IMMERSION PLATING TREATMENT FOR METAL-METAL INTERCONNECTS

• US 20070218672A1
• Filed: 12/20/2006
• Published: 09/20/2007
• Est. Priority Date: 03/15/2006
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Jacobs, Simon J.
• Application Number:
  US11/613,482
• Publication Number:
  US 20070218672A1
• Time in Patent Office: Days
• US Class Current: 438/597
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: H01L 21/7682 the dielectric comprising air gaps
• CPC Class Codes: H01L 21/7685 the layer covering a conductive structure H01L21/76849 takes precedence

Abstract

The present disclosure provides a method for manufacturing an interconnect in a semiconductor device, a method for manufacturing a digital micromirror device, a digital micromirror device and a method for manufacturing a projection display system. The method for manufacturing the digital micromirror device, without limitation, may include forming a first metal layer over a substrate and subjecting the first metal layer to an immersion deposition process, the immersion deposition process forming a passivating layer over the first metal layer. This method may also include forming a spacer layer over the first metal layer, the spacer layer having one or more openings therein, and forming a second metal layer over the spacer layer and in the one or more openings, the second metal layer contacting the passivating layer.

Claims

1. A method for manufacturing an interconnect in a semiconductor device, comprising:

forming a first metal layer over a substrate;

subjecting the first metal layer to an immersion deposition process, the immersion deposition process forming a passivating layer over the first metal layer; and

contacting the passivating layer with a second metal layer.

2. The method as recited in claim 1 wherein forming a first metal layer includes forming a first oxidizable metal layer.

3. The method as recited in claim 2 wherein forming a first oxidizable metal layer further includes forming a first metal oxide layer over the first oxidizable metal layer.

4. The method as recited in claim 3 wherein subjecting the first metal layer to an immersion deposition process includes subjecting the first oxidizable metal layer and the first metal oxide layer to an immersion deposition process.

5. The method as recited in claim 4 wherein the immersion deposition process removes at least a portion of the first metal oxide layer before depositing the passivating layer over the first oxidizable metal layer.

6. The method as recited in claim 5 wherein the immersion deposition process removes all of the first metal oxide layer before depositing the passivating layer over the first oxidizable metal layer.

7. The method as recited in claim 1 wherein metal ions used to form the passivating layer are reducible by the first metal layer.

8. The method as recited in claim 7 wherein the first metal layer comprises aluminum and the metal ions include zinc or tin metal ions.

9. The method as recited in claim 1 wherein the passivating layer includes an oxidized passivating layer, the oxidized passivating layer being a semiconductor or a conductor.

10. The method as recited in claim 1 wherein contacting the passivating layer with a second metal layer includes contacting the passivating layer with a second metal layer through an opening in an insulative material.

11. A method for manufacturing a digital micromirror device, comprising:

forming a first metal layer over a substrate;

subjecting the first metal layer to an immersion deposition process, the immersion deposition process forming a passivating layer over the first metal layer;

forming a spacer layer over the first metal layer, the spacer layer having one or more openings therein; and

forming a second metal layer over the spacer layer and in the one or more openings, the second metal layer contacting the passivating layer.

12. The method as recited in claim 11 wherein subjecting the first metal layer to an immersion deposition process includes subjecting the first metal layer to an immersion deposition process through the one or more openings in the spacer layer.

13. The method as recited in claim 11 wherein the subjecting occurs before forming the spacer layer.

14. The method as recited in claim 11 wherein the first metal layer forms at least a portion of electrode pads or a bias bus and the second metal layer forms at least a portion of a hinge for the digital micromirror device.

15. The method as recited in claim 11 wherein the first metal layer forms at least a portion of a hinge for the digital micromirror device and the second metal layer forms at least a portion of a mirror for the digital micromirror device.

16. The method as recited in claim 11 wherein forming a first metal layer includes forming a first oxidizable metal layer having a first metal oxide layer formed thereover.

17. The method as recited in claim 16 wherein the immersion deposition process removes at least a portion of the first metal oxide layer before depositing the passivating layer over the first oxidizable metal layer.

18. The method as recited in claim 11 wherein metal ions used to form the passivating layer are reducible by the first metal layer.

19. The method as recited in claim 18 wherein the first metal layer comprises aluminum and the metal ions include zinc or tin metal ions.

20. A digital micromirror device, comprising:

a first metal layer located over control circuitry located on or in a substrate;

a passivating layer located on the first metal layer; and

a second metal layer located over the first metal layer and contacting the passivating layer.

21. The digital micromirror device as recited in claim 20 wherein the first metal layer forms at least a portion of electrode pads or a bias bus and the second metal layer forms at least a portion of a hinge for the digital micromirror device, and further including a reflective surface formed over the second metal layer.

22. The digital micromirror device as recited in claim 20 wherein the first metal layer forms at least a portion of a hinge for the digital micromirror device and the second metal layer forms at least a portion of a reflective surface for the digital micromirror device.

23. The digital micromirror device as recited in claim 20 wherein the passivating layer is only located on the first metal layer where the second metal layer electrically contacts the first metal layer.

24. The digital micromirror device as recited in claim 20 wherein the first metal layer is a first oxidizable metal layer.

25. The digital micromirror device as recited in claim 24 wherein the first metal layer comprises aluminum.

26. The digital micromirror device as recited in claim 20 wherein the passivating layer is an oxidized passivating layer, the oxidized passivating layer being a semiconductor or a conductor.

27. The digital micromirror devices as recited in claim 20 wherein the passivating layer comprises any material that is further down an electromotive series than the first metal layer.

28. A method for manufacturing a projection display system, comprising:

providing a light source configured to produce a beam of light along a first light path;

positioning optics in the first light path, the optics configured to provide one or more color light beams;

forming one or more digital micromirror devices configured to receive the color light beams from the optics, modulate the light on a pixel-by-pixel basis and reflect light from ON pixels along a second light path, including;

forming a first metal layer over a substrate;

subjecting the first metal layer to an immersion deposition process, the immersion deposition process forming a passivating layer over the first metal layer;

forming a spacer layer over the first metal layer, the spacer layer having one or more openings therein; and

forming a second metal layer over the spacer layer and in the one or more openings, the second metal layer contacting the passivating layer;

providing control electronics for receiving image data and controlling the light source and the modulation of the digital micromirror devices; and

providing projection optics placed in the second light path magnifying and projecting an image on to a viewing screen.