Self-limiting atomic thermal etching systems and methods

• US 10,043,684 B1
• Filed: 02/06/2017
• Issued: 08/07/2018
• Est. Priority Date: 02/06/2017
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Arnepalli, Ranga Rao, Goradia, Prerna Sonthalia, Visser, Robert Jan, Ingle, Nitin, Korolik, Mikhail, Biswas, Jayeeta, Lodha, Saurabh
• Primary Examiner(s): Culbert, Roberts
• Application Number:
  US15/425,231
• Publication Number:
  US 20180226278A1
• Time in Patent Office: 547 Days
• Field of Search: 438705
• CPC Class Codes: C23F 1/12 Gaseous compositions
• CPC Class Codes: H01L 21/02244 of a metallic layer
• CPC Class Codes: H01L 21/31122 of layers not containing Si, e.g. PZT, Al2O3
• CPC Class Codes: H01L 21/32135 by vapour etching only
• CPC Class Codes: H01L 21/67742 Mechanical parts of transfer devices robots in general in B25J
• CPC Class Codes: H01L 21/67766 Mechanical parts of transfer devices robots in general in B25J

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 a nitrogen-containing precursor into the substrate processing region. 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, wherein the oxygen-containing precursor comprises water, ozone, or radical oxygen;

flowing a nitrogen-containing precursor into the substrate processing region; 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 nitrogen-containing precursor comprises an amine.

5. The method of etching a semiconductor substrate of claim 4, wherein the amine comprises diethylamine, propylamine, or N-ethylmethylamine.

6. 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.

7. The method of etching a semiconductor substrate of claim 6, further comprising holding for a first period of time subsequent flowing the oxygen-containing precursor and prior to flowing the nitrogen-containing precursor.

8. The method of etching a semiconductor substrate of claim 7, wherein the first period of time is between about 5 seconds and about 30 seconds.

9. The method of etching a semiconductor substrate of claim 6, further comprising holding for a second period of time subsequent flowing the nitrogen-containing precursor.

10. The method of etching a semiconductor substrate of claim 9, wherein the second period of time is between about 10 seconds and about 60 seconds.

11. The method of etching a semiconductor substrate of claim 1, wherein the oxygen-containing precursor comprises water or ozone and the nitrogen-containing precursor is halogen free, and wherein the method comprises a plasma-free process.

12. The method of etching a semiconductor substrate of claim 1, wherein the method is performed at a temperature of between about 100°

C. and about 225°

C.

13. The method of etching a semiconductor substrate of claim 1, wherein flowing the oxygen-containing precursor and flowing the nitrogen-containing precursor are repeated in at least one additional cycle.

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

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

forming plasma effluents of an oxygen-containing precursor in a remote plasma region of a semiconductor processing chamber;

flowing the plasma effluents into a substrate processing region housing the semiconductor substrate, wherein the semiconductor substrate includes an exposed metal-containing material, wherein the substrate processing region is fluidly coupled with the remote plasma region, and wherein the oxygen-containing precursor is configured to react with the metal-containing material to produce a modified metal-containing material;

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

flowing a nitrogen-containing precursor into the substrate processing region, wherein the nitrogen-containing precursor is configured to react with the modified metal-containing material to produce a volatile complex;

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

removing an amount of the metal-containing material.

16. The method of etching a semiconductor substrate of claim 15, further comprising flowing additional nitrogen-containing precursor into the substrate processing region.

17. The method of etching a semiconductor substrate of claim 15, wherein the method removes at least about 0.2 Å

per cycle of flowing the plasma effluents and flowing the nitrogen-containing precursor into the substrate processing region.

18. The method of etching a semiconductor substrate of claim 15, wherein the nitrogen-containing precursor is selected from the group of precursors consisting of a water-methylamine solution, a water-ethylamine solution, diethylamine, propylamine, dipropylamine, a water-diethylamine solution, and N-ethylmethylamine.

19. The method of etching a semiconductor substrate of claim 15, wherein the plasma effluents are produced at a plasma power below or about 500 W.

20. 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 a nitrogen-containing precursor into the substrate processing region; and

removing an amount of the metal-containing material, wherein the oxygen-containing precursor and the nitrogen-containing precursor are halogen free, and wherein the method comprises a plasma-free process.