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

Patent metadata

Field	Value
Publication number	US-2016233102-A1
Application number	US-201615134144-A
Country	US
Kind code	A1
Filing date	Apr 20, 2016
Priority date	Dec 21, 2007
Publication date	Aug 11, 2016
Grant date	—

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 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 , wherein the oxygen containing gas comprises SO 2 and O 2 , the method 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.

14 . An apparatus for etching features into a silicon layer, comprising:
a plasma processing chamber, comprising:
a vacuum chamber;
a dielectric window forming a side of the vacuum chamber;
at least one antenna adjacent to the dielectric window for providing power for sustaining a plasma;
at least one plasma power source electrically connected to the at least one antenna;
a substrate support for supporting a silicon substrate within the plasma processing chamber;
a pressure regulator for regulating the pressure in the plasma processing chamber;
a gas inlet for providing gas into the plasma processing chamber; and
a gas outlet for exhausting gas from the plasma processing chamber;
a gas source in fluid connection with the gas inlet, comprising:
an oxygen containing gas source;
a fluorine containing gas source; and
an optional additive gas source; and
a controller controllably connected to the gas source and the at least one antenna, comprising:
at least one processor; and
computer readable media, comprising:
computer readable code for providing an etch gas from the gas source to the plasma processing chamber, the etch gas comprising an oxygen containing gas and a fluorine containing gas;
computer readable code for generating a plasma from the etch gas;
computer readable code for providing a bias voltage;
computer readable code for etching features into the silicon layer using the plasma; and
computer readable code for stopping the etch gas flowing from the gas source to the plasma processing chamber.

15 . The apparatus as recited in claim 14 , wherein the oxygen containing gas source comprises a SO 2 gas source and an O 2 gas source, the computer readable media further comprising:
computer readable code for 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.

16 . The apparatus as recited in claim 15 , the computer readable media further comprising:
computer readable code for ramping down a flow of SO 2 during the etching.

17 . The apparatus as recited in claim 14 , wherein the oxygen containing gas source comprises a SO 2 gas source, and the fluorine containing gas source comprises a SF 6 gas source, and the additive gas source comprises a SiF 4 gas source.

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