JPH03233350A - Production of gas sensor - Google Patents
Production of gas sensorInfo
- Publication number
- JPH03233350A JPH03233350A JP2166294A JP16629490A JPH03233350A JP H03233350 A JPH03233350 A JP H03233350A JP 2166294 A JP2166294 A JP 2166294A JP 16629490 A JP16629490 A JP 16629490A JP H03233350 A JPH03233350 A JP H03233350A
- Authority
- JP
- Japan
- Prior art keywords
- insulating layer
- layer
- silicon substrate
- gas
- stage
- 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.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 17
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 47
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 47
- 239000010703 silicon Substances 0.000 claims abstract description 47
- 239000000758 substrate Substances 0.000 claims abstract description 38
- 238000000034 method Methods 0.000 claims abstract description 13
- 239000002184 metal Substances 0.000 claims description 16
- 229910052751 metal Inorganic materials 0.000 claims description 16
- 238000005530 etching Methods 0.000 abstract description 11
- 239000011248 coating agent Substances 0.000 abstract 1
- 238000000576 coating method Methods 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 56
- 239000010408 film Substances 0.000 description 8
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 7
- 229920005591 polysilicon Polymers 0.000 description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 229910052737 gold Inorganic materials 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000004065 semiconductor Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000005566 electron beam evaporation Methods 0.000 description 2
- 238000001259 photo etching Methods 0.000 description 2
- 238000000206 photolithography Methods 0.000 description 2
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 2
- 229910001887 tin oxide Inorganic materials 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000005468 ion implantation Methods 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 238000004518 low pressure chemical vapour deposition Methods 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明はＬＰガスや都市ガス等のガスもれ警報器等に
使用されるガスセンサの製造方法に係り、特に消費電力
の少ないガスセンサの容易な製造方法に関する。[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a method for manufacturing a gas sensor used in a gas leak alarm for LP gas, city gas, etc. Regarding the manufacturing method.
酸化スズ、酸化亜鉛等のｎ型金属酸化物半導体は、大気
中で３００〜５００℃の温度に加熱されると粒子表面に
大気中の酸素が活性化吸着して高抵抗化しているが、可
燃性ガスが接触すると吸着酸素と可燃性ガスとが反応し
て吸着酸素が除去され抵抗値が減少する。このような性
質を利用して、酸化スズを用いたガスセンサがＬＰガス
、都市ガス等のガス漏れ警報器に広く用いられている。When n-type metal oxide semiconductors such as tin oxide and zinc oxide are heated to a temperature of 300 to 500°C in the atmosphere, atmospheric oxygen is activated and adsorbed onto the particle surface, resulting in a high resistance, but they are not flammable. When a flammable gas comes into contact with the adsorbed oxygen, the adsorbed oxygen reacts with the combustible gas, the adsorbed oxygen is removed, and the resistance value decreases. Taking advantage of these properties, gas sensors using tin oxide are widely used in gas leak alarms for LP gas, city gas, and the like.
従来のガスセンサは例えば第９図に示すように基板ｌ、
電極５，６、感ガス層２Ａ、酸化層３＾、ヒータ４等か
ら構成されたものが用いられる。For example, as shown in FIG. 9, a conventional gas sensor has a substrate l,
A device composed of electrodes 5, 6, a gas-sensitive layer 2A, an oxide layer 3^, a heater 4, etc. is used.
このような従来のガスセンサは、熱容量が大きくて消費
電力が数１００− であり、また立上がり時間が長く
熱平衡に達するのに時間がかかりパルス駆動ができない
といった問題があり、システム機器内蔵型のガス警報器
、プロセスモニタを構成する上で大きな障害があった。Conventional gas sensors like this have a large heat capacity and power consumption of several 100 mm, and also have problems such as a long rise time and a long time to reach thermal equilibrium, making pulse drive impossible. There were major obstacles in configuring equipment and process monitors.
