Effect of Intrinsic Defects in High-Purity Semi-Insulating 4H-SiC on Reverse Current–Voltage Characteristics of Schottky Barrier Diodes

Abstract

Schottky barrier diodes are fabricated using high-purity semi-insulating 4H-SiC. Under certain measurement conditions, the reverse current–voltage (IR–V) characteristics of the diodes exhibit a peak, with the diodes appearing to behave as negative resistance diodes. To investigate the effect of intrinsic defects in the 4H-SiC on the IR–V characteristics, the transient reverse currents of the diodes are measured. Without any assumptions regarding defects, a graphical peak analysis method, discharge current transient spectroscopy (DCTS), which uses the isothermal transient reverse current, can determine the densities and emission rates of defects. From simulation of the IR–V characteristics using the densities and emission rates of intrinsic defects determined by DCTS, the effect of the intrinsic defects in high-purity semi-insulating 4H-SiC on the IR–V characteristics of its Schottky barrier diodes is elucidated. It is found that DCTS is suitable for determining the densities and emission rates of electrically active defects in semi-insulating semiconductors.