1. Degradation characteristics of gate current and substrate current during stress are studied, and an accurate analytic degradation model of gate current is presented.

2. For the two-dimensional gate current component originated from the subbands in the inversion layers, a transmission calculation is performed.

3. Gate current for pMOSFETs is composed of direct tunneling current, channel hot hole, electron injection current, and highly energetic hot holes by secondary impact ionization.

4. Clearly,[http://] the pressure drop out of the gate current unfavorable impact of the shutdown GTO.

5. But it provides too small emission current density and gives a large gate current.

6. GTO is conventionally driven on a high enough amplitude and steepness with its current leading edge of drive circuit, which applies positive gate current for openness and negative current for shutoff.

7. Once the device begins to conduct , it is latched on and gate current can be removed.

8. The thyristor can be trigged into the on-state by applying a pulse of positive gate current for a short duration provided that the device is in its forward blocking state.

9. For this SMU, the current compliance or measure current value should be set to the highest expected gate current on a fixed measurement range.

10. Once the device begins to conduct, it is latched on and the gate current can be removed.

11. The growth laws of hot carrier damage of PMOSFET's during the hot carrier degradation and the high field annealing are studied by direct gate current measurement.

12. The paper gives the current and voltage waveforms of multi GTO devices at turn-off, analyzes and compares the waveforms of gate current and voltage.