Abstract: 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.

Abstract: 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.degree. 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.

Abstract: According to the present invention, to flatten the surface of a silicon substrate by polishing an element isolating buried insulation film by chemical mechanical polishing, a polysilicon film is formed on the top surface of a projection of a silicon substrate. After that, a buried insulation film is formed all over the silicon substrate along the irregularities thereof. A carbon film is formed on the surface of a recess of the buried insulation film. Using the carbon film as a stopper, the buried insulation film is polished by the chemical mechanical polishing to ease the irregularities of the surface of the polished insulation film. Then the carbon film is removed and, using the polysilicon film as a stopper, the buried insulation film is polished by the chemical mechanical polishing to flatten the surface of the polished insulation film. Thus, the flatness of the buried insulation film can easily be controlled, and the surface of the silicon substrate can always be flattened satisfactorily.