Atomic layer deposition of silicon carbon nitride based materials
A process for depositing a silicon carbon nitride film on a substrate can include a plurality of complete deposition cycles, each complete deposition cycle having a SiN sub-cycle and a SiCN sub-cycle. The SiN sub-cycle can include alternately and sequentially contacting the substrate with a silicon precursor and a SiN sub-cycle nitrogen precursor. The SiCN sub-cycle can include alternately and sequentially contacting the substrate with carbon-containing precursor and a SiCN sub-cycle nitrogen precursor. The SiN sub-cycle and the SiCN sub-cycle can include atomic layer deposition (ALD). The process for depositing the silicon carbon nitride film can include a plasma treatment. The plasma treatment can follow a completed plurality of complete deposition cycles.
1. A method for forming a plasma-treated film on a substrate comprising:
depositing a thin film on the substrate by a plurality of deposition cycles each comprising alternately and sequentially contacting the substrate with a first vapor-phase silicon precursor comprising two silicon atoms bound to a hydrocarbon in an Si—R—Si— structure, where R comprises a C 1 to C 8 hydrocarbon, and a second vapor-phase nitrogen reactant; and
subsequently exposing the substrate to a hydrogen-containing plasma generated from a reactant gas that comprises H 2 ,
wherein a ratio of a wet etch rate of the plasma-treated film on the sidewall region of a three-dimensional structure to a wet etch rate of the treated thin film on the top region of the three-dimensional structure is less than 3 as measured in a dilute aqueous solution of hydrofluoric acid having a concentration of 0.5 weight %.
2. The method of claim 1 , wherein the plasma-treated film has a wet etch rate that is less than about 50% of the wet etch rate of thermal silicon oxide, as measured in dilute hydrofluoric acid having a concentration of 0.5 weight %.
3. The method of claim 1 , wherein the plasma-treated film has a wet etch rate of less than about 1 nm/min in a dilute aqueous solution of hydrofluoric acid having a concentration of 0.5 weight %.
4. The method of claim 1 , wherein the plurality of deposition cycles are part of a thermal atomic layer deposition (ALD) process.
5. The process of claim 1 , wherein the thin film is deposited at a temperature of 300 to 600° C.
6. The method of claim 1 , wherein the reactant gas comprises a noble gas.
7. The method of claim 6 , wherein the reactant gas comprises one or more of N 2 , H 2 and Ar.
8. The method of claim 6 , wherein the reactant gas consists of hydrogen gas (H 2 ) and a noble gas.
9. The method of claim 1 , wherein the thin film is exposed to the hydrogen-containing plasma for at least 30 seconds.
10. The method of claim 9 , wherein the thin film is exposed to the hydrogen-containing plasma for at least 10 minutes.
11. The method of claim 1 , wherein the hydrogen-containing plasma is generated by applying RF power from about 100 W to about 500 W to the reactant gas.
12. The method of claim 1 , wherein exposing the thin film to the hydrogen-containing plasma comprises a plurality of cycles in which the plasma is turned on for a first duration of time and turned off for a second duration of time.
13. The method of claim 12 , wherein the duration in which the plasma is turned on differs in two or more cycles.
14. The method of claim 1 , wherein the deposited thin film comprises carbon.
15. The method of claim 1 , wherein the nitrogen reactant comprises a hydrogen atom bonded to a nitrogen atom.
16. The method of claim 1 , wherein the nitrogen reactant is NH 3 .
17. The method of claim 1 , wherein in the silicon precursor R comprises a C 1 to C 3 alkyl chain.
18. The method of claim 1 , wherein the silicon precursor is a halogen substituted silylalkane.
19. The method of claim 1 , wherein the silicon precursor comprises an unsubstituted silylalkane.
20. The method of claim 19 , wherein the silicon precursor comprises bis(silyl)alkane, tris(silyl)alkane or tetrakis(silyl)alkane.
21. The method of claim 1 , wherein the silicon precursor comprises bis(trichlorosilyl)methane (BTCSMe) or 1,2-bis(trichlorosilyl)ethane (BTCSEt).