Simulation of the large-area growth of homoepitaxial 4H-Sic by chemical vapor deposition

Abstract
The growth of thick epitaxial 4H-SiC layers with low defect density is an essential step for the fabrication of SiC based devices. Cold- and hot-wall reactors using silane and propane diluted in hydrogen were used in this study. The typical growth temperature range is 1700-1900 K and total pressure range 10-100 kPa. The resulting epilayers exhibit low background doping, low defect density and good thickness uniformity. The main problem is that it is difficult with this first generation of reactors to ensure a good uniformity of deposition over large wafer dimension. A 3D simulation approach of heat and mass transfer was used with two objectives. The first one is to evaluate the electrical, thermal, transport and kinetic databases. The second one is to have a visualization and a quantification of the flow, temperature and gaseous species fields for a better understanding of engineering problems at elevated temperatures.