Development of multiwafer warm-wall planetary VPE reactors for SiC device production

The development of SiC vapor phase epitaxial (VPE) growth for advanced SiC device production is reviewed with an emphasis on multiwafer reactors. Initially SiC epitaxial growth was performed in small homemade reactors on tiny, several millimeter on a side SiC crystals. While interest in SiC has its origins in the late 1950s, along side the elemental semiconductors Si and Ge, its technological development has been delayed by the extreme temperatures (similar to 1600 degrees C) required to grow SiC epitaxial layers, the late development of suitable substrates, and the various polytypes that can form. In large part these challenges have now been overcome. The most recent SiC epitaxial layer growth results, including those from the highest reported throughput, 8 x 100 mm, warm-wall planetary SiC-VPE reactor, are presented in detail. The growth of device-quality SiC epitaxial layers with low background doping concentrations <1 x 10(14) cm(3), and intentional p- and n-type doping from similar to 1 x 10(15) cm(-3) to >1 x 10(19) cm(-3) will be described. These layers have intrawafer thickness and n-type doping uniformity (sigma/mean) of similar to 2% and similar to 8%. The total range of the average intrawafer thickness and doping within a run are approximately +/-1 % and +/-6 %, respectively. Long term run-to-run variations (sigma/mean) while under process control are currently similar to 3 % for thickness and similar to 5 % for doping. Multiwafer SiC epitaxial layer throughput has been increased by over a factor of twenty in just the past seven years while achieving these desirable layer characteristics. This new epitaxial capability is enabling the economical production of advanced SiC devices for the marketplace.