Semiconductor device and manufacturing method thereof

摘要

A semiconductor device has a semiconductor substrate, an element isolation insulation film embedded in a trench formed in said semiconductor substrate in a state of protruding from a surface of said semiconductor substrate and a transistor having a gate electrode provided in an area surrounded by said element isolation insulation film on said semiconductor substrate, and containing a gate electrode deposited through a gate insulation film before embedding said element isolation insulation film and an upper edge corner of said element isolation insulation film is selectively recessed. In the thus structured semiconductor device, the upper edge corner of the element isolation insulation film is recessed before the patterning process of the gate electrode, thereby preventing such a situation that a part of the gate electrode remains unetched in the patterning process of the gate electrode.