Effects of Energy Distribution of Interface Traps on Recombination DC Current-Voltage Lineshape

Effects of energy distributions of interface traps in silicon energy gap on recombination DC current-voltage (R-DCIV) characteristics or lineshape are analyzed using Shockley-Read-Hall kinetics. The lineshape is mainly determined by interface traps around silicon midgap, not much affected by the ratio of electron and hole capture rates. On p-type silicon or the p-basewell of inversion n-channel MOS transistor, interface traps above the midgap broaden the lineshape in the accumulation gate-voltage (negative) range, while those below the midgap, the inversion (positive) gate-voltage range. Slater's theory anticipates U-shaped energy distribution of interface traps, which is assumed in this R-DCIV evaluation, showing that the broadened lineshape observed in past experiments, previously attributed to spatial variation of surface dopant impurity concentration, can also arise from energy distribution of interface traps.