SALICIDE PROCESS USING CAPPING LAYER WITH DOUBLE LAYER STRUCTURE

A method for forming a salicide using a capping layer of a duplex structure is provided to prevent the malfunction of a semiconductor device by restricting current leakage such as GIDL in a high voltage gate structure by using a titanium nitride layer as the capping layer. In a salicide process for forming a cobalt silicide using a cobalt coated with a capping layer, a duplex layer which stacks Ti(202) and TiN(203) is used as a capping layer. Wherein, cobalt is coated on a semiconductor substrate in which a gate oxide layer, a gate electrode, source/drain and a spacer are formed. A TiN layer and the Ti are formed on the cobalt. COSi2 is formed by reaction of the cobalt and the silicon through an annealing process. The Ti, TiN layer, silicon and cobalt are eliminated by performing a selective etching process.