MEMS microphone device and method for making same

• US 20120261775A1
• Filed: 07/06/2011
• Published: 10/18/2012
• Est. Priority Date: 04/12/2011
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Wang, Chuan-Wei, Sun, Chih-Ming
• Granted Patent: US 8,524,519 B2
• Time in Patent Office: Days
• US Class Current: 257/416
• CPC Class Codes: B81B 7/0051 between the package lid and the substrate
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence

Abstract

The present invention discloses a MEMS microphone device and its manufacturing method. The MEMS microphone device includes: a substrate including a first cavity; a MEMS device region above the substrate, wherein the MEMS device region includes a metal layer, a via layer, an insulating material region and a second cavity; a mask layer above the MEMS device region; a first lid having at least one opening communicating with the second cavity, the first lid being fixed above the mask layer; and a second lid fixed under the substrate.

Claims

1. A method for manufacturing a MEMS microphone device, comprising:

providing a substrate;

forming at least one metal layer, at least one via layer and an insulating material region above the substrate, the at least one metal layer including a top metal layer;

forming a mask layer above the top metal layer;

removing a portion of the mask layer to expose a portion of the insulating material region;

fixing a first lid above the mask layer, the first lid having at least one opening;

etching the backside of the substrate to form a first cavity;

fixing a second lid under the substrate; and

removing a portion of the insulating material region to form a second cavity, wherein the second cavity communicates with the first cavity and the at least one opening, and wherein the second cavity, the at least one metal layer, the at least one via layer, and the insulating material region together form a MEMS device region.

2. The method of claim 1, further comprising:

forming an adhesion layer between the first lid and the mask layer for fixing the first lid.

3. The method of claim 1, wherein the step of etching the backside of the substrate to form a first cavity includes etching the backside of the substrate by inductively coupled plasma (ICP).

4. The method of claim 1, wherein the step of fixing a first lid having at least one opening above the mask layer includes:

forming an etch stop layer under the first lid; and

etching the first lid to form the at least one opening.

5. The method of claim 4, further comprising:

removing the etch stop layer by HF vapor.

6. The method of claim 1, wherein the step of fixing a first lid having at least one opening above the mask layer includes fixing the first lid by means of eutectic, glass frit, epoxy or solder.

7. The method of claim 1, wherein the step of fixing a second lid under the substrate includes fixing the second lid by means of eutectic, glass frit, epoxy or solder.

8. The method of claim 1, further comprising:

forming at least one wire for transmitting signals from the MEMS device region to the outside of the MEMS microphone device.

9. The method of claim 8, wherein the step of forming at least one wire for transmitting signals from the MEMS device region to the outside of the MEMS microphone includes providing the at least one wire through the substrate and the second lid by a through-silicon via (TSV) process or a T-contact process.

10. The method of claim 1, wherein the step of removing a portion of the insulating material region to form a second cavity includes etching the insulating material region by HF vapor.

11. A MEMS microphone device, comprising:

a substrate including a first cavity;

a MEMS device region above the substrate, wherein the MEMS device region includes at least one metal layer, at least one via layer, an insulating material region and a second cavity;

a mask layer above the MEMS device region;

a first lid having at least one opening communicating with the second cavity, the first lid being fixed above the mask layer; and

a second lid fixed under the substrate.

12. The MEMS microphone device of claim 11, further comprising:

an adhesion layer between the first lid and the MEMS device region.

13. The MEMS microphone device of claim 11, wherein the first lid is formed by a silicon wafer.

14. The MEMS microphone device of claim 11, wherein the second lid is formed by a silicon wafer.

15. The MEMS microphone device of claim 11, further comprising:

at least one wire for transmitting signals from the MEMS device region to the outside of the MEMS microphone device.

16. The MEMS microphone device of claim 15, wherein the at least one wire goes through the substrate and the second lid.

17. The MEMS microphone device of claim 15, wherein the at least one wire follows a path along a lateral side of the substrate and extends to a bottom surface of the second lid.