| 摘要 |
PURPOSE:To eliminate a short circuit between a cathode and a gate in a semiconductor device having a mesa type surface structure by not forming a gate electrode at the center of a mesa groove. CONSTITUTION:In a power semiconductor device having a GTO, a gate electrode is composed of the first and second gate electrode 14, 15 disposed only at both side edges of a mesa type groove. Thus, since the thickness of an insulator 7 at the center of the groove becomes very thicker than that of the insulator 7, the relative insulating withstand strength at the center of the groove largely increases. Accordingly, even if the thickness of the insulator 7 in the groove is irregular, no insulation breakdown might occur, and even if a projection formed at a thermal buffer plate 10 is intruded into the layer of the insulator 7 at the center of the groove, the gate electrode is not present on most of the groove. Therefore, a short circuit may not occur between a cathode electrode 8 and the gate electrodes 14, 15. |
