High temperature annealing effects on deep-level defects in a high purity semi-insulating 4H-SiC substrate

摘要: Effects of high-temperature annealing on deep-level defects in a high-purity semi-insulating 4H silicon carbide substrate have been studied by employing current-voltage, capacitance-voltage, junction spectroscopy, and chemical impurity analysis measurements. Secondary ion mass spectrometry data reveal that the contains boron with concentration mid 1015 cm−3 range, while other impurities including nitrogen, aluminum, titanium, vanadium chromium are below their detection limits (typically ∼1014 cm−3). Schottky barrier diodes fabricated substrates annealed at 1400–1700 °C exhibit metal/p-type semiconductor behavior current rectification up to 8 orders magnitude bias voltages ±3 V. With increasing temperature, series resistance decreases, net acceptor increases approaching content. Admittance spectroscopy results unveil presence shallow acceptors d...