A method of forming a metal layer on the conductive region of a semiconductor device includes concurrently supplying a mixture gas including a hydrogen gas and a metal chloride compound gas, and a purge gas into a chamber having a sealed space for a predetermined time, thereby forming a first metal layer on the semiconductor substrate, using a plasma enhanced chemical vapor deposition (PECVD) method. The hydrogen gas and metal chloride gases are thereafter alternately supplied for a predetermined time while the purge gas is continuously supplied into the chamber, thereby forming a second metal layer on the first metal layer, using a PECVD method. Deterioration of semiconductor devices due to high heat by a conventional CVD method can be prevented using a PECVD method as a low temperature process, thereby improving a production yield.