SiC epitaxial layer growth in a novel multi-wafer vapor-phase epitaxial (VPE) reactor

Experimental results are presented for SIC epitaxial layer growths employing a unique planetary SIC-VPE reactor. The high-throughput, multi-wafer (7 x 2 ") reactor, was designed for atmospheric and reduced pressure operation at temperatures up to and exceeding 1600 degrees C. Specular epitaxial layers have been grown in the reactor at growth rates ranging from 3-5 mu m/h. The thickest layer grown to date is 42 mu m thick. The layers exhibit minimum unintentional n-type doping of similar to 1 x 10(15) cm(-3), and room temperature mobilities of similar to 1000 cm(2)/V s. Intentional n-type doping from similar to 5 x 1015 cm(-3) to >1 x 10(19) cm(-3) has been achieved. Intrawafer layer thickness and doping uniformities (standard deviation/mean at 1 x 10(16) cm(-3)) are typically 4 and 7%, respectively, on 35 mm diameter substrates. Moderately doped, similar to 4 x 10(17) cm(-3) layers, exhibit similar to 3% doping uniformity. Recently, 3% thickness and 10% doping uniformity (at 1 x 10(16) cm(-3)) has been demonstrated on 50 mm substrates. Within a run, wafer-to-wafer thickness deviation averages similar to 9%. Doping variation, initially ranging as much as a factor of two from the highest to the lowest doped wafer, has been reduced to similar to 13% at 1 x 10(16) cm(-3), by reducing susceptor temperature nonuniformity and eliminating exposed susceptor graphite. Ongoing developments intended to further improve layer uniformity and run-to-run reproducibility, are also presented. (C) 1999 Elsevier Science B.V. All rights reserved.