この問題を解決するために特開昭５９−１４３９４６号
公報に開示されているように、シリコンチップに５ｌｏ
ｚ絶縁層の張出部を設け、この張出部にヒータ。In order to solve this problem, as disclosed in Japanese Patent Application Laid-Open No. 59-143946, 5lo
zProvide an overhang of the insulating layer, and install a heater on this overhang.
電極、感ガス層を積層した超小型のガスセンサが知られ
るに至った。このガスセンサは半導体技術を用いて製造
されるが特に絶縁層の侵出部の製造にシリコンの異方性
エツチングを応用して絶縁層の下側に存在するシリコン
基板のアンダカットが行われる。このアンダカントに際
しては絶縁層がマスクとして用いられる。Ultra-compact gas sensors that have laminated electrodes and gas-sensitive layers have come to be known. This gas sensor is manufactured using semiconductor technology, and in particular, anisotropic etching of silicon is applied to manufacture the protruding portion of the insulating layer to undercut the silicon substrate existing under the insulating layer. The insulating layer is used as a mask during this undercanting.
〔発明が解決しようとするＩ’ｌｌ）
しかしながら上述のようなアンダカットにおいてはマス
クである絶縁層がシリコン基板のエツチングの間、常時
エンチング溶液にさらされ、少ないながらもエツチング
されそのために損傷を受けやすく良好な張出部が形成さ
れないという問題があった。 Ｓｉｎ、絶縁層は膜厚が
薄いからである。[To be solved by the invention] However, in the above-mentioned undercut, the insulating layer serving as a mask is constantly exposed to the etching solution during etching of the silicon substrate, and is etched and damaged as a result, albeit to a small extent. There was a problem in that a good overhang was not easily formed. This is because the film thickness of the Sin insulating layer is thin.
この発明は上述の点に鑑みてなされ、その目的は絶縁層
張出部の調製法に改良を加えることにより、消費電力の
少ない小型のガスセンサの容易な製造方法を提供するこ
とにある。The present invention has been made in view of the above-mentioned points, and its purpose is to provide an easy manufacturing method for a small gas sensor with low power consumption by improving the method for preparing the insulating layer overhang.
上述の目的はこの発明によれば、第１工程により切欠部
５０，５０Ａるを設けた第１のシリコン基板１１と絶縁
層２２を形成した第２のシリコン基板１２を融着させ、
第２のシリコン基板のシリコン層を除去して第１の絶縁
層２２からなる張出部を形成し、第２工程により前記張
出部の上に所定のパターンでヒータ層１３．１３Ａを形
成し、第３工程により、前記ヒータ層を被覆して第２の
絶縁層２４を形成し、第４工程により１対の金属電極３
１．３２を前記第２の絶縁層の上に形成し、第５工程に
より感ガス層４０を前記１対の電極上および前記第２の
絶縁層の上に選択的に形成することにより達成される。According to the present invention, the above-mentioned purpose is to fuse the first silicon substrate 11 provided with the notches 50, 50A and the second silicon substrate 12 provided with the insulating layer 22 in a first step;
The silicon layer of the second silicon substrate is removed to form an overhang made of the first insulating layer 22, and a heater layer 13.13A is formed in a predetermined pattern on the overhang in a second step. , a second insulating layer 24 is formed by covering the heater layer in a third step, and a pair of metal electrodes 3 is formed in a fourth step.
1.32 is formed on the second insulating layer, and in a fifth step, a gas-sensitive layer 40 is selectively formed on the pair of electrodes and on the second insulating layer. Ru.
シリコン層は選択的に除去されるのでなく、エンチング
で全面除去されののでシリコン除去後にエンチング溶液
が絶縁層と接触することとなり絶縁層とエツチング溶液
との接触時間が短くなる。Since the silicon layer is not selectively removed but is completely removed by etching, the etching solution comes into contact with the insulating layer after the silicon is removed, thereby shortening the contact time between the insulating layer and the etching solution.
次にこの発明の実施例を図面に基いて説明する。 Next, embodiments of the present invention will be described based on the drawings.
