Two-step kinetics of As/P exchange reaction

Abstract

A simple two-step mechanism is used to derive the kinetics of the As/P exchange reaction which takes place on an epitaxially grown InP surface exposed to As flux. The first step involves surface exchange of arsenic with phosphorus, which is then followed by the second step, bulk exchange of arsenic (arsenic incorporation). Two possible choices are investigated for bulk exchange: the same exchange rate constant in the bulk and the same ratio of exchange rate constants in the bulk. Transient and steady-state profiles of As composition and the maximum depth of the As/P exchange reaction are derived analytically.