| 摘要 |
PURPOSE: A method for manufacturing a DRAM device is provided to improve the reliability of a metal wiring by reducing a step difference between a cell region and a peripheral circuit region. CONSTITUTION: A method for manufacturing a DRAM device comprises the following steps. A capacitor(4) is formed on a cell region of a semiconductor substrate. The second and the third insulating interlayers(5,6) are deposited on the cell region and a peripheral circuit region. The first contact hole(7) is formed by etching the third, the second and the first insulating interlayers(6,5,2) of the peripheral region. A tungsten layer(8) is deposited on the third insulating interlayer(6). A sacrificial oxide layer is deposited on the tungsten layer(8). The sacrificial layer remains on the peripheral circuit region by polishing the sacrificial oxide layer. The tungsten layer(8) remains the peripheral circuit region by polishing the tungsten layer(8) and the sacrificial oxide layer. The second contact hole is formed by etching the exposed insulating interlayer(6) of the cell region. An aluminium layer(10) is deposited on the insulating interlayer(6) of the cell region and the tungsten layer of the peripheral circuit region. A metal wiring of a single structure is formed on the cell region and a metal layer of a lamination structure is formed on the peripheral circuit region by etching the aluminium layer and the tungsten layer.
|