第１図はこの発明の実施例に係るガスセンサの平面図、
第２図はこの発明の実施例に係るガスセンサにつき、感
ガス層近傍の要部拡大平面図、第３図はこの発明の実施
例に係るガスセンサにつき、感ガス層近傍の要部拡大Ａ
−Ａ矢視断面図である。FIG. 1 is a plan view of a gas sensor according to an embodiment of the present invention;
FIG. 2 is an enlarged plan view of the main part near the gas-sensitive layer of the gas sensor according to the embodiment of the present invention, and FIG. 3 is an enlarged plan view of the main part near the gas-sensitive layer of the gas sensor according to the embodiment of the invention.
-A cross-sectional view.
シリコン基板１１は貫通孔５０を有し、Ｓｉｎｇである
第１の絶縁層２２がシリコン基板１１の主面が形成され
貫通孔５０に張出す、ポリシリコン層１３が第１の絶縁
層の上に選択的に形成され、その上に第２の絶縁層２４
がバンド３５．３６のための窓を形成してシリコン基板
の全面に設けられる。第２の絶縁層２４の上にはパッド
３５．３６と金属電極３１．３２とが設けられ、さらに
感ガス層４０が円形に形成される。金属電極３１．３２
、感ガス層４０は、シリコン基板１１の貫通孔５０に
張出した円形の第１の絶縁層２２の中心部分に位置する
。 ２１は酸化膜絶縁層である。ポリシリコン層１３は
ヒータであり、感ガス層４０のうちのヒータ直上の部分
を有効に加熱する。金属電極３１゜３２は感ガス層４０
の抵抗を検知する。ポリシリコン層１３はバンド３５．
３６の形成される部分を除いて、第１および第２の絶縁
層によってサンドウィンチされる。第１および第２の絶
縁層はＳｉｎｇであり、熱の不良導体で基板１１への熱
の伝導を防ぐ、バンド３５．３６と金属電極３１．３２
の所定部にリード線（図示せず）が接続される。主要部
の寸法は第１および第２の絶縁層２２．２４が厚さ約１
ｎ、ポリシリコン層１３は厚さ０．５４１１１１％最狭
部の幅２０−１金属電極３１．３２はＰｔまたはＡｕか
らなり厚さ０．１〜０．３−１最狭部の幅２０ａである
。感ガス層４０はＳｎＯ□Ｚｎ０ｘ等を主成分とする酸
化物半導体であり、厚さ０．１〜ＩＩｍである。シリコ
ン基板の貫通孔５０は直径１５０〜２５０μである。The silicon substrate 11 has a through hole 50, and a polysilicon layer 13 is formed on the first insulating layer 22 on which the main surface of the silicon substrate 11 is formed and extends into the through hole 50. A second insulating layer 24 is selectively formed thereon.
are provided over the entire surface of the silicon substrate forming windows for bands 35,36. Pads 35, 36 and metal electrodes 31, 32 are provided on the second insulating layer 24, and a gas-sensitive layer 40 is also formed in a circular shape. Metal electrode 31.32
The gas-sensitive layer 40 is located at the center of the circular first insulating layer 22 extending into the through hole 50 of the silicon substrate 11 . 21 is an oxide film insulating layer. The polysilicon layer 13 is a heater, and effectively heats the portion of the gas-sensitive layer 40 directly above the heater. The metal electrodes 31 and 32 are gas sensitive layers 40
Detects the resistance of Polysilicon layer 13 forms band 35.
The first and second insulating layers are sandwiched together, except where 36 is formed. The first and second insulating layers are a band 35.36 and a metal electrode 31.32, which are poor conductors of heat and prevent heat conduction to the substrate 11.
A lead wire (not shown) is connected to a predetermined portion of. The dimensions of the main part are such that the first and second insulating layers 22, 24 have a thickness of approximately 1 mm.
n, the polysilicon layer 13 has a thickness of 0.541111%, the width at the narrowest part 20-1, the metal electrode 31.32 is made of Pt or Au, and the thickness is 0.1 to 0.3-1, the width at the narrowest part 20a. be. The gas-sensitive layer 40 is an oxide semiconductor mainly composed of SnO□Zn0x and has a thickness of 0.1 to IIm. The through hole 50 in the silicon substrate has a diameter of 150 to 250 μm.
