| 摘要 |
PURPOSE:To provide a planer structure with higher voltage resistance by covering the surface of semiconductor substrate that is positioned at the middle of electric field limiting rings region with a conductive film through an insulating film, and minimizing the variation of potential distribution in the surface of the semiconductor substrate by use of the electric shielding effect of the conductive film. CONSTITUTION:Field plates 41-44 that are electrically connected with an emitter electrode 40 and electric field limiting rings 32, 34, 36 and 38 extend over electric field limiting rings layer 31, 34, 36 and 38 adjacent to the electric field limiting ring layer and not connected with any part, through insulating films 51-55 and divided into parts above layers 31, 33, 35 and 37. The emitter electrode 40 and the field plates 41-44 are covered with a conductive film that is made of Al mainly. With the shielding effect of the conductive film on the surface of a semiconductor, external factors are shut off. Therefore, when electric charge due to the environment of resin, water, etc., exist, the electric field on a semiconductor substrate is mitigated, the decrease of voltage resistance by local concentration of the electric charge is prevented and higher voltage resistance is provided. |
