| 摘要 |
PURPOSE:To thoroughly reduce the minimum trigger quantity of light by a mechanism wherein life-time killer atoms are prevented from being contained in a semiconductor layer located below a light receiving surface forming a photo-trigger thyrister, and the life-time of the layer is kept larger than those of others. CONSTITUTION:A P type emitter layer 2 is formed on the reverse side of an N type base 1 and a P type base layer 3 on the surface thereof; a ring and a similar ring- shaped N type emitter region 4 surrounding the ring are provided in the layer 3; an anode electrode 5 is formed on the reverse side of the layer 2, and a similar ring- shaped cathode electrode 6 on an annular region 4 to incide lights 7 on this side. With this construction, width R of the internal region 4 is enough to widen for reducing the minimum trigger quantity of light, while du/dt withstand value becoming small, and diffusion of Au for shortening the turn-on period of time increases the quantity of light required. Therefore, the life-time only is kept long without diffusing Au onthe semiconductor layer under the light receiving surface. |
