Methods for fabricating integrated circuits having confined epitaxial growth regions

1. A method for fabricating an integrated circuit comprising:

forming a region of a first semiconductor material at least partially bounded by a confinement isolation material to provide a trench;

providing a liner dielectric overlying the confinement isolation material in the trench;

treating the liner dielectric to passivate a surface thereof with functional groups having a higher chemical bond energy and/or lower reactivity than the functional groups of the surface of the untreated liner dielectric; and

growing an epitaxial layer of a second semiconductor material overlying the region of first semiconductor material and filling the trench, wherein growth of the epitaxial layer is nucleated on the surface of the first semiconductor material with little or no nucleation on the liner dielectric due to passivation of the surface of the liner dielectric.

2. The method of claim 1 wherein treating comprises exchanging terminal functional groups at the surface of the liner dielectric.

3. The method of claim 1 wherein treating comprises applying a passivating agent to the surface of the liner.

4. The method of claim 1 wherein treating comprises applying a silane coupling agent to the surface of the liner dielectric.

5. The method of claim 1 wherein treating comprises silylation of the surface of the liner dielectric.

6. The method of claim 1 wherein treating comprises applying a silane coupling agent to the surface of the liner dielectric to change the surface of the liner dielectric from a surface terminating in —OH functional groups to a surface terminating in groups comprising N, H, As, Sb, B, Cl, NH, SH, Ge, CH 2 , or CH 3 .

7. The method of claim 1 wherein treating comprises applying hexamethyldisilazane to the surface of the liner dielectric.

8. A method for fabricating a semiconductor integrated circuit comprising:

providing a semiconductor substrate;

forming a plurality of spaced apart semiconductor fins extending upwardly from the semiconductor substrate;

depositing a surface liner dielectric overlying the semiconductor fins;

depositing an isolation dielectric to fill the spaces between individual ones of the plurality of semiconductor fins, the isolation dielectric and the surface liner dielectric forming confined spaces extending above the plurality of fins;

treating the surface of the surface liner dielectric to passivate the surface thereof with functional groups having a higher chemical bond energy and/or lower reactivity than the functional groups of the surface of the untreated liner dielectric; and

epitaxially growing a crystalline semiconductor material overlying a top portion of the semiconductor fins and filling the confined spaces, wherein growth of the crystalline semiconductor layer is nucleated on the surface of the semiconductor fins with little or no nucleation on the surface liner dielectric due to passivation of the surface of the liner dielectric.

9. The method of claim 8 wherein treating comprises applying hexamethyldisilazane to the surface of the surface liner dielectric.

10. The method of claim 8 wherein treating comprises changing chemical bonds at the surface of the surface liner dielectric to bonds having a stronger bonding energy to reduce reaction of surface bonds with semiconductor source materials during the epitaxial growth.

11. The method of claim 8 wherein treating comprises changing chemical bonds at the surface of the surface liner dielectric to bonds having a different bonding surface energy to reduce reaction of surface bonds with semiconductor source materials during the epitaxial growth.

12. The method of claim 8 wherein treating comprises passivating the surface with gas cluster ion beam treatment.

13. The method of claim 12 wherein treating comprises using a gas cluster ion beam to treat the surface of the surface liner dielectric with an ionized molecule chosen from NF 3 , N 2 /Ar, CH 4 , SiH 4 , CH 3 SiH 3 , CHF 3 , BH 4 , B 2 H 6 , Cl 2 , HCl, TMB, CO 2 , or GeH 4 .

14. The method of claim 8 wherein treating comprises reacting a silane coupling agent with the surface of the surface liner dielectric to cause the surface to be terminated with C, N, or H bonds rather than —OH bonds.

15. A method for fabricating a semiconductor integrated circuit comprising:

forming a plurality of spaced apart semiconductor fins extending upwardly from a semiconductor substrate;

conformally depositing a liner dielectric layer overlying the plurality of semiconductor fins;

depositing an isolation oxide overlying the liner dielectric layer;

exposing a top surface of the plurality of semiconductor fins and a portion of the liner dielectric layer to form confined spaces extending above the plurality of fins;

silylating the exposed surface of the portion of the liner dielectric layer with a silane coupling agent;

epitaxially growing a crystalline material overlying the exposed top surface of the plurality of semiconductor fins and filling the confined spaces, wherein growth of the crystalline material is nucleated on the top surface of the semiconductor fins with little or no nucleation on the liner dielectric layer due to silylation of the exposed surface of the liner dielectric layer; and

etching the isolation oxide and the liner dielectric layer to expose a side portion of the epitaxially grown crystalline material.

16. The method of claim 15 wherein silylating the exposed surface comprises applying a silane coupling agent selected to change surface energy of the exposed surface relative to the surface energy of the untreated exposed surface.

17. The method of claim 15 wherein silylating the exposed surface comprises applying hexamethyldisilazane to the surface of the portion of the liner dielectric layer.

18. The method of claim 15 wherein silylating the exposed surface comprises applying the silane coupling agent by a process chosen from wet chemistry, vapor phase chemistry, or plasma chemistry.