Ultra-thin strain-relieving si1-xgex layers enabling iii-v epitaxy on si

Abstract

Example methods, compositions and structures are presented whereby sub-10-nm-thick strain-relieving Si1-xGex layers can be realized by Ge ion implantation, into, and selective oxidation of, Si(111) wafers. The resulting Ge-rich layers are fully strain relaxed via a network of misfit dislocations at the Si/Si1-xGe, interface, which do not propagate through the Si1-xGex film. The dislocation network has been found to coincide with a periodic variation in the composition at the Si/Si1-xGex interface and is believed to result from the defect-medicated diffusion of Si atoms from the Si substrate through the Si1-xGex layer to the above SiO2 layer. The epitaxial growth of GaAs on such ultra-thin substrates is demonstrated, presenting a promising approach for solving the long-standing challenge of local, monolithic integration of III-V optoelectronics on the Si platform.

Dependencies are inferred from the claim text.