the electric resistance value of the gas sensitive portion 5 over the vertical direction. As a result, the combined resistance value of the electrode 3 and the gas-sensitive unit 5 changes greatly according to the change in the electric resistance value of the gas-sensitive unit 5, so that high sensitivity to the detection target gas can be obtained. In the illustrated example, the conductive film 6 is connected only to the upper surface of the first end region 31 and the second end region 32 of the electrode 3. However, the conductive film 6 is not limited to the illustrated example as long as it is connected to the electrode 3 so as not to short-circuit the electrode 3, and the first end region 31 and the second end region 32 are not limited. It may be provided so as to protrude from the outside.

より具体的に説明すると、導電膜６は、本実施形態では、図４および図５に示されるように、第１の端部領域３１に接続される第１の導電膜６１と、第２の端部領域３２に接続される第２の導電膜６２とを備えている。第１の導電膜６１および第２の導電膜６２は、電極３を介して互いに電気的に接続されている以外には、互いに電気的に分離するように設けられている。これによって、導電膜６は、電極３の経路とは異なる経路で電極３を電気的に短絡させない。 More specifically, in the present embodiment, the conductive film 6 has a first conductive film 61 connected to the first end region 31 and a second conductive film 61 as shown in FIGS. 4 and 5. It includes a second conductive film 62 connected to the end region 32. The first conductive film 61 and the second conductive film 62 are provided so as to be electrically separated from each other except that they are electrically connected to each other via the electrode 3. As a result, the conductive film 6 does not electrically short-circuit the electrode 3 in a path different from that of the electrode 3.

第１の導電膜６１および第２の導電膜６２はそれぞれ、図４および図５に示されるように、電極３と接続する電極接続部６１ａ、６２ａと、ガス感応部５と接続するガス感応部接続部６１ｂ、６２ｂとを備えている。電極接続部６１ａ、６２ａは、ガス感応部５側から電極３（第１の端部領域３１および第２の端部領域３２）に向かって、後述する絶縁膜８および接着層９に設けられた貫通孔を通って延びるように設けられている。電極接続部６１ａ、６２ａの一端は、電極３の第１の端部領域３１および第２の端部領域３２に接続され、電極接続部６１ａ、６２ａの他端は、ガス感応部接続部６１ｂ、６２ｂに接続される。ガス感応部接続部６１ｂ、６２ｂは、基板２（本体部２２１）の表面に沿って、電極接続部６１ａ、６２ａの電極３との接続面積よりも広く、また電極３の表面積よりも広い面積で面状に広がるように設けられている。ガス感応部接続部６１ｂ、６２ｂの一方の面は、ガス感応部５に接続され、ガス感応部接続部６１ｂ、６２ｂの他方の面は、電極接続部６１ａ、６２ａおよび後述する絶縁膜８に接続される。このように、導電膜６の少なくとも一部が、絶縁膜８の上に設けられることにより、電極３を短絡させることなく導電膜６を基板２の表面に沿って面状に広がるように設けることが可能になる。それによって、ガス感応部５と導電膜６との間の接続面積を大きくして、ガス感応部５と導電膜６との間の密着力を向上させ、結果として、電極３とガス感応部５との間の密着性をより向上させることができる。さらに、電極接続部６１ａ、６２ａの電極３との接続面積よりも広く、また電極３の表面積よりも広い面積を有するガス感応部接続部６１ｂ、６２ｂがガス感応部５と接続することで、導電膜６とガス感応部５との導通、ひいては電極３とガス感応部５との導通をより確実に確保することができ、ガス感応部５の抵抗値変化をより確実に検知することができる。さらに、ＭＥＭＳ型半導体式ガス検知素子１００のガス検知能力の経時的な変化をより抑制し、たとえば高温高湿環境下に曝された場合に生じる経時的なガス検知感度の劣化をより抑制することができる。ガス感応部接続部６１ｂ、６２ｂはそれぞれ、基板２（本体部２２１）の略半分の面積を有し、略半円状に形成されている。そして、ガス感応部接続部６１ｂ、６２ｂは、電極３の第１の端部３ａと第２の端部３ｂとを結ぶ直線Ｓに沿って互いに対向するように、それぞれの略半円の直線部分同士の間に設けられたギャップＧを介して互いに離間して設けられている。 As shown in FIGS. 4 and 5, the first conductive film 61 and the second conductive film 62 have an electrode connecting portion 61a and 62a connected to the electrode 3 and a gas sensitive portion connected to the gas sensitive portion 5, respectively. It is provided with connecting portions 61b and 62b. The electrode connecting portions 61a and 62a are provided on the insulating film 8 and the adhesive layer 9 described later from the gas sensitive portion 5 side toward the electrode 3 (first end region 31 and second end region 32). It is provided so as to extend through the through hole. One end of the electrode connecting portions 61a and 62a is connected to the first end region 31 and the second end region 32 of the electrode 3, and the other ends of the electrode connecting portions 61a and 62a are connected to the gas sensitive portion connecting portion 61b. It is connected to 62b. The gas-sensitive portion connecting portions 61b and 62b have an area along the surface of the substrate 2 (main body portion 221) that is wider than the connection area of the electrode connecting portions 61a and 62a with the electrode 3 and larger than the surface area of the electrode 3. It is provided so as to spread out in a plane shape. One surface of the gas-sensitive portion connecting portions 61b and 62b is connected to the gas-sensitive portion 5, and the other surface of the gas-sensitive portion connecting portions 61b and 62b is connected to the electrode connecting portions 61a and 62a and the insulating film 8 described later. Will be done. In this way, by providing at least a part of the conductive film 6 on the insulating film 8, the conductive film 6 is provided so as to spread in a plane along the surface of the substrate 2 without short-circuiting the electrodes 3. Will be possible. As a result, the connection area between the gas-sensitive portion 5 and the conductive film 6 is increased to improve the adhesion between the gas-sensitive portion 5 and the conductive film 6, and as a result, the electrode 3 and the gas-sensitive portion 5 are used. The adhesion between the two can be further improved. Further, the gas-sensitive portion connecting portions 61b and 62b having an area wider than the connection area of the electrode connecting portions 61a and 62a with the electrode 3 and having a larger area than the surface area of the electrode 3 are connected to the gas-sensitive portion 5 to be conductive. It is possible to more reliably secure the continuity between the film 6 and the gas-sensitive portion 5, and thus the continuity between the electrode 3 and the gas-sensitive portion 5, and it is possible to more reliably detect the change in the resistance value of the gas-sensitive portion 5. Further, it is possible to further suppress the change in the gas detection ability of the MEMS type semiconductor gas detection element 100 over time, and further suppress the deterioration of the gas detection sensitivity over time that occurs when exposed to a high temperature and high humidity environment, for example. Can be done. The gas-sensitive portion connecting portions 61b and 62b each have an area of approximately half that of the substrate 2 (main body portion 221) and are formed in a substantially semicircular shape. The gas-sensitive portion connecting portions 61b and 62b are linear portions of each substantially semicircle so as to face each other along a straight line S connecting the first end portion 3a and the second end portion 3b of the electrode 3. They are provided apart from each other via a gap G provided between them.

