| 摘要 |
PURPOSE:To prevent surface avalanche breakdown and obtain stable high dielectric strength characteristics by removing the punch-through along the side end faces of an SCR, triac, etc. having pulley shape. CONSTITUTION:A pair of approximately parallel main surfaces are formed to a semiconductor substrate 100 and side end faces 8 are so formed as to connect main surfaces. An n layer 1 of n type, second p layers 2, 3 of P type by a specific resistance higher than that of the n layer 1 ajoining to this n layer 1 are formed between a pair of main surfaces. Further, a third n layer 4 of n type of a specific resistance lower than that of the P layer 2 is formed in adjacency to the second P layer 2. And the side end faces 8 connecting the main surfaces with each other are so formed that the through part 81 is positioned in the approximate central part of the second P layers 2, 3 and the faces from the through part 81 to both main surfaces are formed to such a shape that the sectional area approximately parallel with the main surfaces inceases as it approaches to both main surface. The side end faces 8 of the substrate 100 are covered with an insulator 9. And it is so formed that the charges of the same code as charge carriers to determine one of conductivity types are induced in the side end faces 8 by the insulator 9. |
