A semiconductor substrate having a shallow trench isolation (STI) structure and
a method of manufacturing the same are provided, i.e., an isolation substrate in
which grooves are selectively formed at predetermined locations of the semiconductor
substrate and oxide films using organic silicon source as material are buried in
the grooves as buried oxide films. The present invention is characterized in that
the buried oxide films are annealed at a predetermined temperature within the range
of 1100 to 1350 C. before or after planarization of the semiconductor substrate
such that ring structures of more than 5-fold ring and ring structures of less
than 4-fold ring are formed at predetermined rates in the buried oxide films. The
above annealing allows stress of the oxide film buried in the grooves to be relaxed.
Hence, the generation of dislocation is suppressed.
