Helium Implantation for Lifetime Control in Silicon Power Devices

The concentration profile of defect centres in silicon induced by ¿-particle irradiation, is investigated using deep level transient spectroscopy and spreading resistance measurements. As in the case of proton irradiation, a buried recombination centre doped layer is created in the penetration depth of the particles. In contrast to proton irradiations, after annealing of ¿ particle irradiated samples no shallow donor doped layers are observed, which can severely affect the breakdown voltage of power devices.