Method for Estimating Accurate Deep-Trap Densities from DLTS of Junctions Containing Several Kinds of Deep-Traps

The density of a deep trap is estimated from the peak height of the DLTS signal and the steady-state capacitance on a reverse-biased semiconductor junction. When several kinds of traps exist in the depletion region and the trap densities are not much smaller than the net shallow-level density, a considerable error appears in the trap-density estimations. For such a case, it is necessary to solve exactly Poisson's equation for the depletion region in transient sequence to deduce the trap densities. A method for accurate trap-density evaluation is introduced, and the results of the analysis for the DLTS spectrum of a gold-doped n -type silicon Schottky diode are discussed.