MEMS Device with Release Aperture

• US 20140287548A1
• Filed: 03/26/2014
• Published: 09/25/2014
• Est. Priority Date: 10/21/2010
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Lin, Chung-Hsien, Chu, Chia-Hua, Cheng, Chun-Wen
• Granted Patent: US 8,962,367 B2
• Time in Patent Office: Days
• US Class Current: 438/50
• CPC Class Codes: B81B 7/0058 for protecting against damages due to external chemical or mechanical influences, e.g. shocks or vibrations
• CPC Class Codes: B81C 1/00333 Aspects relating to packaging of MEMS devices, not covered by groups B81C1/00269 - B81C1/00325
• CPC Class Codes: B81C 1/0038 Processes for creating layers of materials not provided for in groups B81C1/00357 - B81C1/00373
• CPC Class Codes: B81C 2203/0136 Growing or depositing of a covering layer
• CPC Class Codes: B81C 2203/0145 Hermetically sealing an opening in the lid
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

The present disclosure provides a method of fabricating a micro-electro-mechanical systems (MEMS) device. In an embodiment, a method includes providing a substrate including a first sacrificial layer, forming a micro-electro-mechanical systems (MEMS) structure above the first sacrificial layer, and forming a release aperture at substantially a same level above the first sacrificial layer as the MEMS structure. The method further includes forming a second sacrificial layer above the MEMS structure and within the release aperture, and forming a first cap over the second sacrificial layer and the MEMS structure, wherein a leg of the first cap is disposed between the MEMS structure and the release aperture. The method further includes removing the first sacrificial layer, removing the second sacrificial layer through the release aperture, and plugging the release aperture. A MEMS device formed by such a method is also provided.

Claims

1. A method, comprising:

providing a substrate including a first sacrificial layer;

forming a micro-electro-mechanical systems (MEMS) structure above the first sacrificial layer;

forming a first release aperture at substantially a same level above the first sacrificial layer as the MEMS structure;

forming a second sacrificial layer above the MEMS structure and within the first release aperture;

forming a first cap over the second sacrificial layer and the MEMS structure, a leg of the first cap disposed between the MEMS structure and a second release aperture above the first release aperture;

removing the first and second sacrificial layers through the first and second release apertures; and

plugging the second release aperture.

2. The method of claim 1, wherein the second release aperture is formed to have a diameter of less than 1.5 microns.

3. The method of claim 1, further comprising patterning the second sacrificial layer to form trenches over the MEMS structure.

4. The method of claim 3, further comprising depositing a dielectric layer in the trenches and the first release aperture.

5. The method of claim 4, further comprising forming top electrodes over the dielectric layer and second sacrificial layer.

6. The method of claim 1, further comprising forming a reinforcement layer over the MEMS structure.

7. The method of claim 6, further comprising forming a passivation layer over the reinforcement layer.

8. The method of claim 1, wherein the second release aperture is plugged with a second cap and the second cap plugs both the first and second release apertures.

9. The method of claim 1, further comprising forming a bottom electrode below the MEMS structure.

16. The method of claim 1, wherein the second release aperture is plugged with a second cap and the second cap plugs both the first and second release apertures.

10. A method, comprising:

forming a first sacrificial layer;

forming a micro-electro-mechanical systems (MEMS) structure above the first sacrificial layer;

forming a first release aperture;

forming a second sacrificial layer above the MEMS structure and within the first release aperture;

forming a second release aperture above the first release aperture;

forming a first cap over the second sacrificial layer and the MEMS structure, a leg of the first cap disposed between the MEMS structure and the second release aperture;

removing the first and second sacrificial layers through the first and second release apertures; and

plugging the second release aperture.

11. The method of claim 10, wherein the second release aperture is formed to have a diameter of less than 1.5 microns.

12. The method of claim 10, further comprising patterning the second sacrificial layer to form trenches over the MEMS structure.

13. The method of claim 12, further comprising depositing a dielectric layer in the trenches and the first release aperture.

14. The method of claim 10, further comprising forming a bottom electrode and a top electrode below and above the MEMS structure, respectively.

15. The method of claim 10, further comprising forming a reinforcement layer over the MEMS structure and a passivation layer over the reinforcement layer.

17. A method, comprising:

providing a substrate including a bottom electrode and a first sacrificial layer above the bottom electrode;

forming a micro-electro-mechanical systems (MEMS) structure and a first release aperture set apart from the MEMS structure, the MEMS structure and the first release aperture disposed at substantially a same level above the first sacrificial layer;

forming a second sacrificial layer over the MEMS structure and within the first release aperture;

forming a top electrode above the second sacrificial layer;

forming a first cap over the top electrode, the second sacrificial layer, and the MEMS structure, a leg of the first cap disposed between the MEMS structure and a second release aperture above the first release aperture;

removing the first and second sacrificial layers through the first and second release apertures; and

plugging the second release aperture with a second cap.

18. The method of claim 17, wherein the second release aperture is formed to have a diameter between about 0.5 micron and about 2 micron.

19. The method of claim 17, further comprising forming a reinforcement layer over the MEMS structure and a passivation layer over the reinforcement layer and the second cap.

20. The method of claim 17, further comprising plugging the first release aperture and the second release aperture with the second cap.