| 摘要 |
PURPOSE:To restrain the effect of the overvoltage on the internal elements and raise the breakdown voltage by a method wherein the protective diode is formed into verticaly island type unit independent from the internal elements under the bonding pad electrode. CONSTITUTION:The protective diode 4 forming an N tupe contact layer 112b at the central part thereof is constituted as a vertical type unit with the internal elements 1 connected to the internal wiring 3 after encircling the N type epitaxial layer 103c on the P type substrate 101c with the P type isolated layer 105c to be an independent island unit. Through these procedures, the abnormal overvoltage from the epitaxial source may be reduced by the said protective diode eliminating the unfavorable effect on the internal elements and improving the effect of preventing the breakdown resulting from the surge overvoltage by means of reducing the abnormal field intensity. |
