# US 7,465,599 B2 · Method for manufacturing physical quantity sensor

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- Number: US 7,465,599 B2
- Document ID: US7465599B2
- Status: Granted
- Kind: B2
- Application number: 11/896,171
- Filed: 2007-08-30
- Published: 2008-01-10
- Granted: 2008-12-16
- Earliest claimed: 2004-07-06
- Assignees: Denso Corporation
- Inventors: Makoto Asai
- Web page: https://patentgrep.com/patent/US7465599B2

## CPC

- B81C 1/00626: {Processes for achieving a desired geometry not provided for in groups B81C1/00563 - B81C1/00619}
- G01P 15/0802: {Details}
- G01P 15/125: by capacitive pick-up
- B81B 2201/0235: Accelerometers
- B81B 2201/0292: Sensors not provided for in B81B2201/0207 - B81B2201/0285
- B81B 2203/0118: Cantilevers
- B81C 2201/014: by depositing an etch stop layer, e.g. silicon nitride, silicon oxide, metal
- B81C 2201/019: Bonding or gluing multiple substrate layers
- G01P 2015/0814: {for translational movement of the mass, e.g. shuttle type}
- B81C: PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS (making microcapsules or microballoons B01J13/02; processes or apparatus specially adapted for the manufacture or treatment of piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/01)
- G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G})
- B81B: MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES (piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/00, H10N35/00)

## Abstract

A physical quantity sensor includes: a semiconductor substrate; a cavity disposed in the substrate and extending in a horizontal direction of the substrate; a groove disposed on the substrate and reaching the cavity; a movable portion separated by the cavity and the groove so that the movable portion is movably supported on the substrate; and an insulation layer disposed on a bottom of the movable portion so that the insulation layer provides a roof of the cavity.

## Claims

### Claim 1

A method for manufacturing a physical quantity sensor, which includes a multi-layered substrate, a cavity, a groove portion and a movable portion, wherein the multi-layered substrate includes a support substrate, an embedded insulation film and a semiconductor layer, which are stacked in this order, wherein the cavity is disposed between the semiconductor layer and the embedded insulation film and extends in a horizontal direction of the substrate, wherein the groove portion is disposed in the semiconductor layer and reaches the cavity, wherein the movable portion is disposed in the semiconductor layer and separated from the embedded insulation film by the cavity and the groove portion, the method comprising the steps of:
preparing the multi-layered substrate in such a manner that an intermediate insulation layer is disposed in the semiconductor layer at a predetermined position to be a bottom of the movable portion;
forming the groove portion from a top surface of the semiconductor layer so that the groove portion extends in a vertical direction of the multi-layered substrate and reaches the embedded insulation film; and
etching a part of the semiconductor layer disposed between the embedded insulation film and the intermediate insulation layer from a bottom of the groove portion by a dry-etching method with using the embedded insulation film and the intermediate insulation layer as an etching stopper so that the cavity is formed to extend in the horizontal direction of the multi-layered substrate.

### Claim 2 (depends on 1)

The method according to claim 1, wherein
the groove portion includes a plurality of grooves having different widths.

### Claim 3 (depends on 1)

The method according to claim 1, wherein
the semiconductor layer includes a first semiconductor layer and a second semiconductor layer, and
the step of preparing the multi-layered substrate includes the steps of:
depositing an embedded insulation film on the support substrate;
depositing the first semiconductor layer on the embedded insulation film;
depositing the intermediate insulation layer having a predetermined pattern on the first semiconductor layer; and
depositing the second semiconductor layer on the intermediate insulation layer.

### Claim 4 (depends on 1)

The method according to claim 1, wherein
the semiconductor layer includes a first semiconductor layer and a second semiconductor layer, and
the step of preparing the multilayered substrate includes the steps of:
preparing a first substrate including the support substrate, the embedded insulation film, and the first semiconductor layer, which are stacked in this order;
preparing a second substrate including the second semiconductor layer and the intermediate insulation layer, which is embedded in a surface of the second semiconductor layer; and
bonding the first substrate and the second substrate in such a manner that a surface of the intermediate insulation layer is bonded to a surface of the first semiconductor layer of the first substrate.

### Claim 5 (depends on 1)

The method according to claim 1, wherein
the semiconductor layer includes a first semiconductor layer and a second semiconductor layer, and
the step of preparing the multilayered substrate includes the steps of:
preparing a first substrate including the support substrate, the embedded insulation film, and the first semiconductor layer, which are stacked in this order, wherein the intermediate insulation layer is embedded in a surface of the first semiconductor layer;
preparing a second substrate including the second semiconductor layer; and
bonding the first substrate and the second substrate in such a manner that a surface of the intermediate insulation layer is bonded to a surface of the second semiconductor layer of the second substrate.

### Claim 6

A method for manufacturing a physical quantity sensor, which includes a semiconductor substrate, a cavity, a groove and a movable portion, wherein the cavity is disposed in the substrate and extends in a horizontal direction of the substrate, wherein the groove is disposed on a surface of the substrate and reaches the cavity, wherein the movable portion is separated by the groove and the cavity so that the movable portion is movably supported by the substrate, the method comprising the steps of:
preparing the semiconductor substrate including an intermediate insulation layer embedded in the substrate at a predetermined position of a movable-portion-to-be-formed region;
etching a top surface of the semiconductor substrate so that the groove is formed, wherein the groove extends in a vertical direction of the substrate and penetrates the intermediate insulation layer;
isotropically etching the semiconductor substrate from a bottom of the groove by using the intermediate insulation layer as an etching stopper so that the cavity extending in the horizontal direction of the substrate is formed for providing the movable portion.

### Claim 7 (depends on 6)

The method according to claim 6, wherein
the intermediate insulation layer embedded in the semiconductor substrate is formed by a separation by implantation of oxygen method.