JPH0122963B2 - - Google Patents
Info
- Publication number
- JPH0122963B2 JPH0122963B2 JP58020366A JP2036683A JPH0122963B2 JP H0122963 B2 JPH0122963 B2 JP H0122963B2 JP 58020366 A JP58020366 A JP 58020366A JP 2036683 A JP2036683 A JP 2036683A JP H0122963 B2 JPH0122963 B2 JP H0122963B2
- Authority
- JP
- Japan
- Prior art keywords
- zinc oxide
- humidity
- thin film
- oxide thin
- humidity sensor
- 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.)
- Expired
Links
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 claims description 46
- 239000011787 zinc oxide Substances 0.000 claims description 23
- 239000010409 thin film Substances 0.000 claims description 19
- 238000001514 detection method Methods 0.000 description 8
- 239000000758 substrate Substances 0.000 description 7
- 238000004544 sputter deposition Methods 0.000 description 6
- 238000005259 measurement Methods 0.000 description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 239000010408 film Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 238000000137 annealing Methods 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 229910052573 porcelain Inorganic materials 0.000 description 2
- 238000005546 reactive sputtering Methods 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 238000007733 ion plating Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 150000002611 lead compounds Chemical class 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000007784 solid electrolyte Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Non-Adjustable Resistors (AREA)
- Investigating Or Analyzing Materials Using Thermal Means (AREA)
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
Description
【発明の詳細な説明】
この発明は鉛を含有した酸化亜鉛薄膜よりなる
湿度センサに関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a humidity sensor made of a zinc oxide thin film containing lead.
従来から存在する電気抵抗式の湿度センサとし
ては、櫛型電極上に固体電解質を高分子材料と架
橋重合させた有機物皮膜からなる湿度センサ、あ
るいは多孔性金属酸化物磁器を用いた湿度センサ
が知られている。しかしながら前者の有機物皮膜
からなる湿度センサは、高温での使用ができない
こと、長時間の結露した環境下では電解質が溶け
出すなどの欠点があつた。 Conventional electrical resistance humidity sensors include humidity sensors made of an organic film made by cross-linking a solid electrolyte with a polymeric material on a comb-shaped electrode, and humidity sensors using porous metal oxide porcelain. It is being However, the former humidity sensor made of an organic film has drawbacks such as not being able to be used at high temperatures and the electrolyte leaching out in an environment with long-term dew condensation.
また多孔性金属酸化物磁器を用いた湿度センサ
は初期においてはすぐれた湿度応答を有するもの
があるが、長時間使用すると、水分子が空孔の奥
深くに浸入し、化学吸着するようになり、表面抵
抗は上昇する。これを再生するため加熱によるク
リーニングが必要となり、ヒータ制御回路という
複雑な機構が必要である。 In addition, some humidity sensors using porous metal oxide porcelain have an excellent humidity response initially, but when used for a long time, water molecules penetrate deep into the pores and become chemically adsorbed. Surface resistance increases. To regenerate this, cleaning by heating is required, which requires a complicated mechanism called a heater control circuit.
一方酸化亜鉛を用いた湿度センサも従来からよ
く知られている。これはセラミツク、ガラスなど
の絶縁基板の上に酸化亜鉛の薄層を形成し、さら
にこの上に一対の検出電極を形成したものであ
る。この湿度センサは雰囲気の湿度が変化したと
き抵抗値が変化するという特性を有するものであ
り、応答性が速いという特徴をもつている。 On the other hand, humidity sensors using zinc oxide have also been well known. This consists of forming a thin layer of zinc oxide on an insulating substrate such as ceramic or glass, and further forming a pair of detection electrodes on this. This humidity sensor has a characteristic that its resistance value changes when the humidity of the atmosphere changes, and is characterized by quick response.
ところがこの抵抗値は実用測定範囲内にあるこ
とが重要であるが、酸化亜鉛の場合抵抗値をこの
実用測定範囲内に抑えることがむづかしく、また
この範囲内にコントロールするに用いる元素もあ
まり知られていない。 However, it is important that this resistance value be within the practical measurement range, but in the case of zinc oxide, it is difficult to keep the resistance value within this practical measurement range, and the elements used to control it within this range are not very effective. unknown.
この発明は抵抗値が実用測定範囲内にある酸化
亜鉛薄膜よりなる湿度センサを提供するべく検討
の結果、感湿要素が鉛を含有した酸化亜鉛薄膜よ
りなる湿度センサを提供するべく検討の結果、感
湿要素が鉛を含有した酸化亜鉛薄膜よりなる湿度
センサを見出したのである。 As a result of studies to provide a humidity sensor made of a zinc oxide thin film whose resistance value is within a practical measurement range, this invention was made to provide a humidity sensor made of a zinc oxide thin film whose humidity sensing element contains lead. They have discovered a humidity sensor in which the humidity sensing element is made of a zinc oxide thin film containing lead.
そしてこの湿度センサは、 (1) 湿度測定範囲が10％から90％まで広いこと。 And this humidity sensor is (1) The humidity measurement range is wide from 10% to 90%.
