In Situ Observation of Halogen-Transport Atomic Layer Epitaxy of GaAs in Inert Carrier Gas System

Abstract
Atomic layer epitaxy (ALE) using GaCl source in an inert carrier gas system is investigated by means of two in situ monitoring methods: gravimetric method and surface photo-absorption (SPA) method. It is shown that the growth of a monomolecular layer unit occurs in the inert carrier gas system as well as in the H2 carrier gas system. In the SPA measurement, the reflected light intensity during GaCl supply and subsequent inert gas or H2 purge is stronger in the inert carrier gas system than that in the H2 carrier gas system. Based on these results, reaction mechanisms are proposed for the two systems.