ＭＥＭＳ型半導体式ガス検知素子１００は、図４および図５に示されるように、電極３および導電膜６よりも電気抵抗が大きい絶縁膜８を備えている。絶縁膜８は、導電膜６が電極３の経路とは異なる（よりも短い）経路で電極３を電気的に短絡させないように、電極３の異なる２点間の隙間に形成される。より具体的には、絶縁膜８は、基板２（本体部２２１）上において電極３が設けられてない領域を充填するように設けられる。これにより、導電膜６による電極３の短絡をより確実に抑制することができるので、検知対象ガスに対してより高い感度を得ることができる。 As shown in FIGS. 4 and 5, the MEMS type semiconductor gas detection element 100 includes an insulating film 8 having a higher electric resistance than the electrode 3 and the conductive film 6. The insulating film 8 is formed in the gap between two different points of the electrode 3 so that the conductive film 6 does not electrically short-circuit the electrode 3 by a path different from (shorter than) the path of the electrode 3. More specifically, the insulating film 8 is provided on the substrate 2 (main body portion 221) so as to fill the region where the electrode 3 is not provided. As a result, the short circuit of the electrode 3 due to the conductive film 6 can be more reliably suppressed, so that higher sensitivity to the detection target gas can be obtained.

絶縁膜８は、電極３および導電膜６よりも電気抵抗が大きくなるように形成されていれば、その構成材料は特に限定されることはなく、たとえば酸化シリコン、窒化シリコン、酸化アルミニウム、酸化タンタルなどの絶縁性材料を主成分として構成することができる。本実施形態では、絶縁膜８は、基板２（本体部２２１）に含まれる絶縁性酸化物の金属元素または半導体元素と同一の金属元素または半導体元素を含む絶縁性酸化物を主成分として構成される。具体的には、たとえば基板２に含まれる絶縁性酸化物が酸化シリコンである場合、絶縁膜８は酸化シリコンを主成分として構成される。基板２に含まれる絶縁性酸化物の金属元素または半導体元素と同一の金属元素または半導体元素を含む絶縁性酸化物を主成分として絶縁膜８が構成されることにより、基板２と絶縁膜８とが互いに馴染みやすく、基板２と絶縁膜８との間の密着性を高めることができる。絶縁膜８の膜厚は、特に限定されることはなく、導電膜６が電極３の経路とは異なる経路で電極３を電気的に短絡させないように、また基板２との密着性を確保できるように適宜設定可能である。 As long as the insulating film 8 is formed so as to have a higher electric resistance than the electrode 3 and the conductive film 6, the constituent material thereof is not particularly limited, and for example, silicon oxide, silicon nitride, aluminum oxide, and tantalum oxide. It can be composed mainly of an insulating material such as. In the present embodiment, the insulating film 8 is mainly composed of an insulating oxide containing the same metal element or semiconductor element as the metal element or semiconductor element of the insulating oxide contained in the substrate 2 (main body 221). To. Specifically, for example, when the insulating oxide contained in the substrate 2 is silicon oxide, the insulating film 8 is composed mainly of silicon oxide. The substrate 2 and the insulating film 8 are formed by forming the insulating film 8 with the insulating oxide containing the same metal element or semiconductor element as the metal element or semiconductor element of the insulating oxide contained in the substrate 2 as a main component. Are easy to adapt to each other, and the adhesion between the substrate 2 and the insulating film 8 can be improved. The film thickness of the insulating film 8 is not particularly limited, and the conductive film 6 does not electrically short-circuit the electrode 3 in a path different from that of the electrode 3, and the adhesion to the substrate 2 can be ensured. Can be set as appropriate.

絶縁膜８は、電極３および導電膜６よりも電気抵抗が大きくなるように形成することができれば、その形成方法は特に限定されない。本実施形態では、絶縁膜８は、たとえばＣＶＤやスパッタリングなどの公知の成膜技術により形成することができる。絶縁膜８は、ＣＶＤやスパッタリングにより形成されることで、塗布などにより形成される場合と比べて、より緻密な膜として形成される。 The insulating film 8 is not particularly limited as long as it can be formed so that the electric resistance is larger than that of the electrode 3 and the conductive film 6. In the present embodiment, the insulating film 8 can be formed by a known film forming technique such as CVD or sputtering. Since the insulating film 8 is formed by CVD or sputtering, it is formed as a denser film as compared with the case where it is formed by coating or the like.

