The method includes the following procedures. The source/drain electrode ion implantation is carried out on the substrate with the grid electrode and the gap wall of the side wall being formed so as to form the source/drain electrode area in the substrate on the side of the gap wall. The self-aligned metallic silicide layer is formed on the surface of the source/drain electrode. Then, the part ofthe gap wall is removed in order to form the gap wall with the section being as triangle. The slant pocket ion implantation is carried out to form the pocket adulteration area in the substrate near the grid electrode. Moreover, the location and the distribution of the adulteration area are controlled. The extended area of the source/drain electrode is formed. Finally, the jointing depth and the adulteration contour of the extended area of the source/drain electrode are adjusted by the thermal cycle techniques.