このようなガスセンサは以下の方法で製造することがで
きる。Such a gas sensor can be manufactured by the following method.
第４図はこの発明の実施例に係るガスセンサの製造手順
を示す工程図である。厚さ０．１〜０．８鶴のシリコン
基板１１にＹＡＧレーザを用いて貫通孔５０が設けられ
る。同様なシリコン基板１２と前記貫通孔を有するシリ
コン基板１１は水蒸気酸化法で絶縁層２１，２２．２３
を形成する。水蒸気酸化は１１００℃で行われ、時間に
より膜厚が制御される。酸化処理されたシリコン１Ｆ１
．１１．１２は第４図（ａｌに示すように重合され、９
００℃で１ｈ加熱し融着される。つづいて、酸化膜２３
をフン酸を用いてエンチング除去し、シリコンウェハ１
２の部分もＨＰ ： ＨＮＯｉ ： ［０−１：１：１
の溶液を用いてエツチング除去される （第４図中）参
照）。FIG. 4 is a process diagram showing the manufacturing procedure of a gas sensor according to an embodiment of the present invention. A through hole 50 is provided in a silicon substrate 11 having a thickness of 0.1 to 0.8 mm using a YAG laser. A similar silicon substrate 12 and the silicon substrate 11 having the through holes are formed using a steam oxidation method to form insulating layers 21, 22, and 23.
form. Steam oxidation is performed at 1100°C, and the film thickness is controlled by time. Oxidized silicon 1F1
．． 11.12 was polymerized as shown in Figure 4 (al) and 9
It is heated and fused at 00°C for 1 hour. Next, the oxide film 23
was removed by etching using hydrochloric acid, and silicon wafer 1
Part 2 is also HP: HNOi: [0-1:1:1
(See Figure 4).
第１の絶縁層２２の上にポリシリコン層１３が減圧ＣＶ
Ｄ法で形成される。ポリシリコン層１３にはイオンイン
プランチーシランによりＢが１０目〜１０１０ｌ９ａ’
濃度に打ちこまれ、所定抵抗値を示すヒータが得られる
。このあとホトエンチングにより、所定のパターンに加
工される （第４図（Ｑ）参照）。A polysilicon layer 13 is formed on the first insulating layer 22 by applying low pressure CVD.
Formed by method D. In the polysilicon layer 13, B is added at 10 to 1010l9a' by ion implantation silane.
A heater having a predetermined resistance value is obtained. Thereafter, it is processed into a predetermined pattern by photo-etching (see Figure 4 (Q)).
ポリシリコン層１３の上には第２の絶縁層であるＳｉＯ
ｇｗＡ縁層２４がプラズマＣＶＤ法で形成される（第４
図ｆｄ）参照）
第２の絶縁層２４の上にｐｔあるいはＡｕが電子ビーム
蒸着され、続いてホトリソグラフィーにより金属電極３
１．３２ 、バンド３５．３６が形成される （第４図
（１１１参照）。On the polysilicon layer 13 is a second insulating layer of SiO.
gwA edge layer 24 is formed by plasma CVD method (fourth
(See Figure fd)) PT or Au is electron beam-deposited on the second insulating layer 24, and then the metal electrode 3 is formed by photolithography.
1.32, bands 35 and 36 are formed (Fig. 4 (see 111)).
感ガス層４０がＳｎＪを用いて電子ビーム蒸着法により
成膜される。感ガス層は選択マスクを用いて直接的に形
成される。A gas-sensitive layer 40 is formed using SnJ by electron beam evaporation. The gas-sensitive layer is formed directly using a selective mask.
