Turn off time/on-resistance trade-off control with electron irradiation as related to power switching BSITs

Experimental data on the effect of electron irradiation and annealing on the electric characteristics of high voltage bipolar mode power static induction transistors (BSITs) are given. The anneal behaviour of radiation-induced defects in active areas of BSITs is discussed. A criterion of preference for centers, which controls lifetimes is suggested. The criterion of preference fits the A-center. In addition, it is shown that the processing gives best improvement of the characteristics, when the phosphorus impurity concentration greatly exceeds the oxygen concentration in the heavily-doped Si substrate and oxygen content much exceeds carbon content in the epilayer