Concentration of Zinc in Gallium Arsenide Crystals Grown by Slowly Cooling Gallium-Rich Solutions

Abstract

Gallium arsenide crystals were grown from Ga‐rich solutions having initial compositions near the 900°C isotherm of the Ga‐As‐Zn ternary phase diagram. They were grown over the temperature range from 900° to 700°C. The concentration of Zn in normalGaAs appears to vary linearly with the Zn atomic fraction in the liquid at lower doping levels and with the square root of the atomic fraction of Zn in the liquid at higher doping levels. In fitting the experimental data to the theoretical expression for the solid solubility, the intrinsic carrier concentration of normalGaAs was found to be about 8×1017 cm−3 . The corresponding temperature has been estimated to be 825°–850°C.

Nonequilibrium in Substitutional‐Interstitial Diffusion of Zn in GaAs at 850°C

“…By the procedure illustrated in the preceding sect/on, it was verified that this quantity of GaAS (corresponding to an AS content of about 5-6 a/o) was necessary to reach the equilibrium composition of the source at the diffusion temperature, so as to have an As saturated source. This agrees with published experi- mental data about the ternary phase diagram GaAsZn (9).…”