MEMS device made of transition metal-dielectric oxide materials

• US 7,057,251 B2
• Filed: 07/17/2002
• Issued: 06/06/2006
• Est. Priority Date: 07/20/2001
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Reflectivity, Inc. (Texas Instruments, Inc.)
• Inventors: Reid, Jason S.
• Primary Examiner(s): Smith, Zandra V.
• Assistant Examiner(s): DUONG, KHANH B
• Application Number:
  US10/198,389
• Publication Number:
  US 20030036215A1
• Time in Patent Office: 1,420 Days
• Field of Search: 257/295, 257/296, 257/306, 257/310, 257/415, 438/52, 438/53, 438/455, 438/459, 438/619, 438/951
• US Class Current: 257/432
• CPC Class Codes: B81B 2201/045 Optical switches
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81B 3/0078 Constitution or structural means for improving mechanical properties not provided for in B81B3/007 - B81B3/0075

Abstract

Micromechanical devices are provided that are capable of movement due to a flexible portion. The micromechanical device can have a flexible portion formed of an oxide of preferably an element from groups 3A to 6A of the periodic table (preferably from the first two rows of these groups) and a late transition metal (preferably from groups 8B or 1B of the periodic table). The micromechanical devices can be any device, particularly MEMS sensors or actuators preferably having a flexible portion such as an accelerometer, DC relay or RF switch, optical cross connect or optical switch, or a micromirror part of an array for direct view and projection displays. The flexible portion is preferably formed by sputtering a target having a group 8B or 1B element and a selected group 3A to 6A element, namely B, Al, In, Si, Ge, Sn, or Pb. The target can have other major constituents or impurities (e.g. additional group 3A to 6A element(s)). The target is reactively sputtered in a oxygen ambient so as to result in a sputtered hinge. It is possible to form both stiff and/or flexible portions of the micromechanical device in this way.

Claims

1. A micromechanical device, comprising:

a substrate;

a movable element formed in or on the substrate with the movable element having a reflective layer thereon or therein;

a hinge allowing movement of the movable element relative to the substrate, further comprising;

a flexible hinge portion tha comprises an alloy of an oxide compound and a late transition metal, wherein the oxide compound is in the form of a matrix surrounding discrete late transition metal islands; and

wherein the reflective layer comprises Al, Ti, or Au.

2. The micromechanical device of claim 1, wherein the oxide compound is an oxide of silicon, boron or aluminum.

3. The micromechanical device of claim 2, wherein the oxide compound is a silicon oxide or aluminum oxide.

4. The micromechanical device of claim 1, wherein the late transition metal is selected from the groups 8B or 1B of the periodic table.

5. The micromechanical device of claim 1, wherein the late transition metal is a ferromagnetic metal.

6. The micromechanical device of claim 1, which is a MEMS sensor or actuator.

7. The micromechanical device of claim 1, wherein the late transition metal is a noble metal.

8. The micromechanical device of claim 1, wherein the late transition metal is Co, Ni, Pd, Pt, Ag or Au.

9. The micromechanical device of claim 1, wherein the oxide comprises less than 0.1 at % nitrogen.

10. The micromechanical device of claim 1, wherein the oxide is an oxynitride that comprises up to 10 at % nitrogen.

11. The micromechanical device of claim 1, wherein at least a flexible hinge portion comprises the oxide compound and the late transition metal.

12. The micromechanical device of claim 1, wherein the substrate is a semiconductor or light transmissive substrate.

13. The micromechanical device of claim 1, wherein the movable element and/or the hinge are formed of the oxide compound and the late transition metal.

14. The micromechanical device of claim 13, further comprising posts or walls for connecting the movable element to the substrate via the hinge.

15. The micromechanical device of claim 1, wherein the hinge is a sputtered hinge.

16. The micromechanical device of claim 1, which is a sensor.

17. The micromechanical device of claim 1, wherein the micromirror device is a light beam steering device.

18. The micromechanical device of claim 17, wherein the light beam steering device is within an optical switch.

19. The micromechanical device of claim 1, wherein the micromirror device is part of a micromirror array in a display.

20. The micromechanical device of claim 19, wherein the display is a direct view or projection display.

21. A micromechanical device comprising:

a micromirror that further comprises a reflecting surface of a movable portion;

a flexible hinge portion that comprises a layer formed of one or more oxide compounds in a matrix surrounding a late transition metal; and

wherein the layer comprises an oxide or element selected from the late transition metals and an oxide of a group 3A or 4A element; and

wherein the flexible hinge portion further comprises a material that comprises an oxide of Al, Si or B and a late transition metal that does not form an oxide.