絶縁膜８は、上述したように、導電膜６が電極３の経路とは異なる経路で電極３を電気的に短絡させないように、電極３の異なる２点間の隙間に形成されていればよく、その配置は特に限定されない。絶縁膜８は、本実施形態では、図４および図５に示されるように、電極３間の隙間に設けられる電極間絶縁部８ａと、（本実施形態では、接着層９を介して）電極３の表面上に設けられる電極表面絶縁部８ｂとを備えている。電極間絶縁部８ａは、電極３間の隙間において、ガス感応部５側から基板２（本体部２２１）に向かって延びるように設けられている。電極間絶縁部８ａの一端は、基板２に接続され、電極間絶縁部８ａの他端は、電極表面絶縁部８ｂに接続される。基板２表面に沿う方向の電極間絶縁部８ａの側面は、隣接する電極３の側部に接続される。また、電極表面絶縁部８ｂは、基板２の表面に沿って面状に広がるように設けられる。電極表面絶縁部８ｂの一方の面は、ガス感応部５および導電膜６に接続され、電極表面絶縁部８ｂの他方の面は、（本実施形態では、接着層９を介して）電極３および電極間絶縁部８ａに接続される。電極表面絶縁部８ｂは、電極３の第１の端部領域３１および第２の端部領域３２に接続される導電膜６の電極接続部６１ａ、６２ａが貫通するための貫通孔が設けられている以外は、基板２の表面の略全体に亘って面状に広がるように設けられている。 As described above, the insulating film 8 may be formed in the gap between two different points of the electrode 3 so that the conductive film 6 does not electrically short-circuit the electrode 3 in a path different from that of the electrode 3. , The arrangement is not particularly limited. In the present embodiment, the insulating film 8 has an inter-electrode insulating portion 8a provided in the gap between the electrodes 3 and an electrode (via the adhesive layer 9 in the present embodiment) as shown in FIGS. 4 and 5. It is provided with an electrode surface insulating portion 8b provided on the surface of 3. The inter-electrode insulating portion 8a is provided so as to extend from the gas-sensitive portion 5 side toward the substrate 2 (main body portion 221) in the gap between the electrodes 3. One end of the inter-electrode insulating portion 8a is connected to the substrate 2, and the other end of the inter-electrode insulating portion 8a is connected to the electrode surface insulating portion 8b. The side surface of the inter-electrode insulating portion 8a in the direction along the surface of the substrate 2 is connected to the side portion of the adjacent electrode 3. Further, the electrode surface insulating portion 8b is provided so as to spread in a plane along the surface of the substrate 2. One surface of the electrode surface insulating portion 8b is connected to the gas sensitive portion 5 and the conductive film 6, and the other surface of the electrode surface insulating portion 8b is the electrode 3 and (in this embodiment, via the adhesive layer 9). It is connected to the inter-electrode insulating portion 8a. The electrode surface insulating portion 8b is provided with a through hole through which the electrode connecting portions 61a and 62a of the conductive film 6 connected to the first end region 31 and the second end region 32 of the electrode 3 penetrate. Except for the above, it is provided so as to spread in a plane shape over substantially the entire surface of the substrate 2.

以上に示したように、本実施形態では、図４および図５に示されるように、導電膜６および絶縁膜８は、（本実施形態では、一部において接着層９を介して）電極３を覆うように電極３に接続される。本実施形態では、電極３がヒータ４を兼ねているので、導電膜６および絶縁膜８はまた、ヒータ４を覆うようにヒータ４に接続される。ここで、導電膜６および絶縁膜８を、ガス感応部５よりも緻密であるように形成することで、ガス感応部５でヒータ４を覆う場合と比べて、ヒータ４の昇温時の劣化を抑制することができる。これは、ヒータ４の昇温時にマイグレーションなどの発生が抑制されるためだと考えられる。ヒータ４の熱耐久性を向上させることで、ＭＥＭＳ型半導体式ガス検知素子１００の長期使用が可能になる。 As shown above, in the present embodiment, as shown in FIGS. 4 and 5, the conductive film 6 and the insulating film 8 are the electrodes 3 (partly via the adhesive layer 9 in the present embodiment). It is connected to the electrode 3 so as to cover the above. In the present embodiment, since the electrode 3 also serves as the heater 4, the conductive film 6 and the insulating film 8 are also connected to the heater 4 so as to cover the heater 4. Here, by forming the conductive film 6 and the insulating film 8 so as to be denser than the gas-sensitive portion 5, deterioration of the heater 4 at the time of temperature rise is compared with the case where the heater 4 is covered with the gas-sensitive portion 5. Can be suppressed. It is considered that this is because the occurrence of migration and the like is suppressed when the temperature of the heater 4 is raised. By improving the thermal durability of the heater 4, the MEMS type semiconductor gas detection element 100 can be used for a long period of time.

以下において、実施例をもとに２つの実施形態のＭＥＭＳ型半導体式ガス検知素子の優れた効果を説明する。ただし、本発明のＭＥＭＳ型半導体式ガス検知素子は、以下の実施例に限定されるものではない。 Hereinafter, the excellent effects of the MEMS type semiconductor gas detection elements of the two embodiments will be described based on the embodiments. However, the MEMS type semiconductor gas detection element of the present invention is not limited to the following examples.