このようにして３朝角のシリコン基板を有するガスセン
サが得られる。消費電力１０ｍ−で感ガス層の温度が４
００℃に達する。この発明によれば小型センサが容易に
得られ、製造歩留りは９０％に達する。またこの発明の
製造方法によるときは、特定の結晶方位のシリコン基板
を必要とせず、また絶縁層の張出部の形成に特定のマス
クを必要とせず、製造コストが安価になるという効果も
得られる。In this way, a gas sensor having a three-sided silicon substrate is obtained. The temperature of the gas-sensitive layer is 4 when the power consumption is 10m-
It reaches 00℃. According to this invention, a small sensor can be easily obtained, and the manufacturing yield reaches 90%. Furthermore, when using the manufacturing method of the present invention, a silicon substrate with a specific crystal orientation is not required, and a specific mask is not required for forming the overhanging portion of the insulating layer, resulting in lower manufacturing costs. It will be done.
第５図ないし第８図は本発明の異なる実施例を示し、第
５図はガスセンサの平面図、第６図は感ガス層近傍の要
部拡大平面図、第７図は感ガス層近傍の要部拡大Ａ−Ａ
矢視断面図である。5 to 8 show different embodiments of the present invention, FIG. 5 is a plan view of the gas sensor, FIG. 6 is an enlarged plan view of the main part near the gas-sensitive layer, and FIG. 7 is a plan view of the main part near the gas-sensitive layer. Main part enlarged A-A
It is an arrow sectional view.
シリコン基板１１は溝部５０Ａを有し、ＳｉＪである１
の絶縁層２２がシリコン基板１１の主面が形成され溝部
５０Ａに張出す、ヒータ層１３Ａが第１の絶縁層の上に
選択的に形成され、その上に第２の絶縁層２４がバンド
３５．３６のための窓を形成してシリコン基板の全面に
設けられる。第２の絶縁層２４の上にはパッド３５．３
６と金属電極３１．３２とが設けられ、さらに感ガス層
４０が円形に形成される。金属電極３１．３２ 、感ガ
ス層４０は、シリコン基板１１の溝部５０Ａに張出した
円形の第１の絶縁層２２の中心部分に位置する。２１は
酸化膜絶縁層である。ヒータ層１３＾は、感ガス層４０
のうちのヒータ直上の部分を有効に加熱する。金属電極
３１．３２は感ガス層４０の抵抗を検知する。ヒータ層
１３Ａはパッド３５ 、３６の形成される部分を除いて
、第１および第２の絶縁層によってサンドウィッチされ
る。第１および第２の絶縁層はＳｉｎｇであり、熱の不
良導体で基板１１への熱の伝導を防ぐ、パッド３５．３
６と金属電極３１．３２の所定部にリードｍ（図示せず
）が接続される。The silicon substrate 11 has a groove 50A and is made of SiJ.
An insulating layer 22 is formed on the main surface of the silicon substrate 11 and extends into the groove 50A. A heater layer 13A is selectively formed on the first insulating layer, and a second insulating layer 24 is formed on the first insulating layer 24. .36 is formed on the entire surface of the silicon substrate. On the second insulating layer 24 is a pad 35.3.
6 and metal electrodes 31, 32 are provided, and further a gas sensitive layer 40 is formed in a circular shape. The metal electrodes 31, 32 and the gas-sensitive layer 40 are located at the center of the circular first insulating layer 22 extending into the groove 50A of the silicon substrate 11. 21 is an oxide film insulating layer. The heater layer 13^ is the gas sensitive layer 40
Effectively heats the part directly above the heater. Metal electrodes 31 , 32 sense the resistance of gas sensitive layer 40 . The heater layer 13A is sandwiched between the first and second insulating layers except for the portions where the pads 35 and 36 are formed. The first and second insulating layers are pads 35.3, which are poor conductors of heat and prevent heat conduction to the substrate 11.
A lead m (not shown) is connected to a predetermined portion of the metal electrode 6 and the metal electrode 31, 32.
