Patent attributes
Disclosed herein is a method of manufacturing a semiconductor device having a step gate, which can improve the refresh characteristics of the device. The method comprises the steps of: forming on a silicon substrate having active and field regions a first hard mask exposing the field region; etching the exposed field region to form a trench; forming an isolation film by filling an insulating film in the trench; forming a second hard mask exposing both sides of the active region by etching the first hard mask; forming a metal film on the resulting substrate including the second hard mask; forming a metal silicide film on both sides of the active region by annealing the resulting substrate; removing the metal film unreacted in the annealing step and the metal silicide film, thereby recessing both sides of the active region; removing the second hard mask; and forming a step gate on both edges of the central portion of the active region and the recessed portion of the active region, adjacent to each of the edges.