（実施例１）
図１および図２に示されるＭＥＭＳ型半導体式ガス検知素子１を以下の手順で作製した。まず、公知の微細加工技術により、基板２を作成し、基板２上に導電膜６／電極３（ヒータ４）／接着層９を配線した。その際、接着層９としては、酸化タンタルを用い、電極３（ヒータ４）としては、白金を用い、導電膜６としては酸化スズを用いた。接着層９、電極３（ヒータ４）および導電膜６はそれぞれ、スパッタリングにより形成した。接着層９、電極３（ヒータ４）および導電膜６の膜厚はそれぞれ、２０ｎｍ、３００ｎｍおよび１００ｎｍとした。つぎに、アンチモンをドナーとして０．１ｗｔ％添加した酸化スズ半導体の微粉体のペーストを、基板２上の接着層９／電極３（ヒータ４）／導電膜６を覆って最大厚さが２０μｍになるように塗布して、乾燥後、電気炉にて６５０℃で２時間加熱して焼結することにより、ガス感応部５を形成した。引き続いて、ガス感応部５を被覆するように機能層７を設けた。機能層７は、酸化パラジウムの微粉体を混ぜたアルミナの微粉体のペーストを、ガス感応部５を覆って最大厚さが３０μｍになるように塗布して、乾燥後、電気炉にて６５０℃で２時間加熱して焼結することにより形成した。以上のＭＥＭＳ型半導体式ガス検知素子を、後述する検出感度試験に供した。 (Example 1)
The MEMS type semiconductor gas detection element 1 shown in FIGS. 1 and 2 was manufactured by the following procedure. First, the substrate 2 was prepared by a known microfabrication technique, and the conductive film 6 / electrode 3 (heater 4) / adhesive layer 9 was wired on the substrate 2. At that time, tantalum pentoxide was used as the adhesive layer 9, platinum was used as the electrode 3 (heater 4), and tin oxide was used as the conductive film 6. The adhesive layer 9, the electrode 3 (heater 4), and the conductive film 6 were each formed by sputtering. The film thicknesses of the adhesive layer 9, the electrode 3 (heater 4) and the conductive film 6 were set to 20 nm, 300 nm and 100 nm, respectively. Next, a paste of fine powder of tin oxide semiconductor to which 0.1 wt% of antimony was added as a donor covers the adhesive layer 9 / electrode 3 (heater 4) / conductive film 6 on the substrate 2 to a maximum thickness of 20 μm. The gas-sensitive portion 5 was formed by applying the mixture in such a manner, drying the mixture, heating the mixture in an electric furnace at 650 ° C. for 2 hours, and sintering the mixture. Subsequently, the functional layer 7 was provided so as to cover the gas-sensitive portion 5. The functional layer 7 is coated with a paste of alumina fine powder mixed with palladium oxide fine powder so as to cover the gas-sensitive portion 5 so as to have a maximum thickness of 30 μm, and after drying, the temperature is 650 ° C. in an electric furnace. It was formed by heating in 2 hours and sintering. The above-mentioned MEMS type semiconductor gas detection element was subjected to a detection sensitivity test described later.

（実施例２）
図４および図５に示されるＭＥＭＳ型半導体式ガス検知素子１００の電極３（ヒータ４）の熱耐久性を評価しやすくするために、ＭＥＭＳ型半導体式ガス検知素子１００からガス感応部５および機能層７を除いたサンプルを以下の手順で作製した。まず、公知の微細加工技術により、基板２を作成し、基板２上に接着層９／電極３（ヒータ４）／接着層９を配線した。その際、接着層９としては、酸化タンタルを用い、電極３（ヒータ４）としては、白金を用いた。接着層９および電極３（ヒータ４）はそれぞれ、スパッタリングにより形成した。接着層９および電極３（ヒータ４）の膜厚はそれぞれ、２０ｎｍおよび３００ｎｍとした。つぎに、公知の微細加工技術により、導電膜６／絶縁膜８を接着層９／電極３（ヒータ４）／接着層９上に配置した。導電膜６としては、酸化スズを用い、絶縁膜８としては、酸化シリコンを用いた。導電膜６は、スパッタリングにより形成し、絶縁膜８は、ＣＶＤにより形成した。導電膜６および絶縁膜８の膜厚はそれぞれ、５００ｎｍおよび１０００ｎｍとした。以上のサンプルを、後述する熱耐久性試験に供した。 (Example 2)
In order to facilitate the evaluation of the thermal durability of the electrode 3 (heater 4) of the MEMS type semiconductor gas detection element 100 shown in FIGS. 4 and 5, the gas sensitive unit 5 and the function from the MEMS type semiconductor gas detection element 100 A sample excluding the layer 7 was prepared by the following procedure. First, the substrate 2 was prepared by a known microfabrication technique, and the adhesive layer 9 / electrode 3 (heater 4) / adhesive layer 9 was wired on the substrate 2. At that time, tantalum pentoxide was used as the adhesive layer 9, and platinum was used as the electrode 3 (heater 4). The adhesive layer 9 and the electrode 3 (heater 4) were each formed by sputtering. The film thicknesses of the adhesive layer 9 and the electrode 3 (heater 4) were set to 20 nm and 300 nm, respectively. Next, the conductive film 6 / insulating film 8 was placed on the adhesive layer 9 / electrode 3 (heater 4) / adhesive layer 9 by a known microfabrication technique. Tin oxide was used as the conductive film 6, and silicon oxide was used as the insulating film 8. The conductive film 6 was formed by sputtering, and the insulating film 8 was formed by CVD. The film thicknesses of the conductive film 6 and the insulating film 8 were set to 500 nm and 1000 nm, respectively. The above samples were subjected to a thermal durability test described later.

（実施例３）
実施例２のサンプルに以下の手順でガス感応部５および機能層７を設けることで、図４および図５に示されるＭＥＭＳ型半導体式ガス検知素子１００を作製した。アンチモンをドナーとして０．１ｗｔ％添加した酸化スズ半導体の微粉体のペーストを、実施例２のサンプルの導電膜６／絶縁膜８を覆って最大厚さが２０μｍになるように塗布して、乾燥後、電気炉にて６５０℃で２時間加熱して焼結することにより、ガス感応部５を形成した。引き続いて、ガス感応部５を被覆するように機能層７を設けた。機能層７は、酸化パラジウムの微粉体を混ぜたアルミナの微粉体のペーストを、ガス感応部５を覆って最大厚さが３０μｍになるように塗布して、乾燥後、電気炉にて６５０℃で２時間加熱して焼結することにより形成した。以上のＭＥＭＳ型半導体式ガス検知素子を、後述する検出感度試験および高温高湿耐久性試験に供した。 (Example 3)
By providing the gas sensitive portion 5 and the functional layer 7 in the sample of Example 2 by the following procedure, the MEMS type semiconductor gas detection element 100 shown in FIGS. 4 and 5 was manufactured. A paste of fine powder of tin oxide semiconductor to which 0.1 wt% of antimony was added as a donor was applied over the conductive film 6 / insulating film 8 of the sample of Example 2 so as to have a maximum thickness of 20 μm, and dried. After that, the gas-sensitive portion 5 was formed by heating in an electric furnace at 650 ° C. for 2 hours and sintering the mixture. Subsequently, the functional layer 7 was provided so as to cover the gas-sensitive portion 5. The functional layer 7 is coated with a paste of alumina fine powder mixed with palladium oxide fine powder so as to cover the gas-sensitive portion 5 so as to have a maximum thickness of 30 μm, and after drying, the temperature is 650 ° C. in an electric furnace. It was formed by heating in 2 hours and sintering. The above-mentioned MEMS type semiconductor gas detection element was subjected to a detection sensitivity test and a high-temperature and high-humidity durability test, which will be described later.

