MEMS Device and Method of Manufacturing a MEMS Device

• US 20190330057A1
• Filed: 07/11/2019
• Published: 10/31/2019
• Est. Priority Date: 10/12/2012
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Dehe, Alfons, Pindl, Stephan, Knott, Bernhard, Ahrens, Carsten
• Granted Patent: US 10,829,368 B2
• Time in Patent Office: Days
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81C 1/00825 Protect against mechanical threats, e.g. against shocks, or residues B81C1/00261 take precedence
• CPC Class Codes: B81C 1/00873 characterised by special arrangements of the devices, allowing an easier separation
• CPC Class Codes: B81C 2201/017 Methods for controlling internal stress of deposited layers not provided for in B81C2201/0164 - B81C2201/0169
• CPC Class Codes: B81C 2201/053 Depositing a protective layers
• CPC Class Codes: H04R 19/005 using semiconductor materials
• 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 31/00 Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor manufacture of microstructural arrangements of deformable or non-deformable structures in general B81C1/00182

Abstract

A method for manufacturing a MEMS device is disclosed. Moreover a MEMS device and a module including a MEMS device are disclosed. An embodiment includes a method for manufacturing MEMS devices includes forming a MEMS stack over a first main surface of a substrate, forming a polymer layer over a second main surface of the substrate and forming a first opening in the polymer layer and the substrate such that the first opening abuts the MEMS stack.

Claims

1. A method for manufacturing microelectromechanical systems (MEMS) devices, the method comprising:

forming a MEMS stack over a first main surface of a substrate;

thinning the substrate to expose a second main surface;

forming an etch stop layer over the second main surface of the substrate;

patterning the etch stop layer to expose portions of the second main surface directly over the MEMS stack;

depositing a polymer layer covering the patterned etch stop layer and the exposed second main surface;

forming a first opening and a second opening in the polymer layer such that the first opening is formed directly over the MEMS stack;

extending the first opening into the substrate without extending the second opening; and

performing a release etch to form moveable components of the MEMS devices.

2. The method according to claim 1, performing the release etch comprises etching with HF based chemistry.

3. The method according to claim 1, wherein the MEMS stack comprises a sacrificial layer disposed between a backplate and a membrane, and wherein the release etch removes all of the sacrificial layer.

4. The method according to claim 1, wherein the MEMS stack comprises a sacrificial layer disposed between a backplate and a membrane, and wherein the release etch removes a substantial portion of the sacrificial layer leaving spacers.

5. The method according to claim 1, wherein the polymer layer is a negative photoresist.

6. The method according to claim 1, wherein the polymer layer is a positive photoresist.

7. The method according to claim 1, further comprising cutting the substrate to form individual MEMS devices without removing the polymer layer.

8. The method according to claim 7, wherein the cutting is aligned with the second opening.

9. A method for manufacturing microelectromechanical systems (MEMS) devices, the method comprising:

forming a MEMS stack over a first main surface of a substrate;

from a major surface that is opposite to the first main surface, thinning the substrate to expose a second main surface;

forming a patterned etch stop layer over the second main surface of the substrate, the patterned etch stop layer comprising openings that expose portions of the second main surface directly over the MEMS stack;

depositing a polymer layer covering the patterned etch stop layer and the exposed portions of the second main surface;

patterning the polymer layer to form a first opening and a second opening in the polymer layer such that the first opening is vertically aligned with the MEMS stack, the first opening exposing regions of the second main surface and the second opening exposing portions of the patterned etch stop layer;

using the patterned etch stop layer and the patterned polymer layer as an etch mask, extending the first opening into the substrate without extending the second opening; and

performing a release etch to form moveable components of the MEMS devices.

10. The method according to claim 9, performing the release etch comprises etching with HF based chemistry.

11. The method according to claim 9, wherein the MEMS stack comprises a sacrificial layer disposed between a backplate and a membrane, and wherein the release etch removes all of the sacrificial layer.

12. The method according to claim 9, wherein the MEMS stack comprises a sacrificial layer disposed between a backplate and a membrane, and wherein the release etch removes a substantial portion of the sacrificial layer leaving spacers.

13. The method according to claim 9, wherein the polymer layer is a negative photoresist.

14. The method according to claim 9, wherein the polymer layer is a positive photoresist.

15. The method according to claim 9, further comprising cutting the substrate to form individual MEMS devices without removing the polymer layer.

16. The method according to claim 15, wherein the cutting is aligned with the second opening.

17. A method for manufacturing microelectromechanical systems (MEMS) devices, the method comprising:

forming a MEMS stack over a first main surface of a substrate, the MEMS stack comprising a first side mounted to the first main surface and an opposite second side facing away from the first main surface;

from a major surface that is opposite to the first main surface, thinning the substrate to expose a second main surface;

attaching a support substrate to the second side of the MEMS stack;

flipping the support substrate;

forming a patterned etch stop layer over the second main surface of the substrate, the patterned etch stop layer comprising openings that expose portions of the second main surface directly over the MEMS stack;

depositing a polymer layer covering the patterned etch stop layer and the exposed portions of the second main surface;

patterning the polymer layer to form a first opening and a second opening in the polymer layer such that the first opening is vertically aligned with the MEMS stack, the first opening exposing regions of the second main surface and the second opening exposing portions of the patterned etch stop layer;

using the patterned etch stop layer and the patterned polymer layer as an etch mask, extending the first opening into the substrate without extending the second opening;

removing the support substrate; and

after removing the support substrate, performing a release etch to form moveable components of the MEMS devices; and

dicing the substrate through the second opening to form individual MEMS devices.

18. The method according to claim 17, wherein the MEMS stack comprises a sacrificial layer disposed between a backplate and a membrane, and wherein the release etch removes all of the sacrificial layer.

19. The method according to claim 17, wherein the MEMS stack comprises a sacrificial layer disposed between a backplate and a membrane, and wherein the release etch removes a substantial portion of the sacrificial layer leaving spacers.

20. The method according to claim 17, wherein the dicing is performed without removing the polymer layer.