Use of Vanadium Doping for Compensated and Semi-Insulating SiC Epitaxial Layers for SiC Device Applications

摘要

Vanadium doping from SiCU source during epitaxial growth with chlorinated C and Si precursors was investigated as a mean of achieving compensated and semi-insulating epitaxial 4H-SiC layers for device applications. Thin epilayers were grown at 1450°C with a growth rate of ~6 um/h. Experiments at 1600°C resulted in the growth rates ranging from 60 to 90 μm/h producing epilayers with thickness above 30μm. V concentrations up to about 10~(l7)cm~(-3) were found safe for achieving defect-free epilayer surface morphology, however certain degradation of the crystalline quality was detected by XRD at V concentrations as low as 3-5×l0~(15) cm~(-3). Controllable compensation of nitrogen donors with V acceptors provided low-doped and semi-insulating epitaxial layers. Mesa isolated PiN diodes with V-acceptor-compensated n" epilayers used as drift regions showed qualitatively normal forward- and reverse-bias behavior.