主要部の寸法は第１および第２の絶縁層２２．２４が厚
さ約１ｎ１ヒータ層１３Ａは厚さ０．２−１最狭部の幅
１０μ、金属電極３１．３２はｐｔまたはＡｕからなり
厚さ０．１〜０．３μ、最狭部の幅１０μである。感ガ
ス層４０はＳｎｕｇ、 Ｚｎ０ｇ等を主成分とする酸化
物半導体であり、厚さ０．１〜１μである。シリコン基
板の溝部５０＾の溝幅は１５０〜２５０−で、深さは５
０μである。The dimensions of the main parts are that the first and second insulating layers 22, 24 have a thickness of about 1n1, the heater layer 13A has a thickness of 0.2-1, the width at the narrowest part is 10μ, and the metal electrodes 31, 32 are made of PT or Au. The thickness is 0.1 to 0.3μ, and the width at the narrowest part is 10μ. The gas-sensitive layer 40 is an oxide semiconductor mainly composed of Snug, Zn0g, etc., and has a thickness of 0.1 to 1 μm. The groove width of the groove 50^ of the silicon substrate is 150 to 250 -, and the depth is 5
It is 0μ.
このようなガスセンサは以下の方法で製造することがで
きる。Such a gas sensor can be manufactured by the following method.
第８図はこの発明の異なる実施例に係るガスセンサの製
造手順を示す工程図である。厚さ０．３〜０．８ ｍの
シリコン基板１１に選択エツチング技術を用いて溝部５
０Ａが設けられる。同様なシリコン基板１２と前記溝部
を有するシリコン基板１１は水蒸気酸化法で絶縁層２
１．２２．２３を形成する。水蒸気酸化は１１００℃で
行われ、時間により膜厚が制御される。酸化処理された
シリコン基板１１．１２は第８図（ａ）に示すように重
ね合され、９００℃で１ｈ加熱し融着される。つづいて
、酸化膜２３をフン酸を用いてエツチング除去し、シリ
コンウェハ１２の部分もＩＰ ： ＨＮＯ３： ＨｔＯ
社１：１：１の溶液を用いてエツチング除去される （
第８図中）参照）。FIG. 8 is a process diagram showing the manufacturing procedure of a gas sensor according to a different embodiment of the present invention. Grooves 5 are formed in a silicon substrate 11 with a thickness of 0.3 to 0.8 m using a selective etching technique.
0A is provided. A similar silicon substrate 12 and a silicon substrate 11 having the grooves are formed into an insulating layer 2 by steam oxidation.
Form 1.22.23. Steam oxidation is performed at 1100°C, and the film thickness is controlled by time. The oxidized silicon substrates 11 and 12 are stacked on top of each other as shown in FIG. 8(a), and heated and fused at 900° C. for 1 hour. Subsequently, the oxide film 23 is removed by etching using hydronic acid, and the silicon wafer 12 is also subjected to IP: HNO3: HtO.
Etched away using a 1:1:1 solution (
(See Figure 8).
第１の絶縁層２２の上にヒータ層１３Ａが形成される。A heater layer 13A is formed on the first insulating layer 22.
ヒータ層は、蒸着法あるいはスパッタリング法により、
ＰｔあるいはＮｉの薄膜を形成し、このあと、ホトエン
チング技術を用いてパターン加工して所定の抵抗値をも
つヒータが得られる （第８図ＦＣ＋参照）。The heater layer is formed by vapor deposition or sputtering.
A thin film of Pt or Ni is formed and then patterned using photo-etching technology to obtain a heater with a predetermined resistance value (see FIG. 8, FC+).
ヒータ層１３Ａの上には第２の絶縁層であるＳｉＪ絶縁
層２４がプラズマＣＶＤ法で形成される （第８図ｆｄ
＋参照〉。A SiJ insulating layer 24, which is a second insulating layer, is formed on the heater layer 13A by a plasma CVD method (FIG. 8 fd
+Reference>.
