MEMS with flexible portions made of novel materials

• US 7,071,520 B2
• Filed: 06/21/2002
• Issued: 07/04/2006
• Est. Priority Date: 08/23/2000
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Reflectivity, Inc. (Texas Instruments, Inc.)
• Inventors: Reid, Jason S.
• Primary Examiner(s): Pham, Hoai
• Assistant Examiner(s): DUONG, KHANH B
• Application Number:
  US10/176,478
• Publication Number:
  US 20020185699A1
• Time in Patent Office: 1,474 Days
• Field of Search: 257/459, 257/414, 257/776, 257/731, 257/736, 257/773, 257/252, 257/415, 257/659, 438/52, 438/459, 438/53, 438/455, 438/619, 438/951
• US Class Current: 257/414
• 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

MEMS devices are provided that are capable of movement due to a flexible portion formed of unique materials for this purpose. The MEMS device can have a flexible portion formed of a nitride or oxynitride of at least one transition metal, and formed of a nitride or oxynitride of at least one metalloid or near metalloid; a flexible portion formed of a single transition metal nitride or oxynitride and in the absence of any other metal or metalloid nitrides; a flexible portion formed of one or more late transition metal nitrides or oxynitrides; a flexible portion formed of a single transition metal in nitride form, and an additional metal substantially in elemental form; or a flexible portion formed of at least one metalloid nitride or oxynitride. The MEMS devices can be any device, though preferably one with a flexible portion such as an accelerometer, DC relay or RF switch, optical cross connect or optical switch, or micromirror arrays for direct view and projection displays. The flexible portion (e.g. the hinge of the micromirror) is preferably formed by sputtering a metal and/or metalloid target in nitrogen ambient so as to result in a sputtered hinge. It is also possible to form other parts of the MEMS device (e.g structural parts that do not flex).

Claims

1. A MEMS device, comprising:

a flexible portion formed of a) a first layer that comprises silicon nitride; and

b) a second layer that comprises a nitride or oxynitride of at least one transition metal and a nitride or oxynitride of at least one metalloid or near metalloid.

2. The MEMS device of claim 1, wherein the transition metal is an early transition metal and the metalloid is boron.

3. The MEMS device of claim 1, wherein the transition metal is a late transition metal and the metalloid is boron or silicon.

4. The MEMS device of claim 1, wherein the flexible portion is a mirror or RF switch hinge.

5. The MEMS device of claim 4, wherein the mirror is a mirror in an optical switch or projection display.

6. The MEMS device of claim 1, wherein a flexible portion and a non-flexible portion are formed of the nitride of at least one transition metal, and a nitride of at least one metalloid.

7. The MEMS device of claim 1, wherein the flexible portion is formed of nitrides of more than one transition metal and at least one metalloid.

8. The MEMS device of claim 7, wherein the transition metals are selected from Mo, Ta, Ti, Cr and W, and the metalloid is selected from B, Si, Ge or As.

9. The MEMS device of claim 1, wherein the near metalloid is Al, C or P.

10. The MEMS device of claim 9, wherein the transition metal is Mo, Ta, Ti, Cr or W.

11. A MEMS device;

comprising;

a flexible portion formed of a) a first layer that comprises silicon nitride; and

b) a second layer that comprises one or more late transition metal nitrides or oxynitrides.

12. The MEMS device of claim 11, further comprising an early transition metal or metalloid in elemental or compound form.

13. The MEMS device of claim 12, wherein the early transition metal or metalloid is in compound form.

14. The MEMS device of claim 13, wherein the compound form is a nitride or oxynitride.

15. The MEMS device of claim 12, wherein the early transition metal or metalloid is selected from Ti, V, Cr, Zr, Nb, Mo, Ta, W, B, Si, Ge, Sb, or As.

16. The MEMS device of claim 12, wherein the late transition metal is from column 8B of the periodic table and wherein the metalloid is silicon.

17. The MEMS device of claim 11, wherein the late transition metal is Co, Ni, Cu, Zn, Pd, Ag or Pt.

18. The MEMS device of claim 11, further comprising a metal in elemental form.

19. A MEMS device;

comprising;

a flexible portion formed of a) a first layer that comprises silicon nitride; and

b) a second layer that comprises a single transition metal in nitride form, and an additional metal substantially in elemental form.

20. The MEMS device of claim 19, wherein the metal in elemental form is provided by implantation.

21. The MEMS device of claim 19, wherein the transition metal is an early transition metal, and the additional metal is a transition metal or metalloid.

22. The MEMS device of claim 21, wherein the early transition metal is selected from Y, Zr, V, Nb, Mo, Cr, Ta or W.

23. A MEMS device, comprising:

a flexible portion formed of a) a first layer that comprises silicon nitride; and

b) a second layer that comprises at least one metalloid nitride or oxynitride and a transition metal, wherein the transition metal is in compound form and is a nitride or oxynitride.

24. The MEMS device of claim 23, further comprising an additional metalloid in elemental form.

25. The MEMS device of claim 23, wherein the metalloid is B, Si, Ge, As, or Sb.

26. The MEMS device of claim 23, wherein the transition metal is a late transition metal.

27. The MEMS device of claim 26, wherein the late transition metal is Co, Ni or Cu.

28. The MEMS device of claim 23, wherein the transition metal is an early transition metal.

29. The MEMS device of claim 28, wherein the early transition metal is Ti, Cr, Mo, Ta or W.

30. The MEMS device of claim 23, wherein the flexible portion is a hinge of a MEMS mirror, DC relay or RF switch.