JPH0650919A - Gas sensor - Google Patents
Gas sensorInfo
- Publication number
- JPH0650919A JPH0650919A JP22486292A JP22486292A JPH0650919A JP H0650919 A JPH0650919 A JP H0650919A JP 22486292 A JP22486292 A JP 22486292A JP 22486292 A JP22486292 A JP 22486292A JP H0650919 A JPH0650919 A JP H0650919A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- film
- thickness
- metal oxide
- oxide semiconductor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000010408 film Substances 0.000 claims abstract description 33
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 22
- 239000010409 thin film Substances 0.000 claims abstract description 18
- 239000004065 semiconductor Substances 0.000 claims abstract description 13
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 12
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 12
- 235000012239 silicon dioxide Nutrition 0.000 claims abstract description 11
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 11
- 239000000758 substrate Substances 0.000 claims abstract description 9
- 238000000034 method Methods 0.000 abstract description 8
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 abstract description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 abstract description 3
- 239000010931 gold Substances 0.000 abstract description 3
- 229910052737 gold Inorganic materials 0.000 abstract description 3
- 238000010030 laminating Methods 0.000 abstract description 2
- 238000007639 printing Methods 0.000 abstract description 2
- 230000035945 sensitivity Effects 0.000 abstract description 2
- 238000004544 sputter deposition Methods 0.000 abstract description 2
- 229910017083 AlN Inorganic materials 0.000 abstract 1
- PIGFYZPCRLYGLF-UHFFFAOYSA-N Aluminum nitride Chemical compound [Al]#N PIGFYZPCRLYGLF-UHFFFAOYSA-N 0.000 abstract 1
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 238000001771 vacuum deposition Methods 0.000 abstract 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 229910001887 tin oxide Inorganic materials 0.000 description 3
- 229910006404 SnO 2 Inorganic materials 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 210000001520 comb Anatomy 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 238000007733 ion plating Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 125000002524 organometallic group Chemical group 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ガスセンサに関する。
更に詳しくは、ガス感応性膜として金属酸化物半導体薄
膜を形成させたガスセンサに関する。FIELD OF THE INVENTION The present invention relates to a gas sensor.
More specifically, it relates to a gas sensor having a metal oxide semiconductor thin film formed as a gas sensitive film.
【０００２】[0002]
【従来の技術】従来から、ガスセンサのガス感応性膜と
して酸化錫膜、酸化亜鉛膜などの金属酸化物半導体の焼
結体物が実際に用いられている。これらのガス感応性膜
にあっては、そこにＶ，Ｆなどの種々の添加物を加え
て、センサ特性の湿度依存性を抑制することが行われて
いる。しかしながら、この方法ではガス感応性膜と水蒸
気との間の接触状態に変化がみられないので、耐湿性を
向上させることとは無関係である。2. Description of the Related Art Conventionally, a sintered body of a metal oxide semiconductor such as a tin oxide film and a zinc oxide film has been actually used as a gas sensitive film of a gas sensor. In these gas-sensitive membranes, various additives such as V and F are added to suppress the humidity dependence of sensor characteristics. However, this method does not show any change in the contact state between the gas-sensitive film and the water vapor, and is therefore irrelevant to improving the moisture resistance.
【０００３】一方、ガス感応性膜と水蒸気との間の接触
度合を低下させる目的で、ガスセンサへ導かれる被測定
ガス用のフィルタとこのフィルタの熱を下げる除熱手段
を設け、被測定ガスをフィルタにおいて冷却し、水分を
結露させた後ガスセンサに導くことも提案されているが
(特開昭63-233,359号公報)、この方法ではわざわざフィ
ルタの除熱手段を必要としている。On the other hand, for the purpose of reducing the degree of contact between the gas-sensitive film and water vapor, a filter for the gas to be measured introduced to the gas sensor and heat removal means for lowering the heat of the filter are provided to measure the gas to be measured. It is also proposed to cool the water in a filter and allow water to condense before being led to a gas sensor.
