Grated landing area to eliminate sticking of micro-mechanical devices

• US 5,665,997 A
• Filed: 03/31/1994
• Issued: 09/09/1997
• Est. Priority Date: 03/31/1994
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Randall, John N., Weaver, Douglas J.
• Primary Examiner(s): Prenty, Mark V.
• Application Number:
  US08/221,735
• Time in Patent Office: 1,258 Days
• Field of Search: 257/414, 257/618, 257/629, 257/649, 257/773
• US Class Current: 257/414
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/1465 of the hybrid type
• CPC Class Codes: H01L 27/14685 Process for coatings or optical elements

Abstract

A digital micro-mirror device (10), whose contacting elements (11, 17) are not prone to stick together. In the case of a deflecting mirror device, landing electrodes (17) are covered with a grating (19), which reduces the contacting area but still permits conduction between the mirror (11) and the landing electrode (17). Alternatively, the landing electrode (17) can be fabricated as a grated surface.

Claims

1. A micro-mechanical device, comprising:

one or more deflecting beam elements, each beam element having a deflectable beam, an address electrode, and a landing electrode;

wherein the spacing of each said beam from an associated landing electrode permits said beam to contact said landing electrode in response to a voltage applied to said address electrode; and

wherein each said landing electrode is covered with a grating at least where said beam contacts said landing electrode.

2. The micro-mechanical device of claim 1, wherein said beam and said landing electrode are made from an electrically conductive material and wherein said grating has sufficiently thin lines or spaces so as to not substantially inhibit electrical conduction between said beam and said landing electrode.

3. The micro-mechanical device of claim 1, wherein said grating is fabricated from silicon nitride.

4. The micro-mechanical device of claim 1, wherein said grating covers at least part of said address electrode as well as at least part of said landing electrode.

5. The micro-mechanical device of claim 1, wherein each said beam element has two address electrodes and two landing electrodes and wherein said grating covers the contact area of said two landing electrodes.

6. The micro-mechanical device of claim 1, wherein said grating has lines having a width of approximately 0.2 to 0.3 micrometers.

7. A micro-mechanical device, comprising:

one or more deflecting beam elements, each beam element having a deflectable beam, an address electrode, and a landing electrode;

wherein the spacing of each said beam from an associated landing electrode permits said beam to contact said landing electrode in response to a voltage applied to said address electrode; and

wherein each said landing electrode has a grated surface at least where said beam contacts said landing electrode.

8. The micro-mechanical device of claim 7, wherein said beam and said landing electrode are made from an electrically conductive material.

9. The micro-mechanical device of claim 7, wherein each said beam element has two address electrodes and two landing electrodes and wherein said grated surface is at the contact area of said two landing electrodes.

10. The micromechanical device of claim 7, wherein said grated surface has lines having a width of approximately 0.2 to 0.3 micrometers.