Method of fabricating shallow trench isolation structure

摘要

A method of fabricating a shallow trench isolation structure is described. A mask layer is formed on the substrate. The mask layer and the substrate are patterned to form trenches in the substrate. The trenches comprise a smallest trench. A first isolation layer is formed on the mask layer to fill partially the trenches. A densification step is performed. A second isolation layer is formed on the first isolation layer to fill completely the trench. The first isolation layer and the second isolation layer are removed until the mask layer is exposed. The mask layer is removed.