| 摘要 |
A method of forming a contact for a dynamic random access memory device is disclosed. In this method, a first insulating layer is formed on a semiconductor substrate. First and second contact pads are formed in the first insulating layer and on a semiconductor substrate in such a manner that a top surface of the first insulating layer is higher than top surfaces of the contact pads. Then a second insulating layer is formed over the substrate, which layer shows a bad step coverage. The second insulating layer is etched until the surfaces of the first and second contact pads are exposed. Then a first conductive layer is formed over the entire surface of the semiconductor substrate, and the first conductive layer is flattened, leaving some thickness of the second insulating layer. Then a second conductive layer is formed over the first conductive layer, and the second and first conductive layers are sequentially etched using a bit line forming mask, to form a bit line. Under this condition, the first conductive layer on the first contact pad is over-etched to form an electrical insulation from the bit line. When forming the direct contacts of a cell region and a core region, the photo process for forming the DC of the cell region or the BC and DC of the cell region, and the photo process for forming the DC of the core region can be skipped to simplify the formation process, thereby saving manufacturing costs.
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