28 - Silicon Carbide Epitaxy

Abstract

Epitaxial growth is used to produce active layers of silicon carbide (SiC)-based device structures with designed doping density and thickness, because control of doping and thickness in bulk growth is difficult. Homoepitaxial growth technology by chemical vapor deposition has shown remarkable progress, with polytype replication and reliable control of a wide range of doping densities (1014–1019/cm3) in both n- and p-type materials. This was achieved using step-flow growth and controlling the carbon/silicon ratio, respectively. The gas phase and surface reactions can be well simulated even at a very high growth temperature (∼1600°C). Types and structures of major extended and point defects in SiC epitaxial layers have been investigated, and the basic phenomena of defect generation and reduction during SiC epitaxy have been clarified. In this chapter, the fundamental aspects and technological developments involved in hexagonal SiC homoepitaxial growth are described.