（比較例１）
熱耐久性評価の比較例として、図１および図２に示されるＭＥＭＳ型半導体式ガス検知素子１から導電膜６、ガス感応部５および機能層７を除いたサンプルを以下の手順で作製した。まず、公知の微細加工技術により、基板２を作成し、基板２上に電極３（ヒータ４）／接着層９を配線した。その際、接着層９としては、酸化タンタルを用い、電極３（ヒータ４）としては、白金を用いた。接着層９および電極３（ヒータ４）はそれぞれ、スパッタリングにより形成した。接着層９および電極３（ヒータ４）の膜厚はそれぞれ、２０ｎｍおよび３００ｎｍとした。以上のサンプルを、後述する熱耐久性試験に供した。 (Comparative Example 1)
As a comparative example of thermal durability evaluation, a sample obtained by removing the conductive film 6, the gas sensitive portion 5 and the functional layer 7 from the MEMS type semiconductor gas detection element 1 shown in FIGS. 1 and 2 was prepared by the following procedure. First, the substrate 2 was prepared by a known microfabrication technique, and the electrode 3 (heater 4) / adhesive layer 9 was wired on the substrate 2. At that time, tantalum pentoxide was used as the adhesive layer 9, and platinum was used as the electrode 3 (heater 4). The adhesive layer 9 and the electrode 3 (heater 4) were each formed by sputtering. The film thicknesses of the adhesive layer 9 and the electrode 3 (heater 4) were set to 20 nm and 300 nm, respectively. The above samples were subjected to a thermal durability test described later.

（比較例２）
比較例１のサンプルに以下の手順でガス感応部５および機能層７を設けることで、図１および図２に示されるＭＥＭＳ型半導体式ガス検知素子１から導電膜６を除いたＭＥＭＳ型半導体式ガス検知素子を作製した。アンチモンをドナーとして０．１ｗｔ％添加した酸化スズ半導体の微粉体のペーストを、比較例１のサンプルの電極３（ヒータ４）／接着層９を覆って最大厚さが２０μｍになるように塗布して、乾燥後、電気炉にて６５０℃で２時間加熱して焼結することにより、ガス感応部５を形成した。引き続いて、ガス感応部５を被覆するように機能層７を設けた。機能層７は、酸化パラジウムの微粉体を混ぜたアルミナの微粉体のペーストを、ガス感応部５を覆って最大厚さが３０μｍになるように塗布して、乾燥後、電気炉にて６５０℃で２時間加熱して焼結することにより形成した。以上のＭＥＭＳ型半導体式ガス検知素子を、後述する検出感度試験および高温高湿耐久性試験に供した。 (Comparative Example 2)
By providing the gas sensitive portion 5 and the functional layer 7 in the sample of Comparative Example 1 by the following procedure, the MEMS type semiconductor type semiconductor type in which the conductive film 6 is removed from the MEMS type semiconductor type gas detection element 1 shown in FIGS. 1 and 2 is obtained. A gas detection element was manufactured. A paste of fine powder of tin oxide semiconductor to which 0.1 wt% of antimony was added as a donor was applied over the electrode 3 (heater 4) / adhesive layer 9 of the sample of Comparative Example 1 so as to have a maximum thickness of 20 μm. After drying, the gas-sensitive portion 5 was formed by heating in an electric furnace at 650 ° C. for 2 hours and sintering the mixture. Subsequently, the functional layer 7 was provided so as to cover the gas-sensitive portion 5. The functional layer 7 is coated with a paste of alumina fine powder mixed with palladium oxide fine powder so as to cover the gas-sensitive portion 5 so as to have a maximum thickness of 30 μm, and after drying, the temperature is 650 ° C. in an electric furnace. It was formed by heating in 2 hours and sintering. The above-mentioned MEMS type semiconductor gas detection element was subjected to a detection sensitivity test and a high-temperature and high-humidity durability test, which will be described later.

（検出感度試験）
実施例１、３および比較例２のＭＥＭＳ型半導体式ガス検知素子を、公知のブリッジ回路に組み込んで、検知対象ガスを含む大気環境下でセンサ出力を測定した。検知対象ガスとしては、メタン、エタノール、水素を用いた。 (Detection sensitivity test)
The MEMS type semiconductor gas detection elements of Examples 1 and 3 and Comparative Example 2 were incorporated into a known bridge circuit, and the sensor output was measured in an atmospheric environment containing a gas to be detected. Methane, ethanol, and hydrogen were used as the detection target gas.

（高温高湿耐久性試験）
実施例３および比較例２のＭＥＭＳ型半導体式ガス検知素子を、公知のガス検知器に組み込んで、２０℃、６０％ＲＨの標準環境および４０℃、８５％ＲＨの高温高湿環境のそれぞれで放置した後に、メタンに対して所定のセンサ出力に達した際に警報を発するように設定されたガス検知器が警報を発するメタンの濃度を測定した。 (High temperature and high humidity durability test)
The MEMS type semiconductor gas detectors of Example 3 and Comparative Example 2 were incorporated into a known gas detector in a standard environment of 20 ° C. and 60% RH and a high temperature and high humidity environment of 40 ° C. and 85% RH, respectively. After being left unattended, a gas detector set to issue an alarm when a predetermined sensor output was reached for methane measured the concentration of methane that issued an alarm.

