A new degree of freedom in diode optimization: arbitrary axial lifetime profiles by means of ion irradiation

A novel approach to lifetime control in fast recovery power diodes, arbitrary axial lifetime profiles by single-step ion irradiation, is presented. The principle is based on irradiation through a single mask which is inserted between the ion source and the device. The density and lateral/axial structures of the mask determine the final lifetime profile. Experimental results show that this new technique is fully capable to replace multiple single-energy ion irradiations and to guarantee superior diode performance.