Modeling of silicon carbide epitaxial growth in hot-wall chemical vapor deposition processes

A complete two-dimensional axisymmetric model for chemical vapor deposition (CVD) is presented, incorporating induction heating by a radio frequency coil, flow, heat transfer (radiation included), and gas and surface chemistry, applied to epitaxial growth of silicon carbide (SiC) with H-2 as the carrier gas and C3H8 and SiH4 as precursors. Temperatures range from 1873 and 1923 K. Predictions are compared to full-scale experiments carried out in the Linkoping hot-wall CVD reactor for epitaxial growth. Temperature predictions have previously shown to agree well with experiments; consequently, this paper focuses on the reaction mechanism model. Three different reaction mechanisms are compared to experiments where mechanisms contain 35 gas, seven surface, and two bulk species including gas and surface reactions. The predicted growth rate agrees well with experiments for 300 mbar but is slightly low for 50 mbar and somewhat high for 550 mbar. By including a recent mechanism for decomposition of SiH4, morphological conditions can be predicted comparing partial pressures of Si and C2H2 to experimental data from the literature. The predicted growth rate is not influenced by this additional model. It is demonstrated that when a model for hydrogen etching of the susceptor graphite is included, correct growth limitation is predicted. (C) 2000 The Electrochemical Society. S0013-4651(99)04-017-3. All rights reserved.