| 摘要 |
PURPOSE:To form an electrostatic induction thyristor attaining a small voltage drop, a high maximum forward blocking voltage, and a rapid switching speed by specifying a thickness of a thin layer and its impurity concentration and specifying the maximum forward blocking voltage at that time. CONSTITUTION:An impurity concentration Np2 and a thickness l3 of an N-region 15 are determined so as to satisfy equation (1). The maximum blocking voltage VBamax is expressed by equation (2). This value can not be realized unless a breakdown voltage between a cathode and a gate is high enough to enable sufficient reverse bias of the gate and an enough potential barrier which prevents electron injection from the cathode side can be produced by the gate. Emax can be determined by a relation of a threshold voltage EB at the avalanche start. According to equation (2), for realizing a high blocking voltage with an ultimately thin l2, ND1 gl2/2epsilon should be small enough to be negligible com pared with EB.
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