Micro-electro-mechanical systems (MEMS) device and method for fabricating the MEMS

• US 10,250,998 B2
• Filed: 10/26/2016
• Issued: 04/02/2019
• Est. Priority Date: 10/26/2016
• Status: Active Grant

• Current Assignee: Solid State System Co., Ltd.
• Original Assignee: Solid State System Co., Ltd.
• Inventors: Hsieh, Tsung-Min, Lee, Chien-Hsing, Tsai, Cheng-Wei
• Primary Examiner(s): Etesam, Amir H
• Application Number:
  US15/335,420
• Publication Number:
  US 20180115836A1
• Time in Patent Office: 888 Days
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2203/0127 Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function
• CPC Class Codes: B81B 3/001 Structures having a reduced contact area, e.g. with bumps or with a textured surface
• CPC Class Codes: B81B 3/007 For controlling stiffness, e.g. ribs
• CPC Class Codes: B81C 1/00984 Methods for avoiding stiction when the device is in use not provided for in groups B81C1/00968 - B81C1/00976
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 2201/003 Mems transducers or their use of the electrostatic type H04R19/005
• CPC Class Codes: H04R 31/003 for diaphragms or their outer suspension

Abstract

A Micro-Electro-Mechanical Systems (MEMS) device includes a substrate, a dielectric supporting layer, a diaphragm, a backplate. The substrate has a substrate opening corresponding to a diaphragm region. The dielectric supporting layer is disposed on the substrate, having a dielectric opening corresponding to the substrate opening to form the diaphragm region. The diaphragm within the dielectric opening is held by the dielectric supporting layer at a periphery. The backplate is disposed on the dielectric supporting layer, having a plurality of venting holes, connecting to the dielectric opening. The backplate includes a conductive layer and a passivation layer covering over the conductive layer at a first side opposite to the diaphragm, wherein a second side of the conductive layer is facing to the diaphragm and not covered by the passivation layer.

Claims

1. A Micro-Electro-Mechanical Systems (MEMS) device, comprising:

a substrate, having a substrate opening corresponding to a diaphragm region;

a dielectric supporting layer, disposed directly on the substrate, having a dielectric opening corresponding to the substrate opening to form the diaphragm region;

a diaphragm, within the dielectric opening, wherein a periphery of the diaphragm is embedded into the dielectric supporting layer; and

a first backplate, disposed on the dielectric supporting layer, having a plurality of first venting holes, connecting to the dielectric opening, wherein the first backplate comprises a conductive layer and a passivation layer covering over the conductive layer at a first side opposite to the diaphragm, wherein a second side of the conductive layer is facing to the diaphragm and not covered by the passivation layer,

wherein the dielectric supporting layer is disposed in between the first backplate and the substrate, and wherein a periphery portion of the conductive layer of the first backplate is disposed on the dielectric supporting layer.

2. The MEMS device of claim 1, further comprising an anti-sticky structure on the second surface of the conductive layer of the first backplate.

3. The MEMS device of claim 1, wherein the conductive layer of the first backplate comprises an anti-sticky structure, protruding from the second surface.

4. The MEMS device of claim 1, wherein the diaphragm comprises an anti-sticky structure, protruding toward the first backplate.

5. The MEMS device of claim 4, wherein the conductive layer of the first backplate comprises an additional anti-sticky structure, protruding from the second surface and corresponding to the anti-sticky structure of the diaphragm.

6. The MEMS device of claim 1, wherein the diaphragm comprises a plurality of the indent portions distributed at the periphery, wherein the dielectric opening exposes an inner part of each of the indent portions.

7. MEMS device of claim 1, further comprising:

a second backplate, between the substrate and the diaphragm, held by the dielectric supporting layer at a periphery, having a plurality of second venting holes, connecting between the substrate opening and the dielectric opening.

8. The MEMS device of claim 7, wherein the conductive layer of the first backplate also comprises a first anti-sticky structure on the second surface.

9. The MEMS device of claim 8, further comprising a second anti-sticky structure on the second backplate, respectively protruding toward the first anti-sticky structure.

10. The MEMS device of claim 9, wherein the second backplate comprises a stack of a conductive layer and a dielectric layer, wherein the dielectric layer is facing to the diaphragm and the second anti-sticky structure is formed from the dielectric layer.

11. The MEMS device of claim 7, wherein the passivation layer of the first backplate comprises a peripheral portion which surrounds a peripheral portion of the conductive layer being held by the dielectric supporting layer.

12. The MEMS device of claim 7, wherein the conductive layer of the first backplate comprises a first anti-sticky structure, protruding from the second surface, wherein the diaphragm further comprises a second anti-sticky structure, protruding toward the second backplate.

13. The MEMS device of claim 12, wherein the passivation layer of the first backplate comprises a first anti-sticky structure on the second side of the conductive layer.

14. The MEMS device of claim 13, wherein the diaphragm comprises a second anti-sticky structure protruding toward the first backplate.

15. The MEMS device of claim 7, wherein the diaphragm having a first surface and second surface comprises a first anti-sticky structure protruding from the first surface toward the first backplate and a second anti-sticky structure protruding from the second surface toward the second backplate.

16. The MEMS device of claim 7, wherein the conductive layer of the first backplate comprises a first anti-sticky structure, protruding toward the diaphragm and the diaphragm has a second anti-sticky structure, protruding toward second backplate.

17. The MEMS device of claim 7, wherein the diaphragm comprises a plurality of the indent portions distributed at the periphery, wherein the dielectric opening exposes an inner part of each of the indent portions.