V. A. Moskovkin

Influence of thermal processing on the properties of Sn-doped GaAs epitaxial layers

The influence of annealing at a temperature of 750–830°C on the electrophysical, luminescent, and structural characteristics of GaAs layers doped with various concentrations of tin is studied. It is shown that, for low doping levels, the layers possess properties with high thermal stability. During annealing, one observes a lowering of the concentration of electrons, a reduction of the lattice periodicity, and a change in the photoluminescence spectra of strongly-doped layers, which is explained by the process of the formation of complexes and by the decomposition of supersaturated solid solutions of impurity dopants.

Kinetics of capture of tellurium by {111} gallium arsenide faces in the GaAs-AsCl3-H2 system at various supersaturations

ConclusionsFrom our investigations it follows that the dependence of the tellurium capture rate on supersaturation in the GaAs(Te)-ASCl3-H2 system can be explained:a)in the region of low supersaturations, on the basis of the surface-diffusion model withλsiλs0<1 on (111)B andλsi/λs0>1 on (111)A;b)in the region of high supersaturations, on the basis of a model that takes account of the decrease in the density of sites of impurity-atom incorporation into a step because of contamination of the contamination of the steps with chlorine.

Effects of growth temperature and substrate orientation on the entry of tellurium into epitaxial gallium arsenide films

Measurements have been made on the electrophysical properties and rate of tellurium uptake in epitaxial films of gallium arsenide grown at various temperatures (600–800°C) on GaAs substrates of principal and vicinal orientations. The activation energy for tellurium uptake has been determined and the rate-limiting stages for various faces have been examined.

Influence of crystallization temperature on the structure of growth surfaces of epitaxial gallium arsenide layers in the system GaAs-AsCl3-H2

ConclusionsThus, joint analysis of data on the growth rate and the structure of the growth surface of epitaxial GaAs layers made it possible to obtain quantitative characteristics of the surface processes (tangential velocity of steps, average diffusion length of adsorbed particles, reaction time at a kink, density and average height of growth steps) and their dependence on the deposition temperature. The absence of qualitative changes in the microrelief in the passage from region I to region II [1] confirms that the two ranges of temperatures are kinetic while the motion of the growth steps is controlled by surface processes. For the 〈111〉A pole this consists primarily of surface-diffusion limitations while for the 〈111〉B consists of limitations on the reaction rate at the steps.

Influence of crystallization temperature on growth rate of epitaxial gallium arsenide layers in the system GaAs-AsCl3-H2

ConclusionsThus, consideration of the temperature dependences of the growth rate of singular and vicinal GaAs faces made it possible to determine the activation energy of the growth process in the kinetic region, to demonstrate the changes in the activation energy on passing from singular to vicinal faces, to estimate the magnitude of these changes, and also to analyze some distinctive features of the crystallization process which are related to the crystal chemistry of growing planes. The growth of GaAs epitaxial layers near the <111>B and <001> poles over a wide range of deposition temperatures is limited by the rate of the surface stage while for layers grown on substrates near the <111>A and <110> poles at high temperatures a significant role is played by outward-diffusion limitations which are associated primarily with the arsenic supply.

Influence of supersaturation on the growth of gallium arsenide films in chloride gas-transport systems

An experimental investigation was made into the growth kinetics and relief of the growth surface for the (111)A, (111)B, (110), and (001) planes of gallium arsenide for different degrees of supersaturation determined by the difference between the temperatures of the source and the substrate. The obtained dependences are interpreted on the basis of the basic conclusions of the theory of the growth of crystals.