Two-step kinetics of As/P exchange reaction

A simple two-step mechanism is used to derive the kinetics of the As/P exch ange reaction which takes place on an epitaxially grown InP surface exposed to As flux. The first step involves surface exchange of arsenic with phosp horus, which is then followed by the second step, bulk exchange of arsenic (arsenic incorporation). Two possible choices are investigated for bulk exc hange: the same exchange rate constant in the bulk and the same ratio of ex change rate constants in the bulk. Transient and steady-state profiles of A s composition and the maximum depth of the As/P exchange reaction are deriv ed analytically. (C) 1999 American Institute of Physics. [S0021-8979(99)046 01-0].