Forming an oxide MEMS beam

• US 8,138,008 B1
• Filed: 11/29/2010
• Issued: 03/20/2012
• Est. Priority Date: 11/29/2010
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Stamper, Anthony K., Hasselbach, Joseph P., Lestage, Karen L.
• Primary Examiner(s): Coleman, William D
• Application Number:
  US12/955,224
• Time in Patent Office: 477 Days
• Field of Search: 438/52
• US Class Current: 438/52
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81C 1/00111 Tips, pillars, i.e. raised structures microneedles A61M37/0015
• CPC Class Codes: B81C 1/00666 Treatments for controlling internal stress or strain in MEMS structures

Abstract

Solutions for forming a semiconductor including an oxide MEMS beam are disclosed. In one embodiment, a method of forming a beam within a sealed cavity includes: depositing a lower insulator layer comprising one or more layers; depositing an upper insulator layer over the first insulator layer, the upper insulator layer comprising one or more layers, wherein a composite stress of the upper insulator layer is different than a composite stress of the lower insulator layer.

Claims

1. A method of forming a beam within a sealed cavity, the method comprising:

depositing a lower insulator layer comprising one or more layers;

depositing an upper insulator layer over the first insulator layer, the upper insulator layer comprising one or more layers, wherein a composite stress of the upper insulator layer is different than a composite stress of the lower insulator layer;

forming a first conductor layer below the lower insulator layer and a second conductor layer above the upper insulator layer, wherein each conductor layer comprises one or more metal layers; and

forming a stabilizing insulator layer between at least one of;

the upper insulator layer and the second conductor or the first conductor and the lower insulator layer, wherein the at least one of the upper insulator layer or the lower insulator layer includes an unstable stress when exposed to ambient.

2. The method of claim 1, wherein the composite stress of the upper insulator layer is more tensile or less compressive than the composite stress of the lower insulator layer, such that the beam bends downward.

3. The method of claim 1, wherein the composite stress of the lower insulator layer is more tensile or less compressive than the composite stress of the upper insulator layer, such that the beam bends upward.

4. The method of claim 1, further comprising forming a conductive via through the upper insulator layer and the lower insulator layer, wherein the conductive via electrically connects the upper conductor layer and the lower conductor layer.

5. The method of claim 1, wherein the stabilizing insulator layer includes a stable compressive stress.

6. The method of claim 1, wherein the lower insulator layer, the upper insulator layer, and the stabilizing insulator layer include silicon dioxide.

7. The method of claim 1, wherein the stabilizing insulator layer is at least approximately 50 nanometers thick.

8. A method of forming a beam within a sealed cavity, the method comprising:

depositing a first stabilizing insulator layer;

depositing an insulator layer above the first stabilizing insulator layer, the insulator layer including an unstable stress when exposed to ambient; and

depositing a second stabilizing insulator layer above the insulator layer, wherein the first stabilizing insulator layer and the second stabilizing insulator layer include a stable stress when exposed to ambient.

9. The method of claim 8, wherein at least one of:

the first stabilizing insulator layer, the insulator layer, or the second stabilizing insulator layers include one or more layers.

10. The method of claim 8, further comprising forming a first conductor layer below the first stabilizing insulator layer and a second conductor layer above the second stabilizing insulator layer, wherein each conductor layer comprises one or more metal layers.

11. The method of claim 8, wherein the first stabilizing insulator layer and the second stabilizing insulator layer include a stable compressive stress.

12. The method of claim 8, wherein the first stabilizing insulator layer, the insulator layer, and the second stabilizing insulator layer include silicon dioxide.

13. The method of claim 8, wherein depositing the first stabilizing insulator layer and the second stabilizing insulator layer includes using a TEOS-based plasma enhanced chemical vapor deposition (PECVD) process.

14. The method of claim 8, wherein depositing the insulator layer includes using a silane-based plasma enhanced chemical vapor deposition (PECVD) process.

15. The method of claim 8, wherein the first stabilizing insulator layer and the second stabilizing insulator layer are at least approximately 50 nanometers thick.

16. The method of claim 10, further comprising forming a conductive via through the insulator layer, wherein the conductive via electrically connects the upper conductor layer and the lower conductor layer.

17. The method of claim 11, wherein the insulator layer includes an unstable tensile stress.

18. A method of forming a beam within a sealed cavity, the method comprising:

forming a lower conductor layer comprising one or more metal layers;

depositing an insulator layer above the lower conductor layer; and

forming an upper conductor layer above the insulator layer, the upper conductor layer comprising one or more metal layers, wherein at least one of;

a stress, a thickness, or a pattern factor of the upper conductor layer is different than a stress, a thickness, or a pattern factor of the lower conductor layer.

19. The method of claim 18, further comprising forming a conductive via through the insulator layer, wherein the conductive via electrically connects the upper conductor layer and the lower conductor layer.

20. The method of claim 18, wherein the stress of the upper conductor layer is more tensile or less compressive than the stress of the lower conductor layer, such that the beam bends downward.

21. The method of claim 18, wherein the stress of the upper conductor layer is less tensile or more compressive than the stress of the lower conductor layer, such that the beam bends upward.

22. The method of claim 18, wherein the insulator layer includes silicon dioxide.