Methods for depositing III-V compositions on silicon
The present disclosure relates to a method that includes directing a first precursor that includes a Group III element and a second precursor that includes a Group V element to a chamber containing crystalline silicon, where the crystalline silicon includes a substantially planar surface that is patterned with a plurality of v-grooves and the directing results in the forming of a III-V crystal preferentially on a (111) Si surface of the crystalline silicon.
1. A method comprising:
directing a first precursor comprising a Group III element and a second precursor comprising a Group V element to a chamber containing crystalline silicon, wherein:
the crystalline silicon comprises a substantially planar surface that is patterned with a plurality of v-grooves,
each v-groove is characterized by a triangular cross-section defined by a bottom positioned between a first top and a second top,
the bottom and the first top form a first sidewall,
the bottom and the second top form a second sidewall,
each sidewall comprises a (111) Si surface,
the second precursor and the first precursor are provided at a ratio between about 50:1 and about 50,000:1,
the chamber is maintained at a temperature between about 600° C. and about 1000° C., and
the directing results in the forming of a III-V crystal preferentially on the (111) Si surface.
2. The method of claim 1 , wherein the top comprises a silicon surface other than a (111) Si surface.
3. The method of claim 2 , wherein the top comprises a (001) Si surface.
4. The method of claim 1 , wherein the ratio is between about 1,000:1 and about 10,000:1.
5. The method of claim 1 , wherein the temperature is between about 700° C. and about 900° C.
6. The method of claim 5 , wherein the temperature is between about 650° C. and about 850° C.
7. The method of claim 1 , wherein the chamber is maintained at a pressure between about 1 Torr and about 800 Torr.
8. The method of claim 7 , wherein the pressure is between about 500 Torr and about 760 Torr.
9. The method of claim 7 , wherein the pressure is between about 1 Torr and about 100 Torr.
10. The method of claim 1 , wherein the Group III element comprises at least one of gallium, indium, or aluminum.
11. The method of claim 1 , wherein the Group V element comprises at least one of phosphorus, arsenic, or nitrogen.
12. The method of claim 1 , wherein the III-V crystal comprises at least one of GaP, GaAs, InP, InAs, GaAsP, GaNP, or GaInP.
13. The method of claim 1 , further comprising, prior to the directing:
a first initial directing of at least one of arsine (AsH 3 ) or tertiary-butylarsine (TBAs) to the chamber, wherein:
the chamber is maintained at a first initial temperature between 900° C. and 1000° C., and the first initial directing modifies the (111) Si surface.
14. The method of claim 13 , further comprising, after the first initial directing and prior to the directing:
a second initial directing of at least one of phosphine (PH 3 ) or TBAs to the chamber, wherein:
the chamber is maintained at a second initial temperature between 850° C. and 1100° C., and
the second initial directing modifies the (111) Si surface.
15. The method of claim 1 , wherein the III-V crystal coalesces to a conformal coating that covers substantially all of the surface.
16. The method of claim 15 , wherein the conformal coating is substantially planar.
17. The method of claim 16 , wherein the conformal coating comprises GaP.
18. The method of claim 1 , wherein a distance normal to the surface between the top and the bottom defines a depth that is between about 10 nm and 10 μm.
19. The method of claim 1 , wherein a distance between adjacent tops defines a width that is between about 10 nm and 10 μm.
20. The method of claim 17 , wherein the conformal coating has thickness between about 1 nm and 10 μm, as measured from the top of the v-groove to an outer surface of the conformal coating.