MEMS Devices and Fabrication Methods Thereof

• US 20130334620A1
• Filed: 10/12/2012
• Published: 12/19/2013
• Est. Priority Date: 06/15/2012
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Chu, Chia-Hua, Cheng, Chun-Wen, Lin, Chung-Hsien, Lee, Te-Hao
• Granted Patent: US 9,452,924 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2203/0307 Anchors
• CPC Class Codes: B81B 2203/04 Electrodes
• CPC Class Codes: B81B 2207/07 Interconnects
• CPC Class Codes: B81B 3/0054 For holding or placing an element in a given position
• CPC Class Codes: B81C 1/00238 Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure

Abstract

A method for fabricating a MEMS device includes providing a micro-electro-mechanical system (MEMS) substrate having a sacrificial layer on a first side, providing a carrier including a plurality of cavities, bonding the first side of the MEMS substrate on the carrier, forming a first bonding material layer on a second side of the MEMS substrate, applying a sacrificial layer removal process to the MEMS substrate, providing a semiconductor substrate including a second bonding material layer and bonding the semiconductor substrate on the second side of the MEMS substrate.

Claims

1. A semiconductor device comprising:

a carrier having a plurality of cavities;

a micro-electro-mechanical system (MEMS) substrate bonded on the carrier, where the MEMS substrate comprises;

a first side bonded on the carrier;

a moving element located between a top electrode and a bottom electrode; and

a second side having a plurality of bonding pads; and

a semiconductor substrate bonded on the MEMS substrate.

2. The semiconductor device of claim 1, wherein:

the MEMS substrate comprises a plurality of air channels coupled to the cavities of the carrier.

3. The semiconductor device of claim 1, wherein:

each cavity of the plurality of cavities comprises an extrusion.

4. The semiconductor device of claim 1, further comprising:

a first dielectric layer deposited on the first side of the MEMS substrate;

a vapor HF stop layer formed over the dielectric layer;

a second dielectric layer formed over the vapor HF stop layer; and

a bonding layer formed over the second dielectric layer.

5. The semiconductor device of claim 4, where:

the first dielectric layer is a first oxide layer;

the vapor HF stop layer is a low stress nitride layer;

the second dielectric layer is a second oxide layer; and

the bonding layer is formed of polysilicon.

6. The semiconductor device of claim 1, further comprising:

a CMOS bonding layer on the semiconductor substrate, wherein the CMOS bonding layer is conductive.

7. The semiconductor device of claim 1, further comprising:

a conductive layer formed between the semiconductor substrate and the MEMS substrate, wherein the conductive layer is thinner than the MEMS substrate.

8. The semiconductor device of claim 1, wherein:

a first side of a cavity of the carrier is sealed by a first sealing layer; and

a second side of the cavity of the carrier is sealed by a second sealing layer, wherein the second side of the cavity is a nonbonding side of the carrier.

9. The semiconductor device of claim 8, wherein:

the first sealing layer is a first oxide layer; and

the second sealing layer is a second oxide layer.

10. The semiconductor device of claim 8, wherein:

the first sealing layer is a first oxide layer; and

the second sealing layer comprising;

a second oxide layer; and

an aluminum layer formed over the second oxide layer.

11. The semiconductor device of claim 8, further comprising:

an electrical readout structure formed over the second side of the cavity of the carrier.

12. A method comprising:

providing a micro-electro-mechanical system (MEMS) substrate having;

a sacrificial layer on a first side;

providing a carrier including a plurality of cavities;

bonding the first side of the MEMS substrate on the carrier;

forming a first bonding material layer on a second side of the MEMS substrate;

applying a sacrificial layer removal process to the MEMS substrate;

providing a semiconductor substrate including a second bonding material layer; and

bonding the semiconductor substrate on the second side of the MEMS substrate.

13. The method of claim 12, further comprising:

depositing a first dielectric layer on the first side of the MEMS substrate;

depositing a vapor HF stop layer on the first dielectric layer;

depositing a second dielectric layer on the vapor HF stop layer; and

forming a bonding layer on the second dielectric layer.

14. The method of claim 12, further comprising:

depositing a third dielectric layer on the carrier;

forming a plurality of openings in the carrier through an etching process;

forming a dielectric protection layer on sidewalls of the openings; and

enlarging the openings through an isotropic etching process.

15. The method of claim 12, further comprising:

forming a plurality of MEMS openings in the MEMS substrate from the second side of the MEMS substrate;

depositing a third dielectric layer to fill the MEMS openings;

forming a thin conductive layer on the third dielectric layer;

forming the first bonding material layer on the thin conductive layer; and

patterning the thin conductive layer to form a plurality of conductive elements and movable elements.

16. The method of claim 12, further comprising:

sealing a first side of a cavity of the carrier with a first sealing layer;

applying a thinning process to a second side of carrier until a second side of the cavity is exposed, wherein the second side of the carrier is a nonbonding side of the carrier; and

sealing the second side of the cavity with a second sealing layer.

17. The method of claim 16, further comprising:

forming an electrical readout structure over the second side of the carrier.

18. A method comprising:

providing a micro-electro-mechanical system (MEMS) device including;

forming a first sacrificial dielectric layer having a plurality of sealed trenches on a first side of the MEMS substrate;

forming a plurality of electrodes and mechanical bumps on the first sacrificial dielectric layer;

depositing a vapor HF stop layer on the first sacrificial dielectric layer;

depositing a second sacrificial dielectric layer on the vapor HF stop layer; and

forming a bonding layer on the second sacrificial dielectric layer;

providing a carrier including a plurality of cavities;

bonding the first side of the MEMS substrate on the carrier;

forming a first bonding material layer on a second side of the MEMS substrate;

applying a sacrificial layer removal process to the MEMS substrate;

providing a semiconductor substrate including a second bonding material layer; and

bonding the semiconductor substrate on the second side of the MEMS substrate.

19. The method of claim 18, further comprising:

depositing an oxide material on the first side of the MEMS substrate;

patterning the oxide material to form a plurality of trenches; and

depositing the oxide material on the trenches to form the sealed trenches.

20. The method of claim 18, further comprising:

forming a plurality of MEMS openings in the MEMS substrate from the second side of the MEMS substrate;

depositing a third dielectric layer to fill the MEMS openings;

forming a thin conductive layer on the third dielectric layer;

forming the first bonding material layer on the thin conductive layer; and

patterning the thin conductive layer to form a plurality of conductive bumps and mechanical structures.