Single-Crystal GaAs and GaSb on Insulator on Bulk Si Substrates Based on Rapid Melt Growth

A high-quality III-V material on Si substrates has been a primary goal for ultimate device integration. By using the rapid melt growth (RMG) method, we have demonstrated the transformation of amorphous to single crystal for both GaAs and GaSb on bulk Si substrates. High-resolution pictures and selective area diffraction patterns show single-crystal films directly seeded from the Si substrate and propagated along the patterned stripes on top of the insulating layer. Energy-dispersive X-ray spectroscopy was applied to investigate the stoichiometry of the compound material after resolidification. The results show a direct relationship between crystal quality and atomic composition, which suggests a congruent growth for the III-V material during the solidification process despite the possibility of out gassing during the RMG process. This provides a simple path for monolithic optical-electrical integration.