Dynamic random access memory with improved contact arrangements

A semiconductor integrated circuit device and a manufacturing method therefor provide advantages that undulations are prevented from being produced in polycrystal silicon plugs in bit line contact holes and that the undesired phenomenon of transversally etching silicide film at contacts of the bit lines and the polycrystal silicon plugs is avoided. The bit lines formed when forming a first wiring layer are made of a laminate film having a titanium film, a titanium nitride film and a tungsten film, and a titanium silicide film containing nitrogen or oxygen is formed in contact areas of the bit lines and plugs. A titanium silicide film containing nitrogen or oxygen is also formed in contact areas of the first wiring layer and semiconductor substrate. The titanium silicide film may be replaced by silicide film containing nitrogen or oxygen, cobalt silicide film containing nitrogen or oxygen or cobalt silicide film.