(Japanese Patent Laid-Open No. 63-233,359), this method requires a means for removing heat from the filter.
【０００４】[0004]
【発明が解決しようとする課題】本発明の目的は、ガス
感応性膜として金属酸化物半導体薄膜を形成させたガス
センサにおいて、それの耐湿性を向上させることにあ
る。SUMMARY OF THE INVENTION An object of the present invention is to improve the humidity resistance of a gas sensor having a metal oxide semiconductor thin film formed as a gas sensitive film.
【０００５】[0005]
【課題を解決するための手段】かかる本発明の目的は、
絶縁性基板上に形成させた一組の電極を覆う金属酸化物
半導体薄膜上に、二酸化けい素膜を積層し被覆したガス
センサによって達成される。The object of the present invention is as follows.
It is achieved by a gas sensor in which a silicon dioxide film is laminated and coated on a metal oxide semiconductor thin film covering a set of electrodes formed on an insulating substrate.
【０００６】絶縁性基板としては、アルミナ、窒化アル
ミニウムなどが用いられ、これらの基板上には、例えば
金ペーストの厚膜を所定形状に印刷するなどの方法で一
組の電極、一般には対向くし形電極が形成される。Alumina, aluminum nitride or the like is used as the insulating substrate, and a pair of electrodes, generally facing combs, is formed on these substrates by, for example, printing a thick film of gold paste in a predetermined shape. Shaped electrodes are formed.
【０００７】一組の電極を覆う金属酸化物半導体薄膜と
しては、膜厚が約150〜500nmのSnO2などが用いられる。
半導体薄膜の形成は、真空蒸着法、スパッタリング法、
イオンプレーティング法などによりSnO2膜などを直接形
成させる方法、金属Sn膜などを形成させた後、熱処理し
て酸化する方法あるいはSnを含む有機金属モノマーをプ
ラズマ重合させてプラズマ重合膜を形成させ、これを熱
処理する方法(特開昭63-261,148号公報)などによって行
われる。As the metal oxide semiconductor thin film covering the set of electrodes, SnO 2 or the like having a film thickness of about 150 to 500 nm is used.
The semiconductor thin film is formed by vacuum vapor deposition, sputtering,
A method of directly forming an SnO 2 film or the like by an ion plating method, a method of forming a metal Sn film or the like, and then subjecting it to heat treatment for oxidation, or plasma polymerization of an organometallic monomer containing Sn to form a plasma polymerized film. The heat treatment is performed (Japanese Patent Laid-Open No. 63-261,148).
【０００８】こうした金属酸化物半導体薄膜上には、こ
の薄膜の膜厚の約2〜5倍に当たる約0.3〜2.5μmの膜厚
を有する二酸化けい素膜が積層され被覆する。二酸化け
い素膜の膜厚がこれ以下では、湿度依存性が依然として
大きく、またこれ以上の膜厚にすると、湿度依存性は小
さいものの、被検ガスに対する感度が低下するようにな
る。このような膜厚の二酸化けい素膜の形成は、ＣＶＤ
法やスクリ−ン印刷法などによって行われる。On such a metal oxide semiconductor thin film, a silicon dioxide film having a thickness of about 0.3 to 2.5 μm, which is about 2 to 5 times the thickness of this thin film, is laminated and coated. When the film thickness of the silicon dioxide film is less than this, the humidity dependence is still large, and when the film thickness is more than this, the sensitivity to the test gas is lowered although the humidity dependence is small. The formation of the silicon dioxide film having such a film thickness is performed by CVD.
Method or screen printing method.
