Interface Effects with Ga0.47In0.53As Layers on InP Substrates Prepared by Organometallic Chemical Vapor Deposition

Lattice-matched Ga0.47In0.53As was epitaxially grown on InP substrates by the reaction of triethylgallium, triethylindium and arsine. The mobility and carrier concentration in these layers were determined by sequential etch and Hall effect measurements made on the grown layers. These measurements show a considerable fall–off in mobility in the vicinity of the interface, accompanied by a rapid increase in electron concentration. In situ chloride etching of the substrate, prior to Ga–In–As growth, is shown to reduce significantly but not eliminate these interface effects. In this paper we outline possible reasons for these effects, based on measurements made on films grown with and without substrate etching and also on measurements of the effect of etching on the substrate itself.