| 摘要 |
PURPOSE:To obtain a thyristor to be used for large electric power and to operate at a high speed by a method wherein the gate region to constitute the electrostatic induction type thyristor is constituted with the two frustum of pyramid type regions, and the reverse conductive type region occupying the position between them is used as the channel region. CONSTITUTION:An oxide film 9 is adhered on an N<-> type semiconductor substrate 4 occupying the position between a gate and a cathode of the electrostatic induction type thyristor, anisotropic etching is performed enlarging size of openings to be provided in a film 13 in order changing the shape of pattern of the photo resist film13 to be provided thereon, and the reverse frustum of pyramid type concave parts are formed in the substrate 4. Then the films 9, 13 are removed, the P<+> type regions 3 to form the gate are buried in the concave parts by epitaxial growth, the upper parts thereof are covered with N type layers 14, an N<-> type layer 2 is made to grow epitaxially on the whole surface suppressing jumping out of impurities from the regions 3, and the part of the layer 2 between the regions 3 is used as a channel 8. After then, the substrate is turned upside down, an N type layer 10 and a P type layer 1 to form an anode are made to gorw being laminated on the layer 2, and the N<+> type region 11 is formed by diffusion in the layer 1. |
