Method of manufacturing semiconductor device

摘要

An object is to obtain a method of manufacturing semiconductor devices having trench isolation structure which accomplishes simplification of manufacturing process without deterioration of polishing uniformity. After a silicon oxide film (5) is deposited an HDP-CVD method, a polysilicon film (6) is deposited to such a thickness that the polysilicon film (6) on upper regions of raised areas is removed and the polysilicon film (6) in recessed areas remains in a first CMP process and that the polysilicon film (6) serves as a mask in a later etching process. Subsequently, the first CMP process is performed and the etching process to the silicon oxide film (5) is performed by using the polysilicon film (6) after the first CMP process as a mask to remove the silicon oxide film (5) in the upper regions of the raised areas, and a second CMP process is further performed to planarize the semiconductor substrate (1).