Method of manufacturing three-dimensional structure and method of manufacturing oscillator

• US 20030022516A1
• Filed: 07/15/2002
• Published: 01/30/2003
• Est. Priority Date: 07/24/2001
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Arima, Michitsugu
• Granted Patent: US 6,730,534 B2
• Time in Patent Office: Days
• US Class Current: 438/737
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B81B 2201/0271 Resonators; ultrasonic resonators
• CPC Class Codes: B81C 1/00547 Etching processes not provided for in groups B81C1/00531 - B81C1/00539
• CPC Class Codes: G01P 2015/084 the mass being suspended at more than one of its sides, e.g. membrane-type suspension, so as to permit multi-axis movement of the mass
• CPC Class Codes: G01P 2015/0842 the mass being of clover leaf shape
• CPC Class Codes: H01L 21/00 Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
• CPC Class Codes: H03H 3/0072 of microelectro-mechanical resonators or networks micromembranes or microbeams B81B2203/01; manufacture of microstructural devices in general B81C

Abstract

The present invention provides a method of manufacturing a three-dimensional structure having portions different in thickness, the method comprising forming a laminated structure, which comprises at least two layers to be processed and at least one inner mask interposed between the layers, the layers and the inner mask being joined together, such that the laminated structure has top and bottom major surfaces, forming an outer mask on at least one of the major surfaces of the laminated structure, selectively etching the layers from one of the major surfaces of the laminated structure through the outer mask to expose the inner mask and then through the inner mask, so that the portions different in thickness are formed by one etching process.

Claims

1. A method of manufacturing a three-dimensional structure having at portions different in thickness, the method comprising:

forming a laminated structure, which comprises at least two layers to be processed and at least one inner mask interposed between the layers, the layers and the inner mask being joined together, such that the laminated structure has top and bottom major surfaces;

forming an outer mask on at least one of the major surfaces of the laminated structure;

selectively etching the layers from one of the major surfaces of the laminated structure through the outer mask to expose the inner mask and then through the inner mask, so that the portions different in thickness are formed by one etching process.

2. A method of manufacturing a three-dimensional structure according to claim 1, wherein the layers are of silicon, and the inner mask comprises a silicon oxide film.

3. A method of manufacturing a three-dimensional structure according to claim 1, wherein the laminated structure comprises a further inner mask provided on one of the layers, and a further layer to be processed provided on the further inner mask.

4. A method of manufacturing a three-dimensional structure according to claim 1, wherein formation of the laminated structure comprises providing an SOI substrate, which has a support layer, a buried oxide film layer, and an active layer, the layers being joined together, such that the SOI substrate has top and bottom major surfaces, and the active layer has an outer surface as one of the major surfaces of the SOI substrate, forming a mask on the outer surface of the active layer, joining a silicon substrate to the SOI substrate through the mask formed, and removing the support layer from the SOI substrate, whereby the resulting structure includes the active layer and the silicon substrate as the two layers to be processed, and the mask as the inner mask.

5. A method of manufacturing a three-dimensional structure according to claim 1, wherein formation of the laminated structure comprises providing a silicon substrate, which has top and bottom major surfaces, forming a mask on one of the major surfaces of the silicon substrate, and joining the silicon substrate to another silicon substrate through the mask formed, whereby the resulting structure includes the silicon substrates as the two layers to be processed, and the mask as the inner mask.

6. A method of manufacturing an oscillator comprising a support, a movable plate having a reflecting surface, and elastic members connecting the movable plate and the support, the oscillator cooperating with a driver, which oscillates the movable plate with respect to the support, to constitute an optical scanner, which scans a beam of light reflected by the reflecting surface of the movable plate, the method comprising:

forming a laminated structure, which comprises two layers to be processed and an inner mask interposed between the layers, the layers and the inner mask being joined together, such that the laminated structure has top and bottom major surfaces;

forming an outer mask on at least one of the major surfaces of the laminated structure;

selectively etching the layers from one of the major surfaces of the laminated structure through the outer mask to expose the inner mask and then through the inner mask, so that the portions different in thickness are formed by one etching process, the portions including a relatively thick portion serving as a support, and relatively thin portion as a movable plate.

7. A method of manufacturing an oscillator comprising supports, movable electrodes, and levers connecting the movable electrodes and the supports, so that the movable electrodes is allowed to oscillate with respect to the supports, the oscillator cooperating with fixed electrodes facing to the movable electrodes to constitute an acceleration sensor for sensing acceleration, the method comprising:

forming a laminated structure, which comprises three layers to be processed and two inner masks interposed between the layers, the layers and the inner masks being joined together, such that the laminated structure has top and bottom major surfaces;

forming an outer mask on at least one of the major surfaces of the laminated structure;

selectively etching the layers from one of the major surfaces of the laminated structure through the outer mask to expose the inner mask and then through the inner mask, so that portions different in thickness are formed by one etching process, the portions including relatively thick portions serving as supports, intermediate-thickness portions as movable electrodes, and relatively thin portions as levers.