Strengthened Micro-Electromechanical System Devices and Methods of Making Thereof

• US 20120205752A1
• Filed: 02/14/2011
• Published: 08/16/2012
• Est. Priority Date: 02/14/2011
• Status: Active Grant

• Current Assignee: ROHM Co., Ltd.
• Original Assignee: Kionix Incorporated (ROHM Co., Ltd.)
• Inventors: Blackmer, Charles W., Adams, Scott G., Hocking, Andrew S., Lynch, Kristin J., Shah, Ashish A.
• Granted Patent: US 8,664,731 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81B 2203/033 Trenches
• CPC Class Codes: B81C 1/00698 Electrical characteristics, e.g. by doping materials
• CPC Class Codes: H01L 21/76232 of trenches having a shape other than rectangular or V-shape, e.g. rounded corners, oblique or rounded trench walls H01L21/76229 takes precedence

Abstract

In an embodiment, a micro-electromechanical device can include a substrate, a beam, and an isolation joint. The beam can be suspended relative to a surface of the substrate. The isolation joint can be between a first portion and a second portion of the beam, and can have a non-linear shape. In another embodiment, a micro-electromechanical device can include a substrate, a beam, and an isolation joint. The beam can be suspended relative to a surface of the substrate. The isolation joint can be between a first portion and a second portion of the beam. The isolation joint can have a first portion, a second portion, and a bridge portion between the first portion and the second portion. The first and second portions of the isolation joint can each have a seam and a void, while the bridge portion can be solid.

Claims

1. A micro-electromechanical device comprising:

a substrate;

a beam suspended relative to a surface of the substrate, the beam comprising a first beam portion and a second beam portion; and

an isolation joint between the first beam portion and the second beam portion, the isolation joint having a non-linear shape.

2. The micro-electromechanical device according to claim 1, wherein the non-linear shape is an arc shape, an I-shape, or an undulating shape.

3. The micro-electromechanical device according to claim 1, wherein the isolation joint comprises a dielectric material.

4. The micro-electromechanical device according to claim 3, wherein the dielectric material is silicon dioxide.

5. The micro-electromechanical device according to claim 3, wherein the isolation joint further comprises a filler material in a void defined by the dielectric material.

6. The micro-electromechanical device according to claim 5, wherein the filler material is doped or undoped polysilicon.

7. A micro-electromechanical device comprising:

a substrate;

a beam suspended relative to a surface of the substrate, the beam comprising a first beam portion and a second beam portion; and

an isolation joint between the first beam portion and the second beam portion, the isolation joint having a first isolation joint portion, a second isolation joint portion, and a first solid bridge portion, the bridge portion is between the first isolation joint portion and the second isolation joint portion, the first isolation joint portion and the second isolation joint portion each have a seam.

8. The micro-electromechanical device according to claim 7, wherein the first isolation joint portion and the second isolation joint portion each further comprise a void.

9. The micro-electromechanical device according to claim 7, wherein the isolation joint further comprises an additional isolation joint portion having a seam, and an additional solid bridge portion.

10. The micro-electromechanical device according to claim 7, wherein the first bridge portion is adjacent to the first beam portion and the second beam portion.

11. The micro-electromechanical device according to claim 7, wherein the seam of the first isolation joint portion and the seam of the second isolation joint portion are perpendicular to the beam.

12. The micro-electromechanical device according to claim 7, wherein the seam of the first isolation joint portion and the seam of the second isolation joint portion are parallel to the beam.

13. The micro-electromechanical device according to claim 7, wherein the seam of the first isolation joint portion and the seam of the second isolation joint portion have a non-linear shape.

14. The micro-electromechanical device according to claim 13, wherein the non-linear shape is a T-shape.

15. The micro-electromechanical device according to claim 7, wherein each isolation joint portion comprises a dielectric material.

16. The micro-electromechanical device according to claim 15, wherein the dielectric material is silicon dioxide.

17. The micro-electromechanical device according to claim 15, wherein the isolation joint further comprises a filler material in the void of each isolation joint portion.

18. The micro-electromechanical device according to claim 17, wherein the filler material comprises doped or undoped polysilicon.

19. The micro-electromechanical device according to claim 7, wherein the first isolation joint portion and the second isolation joint portion each comprise at least two seams.

20. A method of making a micro-electromechanical device, the method comprising:

forming a non-linear isolation trench in a substrate;

filling the non-linear isolation trench with a dielectric material; and

forming a beam that is suspended relative to a surface of the substrate, the beam comprising a first beam portion on one side of the non-linear isolation trench and a second beam portion on the other side of the non-linear isolation trench.

21. The method of making a micro-electromechanical device according to claim 20, wherein filling the non-linear isolation trench with a dielectric material comprises thermally oxidizing the substrate.

22. The method of making a micro-electromechanical device according to claim 20, wherein the isolation trench has an arc shape, an I-shape, or an undulating shape.

23. The method of making a micro-electromechanical device according to claim 20, further comprising filling a void defined by the dielectric material with a filler material.

24. The method of making a micro-electromechanical device according to claim 23, wherein the filler material is doped or undoped polysilicon.

25. A method of making a micro-electromechanical device, the method comprising:

forming a first isolation trench and a second isolation trench in a substrate;

filling the first isolation trench and the second isolation trench with a dielectric material by thermally oxidizing the substrate, whereby a first portion of the substrate that is between the first isolation trench and the second isolation trench comprises an oxide; and

forming a beam that is suspended relative to a surface of the substrate, the beam having a first beam portion on one side of the first isolation trench and the second isolation trench, and having a second beam portion on the other side of the first isolation trench and the second isolation trench.

26. The method of making a micro-electromechanical device according to claim 25, wherein the first isolation trench and the second isolation trench are perpendicular to the beam.

27. The method of making a micro-electromechanical device according to claim 25, wherein the first isolation trench and the second isolation trench are parallel to the beam.

28. The method of making a micro-electromechanical device according to claim 25, further comprising forming an additional isolation trench in the substrate.

29. The method of making a micro-electromechanical device according to claim 25, wherein the first isolation trench and the second isolation trench have a non-linear shape.

30. The method of making a micro-electromechanical device according to claim 29, wherein the non-linear shape is a T-shape.

31. The method of making a micro-electromechanical device according to claim 25, wherein the portion of the substrate between the first isolation trench and the second isolation trench is adjacent to the first beam portion and to the second beam portion.

32. The method of making a micro-electromechanical device according to claim 25, further comprising filling voids defined by the dielectric material with a filler material.

33. The method of making a micro-electromechanical device according to claim 32, wherein the filler material is doped or undoped polysilicon.

34. A computer-program product comprising a computer-readable storage medium containing instructions that, if executed on a computing device, define a micro-electromechanical device comprising:

a substrate;

a beam suspended relative to a surface of the substrate, the beam comprising a first beam portion and a second beam portion; and

an isolation joint between the first beam portion and the second beam portion, the isolation joint having a non-linear shape.

35. A computer-program product comprising a computer-readable storage medium containing instructions that, if executed on a computing device, define a micro-electromechanical device comprising:

a substrate;

a beam suspended relative to a surface of the substrate, the beam comprising a first beam portion and a second beam portion; and

an isolation joint between the first beam portion and the second beam portion, the isolation joint comprising a first isolation joint portion, a second isolation joint portion, and a solid bridge portion, the bridge portion is between the first isolation joint portion and the second isolation joint portion, the first isolation joint portion and the second isolation joint portion each having a seam.