Collect. Czech. Chem. Commun. 1991, 56, 865-873

Thermodynamic analysis of the deposition of (Ga, Al)As epitaxial layers prepared by the MOCVD technique

Jindřich Leitnera, Petr Voňkab, Jan Mikuleca, Josef Stejskalc and Přemysl Klímac

a Department of Materials for Electronics, Prague Institute of Chemical Technology, 166 28 Prague 6
b Department of Physical Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6
c A. S. Popov Research Institute of Radiocommunication, 142 21 Prague 4


Based on a detailed thermodynamic analysis of the Ga-Al-As-C-H system, starting conditions were determined under with the reaction of trimethylgallium, trimethylaluminium and arsine in hydrogen results in the formation of a single condensed phase, viz. solid (Ga, Al)As. At initial ratios BV/AIII < 1, liquid Ga-Al-As and solid Al4C3 are also formed. At high initial concentrations of the AIII-element alkyl derivatives, solid graphite also emerges, particularly at elevated temperatures and reduced pressures. The calculated composition of the solid (Ga, Al)As is compared with experimental data.