Scaling of Chlorosilane SiC CVD to Multi-Wafer Epitaxy System
A SiC epitaxy process based on chlorosilane/propane chemistry has been successfully transferred from a single-wafer R&D system to a multi-wafer CVD reactor. The optimized process results in very smooth epi surface (RMS~0.24nm) and minimum surface pits (less than 0.5/cm2). Both n-type and p-type doping in a wide range are demonstrated using nitrogen and aluminum, respectively. The high performance benchmarks for thickness uniformity (intra-wafer variation <1% and inter-wafer variation <1%) and doping uniformity (intra-wafer variation <6% and inter-wafer variation <3%) are achieved on 5 x 3-inch wafers. The carrier lifetime in these epilayers measured by μ-PCD is over 5 μs, the longest value reported so far for SiC epitaxial wafers.
N. Wright, C.M. Johnson, K. Vassilevski, I. Nikitina and A. Horsfall
J. W. Wan et al., "Scaling of Chlorosilane SiC CVD to Multi-Wafer Epitaxy System", Materials Science Forum, Vols. 556-557, pp. 145-148, 2007