| 摘要 |
PURPOSE:To obtain a GTO wherein a reduced conductive region is widened and controllable anode current is increased, by constituting n type emitter regions of high impurity concentration regions formed close to peripheral gate electrodes and of low impurity concentration regions whereon the regions contact at least a pair of opposed sides. CONSTITUTION:A second low impurity concentration region 42 constituting the center of an n type emitter region 4 is surrounded by a first high impurity concentration region 41 constituting the periphery close to the gate electrode 7 of the n type emitter region 4. It is desired that the surface impurity concentrations of the regions 41 and 42 for the surface impurity concentration of the p type base region are respectively at 100 times or more and at 1-100 times. A GTO which the region 42 of the n type emitter region 4, the p type base region 3, an n type base region 1 and an p type emitter region 2 constitute is an A-GTO, and the GTO which the region 41 of the n type emitter region 4, the p type base region 3, the n type base region 1 and the p type emitter region 2 form is a B-GTO. When the turn-off of this GTO, the A-GTO reaches the conditions alpha1+alpha2<1 ahead of the B-GTO, and accordingly first the A-GTO becomes a stopping region resulting in the reduction of a conductive region on the boundary region between the A-GTO and the B-GTO. |
