| 摘要 |
PURPOSE:To improve the switching characteristic of a high voltage resistance planar-type semiconductor device, by providing two high-concentration layers opposite to the P-N junction of a planar structure having curvature, and by regulating the set positions of these high-concentration layers. CONSTITUTION:A P-type base region 12 and a guard ring layer 13 are formed on the main surface side of a semiconductor substrate 11 operating as an N-type high-resistance layer. On the back surface side of the substrate 11, on the other hand, a first high-concentration layer 18 of an N<+> type is formed so that it is opposite to the region 12. Moreover, a second high-concentration layer 19 of an N<+> type is formed on the back surface side of the substrate 11 so that it surrounds the layer 18. On the occasion, the width H1 of the layer 18 and the opposition width H2 of the layer 19, and the width W of the region 12 and the width I0 of a high-resistance layer 22 between the region 12 and the region 18, are set so that the relationship W+2I0>H2>H1 is established among them. According to this constitution, the set position of the layer 19 can be put apart from a high electric field region inside the layer 22 in relation to the curvature portion of the P-N junction, and thus the switching characteristic can be improved. |
