Anti-stiction process for MEMS device

Patent metadata

Field	Value
Publication number	US-10513432-B2
Application number	US-201815904085-A
Country	US
Kind code	B2
Filing date	Feb 23, 2018
Priority date	Jul 31, 2017
Publication date	Dec 24, 2019
Grant date	Dec 24, 2019

Abstract

A method for treating a micro electro-mechanical system (MEMS) component is disclosed. In one example, the method includes the steps of providing a first wafer, treating the first wafer to form cavities and at least an oxide layer on a top surface of the first wafer using a first chemical vapor deposition (CVD) process, providing a second wafer, bonding the second wafer on a top surface of the at least one oxide layer, treating the second wafer to form a first plurality of structures, depositing a layer of Self-Assembling Monolayer (SAM) to a surface of the MEMS component using a second CVD process.

First claim

What is claimed is:

1. A method, the method comprising the steps of:
providing a first wafer;
treating the first wafer to form cavities and at least one oxide layer on a top surface of the first wafer using a first chemical vapor deposition process;
providing a second wafer;
bonding the second wafer on a top surface of the at least one oxide layer;
treating the second wafer to form a first plurality of structures, wherein treating the second wafer further comprises etching a layer of germanium over the second wafer to form a second plurality of structures; and
depositing a layer of Self-Assembling Monolayer (SAM) to a surface of a micro electro-mechanical system (MEMS) component using a second chemical vapor deposition process.

2. The method of claim 1 , wherein the step of treating the first wafer further comprises the step of:
etching the first wafer to create a first plurality of upward facing cavities.

3. The method of claim 2 , wherein the step of treating the first wafer further comprises the step of:
depositing an oxide layer on the top of the first wafer with the first plurality of the upward facing cavities using the first chemical vapor deposition process, wherein the first chemical vapor contains at least the oxide.

4. The method of claim 1 , wherein the step of treating the second wafer further comprises the step of:
fusing the second wafer on a top of the at least one oxide layer; and
etching the second wafer to form the second plurality of structures.

5. The method of claim 1 , wherein the step of treating the second wafer further comprises the step of:
depositing the layer of germanium over the second wafer using a physical vapor deposition process.

6. The method of claim 1 , wherein the step of treating the second wafer further comprises the step of:
etching the second wafer to form a plurality of MEMS actuators.

7. The method of claim 6 , further comprises the step of:
treating the MEMS component by maintaining a temperature at a constant value for a period of time to partially remove the layer of SAM on the layer of germanium.

8. The method of claim 7 , wherein the temperature is in a range of 430 to 490 degrees Celsius.

9. The method of claim 7 , wherein the period of time is in a range of 30 to 240 minutes.

10. The method of claim 7 , further comprises the step of:
wet etching the MEMS component to completely remove the layer of SAM on the layer of germanium.

11. The method of claim 10 , further comprises the step of:
bonding the MEMS component to a complementary metal-oxide-semiconductor (CMOS) wafer using eutectic bonding.

12. A process, the process comprising the steps of:
providing a micro electro-mechanical system (MEMS) component that comprises a layer of germanium;
depositing a layer of Self-Assembling Monolayer (SAM) to the MEMS component using a chemical vapor deposition process; and
maintaining a temperature of the MEMS component at a value for a period of time to partially remove the layer of SAM on the layer of germanium.

13. The process of claim 12 , further comprises the step of:
wet etching the MEMS component to completely remove the layer of SAM on the layer of germanium.

14. The process of claim 13 , further comprises the step of:
bonding the MEMS component to a CMOS wafer using eutectic bonding.

15. The process of claim 12 , wherein the temperature is in a range of 430 to 490 degrees Celsius.

16. The process of claim 12 , wherein the period of time is in a range of 30 to 240 minutes.

17. A method, comprising:
providing a micro electro-mechanical system (MEMS) component that comprises a layer of germanium;
depositing a layer of Self-Assembling Monolayer (SAM) to the MEMS component; and
wet etching the MEMS component to completely remove the layer of SAM on the layer of germanium.

18. The method of claim 17 , further comprising:
bonding the MEMS component to a CMOS wafer.

19. The method of claim 18 , wherein the MEMS component is bonded to the CMOS wafer based on a eutectic bonding.

20. The method of claim 17 , wherein the layer of SAM is deposited based on a chemical vapor deposition process.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Weng Jui-Chun
• Sanagavarapu Lavanya
• Hu Ching-Hsiang
• Wu Wei-Ding
• Cheng Shyh-Wei
• Chiang Ji-Hong
• Chen Hsin-Yu
• Hsu Hsi-Cheng

Classifications

• H10P14/3246

  Monolayers · CPC title

• H10P14/34

  Deposited materials, e.g. layers · CPC title

• B81C2203/0118

  Bonding a wafer on the substrate, i.e. where the cap consists of another wafer · CPC title

• B81C2201/112

  Depositing an anti-stiction or passivation coating, e.g. on the elastic or moving parts · CPC title

• B81C1/00357

  involving bonding one or several substrates on a non-temporary support, e.g. another substrate · CPC title