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 comprising:
providing a substrate comprising a first dielectric surface and a second metal 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;
wherein the first precursor adsorbs on the substrate surface and the second reactant reacts with the adsorbed first precursor to selectively form an oxide on the first dielectric surface relative to the second metal surface.
2. The method of claim 1 , wherein the second reactant also reacts with the metal surface to reduce any metal oxide on the metal surface.
3. The method of claim 1 , wherein the second reactant also reacts with the metal surface to remove oxygen from the metal surface.
4. The method of claim 3 , wherein removing oxygen from the metal surface comprises removing OH-groups or oxygen bridges from the metal surface.
5. The method of claim 1 , wherein the dielectric surface comprises SiO 2 .
6. The method of claim 1 , wherein the dielectric surface comprises a low-k material.
7. The method of claim 1 , wherein the metal surface comprises Ru, Co, Cu or W.
8. The method of claim 1 , wherein the oxide is SiO 2 , SiOC or SiOCN.
9. The method of claim 1 , wherein the oxide is a metal oxide.
10. The method of claim 1 , wherein the oxide comprises metal and silicon.
11. The method of claim 1 , wherein the first precursor comprises 3-methoxypropyltrimethoxysilane (MPTMS).
12. The method of claim 1 , wherein the deposition cycle begins with contacting the substrate with the second reactant.
13. The method of claim 1 , additionally comprising contacting the substrate with a third plasma reactant prior to beginning the deposition cycle.
14. The method of claim 1 , wherein the deposition cycle is repeated two or more times to form an oxide film of a desired thickness on the dielectric surface.
15. The method of claim 1 , wherein the metal surface comprises a passivation layer.
16. The method of claim 15 , wherein the passivation layer is an organic passivation layer.
17. The method of claim 16 , wherein the organic passivation layer is selectively deposited on the metal surface relative to the dielectric surface prior to beginning the first deposition cycle.
18. The method of claim 15 , wherein the passivation layer is etched by the second plasma reactant during each deposition cycle.
19. A method of selectively depositing a SiOC thin film on a dielectric surface of a substrate relative to a metal 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.
20. The method of claim 19 , wherein the second reactant is formed by generating a plasma in a gas comprising H 2 and Ar.
21. The method of claim 20 , wherein the plasma is generated using a power of about 30 to 200 W.
22. The method of claim 19 , wherein the PEALD process is carried out at a deposition temperature of about 50 to 300° C.
23. The method of claim 19 , wherein the metal surface comprises Co, Ru, Ni, W, TiN, Cu or Ta.