| 摘要 |
PURPOSE:To make it possible to implement miniaturization and high density integration of cells and to prevent a punch through phenomenon effectively, by forming a reverse conductivity type third semiconductor layer at impurity concentration lower than that of a first semiconductor layer more deeply. CONSTITUTION:In an epitaxial layer 2, reverse conductivity type impurities are doped at a low concentration at a position, which is partially over-lapped with a part of a polycrystalline silicon pattern 6 through a first insulating film 5a, and a p-type semiconductor layer (first semiconductor layer) 4 is provided at a shallow depth. In an opening part in the polycrystalline silicon film pattern 6, a p<-> type semiconductor layer (third semiconductor layer) 11, whose impurity concentration is lower than that of the p-type first semiconductor layer 4, is formed along the edge of said pattern with uniform interval being kept at a deep place than the p-type semiconductor layer 4. On the surface of the p-type first semiconductor layer 4, an n<+> type semiconductor layer (second semiconductor layer) 8 is formed at a position, which is partially over lapped with a part of the conductor film pattern 6, through the first insulating film 5a. An insulating oxide film (second insulating film) 5d is formed so as to coat the polycrystalline silicon film pattern 6. A source Al electrode film (metal electrode film) 9 is formed on the insulating film. |
