| 摘要 |
PURPOSE:To obtain a shorted emitter construction by lowering the resistance of the emitter shorted portion where the base layer penetrates the emitter layer, thereby mitigating the increase in the ion voltage. CONSTITUTION:Impurity concentration on the surface of emitter shorted portions 5a is set to more than 10<-9>/cm<3>. Also the diameter D of the emitter shorted portion is set to less than 30 mum, and the interval between emitter shorted portions is arranged to be less than 200 mum. Consequently, the ratio of the area occupied by the shorted emitter to the cathode area is reduced, and the ON-voltage will be lowered by about 5%. Further, expansion of the conductive region at the time of turning-ON will become more uniform than that of SCR of the conventional consturction, and expanding rate will be increased by 0.05 mm/mus to 0.08 mm/mus compared with the conventional device. Since the impurity is diffused at high concentration only to the shorted emitter region, no adverse effects will be observed upon the gate characteristic of SCR, and various other characteristicsof OFF-voltage, OFF-current, holding current and latch current. |
