Uniform deposition of GaAs in a multiwafer vapor-phase epitaxial system

The growth of expitaxial GaAs layers with complex doping structures in a multiple-wafer chloride-transport vapor-phase epitaxial system is reported. The use of kinetically limited growth in a 4-in-diam reaction chamber permits deposition on multiple large substrates with doping and thickness variations less than ±5.5 and ±8 percent, respectively. Solid GaAs sources were used in order to eliminate the complications associated with the saturation of liquid Ga. State-of-the-art single- and double-drift IMPATT materials were grown in this reactor and fabricated devices demonstrated excellent RF performance. The results suggest that it is possible to produce device-quality GaAs in large quantities and at low cost on a routine basis using the well-developed chloride-transport method.