Fabrication of a silicon structure and deep silicon etch with profile control

Patent metadata

Field	Value
Publication number	US-9865472-B2
Application number	US-201615134144-A
Country	US
Kind code	B2
Filing date	Apr 20, 2016
Priority date	Dec 21, 2007
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

A method of etching features into a silicon layer with a steady-state gas flow is provided. An etch gas comprising an oxygen containing gas and a fluorine containing gas is provided. A plasma is provided from the etch gas. Then, the flow of the etch gas is stopped.

First claim

What is claimed is:

1. A method of etching features into a silicon layer with a steady-state gas flow, the method comprising:
providing an etch gas comprising:
an oxygen containing gas comprising SO 2 and O 2 ; and
a fluorine containing gas;

generating a plasma from the etch gas;
providing a bias voltage;
etching features into the silicon layer using the plasma; and
stopping the etch gas.

2. The method as recited in claim 1 , further comprising:
controlling at least one of a total flow or a ratio of SO 2 to O 2 so as to control taper of the features.

3. The method as recited in claim 2 , further comprising:
ramping down a flow of SO 2 during said etching.

4. The method as recited in claim 1 , wherein the bias voltage is equal to or greater than 5 volt.

5. The method as recited in claim 1 , wherein the oxygen containing gas comprises at least one of SO 2 , CO 2 , CO, NO 2 , or N 2 O.

6. The method as recited in claim 5 , wherein the oxygen containing gas further comprises O 2 .

7. The method as recited in claim 1 , wherein the fluorine containing gas contains SF 6 or NF 3 .

8. The method as recited in claim 7 , wherein the etch gas further contains SiF 4 .

9. The method as recited in claim 1 , wherein the etch gas further contains HBr.

10. The method as recited in claim 1 , wherein the etch gas further comprises C 4 F 8 .

11. The method as recited in claim 1 , wherein the etch gas further comprises a boron containing gas.

12. The method as recited in claim 1 , wherein in said etching, an aspect ratio of the features is at least 80.

13. The method as recited in claim 1 , wherein in said etching, a depth of the features is at least 80 μm.

Assignees

• Lam Res Corp

Inventors

• Chebi Robert
• Lin Frank
• Winniczek Jaroslaw W
• Chen Wan-Lin
• Moore Erin
• Zheng Lily
• Lassig Stephan
• Bogart Jeff
• Rusu Camelia

Classifications

• H10P70/20

  Cleaning during device manufacture · CPC title

• H10P50/287

  by chemical means · CPC title

• H10P50/283

  by chemical means · CPC title

• H10P50/268

  of silicon-containing layers · CPC title

• H10P50/267

  using plasmas · CPC title