Spatial light modulator and method

• US 4,710,732 A
• Filed: 07/31/1984
• Issued: 12/01/1987
• Est. Priority Date: 07/31/1984
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Hornbeck, Larry J.
• Primary Examiner(s): Moskowitz, Nelson
• Application Number:
  US06/635,966
• Time in Patent Office: 1,218 Days
• Field of Search: 350/360, 350/356, 350/355, 350/385, 350/269, 350/109, 357/30, 357/51, 358/231, 358/233, 29/571, 156/643, 156/644, 156/646, 204/192 E, 332/7.51, 313/486, 313/465
• US Class Current: 359/291
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

Spatial light modulators with deflectable metal flaps hinged to conducting posts on a substrate are disclosed. The metal flaps and conducting post may be a single piece, and connected to addressing circuitry in the substrate. Also, plasma etching to fabricate the flaps without breakage is disclosed.

Claims

1. A method of fabricating a spatial light modulator with deflectable beams, comprising the steps of:

(a) apply a spacer on a substrate including electronic addressing circuitry;

(b) pattern said spacer to define post holes extending down to said subtrate;

(c) deposit a layer of metal on said spacer and post holes;

(d) define defectable beams in said metal so that each beam is hinged to the metal in one of said post holes;

(e) remove said spacer.

2. The method of claim 1 wherein said removal is by a plasma etch.

3. A method of fabricating a spatial light modulator with deflectable beams, comprising the steps of:

(a) spin a spacer onto a substrate including electronic addressing circuitry;

(b) pattern said spacer to define post holes extending down to said substrate;

(c) deposit metal on said spacer and post holes;

(d) remove said metal from said spacer except in the vicinity of said post holes;

(e) apply a second layer of metal on said spacer and metallized post holes;

(f) define deflectable beams in said second metal layer;

(g) remove said spacer.

4. A spatial light modulator, comprising:

(a) a plurality of pixels on a substrate with electronic addressing circuitry;

(b) each of said pixels including (i) an electrostatically deflectable reflecting element, (ii) a support holding said element spaced away from said substrate, and (iii) said element and support both electrical conductors and electrically connected, and said support connected electrically connected to said addressing circuitry.

5. A spatial light modulator, comprising:

(a) a plurality of pixels on a substrate with electronic addressing circuitry;

(b) each of said pixels including a single piece of metal with a support portion attached to said substrate, a hinge portion connected to said support portion, and a deflectable portion connected to said hinge portion and held spaced away from said substrate;

(c) said support portion electrically connected to said addressing circuitry and said deflectable portion over an electrode connected to said addressing circuitry.

6. The spatial light modulator of claim 5, wherein:

(a) said single piece of metal is in the shape of four square flaps, with each flap connected at a corner to a central post.

7. The spatial light modulator of claim 5, wherein:

(a) said electrode only extends beneath the portion of said deflectable portion near said support.

8. A spatial light modulator, comprising:

(a) a plurality of pixels on a substrate with electronic addressing circuitry;

(b) each of said pixels including a post and hinged electrically conductive flaps;

(c) said post including a first electrically conducting portion attached to said substrate and circuitry and an overlying metal portion contiguous with said hinged flaps.