| 摘要 |
PURPOSE:To improve the yield by providing the steps of opening the second window which exposes a substrate region corresponding to a nitrided film, introducing reverse conductive type impurity into the substrate through the second window to form a base region and a guard ring layer, thereby reducing the number of photoetching steps. CONSTITUTION:Windows (by first etching) 56 for forming a guard ring layer, a P<+> type guard ring layer, a P<+> type contacting region and a base region are opened at an epitaxially grown layer 51. Windows (by second etching) 59 are opened for forming a guard ring layer and a P<+> type contacting region at a nitrided silicon film 58. the film 58, a polycrystalline silicon layer 54 and an oxidized film 61 are removed to expose the present voltage ring surface 65 of the layer 51 (by third etching). Contacting holes 69a,...,69d are opened by a photoetching method (by fourth etching). An electrode layer is patterned by a photoetching method to form a pickup electrode 70 (by fifth etching). A window for producing a bonding pad is opened (by sixth etching) to obtain a semiconductor device. |
