Preparation of GaAs-Ge and InAs-GaAs Heterojunctions in a Closed Tube System Using Iodine Process

Abstract

Preparation of single crystal heterojuctions is investigated in the vapor growth of GaAs on Ge or of InAs on GaAs substrate by varying their basic growth parameters such as source and substrate temperatures, iodine carrier concentration and crystal orientation. The relations between growth conditions, growth rate and crystal quality are discussed. The most remarkable feature is the appearance of an intermediate layer of 10–20 µ thick between substrate and grown film which is observed over a rather wide range of growth conditions and which plays a fairly important role in junction electrical properties. Experimental results suggested that the origin of this intermediate layer was strongly connected with the species that was once vaporized from the substrate and precipitated in the closed tube.

A Study on Making Abrupt Heterojunctions by Solution Growth

“…Therefore the eutectic solid layer is formed between the recrystallized Ge and GaAs layers when the melt is cooled. In fact, intermediate layers like this have been observed by some researchers (12,13).…”

Optical Characterization of GaAs Layers Grown on Ge Substrates

“…This problem has been investigated in detail in the case of a GaAs-Ge system. The degradation includes misfit dislocations (1), interface alloying (2), autodoping of Ge (3), and the cross diffusions of Ge, Ga, and As (4). The structural quality of these GaAs layers has also been characterized by measurements on electron mobility (5) and the width of an x-ray rocking curve (6), but optical characterization has not yet been reported.…”