JPS6136616B2 - - Google Patents
Info
- Publication number
- JPS6136616B2 JPS6136616B2 JP54093637A JP9363779A JPS6136616B2 JP S6136616 B2 JPS6136616 B2 JP S6136616B2 JP 54093637 A JP54093637 A JP 54093637A JP 9363779 A JP9363779 A JP 9363779A JP S6136616 B2 JPS6136616 B2 JP S6136616B2
- Authority
- JP
- Japan
- Prior art keywords
- electric heater
- upper layer
- cavity
- bridge
- sio
- 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
- 239000004020 conductor Substances 0.000 claims description 4
- 239000000758 substrate Substances 0.000 claims description 2
- 239000012777 electrically insulating material Substances 0.000 claims 2
- 239000003779 heat-resistant material Substances 0.000 claims 1
- 239000007789 gas Substances 0.000 description 14
- 235000012431 wafers Nutrition 0.000 description 9
- 229910004298 SiO 2 Inorganic materials 0.000 description 8
- 238000005530 etching Methods 0.000 description 7
- 239000000243 solution Substances 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 229910052681 coesite Inorganic materials 0.000 description 2
- 229910052906 cristobalite Inorganic materials 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 2
- 230000007257 malfunction Effects 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- 229910052682 stishovite Inorganic materials 0.000 description 2
- 229910052905 tridymite Inorganic materials 0.000 description 2
- DDFHBQSCUXNBSA-UHFFFAOYSA-N 5-(5-carboxythiophen-2-yl)thiophene-2-carboxylic acid Chemical compound S1C(C(=O)O)=CC=C1C1=CC=C(C(O)=O)S1 DDFHBQSCUXNBSA-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 238000007084 catalytic combustion reaction Methods 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000001259 photo etching Methods 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
Landscapes
- Measuring Volume Flow (AREA)
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
- Surface Heating Bodies (AREA)
- Semiconductor Integrated Circuits (AREA)
Description
【発明の詳細な説明】
本発明は、例えば、可燃性ガスが接触した時に
該可燃性ガスが燃焼して電気抵抗を変化させ、或
いは、一酸化炭素や塩素等の不燃性ガスが付着し
た時にこれらのガスに対応して電気抵抗を変化さ
せ、この電気抵抗の変化をブリツジ回路によつて
検出してガス検出器に使用するのに好適な電熱器
に関する。
一般に、接触燃焼式ガス検出器、或いは、半導
体ガス検出器においては、ガス検出素子に電熱器
を使用するが、その電熱器は、消費電力が少なく
かつ熱時定数の小さいものが望ましく、そのため
には、電熱器を小型化して熱容量を小さくする必
要がある。また、この種のガス検出器は、ガス検
出素子の電気抵抗の変化をブリツジ回路によつて
検出するようにしているものがほとんどである
が、その場合、ガス検出素子の電気抵抗が周囲条
件例えば周囲の温度変化等によつて変化してブリ
ツジ回路の平衡がくずれ誤動作することがある。
このようなブリツジ回路の誤動作を防止するため
に、従来より、検出素子と同一特性の補償抵抗を
ブリツジ回路に組み込むことが提案されている
が、接触燃焼式ガス検出器或いは半導体式ガス検
出器等においては電熱器をも含めた特性を同一に
する必要がある。しかし、従来の電熱器の構造に
よつたのでは同一特性の電熱器を製作することは
非常に困難かつ高価で、しかも、これらの電熱器
を２個接近して配設することは非常に困難であつ
た。
本発明は、上述のごとき実情に鑑みてなされた
もので、以下、図面を参照しながら詳細に説明す
る。
第１図は、本発明による電熱器の一実施例を説
明するための平面図、第２図は、第１図の−
線より見た断面図で、図中、１はシリコン（Si）
ウエハー等の基板、１０はSiウエハー１上に形成
されたシリコン熱酸化（SiO2）層で、このSiO2層
１０は耐熱性かつ電気絶縁性に富み、機械的強度
も比較的強く、また、エツチング液もSiウエハー
１とは異なつている。２はSiウエハー１に設けら
れた空洞、１１ａ，１１ｂ，１１ｃはSiO2層１
０に設けられたスリツトで、これら空洞及びスリ
ツトは、例えば、次のようにして作られる。ま
ず、Siウエハー１の表面を水蒸気雰囲気中におい
て、1100℃で、数時間熱酸化して厚み1.0μｍ程
度のSiO2層１０を成長させる。次にフオトレジ
スト・パターンを用いた公知のフオトエツチング
法によりSiO2層１０を、例えば、フツ化アンモ
ニウム系エツチング液でエツチングし、次いで、
Siウエハー１をシルバーグリコールエツチング液
