| 摘要 |
PURPOSE:To prevent the dielectric breakdown from taking place adjacently to a ring electrode by a method wherein a high-voltage resistant transistor is provided, where an inner edge of a ring-like electrode is arranged nearer to a base electrode than an inner edge of a ring-like diffusion layer. CONSTITUTION:An inner edge 151 of a ring-electrode 15 is arranged nearer to a base electrode 14 of a high-voltage resistant resistor than an inner edge 131 of an N-type diffusion layer 13. That is, provided that distances between an outer edge 141 of the base electrode 14 and the inner edge 151 of the ring electrode 15 or the inner edge 131 of the N-type diffusion layer 13 are represented by X1 and X2 respectively, X1 and X2 are so set as to satisfy the inequality X1< X2. In the structure of the ring electrode 15 covering the N-type diffusion layer 13, the part E of a semi-insulating film 16 overlapping with the N-type diffusion layer 13 is kept everywhere at the same potential as the N-type diffusion layer 13. Therefore, even though a depletion layer 18 does not exist, an electric field is hardly applied onto a semi-insulating film 17 at the part E, so that a dielectric breakdown is prevented from taking place at the part E. |
