Gas-phase selective etching systems and methods

• US 10,573,527 B2
• Filed: 04/05/2019
• Issued: 02/25/2020
• Est. Priority Date: 04/06/2018
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Bajaj, Geetika, Visser, Robert Jan, Ingle, Nitin, Li, Zihui, Goradia, Prerna Sonthalia
• Primary Examiner(s): Culbert, Roberts P
• Application Number:
  US16/376,508
• Publication Number:
  US 20190311909A1
• Time in Patent Office: 326 Days
• Field of Search: None
• CPC Class Codes: C23F 1/12 Gaseous compositions
• CPC Class Codes: H01L 21/02244 of a metallic layer
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/32135 by vapour etching only
• CPC Class Codes: H01L 21/32136 using plasmas

Abstract

Systems and methods of etching a semiconductor substrate may include flowing an oxygen-containing precursor into a substrate processing region of a semiconductor processing chamber. The substrate processing region may house the semiconductor substrate, and the semiconductor substrate may include an exposed metal-containing material. The methods may include flowing ammonia into the substrate processing region at a temperature above about 200° C. The methods may further include removing an amount of the metal-containing material.

Claims

1. A method of etching a semiconductor substrate, the method comprising:

flowing an oxygen-containing precursor into a substrate processing region housing the semiconductor substrate, wherein the semiconductor substrate includes an exposed metal-containing material;

flowing ammonia into the substrate processing region at a temperature above about 200°

C.; and

removing an amount of the metal-containing material.

2. The method of etching a semiconductor substrate of claim 1, wherein the oxygen-containing precursor is configured to react with the metal-containing material to produce a modified metal-containing material.

3. The method of etching a semiconductor substrate of claim 2, wherein the nitrogen-containing precursor is configured to react with the modified metal-containing material to produce a volatile complex.

4. The method of etching a semiconductor substrate of claim 1, wherein the oxygen-containing precursor comprises one or both of water or ozone.

5. The method of etching a semiconductor substrate of claim 1, wherein the pressure within the substrate processing region is maintained above or about 10 Torr.

6. The method of etching a semiconductor substrate of claim 5, wherein the pressure within the substrate processing region is maintained above or about 100 Torr.

7. The method of etching a semiconductor substrate of claim 1, wherein the oxygen-containing precursor and the nitrogen-containing precursor are flowed sequentially into the substrate processing region.

8. The method of etching a semiconductor substrate of claim 7, further comprising holding for a first period of time subsequent flowing the oxygen-containing precursor and prior to flowing the nitrogen-containing precursor.

9. The method of etching a semiconductor substrate of claim 8, wherein the first period of time is between about 5 seconds and about 30 seconds.

10. The method of etching a semiconductor substrate of claim 7, further comprising holding for a second period of time subsequent flowing the nitrogen-containing precursor.

11. The method of etching a semiconductor substrate of claim 10, wherein the second period of time is between about 10 seconds and about 60 seconds.

12. The method of etching a semiconductor substrate of claim 1, wherein the oxygen-containing precursor and the nitrogen-containing precursor are halogen free, and wherein the method comprises a plasma-free process.

13. The method of etching a semiconductor substrate of claim 1, wherein the method is performed at a temperature of greater than or about 300°

C.

14. The method of etching a semiconductor substrate of claim 1, wherein the process is performed in a continuous operation, and wherein the process removes greater than or about 4 Å

/min.

15. The method of etching a semiconductor substrate of claim 1, wherein the metal-containing material comprises titanium nitride.

16. A method of etching a semiconductor substrate, the method comprising:

removing a native oxide from a metal-containing material exposed on the semiconductor substrate;

flowing ozone into a substrate processing region housing the semiconductor substrate;

holding for a first period of time greater than or about 1 second;

flowing a nitrogen-containing precursor into the substrate processing region;

holding for a second period of time greater than or about 1 second; and

removing an amount of the metal-containing material.

17. The method of etching a semiconductor substrate of claim 16, further comprising flowing additional nitrogen-containing precursor into the substrate processing region.

18. The method of etching a semiconductor substrate of claim 16, wherein the method removes at least about 4 Å

per minute during the method.

19. The method of etching a semiconductor substrate of claim 16, wherein the nitrogen-containing precursor is ammonia.

20. The method of etching a semiconductor substrate of claim 16, wherein the pressure is maintained at greater than or about 100 Torr during the method.