Patterned growth of gallium arsenide on silicon

The molecular‐beam epitaxial (MBE) growth of GaAs on silicon through openings in an oxide or nitride mask is an attractive alternative to the conventional full wafer deposition of GaAs on silicon for the monolithic integration of GaAs and Si devices. We have investigated techniques for the patterned growth of GaAs on Si and have found that single‐crystal GaAs regions of high‐crystalline quality can be successfully grown on silicon substrates. When the MBE growth is performed through holes in a mask onto the original planar silicon surface, the GaAs transformed from polycrystalline to single‐crystal growth directly above the termination point of the wet etched oxide mask. Postgrowth annealing was found to drastically change the defect structure by causing single‐crystal overgrowth of the mask, an elimination of the transition region defects, and significant grain growth in the remaining polycrystalline GaAs. Growth within etched trenches in the Si substrate also produced GaAs of good crystalline quality, a...