METHOD FOR MANUFACTURING OF SEMICONDUCTOR DEVICE

摘要

A method for fabricating a semiconductor device is provided to maintain a uniform CD of a second hard mask by preventing the profile of the second hard mask from being varied in an etch process for forming a recessed gate electrode. A semiconductor substrate(110) having an isolation layer(111) is prepared. A first hard mask(113) having high etch selectivity with respect to the isolation layer is deposited on the substrate including the isolation layer. A second hard mask(114) having high etch selectivity with respect to the substrate is deposited on the first hard mask. The second and the first hard mask are etched to form first and second hard mask pattern. The substrate is etched by using the second hard mask pattern to form a trench in the substrate. The second and the first hard mask pattern are eliminated. A gate electrode is filled in the trench. The first hard mask is made of a material having higher etch selectivity with respect to the isolation layer as compared with the second hard mask.