(2) 常温のみならず、200℃までの高温部におい
ても従来の有機物に比べてすぐれた感湿特性を
示すこと。(2) Exhibit superior moisture sensitivity characteristics compared to conventional organic materials, not only at room temperature but also in high-temperature areas up to 200℃.
(3) 実用測定範囲内の抵抗値を有すること。(3) Must have a resistance value within the practical measurement range.
(4) 加熱によるクリーニング処理なしで湿度の連
続流定が可能であること。(4) Continuous flow of humidity is possible without heating cleaning treatment.
などの効果を奏することがきるのである。It is possible to achieve the following effects.
以下この発明の湿度センサについて詳細を説明
する。 The humidity sensor of the present invention will be explained in detail below.
第１図はこの発明にかかる湿度センサの一例を
示す概略平面図である。 FIG. 1 is a schematic plan view showing an example of a humidity sensor according to the present invention.
１はセラミツク、ガラスなどの絶縁基板であ
り、この基板１上にはくし歯状の一対の検出電極
２，３が形成され、さらにくし歯部分を覆うよう
に感湿要素である酸化亜鉛薄膜４が形成されてい
る。 1 is an insulating substrate made of ceramic, glass, etc. A pair of comb-like detection electrodes 2 and 3 are formed on this substrate 1, and a zinc oxide thin film 4, which is a moisture-sensitive element, is further formed to cover the comb-like portions. It is formed.
５，６は検出電極２，３にそれぞれ接続された
端子である。なお、図示していないが、酸化亜鉛
薄膜４上に検出電極２，３を形成方法あるいは上
下平行電極によるバルク型のものであつてもよ
く、電極はAu，Ni，Cr，Ti，Cu，Feなどの導
電性物質をマスク蒸着法により形成すればよい。 5 and 6 are terminals connected to the detection electrodes 2 and 3, respectively. Although not shown, the detection electrodes 2 and 3 may be formed on the zinc oxide thin film 4 or may be of a bulk type with upper and lower parallel electrodes, and the electrodes may be made of Au, Ni, Cr, Ti, Cu, Fe. The conductive material may be formed using a mask vapor deposition method.
酸化亜鉛薄膜４を形成する手段としては、例え
ばスパツタリング法、真空蒸着法、イオンプレー
テイング法などがあり、特に形成手段の容易さか
ら反応性スパツタリング法が適している。 Examples of methods for forming the zinc oxide thin film 4 include sputtering, vacuum evaporation, and ion plating, with reactive sputtering being particularly suitable because of its ease of formation.
この発明において、感湿要素である酸化亜鉛薄
膜４に含有させる鉛の使用範囲としては0.1〜20
原子％、より好ましくは１〜５％が望ましい。 In this invention, the use range of lead contained in the zinc oxide thin film 4, which is a moisture sensitive element, is 0.1 to 20.
Atom %, more preferably 1 to 5% is desirable.
この理由は、鉛が0.1原子％以下では抵抗値は
108Ω以上になり、実用測定可能範囲を越え、ま
た20原子％以上になると湿度に対する抵抗変化が
小さくなり、何れも湿度センサとしては不適当な
ためである。 The reason for this is that when lead is less than 0.1 atomic%, the resistance value is
This is because if it exceeds 10 8 Ω, which exceeds the practical measurable range, and if it exceeds 20 atomic %, the resistance change with respect to humidity becomes small, and both are inappropriate as a humidity sensor.
以下この発明を一実施例により詳述する。 This invention will be explained in detail below using one example.
実施例
アルミナ基板上に、くし歯の間隔が0.5mm、対
向長が65mmの金からなるくし歯状の検出電極を形
成した。Example A comb-shaped detection electrode made of gold with a comb-teeth spacing of 0.5 mm and a facing length of 65 mm was formed on an alumina substrate.
さらにこの上にくし歯部分を覆うように、鉛を
含有する酸化亜鉛薄膜を形成した。この酸化酸化
亜鉛薄膜の形成は次のようにして行つた。 Furthermore, a zinc oxide thin film containing lead was formed on top of this to cover the comb teeth. This zinc oxide thin film was formed as follows.
くし歯状の検出電極を形成したアルミナ基板を
スパツタリング装置の陽極側に設置し、金属亜鉛
に鉛を３原子％含有させた合金をターゲツトとし
て陰極に配置した。そしてスパツタリング室内の
真空圧を５×10-7Torrとし、酸素（O2）とアル
ゴン（Ar）の比率50：50からなる混合ガスをス
パツタリング室内に導入し、該室内を３×
10-4Torrの圧力に保つた。 An alumina substrate on which a comb-shaped detection electrode was formed was placed on the anode side of a sputtering device, and an alloy of metallic zinc containing 3 atomic percent lead was placed on the cathode as a target. Then, the vacuum pressure in the sputtering chamber was set to 5×10 -7 Torr, a mixed gas consisting of oxygen (O 2 ) and argon (Ar) in a ratio of 50:50 was introduced into the sputtering chamber, and the chamber was heated to 3×
It was kept at a pressure of 10 -4 Torr.