【０００９】[0009]
【発明の効果】ガス感応性膜としての金属酸化物半導体
薄膜上に、これに密着した形の二酸化けい素膜を積層し
被覆することにより、水蒸気のガス感応性膜への接触度
合いを低下させることで耐湿性の向上が図られており、
これによって水蒸気雰囲気中での経時的抵抗変化率をき
わめて小さなものとすることができる。The degree of contact of water vapor with the gas-sensitive film is reduced by laminating and covering the metal oxide semiconductor thin film as the gas-sensitive film with the silicon dioxide film in a form in close contact therewith. Therefore, the moisture resistance is improved,
As a result, the rate of resistance change with time in a steam atmosphere can be made extremely small.
【００１０】[0010]
【実施例】次に、実施例について本発明を説明する。EXAMPLES The present invention will now be described with reference to examples.
【００１１】実施例 アルミナ基板の表面上に、金ペーストの厚膜からなる対
向くし形電極を設け、この電極を覆うように、酸化錫膜
をプラズマＣＶＤ法により約300nmの膜厚で形成させ
た。次いで、この酸化錫膜上に、やはりプラズマＣＶＤ
法により、膜厚約1.5μmの二酸化けい素膜を形成させ
た。EXAMPLE An opposing comb-shaped electrode made of a thick film of gold paste was provided on the surface of an alumina substrate, and a tin oxide film was formed by plasma CVD to a thickness of about 300 nm so as to cover the electrode. . Then, plasma CVD is performed on the tin oxide film.
A silicon dioxide film having a thickness of about 1.5 μm was formed by the method.
【００１２】このようにして作製されたガスセンサにつ
いて、25℃、45%RHの水蒸気雰囲気中で、400℃の素子温
度での素子抵抗変化率を測定すると、図１に示されるよ
うな結果が得られた。この実施例での○、□、△は各サ
ンプルロットを示し、一方比較例(実施例においてSiO2
膜を設けないガスセンサ)においても同様である。When the element resistance change rate at an element temperature of 400 ° C. was measured in a water vapor atmosphere of 25 ° C. and 45% RH for the gas sensor thus manufactured, the results shown in FIG. 1 were obtained. Was given. In this example, ○, □, and Δ represent each sample lot, while the comparative example (SiO 2 in the example
The same applies to a gas sensor without a film).
【図１】実施例および比較例のガスセンサにおける経時
的素子抵抗変化率を示すグラフである。FIG. 1 is a graph showing an element resistance change rate with time in gas sensors of Examples and Comparative Examples.
Claims (1)
覆う金属酸化物半導体薄膜上に、二酸化けい素膜を積層
し被覆してなるガスセンサ。1. A gas sensor comprising a metal oxide semiconductor thin film covering a set of electrodes formed on an insulating substrate, and a silicon dioxide film laminated and covered thereon.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22486292A JPH0650919A (en) | 1992-07-31 | 1992-07-31 | Gas sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22486292A JPH0650919A (en) | 1992-07-31 | 1992-07-31 | Gas sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0650919A true JPH0650919A (en) | 1994-02-25 |
Family
ID=16820335
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22486292A Pending JPH0650919A (en) | 1992-07-31 | 1992-07-31 | Gas sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0650919A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003060500A1 (en) * | 2002-01-16 | 2003-07-24 | Matsushita Electric Industrial Co., Ltd. | Gas sensor freshness-keeping device |
| US7276745B2 (en) | 2005-02-22 | 2007-10-02 | Ngk Spark Plug Co., Ltd. | Gas sensor |
| US7412871B2 (en) | 2005-02-24 | 2008-08-19 | Ngk Spark Plug Co., Ltd. | Oxidizing gas sensor and production method thereof |
-
1992
- 1992-07-31 JP JP22486292A patent/JPH0650919A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003060500A1 (en) * | 2002-01-16 | 2003-07-24 | Matsushita Electric Industrial Co., Ltd. | Gas sensor freshness-keeping device |
| US7276745B2 (en) | 2005-02-22 | 2007-10-02 | Ngk Spark Plug Co., Ltd. | Gas sensor |
| US7412871B2 (en) | 2005-02-24 | 2008-08-19 | Ngk Spark Plug Co., Ltd. | Oxidizing gas sensor and production method thereof |
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