Reactive ion etching of Si by Cl and Cl-2 ions: Molecular dynamics simulations with comparisons to experiment

We present results of molecular dynamics simulations of reactive ion etchin g (RIE) of a reconstructed Si(100)(2x1) surface. The existing Stillinger-We ber interatomic potential for Si/Cl of Fell ed al. has been modified by cor recting the Si-Si bond strength for a SiCln moiety bound to a Si surface an d the Si-Cl bond strength in SiClm molecules. This potential has been used to study RTE of Si by Gland Cl-2 ions. The calculated properties such as th e Si yield, product stoichiometry, stoichiometry of the chlorosilyl surface , and Cl content of the chlorosilyl layer are in reasonable agreement with experiment. The dissociative chemisorption probability of Cl-2 on Si(100)(2 X1) as a function of energy has been simulated and the results are in reaso nable agreement with experiment. (C) 1999 American Vacuum Society. [S0734-2 101(99)06104-7].