| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the switching loss of an insulated-gate bipolar transistor due to excessive minority carriers at the switching-off time of the transistor by a method wherein a first gate is formed on the surfaces of a first conductivity type well and a semiconductor layer and a second gate is formed on one part of a second emitter region, the semiconductor layer and on the surface of the first conductivity type well between the second emitter region and the semiconductor layer. SOLUTION: In the structure, wherein a p<+> diffused region 48 is formed in n-type and n<+> emitter regions 44 and 46, of an insulated-gate bipolar transistor, electrodes are moved round the region 48 and are made to flow through an N-channel, which is formed in an external p-type well 40, in the switching-off state of the transistor. Moreover, at the switching-off time of the transistor, holes in an epitaxial layer 30 are extracted in an emitter terminal through a P-channel, which is formed in the region 44 in the regions 44 and 46. As the holes are made to flow through the channel, plenty of the holes are extracted during a short time to reduce the switching time of the transistor.</p> |
