Electrostatic drive type mems element, manufacturing method thereof, optical mems element, optical modulation element, glv device, and laser display

• US 20040076008A1
• Filed: 08/25/2003
• Published: 04/22/2004
• Est. Priority Date: 12/26/2001
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ikeda, Koichi
• Granted Patent: US 7,116,462 B2
• Time in Patent Office: Days
• US Class Current: 362/259
• CPC Class Codes: B81B 2201/045 Optical switches
• CPC Class Codes: B81B 2203/04 Electrodes
• CPC Class Codes: B81C 1/0015 Cantilevers switches using MEMS H01H1/0036; electrostatic relays using micromechanics H01H59/0009; microelectro-mechanical resonators H03H9/02244
• CPC Class Codes: B81C 2201/0109 Sacrificial layers not provided for in B81C2201/0107 - B81C2201/0108
• CPC Class Codes: B81C 2201/0173 Thermo-migration of impurities from a solid, e.g. from a doped deposited layer
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

The present invention provides an electrostatic drive type MEMS device and a manufacturing method thereof, in which flattening the surface of a driving side electrode, improving performance, and further the improvements of the degree of freedom of designing in the manufacturing process are implemented. In addition, the present invention provides a GLV device using this MEMS device, and further a laser display using this GLV device.

In the present invention an electrostatic drive type MEMS device includes a substrate side electrode and a beam having a driving side electrode driven by electrostatic attraction force or electrostatic repulsion force that acts between the substrate side electrode and driving side electrode, in which the substrate side electrode is formed of an impurities-doped conductive semiconductor region in a semiconductor substrate.

Claims

1. An electrostatic drive type MEMS device, characterized by comprising a substrate side electrode and a beam that is disposed to oppose said substrate side electrode and that has a driving side electrode driven by electrostatic attraction force or electrostatic repulsion force that acts between the substrate side electrode and said driving side electrode, said substrate side electrode being formed of an impurities-doped conductive semiconductor region in a semiconductor substrate.

2. An electrostatic drive type MEMS device according to claim 1, wherein said conductive semiconductor region is electrically insulated from the peripheral region of said semiconductor substrate through being isolated by insulation by means of selective oxidation, or trench isolation.

3. A manufacturing method of an electrostatic drive type MEMS device, characterized by comprising the processes of:

forming a substrate side electrode that is insulated to be isolated from other parts by doping impurities onto the surface of a semiconductor substrate, selectively forming a sacrificial layer including the upper part of said substrate side electrode,

forming a beam having a driving side electrode on said sacrificial layer, and

removing said sacrificial layer.

4. A manufacturing method of an electrostatic drive type MEMS device according to claim 3, wherein

said doping of impurities is carried out by means of an ion infusion method, a thermal diffusion method or a solid phase diffusion method.

5. An optical MEMS device, characterized by comprising a substrate side electrode and a beam that is disposed to oppose said substrate side electrode and that has a light reflective film cum driving side electrode driven by electrostatic attraction force or electrostatic repulsion force that acts between the substrate side electrode and said driving side electrode, said substrate side electrode being formed of an impurities-doped conductive semiconductor region in a semiconductor substrate.

6. A light modulation device, characterized by comprising a substrate side electrode and a beam that is disposed to oppose said substrate side electrode and that has a light reflective film cum driving side electrode driven by electrostatic attraction force or electrostatic repulsion force that acts between the substrate side electrode and said driving side electrode, said substrate side electrode being formed of an impurities-doped conductive semiconductor region in a semiconductor substrate.

7. A GLV device, characterized by comprising a common substrate side electrode and a plurality of beams that are independently disposed in parallel to each other to oppose said common substrate side electrode and that each have a light reflective film cum driving side electrode driven by electrostatic attraction force or electrostatic repulsion force that acts between the substrate side electrode and said driving side electrode, said substrate side electrode being formed of an impurities-doped conductive semiconductor region in a semiconductor substrate.

8. A laser display comprising a laser beam source and a GLV device that is disposed on an optical axis of the laser beam emitted from said laser beam source to modulate the strength of the laser beam, characterized in that said GLV device includes a common substrate side electrode and a plurality of beams that are independently disposed in parallel to each other to oppose said common substrate side electrode and that each have a light reflective film cum driving side electrode driven by electrostatic attraction force or electrostatic repulsion force that acts between the substrate side electrode and said driving side electrode, said substrate side electrode being formed of an impurities-doped conductive semiconductor region in a semiconductor substrate.