(100) Microcracks induced by (1 ± 11) stacking faults in halide vapor deposited (001) β-Ga2O3: Origin of reverse leakage current in Schottky barrier diodes observed by high-sensitive emission microscopy and synchrotron x-ray topography

This study reports that microcracks on a halide vapor-phase epitaxy (HVPE)-deposited (001) β-Ga2O3 epitaxial layer are killer defects in Schottky barrier diodes (SBDs). The microcracks are (100) cracks with a typical length of 1.7–5.1 μm and depth of 0.48–2.2 μm. They are accompanied by (111) or (11¯1) stacking faults and dislocation networks, causing a large reverse-leakage-current flow in SBDs. The stacking faults were generated during HVPE growth. The microcracks were considered to be formed by tensile strain caused by the difference in thermal expansion coefficients between the [100] and [010] directions during growth, annealing, etc. The electric field at the bottom of the microcrack was 6.0 MV/cm at −80 V, which resulted in a reverse leakage current in the SBD.