Method of forming gate electrode in semiconductor device

Abstract

A method of forming a gate electrode in semiconductor device which can prevent transformation of the gate electrode, is disclosed. According to the present invention, a gate insulating layer, a doped polysilicon layer and a sacrificial layer are formed on a semiconductor substrate, sequentially. The sacrificial layer and the polysilicon layer are then etched in the shape of a gate electrode to form a sacrificial pattern and a polysilicon pattern. Next, the substrate is re-oxidized to form a re-oxidation layer on the side walls of the polysilicon pattern and LDD ions are implanted into the substrate of both sides of the re-oxidation layer. A spacer of an insulating layer is then formed on the side walls of the sacrificial pattern and the re-oxidation layer and impurity ions of a high concentration are implanted into the substrate of both sides of the spacer. Thereafter, an intermediate insulating layer is formed on the overall substrate and etched to expose the surface of the sacrificial pattern. The exposed sacrificial pattern is then removed to form a trench and a barrier metal layer is formed on the surface of the trench. Next, a refractory metal layer is formed so as to fill the trench on which the barrier metal layer is formed, to form a gate electrode having the polysilicon pattern, the barrier metal layer and the refractory metal. Furthermore, the sacrificial layer is formed to the thickness of 500 to 1,500 Å using a silicon nitride layer. The sacrificial pattern is selectively removed by wet etching using H3PO4.

Dependencies are inferred from the claim text.