EP0671629A2
Expired / Lapsed
EP
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Semiconductor acceleration sensor and manufacturing method thereof
Assignee: Denso Corp
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Filing: 1995-03-07
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Granted: —
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Expires: 2015-03-07
Abstract
Abstract A semiconductor acceleration sensor capable of reducing a leakage current and manufacturing method thereof is disclosed. A beam structure (64) is disposed on a silicon substrate (1). Beam structure has a movable section, and movable section (9) is disposed spaced at a prescribed distance above silicon substrate. A movable electrode section is formed in one portion of movable section (10,11). Fixed electrodes (17) made of an impurity diffusion layer are formed in silicon substrate to correspond to both sides of a movable electrode section. A peripheral circuit (20) is formed in silicon substrate. Beam structure and peripheral circuit are electrically connected by an electroconductive thin film, made of polysilicon. Then, when a voltage is applied to beam structure, and a voltage is applied to both fixed electrodes, an inversion layer is formed, and an electrical current flows between the fixed electrodes. In the case where an acceleration is received and movable section is displaced, the electrical current flowing between the fixed electrodes changes.
Inventors
- 👤 Hirofumi Uenoyama
- 👤 Kenichi Ao
- 👤 Masakazu Kanosue
- 👤 Yasutoshi Suzuki
- 👤 Yukihiro Takeuchi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 17:11
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/0802; G01P15/12; Y; Y10; Y10S; Y10S73/00; Y10S73/01
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
79 words
A semiconductor acceleration sensor comprising: a semiconductor substrate; a beam structure having a movable section disposed spaced at a predetermined distance above said semiconductor substrate; a peripheral circuit formed in said semiconductor substrate, electrically connected to said beam structure, whereby an applied acceleration is detected from a displacement of a movable section; and a connection member, for electrically connecting said beam structure and said peripheral circuit, consisting of at least one electroconductive thin film formed above said semiconductor substrate.
Claim 2
Dependent Claim
33 words
A semiconductor acceleration sensor as set forth in claim 1, wherein said electroconductive thin film is of the same material as a gate electrode of a MOS transistor formed in a peripheral circuit.
Claim 3
Dependent Claim
24 words
A semiconductor acceleration sensor as set forth in claim 1, wherein said electroconductive thin film is a wiring film extended from said peripheral circuit.
Claim 4
Dependent Claim
56 words
A semiconductor acceleration sensor as set forth in claim 3, wherein said beam structure has a connection portion with a thin thickness in comparison with the other portion thereof, said connection portion being disposed on an insulation film, and wherein, on top of said connection portion, a wiring film extended from said peripheral circuit is disposed.
Claim 5
Independent Claim
141 words
A method of manufacturing a semiconductor acceleration sensor comprising the steps of: forming an insulation film on a semiconductor substrate and forming a beam structure formation film on said insulation film; thinning said beam structure formation film down to a predetermined film thickness exclusive of a region where a movable section of a beam structure is located; removing said beam structure formation film except a region for said beam structure, whereby a connection region of said beam structure becomes thin as compared with said movable section in thickness thereof; forming a wiring film electrically connecting said connection region of said beam structure to a peripheral circuit formed in said semiconductor substrate; and removing said insulation film located under said movable section of said beam structure, whereby said movable section of said beam structure becomes displacable with respect to said semiconductor substrate.
Claim 6
Dependent Claim
122 words
A semiconductor acceleration sensor comprising: a semiconductor substrate; a beam structure having a movable section disposed spaced at a predetermined distance above said semiconductor substrate, one portion of said movable section being a movable electrode section; a pair of fixed electrodes, each being of an impurity diffusion layer formed in said semiconductor substrate, located so as to correspond to said movable electrode section; an underlying electrode for making an electrostatic force occurring between said semiconductor substrate and said movable section small, formed in said semiconductor substrate so as to oppose said movable section and be spaced from said fixed electrodes; and a leakage current prevention member disposed at a region corresponding to a region between said fixed electrodes and said underlying electrode.
Claim 7
Dependent Claim
127 words
A semiconductor acceleration sensor comprising: a semiconductor substrate; a beam structure having a movable section disposed spaced at a predetermined distance above said semiconductor substrate, one portion of said movable section being a movable electrode section; a pair of fixed electrodes, each being of an impurity diffusion layer formed in said semiconductor substrate, located so as to correspond to said movable electrode section; and an underlying electrode for making an electrostatic force occurring between said semiconductor substrate and said movable section small, formed in said semiconductor substrate so as to oppose said movable section and be spaced from said fixed electrodes, wherein an actual width of said movable electrode section is narrowed at a corresponding region which is located between said fixed electrodes and said underlying electrode.
