Fabricating method of a dynamic random access memory

摘要

The present invention provides a fabricating method and structure of a dynamic random access memory. In this method, a substrate having a transistor thereon is provided. A bit line is formed on the substrate. The bit line is electrically coupled with the transistor through a contact hole. A second dielectric layer having a node contact opening is formed on the bit line. An etching step is performed to etch the bit line. A concave surface is formed on the sidewall of the bit line. Spacer layers are formed on the sidewalls of the node contact opening. Each spacer layer is used to insulate the concave surface. Thus, from the top-view layout, a portion of the node contact opening can overlap with the bit line. Thus, the size of DRAM is effectively reduced.