Etching of GaAs in the Plasma of a Freon R-12–Argon (CCl2F2/Ar) Mixture

Abstract

Halogen-containing plasma, in particular, freons, is frequently used to form the surface topology of semiconductors. In this paper, the kinetics of the interaction between freon R-12 and its mixture with argon and the surface of gallium arsenide (GaAs) are studied. It is established that the initial molecule is completely decomposed into atomic carbon within the studied range of conditions. It is confirmed that chlorine atoms are the main chemically active particles that ensure the etching of GaAs. It is demonstrated that the process of etching occurs in the ion-stimulated chemical reaction regime, where the desorption of products under ionic bombardment plays a substantial part in the purification of the surface. The spectral composition of the plasma-forming medium in the presence of a semiconducting GaAs plate is studied. Some reference lines and bands have been selected for the spectral monitoring of the etching rate by the intensity of the lines and bands of the etching products. In this work, the surface of specimens was monitored on a Solver P47Pro atomic force microscope.