THE ALTERED LAYER FORMATION DURING THE REACTIVE ION ETCHING OF GAAS IN CF2CL2-2 PLASMA(O)

The reactive ion etching of GaAs (100) in CF2Cl2+O-2 plasma is reporte d The RF plasma was excited in a diode asymmetrical system with accele rating potential of 30-1500 V, discharge power of 0.5-5.0 W/cm(2) and pressure of 10(-2)-10 Pa. The experimental measurements have shown tha t with the increase of discharge power in plasma the surface becomes d epleted by arsenic and enriched by gallium oxide. The experimental cur ves were modeled by proposed phenomenological model. The model include s the main processes taking place during reactive ion etching: sputter ing, adsorption, heterogeneous chemical reactions, desorption of volat ile compounds and radiation enhanced diffusion. As the balance equatio ns are written for each component in each monolayer the model gives th e kinetics of elemental composition on the surface and the composition of the altered layer. (C) 1998 Elsevier Science Ltd. All rights reser ved.