JPH0113056B2 - - Google Patents
Info
- Publication number
- JPH0113056B2 JPH0113056B2 JP55098815A JP9881580A JPH0113056B2 JP H0113056 B2 JPH0113056 B2 JP H0113056B2 JP 55098815 A JP55098815 A JP 55098815A JP 9881580 A JP9881580 A JP 9881580A JP H0113056 B2 JPH0113056 B2 JP H0113056B2
- Authority
- JP
- Japan
- Prior art keywords
- silicon
- layer
- semiconductor wafer
- electrical resistance
- 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
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
- G01N27/121—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid for determining moisture content, e.g. humidity, of the fluid
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
- Non-Adjustable Resistors (AREA)
Description
【発明の詳細な説明】
本発明は電気抵抗式湿度センサ及びその製造方
法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrical resistance type humidity sensor and a method for manufacturing the same.
従来、相対湿度の測定に際して機械的及び電気
抵抗式のセンサが種々、使用されている。電気抵
抗式湿度センサは感応速度が比較的速く、構造が
コンパクトで、しかも適応性の点でも機械式湿度
センサより優れている。その代表的なものは周囲
の湿度に応じて電気抵抗が変化する表面、例えば
特許公報昭54−26913号に記載のようなスルホン
化したポリスチレン薄層を設けた湿度センサであ
る。従来の電気式湿度センサにおいては前記感知
層に接着して互いに間隔を保つて配置した一対の
薄い電極間の電気抵抗変化を測定するが、一般に
感湿層の電気抵抗は非常に高く、電極の対向面積
を大きくとるか、又は電極の間隔を小さくして湿
度センサの電気抵抗値の低減を図つていた。ここ
で湿度センサの電気抵抗値の低減を図るのは、電
気抵抗値が大きいと湿度センサ出力の測定回路が
複雑になり、しかも外来雑音及びリーク抵抗の影
響を受けやすく、精度の良いセンサ出力の検出が
困難になるという理由に基づくものである。 Conventionally, various mechanical and electrical resistance sensors have been used to measure relative humidity. Electrical resistance humidity sensors have a relatively fast response speed, a compact structure, and are superior to mechanical humidity sensors in terms of adaptability. A typical example is a humidity sensor provided with a thin layer of sulfonated polystyrene, as described in Japanese Patent Publication No. 54-26913, for example, as described in Japanese Patent Publication No. 54-26913. Conventional electrical humidity sensors measure the change in electrical resistance between a pair of thin electrodes that are adhered to the sensing layer and placed at a distance from each other. Attempts have been made to reduce the electrical resistance value of the humidity sensor by increasing the facing area or by reducing the interval between the electrodes. The reason why we aim to reduce the electrical resistance value of the humidity sensor is that if the electrical resistance value is large, the measurement circuit for the humidity sensor output becomes complex, and it is also easily affected by external noise and leakage resistance. This is based on the reason that detection becomes difficult.
従来の電気抵抗式湿度センサにおいては電極を
写真印刷法により製造していた為に、寸法精度上
の制約から電極間隔を更に小さくすることは不可
能であり、それ故電気式湿度センサの小型化は困
難であつた（特開昭48−17781号公報参照）。 In conventional electrical resistance humidity sensors, the electrodes were manufactured using a photo printing method, so it was impossible to further reduce the electrode spacing due to dimensional accuracy constraints, so miniaturization of electrical humidity sensors was required. It was difficult (see Japanese Patent Application Laid-open No. 17781/1983).
本発明の目的は電気抵抗値が小さく且つ小型化
を図つた電気抵抗式湿度センサの製造方法を提供
することにある。 An object of the present invention is to provide a method for manufacturing an electrical resistance humidity sensor that has a small electrical resistance value and is miniaturized.
本発明の第１の特徴は基板にシリコンを使用
し、そのシリコン半導体ウエハと電極間に設けら
れる絶縁層を耐水性及び化学的安定性を有する窒
化シリコンで形成し、更に一対の電極を化学的に
安定で且つエツチング等の精密加工法によりその
間隙の狭小化が可能なポリシリコンで形成したこ
とにある。 The first feature of the present invention is to use silicon for the substrate, to form an insulating layer between the silicon semiconductor wafer and the electrodes from silicon nitride, which has water resistance and chemical stability, and to form a pair of electrodes by chemically The reason is that it is made of polysilicon, which is stable and whose gap can be narrowed by precision processing methods such as etching.
