Etching of GaAs in RIE & CAPE Mode – Characterization of Surface Layer

The etching of GaAs materials under Electron Cyclotron Resonance conditions has been performed in Reactive Ion Etching (RIE) & Chemically Assisted Plasma Etching (CAPE) mode using the CF4+O2 and O2 plasma chemistry. The surface morphology and etch depth were characterized by Scanning Electron Microscopy (SEM) and Dektek 3030ST from Veeco USA respectively. Etching experiments were carried out with change in flow rate, power and dc bias provided the good etching of the surface and fast etch rate. Hence, the surface of the GaAs material displays smooth and stoichiometric surfaces at higher ECR powers. Moreover the film with a complicated composition is grown on the surface during etching, but it does not stop the etching process. At a lower concentration of oxygen in the etching gas mixture, the oxide layer formed on the surface having a high concentration of impurities