| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for forming an embedded contact band which has simple production steps, the embedded contact band and a DRAM formed by this method. SOLUTION: In the method, a trench is formed on a semiconductor substrate, a first conductive layer is partially charged inside the trench, and an annular insulating layer is formed on the inner wall of the upper part of a deep trench which is located higher than the first conductive layer; than a second conductive layer is formed on the first conductive layer so that the surface of the second conductive layer can be set lower than the surface of the substrate, the surface of the annular insulating layer is lowered rather than the surface of the second conducting layer, and the annular insulating layer is partially removed, so that one part of the inner wall of the trench is re-exposed; and then a third conductive layer which set as the embedded contact band is formed on the exposed part of the inner wall of the trench and the surface of the second conductive layer by a selective growth method.
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