A semiconductor integrated circuit device and a method of manufacturing such a device provides the advantages that undulations are prevented from being produced in the polycrystal silicon plugs in the bit line contact holes and that the undesired phenomenon of transversally etching the silicide film at the contacts of the bit lines and the polycrystal silicon plugs is avoided. The bit lines BL formed at the time of forming a first wiring layer 18 is made of a laminate film having a titanium film 18a, a titanium nitride film 18b and a tungsten film 18c and a titanium silicide film 20 containing nitrogen or oxygen is formed in the contact areas of the bit lines BL and the plugs 19. A titanium silicide film 20 containing nitrogen or oxygen is also formed in the contact areas of the first wiring layer 18 and the semiconductor substrate 1. The titanium silicide film 20 may be replaced by a tungsten silicide film containing nitrogen or oxygen, a cobalt silicide film containing nitrogen or oxygen or a cobalt silicide film.