Substrate and epitaxial issues for SiC power devices

Realization of the full potential of semiconductor SiC for electronic and optical applications is critically dependent on the production of large diameter SiC single-crystals of high crystalline quality and controlled impurity content as well as high quality uniform epitaxial layers. In this paper, current substrate and epitaxial issues are presented in the light of recent results. Progress in monocrystalline SiC bulk crystal growth is characterized by the attainment of substrate diameters up to 100-mm; residual impurities in the 10¹⁵ cm^-3 range; and micropipe densities as low as 1.1 cm^-2 over an entire 50-mm diameter 4H-SiC wafer. Epitaxial growth progress is highlighted by growth rates as high as 50 μm/h, residual impurities of 10¹⁴ cm^-3, and doping uniformities of less than 4.7% in commercial multiwafer reactors. Current materials challenges are the reduction of micropipes, dislocations and dislocation related defects