Joint effect of temperature and voltage rise rate on the switching process of Si thyristors triggered in impact ionization wave mode

Abstract

The joint effect of temperature and voltage rise rate in the structure of Si thyristors on the process of their switching to the conductive state by impact ionization wave has been studied by experimental and numerical simulation methods. In the experiments, the rate of voltage rise dV/dt across the structure varies from 0.5 to 10 kV ns −1 , and the temperature varies from 25 °C to 180 °C. It is shown that the main factor determining the nature and parameters of the thyristor switching process is the value of dV/dt. For dV/dt4 kV ns −1 , the impact ionization wave is triggered upon switching of the thyristor at the temperature of the structure up to 180 °C. However, at dV/dt1 kV ns −1 , the wave switching effect disappears when the temperature becomes over ∼110 °C-120 °C. Numerical simulation demonstrates that an increase in the value of dV/dt will increase the electric field in the structure and compensate for the decrease in the intensity of impact ionization processes with increasing temperature.