| 摘要 |
PURPOSE:To form an element isolation region, which can be flattened and miniaturized by simple steps, by digging the bottom part of a groove, and embedding a single crystal silicon layer in the groove by using a selective epitaxial method in the fourth step. CONSTITUTION:Ions of specified impurity species such as As<+>, B<+>, P<+> and the like are implanted in a groove 4, in which a thermal oxide film 5 is formed, and a channel cutting layer 6 is formed. Only the thermal oxide film 5 at the bottom part of the groove 4 undergoes anisotropic etching by an RIE method in a mixed gas atmosphere. The bottom part of the groove 4 is further etched. The bottom part of the groove 4 is further dug as shown by a numeral 8. Thereafter, a single crystal silicon layer 9 is embedded in the groove 4 by a selective epitaxial method. Finally, the surface is oxidized, and a flat oxide film 10 is formed on the surface of the single crystal silicon layer 9 in the groove 4. Since the oxide films 5 and 10 are insulating films and the channel cutting layer 6 is also an insulating region in this constitution, an element isolation region including the single crystal silicon layer 9 in the groove 4 is formed.
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