MEMS device and interconnects for same

• US 8,097,174 B2
• Filed: 04/21/2010
• Issued: 01/17/2012
• Est. Priority Date: 12/20/2006
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Chung, Wonsuk, Ganti, SuryaPrakash, Zee, Stephen
• Primary Examiner(s): Ahmed, Shamim
• Application Number:
  US12/764,454
• Publication Number:
  US 20100202038A1
• Time in Patent Office: 636 Days
• Field of Search: 216/2, 216/24, 216/41, 216/58, 216/83
• US Class Current: 216/2
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26

Abstract

A microelectromechanical systems device having an electrical interconnect connected to at least one of an electrode and a movable layer within the device. At least a portion of the electrical interconnect is formed from the same material as a movable layer of the device. A thin film, particularly formed of molybdenum, is provided underneath the electrical interconnect. The movable layer preferably comprises aluminum.

Claims

1. A method of forming a microelectromechanical systems device, comprising:

providing an electrode in an array region;

depositing a sacrificial layer over the electrode in the array region;

depositing a thin film over the sacrificial layer and in an interconnect region;

forming a movable layer over the thin film; and

forming an electrical interconnect layer over the thin film in the interconnect region, wherein the electrical interconnect layer comprises a same material as the movable layer.

2. The method of claim 1, further comprising forming a mechanical layer over the movable layer.

3. The method of claim 1, wherein forming the electrical interconnect layer includes simultaneously etching the electrical interconnect layer and the movable layer using a first etchant.

4. The method of claim 3, wherein the thin film is substantially resistant to etching by the first etchant.

5. The method of claim 4, wherein the thin film is under the electrical interconnect layer and the movable layer during simultaneous etching.

6. The method of claim 1, wherein the thin film comprises molybdenum.

7. The method of claim 1, wherein the sacrificial layer comprises molybdenum.

8. The method of claim 1, further comprising performing a release etch to remove the sacrificial layer to form an optical cavity.

9. The method of claim 8, wherein the release etch also removes the thin film.

10. The method of claim 8, further comprising protecting the electrical interconnect and the thin film in the array region from the release etch with an inorganic dielectric material.

11. The method of claim 1, wherein the electrical interconnect layer comprises aluminum.

12. The method of claim 1, wherein depositing the thin film is conducted before forming the movable layer.

13. The method of claim 1, wherein the device is an interferometric modulator.