第２の絶縁層２４の上にｐｔあるいはＡｕが電子ビーム
蒸着され、続いてホトリソグラフィーにより金属電極３
１，３２ 、パッド３５．３６が形成される （第８図
（Ｑ）参照）。PT or Au is electron beam evaporated onto the second insulating layer 24, and then the metal electrode 3 is formed by photolithography.
1, 32, and pads 35 and 36 are formed (see FIG. 8(Q)).
感ガス層４０がＳｎＯオを用いて電子ビーム蒸着法によ
りｔｃ膜される。感ガス層は選択マスクを用いて直接的
に形成される。The gas-sensitive layer 40 is formed into a TC film using SnO by electron beam evaporation. The gas-sensitive layer is formed directly using a selective mask.
このようにして３鵡角のシリコン基板を有するガスセン
サが得られる。消費電力１０ｍＷで感ガス層の温度が４
００℃に達する。この発明によれば小型センサが容易に
得られ、製造歩留りは９０％に達する。またこの発明の
製造方法によるときは、特定の結晶方位のシリコン基板
を必要とせず、また絶縁層の張出部の形成に特定のマス
クを必要とせず、製造コストが安価になるという効果も
得られる。In this way, a gas sensor having a 3-square silicon substrate is obtained. The temperature of the gas-sensitive layer is 4 with power consumption of 10 mW.
It reaches 00℃. According to this invention, a small sensor can be easily obtained, and the manufacturing yield reaches 90%. Furthermore, when using the manufacturing method of the present invention, a silicon substrate with a specific crystal orientation is not required, and a specific mask is not required for forming the overhanging portion of the insulating layer, resulting in lower manufacturing costs. It will be done.
この発明によれば、第１工程により切欠部を設けた第１
のシリコン基板と絶縁層を形成したＩｎ２のシリコン基
板を融着させ、第２のシリコン基板のシリコン層を除去
して第１の絶縁層からなる張出部を形成し、第２工程に
より前記張出部の上に所定のパターンでヒータ層を形成
し、第３工程により、前記ヒータ層を被覆して第２の絶
縁層を形成し、第４工程により１対の金属電極を前記第
２の絶縁層の上に形成し、第５工程により感ガス層４０
を前記１対の電極上および前記第２の絶縁層の上に選択
的に形成するのでシリコン層の全面除去により絶縁層の
張出部が形成されることとなりそのために絶縁層がエツ
チング溶液と接触する時間が短く絶縁層張出部の損傷が
なくなって消費電力の少ない小型センサの製造が容易に
なる。According to this invention, the first
A silicon substrate made of In2 and an In2 silicon substrate on which an insulating layer has been formed are fused together, the silicon layer of the second silicon substrate is removed to form an overhang made of the first insulating layer, and a second step A heater layer is formed in a predetermined pattern on the protruding portion, a second insulating layer is formed by covering the heater layer in a third step, and a pair of metal electrodes are attached to the second insulating layer in a fourth step. A gas-sensitive layer 40 is formed on the insulating layer in a fifth step.
is selectively formed on the pair of electrodes and the second insulating layer, so that an overhang of the insulating layer is formed by removing the entire silicon layer, so that the insulating layer comes into contact with the etching solution. This reduces the time it takes to do this, eliminates damage to the insulating layer overhang, and facilitates the manufacture of small sensors with low power consumption.
第１図はこの発明の実施例に係るガスセンサを示す平面
図、第２図はこの発明の実施例に係るガスセンサの要部
拡大平面図、第３図はこの発明の実施例に係るガスセン
サの要部拡大Ａ−Ａ矢視断面図、第４図ｆａｌ〜（８）
はそれぞれこの発明の実施例に係るガスセンサの製造手
順を示す工程図、第５図ないし第８図はそれぞれ本発明
の異なる実施例を示し、第５図はガスセンサを示す平面
図、第６図はガスセンサの要部拡大平面図、第７図はガ
スセンサの要部拡大Ａ−Ａ矢視断面図、第８図（ａｔ〜
（ｅｌはそれぞれガスセンサの製造手順を示す工程図、
第９図は従来のガスセンサを示す断面図である。FIG. 1 is a plan view showing a gas sensor according to an embodiment of the invention, FIG. 2 is an enlarged plan view of main parts of a gas sensor according to an embodiment of the invention, and FIG. 3 is a main part of a gas sensor according to an embodiment of the invention. Enlarged section A-A cross-sectional view, Figure 4 fal ~ (8)
5 to 8 each show different embodiments of the invention, FIG. 5 is a plan view showing the gas sensor, and FIG. FIG. 7 is an enlarged plan view of the main part of the gas sensor, and FIG.
