Low-Concentration Deep Traps in 4H-SiC Grown with High Growth Rate by Chemical Vapor Deposition

Epitaxial growth was performed on 8° off-axis 4H-SiC(0001) by horizontal hot-wall chemical vapor deposition (CVD) in a SiH 4 -C 3 H 8 -H 2 system at 1550°C. High growth rates of 10–13 µm/h were attained by growth with a high SiH 4 flow rate of 4.0 sccm. A mirror like surface was obtained by employing an optimum C/Si ratio and by an improved process of initial growth. The epilayers grown with an optimum C/Si ratio showed high purity in the low 10 13 cm -3 range (n-type) and low trap concentrations in the low 10 11 cm -3 range. Minority carrier lifetime was investigated by a differential microwave-detected photoconductance decay (µ-PCD) measurement. A long carrier lifetime of approximately 2 µs was obtained for a 50-µm-thick epilayer