本発明の第２の特徴は周囲の湿度に応じて抵抗
値が変化する感湿材で被覆する本体部材を、半導
体プロセスにより精密加工し、特に一対の電極間
隙を微少にすることにより電気抵抗式湿度センサ
の小型化を図ることにある。 The second feature of the present invention is that the main body member, which is coated with a moisture-sensitive material whose resistance value changes depending on the surrounding humidity, is precisely processed using a semiconductor process, and in particular, by making the gap between a pair of electrodes very small, an electric resistance type The objective is to miniaturize the humidity sensor.
以下、本発明の実施例を図面に基づいて説明す
る。第１図及び第２図に本発明に係る電気抵抗式
湿度センサの構造を示す。これらの図において１
はシリコン半導体ウエハであり、該半導体シリコ
ンウエハ１上には酸化シリコン（SiO2）で第１
の絶縁層２が形成されている。この第１の絶縁層
２は電気的絶縁機能を有することは勿論である
が、緩衝材としての機能を有する。また第１の絶
縁層２の上には窒化シリコン（Si3N4）で第２の
絶縁層３が形成され、第２絶縁層３上にはリンイ
オン又はボロンイオンを注入したポリシリコンで
形成された間隙の狭い一対の櫛形電極４，４が相
互に嵌合状態で配置され、これらの櫛形電極４，
４の端部にはチタン、パラジウム、金等で接続端
子５，５が形成されている。 Embodiments of the present invention will be described below based on the drawings. FIGS. 1 and 2 show the structure of an electrical resistance type humidity sensor according to the present invention. In these figures 1
is a silicon semiconductor wafer, and a first layer of silicon oxide (SiO 2 ) is formed on the semiconductor silicon wafer 1.
An insulating layer 2 is formed. This first insulating layer 2 not only has an electrical insulating function but also a buffering function. Further, a second insulating layer 3 is formed of silicon nitride (Si 3 N 4 ) on the first insulating layer 2, and a second insulating layer 3 is formed of polysilicon into which phosphorus ions or boron ions are implanted. A pair of comb-shaped electrodes 4, 4 with a narrow gap are arranged in a mutually fitted state, and these comb-shaped electrodes 4,
Connecting terminals 5, 5 are formed at the ends of 4 using titanium, palladium, gold, or the like.
更に前記櫛形電極４，４は周囲の湿度に応じて
抵抗値が変化する感湿材６で被覆されている。感
湿材としては塩化リチウム含有のポリビニールア
ルコール、スルホン化したポリスチレン、各種セ
ラミツク材等が使用される。 Furthermore, the comb-shaped electrodes 4, 4 are covered with a moisture-sensitive material 6 whose resistance value changes depending on the surrounding humidity. As the moisture sensitive material, polyvinyl alcohol containing lithium chloride, sulfonated polystyrene, various ceramic materials, etc. are used.
次に第１図及び第２図に示した電気抵抗式湿度
センサの製造工程を第３図に基づいて説明する。 Next, the manufacturing process of the electrical resistance type humidity sensor shown in FIGS. 1 and 2 will be explained based on FIG. 3.
まず、ステツプ10でシリコン半導体ウエハを洗
浄して表面を清浄にし次のステツプ12で熱酸化に
よりウエハ表面に数百Å厚さの酸化シリコンで第
１の絶縁層を形成する。更にステツプ14で前記第
１の絶縁層上に化学的気相成長法（以下CVD法
と略す）により窒化シリコンで数百Åの厚さの第
２の絶縁層を形成する。 First, in step 10, a silicon semiconductor wafer is washed to clean the surface, and in step 12, a first insulating layer of silicon oxide with a thickness of several hundred angstroms is formed on the wafer surface by thermal oxidation. Furthermore, in step 14, a second insulating layer of several hundred angstroms thick is formed of silicon nitride on the first insulating layer by chemical vapor deposition (hereinafter abbreviated as CVD).
