| 摘要 |
PURPOSE: A method for manufacturing a semiconductor device is provided to restrain a punch-through and to improve a refresh characteristic by forming an LDD(Lightly Doped Drain) region after activating source and drain regions. CONSTITUTION: Gate electrodes comprising a gate oxide and a doped polysilicon layer(13), a tungsten silicide(14) and a cap oxide(15) are formed on a semiconductor substrate(11) having a cell and a peripheral region. After forming a spacer at both sidewalls of the gate electrodes of the peripheral region, source and drain regions(19) are formed by implanting heavily doped dopants and by activating using a first annealing. Then, a first LDD region(21) is formed in the cell region. A second LDD region(22) is formed in the peripheral region by implanting lightly doped dopants and by a second annealing.
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