MOCVD surface preparation of V-groove Si for III-V growth

V-groove nanopatterning of Si substrates has recently demonstrated promise for achieving high-quality III -V-on-Si epitaxy while providing a lower-cost processing route than chemo-mechanical polishing to produce epi-ready planar wafers. A key factor in determining the crystalline quality of III-V buffer layers is the Si surface structure and its chemical composition. Unlike planar Si surfaces, the surfaces of V-grooves prior to growth have not been studied in detail. Here, we study the surface of V-groove Si prepared for GaP nucleation via X-ray photoelectron spectroscopy and low-energy electron diffraction. We identify several pretreatments, using both 830 C and 1000 C annealing under an As background pressure, as being suitable for deoxidizing and cleaning the V-groove Si surface. The V-groove Si was found to behave similarly to reference Si(0 0 1) and Si(1 1 1) planar samples, demonstrating that in situ techniques such as reflection anisotropy spectroscopy can be used on reference samples to infer the state of the V-groove surface, and indicating that the extensive research on planar Si surfaces can be directly applied to V-grooves.

Automated summary

By studying the surface structure and chemical composition of V-groove Si, it is found that different pretreatment methods can be used to deoxidize and clean the V-groove Si surface, demonstrating that the behavior of V-groove Si is similar to that of reference samples of planar Si surfaces, providing a basis for future studies.