次にステツプ16で第２の絶縁層上にCVD法に
より数ミクロンの厚さのポリシリコン層を形成す
る。次いでステツプ18で前記ポリシリコン層にボ
ロンイオン又はリンイオンのイオン打込みを行
い、電極の電気抵抗値を低減する。このステツプ
18の工程ではイオン打込みの代りに拡散法により
イオン注入を行つてもよい。更にステツプ20では
ホトエツチングにより上記ポリシリコン層の不要
部分を除去して、間隔の狭い一対の櫛形状のポリ
シリコン電極を形成する。続いて、ステツプ22で
はホトエツチングにより、切離し部分の窒化シリ
コンを除去する。 Next, in step 16, a polysilicon layer with a thickness of several microns is formed on the second insulating layer by CVD. Next, in step 18, boron ions or phosphorus ions are implanted into the polysilicon layer to reduce the electrical resistance of the electrode. This step
In step 18, ion implantation may be performed by a diffusion method instead of ion implantation. Furthermore, in step 20, unnecessary portions of the polysilicon layer are removed by photoetching to form a pair of narrowly spaced comb-shaped polysilicon electrodes. Subsequently, in step 22, the silicon nitride at the separated portion is removed by photoetching.
尚、ステツプ20、22においてポリシリコン又は
窒化シリコンをホトエツチングにより加工する例
について説明したが、これに限定されることな
く、他のエツチング法でもよい。 Although an example has been described in which polysilicon or silicon nitride is processed by photoetching in steps 20 and 22, the present invention is not limited to this, and other etching methods may be used.
更にステツプ24乃至ステツプ28では蒸着法によ
りチタン、パナジウム、金を順次蒸着し、第１図
に示すような接続端子５を形成する。この後、ス
テツプ30で各チツプを切り離し、次のステツプ32
でパツケージに装着し、更にステツプ34で接続端
子５へリード付けし、最後にステツプ36で感湿層
を塗布して湿度センサが完成する。 Furthermore, in steps 24 to 28, titanium, panadium, and gold are sequentially deposited by a vapor deposition method to form the connection terminal 5 as shown in FIG. After this, step 30 separates each chip, and the next step 32
The humidity sensor is attached to the package in step 34, and leads are attached to the connection terminals 5 in step 34. Finally, a moisture sensitive layer is applied in step 36 to complete the humidity sensor.
そこで、窒化シリコンは良好な電気絶縁物であ
ると同時に、耐水性も良好であるので、湿度セン
サに適する材質である。また酸化シリコンは本発
明に係る湿度センサの測定回路部も含めて１チツ
プ化する時に特に必要になるが、センサ部単体の
みの時は除去することも可能である。 Therefore, silicon nitride is a material suitable for humidity sensors because it is a good electrical insulator and also has good water resistance. Furthermore, although silicon oxide is particularly required when the humidity sensor according to the present invention is integrated into a single chip including the measurement circuit section, it can be removed when only the sensor section is used alone.
ポリシリコンはボロンイオン又はリンイオンの
イオン打込みにより固有抵抗値を低減でき、しか
も耐水性があり化学的に安定であるので、湿度セ
ンサの電極に適する。湿度センサの電極をアルミ
ニウムの薄膜などにすると、感湿層塗布時に容易
に溶解して切断するなどの問題が生じる。同じ理
由で、電極の接続端子５はチタン、パラジウム、
金の蒸着層にしており、アルミニウムは使用しな
い。測定回路を１チツプ上に形成し、測定回路ま
でポリシリコンの電極を延長できる場合はこの接
続端子５を省略できる。 Polysilicon is suitable for humidity sensor electrodes because its specific resistance can be reduced by implanting boron ions or phosphorus ions, and it is also water resistant and chemically stable. If the electrodes of the humidity sensor are made of a thin aluminum film or the like, problems arise such as the film easily melting and being cut when the humidity sensitive layer is applied. For the same reason, the electrode connection terminal 5 is made of titanium, palladium,
It uses a vapor-deposited gold layer and does not use aluminum. If the measuring circuit is formed on one chip and the polysilicon electrode can be extended to the measuring circuit, the connecting terminal 5 can be omitted.
