Papers by Author: Kunikaza Izumi

Abstract: We investigated the effect of high temperature annealing on the Schottky barrier height (Fb) and the ideality factor (n-factor) of a Mo contact. In a Mo contact, the Fb increased and the leakage current decreased by annealing at 600oC, while no increase in n-factor and forward excess current owing to the high temperature annealing was observed. The Schottky barrier diode with Mo contact annealed at 600oC showed a blocking-voltage (Vb) of 4.15 kV and a specific on resistance (Ron) of 9.07 mWcm2, achieving a high Vb 2/Ron value of 1898 MW/cm2.

Abstract: In this paper, we investigated the density of basal plane dislocations (BPDs) in 4H-SiC epilayers grown on (0001) and (000-1). Re-polishing of the substrate surface, in-situ H2 etching and off-cut angle were found to influence the propagation of BPDs into the epilayers. The epitaxial growth on (000-1) substrates yields a relatively low density of BPDs compared to growth on (0001). The electrical characteristics of pn diodes were also investigated, and the suppressed forward degradation and high-voltage blocking performance were obtained in the use of the (000-1) epilayers.

Abstract: We investigated the structure of the in-grown stacking faults (SFs) in the 4H-SiC epilayers. The in-grown SFs exhibited the photoluminescence (PL) peaks representing phonon replicas with bandgap of 2.710 eV. The in-grown SFs were confirmed to be triangular-shaped by PL mapping and KOH etch pit observation. High-resolution TEM image showed that the in-grown SFs have an identical stacking sequence that differ from single or double Shockley SF. In addition, the density of the in-grown SF depended on growth conditions.