Heat Treatment Centers and Bulk Currents in Silicon <i>p-n</i> Junctions

Abstract

A set of small-area, alloy, p-n junction diodes was made from a slice of heat-treated n-type silicon. The carrier lifetimes of the diodes were found to be in the range of 2.5×10−8 sec to 3.5×10−6 sec. Measurements were made of the lifetime and of the current-voltage characteristics in the forward and reverse directions as a function of temperature from room temperature to 165°C. An analysis of the results and, in particular, the correlation of current flow with lifetime values, showed that for the diodes with the shortest lifetimes, centers situated 0.48 ev at 0°K from either the conduction or valence bands were responsible for large space-charge currents. For the diodes with lifetimes in the microsecond range, surface leakage currents were predominant. Evidence was found of a field-dependent emission probability, β, for these centers. The results showed that β∼E0.35 when E, the electric field, is in the range of 2×104 to 8×104 v/cm.