Micro-mirror apparatus and production method therefor

• US 6,431,714 B1
• Filed: 10/05/2001
• Issued: 08/13/2002
• Est. Priority Date: 10/10/2000
• Status: Active Grant

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Sawada, Renshi, Maruno, Tohru, Higurashi, Eiji
• Primary Examiner(s): Sikder, Mohammad
• Application Number:
  US09/972,683
• Publication Number:
  US 20020041455A1
• Time in Patent Office: 312 Days
• Field of Search: 359/879, 359/880, 359/871, 359/872, 359/220, 359/221, 359/223, 359/224, 359/225, 359/226, 359/196, 359/197, 359/198, 359/298, 359/838, 359/839, 359/847, 359/848, 359/850
• US Class Current: 359/879
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: Y10S 359/904 Micromirror

Abstract

The micro-mirror apparatus of the invention has; a mirror 33, a plurality of torsion springs 35, 36 for supporting the mirror 33 so as to be tiltable relative to an upper substrate 27, a lower substrate 21 arranged facing a lower face of the mirror 33, a convex portion 34 provided on an upper face of the lower substrate 21 and a plurality of lower electrodes 22, 23 formed on an outer face of the convex portion 34. For the torsion spring 36, an aspect ratio of height/width in a cross-section perpendicular to a longitudinal direction thereof is at least 1.8.

Claims

1. A micro-mirror apparatus comprising:

a mirror;

a plurality of torsion springs which supports the mirror so as to be tiltable relative to an upper substrate;

a lower substrate arranged facing a lower face of the mirror;

a convex portion provided on an upper face of the lower substrate and facing a central portion of the mirror; and

a plurality of lower electrodes formed on an outer face of the convex portion.

2. A micro-mirror apparatus according to claim 1, wherein for the torsion spring, an aspect ratio of height/width in a cross-section perpendicular to a longitudinal direction thereof is at least 1.8.

3. A micro-mirror apparatus according to claim 1, wherein a concavity is formed in an upper face of the lower substrate at a position facing an outer peripheral edge of the mirror and surrounding the convex portion.

4. A micro-mirror apparatus according to claim 1, wherein a supporting point protuberance made from an insulating material is formed facing a center of the mirror.

5. A micro-mirror apparatus according to claim 1, wherein the torsion spring has a serpentine form, and a position restricting portion which restricts a displacement range of the torsion spring is provided on the upper substrate.

6. A micro-mirror apparatus according to claim 1, wherein the mirror, the torsion spring, and the upper substrate are integrally formed from silicon monocrystal, and this silicon monocrystal is connected to a spacer formed on the lower substrate.

7. A micro-mirror apparatus according to claim 1, wherein wiring patterns are formed on a lower face of the lower substrate, and each of the wiring patterns and the lower electrodes are conducted through a through hole formed in the lower substrate.

8. A micro-mirror apparatus according to claim 1, wherein the upper substrate is either one of an SOI substrate and a SIMOX substrate.

9. A micro-mirror apparatus according to claim 1, wherein an insulating film is formed on at least an opening edge portion of the concavity.