Methods of fabricating semiconductor fin structures
Methods of fabricating one or more semiconductor fin structures are provided which include: providing a substrate structure including a first semiconductor material; providing a fin stack(s) above the substrate structure, the fin stack(s) including at least one semiconductor layer, which includes a second semiconductor material; depositing a conformal protective film over the fin stack(s) and the substrate structure; and etching the substrate structure using, at least in part, the fin stack(s) as a mask to facilitate defining the one or more semiconductor fin structures. The conformal protective film protects sidewalls of the at least one semiconductor layer of the fin stack(s) from etching during etching of the substrate structure. As one example, the first semiconductor material may be or include silicon, the second semiconductor material may be or include silicon germanium, and the conformal protective film may be, in one example, silicon nitride.
1. A method comprising:
fabricating one or more semiconductor fin structures, the fabricating comprising:
providing a substrate structure comprising a first semiconductor material;
providing one or more fin stacks above the substrate structure, one fin stack of the one or more fin stacks comprising at least one semiconductor layer including a second semiconductor material;
depositing a conformal protective film over the one or more fin stacks and the substrate structure; and
etching the substrate structure using, at least in part, the one or more fin stacks as a mask to facilitate defining the one or more semiconductor fin structures, wherein the conformal protective film protects sidewalls of the at least one semiconductor layer from etching during the etching of the substrate structure.
2. The method of claim 1 , wherein the second semiconductor material is, at least in part, a different semiconductor material from the first semiconductor material.
3. The method of claim 1 , wherein the second semiconductor material comprises, at least in part, the first semiconductor material.
4. The method of claim 3 , wherein the first semiconductor material comprises silicon, and the second semiconductor material comprises silicon-germanium.
5. The method of claim 1 , wherein the one fin stack of the one or more fin stacks further comprises a hard mask layer above the at least one semiconductor layer, and wherein the conformal protective film covers exposed surfaces of the at least one semiconductor layer and the hard mask layer.
6. The method of claim 5 , wherein the hard mask layer and the conformal protective film comprise a common material.
7. The method of claim 6 , wherein the common material comprises silicon nitride.
8. The method of claim 1 , wherein the conformal protective film has a thickness in a range of about 0.5 nm to 10 nm, where conformally wrapping over the one or more fin stacks.
9. The method of claim 1 , wherein the etching further comprises removing the conformal protective film from over an upper portion of the substrate structure, while leaving the conformal protective film over sidewalls of the one or more fin stacks, and etching at least in part the first semiconductor material of the substrate structure.
10. The method of claim 1 , wherein the fabricating further comprises removing the conformal protective film from sidewalls of the one or more fin stacks subsequent to the etching of the substrate structure.
11. The method of claim 1 , wherein providing the substrate structure comprises providing a multilayer substrate structure, the multilayer substrate structure comprising a semiconductor substrate, a first semiconductor layer disposed over the semiconductor substrate, and a second semiconductor layer disposed over the first semiconductor layer, wherein the semiconductor substrate and the second semiconductor layer comprise the first semiconductor material, and the first semiconductor layer comprises the second semiconductor material.
12. The method of claim 11 , wherein the second semiconductor material comprises, at least in part, the first semiconductor material.
13. The method of claim 12 , wherein the first semiconductor material comprises silicon, and the second semiconductor material comprises silicon germanium.
14. The method of claim 11 , wherein the one fin stack of the one or more fin stacks further comprises a hard mask layer above the at least one semiconductor layer, and wherein the conformal protective film covers exposed surfaces of the at least one semiconductor layer and the hard mask layer.
15. The method of claim 14 , wherein the hard mask layer and the conformal protective film comprise a common material.
16. The method of claim 15 , wherein the common material comprises silicon nitride.
17. The method of claim 11 , wherein the etching comprises etching the first semiconductor layer and the second semiconductor layer of the multilayer substrate structure using, at least in part, the one or more fin stacks as a mask to facilitate defining the one or more semiconductor fin structures.
18. The method of claim 17 , further comprising removing the first semiconductor layer within at least one semiconductor fin structure of the one or more semiconductor fin structures subsequent to the etching of the multilayer substrate structure, thereby defining an opening in the at least one fin structure.
19. The method of claim 18 , further comprising disposing an insulator within the opening in at least one semiconductor fin structure to electrically isolate an upper portion of the at least one semiconductor for structure from the semiconductor substrate.
20. The method of claim 17 , further comprising removing the conformal protective film from sidewalls of the one or more fin stacks subsequent to the removal of the first semiconductor layer from the at least one semiconductor fin structure, and etching at least in part the second semiconductor layer of the multilayer substrate structure.