| 摘要 |
The insulated gate bipolar transistor (IGBT) integrates an anti-excess voltage protection function and a drain voltage fixing function. When a voltage is applied across the drain electrode and the source electrode of the IGBT to propagate a depletion zone from a p-n junction between a p base layer and a n<-> drain layer toward inside of the n<-> drain layer, a critical electric field is established that causes generation of a great number of electron-hole pairs due to impact ionization of carriers in or near the n<-> drain layer, thereby causing conduction between the drain electrode and the source electrode, at an applied voltage lower than a drain-source voltage at which said depletion region reaches a p<+> drain layer through the n<-> drain layer, the applied voltage being equal to or lower than a critical voltage that causes generation of a great number of electron-hole pairs due to impact ionization of carriers in or near the n<-> drain layer below a p-n junction between a p-type guard ring and the n<-> drain layer. <IMAGE> |
