| 摘要 |
PURPOSE:To eliminate the deterioration of element characteristics such as high dielectric strength completely and obtain a more reliable element by covering the surrounding structure of a cell integrating part with an undoped semiconductor film. CONSTITUTION:A field silicon oxide film 5b is formed over field limiting rings (P<+> type semiconductor layers 3c and 3d) and, after undoped polycrystalline silicon 6a is deposited, selectively patterned. The polycrystalline silicon 6a is applied so as to cover the gate electrode part and a P<+> type semiconductor layer 3b and then cover the field limiting ring of the P<+> type semiconductor layer 3c and reach the tip part of the semiconductor chip. The polycrystalline silicon above the field limiting rings and a region for a gate protecting diode is selectively covered with a photoresist and, after a source N<+> type semiconductor layer 8 and an N<+> type polycrystalline silicon layer 6c are formed by ion implantation, an undoped CVD-SiO2 film 5d and a PSC film 5e which contains high concentration phosphorus are formed. |
