| 摘要 |
PROBLEM TO BE SOLVED: To hold down rising of contact resistance by coating at least the bottom of a contact hole which reaches a first conductive layer consisting of cobalt silicide with a second conductive layer which prevents nitriding of the first conductive layer and providing a third conductive layer comprising nitrogen on an upper layer of the second conductive layer. SOLUTION: An inner wall of a contact hole CH which reaches a cobalt silicide layer 12a formed on a heavily doped diffusion layer 12 is coated with a nitriding prevention conductive layer 31 consisting of titanium or tantalum. A barrier metal layer 32 consisting of titanium nitride, for example, is formed on its upper layer. After a plug 33a formed of tungsten is formed to bury a contact hole, an upper layer wiring 34 is formed on its upper layer. Since formation of a high resistance silicon nitride layer is prevented by preventing nitriding of the cobalt silicide layer 12a due to a barrier metal layer 32 comprising nitride such as titanium nitride by the nitriding prevention conductive layer 31, rise of contact resistance can be prevented. |