等の結晶方向によつてエツチング速度があまり変
らないエツチング液を用いてエツチングして適当
な深さの溝を作る。その後、Siの異方性エツチン
グ液であり、かつ、SiO2はほとんど侵さないエ
チレンジアミン水溶液等を用いたエツチング液で
前記溝の両側面を積極的にエツチングするととも
に、各溝間をアンダーカツトによつて貫通させて
空洞２及びスリツト１１ａ，１１ｂ，１１ｃを形
成し、SiO2の橋１０ａ，１０ｂを作る。斯様に
して形成した基板の上に被検出ガスに対して触媒
作用を有する導電性物質、例えば、Ｐt、又は、
抵抗温度係数の大きい抵抗体にＰtやＰd等を混合
した物質をスパツタリングして導電体層１３を形
成するとともに、橋１０ａ，１０ｂの上に橋架部
１３ａ，１３ｂを形成、導電体層１３にリード線
１５ａ，１５ｂ，１５ｃを設け、リード線１５
ａ，１５ｃ間及び１５ｂ，１５ｃ間に電流を流す
と橋架部１３ａ，１３ｂが発熱し、ここに同一特
性の電熱器を２個接近して形成することができ
る。従つて、このうち一方の橋架部を被検出ガス
に対して不活性な物質例えばSiO2膜等で被覆す
ると補償用の電熱器として使用することができ
る。
第３図は、第１図の実施例の変形例を示す平面
図、第４図は、第３図の−線よりみた断面
図、第５図は、第３図の−線よりみた断面図
で、図中、第１図及び第２図に示した実施例と同
様な作用をする部分には同一の参照番号が付して
ある。この実施例は、Siウエハー１に２個の空洞
２ａ，２ｂを設けるとともに、各空洞２ａ，２ｂ
の上部にSiO2層の橋１０ａ，１０ｂ（図示せ
ず）を形成し、これらの橋１０ａ，１０ｂの上に
導電性物質の発熱部１３ａ，１３ｂを形成したも
のである。
以上の説明から明らかなように、本発明による
と、消費電力及び熱時定数が小さく、かつ、特性
の略等しい２個の発熱部を２個近接して設けるこ
とができ、しかも、各発熱部の一方を共通電極と
した小型でかつブリツジに組み込み容易な電熱器
を提供することができる。なお、以上に本発明に
よる電熱器がガス検出器に適用した場合を例とし
て説明したが、本発明による電熱器は、ガス検出
器に限定されるものではなく、例えば、発熱によ
る抵抗変化を利用した熱線流速計、或いは、ピラ
ニー真空計等にも利用できることは容易に理解で
きよう。 DETAILED DESCRIPTION OF THE INVENTION The present invention can be used, for example, when flammable gases come into contact with each other, causing the flammable gas to burn and change electrical resistance, or when non-flammable gases such as carbon monoxide or chlorine are attached. The present invention relates to an electric heater that changes electrical resistance in response to these gases, detects this change in electrical resistance using a bridge circuit, and is suitable for use in a gas detector. Generally, in catalytic combustion type gas detectors or semiconductor gas detectors, an electric heater is used for the gas detection element, but it is desirable that the electric heater consumes less power and has a small thermal time constant. Therefore, it is necessary to downsize the electric heater and reduce its heat capacity. In addition, most of this type of gas detector uses a bridge circuit to detect changes in the electrical resistance of the gas detection element. Changes due to changes in ambient temperature, etc. may cause the bridge circuit to become unbalanced and malfunction.
In order to prevent such malfunctions of the bridge circuit, it has been proposed to incorporate a compensation resistor with the same characteristics as the detection element into the bridge circuit. In this case, it is necessary to make the characteristics including the electric heater the same. However, it is extremely difficult and expensive to manufacture electric heaters with the same characteristics using the conventional electric heater structure, and it is also extremely difficult to arrange two of these electric heaters in close proximity. It was hot. The present invention has been made in view of the above-mentioned circumstances, and will be described in detail below with reference to the drawings. FIG. 1 is a plan view for explaining an embodiment of the electric heater according to the present invention, and FIG.
This is a cross-sectional view taken along the line. In the figure, 1 is silicon (Si).
