Nanoheteroepitaxy for the integration of highly mismatched semiconductor materials

We describe an ongoing study of nanoheteroepitaxy (NHE), the use of nanoscale growth-initiation areas for the integration of highly mismatched semiconductor materials. The concept and theory of NHE is briefly described and is followed by a discussion of the design and fabrication by interferometric lithography of practical sample structures that satisfy the requirements of NHE. Results of NHE growth of GaAs-on-Si and GaN-on-Si are described, following the NHE process from nucleation through to coalescence. Micro-Raman measurements indicate that the strain in partially coalesced NHE GaN-on-Si films is <0.1 GPa.