P+IN+ silicon diodes at high forward current densities

Abstract

The current voltage characteristics of silicon junction diodes at high current densities (>100 A/cm 2) are discussed in terms of a two junction P + IN + model. Recombination within the central high resistivity layer and minority carrier injection into both the outer layers are considered, as is the effect of carrier-carrier scattering. It is found that the voltage dropped across the “ I” region is proportional to (current) 1 2 only if the ratio of the thickness of this layer to the diffusion length w/ L is < 1 and if the carrier concentration injected into the “ I” layer is less than 10 16; for injected densities in the range 10 17-10 18, the voltage drop should be proportional to (current) 3 4 , and if w/ L >1, the voltage can increase linearly with current or more rapidly. Probe measurements on sectioned diodes agree reasonably well with the theory.