| 摘要 |
PURPOSE: A method of forming a salicide(self-aligned silicide) layer is to properly suppress diffusion of cobalt when forming the salicide layer, thereby providing high thermal stability and low sheet resistance. CONSTITUTION: The method comprises the steps of: forming a polysilicon layer on a semiconductor substrate(31) and selectively patterning it to form a gate electrode(34); forming a gate side wall on a side of the gate electrode; implanting impurity ions into a surface of the semiconductor substrate at both sides of the gate electrode to form a source/drain region(36); forming a cobalt thin film on a whole surface including the gate electrode; performing the first annealing process to form a CoSi thin film(monosilicide)(38) at an interface of the cobalt thin film adjoining the semiconductor substrate and a surface of the gate electrode by diffusion of silicon; removing the cobalt thin film remaining unreacted with silicon and implanting N2 ions by a depth above a thickness of the CoSi thin film; and diffusing cobalt using the second annealing process to form a CoSi2 thin film.
|
