Point defects in 4H SiC grown by Halide Chemical Vapor Deposition

摘要

Halide chemical vapor deposition (HCVD) allows for rapid growth while maintaining the purity afforded by a CVD process. While several shallow and deep defect levels have been identified in 6H HCVD substrates using electrical techniques, here we examine several different point defects found in 4H n-type HCVD SiC using electron paramagnetic resonance (EPR) spectroscopy. One spectrum, which exhibits axial symmetry and broadens upon heating, may represent a collection of shallow defects. The other prominent defect has the g tensor of the negatively charged carbon vacancy, but additional hyperfine lines suggest a more complex center. The role of these defects is not yet determined, but we note that the concentrations are similar to those found for the electrically detected defect levels, making them a reasonable source of electrically active centers.