（熱耐久性試験）
実施例２および比較例１のサンプルの電極３（ヒータ４）に所定の電力を投入して、電極３（ヒータ４）が断線するまでの時間（断線寿命）を測定した。 (Thermal durability test)
A predetermined electric power was applied to the electrode 3 (heater 4) of the samples of Example 2 and Comparative Example 1, and the time until the electrode 3 (heater 4) was disconnected (the disconnection life) was measured.

（検出感度試験結果）
実施例１、３および比較例２のＭＥＭＳ型半導体式ガス検知素子について、メタン、エタノール、水素の濃度を変化させたときのセンサ出力の変化を調べた結果を図７および図８に示す。 (Detection sensitivity test result)
7 and 8 show the results of investigating changes in the sensor output of the MEMS type semiconductor gas detection elements of Examples 1 and 3 and Comparative Example 2 when the concentrations of methane, ethanol, and hydrogen were changed.

図８の比較例２の検出感度試験結果では、メタン、エタノール、水素のそれぞれの濃度の増加に伴ってそれぞれのセンサ出力が増加している。それに対して、図７（ａ）の実施例１の検出感度試験結果では、図８の比較例２の結果と比べて、いずれのガス濃度でもセンサ出力が増加している。これは、電極３と比較してガス感応部５に対する密着性が高い導電膜６を介して電極３とガス感応部５とが接続されることで、電極３に対するガス感応部５の密着性が高まり、電極３とガス感応部５との間に良好な電気接続が確保されたためだと考えられる。このように、検知対象ガスに対するガス感応部５の検知感度を向上させることで、検知対象ガスがガス感応部５に接触した際に生じるガス感応部５の抵抗値の変化をより正確に検知し、検知対象ガスをより正確に検知することができる。さらに、図７（ｂ）の実施例３の検出感度試験結果では、図８の比較例２の結果と比べて、図７（ａ）の実施例１の結果よりも、いずれのガス濃度でもセンサ出力が増加している。これは、実施例１よりもガス感応部５と導電膜６との間の接続面積が大きくなって、ガス感応部５と導電膜６との間の密着力がさらに向上し、結果として、電極３とガス感応部５との間の密着性がさらに向上し、電極３とガス感応部５との間にさらに良好な電気接続を確保することができたためだと考えられる。このように、検知対象ガスに対するガス感応部５の検知感度をさらに向上させることで、検知対象ガスがガス感応部５に接触した際に生じるガス感応部５の抵抗値の変化をより正確に検知し、検知対象ガスをより正確に検知することができる。 In the detection sensitivity test result of Comparative Example 2 in FIG. 8, the sensor output of each of them increases as the concentrations of methane, ethanol, and hydrogen increase. On the other hand, in the detection sensitivity test result of Example 1 of FIG. 7A, the sensor output is increased at any gas concentration as compared with the result of Comparative Example 2 of FIG. This is because the electrode 3 and the gas-sensitive portion 5 are connected to each other via the conductive film 6 which has higher adhesion to the gas-sensitive portion 5 than the electrode 3, so that the adhesion of the gas-sensitive portion 5 to the electrode 3 is improved. It is considered that this is because a good electrical connection was secured between the electrode 3 and the gas sensitive portion 5. In this way, by improving the detection sensitivity of the gas sensitive unit 5 with respect to the detection target gas, the change in the resistance value of the gas sensitive unit 5 that occurs when the detection target gas comes into contact with the gas sensitive unit 5 is detected more accurately. , The detection target gas can be detected more accurately. Further, in the detection sensitivity test result of Example 3 of FIG. 7 (b), the sensor at any gas concentration is higher than the result of Example 1 of FIG. 7 (a) as compared with the result of Comparative Example 2 of FIG. The output is increasing. This is because the connection area between the gas-sensitive portion 5 and the conductive film 6 is larger than that in the first embodiment, and the adhesion between the gas-sensitive portion 5 and the conductive film 6 is further improved, and as a result, the electrode It is considered that this is because the adhesion between 3 and the gas sensitive portion 5 is further improved, and a better electrical connection can be secured between the electrode 3 and the gas sensitive portion 5. In this way, by further improving the detection sensitivity of the gas sensitive unit 5 with respect to the detection target gas, the change in the resistance value of the gas sensitive unit 5 that occurs when the detection target gas comes into contact with the gas sensitive unit 5 is detected more accurately. However, the gas to be detected can be detected more accurately.

（高温高湿耐久性試験）
公知のガス検知器に組み込まれた実施例３および比較例２のＭＥＭＳ型半導体式ガス検知素子について、２０℃、６０％ＲＨの標準環境および４０℃、８５％ＲＨの高温高湿環境のそれぞれに放置したときの、ガス検知器が警報を発するメタンの濃度の経時変化を調べた結果を図９および図１０に示す。ガス検知器は、所定のセンサ出力が得られたときに警報を発するように設定されているので、ガス検知器が警報を発するメタンの濃度の経時変化は、ＭＥＭＳ型半導体式ガス検知素子のメタンに対する検知感度の経時変化を表している。たとえば、ガス検知器が警報を発するメタンの濃度が高ければ高いほど、ＭＥＭＳ型半導体式ガス検知素子のメタンに対する検知感度が低いことを示している。 (High temperature and high humidity durability test)
The MEMS type semiconductor gas detection elements of Example 3 and Comparative Example 2 incorporated in a known gas detector were subjected to a standard environment of 20 ° C. and 60% RH and a high temperature and high humidity environment of 40 ° C. and 85% RH, respectively. 9 and 10 show the results of investigating the change over time in the concentration of methane that the gas detector issues an alarm when left unattended. Since the gas detector is set to issue an alarm when a predetermined sensor output is obtained, the change in the concentration of methane that the gas detector issues an alarm over time is the methane of the MEMS type semiconductor type gas detection element. It shows the change over time in the detection sensitivity. For example, the higher the concentration of methane in which the gas detector issues an alarm, the lower the detection sensitivity of the MEMS type semiconductor gas detection element to methane.

