REACTIVE ION-BEAM ETCHING OF INSB AND INAS WITH ULTRASMOOTH SURFACES

The reactive ion beam etching (RIBE) of InSb and InAs using N-2-Ar mix tures was investigated as a function of the gas mixture, ion beam ener gy, ion beam current density and etching time, It has been shown that with increasing N-2:Ar ratio the morphology of the etched surfaces bec omes very smooth. For an ion beam energy of 500 eV the surface roughne ss (root mean square) of InSb was reduced by more than 2 orders of mag nitude because of the utilization of N-2 instead of Ar at moderate etc hing rates, Furthermore, in contrast to pure Ar sputtering, no increas ing surface roughness with increasing etching time was observed for th e N-2 RIBE process.