Method of stiction prevention by patterned anti-stiction layer

Patent metadata

Field	Value
Publication number	US-10654707-B2
Application number	US-201816199461-A
Country	US
Kind code	B2
Filing date	Nov 26, 2018
Priority date	Jun 30, 2017
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

The present disclosure, in some embodiments, relates to a method for manufacturing a MEMS apparatus. The method may be performed by forming an anti-stiction layer on one or more respective surfaces of a handle substrate and a MEMS substrate. The anti-stiction layer is patterned, therein defining a patterned anti-stiction layer that uncovers one or more predetermined locations associated with a bonding of the handle substrate to the MEMS substrate. The handle substrate is bonded to the MEMS substrate at the one or more predetermined locations.

First claim

What is claimed is:

1. A method for manufacturing a microelectromechanical systems (MEMS) apparatus, the method comprising:
forming a dielectric layer and a bump feature directly above a conductive routing layer, the bump feature laterally separated from the dielectric layer;
forming an anti-stiction layer on the dielectric layer and the bump feature;
patterning the anti-stiction layer to remove the anti-stiction layer from over a part of the conductive routing layer and therein defining a patterned anti-stiction layer that uncovers one or more predetermined locations associated with a bonding of a handle substrate to a MEMS substrate;
increasing a roughness of an upper surface of the patterned anti-stiction layer; and
bonding the handle substrate to the MEMS substrate at the one or more predetermined locations.

2. The method of claim 1 , wherein forming the anti-stiction layer comprises depositing an organic material on the handle substrate.

3. The method of claim 2 , wherein patterning the anti-stiction layer comprises physically removing the organic material from the one or more predetermined locations.

4. The method of claim 1 , wherein increasing the roughness of the upper surface of the patterned anti-stiction layer comprises exposing the upper surface of the anti-stiction layer to a chemical or physical treatment.

5. The method of claim 2 , wherein patterning the anti-stiction layer comprises one or more of a physical etch and a chemical etch of the one or more predetermined locations.

6. The method of claim 1 , wherein increasing the roughness of the upper surface of the patterned anti-stiction layer comprises roughening a substantially flat upper surface of the patterned anti-stiction layer at one or more stiction locations.

7. The method of claim 1 , wherein patterning the anti-stiction layer comprises plasma etching a surface of the handle substrate associated with the one or more predetermined locations.

8. The method of claim 1 , further comprising forming a conductive layer over the handle substrate prior to forming the anti-stiction layer, wherein the conductive layer is positioned between the handle substrate and the MEMS substrate at one or more stiction locations.

9. The method of claim 8 , wherein forming the conductive layer further comprises patterning the conductive layer in one or more regions associated with the one or more stiction locations, wherein the conductive layer contacts a metal layer.

10. A method for manufacturing a microelectromechanical systems (MEMS) apparatus, the method comprising:
forming a dielectric layer and a bump feature above a conductive routing layer that is over a substrate to define a handle substrate, the bump feature laterally separated from the dielectric layer;
forming an organic material on one or more surfaces of a MEMS substrate, therein defining an anti-stiction layer on the one or more surfaces of the MEMS substrate;
patterning the anti-stiction layer, therein defining a patterned anti-stiction layer that removes the anti-stiction layer at one or more predetermined locations associated with a bonding of the handle substrate to the MEMS substrate, wherein a portion of the anti-stiction layer remains on the one or more surfaces of the MEMS substrate after patterning; and
bonding the handle substrate to the MEMS substrate at the one or more predetermined locations such that the portion of the anti-stiction layer is directly over the bump feature.

11. The method of claim 10 , wherein the anti-stiction layer is formed onto a first sidewall, a second sidewall, and an upper surface of the bump feature; and
wherein patterning the anti-stiction layer removes the anti-stiction layer from the first sidewall of the bump feature, while leaving the patterned anti-stiction layer on the upper surface and the second sidewall of the bump feature.

12. A method for manufacturing a microelectromechanical systems (MEMS) apparatus, the method comprising:
forming a dielectric layer and a bump feature above a conductive routing layer that is over a substrate to define a handle substrate, the bump feature laterally separated from the dielectric layer;
forming a separate conductive layer over the bump feature and over the conductive routing layer;
forming an anti-stiction layer on the handle substrate and directly over the bump feature and the separate conductive layer;
defining a patterned anti-stiction layer by removing the anti-stiction layer from an upper surface of the dielectric layer, wherein the anti-stiction layer remains over the bump feature and the separate conductive layer after patterning; and
bonding the upper surface of the dielectric layer to a bonding region of a MEMS substrate.

13. The method of claim 10 ,
wherein the anti-stiction layer is formed onto sidewalls and an upper surface of the bump feature; and
wherein patterning the anti-stiction layer removes the anti-stiction layer from the sidewalls of the bump feature, while leaving the patterned anti-stiction layer on the upper surface of the bump feature.

14. The method of claim 10 ,
wherein the anti-stiction layer is formed onto sidewalls and an upper surface of the bump feature; and
wherein the anti-stiction layer remains on the upper surface and the sidewalls of the bump feature after patterning.

15. The method of claim 12 , wherein the anti-stiction layer is formed onto the MEMS substrate prior to bonding the upper surface of the dielectric layer to the bonding region of the MEMS substrate.

16. The method of claim 12 , wherein a plane extending along the upper surface of the dielectric layer is above an uppermost surface of the bump feature.

17. The method of claim 12 , wherein bonding the upper surface of the dielectric layer to the bonding region of the MEMS substrate comprises bringing the upper surface of the dielectric layer into direct contact with the bonding region of the MEMS substrate.

18. The method of claim 12 ,
wherein the anti-stiction layer is formed onto opposing sidewalls and an upper surface of the bump feature; and
wherein patterning the anti-stiction layer removes the anti-stiction layer from the opposing sidewalls of the bump feature.

19. The method of claim 12 , wherein removing the anti-stiction layer removes the anti-stiction layer from a first upper surface of the separate conductive layer, while leaving the patterned anti-stiction layer on a second upper surface of the separate conductive layer.

20. The method of claim 12 , wherein removing the anti-stiction layer removes the anti-stiction layer from an upper surface of the conductive routing layer, while leaving the patterned anti-stiction layer on a first upper surface and a second upper surface of the separate conductive layer and laterally extending past opposing outermost sidewalls of the separate conductive layer.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Chang Kuei-Sung
• Lai Fei-Lung
• Tsai Shang-Ying
• Hsieh Cheng Yu

Classifications

• B81B2201/0242

  Gyroscopes · CPC title

• B81C2201/115

  Roughening a surface · CPC title

• B81B2201/0235

  Accelerometers · CPC title

• B81C2201/112

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

• B81B3/001 Primary

  Structures having a reduced contact area, e.g. with bumps or with a textured surface · CPC title