Optical study of InP etched in methane-based plasmas by reactive ion beam etching

We present an optical characterization of the effect of reactive ion beam etching on InP using a plasma of generated by electron cyclotron resonance discharges. We have studied both semi-insulating (Fe-doped) and -type material (Sn-doped). Raman scattering and photoreflectance have been used to study the evolution of the lattice disruption and the surface electric field as a function of the ion beam voltage, which was varied in the range from 100 V to 600 V. Results indicate that the optimum etching conditions are obtained for an ion beam voltage of about 300 V due to the better relationship between disturbance of the crystal lattice and the etch rate.