一対のポリシリコン電極間隔を約10ミクロンに
し、スルホン化したポリスチレン樹脂を感湿層と
したときの、相対湿度−電気抵抗性の測定例を第
４図に示す。２mm角以下で、従来の湿度センサと
比較して約２桁面積が少ないのにも拘らず、電気
抵抗値は従来のとほぼ同じであり、相対湿度に対
して指数関数的に変化する。それゆえ、本発明の
一実施例によれば、狭い空間の湿度を検出できる
効果がある。また耐水性のあるポリシリコン、窒
化シリコンで夫々、電極及び絶縁層を形成し、耐
蝕性のあるチタン、パラジウム、金で接続端子を
形成するように構成したので、長期安定性のある
湿度センサが得られるという効果がある。更に半
導体の測定回路を含めて１チツプにできるので、
外来の電気的雑音の影響を受けにくいという効果
もある（シリコン基板をそのために使用してい
る）。 FIG. 4 shows an example of relative humidity-electrical resistance measurement when the distance between a pair of polysilicon electrodes is about 10 microns and a sulfonated polystyrene resin is used as the moisture sensitive layer. Although it is less than 2 mm square, which is about two orders of magnitude smaller in area than conventional humidity sensors, the electrical resistance value is almost the same as conventional humidity sensors and changes exponentially with relative humidity. Therefore, according to one embodiment of the present invention, it is possible to detect humidity in a narrow space. In addition, the electrodes and insulating layers are made of water-resistant polysilicon and silicon nitride, and the connection terminals are made of corrosion-resistant titanium, palladium, and gold, so the humidity sensor has long-term stability. There is an effect that can be obtained. Furthermore, since it can be made into one chip including the semiconductor measurement circuit,
It also has the effect of being less susceptible to external electrical noise (a silicon substrate is used for this purpose).
第１図及び第２図に示すような構成の湿度セン
サを第３図に示すような製造工程で作成する実施
例について説明したが、本発明はこの実施例に限
定されず、前記の構造の変形例えば電極の形状変
形したものも、本発明の範囲内であるのも勿論で
ある。 Although an embodiment has been described in which a humidity sensor having a structure as shown in FIGS. 1 and 2 is produced by a manufacturing process as shown in FIG. 3, the present invention is not limited to this embodiment. Of course, modifications, for example, modifications in the shape of the electrode, are also within the scope of the present invention.
以上に説明した如く、本発明によれば当該湿度
センサの電極を、ポリシリコン層の不要部分をホ
トエツチング等のエツチングにより除去すること
によつて製造するため、一対の電極の間隔を小さ
くすること、更には電極の対向面積を大きくする
ことを容易に行なえる。よつて、電気抵抗が小さ
く且つ小型化を図つた電気抵抗式湿度センサが得
られる。 As explained above, according to the present invention, since the electrodes of the humidity sensor are manufactured by removing unnecessary portions of the polysilicon layer by etching such as photoetching, the distance between the pair of electrodes is reduced; Furthermore, the opposing area of the electrodes can be easily increased. Therefore, it is possible to obtain an electrical resistance type humidity sensor that has low electrical resistance and is miniaturized.
第１図及び第２図は本発明に係る電気抵抗式湿
度センサの構造を示し、第１図は平面図、第２図
は第１図のＡ−A′線における断面図、第３図は
本発明に係る電気抵抗式湿度センサの製造工程を
示すフローチヤート第４図は相対湿度に対する電
気抵抗の変化を示すグラフである。
１……シリコン半導体ウエハ、２，３……絶縁
層、４……電極、５……接続端子、６……感湿
層。
1 and 2 show the structure of an electrical resistance type humidity sensor according to the present invention, FIG. 1 is a plan view, FIG. 2 is a sectional view taken along line A-A' in FIG. FIG. 4, a flowchart showing the manufacturing process of the electrical resistance type humidity sensor according to the present invention, is a graph showing changes in electrical resistance with respect to relative humidity. 1... Silicon semiconductor wafer, 2, 3... Insulating layer, 4... Electrode, 5... Connection terminal, 6... Moisture sensitive layer.
