| 摘要 |
A method for fabricating a semiconductor memory device is provided. The method includes: forming a trench in a portion of a substrate, defined as a cell region; forming a first polysilicon layer doped with N-type impurities on regions where N-type metal-oxide-semiconductor (MOS) transistors are to be formed in the cell region and the periphery region; forming a second polysilicon layer doped with P-type impurities on an area where a P-type MOS transistor is to be formed; forming a gate metal layer over the first and the second polysilicon layers; forming a gate hard mask layer on the gate metal layer; and patterning the gate hard mask layer, the gate metal layer, and the first and the second polysilicon layers to form gate patterns for the N-type MOS transistors in the cell region and the periphery region, and the P-type MOS transistor in the periphery region. |
