Patent ID: 7629223

Claim:
A method for manufacturing a semiconductor device, the semiconductor device to be manufactured having a plurality of semiconductor elements in an active region defined on a semiconductor substrate, said method comprising: a first step of forming a plurality of element isolation trenches and a plurality of alignment mark trenches on the substrate, and laminating an oxide film on the substrate and over the element isolation trenches and the alignment mark trenches; a second step of etching the oxide film using a resist mask, which masks the element isolation trenches, so as to remove the oxide film laminated in the active region and the oxide film laminated in the alignment mark trenches; a third step of planarizing or smoothing a surface of the substrate by polishing such that those portions of the oxide film which project from the surface of the substrate are eliminated and the oxide film remains only inside the element isolation trenches, whereby the active region is divided into a plurality of individual active regions for the respective semiconductor elements; a fourth step of positioning the resist mask using the alignment mark trenches, said resist mask being used when providing the semiconductor elements; and a fifth step of providing the semiconductor elements in the plurality of individual active regions.