Misfit dislocation generated in InAs epilayer and InP substrate interfaces grown by metalorganic chemical-vapor deposition

Abstract

The properties of InAs epilayer grown on (001) InP substrates (oriented 2degrees off (001) toward the [110] direction) using metaorganic chemical-vapor deposition (MOCVD) are reported. The epilayer of 17 nm thickness grown at 405 degreesC showed three kinds of misfit dislocation arrays. Their Burgers vectors in all cases were of the form a/2<101> inclined 45 to the interface. Upon annealing 600, 140 and 220 nm InAs epilayers at 660 degreesC, most misfit dislocations became Lomer-type oriented exactly along the <110> direction. Average distance between misfit dislocations at early stage of growth was inversely proportional to the InAs thickness. This phenomena was interpreted to the relationship between the dislocation interaction energy and residual InAs epilayer strain energy. (C) 2002 Elsevier Science B.V. All rights reserved.