A new low loss high power GTO with low snubber capacity

A novel low-loss, high-power GTO (gate turn-off thyristor) which has a blocking voltage of 4.5 kV and a current capability of 4 kA with a snubber capacity of 5 mu F has been developed. A narrow n-emitter stripe whose width is reduced 35% compared with conventional GTO and de-alloy technology were adopted for this GTO. The de-alloy technology that is used here has no alloying process and realizes improved uniformity of the pressure distribution, as well as optimization of the impurity diffusion profile, leading to an improved tradeoff between turn-on and turn-off characteristics. Using these technologies, snubber capacity was reduced 17%, turn-on switching loss was reduced 50%, and turn-off switching loss was reduced 20% compared with the conventional GTO.<>