その後排気弁を調整し、スパツタリング室圧力
が1.5×10-1Torrになるよう調整し、300Wの高周
波電源を供給してくし歯状の検出電極を有するア
ルミナ基板の上に鉛を含有する酸化亜鉛薄膜を形
成した。 Then, the exhaust valve was adjusted so that the sputtering chamber pressure was 1.5 × 10 -1 Torr, and a 300W high-frequency power supply was applied to the zinc oxide containing lead on an alumina substrate with a comb-shaped detection electrode. A thin film was formed.
なお、この実施例ではターゲツトとして金属亜
鉛を用い、反応性スパツタリング法により酸化亜
鉛薄膜を形成したが、ターゲツトとしてPbOなど
の鉛化合物を含有した酸化亜鉛焼結体を用いて酸
化亜鉛薄膜を形成してもよい。 In this example, metal zinc was used as a target and a zinc oxide thin film was formed by a reactive sputtering method, but a zinc oxide thin film was formed using a zinc oxide sintered body containing a lead compound such as PbO as a target. It's okay.
かくして得たスパツタリング法にもとづく酸化
亜鉛薄膜は、その形成時には表面に欠陥構造を多
く含み、ガスなどが吸着しやすいため、150℃、
24時間のアニールを行つた。このアニールにより
該酸化亜鉛薄膜の抵抗値は膜形成時より幾分高く
なるが、抵抗値の経時変化が小さくなる。 The thus obtained zinc oxide thin film based on the sputtering method contains many defective structures on the surface when it is formed, and gases etc. are easily adsorbed, so it is heated at 150℃.
24 hour annealing was performed. This annealing makes the resistance value of the zinc oxide thin film somewhat higher than when the film was formed, but the change in resistance value over time becomes small.
このようにして得られた湿度センサについて、
相対湿度に対する電気抵抗変化を測定したところ
第２図の如き結果が得られ、その応答性は相対湿
度95％の恒湿槽から55％の室内へ取出した場合平
衡湿度の90％に相当する抵抗値を示すのに20秒と
いう早さを示した。 Regarding the humidity sensor obtained in this way,
When we measured the change in electrical resistance with respect to relative humidity, we obtained the results shown in Figure 2.The response was as follows: When taken out from a humidity chamber with a relative humidity of 95% into a room with a humidity of 55%, the resistance corresponds to 90% of the equilibrium humidity. It took just 20 seconds to show the value.
これに対し、鉛を用いない酸化亜鉛のみ薄膜か
らなる湿度センサでは、抵抗値は低いが、相対湿
度50％までは抵抗値が緩やかに上昇し、相対湿度
50％でピークに達し、さらに相対湿度が上昇する
と逆に抵抗値が下降するようになり、実用上不適
当なものであつた。 On the other hand, a humidity sensor made of a thin film made only of zinc oxide, which does not use lead, has a low resistance value, but the resistance value gradually increases up to 50% relative humidity.
It reached a peak at 50%, and as the relative humidity further increased, the resistance value began to decrease, making it unsuitable for practical use.
第１図はこの発明にかかる湿度センサの一例を
示す概略平面図、第２図は相対湿度―電気抵抗特
性図である。
１……絶縁基板、２，３……検出電極、４……
酸化亜鉛薄膜。
FIG. 1 is a schematic plan view showing an example of a humidity sensor according to the present invention, and FIG. 2 is a relative humidity-electrical resistance characteristic diagram. 1... Insulating substrate, 2, 3... Detection electrode, 4...
Zinc oxide thin film.
Claims (1)
ることを特徴とする湿度センサ。 ２ 酸化亜鉛薄膜に含有する鉛の量が0.1〜20原
子％であることを特徴とする特許請求の範囲第１
項記載の湿度センサ。[Claims] 1. A humidity sensor characterized in that the humidity sensing element is made of a lead-containing zinc oxide thin film. 2. Claim 1, characterized in that the amount of lead contained in the zinc oxide thin film is 0.1 to 20 atomic %.
Humidity sensor as described in section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58020366A JPS59147401A (en) | 1983-02-09 | 1983-02-09 | Moisture sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58020366A JPS59147401A (en) | 1983-02-09 | 1983-02-09 | Moisture sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59147401A JPS59147401A (en) | 1984-08-23 |
| JPH0122963B2 true JPH0122963B2 (en) | 1989-04-28 |
Family
ID=12025078
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58020366A Granted JPS59147401A (en) | 1983-02-09 | 1983-02-09 | Moisture sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59147401A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8610180B2 (en) | 2010-06-11 | 2013-12-17 | Semiconductor Energy Laboratory Co., Ltd. | Gas sensor and method for manufacturing the gas sensor |
-
1983
- 1983-02-09 JP JP58020366A patent/JPS59147401A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59147401A (en) | 1984-08-23 |
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