Fabrication method of trench type device isolation structure and trench type device isolation

摘要

The present invention provides a method for producing a trench type device isolation structure in which recesses do not occur at the edge portions of the buried oxide film of trench type device isolation.;The thermal oxide film having higher etching resistance than the CVD film is formed not only around the buried oxide film inside the groove formed in the silicon substrate but also on the side surface of the buried oxide film protruding upward from the silicon substrate surface.