Example embodiments relate to a method of forming a germanium (Ge) silicide layer, a semiconductor device including the Ge silicide layer, and a method of manufacturing the semiconductor device. A method of forming a Ge silicide layer according to example embodiments may include forming a metal layer including vanadium (V) on a silicon germanium (SiGe) layer. The metal layer may have a multiple-layer structure and may further include at least one of platinum (Pt) and nickel (Ni). The metal layer may be annealed to form the germanium silicide layer. The annealing may be performed using a laser spike annealing (LSA) method.