Claims (1)
と、前記シリコン半導体ウエハを洗浄した後に化
学的気相成長法によりシリコン半導体ウエハ表面
上に窒化シリコン層を形成する第２の工程と、前
記窒化シリコン層の上に化学的気相成長法により
ポリシリコン層を形成する第３の工程と、前記ポ
リシリコン層にボロンイオン又はリンイオンを注
入する第４の工程と、前記ポリシリコン層の不要
部分をエツチングにより除去して一対の電極を形
成する第５の工程と、前記窒化シリコン層の切り
離し部分をエツチングにより除去する第６の工程
と、前記電極を周囲の湿度に応じて抵抗値が変化
する感湿材で被覆する工程と、を含む電気抵抗式
湿度センサの製造方法。 ２ 前記第２の工程において、前記シリコン半導
体ウエハを洗浄した後、熱酸化により前記シリコ
ン半導体ウエハ表面上に酸化シリコン層を形成
し、更に該酸化シリコン層の表面に化学的気相成
長法により窒化シリコン層を形成する特許請求の
範囲第１項に記載の電気抵抗式湿度センサの製造
方法。[Claims] 1. A first step of cleaning a silicon semiconductor wafer, and a second step of forming a silicon nitride layer on the surface of the silicon semiconductor wafer by chemical vapor deposition after cleaning the silicon semiconductor wafer. a third step of forming a polysilicon layer on the silicon nitride layer by chemical vapor deposition; a fourth step of implanting boron ions or phosphorus ions into the polysilicon layer; a fifth step of removing unnecessary portions of the silicon nitride layer by etching to form a pair of electrodes, a sixth step of removing the separated portions of the silicon nitride layer by etching, and adjusting the resistance of the electrodes according to the surrounding humidity. A method for manufacturing an electrical resistance humidity sensor, comprising the step of coating with a moisture-sensitive material whose temperature changes. 2 In the second step, after cleaning the silicon semiconductor wafer, a silicon oxide layer is formed on the surface of the silicon semiconductor wafer by thermal oxidation, and nitriding is further performed on the surface of the silicon oxide layer by chemical vapor deposition. A method for manufacturing an electrical resistance humidity sensor according to claim 1, wherein a silicon layer is formed.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9881580A JPS5723848A (en) | 1980-07-21 | 1980-07-21 | Electronic resistance type moisture sensor and its manufacture |
| US06/361,903 US4642601A (en) | 1980-07-21 | 1981-07-20 | Humidity-sensitive element |
| EP81902028A EP0057728B1 (en) | 1980-07-21 | 1981-07-20 | Moisture-sensitive element, moisture-sensitive material and manufacturing method for same |
| DE8181902028T DE3174710D1 (en) | 1980-07-21 | 1981-07-20 | Moisture-sensitive element, moisture-sensitive material and manufacturing method for same |
| PCT/JP1981/000166 WO1982000362A1 (en) | 1980-07-21 | 1981-07-20 | Moisture-sensitive element,moisture-sensitive material and manufacturing method for same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9881580A JPS5723848A (en) | 1980-07-21 | 1980-07-21 | Electronic resistance type moisture sensor and its manufacture |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5723848A JPS5723848A (en) | 1982-02-08 |
| JPH0113056B2 true JPH0113056B2 (en) | 1989-03-03 |
Family
ID=14229813
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9881580A Granted JPS5723848A (en) | 1980-07-21 | 1980-07-21 | Electronic resistance type moisture sensor and its manufacture |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5723848A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003270189A (en) * | 2002-03-20 | 2003-09-25 | Denso Corp | Capacitive humidity sensor |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5212071B2 (en) * | 1972-08-19 | 1977-04-04 |
-
1980
- 1980-07-21 JP JP9881580A patent/JPS5723848A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5723848A (en) | 1982-02-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20020142478A1 (en) | Gas sensor and method of fabricating a gas sensor | |
| US6353381B1 (en) | Electrical temperature sensor having one or more layers | |
| US5048336A (en) | Moisture-sensitive device | |
| US6628501B2 (en) | Capacitive moisture sensor | |
| JP3542614B2 (en) | Temperature sensor and method for manufacturing the temperature sensor | |
| KR100488432B1 (en) | Capacitance type humidity sensor with passivation layer | |
| US20070062812A1 (en) | Gas sensor and method for the production thereof | |
| US4961833A (en) | Field-effect transistor-type semiconductor sensor | |
| US5231878A (en) | Mass air flow sensor | |
| EP0230104A2 (en) | Semiconductor gas sensor having thermally-isolated site | |
| US5211058A (en) | Capacitive pressure sensor and method of manufacturing the same | |
| US5488869A (en) | Capacitive absolute pressure measurement sensor and method of manufacturing a plurality of such sensors | |
| JP3551527B2 (en) | Method for manufacturing semiconductor strain-sensitive sensor | |
| WO1995020754A1 (en) | A capacitive pressure sensor having a reduced area dielectric spacer | |
| JPH0374947B2 (en) | ||
| US5917264A (en) | Electrostatic capacitance type transducer and method for producing the same | |
| EP1536490A1 (en) | Magnetoresistance effect element and production method and application method therefor | |
| JPH0113056B2 (en) | ||
| US20210148845A1 (en) | Sensor Device, Method for Manufacturing a Sensor Device and Sensor Assembly | |
| JPH06105235B2 (en) | Humidity detection element | |
| GB2078973A (en) | A moisture sensor formed by an electrical capacitor | |
| JPH0426432B2 (en) | ||
| JPS6258456B2 (en) | ||
| JP2002365256A (en) | Humidity sensor | |
| WO1992002797A1 (en) | Pressure sensor |