MICRO-ELECTRO-MECHANICAL SYSTEMS (MEMS) DEVICE AND METHOD FOR FABRICATING THE MEMS

• US 20180115836A1
• Filed: 10/26/2016
• Published: 04/26/2018
• 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
• Granted Patent: US 10,250,998 B2
• Time in Patent Office: 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 on the substrate, having a dielectric opening corresponding to the substrate opening to form the diaphragm region;

a diaphragm, within the dielectric opening, held by the dielectric supporting layer at a periphery; and

a backplate, disposed on the dielectric supporting layer, having a plurality of venting holes, connecting to the dielectric opening, wherein the 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.

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

3. The MEMS device of claim 1, wherein the conductive layer of the 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 backplate.

5. The MEMS device of claim 4, wherein the conductive layer of the 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. A Micro-Electro-Mechanical Systems (MEMS) device, comprising:

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

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

a diaphragm, within the dielectric opening, held by the dielectric supporting layer at a periphery; and

a backplate, disposed on the dielectric supporting layer, having a plurality of venting holes, connecting to the dielectric opening, wherein the backplate comprises a conductive layer and a passivation layer covered by the conductive layer at a side opposite to the diaphragm, wherein the passivation layer has a central portion and a peripheral portion, the central portion is corresponding to the diaphragm region to provide an anti-sticky structure and the peripheral portion is on the dielectric supporting layer and covered by a peripheral portion of the conductive layer.

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

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

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

a diaphragm, held by the dielectric supporting layer at a periphery;

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 within the dielectric opening is facing to the diaphragm and not covered by the passivation layer; and

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.

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

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

11. The MEMS device of claim 10, 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.

12. The MEMS device of claim 8, 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.

13. The MEMS device of claim 8, 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.

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

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

16. The MEMS device of claim 8, 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.

17. The MEMS device of claim 8, 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.

18. The MEMS device of claim 8, 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.

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

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

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

a diaphragm, held by the dielectric supporting layer at a periphery;

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 covered by the conductive layer at a side opposite to the diaphragm, wherein the passivation layer has a central portion and a peripheral portion, the central portion is corresponding to the diaphragm region to provide an anti-sticky structure and the peripheral portion is on the dielectric supporting layer and covered by a peripheral portion of the conductive layer; and

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.

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

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

a diaphragm, held by the dielectric supporting layer at a periphery;

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

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 is just a passivation layer; and

a second backplate, between the diaphragm and the substrate, 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.

21. The MEMS device of claim 20, wherein a first anti-sticky structure is either on the first backplate or the diaphragm between the diaphragm and the first backplate, and a second anti-sticky structure is either on the second backplate or the diaphragm between the diaphragm and the second backplate.

22. A method for fabricating a Micro-Electro-Mechanical Systems (MEMS) device on a substrate, comprising:

forming a dielectric supporting layer on the substrate, wherein the dielectric supporting layer is embedded with a diaphragm;

forming a first backplate on the dielectric supporting layer, wherein the first backplate has been patterned to have a plurality of venting holes with a diaphragm region as predetermined, wherein the first backplate comprises a conductive layer on the dielectric supporting layer and a passivation layer covering over the conductive layer;

patterning the substrate from a side opposite to the dielectric supporting layer, to form a substrate opening to expose the dielectric supporting layer; and

performing an isotropic etching process, to remove a portion of dielectric material of the dielectric supporting layer through the venting holes and the substrate opening, so that the dielectric supporting layer has a dielectric opening to expose the diaphragm within the diaphragm region.

23. The method of claim 22, further comprising:

forming a first anti-sticky structure either on the first backplate or the diaphragm between the diaphragm and the first backplate embedded in the dielectric supporting layer,

wherein the first anti-sticky structure is exposed in the step of performing the isotropic etching process.

24. The method of claim 23, further comprising:

forming a second backplate embedded in the dielectric supporting layer between the substrate and the diaphragm, wherein the second backplate has a plurality of second venting holes,

wherein the step of performing the isotropic etching process etches the dielectric material also through the second venting holes.

25. The method of claim 24, further comprising:

forming a second anti-sticky structure either on the second backplate or the diaphragm between the diaphragm and the first backplate embedded in the dielectric supporting layer,

wherein the second anti-sticky structure is exposed in the step of performing the isotropic etching process.

26. A method for fabricating a Micro-Electro-Mechanical Systems (MEMS) device on a substrate, comprising:

forming a dielectric supporting layer on the substrate, wherein the dielectric supporting layer is embedded with a diaphragm;

forming a first backplate on the dielectric supporting layer, wherein the first backplate has been patterned to have a plurality of venting holes with a diaphragm region as predetermined, wherein the first backplate is just a passivation layer;

patterning the substrate from a side opposite to the dielectric supporting layer, to form a substrate opening to expose the dielectric supporting layer; and

performing an isotropic etching process, to remove a portion of dielectric material of the dielectric supporting layer through the venting holes and the substrate opening, so that the dielectric supporting layer has a dielectric opening to expose the diaphragm within the diaphragm region.

