Etching substrates using ALE and selective deposition

• US 10,685,836 B2
• Filed: 03/21/2019
• Issued: 06/16/2020
• Est. Priority Date: 04/29/2016
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Tan, Samantha, Yu, Jengyi, Wise, Richard, Shamma, Nader, Pan, Yang
• Primary Examiner(s): Ahmed, Shamim
• Application Number:
  US16/361,083
• Publication Number:
  US 20190244805A1
• Time in Patent Office: 453 Days
• Field of Search: None
• CPC Class Codes: G03F 7/427 using plasma means only
• CPC Class Codes: H01J 2237/334 Etching
• CPC Class Codes: H01J 37/32183 Matching circuits
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32899 Multiple chambers, e.g. cluster tools
• CPC Class Codes: H01L 21/02115 the material being carbon, e.g. alpha-C, diamond or hydrogen doped carbon
• CPC Class Codes: H01L 21/0273 characterised by the treatment of photoresist layers
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/3086 characterised by the process involved to create the mask, e.g. lift-off masks, sidewalls, or to modify the mask, e.g. pre-treatment, post-treatment
• CPC Class Codes: H01L 21/31056 the removal being a selective chemical etching step, e.g. selective dry etching through a mask
• CPC Class Codes: H01L 21/31058 of organic layers
• CPC Class Codes: H01L 21/31122 of layers not containing Si, e.g. PZT, Al2O3
• CPC Class Codes: H01L 21/31138 by dry-etching

Abstract

Methods of and apparatuses for processing substrates having carbon-containing material using atomic layer etch and selective deposition are provided. Methods involve exposing a carbon-containing material on a substrate to an oxidant and igniting a first plasma to modify a surface of the substrate and exposing the modified surface to a second plasma at a bias power to remove the modified surface. Methods also involve selectively depositing a second carbon-containing material onto the substrate using a precursor having a chemical formula of C_xH_y, where x and y are integers greater than or equal to 1. ALE and selective deposition may be performed without breaking vacuum.

Claims

1. A method of processing substrates, the method comprising:

(a) exposing a substrate comprising a first carbon-containing material to an oxidant and igniting a first plasma to modify a surface of the first carbon-containing material; and

(b) exposing the modified surface to a second plasma at a bias power and for a duration sufficient to remove the modified surface without sputtering.

2. The method of claim 1, further comprising (c) selectively depositing a second carbon-containing material on the substrate to fill crevices on the first carbon-containing material.

3. The method of claim 2, wherein selectively depositing the second carbon-containing material on the substrate comprises applying a self bias at a power between about 5V and about 15V and igniting a plasma using a plasma power between about 30 W and about 500 W.

4. The method of claim 3, wherein selectively depositing the second carbon-containing material on the substrate further comprises introducing methane.

5. The method of claim 4, wherein selectively depositing the second carbon-containing material on the substrate further comprises introducing a diluent selected from the group consisting of nitrogen, helium, argon, hydrogen, and combinations thereof.

6. The method of claim 2, wherein (c) comprises exposing the substrate to methane to adsorb a layer of methane to the surface of the first carbon-containing material and exposing the substrate to a third plasma.

7. The method of claim 1, wherein the bias power may be between about 30V and about 100V.

8. The method of claim 1, wherein the oxidant is a strong oxidant.

9. The method of claim 8, wherein the strong oxidant is oxygen.

10. The method of claim 8, wherein the first plasma is generated using a plasma power between about 15 W and about 500 W.

11. The method of claim 8, wherein the first plasma is ignited with another bias power between about 5V and 50V.

12. The method of claim 1, wherein the oxidant is a weak oxidant.

13. The method of claim 12, wherein the weak oxidant is selected from the group consisting of carbon dioxide, carbon monoxide, sulfur dioxide, nitric oxide, nitrogen, and ammonia.

14. The method of claim 12, wherein the first plasma is generated using a plasma power between about 30 W and about 500 W.

15. The method of claim 12, wherein the first plasma is ignited with another bias power between about 30V and about 100V.

16. The method of claim 1, wherein the first carbon-containing material is selected from the group consisting of photoresist, amorphous carbon, and graphene.

17. The method of claim 1, wherein the first carbon-containing material is a photoresist patterned by extreme ultraviolet lithography.

18. The method of claim 1, wherein the second plasma in (b) is generated by introducing an inert gas selected from the group consisting of hydrogen, helium, nitrogen, argon, and neon and igniting the second plasma.

19. A method of processing substrates, the method comprising:

(a) exposing a substrate comprising a first carbon-containing material to an oxidant and igniting a first plasma to modify a surface of the first carbon-containing material;

(b) exposing the modified surface to a second plasma at a bias power and for a duration sufficient to remove the modified surface without sputtering; and

(c) selectively depositing a second carbon-containing material on the substrate to fill crevices on the first carbon-containing material using a precursor having a chemical formula of C_xH_y, where x and y are integers greater than or equal to 1.

20. The method of claim 19, wherein the precursor comprises methane.