22. The micromechanical device of claim 21, wherein the layer is a substantially homogenous multiphase composite.

23. The micromechanical device of claim 21, wherein the layer is at least in an area of the device capable of flexing.

24. The micromechanical device of claim 21, wherein the layer is amorphous.

25. The micromechanical device of claim 21, wherein the layer has a long range order of less than 100 angstroms.

26. The micromechanical device of claim 21, wherein the oxide of the group 3A or 4A element is an oxide of selected elements from group 3A or 4A.

27. The micromechanical device of claim 26, wherein the oxide of group 3A or 4A element comprises an oxide of boron, aluminum or silicon.

28. The micromechanical device of claim 26, wherein the oxide of the group 3A or 4A element comprises an oxide of indium, tin, germanium and/or lead.

29. The micromechanical device of claim 21, wherein the oxide or element selected from the late transition metals is an oxide or element selected from Fe, Co or Ni.

30. The micromechanical device of claim 29, wherein the late transition metal is Co.

31. The micromechanical device of claim 30, wherein the oxide from group 3A or 4A is an oxide of silicon or aluminum.

32. The micromechanical device of claim 21, wherein the oxide or element selected from the late transition metals is an oxide or element selected from Ru, Rh, Pd, Pt, Ir, Os, Ag or Au.

33. The micromechanical device of claim 21, wherein the oxide or element selected from the late transition metals is a conductive oxide.

34. The micromechanical device of claim 21, wherein the late transition metal is Ru, Rh, Ir or Os.

35. The micromechanical device of claim 34, wherein the late transition metal is Ru or Ir.

36. The micromechanical device of claim 21, wherein the flexible hinge portion further comprises a material that comprises a late transition metal that forms an oxide.

37. The micromechanical device of claim 21, wherein the flexible hinge portion further comprises a material that comprises a late transition metal that does not form an oxide.

38. The micromechanical device of claim 21, wherein the flexible hinge portion further comprises a material that comprises an oxide of In, Sn, Ti and/or Pb, and an oxide of Ru, Rh, Os or Ir.

39. The micromechanical device of claim 38, wherein the flexible hinge portion further comprises a material that has a long range order of less than 100 angstrom.

40. The micromechanical device of claim 21, wherein the late transition metal is Pd, Pt, or Au.

41. The micromechanical device of claim 21, wherein the layer comprises a sputtered material.

42. A micromechanical device, comprising:

a flexible hinge portion that comprises an alloy of an oxide compound and a late transition metal, wherein the oxide compound is in the form of a matrix surrounding discrete late transition metal islands; and

wherein the late transition metal is a ferromagnetic metal.

43. A micromechanical device, comprising:

a flexible hinge portion that comprises an alloy of an oxide compound and a late transition metal, wherein the oxide compound is in the form of a matrix surrounding discrete late transition metal islands;

wherein the late transition metal is Co, Ni, Pd, Pt, Ag or Au.

44. A rnicrornechanical device comprising:

a micromirror that further comprises a reflecting surface of a movable portion;

a flexible hinge portion that comprises a layer formed of one or more oxide compounds in a matrix surrounding a late transition metal;

wherein the layer comprises an oxide or element selected from the late transition metals and an oxide of a group 3A or 4A element;

wherein the flexible hinge portion further comprises a material that comprises an oxide of In, Sn, Ti and/or Pb, and an oxide of Ru, Rh, Os or Ir;

wherein the oxide of the group 3A or 4A element comprises an oxide of indium, tin, germanium and/or lead; and

wherein the oxide of the group 3A or 4A element is an oxide of selected elements from group 3A or 4A.

45. A micromechanical device comprising:

a micromirror that further comprises a reflecting surface of a movable portion;

a flexible hinge portion that comprises a layer formed of one or more oxide compounds in a matrix surrounding a late transition metal;

wherein the layer comprises an oxide or element selected from the late transition metals and an oxide of a group 3A or 4A element;

wherein the flexible hinge portion further comprises a material that comprises an oxide of In, Sn, Ti and/or Pb, and an oxide of Ru, Rh, Os or Ir; and

wherein the oxide or element selected from the late transition metal is an oxide or element selected from Fe, Co or Ni.

46. A micromechanical device comprising:

a micromirror that further comprises a reflecting surface of a movable portion;

a flexible hinge portion that comprises a layer formed of one or more oxide compounds in a matrix surrounding a late transition metal;

wherein the layer comprises an oxide or element selected from the late transition metals and an oxide of a group 3A or 4A element; and

wherein the flexible hinge portion further comprises a material that comprises an oxide of In, Sn, Ti and/or Pb, and an oxide of Ru, Rh, Os or Ir; and

wherein the flexible hinge portion further comprises a material that comprises a late transition metal that does not form an oxide.