(el is a process diagram showing the manufacturing procedure of the gas sensor,
FIG. 9 is a sectional view showing a conventional gas sensor.
Claims (1)
した第２のシリコン基板を融着させ、第２のシリコン基
板のシリコン層を除去して第１の絶縁層からなる張出部
を形成する第１工程と、前記張出部の上に所定のパター
ンでヒータ層を形成する第２工程と、前記ヒータ層を被
覆して第２の絶縁層を形成する第３工程と、１対の金属
電極を前記第２の絶縁層の上に形成する第４工程と、感
ガス層を前記１対の電極上および前記第２の絶縁層の上
に選択的に形成する第５工程からなることを特徴とする
ガスセンサの製造方法。1) A first silicon substrate with a cutout and a second silicon substrate with an insulating layer formed thereon are fused together, and the silicon layer of the second silicon substrate is removed to form an overhang made of the first insulating layer. a second step of forming a heater layer in a predetermined pattern on the overhang, and a third step of forming a second insulating layer by covering the heater layer; a fourth step of forming a pair of metal electrodes on the second insulating layer; and a fifth step of selectively forming a gas-sensitive layer on the pair of electrodes and the second insulating layer; A method for manufacturing a gas sensor, characterized in that:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2166294A JP3033143B2 (en) | 1989-12-28 | 1990-06-25 | Gas sensor manufacturing method |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34350389 | 1989-12-28 | ||
| JP1-343503 | 1989-12-28 | ||
| JP2166294A JP3033143B2 (en) | 1989-12-28 | 1990-06-25 | Gas sensor manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03233350A true JPH03233350A (en) | 1991-10-17 |
| JP3033143B2 JP3033143B2 (en) | 2000-04-17 |
Family
ID=26490723
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2166294A Expired - Fee Related JP3033143B2 (en) | 1989-12-28 | 1990-06-25 | Gas sensor manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3033143B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0684604A (en) * | 1991-09-19 | 1994-03-25 | Mitsuteru Kimura | Microheater |
| JP2002323467A (en) * | 2001-04-25 | 2002-11-08 | Denso Corp | Thin-film gas sensor and method of manufacturing the same |
| JP2006024937A (en) * | 1995-11-30 | 2006-01-26 | Freescale Semiconductor Inc | Semiconductor heater and its manufacturing method |
| JP2014173947A (en) * | 2013-03-07 | 2014-09-22 | Fuji Electric Co Ltd | Porous structure, method for producing porous structure, and gas sensor |
| JP2014173946A (en) * | 2013-03-07 | 2014-09-22 | Fuji Electric Co Ltd | Gas sensor |
-
1990
- 1990-06-25 JP JP2166294A patent/JP3033143B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0684604A (en) * | 1991-09-19 | 1994-03-25 | Mitsuteru Kimura | Microheater |
| JP2006024937A (en) * | 1995-11-30 | 2006-01-26 | Freescale Semiconductor Inc | Semiconductor heater and its manufacturing method |
| JP2002323467A (en) * | 2001-04-25 | 2002-11-08 | Denso Corp | Thin-film gas sensor and method of manufacturing the same |
| JP2014173947A (en) * | 2013-03-07 | 2014-09-22 | Fuji Electric Co Ltd | Porous structure, method for producing porous structure, and gas sensor |
| JP2014173946A (en) * | 2013-03-07 | 2014-09-22 | Fuji Electric Co Ltd | Gas sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3033143B2 (en) | 2000-04-17 |
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