Support Structure for TSV in MEMS Structure

• US 20130181355A1
• Filed: 05/14/2012
• Published: 07/18/2013
• Est. Priority Date: 01/16/2012
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Tsai, Yi Heng, Chang, Kuei-Sung, Tsai, Hung-Chia
• Granted Patent: US 9,085,456 B2
• Time in Patent Office: Days
• US Class Current: 257/774
• CPC Class Codes: B81B 7/007 Interconnections between the MEMS and external electrical signals
• CPC Class Codes: B81C 1/0023 Packaging together an electronic processing unit die and a micromechanical structure die MEMS packages B81B7/0032; MEMS packaging processes B81C1/00261
• CPC Class Codes: B81C 1/00238 Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure
• CPC Class Codes: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: B81C 2203/0792 Forming interconnections between the electronic processing unit and the micromechanical structure

Abstract

An embodiment is a method for forming a microelectromechanical system (MEMS) device. The method comprises forming a MEMS structure over a first substrate, wherein the MEMS structures comprises a movable element; forming a bonding structure over the first substrate; and forming a support structure over the first substrate, wherein the support structure protrudes from the bonding structure. The method further comprises bonding the MEMS structure to a second substrate; and forming a through substrate via (TSV) on a backside of the second substrate, wherein the overlying TSV is aligned with the bonding structure and the support structure.

Claims

1. A method for forming a microelectromechanical system (MEMS) device comprising:

forming a MEMS structure over a first substrate, wherein the MEMS structure comprises a movable element;

forming a bonding structure over the first substrate;

forming a support structure over the first substrate, wherein the support structure laterally protrudes from the bonding structure;

bonding the MEMS structure to a second substrate; and

forming a through substrate via (TSV) on a backside of the second substrate, wherein the overlying TSV is aligned with the bonding structure and the support structure.

2. The method of claim 1, wherein the bonding structure and the support structure comprise a same material.

3. The method of claim 1, wherein the support structure surrounds a projection of the overlying TSV by a width from about 1 um to about 20 um.

4. The method of claim 1, wherein the forming the bonding structure is at a same time and by a same process as the forming the support structure.

5. The method of claim 1, wherein the forming the support structure comprises:

depositing a first material on the MEMS structure;

patterning the first material;

depositing a second material over the second substrate; and

patterning the second material.

6. The method of claim 1, wherein the forming the support structure comprises depositing a first material on the MEMS structure and patterning the first material.

7. The method of claim 1, wherein the forming the MEMS structure further comprises:

depositing a first dielectric layer on the first substrate;

etching a recess in the first dielectric layer;

fusion bonding a wafer on the first dielectric layer; and

etching the wafer to form the movable element.

8. The method of claim 1, wherein the forming the MEMS structure further comprises:

etching a recess in the first substrate;

fusion bonding a wafer on the first substrate; and

etching the wafer to form the movable element.

9. A semiconductor device comprising:

a bonding structure over a first substrate;

a support structure over the first substrate, wherein the support structure protrudes laterally from the bonding structure; and

a second substrate over the bonding structure and the support structure.

10. The semiconductor device of claim 9, wherein the bonding structure and the support structure comprise a same material.

11. The semiconductor device of claim 9 further comprising a TSV extending through a backside of the second substrate, wherein the overlying TSV is aligned with the bonding structure and the support structure.

12. The semiconductor device of claim 11, wherein the support structure surrounds a projection of the overlying TSV by a width from about 1 um to about 20 um.

13. The semiconductor device of claim 9 further comprising:

a first dielectric layer on the first substrate;

a first recess in the first dielectric layer; and

a MEMS structure over the first dielectric layer and the first recess, wherein the MEMS structure comprises a movable element and an adjacent static element, and wherein the bonding structure and the support structure are on the static element.

14. The semiconductor device of claim 13 further comprising:

an interconnect structure on a frontside of the second substrate;

a second dielectric layer between the interconnect structure and the MEMS structure;

a second recess in the second dielectric layer; and

a TSV extending through a backside of the second substrate, wherein the overlying TSV is aligned with the bonding structure and the support structure, and wherein the TSV is coupled to the interconnect structure.

15. The semiconductor device of claim 9, further comprising a plurality of TSVs on a backside of the second substrate, wherein the overlying TSVs are aligned with the bonding structure and the support structure.

16. The semiconductor device of claim 15, wherein the semiconductor device comprises four sides, and wherein each of the four sides comprises at least one of the plurality of TSVs.

17. A MEMS device comprising:

a MEMS structure over a first substrate, wherein the MEMS structure comprises a movable element and an adjacent static element;

a bonding structure over the static element;

a second substrate over the MEMS structure, wherein the first substrate, the bonding structure, and the second substrate form a cavity around the MEMS structure; and

a TSV extending through a backside of the second substrate, wherein the bonding structure is configured to support the overlying TSV.

18. The MEMS device of claim 17, wherein the cavity comprises a first recess in the first substrate and a second recess in the second substrate.

19. The MEMS device of claim 17, wherein the bonding structure completely surrounds a projection of the overlying TSV by a width from about 1 um to about 20 um.

20. The MEMS device of claim 17, wherein the overlying TSV may be circular in shape, and wherein the bonding structure conformally surrounds a projection of the overlying TSV.