Accurate calculations of the forward drop and power dissipation in thyristors

Four-layer power thyristors are analyzed using exact numerical solutions of the full set of semiconductor device equations together with the heat-flow equation. Included in the analysis are the physical mechanisms of carrier-carrier scattering, Auger and SRH recombination, and band-gap narrowing. The experimental current-voltage curves for three-thyristor structures are compared with the theoretical predictions and are shown to be in good agreement. The limiting effects on device behavior of the physical mechanisms noted above, including heat-sink thermal impedance, are investigated over the range of device operating conditions. The distribution of power dissipation throughout the device is shown and compared with the distribution of recombination in the device. The theory of calculating power dissipation in a semiconductor is also discussed.