Papers by Author: Nobuyuki Yashiro

Abstract: Crystallinity of 4H-SiC bulk crystal obtained by solution growth technique was characterized mainly by KOH etching of the off-ground and serially ground specimen. Marked reduction of basal plane dislocation, threading edge and screw dislocations during the growth of on-axis crystal was confirmed. Cross-sectional TEM observation revealed the rapid reduction behavior of threading dislocations microscopically. AFM observation of as-grown morphology showed that screw dislocation dipoles is related to the reduction of threading screw dislocations and single domain formation, which is essential for establishing the high crystallinity.

Abstract: Solution growth on off-axis 4H-SiC sublimation substrate as a buffer layer for the subsequent CVD epitaxial growth was investigated. Dislocation conversion and propagation from the substrate to the CVD epitaxial layer through the solution grown buffer layer was inspected by molten KOH etch pit observation. Effective dislocation conversion from BPD to TED as an effect of the buffer layer insertion with no drastic change in the total EPD was confirmed.