Formation of SiOCN thin films
Methods for depositing silicon oxycarbonitride (SiOCN) thin films on a substrate in a reaction space are provided. The methods can include at least one plasma enhanced atomic layer deposition (PEALD) cycle including alternately and sequentially contacting the substrate with a silicon precursor and a second reactant that does not include oxygen. In some embodiments the methods allow for the deposition of SiOCN films having improved acid-based wet etch resistance.
1. A plasma enhanced atomic layer deposition (PEALD) method of forming a thin film comprising silicon, oxygen and carbon on a substrate in a reaction space, wherein the PEALD method 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; and
contacting the adsorbed silicon species with at least one reactive species generated by plasma formed from gas that does not comprise oxygen,
wherein the silicon precursor comprises a silicon atom, an alkoxide group bonded to the silicon atom and an amino group; and
wherein the substrate is not contacted with oxygen-containing reactive species generated from gas.
2. The method of claim 1 further comprising repeating the deposition cycle until the thin film comprising silicon, oxygen and carbon of a desired thickness has been formed.
3. The method of claim 1 , wherein the silicon precursor comprises a carbon chain which is bonded to silicon through carbon.
4. The method of claim 3 , wherein the carbon chain comprises atoms other than carbon and hydrogen.
5. The method of claim 1 , wherein the amino group is bonded to the silicon atom through a carbon.
6. The method of claim 1 , wherein the thin film comprises up to 10 at % nitrogen.
7. The method of claim 1 , wherein the thin film comprises at least 20 at % oxygen.
8. The method of claim 1 , wherein the thin film comprises at least 5 at % carbon.
9. The method of claim 1 , wherein a ratio of a wet etch rate of the thin film to a wet etch rate of thermal silicon oxide is less than about 5.
10. The method of claim 1 , wherein the thin film is deposited on a three-dimensional structure.
11. The method of claim 10 , wherein a wet etch rate ratio of a wet etch rate of the thin film formed on a top surface of the three-dimensional structure to a wet etch rate of the thin film formed on a sidewall surface of the three-dimensional structure is about 1:1 in dilute HF.
12. The method of claim 1 , wherein the silicon precursor does not comprise a halogen.
13. The method of claim 1 , wherein the substrate comprises a metal, metal nitride, metal carbide, or metal chalcogenide surface.
14. The method of claim 1 , wherein the substrate comprises an organic material.
15. The method of claim 1 , wherein the reactive species comprises hydrogen plasma, hydrogen atoms, hydrogen radicals, or hydrogen ions.
16. The method of claim 15 , wherein the reactive species further comprises nitrogen plasma, nitrogen atoms, nitrogen radicals, or nitrogen ions.
17. The method of claim 1 , wherein the reactive species is generated from a second reactant comprising a noble gas.
18. The method of claim 1 , wherein the reactive species is generated by plasma from a second reactant comprising hydrogen.
19. The method of claim 18 , wherein the second reactant comprises H 2 .
20. The method of claim 1 , wherein the deposition cycle is carried out at a process temperature of less than about 100° C.