Claim 8
Dependent Claim
33 words
A semiconductor acceleration sensor as set forth in claim 7, wherein said actual width of said movable electrode section is narrowed by cutting sections provided in both sides of said movable electrode section.
Claim 9
Dependent Claim
31 words
A semiconductor acceleration sensor as set forth in claim 7, wherein said actual width of said movable electrode section is narrowed by a penetrating hole provided in said movable electrode section.
Claim 10
Dependent Claim
76 words
A semiconductor acceleration sensor which detects an acceleration from a displacement in a movable section, comprising: a semiconductor substrate; a beam structure having a movable section disposed spaced at a predetermined distance above said semiconductor substrate; a peripheral circuit formed in said semiconductor substrate; and an electroconductive material extended from said peripheral circuit and electrically connected said peripheral circuit and said beam structure, wherein said beam structure is electrically connected on top of said electroconductive material.
Claim 11
Dependent Claim
23 words
A semiconductor acceleration sensor according to claim 10, wherein said electroconductive material is exposed in a connection portion connected to said beam structure.
Claim 12
Dependent Claim
30 words
A semiconductor acceleration sensor according to claim 10, wherein said electroconductive material is of the same material as a gate electrode of a MOS transistor formed in said peripheral circuit.
Claim 13
Dependent Claim
29 words
A semiconductor acceleration sensor according to claim 10, wherein said electroconductive material is selected from a group consisting of polysilicon, aluminum, platinum, titanium, tungsten, chrome silicon, zirconium and nickel.
Claim 14
Dependent Claim
92 words
A semiconductor acceleration sensor which detects an acceleration from a displacement in a movable section, comprising: a semiconductor substrate; a beam structure having a movable section disposed spaced at a predetermined distance above said semiconductor substrate, said beam structure having a thinned portion in thickness; a peripheral circuit formed in said semiconductor substrate; and an electroconductive material extended from said peripheral circuit for electrically connecting said peripheral circuit and said beam structure, wherein said electroconductive material is extended on top of and electrically connected to said thinned portion of said beam structure.
Claim 15
Dependent Claim
28 words
A semiconductor acceleration sensor according to claim 14, wherein said electroconductive material and said thinned portion of said beam structure are disposed on top of an insulation film.
Claim 16
Dependent Claim
23 words
A semiconductor acceleration sensor according to claim 14, wherein said electroconductive material is of an aluminum-based metal wiring formed in said peripheral circuit.
Claim 17
Dependent Claim
159 words
A semiconductor acceleration sensor which detects an acceleration from a displacement in a movable section, comprising: a semiconductor substrate; a beam structure having a movable section disposed spaced at a predetermined distance above said semiconductor substrate, one portion of said movable section being a movable electrode section; a pair of fixed electrodes of impurity diffusion layers formed in said semiconductor substrate, located so as to correspond to said movable electrode section; an underlying electrode of impurity diffusion layer located in said semiconductor substrate so as to oppose said movable section and be spaced from said fixed electrodes, said underlying electrode being applied an electrical potential equal to an electrical potential of said movable section, whereby a parasitic transistor is formed from said underlying electrode, said fixed electrode, and said movable section; leakage current prevention means for reducing a current flowing through a channel of said parasitic transistor, said channel being formed between said fixed electrode and said underlying electrode.
Claim 18
Dependent Claim
38 words
A semiconductor acceleration sensor according to claim 17, wherein said leakage current prevention means is an insulation body disposed between said fixed electrodes and said underlying electrode, both of which are in the surface of said semiconductor substrate.
Claim 19
Dependent Claim
134 words
A semiconductor acceleration sensor which detects an acceleration from a displacement in a movable section, comprising: a semiconductor substrate; a beam structure having a movable section disposed spaced at a predetermined distance above said semiconductor substrate, one portion of said movable section being a movable electrode section; a pair of fixed electrodes, each being of an impurity diffusion layer formed in said semiconductor substrate corresponding to both sides of said movable electrode section; and an underlying electrode of an impurity diffusion layer located in said semiconductor substrate facing a movable section and spaced from said fixed electrodes, said underlying electrode being applied with an electrical potential equal to an electrical potential of said movable section, wherein an actual width of said movable electrode section between said fixed electrodes and said underlying electrode is narrowed.
Claim 20
Dependent Claim
39 words
A semiconductor acceleration sensor according to claim 19, wherein said actual width of said movable electrode section is narrowed by means of a cut portion of said movable electrode section provided between said fixed electrodes and said underlying electrode.
References Cited (Backward Citations)
No citation records indexed.
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