| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve a negative voltage noise immunity by suppressing local breakdown of an end with respect to negative voltage noise in an insulated-gate type bipolar transistor. SOLUTION: In the insulated-gate type bipolar transistor, a buffer layer 10' for shortening a turn-off time and preventing latch-up is provided, so as not to expose at an end cut face. With such a structure, a breakdown voltage of a p-n junction between a semiconductor substrate 1 and the buffer layer 10' becomes lower than that of a p-n junction between the semiconductor substrate 1 and an n-type layer 2 at the end cut face. Since the breakdown of the entire p-n junction between the semiconductor substrate 1 and the buffer layer 10' causes negative voltage energy to be absorbed through its wide area, its negative voltage immunity can be improved, when compared with that of a prior art having the exposed buffer layer.</p> |
