Formation of SiOCN thin films

1. A method of forming a silicon oxycarbonitride (SiOCN) thin film on a substrate in a reaction space by a plasma enhanced atomic layer deposition (PEALD) process, wherein the PEALD process comprises at least one deposition cycle comprising:

contacting a surface of the substrate with a vapor phase silicon precursor to thereby adsorb a silicon species on the surface of the substrate;

contacting the adsorbed silicon species with at least one reactive species generated by plasma formed from gas that does not comprise oxygen;

optionally repeating the contacting steps until a SiOCN film of a desired thickness has been formed; and

a hydrogen plasma treatment cycle carried out after a predetermined number of deposition cycles, the hydrogen plasma treatment cycle comprising contacting the substrate with a reactive species generated by a plasma from hydrogen;

wherein the silicon precursor is selected from the group consisting of the following general formulas:

(R I O) 4-x Si(R II —NH 2 ) x   (1)

wherein x is an integer from 1 to 4;

R I is independently selected from the group consisting of alkyl groups; and

R II is independently selected from the group consisting of hydrocarbon groups;

(R I O) 3 Si—R II —NH 2   (2)

wherein R I is independently selected from the group consisting of alkyl groups; and

R II is independently selected from the group consisting of hydrocarbon groups;

(R I O) 4-x Si(—[CH 2 ] n —NH 2 ) x   (3)

wherein x is an integer from 1 to 4;

n is an integer from 1-5; and

R I is independently selected from the group consisting of alkyl groups.

2. The method of claim 1 , wherein the SiOCN thin film is deposited on a three-dimensional structure on the substrate.

3. The method of claim 2 , wherein a wet etch rate ratio of a wet etch rate of SiOCN formed on a substantially vertical surface of the three-dimensional structure to a wet etch rate of the SiOCN formed on a substantially horizontal surface of the three-dimensional structure is more than about 5:1 in 0.5 wt % dilute HF.

4. The method of claim 2 , wherein a wet etch rate ratio of a wet etch rate of SiOCN formed on a substantially vertical surface of the three-dimensional structure to a wet etch rate of the SiOCN formed on a substantially horizontal surface of the three-dimensional structure is less than about 1:2 in 0.5 wt % dilute HF.

5. The method of claim 1 , wherein the silicon precursor comprises (3-aminopropyl)trimethoxysilane (APTMS).

6. The method of claim 1 , wherein the reactive species comprises hydrogen plasma, hydrogen atoms, hydrogen radicals, or hydrogen ions.

7. The method of claim 1 , wherein the reactive species is generated from a second reactant comprising a noble gas.

8. The method of claim 6 , wherein the reactive species further comprises nitrogen plasma, nitrogen atoms, nitrogen radicals, or nitrogen ions.

9. The method of claim 6 , wherein the second reactant comprises H 2 .

10. The method of claim 1 , wherein the substrate surface comprises an organic material.

11. The method of claim 10 , wherein the organic material comprises a photoresist material.

12. The method of claim 1 , wherein a ratio of one or more hydrogen plasma treatment cycles carried out at one or more intervals after a predetermined number of deposition cycles to deposition cycles is from about 1:1 to about 1:10.

13. The method of claim 1 , wherein the at least one reactive species generated by plasma formed from a gas that does not comprise oxygen comprises reactive species generated by a plasma from N 2 .

14. The method of claim 13 , further comprising a second hydrogen plasma deposition step performed after a predetermined number of deposition cycles have been carried out, the hydrogen plasma deposition step comprising at least one cycle comprising:

contacting a surface of the substrate with a vapor phase silicon precursor to on the surface of the substrate;

contacting the adsorbed silicon species with a reactive species generated by plasma formed from H 2 ; and

optionally repeating the contacting steps until a SiOCN film of a desired thickness has been formed;

wherein the silicon precursor has a formula as in one of the following general formulas:

(R I O) 4-x Si(R II —NH 2 ) x   (1)

wherein x is an integer from 1 to 4;

R I is independently selected from the group consisting of alkyl groups; and

R II is independently selected from the groups consisting of hydrocarbon groups;

(R I O) 3 Si—R II —NH 2   (2)

wherein R I is independently selected from the group consisting of alkyl groups; and

R II is independently selected from the group consisting of hydrocarbon groups;

(R I O) 4-x Si(—[CH 2 ] n —NH 2 ) x   (3)

wherein x is an integer from 1 to 4;

n is an integer from 1-5; and

R I is independently selected from the group consisting of alkyl groups.

15. The method of claim 14 , wherein the method is used to form SiOCN spacers on a substrate in a spacer defined double patterning (SDDP) process.

16. The method of claim 14 , wherein the method is used to form SiOCN spacers on a substrate in a spacer defined quadruple patterning (SQDP) process.

17. The method of claim 1 , wherein a reactive species is generated by applying RF power of 100 Watts (W) to about 1000 W to the second reactant.

18. The method of claim 1 , wherein the deposition cycle is carried out at a process temperature of about 300° C. to about 400° C.

19. The method of claim 1 , wherein the deposition cycle is carried out at a process temperature of less than about 100° C.