| 摘要 |
<p>An insulated gate bipolar transistor having a gate electrode (7) and an emitter electrode (9) is provided in a transistor region. A termination region is arranged around the transistor region. A first N type buffer layer (18) is provided below an N type drift layer (1) in the transistor region. A P type collector layer (19) is provided below the first N type buffer layer (18). A second N type buffer layer (20) is provided below the N type drift layer (1) in the termination region. A collector electrode (21) is directly connected to the P type collector layer (19) and the second N type buffer layer (20). An impurity concentration of the second N type buffer layer (20) decreases as a distance from the collector electrode (21) decreases. The second N type buffer layer (20) does not form any ohmic contact with the collector electrode (21).</p> |
