Ion beam smoothing of indium-containing III-V compound semiconductors

Reactive ion beam etching (RIBE) with N(2) has been used for smoothing of rough InAs, InP, and InSb surfaces, prepared by argon ion beam etching (IBE). The evolution of the surface roughness and morphology has been studied by atomic force microscopy (AFM) as a function of the N(2) RIBE process parameters lion beam energy, ion beam angle of incidence, and ion dose). A drastic improvement of the surface roughness has been observed for ion beam angles near normal incidence and larger than 70 degrees with increasing ion doses. By using this technique, the initial root-mean-square (rms) roughness of, e.g., InSb of about 40 nm could be decreased to about 1 nm.