Papers by Author: T. Hori

Abstract: Fast homoepitaxial growth of 4H-SiC has been carried out on off-axis (0001) substrates by horizontal hot-wall CVD at 1600οC. High growth rate up to 24 μm/h has been achieved with mirror-like surface in the C/Si ratio range of 1.0-2.0. The Z1/2 and EH6/7 concentrations can be kept as low as 7 × 1011 cm-3 and 3 × 1011 cm-3, although an unknown trap (UT1) is observed with the concentration in the 1011 cm-3 range. The photoluminescence spectra are dominated by strong free exciton peaks, and the L1 peak is not observed. The basal-plane dislocation (BPD) density has decreased with increase in growth rate, and it can be reduced to 22 cm-2 when epilayers are grown on Chemical Mechanically Polished (CMP) substrates at a growth rate of 24 μm/h.

Abstract: Homoepitaxial growth of 4H-SiC and characterization of deep levels obtained mainly in the authors’ group have been reviewed. The growth rate has been increased to 24 om/h with keeping very good surface morphology and low trap concentration on 8o off-axis 4H-SiC(0001) by hot-wall chemical vapor deposition at 1650oC. The increased growth rate has resulted in the enhanced conversion of basal-plane dislocations into threading edge dislocations in epilayers. The Z1/2 and EH6/7 concentrations can be decreased to about 1·1012 cm-3 by increasing the C/Si ratio during CVD. Extensive investigation on as-grown and electron-irradiated epilayers indicates that both the Z1/2 and EH6/7 centers may be attributed to the same origin related to carbon displacement, probably a carbon vacancy. Deep levels observed in as-grown and irradiated p-type 4H-SiC are also presented.