Nippondenso Co., Ltd.

Denso Corporation

Masakazu Kanosue

Kenichi Ao

Yukihiro Takeuchi

Hirofumi Uenoyama

Takamoto Watanabe

Yasutoshi Suzuki

Kazuhiko Kano

Tsuyoshi Fukada

Minoru Murata

Minekazu Sakai

Inao Toyoda

Hiroshi Okada

Toshio Yamamoto

Seiichiro Ishio

Seiki Aoyama

Shinji Yoshihara

Kazushi Asami

Seiji Fujino

Hiroshi Muto

Kenichi Yokoyama

Hiroshige Sugito

Masakazu Terada

Koki Mizuno

Shoji Ozoe

Kenichi Nara

In a method for manufacturing a semiconductor acceleration sensor, a movable portion including a mass portion and movable electrodes is formed in a single crystal silicon thin film provided on a silicon wafer through an insulation film by etching both the single crystal silicon thin film and the silicon wafer. In this case, the movable portion is finally defined at a movable portion defining step that is carried out in a vapor phase atmosphere. Accordingly, the movable portion is prevented from sticking to other regions due to etchant during the manufacture thereof.

Method for manufacturing semiconductor dynamic quantity sensor

A semiconductor sensor has gauge resistors. The gauge resistors connect with aluminum electrodes through contact holes, and form a bridge circuit. The gauge resistors are formed on each chip area of a semiconductor substrate before dicing the chip areas. Then, the resistances of the gauge resistors or the output of the bridge circuit are measured. Contact positions of the gauge resistors or the size and/or shape of the contact holes are adjusted based on the result of the measurement in order to adjust the offset voltage of the bridge circuit formed on each chip area.

Method for fabrication of a semiconductor sensor

A semiconductor sensor including a movable member beam structure having a reduced deflection characteristic. The sensor includes a movable beam structure film suspended from a semiconductor substrate, with a gap interposed between the beam structure film and the substrate. The beam structure film is composed of a plurality of film layers that are laminated in a direction of film thickness. Further, a stress relieving layer is interposed between respective films to reduce overall internal stress on the structure.

Semiconductor sensor having multi-layer movable beam structure film

It is an object to provide a method of fabrication for a semiconductor acceleration sensor which can prevent destruction of a movable portion during dicing. A sacrificial layer composed of silicon oxide film is formed on a silicon substrate, and a movable member composed of polycrystalline silicon is formed on the sacrificial layer. A polyimide film is applied on the movable member at room temperature and heated to approximately 350.degree. C. to harden. The movable member is supported by this polyimide film. Accordingly, etching liquid penetration holes are formed on the polyimide film. Further, the sacrificial layer disposed between the movable member and the silicon substrate is etched away by means of dipping the silicon substrate into hydrofluoric acid-based etching liquid. Thereafter, the silicon substrate is dipped into demineralized water to replace the etching liquid with demineralized water, and subsequently the silicon substrate is dried. Accordingly, the silicon substrate is diced and thereafter the polyimide film is etched away by O.sub.2 ashing.

Method for fabricating a semiconductor acceleration sensor

A pair of signal voltages outputted from a bridge circuit composed of plural strain gauges are linearly amplified individually by a pair of amplifiers, whereupon a difference between the pair of signal voltages is detected. The pair of amplifiers are formed respectively in regions that are symmetrical with each other on a chip. As a result, variations in the output characteristics between the amplifiers are decreased.

Semiconductor sensor with a built-in amplification circuit

A semiconductor acceleration sensor according to the present invention performs acceleration detection by means of detecting increase or decrease in electrical current flowing between fixed electrodes formed on a semiconductor substrate taking a movable section in a movable state supported on the semiconductor substrate as a gate electrode. Two transistor structures are utilized in this detection. Current between fixed electrodes in one transistor structure increases when the movable section is subjected to acceleration and is displaced. At that time, current between fixed electrodes in the other transistor structure decreases. These two transistor structures are disposed proximately. By means of this proximate disposition, fluctuations in characteristics of both transistors are reduced, and by means of acceleration detection by differential type, temperature characteristics of the two transistors can be canceled favorably.

Semiconductor acceleration sensor with source and drain regions

A semiconductor acceleration sensor capable of reducing a leakage current and manufacturing method thereof is disclosed. A beam structure is disposed on a silicon substrate. The beam structure has a movable section, and the movable section is disposed spaced at a prescribed distance above silicon substrate. A movable electrode section is formed in one portion of movable section. Fixed electrodes made of an impurity diffusion layer are formed in silicon substrate to correspond to both sides of a movable electrode section. A peripheral circuit is formed in silicon substrate. The beam structure and the peripheral circuit are electrically connected by an electroconductive thin film, made of polysilicon. Then, when a voltage is applied to the 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.

Semiconductor acceleration sensor with beam structure

A method for fabricating a semiconductor sensor wherein deflection of a movable member is disclosed. A silicon oxide film is formed on a silicon substrate, and a movable member composed of polycrystalline silicon is formed on the silicon oxide film by means of a low-pressured chemical vapor deposition process. At this time, silane is caused to flow into an oven, and the supply of silane is stopped when a layer of polycrystalline silicon has been deposited on the silicon substrate, and a first polycrystalline silicon layer is formed. By means of stopping the supply of silane, a silicon oxide layer of a thickness of several angstroms to several tens of angstroms is formed on the first polycrystalline silicon layer by atmosphere O.sub.2. A second polycrystalline silicon layer of a thickness of 1 .mu.m is formed on the silicon oxide layer by means of causing silane to flow into the oven. Patterning by dry etching or the like through a photo-lithographic process is performed to form a movable member. The silicon oxide film below the movable member is then etched.

Semiconductor sensor method

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Nagoya, Japan

Masakazu Kanosue