CHEMICAL BEAM ETCHING OF INP IN GSMBE

Etching of InP using a beam of PCl3 is demonstrated in a standard gas source molecular beam epitaxy machine. The principle of an atomic laye r accurate endpoint detection technique using in-situ reflection high energy electron diffraction is described and used to study the kinetic s of PCl3 etching. The etch rate is found proportional to the PCl3 flu ence and weakly dependent on the substrate temperature. The morphology of etched surfaces and the etch rate uniformity is compatible with th e regrowth of high quality InGaAsP active structures and with the real ization of etch and regrowth sequences controlled at the nm scale. Etc h profiles at mask edges are defined by nearly perfect crystallographi c facets with a very limited mask undercut (approximate to 100 nm) due to the beam nature of the etching technique.