Thyristor with a self-protection function for breakover turn-on-failure

摘要

A thyristor is comprised of a main thyristor region (21), a gate region (22) for causing the main thyristor region to be turned on in response to a gate signal, and an amplifying gate region (34) which is turned on to permit the main thyristor region to be turned on when an overvoltage is supplied to the thyristor in the absence of gate signal at the gate portion. The amplifying gate region is provided in a region except an intermediate region between the gate portion and the end (37) of the main thyristor region facing the gate portion. A minority carrier lifetime in the amplifying gate region is longer than that of the main thyristor region and the gate portion.