Analysis of the Modifications Induced by Electron Irradiation on the Electrical Characteristics of High Power GTOs

Electron irradiation has been used to modify the electrical characteristics and to enhance the switching speed of high power GTO thyristors. The defects introduced by the impinging electrons have been annealed through several thermal steps, carried out at three different temperatures, after which the main electrical characteristics have been tested. The trade-off between static and dynamic characteristics, obtained with this method of lifetime control, has been compared with that obtained in standard gold doped devices. Special attention is paid to the control of power losses during the turn-off phase.