２０℃、６０％ＲＨの標準環境に実施例３および比較例２のＭＥＭＳ型半導体式ガス検知素子を放置した結果（図９）では、実施例３（図９（ａ））および比較例２（図９（ｂ））ともに、経過日数の増加に伴って、わずかにメタン濃度が低下する（メタン検知感度が増加する）傾向が見られるものの、メタン濃度（メタン検知感度）は概してほぼ一定である。それに対して、４０℃、８５％ＲＨの高温高湿環境に実施例３および比較例２のＭＥＭＳ型半導体式ガス検知素子を放置した結果（図１０）では、比較例２（図１０（ｂ））において、経過日数の増加に伴って、メタン濃度が大幅に増加している（メタン検知感度が大幅に低下している）のに対して、実施例３（図１０（ａ））において、メタン濃度の増加（メタン検知感度の低下）が抑制されている。つまり、実施例３では、高温高湿環境下に曝された場合に生じる経時的なガス検知感度の劣化が抑制されている。これは、電極３と比較してガス感応部５に対する密着性が高い導電膜６を介して電極３とガス感応部５とが接続されることで、電極３に対するガス感応部５の密着性が高まり、電極３とガス感応部５との間に良好な電気接続が確保されたためだと考えられる。 As a result of leaving the MEMS type semiconductor gas detection element of Example 3 and Comparative Example 2 in a standard environment at 20 ° C. and 60% RH (FIG. 9), Example 3 (FIG. 9 (a)) and Comparative Example 2 ( In both FIGS. 9 (b) and 9 (b), the methane concentration (methane detection sensitivity) is generally almost constant, although the methane concentration tends to decrease slightly (the methane detection sensitivity increases) as the number of elapsed days increases. .. On the other hand, in the result of leaving the MEMS type semiconductor gas detection element of Example 3 and Comparative Example 2 in a high temperature and high humidity environment of 40 ° C. and 85% RH (FIG. 10), Comparative Example 2 (FIG. 10 (b)). ), The methane concentration is significantly increased (the methane detection sensitivity is significantly reduced) with the increase in the number of elapsed days, whereas in Example 3 (FIG. 10 (a)), methane is used. The increase in concentration (decrease in methane detection sensitivity) is suppressed. That is, in Example 3, the deterioration of the gas detection sensitivity over time that occurs when exposed to a high temperature and high humidity environment is suppressed. This is because the electrode 3 and the gas-sensitive portion 5 are connected to each other via the conductive film 6 which has higher adhesion to the gas-sensitive portion 5 than the electrode 3, so that the adhesion of the gas-sensitive portion 5 to the electrode 3 is improved. It is considered that this is because a good electrical connection was secured between the electrode 3 and the gas sensitive portion 5.

（熱耐久性試験結果）
実施例２および比較例１のサンプルの電極３（ヒータ４）に所定の電力を投入して、電極３（ヒータ４）が断線するまでの時間（断線寿命）を測定した結果を図１１に示す。図１１では、実施例２および比較例１ともに、投入電力の増加に伴って断線寿命が短くなっているが、比較例１と比べて実施例２の方が、断線寿命が大幅に長くなっている。これは、緻密な導電膜６および絶縁膜８がヒータ４を覆うようにヒータ４に接続されたことで、ヒータ４の昇温時にマイグレーションなどの発生が抑制されたためだと考えられる。このように、緻密な導電膜６および絶縁膜８がヒータ４を覆うようにヒータ４に接続して、ヒータ４の熱耐久性を向上させることで、ＭＥＭＳ型半導体式ガス検知素子１００の長期使用が可能になる。 (Thermal durability test result)
FIG. 11 shows the results of measuring the time (wire disconnection life) until the electrode 3 (heater 4) is disconnected by applying a predetermined power to the electrode 3 (heater 4) of the samples of Example 2 and Comparative Example 1. .. In FIG. 11, in both Example 2 and Comparative Example 1, the disconnection life is shortened as the input power is increased, but the disconnection life is significantly longer in Example 2 than in Comparative Example 1. There is. It is considered that this is because the dense conductive film 6 and the insulating film 8 are connected to the heater 4 so as to cover the heater 4, so that the occurrence of migration and the like is suppressed when the temperature of the heater 4 is raised. In this way, the dense conductive film 6 and the insulating film 8 are connected to the heater 4 so as to cover the heater 4, and the thermal durability of the heater 4 is improved, so that the MEMS type semiconductor gas detection element 100 can be used for a long period of time. Will be possible.

１、１００ ＭＥＭＳ型半導体式ガス検知素子
２ 基板
２１ 基板本体
２１ａ 凹部
２２ 絶縁支持膜
２２ａ 酸化シリコン膜
２２ｂ 窒化シリコン膜
２２ｃ 酸化シリコン膜
２２１ 本体部
２２１ａ 第１の領域
２２１ｂ 第２の領域
２２２ 基部
２２３ 接続部
２３ 空洞部
３ 電極
３ａ 第１の端部
３ｂ 第２の端部
３ｃ 第１の近接部
３ｄ 第２の近接部
３１ 第１の端部領域
３２ 第２の端部領域
３３ 本体領域
３３１ 第１の本体領域
３３２ 第２の本体領域
３３３ 中間領域
４ ヒータ
５ ガス感応部
６ 導電膜
６１ 第１の導電膜
６１ａ 電極接続部
６１ｂ ガス感応部接続部
６２ 第２の導電膜
６２ａ 電極接続部
６２ｂ ガス感応部接続部
７ 機能層
８ 絶縁膜
８ａ 電極間絶縁部
８ｂ 電極表面絶縁部
９ 接着層
Ａ 集積部
Ｇ ギャップ
Ｌ１ 一方のリード線
Ｌ２ 他方のリード線
Ｓ 第１の端部と第２の端部とを結ぶ直線 1,100 MEMS type semiconductor gas detection element 2 board 21 board body 21a recess 22 insulation support film 22a silicon oxide film 22b silicon nitride film 22c silicon oxide film 221 body part 221a first area 221b second area 222 base part 223 connection Part 23 Cavity part 3 Electrode 3a First end part 3b Second end part 3c First proximity part 3d Second proximity part 31 First end area 32 Second end area 33 Main body area 331 First Main body area 332 Second main body area 333 Intermediate area 4 Heater 5 Gas sensitive part 6 Conductive body 61 First conductive film 61a Electrode connection part 61b Gas sensitive part Connection part 62 Second conductive film 62a Electrode connection part 62b Gas sensitive part Connection part 7 Functional layer 8 Insulation film 8a Insulation part between electrodes 8b Electrode surface insulation part 9 Adhesive layer A Integration part G Gap L1 One lead wire L2 Another lead wire S First end and second end Straight line connecting

