| 摘要 |
PURPOSE:To prevent reduction in output of a power supply due to breakdown by using what is obtained by enabling a p-type epitaxial layer on a p-type substrate which is doped in high concentration and by forming a PN junction on the surface. CONSTITUTION:A p-type silicon epitaxial growth film 1-2 with a carrier concentration of 8X10<14>-4X10<16>/cm<2> and a thickness of 1.0-7.1mum is formed on a low-resistance p-type substrate 1-1 made of silicon exceeding a carrier concentration of 1X10<19>/cm<2>. Then, an n<+> type diffusion layer 2 is formed on the surface and a comb-type electrode for collecting current 5 and a rear surface electrode 6 are formed on the surface. Then, a plurality of layers of reflection-prevention films 7 are provided so that they cover the n<+> type diffusion layer 2 and the comb-type electrode for collecting current 5. A region which is sandwiched by dotted lines which are parallel to the epitaxial growth film 1-2 indicates a depletion layer 3, its lower edge 4 descends according to the increase in the inverse bias voltage, and it reaches a low-resistance p-type substrate 1-1 when a certain voltage is exceeded, thus increasing leak current in inverse direction drastically and preventing increase in the inverse bias voltage. |