A substrate such as a wafer, 10 is a silicon thermal oxidation (SiO 2 ) layer formed on the Si wafer 1 ;
No. 10 has excellent heat resistance and electrical insulation, and has relatively strong mechanical strength, and the etching solution is also suitable for Si wafers.
It is different from 1 . 2 is a cavity provided in the Si wafer 1 , 11a, 11b, 11c are SiO 2 layer 1
These cavities and slits are made, for example, as follows. First, the surface of the Si wafer 1 is thermally oxidized in a steam atmosphere at 1100° C. for several hours to grow an SiO 2 layer 10 with a thickness of about 1.0 μm. Next, the SiO 2 layer 10 is etched by a known photoetching method using a photoresist pattern with, for example, an ammonium fluoride-based etching solution, and then,
A Si wafer 1 is etched using an etching solution such as a silver glycol etching solution whose etching rate does not change much depending on the crystal direction to form grooves of appropriate depth. After that, both sides of the grooves are actively etched using an etching solution such as ethylenediamine aqueous solution, which is an anisotropic etching solution for Si and hardly attacks SiO 2 , and undercuts are made between each groove. A cavity 2 and slits 11a, 11b, 11c are formed by passing through the SiO 2 bridges 10a, 10b. A conductive substance having a catalytic effect on the gas to be detected, such as P t or
The conductor layer 13 is formed by sputtering a substance mixed with P t , P d, etc. on a resistor having a large temperature coefficient of resistance, and bridge portions 13a and 13b are formed on the bridges 10a and 10b. Lead wires 15a, 15b, 15c are provided in the lead wire 15.
When a current is passed between a and 15c and between 15b and 15c, the bridge parts 13a and 13b generate heat, and two electric heaters with the same characteristics can be formed close together here. Therefore, if one of the bridge parts is coated with a substance inert to the gas to be detected, such as a SiO 2 film, it can be used as a compensation electric heater. 3 is a plan view showing a modification of the embodiment shown in FIG. 1, FIG. 4 is a sectional view taken along the - line in FIG. 3, and FIG. 5 is a sectional view taken along the - line in FIG. 3. In the figures, parts having the same functions as those in the embodiment shown in FIGS. 1 and 2 are given the same reference numerals. In this embodiment, two cavities 2a, 2b are provided in the Si wafer 1 , and each cavity 2a, 2b is
Bridges 10a and 10b (not shown) made of SiO 2 layer are formed on top of the wafer, and heating parts 13a and 13b made of conductive material are formed on these bridges 10a and 10b. As is clear from the above description, according to the present invention, it is possible to provide two heat generating parts close to each other with small power consumption and thermal time constant and having substantially the same characteristics. It is possible to provide an electric heater that is small and easy to incorporate into a bridge, with one side of the electrode serving as a common electrode. Although the electric heater according to the present invention is applied to a gas detector as an example above, the electric heater according to the present invention is not limited to a gas detector. It is easy to understand that the present invention can also be used for hot wire anemometers, Pirani vacuum gauges, etc.
第１図は、本発明による電熱器の一実施例を説
明するための平面図、第２図は、第１図の−
線よりみた断面図、第３図は、本発明による電熱
器の変形例を示す平面図、第４図は、第３図の
−線よりみた断面図、第５図は、第３図の−
線よりみた断面図である。
１……Siウエハー、２，２ａ，２ｂ……空洞、
１０……SiO2層、１０ａ，１０ｂ……SiO2の
橋、１３……導電体層、１３ａ，１３ｂ……発熱
部、１５ａ，１５ｂ，１５ｃ……リード線。
FIG. 1 is a plan view for explaining an embodiment of the electric heater according to the present invention, and FIG.
3 is a plan view showing a modified example of the electric heater according to the present invention, FIG. 4 is a sectional view taken from the - line in FIG. 3, and FIG. 5 is a sectional view taken from the - line in FIG.
It is a sectional view taken along the line. 1...Si wafer, 2, 2a, 2b...cavity,
DESCRIPTION OF SYMBOLS 10... SiO2 layer, 10a, 10b... SiO2 bridge, 13...Conductor layer, 13a, 13b...Heating part, 15a, 15b, 15c...Lead wire.
