Numerical analysis of growth kinetics of bulk III‐V crystals grown by liquid phase electroepitaxy

Abstract

AbstractResults of time‐dependent simulations of growth of bulk binary III–V crystals by current controlled liquid phase electroepitaxy (LPEE) are presented using GaAs as example. Without any electrical current the LPEE system is isothermal, kept at 1073 K, thus no growth occurs. The electric current density of 10 A/cm2 leads to ohmic heating of the entire system, Peltier cooling of the Ga‐GaAs(seed) interface and electromigration of As species in liquid Ga. Neither Peltier nor Joule effects are considered at the source/solution interface since in the configuration chosen the electric current bypasses the source crystal. The Peltier‐induced cooling and electromigration of As induce growth of GaAs, originally at the rate of 0.5 μm/min. As the growth proceeds, the Peltier cooling is overcompensated by Joule heating, which leads to the reduction of growth rate and finally to standstill. It is shown that the LPEE growth is strongly time dependent, leading to the change of crystallization front, reflecting the fastest growth rate at the center of the crucible and the slowest, close to the crucible wall. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)