| 摘要 |
PURPOSE:To make the switching to be performed by an optical trigger signal having approximately constant magnitude at all times at a high ignition sensitivity, by reducing the thickness of the part of the intermediate layer close to the side of the irradiation of the optical trigger signal, corresponding to the optical trigger signal irradiating point, so that it is made thinner than the other part. CONSTITUTION:A numeral 1 is a semiconductor substrate having four continued layers of nE, PE, nB, and pE between a pair of main surfaces 11 and 12, which are located on opposing sides. A numeral 2 is a cathode electrode which is contacted with the part of the exposed surface of the nE layer other than the central part and the exposed surface of the PB layer at a low resistance. A numeral 3 is an anode electrode which is contacted with the exposed surface of the pE layer in the other main surface 12 at a low resistance. A numeral 5 is a channel region, which is formed by piercing the pB layer by a part of the nB layer and protruding it until it reaches the nE layer, at the position corresponding to the optical trigger signal irradiated point at one main surface 11. When the optical trigger signal is irradiated on the exposed surface of the nE layer by a means 4, the light is inputted into the channel region 5 through the nE layer. Then the PEnBnE diode region becomes low impedance state, a diode current flows, and the PEnBPBnE four layer regions at the peripheral patt of the channel region 5 is turned ON. |
