A method for manufacturing a semiconductor memory device is provided to prevent the damage of a semiconductor substrate by performing a patterning process for forming a blocking layer after performing an ion implantation process. A tunnel dielectric layer(102), a charge storing layer(104), a blocking dielectric layer(106), and a gate electrode(108) are formed on a semiconductor substrate(100). A first etching process is performed to remove an edge of the blocking dielectric layer. An ion implantation process is performed on the semiconductor substrate. A high-k dielectric layer is formed on an upper portion of the entire structure including a part of which blocking dielectric is removed. A second etching process is performed so that the high-k dielectric layer remains only between the gate pattern and the charge storing layer. The blocking dielectric is formed with one of LPTEOS(Low Pressure Tetra-Ethyl-Ortho-Silicate), HTO(High Temperature Oxide), PE-USG(Undoped Silicate Glass), or an oxide nitride layer. A thickness of the blocking dielectric layer is 50 to 1000 Å.