A method of fabricating a cobalt silicide layer includes providing a substrate disposed in a chamber. A deposition process is performed to form a cobalt layer covering the substrate. The deposition process is performed when the temperature of the substrate is between 50° C. and 100° C., and the temperature of the chamber is between 300° C. and 350° C. After the deposition process, an annealing process is performed to transform the cobalt layer into a cobalt silicide layer. The annealing process is performed when the substrate is between 300° C. and 350° C., and the duration of the annealing process is between 50 seconds and 60 seconds.