US Patent 7195977 Method for fabricating a semiconductor device

A method for fabricating the semiconductor device includes forming linear field oxide regions on a semiconductor substrate; forming gate oxide lines on the semiconductor substrate between the field oxide regions; forming gate lines on the field oxide regions and the gate oxide lines, the gate lines being substantially perpendicular to the field oxide regions; etching the gate oxide lines and the field oxide regions between the gate lines; and forming a self-aligned source (SAS) region by injecting impurity ions into the etched regions, the impurity ion being injected in a direction at a predetermined angle other than 90° relative to the semiconductor substrate.