MEMS isolation structures

• US 9,352,962 B2
• Filed: 11/15/2010
• Issued: 05/31/2016
• Est. Priority Date: 11/15/2010
• Status: Active Grant

• Current Assignee: DigitalOptics Corporation MEMS (Adeia Inc.)
• Original Assignee: DigitalOptics Corporation MEMS (Adeia Inc.)
• Inventors: Jain, Ankur, Gutierrez, Roman C., Lee, Shi-Sheng, Calvet, Robert J., Liu, Xiaolei
• Primary Examiner(s): Lee, Jae
• Application Number:
  US12/946,430
• Publication Number:
  US 20120119324A1
• Time in Patent Office: 2,024 Days
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/031 Thermal actuators
• CPC Class Codes: B81B 2203/033 Trenches
• CPC Class Codes: B81B 7/0077 Other packages not provided for in groups B81B7/0035 - B81B7/0074
• CPC Class Codes: B81C 1/00571 Avoid or control under-cutting
• CPC Class Codes: G03B 2205/0061 using piezoelectric actuators
• CPC Class Codes: G03B 3/10 Power-operated focusing

Abstract

A device may comprise a substrate formed of a first semiconductor material and a trench formed in the substrate. A second semiconductor material may be formed in the trench. The second semiconductor material may have first and second portions that are isolated with respect to one another and that are isolated with respect to the first semiconductor material.

Claims

1. A device comprising:

a substrate formed of a first material;

a trench formed in the substrate;

a second material formed in the trench, the second material having first and second portions formed in the trench, wherein the first and second portions are electrically isolated with respect to one another and electrically isolated with respect to the first material, and

an electrically insulating material disposed between the first and second portions and between the substrate and the second material.

2. The device as recited in claim 1, wherein the first and second portions are mechanically isolated with respect to one another and are mechanically isolated with respect to the first material.

3. The device as recited in claim 1, wherein the first and second materials are different materials with respect to one another, wherein the electrically insulating material comprises an oxide material, and wherein the oxide material fills an additional gap between the first material and the second material.

4. The device as recited in claim 1, further comprising a pinch formed in the trench to facilitate isolation of the first and second portions of the second material.

5. The device as recited in claim 4, wherein the pinch is defined by a narrowing of the trench.

6. The device as recited in claim 1, wherein the trench becomes more narrow from a top of the substrate to a bottom of the substrate.

7. The device as recited in claim 1, wherein the second material extends over at least a portion of a top of the first material.

8. The device as recited in claim 1, wherein the first material comprises single crystalline silicon and the second material comprises polysilicon.

9. An electronic device comprising the device of claim 1.

10. A system comprising:

an actuator device having a substrate formed of a first material;

a trench formed in the substrate;

a second material formed in the trench, the second material having first and second portions formed in the trench, wherein the first and second portions are electrically isolated with respect to one another and electrically isolated with respect to the first material; and

an electrically insulating material disposed between the first and second portions and between the substrate and the second material.

11. The system as recited in claim 10, wherein the first and second portions are mechanically isolated with respect to one another and are mechanically isolated with respect to the first material.

12. The system as recited in claim 11, wherein the first and second portions are adapted to move with respect to one another during actuation of the actuator device.

13. The system as recited in claim 10, wherein the first and second materials are different materials with respect to one another, wherein the electrically insulating material comprises an oxide material, and wherein the oxide material fills an additional gap between the first material and the second material.

14. The system as recited in claim 13, wherein the first and second portions are adapted to communicate different voltages during actuation of the actuator device.

15. The system as recited in claim 10, further comprising a pinch formed in the trench to facilitate isolation of the first and second portions of the second material.

16. The system as recited in claim 15, wherein the pinch is defined by a narrowing of the trench.

17. The system as recited in claim 10, wherein the trench tapers from a top of the substrate to a bottom of the substrate.

18. The system as recited in claim 10, wherein the second material extends over at least a portion of a top of the first material.

19. The system as recited in claim 10, wherein the first material comprises single crystalline silicon and the second comprises polysilicon.

20. An electronic device comprising the system of claim 10.

21. A method comprising:

forming a trench in a substrate of a first material;

forming an isolating layer in the trench; and

forming a second material upon the isolating layer such that the second material has two portions that are formed in the trench and are electrically isolated with respect to one another and electrically isolated with respect to the first material by the isolating layer, wherein the isolating layer is permanently disposed between the first material and the second material.

22. The method as recited in claim 21, wherein the first and the second materials are different materials with respect to one another and wherein the isolating layer is an oxide.

23. The method as recited in claim 22, further comprising forming a pinch in the trench such that the isolating layer separates the two portions of the second material.

24. The method as recited in claim 22, further comprising etching the second material to isolate the two portions with respect to one another.

25. A method comprising:

moving a moving portion of a MEMS actuator formed of a first material with respect to a fixed portion of the MEMS actuator; and

wherein the moving portion is electrically isolated with respect to the fixed portion via a separation in a different second material formed in a trench and wherein the separation comprises an oxide material that is permanently disposed between first and second portions of the different second material, which are formed in the trench, and between the substrate and the different second material.

26. The method as recited in claim 25, further comprising applying a voltage to the moving portion and applying a different voltage to the fixed portion.

27. The method as recited in claim 25, wherein the first material and the second material are conductors or semiconductors.