EP0150827A2
Expired / Lapsed
EP
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Method of making silicon diaphragm pressure sensor
Assignee: Hitachi Ltd
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Filing: 1985-01-25
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Granted: —
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Expires: 2005-01-25
Abstract
Abstract A method of making a silicon diaphragm pressure sensor Includes forming an oxide film (10) on one surface of a monocrystalline silicon substrate (9). A polycrystalline silicon layer (11) is formed on the oxide film. The oxide film may be partly removed before the formation of the polycrystalline silicon layer. The polycrystalline silicon layer is heated and melt to recrystallize the same, thereby converting the polycrystalline silicon layer into a monocrystalline silicon layer. On the monocrystalline silicon layer may be epitaxially grown an additional monocrystalline silicon layer. By using the oxide film as an etching stopper, a predetermined portion of the substrate is etched over a range from the other surface of the substrate to the oxide film, thereby providing a diaphragm (12) of the pressure sensor.
Inventors
- 👤 Kazuji Yamada
- 👤 Yutaka Kobayashi
- 👤 Kanji Kawakami
- 👤 Satoshi Shimada
- 👤 Masanori Tanabe
- 👤 Shigeyuki Kobori
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 09:32
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0042; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/0802; G01P2015/0805; G01P2015/0822; G01P2015/084; Y; Y10; Y10S; Y10S148/00; Y10S148/012; Y10S148/159; Y10S148/168; Y10T; Y10T29/00; Y10T29/42; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49103
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
125 words
A method of making a silicon diaphragm pressure sensor comprising: a first step of preparing a monocrystalline silicon substrate (9) having first and second major surfaces and forming an oxide film (10) of a predetermined thickness on the first major surface; a second step of forming a polycrystalline silicon layer (11) on said oxide film; a third step of converting said polycrystalline silicon layer into a monocrystalline silicon layer (11) by heating and melting said polycrystalline silicon layer to recrystallize the same; and a fourth step of etching a predetermined portion (16) of said substrate over a range from the second major surface of said substrate by means of said oxide film as an etching stopper, thereby providing a diaphragm (12) of the pressure sensor.
Claim 2
Independent Claim
125 words
A method of making a silicon diaphragm pressure sensor comprising: a first step of preparing a monocrystalline silicon substrate (9) having first and second major surfaces and forming an oxide film (10) of a predetermined thickness on the first major surface; a second step of forming a polycrystalline silicon layer (11) on said oxide film; a third step of converting said polycrystalline silicon layer into a monocrystalline silicon layer (11) by heating and melting said polycrystalline silicon layer to recrystallize the same; and a fourth step of etching a predetermined portion (16) of said substrate over a range from the second major surface of said substrate by means of said oxide film as an etching stopper, thereby providing a diaphragm (12) of the pressure sensor.
Claim 3
Dependent Claim
28 words
A method according to Claim 1 further comprising, after said third step, a step of epitaxially growing an additional monocrystalline silicon layer (11') on said monocrystalline silicon layer.
Claim 4
Dependent Claim
32 words
A method according to Claim 1 further comprising, between said first and second steps, a step of partly removing said oxide film to partially expose the first major surface of said substrate.
Claim 5
Dependent Claim
28 words
A method according to Claim 3 further comprising, after said third step, a step of epitaxially growing an additional monocrystalline silicon layer (11') on said monocrystalline silicon layer.
Claim 6
Dependent Claim
59 words
A method according to Claim 1 further comprising, after said third step, a step of selectively diffusing an impurity of an opposite conductivity type to that of said monocrystalline silicon layer from the surface of said monocrystalline silicon layer to form therein a diffused region (13) of a predetermined pattern which serves as a piezo-resistor of the pressure sensor.
Claim 7
Dependent Claim
56 words
A method according to Claim 2 further comprising, a step of selectively diffusing an impurity of an opposite conductivity type to that of said additional monocrystalline silicon layer from the surface of said additional monocrystalline silicon layer to form therein a diffused region of a predetermined pattern which serves as a piezo-resistor of the pressure sensor.
Claim 8
Dependent Claim
59 words
A method according to Claim 3 further comprising, after said third step, a step of selectively diffusing an impurity of an opposite conductivity type to that of said monocrystalline silicon layer from the surface of said monocrystalline silicon layer to form therein a diffused region (13) of a predetermined pattern which serves as a piezo-resistor of the pressure sensor.
Claim 9
Dependent Claim
43 words
A method according to Claim 1 further comprising, between said third and fourth steps, a step of selectively removing said monocrystalline silicon layer to leave behind a portion thereof of a predetermined pattern which is used as a piezo-resistor of the pressure sensor.
References Cited (Backward Citations)
No citation records indexed.
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