| 摘要 |
PURPOSE:To avoid a leakage current and deterioration of a dielectric strength caused by contamination, light exposure or the like from the outside by a method wherein an anode region of a diode is formed into an annular shape and a base diffused region is provided at the center of the annular region and P-N junction parts on a substrate surface are completely covered with metal electrodes. CONSTITUTION:A P-type collector region 3 and a P-type emitter region 5 are formed on an N-type substrate 4 in which composes a base region to form a P-N-P transistor. A P-type anode region 6 is formed on the substrate 4 annularly and an N-type cathode region 7 is formed on this anode region to form a diode. With this constitution, the P-N junction parts formed on the surface of the substrate 4 can be all covered with metal electrodes. In other words, the junction part between the collector region 3 and the substrate 4 is covered with a collector electrode 9 and the junction part between the substrate 4 and the anode region 6 is covered with an emitter electrode 11 completely. As a result, increase of a leakage current and deterioration of a dielectric strength caused by the exposure of P-N junctions can be avoided. |
