Crystal defects observed by the etch-pit method and their effects on Schottky-barrier-diode characteristics on ((2)over-bar01) β-Ga2O3

A pixel array of vertical Schottky-barrier diodes (SBDs) was fabricated and measured on the surface of a ((2) over bar 01) beta-Ga2O3 single crystal. Subsequently, etch pits and patterns were observed on the same surface. Three types of etch pits were discovered: (1) a line-shaped etch pattern originating from a void and extending toward the [010] direction, (2) an arrow-shaped etch pit whose arrow's head faces toward the [102] direction and, (3) a gourd-shaped etch pit whose point head faces toward the [102] direction. Their average densities were estimated to be 5 x 10(2), 7 x 10(4), and 9 x 10(4) cm(-2), respectively. We confirmed no clear relationship between the leakage current in SBDs and these crystalline defects. Such results are obtained because threading dislocations run mainly in the [010] growth direction and do not go through the ((2) over bar 01) sample plate. (C) 2017 The Japan Society of Applied Physics