AVS 45th International Symposium
    Plasma Science and Technology Division Thursday Sessions
       Session PS-ThP

Paper PS-ThP10
Monte-Carlo Simulation of Atomic Scale InP Surface Etching

Thursday, November 5, 1998, 5:30 pm, Room Hall A

Session: Plasma Science and Technology Division Poster Session
Presenter: A. Rhallabi, Institut des Materiaux de Nantes, France
Authors: L. Houlet, Institut des Materiaux de Nantes, France
A. Rhallabi, Institut des Materiaux de Nantes, France
G. Turban, Institut des Materiaux de Nantes, France
Correspondent: Click to Email
Monte-Carlo method has been applied to simulate CH@sub 4@-H@sub 2@ Reactive Ion Etching (RIE) process for an atomic scale InP Surface. Two neutral precursor types and one ion type have been considered in the surface etching process.CH@sub 3@ and H adsorbed precursors are assumed to be bonded to the surface substrate leading to the desorption of the indium and phosphorous sites respectively, while the energetic ions allow the sputtering of the In(CH@sub 3@)@sub x@ and P(H)@sub x@ (0@<=@x@<=@3). XPS analyses show that the ion bombardment gives rise to an amorphous surface. Consequently, the initial InP material was represented by the stoichiometric indium and hydrogen sites which were randomly placed in the 3D discrete network. The model takes account of precursor and site identities, ion preferential sputtering, isotropic transport of neutrals to the surface, adsorption, migration, reaction or desorption of neutrals as well as the independent choice of binding energies between each neutral and site type. The surface migration process is based on the empirical bond-breaking model which is used to determine the amount of energy which must be supplied for a physisorbed precursor to move from one site to another. This process depends on the substrate temperature and the bonded energies for each site type. By setting the available experimental data, the simulation results confirm the surface phosphorous depletion which was observed by XPS analyses. The increase in RMS roughness, the etching rate and neutral surface coverage is obtained when the atomic hydrogen ion flux ratio increases.