DIRECTIONAL SIO2 ETCH USING PLASMA PRE-TREATMENT AND HIGH-TEMPERATURE ETCHANT DEPOSITION

• US 20140193979A1
• Filed: 09/19/2013
• Published: 07/10/2014
• Est. Priority Date: 10/02/2012
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: OR, David T., COLLINS, Joshua, CHANG, Mei
• Granted Patent: US 9,177,780 B2
• Time in Patent Office: Days
• US Class Current: 438/714
• CPC Class Codes: H01L 21/02 Manufacture or treatment of semiconductor devices or of parts thereof
• CPC Class Codes: H01L 21/02057 Cleaning during device manufacture

Abstract

Methods for processing a substrate are described herein. Methods can include positioning a substrate with an exposed surface comprising a silicon oxide layer in a processing chamber, biasing the substrate, treating the substrate to roughen a portion of the silicon oxide layer, heating the substrate to a first temperature, exposing the exposed surface of the substrate to a plasma comprising ammonium fluoride to form one or more volatile products while maintaining the first temperature, and heating the substrate to a second temperature, which is higher than the first temperature, to sublimate the volatile products.

Claims

1. A method, comprising:

positioning a substrate with an exposed surface comprising a silicon oxide layer in a processing chamber;

biasing the substrate;

treating the substrate to roughen a portion of the silicon oxide layer;

heating the substrate to a first temperature;

exposing the exposed surface of the substrate to a plasma comprising ammonium fluoride (NH₄F) to form one or more volatile products; and

heating the substrate to a second temperature, which is higher than the first temperature, to sublimate the volatile products.

2. The method of claim 1, wherein the substrate has one or more vias or trenches formed on the exposed surface.

3. The method of claim 1, wherein the first temperature is a temperature of at least 65°

C.

4. The method of claim 1, wherein the first temperature is a temperature of between 70°

C. and 90°

C.

5. The method of claim 1, wherein the second temperature is a temperature of greater than 100°

C.

6. The method of claim 1, wherein heating the substrate to a second temperature further comprises exposing the exposed surface of the substrate a low energy inert plasma.

7. The method of claim 1, wherein the plasma comprising ammonium fluoride is formed remotely.

8. The method of claim 1, wherein the plasma comprising ammonium fluoride is formed from a gas mixture comprising ammonia (NH₃) and nitrogen trifluoride (NF₃).

9. The method of claim 8, wherein the gas mixture is a 1:

1 ratio of ammonia (NH₃) and nitrogen trifluoride (NF₃) respectively.

10. The method of claim 1, wherein the substrate is roughened by a low energy inert plasma.

11. A method, comprising:

positioning a silicon-containing substrate in a processing chamber, the silicon-containing substrate comprising;

an exposed surface;

one or more microstructures formed in the exposed surface; and

a native oxide layer formed on the exposed surface;

biasing the substrate;

exposing the substrate to a low energy inert plasma to form amorphous silicon oxide on surface perpendicular to the flow of the low energy inert plasma;

heating the substrate to a first temperature;

exposing the surface of the substrate to a plasma comprising ammonium fluoride (NH₄F) to form one or more volatile products; and

heating the substrate to a second temperature, which is higher than the first temperature, to sublimate the volatile products.

12. The method of claim 11, wherein the first temperature and the second temperature are within 10°

C. of one another.

13. The method of claim 11, wherein the first temperature is a temperature of at least 65°

C.

14. The method of claim 11, wherein the first temperature is a temperature of between 70°

C. and 90°

C.

15. The method of claim 11, wherein the second temperature is a temperature of greater than 100°

C.

16. The method of claim 11, wherein heating the substrate to a second temperature further comprises exposing the exposed surface of the substrate a low energy inert plasma.

17. The method of claim 11, wherein the plasma comprising ammonium fluoride is formed remotely.

18. The method of claim 11, wherein the plasma comprising ammonium fluoride is formed from a gas mixture comprising ammonia (NH₃) and nitrogen trifluoride (NF₃).

19. The method of claim 18, wherein the gas mixture is a 1:

1 ratio of ammonia (NH₃) and nitrogen trifluoride (NF₃) respectively.

20. The method of claim 11, wherein the plasma comprising ammonium fluoride is a non-sputtering plasma.