Thin-Layer InAlPSbAs/InAs Heterostructures: Growth Kinetics, Morphology, Structure

Abstract

The results of growing of InAlPSbAs/InAs thin-layer heterostructures by the floating-zone recrystallization with a temperature gradient are discussed. In a model of regular solutions, an analysis of heterophase equilibria in the In–Al–P–Sb–As system is carried out. The growth kinetics is studied as a function of the thickness of the liquid phase (l), and the element concentrations, the substrate temperature (T), and the temperature gradient (G). The growth regimes are investigated and an analysis is carried out for spinodal decompositions of solid solutions. It is shown that the substrate temperature and the temperature gradient have a significant effect on the growth kinetics. Auger electron spectroscopy is used to study the elemental depth profiles of the InAlPSbAs solid solution and show the advantages from liquid phase replenishment to obtain layers of constant composition. The structural perfection of InAlPSbAs solid solutions on an InAs substrate is studied. It is established that the best structural perfection of the layers is achieved at T 873 K, G 20 K/cm, and liquid zone thickness 80 l 120 µm. The surface morphology of InAlPSbAs solid solutions on InAs has been studied by scanning probe microscopy. It is shown that at T 873 K, G 20 K/cm, and liquid zone thickness 80  l 120 µm the root-mean-square surface roughness does not exceed 1 nm.