METHOD FOR FABRICATING SHALLOW TRENCH ISOLATION STRUCTURE

摘要

PROBLEM TO BE SOLVED: To provide a method for fabricating a shallow trench isolation structure, by which the formation of a recess at the upper corner portion of the shallow trench isolation structure can be effectively prevented by protecting the upper corner portion of the shallow trench isolation structure. SOLUTION: A pad oxide layer and a mask layer are continuously formed on a substrate. A trench is formed by patterning a portion of the pad oxide layer and the mask layer. A liner layer is formed on the exposed face of the substrate including a silicon surface exposed in the trench of the substrate, on the sidewall of the pad oxide layer, and on the sidewall and the surface of the mask layer. A planarization process is carried out until the mask layer is exposed after the trench is filled with oxide layer by depositing over the trench and the substrate. The shallow trench isolation structure is completed by removing the mask layer and the pad oxide layer.