METHOD OF FABRICATING MICRO-MIRROR ASSEMBLY

• US 20100149623A1
• Filed: 12/17/2008
• Published: 06/17/2010
• Est. Priority Date: 12/17/2008
• Status: Abandoned Application

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, Lawlor, Vincent Patrick, McAvoy, Gregory John, O'Reilly, Ronan Padraig Sean
• Application Number:
  US12/336,530
• Publication Number:
  US 20100149623A1
• Time in Patent Office: Days
• US Class Current: 359/291
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81C 1/00174 See-saws
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A method of fabricating a micro-mirror assembly. The method comprises the steps of: (a) forming a pair of electrodes spaced apart on a surface of a substrate; (b) depositing a layer of sacrificial material over the electrodes and the substrate; (c) defining a stem opening in the sacrificial material so as to form a scaffold; (d) depositing a layer of resiliently flexible material over the scaffold; (e) depositing a metal layer over the flexible layer; (f) etching through the metal layer and the flexible layer to define an individual micro-mirror; and (g) removing the sacrificial material to provide the micro-mirror assembly. The method produces a micro-mirror assembly with minimal number of MEMS fabrication steps.

Claims

1. A method of fabricating a micro-mirror assembly, said method comprising the steps of:

(a) forming a pair of electrodes spaced apart on a surface of a substrate, said electrodes being connected to underlying electronic circuitry in said substrate;

(b) depositing a layer of sacrificial material over said electrodes and said substrate;

(c) defining a stem opening in said sacrificial material so as to form a scaffold, said stem opening being positioned between said electrodes;

(d) depositing a layer of resiliently flexible material over said scaffold;

(e) depositing a metal layer over said flexible layer;

(f) etching through said metal layer and said flexible layer to define an individual micro-mirror supported on a stem of flexible material, said micro-mirror comprising a metal layer fused to a support platform; and

(g) removing said sacrificial material to provide said micro-mirror assembly.

2. The method of claim 1, wherein said resiliently flexible material is comprised of polydimethylsiloxane (PDMS).

3. The method of claim 1, wherein said sacrificial material is photoresist.

4. The method of claim 1, wherein said metal layer is comprised of aluminium.

5. The method of claim 1, wherein an array of micro-mirrors are fabricated simultaneously on said substrate, said array defining a digital micro-mirror device.

6. The method of claim 1, wherein said substrate is a silicon substrate including one or more CMOS layers, said CMOS layers comprising said electronic circuitry.

7. A micro-mirror assembly comprising a tiltable mirror supported by a stem, wherein said stem is comprised of a resiliently flexible material.

8. The micro-mirror assembly of claim 7, wherein said tiltable mirror comprises a metal layer having an upper reflective surface.

9. The micro-mirror assembly of claim 8, wherein said tiltable mirror further comprises a support platform onto which said metal layer is mounted, said support platform being comprised of said resiliently flexible material.

10. The micro-mirror assembly of claim 7, wherein said resiliently flexible material is comprised of polydimethylsiloxane (PDMS).

11. The micro-mirror assembly of claim 7, wherein said mirror is tiltable by an electrostatic force.

12. The micro-mirror assembly of claim 7 further comprising a pair of electrodes positioned on either side of said stem, said electrodes providing, at least part of said electrostatic force.