| 摘要 |
PURPOSE:To improve the working efficiency by using a silicon nitride film having excellent etching resistance property as an etching mask to reduce the film reduction at groove forming time, and to epitaxially grow selectively in case of burying the groove with the epitaxial layer, thereby reducing the following polishing amount of flattening the surface. CONSTITUTION:The surface of a P-type silicon substrate 11 is thermally oxidized, an SiO2 film 12 is formed, and the upper surface and the sides of the film 12 are then coated with an SiN film 14. Then, with the film 14 as a mask the substrate 11 is selectively etched to form a recess 15 of the prescribed depth. Subsequently, with the same film 14 as a mask a phosphorus is selectively diffused, and an N<+> type impurity region 16 is formed on the wall of the groove 15. Then, with the films 14, 12 retained an epitaxial growth is executed and a single crystal layer 17 is grown selectively only on the surface of the groove 15 exposed with the substrate to bury the groove. Thereafter, the surface of the wafer is polished by both-side polishers to remove the films 14, 12.
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