Claims (1)
と該上部層とは異なる物質の電気絶縁性物質から
成る下部層とを含む基板を用い、前記下部層の一
部を除去して前記上部層の下部に空洞を形成し、
該空洞上に該空洞を橋架する２個の橋部を近接し
て前記上部層にて形成し、前記上部層の上に導電
性物質を配して前記橋部に発熱部を形成すること
を特徴とする電熱器。1 Using a substrate including an upper layer made of a heat-resistant and electrically insulating material and a lower layer made of an electrically insulating material different from the upper layer, a part of the lower layer is removed to form the upper layer. form a cavity at the bottom of the
Two bridge parts bridging the cavity are formed in the upper layer adjacent to each other on the cavity, and a conductive material is disposed on the upper layer to form a heat generating part in the bridge part. Characteristic electric heater.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9363779A JPS5618381A (en) | 1979-07-25 | 1979-07-25 | Electric heater |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9363779A JPS5618381A (en) | 1979-07-25 | 1979-07-25 | Electric heater |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5618381A JPS5618381A (en) | 1981-02-21 |
| JPS6136616B2 true JPS6136616B2 (en) | 1986-08-19 |
Family
ID=14087851
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9363779A Granted JPS5618381A (en) | 1979-07-25 | 1979-07-25 | Electric heater |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5618381A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01239102A (en) * | 1988-03-18 | 1989-09-25 | Mitsubishi Rayon Co Ltd | Disposable diaper |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5811139A (en) * | 1981-07-14 | 1983-01-21 | 東燃株式会社 | Metal evaporated polypropylene film |
| EP0076935B1 (en) * | 1981-10-09 | 1989-07-19 | Honeywell Inc. | Integrated semiconductor device and method of fabricating said device |
| JPS5872059A (en) * | 1981-10-09 | 1983-04-28 | ハネウエル・インコ−ポレ−テツド | Semiconductor device and its manufacture |
| JPS58154652A (en) * | 1982-03-10 | 1983-09-14 | Toshiba Corp | Gas sensitive element |
| JPS5957118A (en) * | 1982-09-28 | 1984-04-02 | Japan Electronic Control Syst Co Ltd | Flow meter |
| JPS604814A (en) * | 1983-06-23 | 1985-01-11 | Nippon Soken Inc | Semiconductor type flow rate detector |
| JPS6013220A (en) * | 1983-07-04 | 1985-01-23 | Esutetsuku:Kk | Gas flow sensor and manufacture thereof |
| JPS60142268A (en) * | 1983-12-27 | 1985-07-27 | 株式会社山武 | Flow rate sensor |
| US4576050A (en) * | 1984-08-29 | 1986-03-18 | General Motors Corporation | Thermal diffusion fluid flow sensor |
| EP0176996B1 (en) * | 1984-10-01 | 1991-06-05 | Honeywell Inc. | Semiconductor device, in particular semiconductor sensor and method for its fabrication |
| JPS6295454A (en) * | 1985-10-22 | 1987-05-01 | Nippon Telegr & Teleph Corp <Ntt> | Micro gas sensor and its production |
| JPS62159627U (en) * | 1986-03-31 | 1987-10-09 | ||
| JPH0257066U (en) * | 1988-10-18 | 1990-04-25 | ||
| JPH0795076B2 (en) * | 1989-05-23 | 1995-10-11 | 山武ハネウエル株式会社 | Flow velocity sensor |
| US6306496B1 (en) | 1997-12-11 | 2001-10-23 | Teijin Limited | Biaxially oriented polyester film |
| JP4866191B2 (en) * | 2006-09-25 | 2012-02-01 | シチズンホールディングス株式会社 | Gas sensor and manufacturing method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3359462A (en) * | 1964-08-04 | 1967-12-19 | Telefunken Patent | Electrical circuit device |
| JPS5389799A (en) * | 1977-01-18 | 1978-08-07 | Mitsubishi Electric Corp | Combustible gas detector |
| US4129848A (en) * | 1975-09-03 | 1978-12-12 | Raytheon Company | Platinum film resistor device |
-
1979
- 1979-07-25 JP JP9363779A patent/JPS5618381A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3359462A (en) * | 1964-08-04 | 1967-12-19 | Telefunken Patent | Electrical circuit device |
| US4129848A (en) * | 1975-09-03 | 1978-12-12 | Raytheon Company | Platinum film resistor device |
| JPS5389799A (en) * | 1977-01-18 | 1978-08-07 | Mitsubishi Electric Corp | Combustible gas detector |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01239102A (en) * | 1988-03-18 | 1989-09-25 | Mitsubishi Rayon Co Ltd | Disposable diaper |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5618381A (en) | 1981-02-21 |
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