Distribution Coefficient of Germanium in Gallium Arsenide Crystals Grown from Gallium Solutions

Abstract

Gallium arsenide crystals doped with germanium were grown from gallium solutions at 900°–875°C. The Ge concentration in the liquid was varied from 0.004 to 56 at.%, and the Ge concentration in the GaAs crystals determined using radiotracer and other techniques. The Ge concentration in the solid varied linearly with increasing Ge concentration in the liquid up to 5 at.% and kGe = (Ges)/(Gel)=0.0083±0.001. Above 5-at.% Ge in the growth solution, kGe increased. At low doping levels Ge acts predominantly as a simple acceptor substituting on arsenic sites. At high doping levels, in the extrinsic range, the Ge concentration in the solid is considerably greater than the free carrier concentration. The form in which the excess Ge exists is not known.

P-Doping Mechanisms in Catalyst-Free Gallium Arsenide Nanowires

“…For single donors and acceptors in GaAs, the impurity concentrations in the semiconductor and in the liquid phase are proportional. Carrier concentrations well above 10 19 cm −3 have been obtained . Following the phase diagram, the solubility of Si in Ga is about ∼1% at 630 °C .…”

“…Carrier concentrations well above 10 19 cm -3 have been obtained. 57 Following the phase diagram, the solubility of Si in Ga is about ∼1% at 630 °C. 58 Two elements determine if the droplet can be a significant pathway of incorporation, with respect to the side facet deposition: i) the steady state concentration at the droplet, given the growth conditions of silicon flux and nanowire growth rate, and ii) the incubation time for this process.…”

Growth mechanism of <100> dark-line defects in high radiance GaAlAs LED's

“…concentration is not proportional to the concentration of Ge atoms (9) , and output power decreased with increase of doping. Therefore the nonradiative recombination defects were presumably introduced during crystal growth.…”

Growth and Evaluation of Epitaxial GaAs for Microwave Devices

“…To insure m i n im u m or zero cross-contamination and compensation, the dopants must have low vapor pressure and low distribution coefficient under the epitaxial growth conditions. Table I compares the vapor pressure (14) and the distribution coefficient of the best k n o w n u n c o m p e nsated dopants of GaAs (7,9,15,16). Sn and Ge have the lowest distribution coefficients and also have vapor pressure m a n y orders of magnitude lower t h a n the other dopants.…”