Claims (6)

基板と、
前記基板に設けられる電極と、
前記基板に設けられるヒータと、
前記電極に電気的に接続し、前記ヒータに熱的に接続するように前記基板に設けられるガス感応部と
を備えるＭＥＭＳ型半導体式ガス検知素子であって、
前記電極と比較して前記ガス感応部に対する密着性が高く、前記電極と前記ガス感応部とを接続する導電膜を備え、
前記導電膜は、前記電極の経路とは異なる経路で前記電極を電気的に短絡させないように、前記電極の少なくとも一部の上面に接続される、
ＭＥＭＳ型半導体式ガス検知素子。 With the board
The electrodes provided on the substrate and
The heater provided on the substrate and
A MEMS-type semiconductor gas detection element provided with a gas-sensitive portion provided on the substrate so as to be electrically connected to the electrode and thermally connected to the heater.
It has a higher adhesion to the gas-sensitive portion than the electrode, and is provided with a conductive film connecting the electrode and the gas-sensitive portion.
The conductive film is connected to the upper surface of at least a part of the electrode so as not to electrically short-circuit the electrode by a path different from that of the electrode.
MEMS type semiconductor gas detection element. 前記導電膜は、前記ガス感応部に含まれる金属酸化物半導体の金属元素と同一の金属元素を含む金属酸化物半導体を主成分として形成される、
請求項１に記載のＭＥＭＳ型半導体式ガス検知素子。 The conductive film is formed mainly of a metal oxide semiconductor containing the same metal element as the metal element of the metal oxide semiconductor contained in the gas sensitive portion.
The MEMS type semiconductor gas detection element according to claim 1. 前記ＭＥＭＳ型半導体式ガス検知素子が、前記電極および前記導電膜よりも電気抵抗が大きい絶縁膜を備え、
前記絶縁膜は、前記導電膜が前記電極の経路とは異なる（よりも短い）経路で前記電極を電気的に短絡させないように、前記電極の異なる２点間の隙間に形成される、
請求項１または２に記載のＭＥＭＳ型半導体式ガス検知素子。 The MEMS type semiconductor gas detection element includes the electrode and an insulating film having a higher electric resistance than the conductive film.
The insulating film is formed in a gap between two different points of the electrode so that the conductive film does not electrically short-circuit the electrode by a path different from (shorter than) the path of the electrode.
The MEMS type semiconductor gas detection element according to claim 1 or 2. 前記導電膜の少なくとも一部が、前記絶縁膜の上に設けられる、
請求項３に記載のＭＥＭＳ型半導体式ガス検知素子。 At least a part of the conductive film is provided on the insulating film.
The MEMS type semiconductor gas detection element according to claim 3. 前記電極が、一方のリード線に接続される第１の端部を含む第１の端部領域と、他方のリード線に接続される第２の端部を含む第２の端部領域と、前記第１の端部領域と前記第２の端部領域との間に延び、前記第１の端部領域と前記第２の端部領域とを接続する本体領域とを備え、
前記導電膜は、前記第１の端部領域および前記第２の端部領域に接続される、
請求項１～４のいずれか１項に記載のＭＥＭＳ型半導体式ガス検知素子。 A first end region containing a first end of the electrode connected to one lead and a second end region containing a second end of the electrode connected to the other lead. It comprises a body region that extends between the first end region and the second end region and connects the first end region and the second end region.
The conductive film is connected to the first end region and the second end region.
The MEMS type semiconductor gas detection element according to any one of claims 1 to 4. 前記電極は、前記ヒータを兼ねており、
前記導電膜および前記絶縁膜は、前記ガス感応部よりも緻密であり、
前記導電膜および前記絶縁膜は、前記ヒータを覆うように前記ヒータに接続される、
請求項１～５のいずれか１項に記載のＭＥＭＳ型半導体式ガス検知素子。 The electrode also serves as the heater.
The conductive film and the insulating film are denser than the gas-sensitive portion.
The conductive film and the insulating film are connected to the heater so as to cover the heater.
The MEMS type semiconductor gas detection element according to any one of claims 1 to 5.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006528766A (en) * 2003-07-25 2006-12-21 パラゴン アクチエンゲゼルシャフト Gas sensor and method for manufacturing a gas sensor
JP2007057254A (en) * 2005-08-22 2007-03-08 Fuji Electric Fa Components & Systems Co Ltd Thin-film gas sensor and its manufacturing method
JP2010091501A (en) * 2008-10-10 2010-04-22 Ngk Spark Plug Co Ltd Gas sensor
JP6679789B1 (en) * 2019-03-29 2020-04-15 新コスモス電機株式会社 MEMS type semiconductor gas detector

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006528766A (en) * 2003-07-25 2006-12-21 パラゴン アクチエンゲゼルシャフト Gas sensor and method for manufacturing a gas sensor
JP2007057254A (en) * 2005-08-22 2007-03-08 Fuji Electric Fa Components & Systems Co Ltd Thin-film gas sensor and its manufacturing method
JP2010091501A (en) * 2008-10-10 2010-04-22 Ngk Spark Plug Co Ltd Gas sensor
JP6679789B1 (en) * 2019-03-29 2020-04-15 新コスモス電機株式会社 MEMS type semiconductor gas detector

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