| 摘要 |
<p>An insulated gate bipolar transistor comprises a first layer (1) of semiconductor material of one conductivity type, an emitter electrode (6) on said first layer, a second layer (2) of semiconductor material of the opposite conductivity type adjoining said first layer, a continuous buffer layer (9) between said first and second layers of the same conductivity type material as said second layer, but of higher impurity concentration, a third layer (3) of semiconductor material of said one conductivity type overlying part of said second layer, a fourth layer (4) of semiconductor material of said opposite conductivity type overlying part of said third layer, a collector electrode (5) connected over an exposed junction between said third and fourth layers and locally shorting said third and fourth layers together, a gate electrode (8) overlying the surface of said third layer between the second and fourth layers, but insulated therefrom, a base contact region (12) overlying a portion of the second layer at a position spaced from the third layer and formed of the same conductivity type material and during the same process step as the fourth layer, a base contact electrode (11) on said base contact region and an external electrical connection (10) between said base contact electrode and the emitter electrode. <IMAGE></p> |