27. The method of claim 26, further comprising:

forming a first anti-sticky structure either on the first backplate or the diaphragm between the diaphragm and the first backplate embedded in the dielectric supporting layer,

wherein the first anti-sticky structure is exposed in the step of performing the isotropic etching process.

28. The method of claim 27, further comprising:

forming a second backplate embedded in the dielectric supporting layer between the substrate and the diaphragm, wherein the second backplate has a plurality of second venting holes,

wherein the step of performing the isotropic etching process etches the dielectric material also through the second venting holes.

29. The method of claim 28, further comprising:

forming a second anti-sticky structure either on the second backplate or the diaphragm between the diaphragm and the second backplate embedded in the dielectric supporting layer,

wherein the second anti-sticky structure is exposed in the step of performing the isotropic etching process.

30. A method for fabricating a Micro-Electro-Mechanical Systems (MEMS) device on a substrate, comprising:

forming a dielectric supporting layer on the substrate, wherein the dielectric supporting layer is embedded with a diaphragm, wherein the diaphragm is patterned to have a plurality of indents distributed along a peripheral region;

forming a first backplate on the dielectric supporting layer, wherein the first backplate has been patterned to have a plurality of venting holes with a diaphragm region as predetermined, wherein the first backplate comprises a conductive layer on the dielectric supporting layer and a passivation layer covering over the conductive layer;

patterning the substrate from a side opposite to the dielectric supporting layer, to form a substrate opening to expose the dielectric supporting layer; and

performing an isotropic etching process, to remove a portion of dielectric material of the dielectric supporting layer through the venting holes and the substrate opening, so that the dielectric supporting layer has a dielectric opening to expose the diaphragm within the diaphragm region,

wherein the dielectric opening also exposes an inner portion of each of the indents of the diaphragm.

31. The method of claim 30, further comprising:

forming a first anti-sticky structure either on the first backplate or the diaphragm between he diaphragm and the first backplate embedded in the dielectric supporting layer,

wherein the first anti-sticky structure is exposed in the step of performing the isotropic etching process.

32. The method of claim 31, further comprising:

forming a second backplate embedded in the dielectric supporting layer between the substrate and the diaphragm, wherein the second backplate has a plurality of second venting holes,

wherein the step of performing the isotropic etching process etches the dielectric material also through the second venting holes.

33. The method of claim 32, further comprising:

forming a second anti-sticky structure either on the second backplate or the diaphragm between the diaphragm and the second backplate embedded in the dielectric supporting layer,

wherein the second anti-sticky structure is exposed in the step of performing the isotropic etching process.

34. A method for fabricating a Micro-Electro-Mechanical Systems (MEMS) device on a substrate, comprising:

forming a dielectric supporting layer on the substrate, wherein the dielectric supporting layer is embedded with a diaphragm;

forming a first backplate on the dielectric supporting layer, wherein the backplate has been patterned to have a plurality of venting holes with a diaphragm region as predetermined, wherein the backplate comprises a conductive layer on the dielectric supporting layer and a passivation layer covering over the conductive layer, wherein the passivation layer of the first backplate comprises a peripheral portion which surrounds a peripheral portion of the conductive layer to be held by the dielectric supporting layer at an end state;

patterning the substrate from a side opposite to the dielectric supporting layer, to form a substrate opening to expose the dielectric supporting layer; and

performing an isotropic etching process, to remove a portion of dielectric material of the dielectric supporting layer through the venting holes and the substrate opening, so that the dielectric supporting layer has a dielectric opening to expose the diaphragm within the diaphragm region,

wherein the dielectric opening also exposes an inner portion of each of the indents of the diaphragm.

35. The method of claim 34, further comprising:

forming a first anti-sticky structure either on the first backplate or the diaphragm between the diaphragm and the first backplate embedded in the dielectric supporting layer,

wherein the first anti-sticky structure is exposed in the step of performing the isotropic etching process.

36. The method of claim 35, further comprising:

forming a second backplate embedded in the dielectric supporting layer between the substrate and the diaphragm, wherein the second backplate has a plurality of second venting holes,

wherein the step of performing the isotropic etching process etches the dielectric material also through the second venting holes.

37. The method of claim 36, further comprising:

forming a second anti-sticky structure either on the second backplate or the diaphragm between the diaphragm and the second backplate embedded in the dielectric supporting layer,

wherein the second anti-sticky structure is exposed in the step of performing the isotropic etching process.