GTO thyristor optimisation

On-state voltage and energy lost during device switching are two of the key parameters in GTO thyristor design and operation. The trade-off between on-state voltage (V/sub TM/) and energy lost during device turn-off (E/sub off/) for a GTO thyristor is explained, and examined using lifetime control methods. Three methods are considered electron irradiation, proton irradiation and gold diffusion. Electron irradiation is examined in detail and it is shown that optimised V/sub TM/-E/sub OFF/ may be achieved for any combination of duty cycle and frequency thus providing the circuit designer with minimised average power dissipation during device operation. A comparison is made with gold diffusion and proton irradiation. From these results a suitable process is selected for lifetime control of 1200V, 300A GTO thyristors.<>