Selective inhibition in atomic layer deposition of silicon-containing films
Methods of selectively inhibiting deposition of silicon-containing films deposited by atomic layer deposition are provided. Selective inhibition involves exposure of an adsorbed layer of a silicon-containing precursor to a hydrogen-containing inhibitor, and in some instances, prior to exposure of the adsorbed layer to a second reactant. Exposure to a hydrogen-containing inhibitor may be performed with a plasma, and methods are suitable for selective inhibition in thermal or plasma enhanced atomic layer deposition of silicon-containing films.
1. A method of processing semiconductor substrates, the method comprising:
exposing a substrate comprising a feature to a silicon-containing precursor to form an adsorbed layer; and
exposing the adsorbed layer to a hydrogen-containing inhibitor to selectively inhibit deposition of a silicon-containing film on the substrate,
wherein the silicon-containing precursor comprises at least one Si—H bond.
2. The method of claim 1 , wherein deposition is selectively inhibited at a top about 10% of the feature.
3. The method of claim 1 , wherein the hydrogen-containing inhibitor is selected from the group consisting of ammonia, hydrogen, and combinations thereof.
4. The method of claim 1 , further comprising, after exposing the adsorbed layer to the hydrogen-containing inhibitor, exposing the substrate to a second reactant to form the silicon-containing film.
5. The method of claim 4 , wherein the second reactant is selected from the group consisting of nitrogen, nitrogen-containing gases, and oxygen-containing gases.
6. The method of claim 4 , wherein exposing the substrate to the second reactant further comprises igniting a plasma.
7. The method of claim 1 , wherein exposing the adsorbed layer to the hydrogen-containing inhibitor further comprises igniting an in-situ plasma.
8. The method of claim 7 , wherein the silicon-containing film comprises silicon oxide.
9. The method of claim 7 , further comprising, after exposing the adsorbed layer to the hydrogen-containing inhibitor, exposing the substrate to a second reactant to form the silicon-containing film, wherein the second reactant is an oxygen-containing reactant.
10. The method of claim 1 , wherein the adsorbed layer comprises dangling bonds, silicon-silicon dimers, and combinations thereof.
11. The method of claim 1 , further comprising purging a reaction chamber housing the substrate after exposing the substrate to the silicon-containing precursor.
12. The method of claim 1 , wherein the silicon-containing film comprises silicon nitride.
13. The method of claim 1 , wherein the silicon-containing film comprises crystalline silicon, amorphous silicon, or polysilicon.
14. The method of claim 1 , further comprising, prior to exposing the substrate to the silicon-containing precursor, exposing the substrate to an inhibitor.