Methods for chemical etching of silicon

Patent metadata

Field	Value
Publication number	US-10177002-B2
Application number	US-201715459536-A
Country	US
Kind code	B2
Filing date	Mar 15, 2017
Priority date	Apr 29, 2016
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

Improved methods for chemically etching silicon are provided herein. In some embodiments, a method of etching a silicon material includes: (a) exposing the silicon material to a halogen-containing gas; (b) evacuating the halogen-containing gas from the semiconductor processing chamber; (c) exposing the silicon material to an amine vapor to etch a monolayer of the silicon material; (d) evacuating the amine vapor from the semiconductor processing chamber and; (e) optionally repeating (a)-(d) to etch the silicon material to a predetermined thickness.

First claim

The invention claimed is:

1. A method of etching a silicon material on a substrate in a semiconductor processing chamber, comprising:
(a) exposing the silicon material to a halogen-containing gas in a non-plasma state for a first period of time;
(b) evacuating the halogen-containing gas from the semiconductor processing chamber;
(c) subsequently, exposing the silicon material to an amine vapor in a non-plasma state for a second period of time to etch a monolayer of the silicon material;
(d) evacuating the amine vapor from the semiconductor processing chamber; and
(e) optionally repeating (a)-(d) to etch the silicon material to a predetermined thickness.

2. The method of claim 1 , wherein the halogen-containing gas is at least of a chlorine-containing gas, a bromine-containing gas and/or a fluorine-containing gas.

3. The method of claim 1 , wherein the amine vapor is a primary amine, a secondary amine, a tertiary amine, or an aromatic amine.

4. The method of claim 1 , further comprising removing a native oxide layer from a surface of the silicon material prior to exposing the silicon material to the halogen-containing gas.

5. The method of claim 1 , wherein the first period of time is up to about 5 minutes.

6. The method of claim 1 , wherein a temperature of the substrate during exposure of the silicon material to the halogen-containing gas is about 25 degrees Celsius to about a decomposition temperature of the amine vapor.

7. The method of claim 1 , wherein a pressure of the semiconductor processing chamber during exposure of the silicon material to the halogen-containing gas is about 100 mtorr to about 10 torr.

8. The method of claim 1 , further comprising purging the semiconductor processing chamber with an inert gas after evacuating the halogen-containing gas from the semiconductor processing chamber.

9. The method of claim 1 , wherein the second period of time is about 10 ms to about 600 seconds.

10. The method of claim 1 , wherein a temperature of the substrate during exposure of the silicon material to the amine vapor is about 60 degrees Celsius to about a decomposition temperature of the amine vapor.

11. The method of claim 1 , wherein a pressure of the semiconductor processing chamber during exposure of the silicon material to the amine vapor is about 100 mtorr to about 10 torr.

12. The method of claim 1 , further comprising purging the semiconductor processing chamber with an inert gas after evacuating the amine vapor from the semiconductor processing chamber.

13. The method of claim 1 , further comprising a patterned silicon oxide material disposed atop the silicon material, wherein (a)-(e) selectively etches the silicon material over the patterned silicon oxide material.

14. A method of etching a silicon material on a substrate in a semiconductor processing chamber, comprising:
(a) removing a native oxide layer from a surface of the silicon material;
(b) exposing the silicon material to a chlorine-containing gas in a non-plasma state for a first period of time;
(c) evacuating the chlorine-containing gas from the semiconductor processing chamber;
(d) purging the semiconductor processing chamber with an inert gas after evacuating the chlorine-containing gas from the semiconductor processing chamber;
(e) subsequently, exposing the silicon material to a diethylamine vapor in a non-plasma state for a second period of time to etch a monolayer of the silicon material;
(f) evacuating the diethylamine vapor from the semiconductor processing chamber;
(g) purging the semiconductor processing chamber with an inert gas after evacuating the diethylamine vapor from the semiconductor processing chamber; and
(h) optionally repeating (b)-(g) to etch the silicon material to a predetermined thickness.

15. The method of claim 14 , wherein the first period of time is up to about 5 minutes.

16. The method of claim 14 , wherein a temperature of the substrate during exposure of the silicon material to the chlorine-containing gas is about 25 degrees Celsius to about a decomposition temperature of the diethylamine vapor.

17. The method of claim 14 , wherein the second period of time is about 10 msec to about 600 seconds.

18. The method of claim 14 , wherein a temperature of the substrate during exposure of the silicon material to the diethylamine vapor is about 60 degrees Celsius to about 150 degrees Celsius.

19. The method of claim 14 , further comprising a patterned silicon oxide material disposed atop the silicon material, wherein (b)-(h) selectively etches the silicon material over the patterned silicon oxide material.

20. A non-transitory computer readable medium having instructions stored thereon that, when executed, cause a method for etching a silicon material on a substrate in a semiconductor processing chamber, the method comprising:
(a) exposing the silicon material to a halogen-containing gas in a non-plasma state for a first period of time;
(b) evacuating the halogen-containing gas from the semiconductor processing chamber;
(c) subsequently, exposing the silicon material to an amine vapor in a non-plasma state for a second period of time to etch a monolayer of the silicon material;
(d) evacuating the amine vapor from the semiconductor processing chamber; and
(e) optionally repeating (a)-(d) to etch the silicon material to a predetermined thickness.

Assignees

• Applied Materials Inc

Inventors

• Bajaj Geetika
• Patil Ravindra
• Goradia Prerna
• Visser Robert Jan

Classifications

• H10P50/246

  of Group III-V materials · CPC title

• H10P72/0421

  for drying etching · CPC title

• H10P72/0402

  Apparatus for fluid treatment (H10P72/0441, H10P72/0448 take precedence) · CPC title

• H10P70/10

  Cleaning before device manufacture, i.e. Begin-Of-Line process · CPC title

• H10P50/283

  by chemical means · CPC title