| 摘要 |
PURPOSE:To form the width of the region determining a punch through voltage with high accuracy by using a P-N junction structure in which a direction of punch through is lateral. CONSTITUTION:An N type semiconductor layer 12 is formed on an N<+> type semiconductor substrate 11 and P type semiconductor regions 13 and 14 are formed adjacently to said semiconductor layer 12 laterally. The semiconductor regions 14, 14 formed on both sides of the semiconductor region 13 are shortened by a shortage electrode 15 and an anode electrode 16 and a cathode electrode are formed in the region 13 and on a back surface of the substrate 11 respectively. In the constant-voltage diode thus constituted, when a voltage is applied between the anode electrode 16 and cathode electrode 17 and is enhanced, the break-down occurs for a PNP junction among the P type regions 14, N type region 12 and the P type region 13 in lateral direction. Accordingly, the width of the region which determines a punch through voltage can be formed easily with high accuracy. |
