Selective PEALD of oxide on dielectric
Methods for selectively depositing oxide thin films on a dielectric surface of a substrate relative to a metal surface 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 first precursor comprising oxygen and a species to be included in the oxide, such as a metal or silicon, and a second plasma reactant. In some embodiments the second plasma reactant comprises a plasma formed in a reactant gas that does not comprise oxygen. In some embodiments the second plasma reactant comprises plasma generated in a gas comprising hydrogen.
1. A plasma enhanced atomic layer deposition (PEALD) process for selectively depositing an oxide on a dielectric surface of a substrate relative to a TiN surface comprising:
providing a substrate comprising a dielectric surface and a TiN surface;
conducting at least one deposition cycle comprising alternately and sequentially contacting the substrate with a first silicon precursor comprising oxygen and a second reactant comprising reactive species from a plasma generated in a gas comprising hydrogen and not oxygen.
2. The process of claim 1 , wherein the first precursor adsorbs on the dielectric surface and the second reactant reacts with the adsorbed first precursor to selectively form the oxide on the dielectric surface relative to the TiN surface.
3. The process of claim 2 , wherein the second reactant also reacts with the TiN surface to reduce any metal oxide on the TiN surface.
4. The process of claim 2 , wherein the second reactant also reacts with the TiN surface to remove oxygen from the TiN surface.
5. The process of claim 4 , wherein removing oxygen from the TiN surface comprises removing OH-groups or oxygen bridges from the TiN surface.
6. The process of claim 1 , wherein the dielectric surface comprises SiO 2 .
7. The process of claim 1 , wherein the dielectric surface comprises a low-k material.
8. The process of claim 1 , wherein the oxide is SiO 2 , SiOC or SiOCN.
9. The process of claim 1 , wherein the oxide is a metal oxide.
10. The process of claim 1 , wherein the oxide comprises metal and silicon.
11. The process of claim 1 , wherein the first silicon precursor comprises 3-methoxypropyltrimethoxysilane (MPTMS).
12. The process of claim 1 , wherein the deposition cycle begins with contacting the substrate with the second reactant.
13. The process of claim 1 , additionally comprising contacting the substrate with a third plasma reactant prior to beginning the deposition cycle.
14. The process of claim 1 , wherein the deposition cycle is repeated two or more times to form the oxide of a desired thickness on the dielectric surface.
15. The process of claim 1 , wherein the TiN surface comprises a passivation layer.
16. The process of claim 15 , wherein the passivation layer is an organic passivation layer.
17. The process of claim 16 , wherein the organic passivation layer is selectively deposited on the TiN surface relative to the dielectric surface prior to beginning the deposition cycle.
18. A method of selectively depositing a SiOC thin film on a dielectric surface of a substrate relative to a metal nitride surface of the substrate by a plasma enhanced atomic layer deposition (PEALD) process comprising alternately and sequentially contacting the substrate with a first reactant comprising silicon and oxygen and a second reactant comprising plasma generated in a gas comprising hydrogen and not oxygen.
19. The method of claim 18 , wherein the second reactant is formed by generating a plasma in a gas comprising H 2 and Ar.
20. The method of claim 19 , wherein the metal nitride surface comprises TiN or TaN.