Nitrogen-containing compounds for etching semiconductor structures

Patent metadata

Field	Value
Publication number	US-10256109-B2
Application number	US-201715497393-A
Country	US
Kind code	B2
Filing date	Apr 26, 2017
Priority date	Aug 31, 2015
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

A method for etching silicon-containing films is disclosed. The method includes the steps of introducing a vapor of a nitrogen containing etching compound into a reaction chamber containing a silicon-containing film on a substrate, wherein the nitrogen containing etching compound is an organofluorine compound containing at least one C≡N or C═N functional group; introducing an inert gas into the reaction chamber; and activating a plasma to produce an activated nitrogen containing etching compound capable of etching the silicon-containing film from the substrate.

First claim

What is claimed is:

1. A method of depositing an etch-resistant polymer layer on a substrate, the method comprising:
introducing a vapor of an organofluorine compound into a reaction chamber containing a substrate, the organofluorine compound having a formula selected from the group consisting of N≡C—R 1 , wherein R 1 has the formula H a F b C c and a=1-11, b=1-11, and c=1-5; (N≡C—)—(R 2 )—(—C≡N), wherein R 2 has the formula H a F b C c with a=0-11, b=1-11, and c=1-5; and R 1 x [—C═N(R 2 z )] y , wherein x=1-2, y=1-2, z=0-1, x+z=1-3, and each R 1 and R 2 independently has the formula H a F b C c with a=0-11, b=0-11, and c=0-5; and
plasma activating the organofluorine compound to form the etch-resistant polymer layer on the substrate,
wherein the organofluorine compound having a purity ranging from approximately 95% to approximately 99.999% by volume and comprising between approximately 10 parts per trillion to approximately 5% by volume water vapor impurities.

2. The method of claim 1 , wherein the organofluorine compound has the formula: N≡C—R 1 , wherein R 1 has the formula H a F b C c and a=1-11, b=1-11, and c=1-5, or (N≡C—)—(R 2 )—(—C≡N), wherein R 2 is a functional group having the formula H a F b C c with a=0-11, b=1-11, and c=1-5.

3. The method of claim 1 , wherein the organfluorine compound is selected from the group consisting of 2,2,3,3-tetrafluoropropionitrile, 2,3,3,3-tetrafluoropropionitrile (C 3 HF 4 N), difluoroacetonitrile (C 2 HF 2 N), trifluoroacetonitrile (C 2 F 3 N); Nonafluoropentanitrile (C 5 F 9 N); Pentafluoroallyl cyanide (C 4 F 5 N); Hexafluoroacetone imine (C 3 HF 6 N); 4,4,4-Trifluorocrotono-nitrile, 3,3,3-Trifluoropropionitrile, fluoroacetonitrile, octafluorohexane-1,6-dinitrile, 1,1-bis(trifluoromethyl)-2,2-dicyanoethylene, N,1,1,1,3,3,3-heptafluoro-propanamine), and 1,1,1,6,6,6-Hexafluoro-3-azahex-3-ene).

4. The method of claim 1 , wherein the nitrogen-containing fluorocarbon molecule is 2,3,3,3-tetrafluoropropionitrile (C 3 HF 4 N).

5. The method of claim 1 , wherein the nitrogen-containing fluorocarbon molecule is difluoroacetonitrile (C 2 HF 2 N).

6. The method of claim 1 , wherein the etch-resistant polymer layer forms a N-containing polymer passivation layer on sidewalls of a pattern etch structure.

7. The method of claim 6 , wherein the pattern etch structure has an aspect ratio ranging from 1:1 to 50:1.

8. The method of claim 7 , wherein the pattern etch structure has an aspect ratio ranging from 10:1 to 200:1.

9. The method of claim 6 , wherein the protection layer prevents ions and radicals from etching the sidewalls.

10. The method of claim 6 , wherein the etch-resistant polymer layer results in a pattern etch structure having a vertical profile that is straight with no bowing.

11. The method of claim 1 , further comprising removing the etch-resistant polymer layer using dry or wet etch chemistries.

12. The method of claim 1 , further comprising introducing an inert gas into the reaction chamber.

13. The method of claim 12 , wherein the inert gas is selected from the group consisting of He, Ar, Xe, Kr, Ne, N 2 , and combinations thereof.

14. A method of depositing an N-containing polymer passivation layer on a substrate, the method comprising:
introducing a vapor of an organofluorine compound into a reaction chamber containing a substrate, the organofluorine compound having a formula selected from the group consisting of N≡C—R 1 , wherein R 1 has the formula H a F b C c and a=1-11, b=1-11, and c=1-5; (N≡C—)—(R 2 )—(—C≡N), wherein R 2 has the formula H a F b C c with a=0-11, b=1-11, and c=1-5; and R 1 x [—C═N(R 2 z )] y , wherein x=1-2, y=1-2, z=0-1, x+z=1-3, and each R 1 and R 2 independently has the formula H a F b C c with a=0-11, b=0-11, and c=0-5; and
producing fragments of the organofluorine compound by activating a plasma to form the N-containing polymer passivation layer on the substrate,
wherein the organofluorine compound having a purity ranging from approximately 95% to approximately 99.999% by volume and comprising between approximately 10 parts per trillion to approximately 5% by volume water vapor impurities.

15. The method of claim 14 , wherein the organfluorine compound is selected from the group consisting of 2,2,3,3-tetrafluoropropionitrile, 2,3,3,3-tetrafluoropropionitrile (C 3 HF 4 N), difluoroacetonitrile (C 2 HF 2 N), trifluoroacetonitrile (C 2 F 3 N); Nonafluoropentanitrile (C 5 F 9 N); Pentafluoroallyl cyanide (C 4 F 5 N); Hexafluoroacetone imine (C 3 HF 6 N); 4,4,4-Trifluorocrotono-nitrile, 3,3,3-Trifluoropropionitrile, fluoroacetonitrile, octafluorohexane-1,6-dinitrile, 1,1-bis(trifluoromethyl)-2,2-dicyanoethylene, N,1,1,1,3,3,3-heptafluoro-propanamine, and 1,1,1,6,6,6-Hexafluoro-3-azahex-3-ene.

16. The method of claim 14 , further comprising removing the etch-resistant polymer layer using dry or wet etch chemistries.

17. The method of claim 14 , further comprising introducing an inert gas into the reaction chamber.

18. The method of claim 17 , wherein the inert gas is selected from the group consisting of He, Ar, Xe, Kr, Ne, N 2 , and combinations thereof.

19. The method of claim 1 , wherein the organofluorine compound has the formula: R 1 x [—C═N(R 2 z )] y , wherein x=1-2, y=1-2, z=0-1, x+z=1-3, and each R 1 and R 2 independently has the formula H a F b C c with a=0-11, b=0-11, and c=0-5.

Assignees

• Air Liquide American

Inventors

• Surla Vijay
• Gupta Rahul
• Pallem Venkateswara R

Classifications

• H10P50/287

  by chemical means · CPC title

• H10P76/20

  of masks comprising organic materials · CPC title

• H10P50/286

  of organic materials · CPC title

• H10P50/283 Primary

  by chemical means · CPC title

• H10P14/6336 Primary

  in the presence of a plasma [PECVD] · CPC title