METHOD FOR MANUFACTURING TUNGSTEN GATE ELECTRODE OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for manufacturing a tungsten gate electrode of a semiconductor device is provided to improve a gate oxide integrity(GOI) characteristic and to stably maintain a resistivity characteristic of a gate electrode, by minimizing reaction between tungsten and doped polysilicon so that ion diffusion to a polysilicon layer and a gate insulation layer is prevented while silicide reaction on an interface between tungsten and polysilicon is controlled. CONSTITUTION: A gate insulation layer and a doped polysilicon layer are sequentially formed on a semiconductor substrate(10). A plasma treatment is performed in a nitrogen gas atmosphere regarding the upper portion of the doped polysilicon layer to form a silicon nitride thin film on the doped polysilicon layer. A tungsten layer is deposited on the silicon nitride thin film. The tungsten layer, the silicon nitride thin film and the doped polysilicon layer are patterned to form a gate electrode(G) of a semiconductor device. A thermal oxidation process is performed regarding the resultant structure having the gate electrode to a lightly-doped-drain(LDD) screen oxide layer(22) while the silicon nitride layer inside the gate electrode is transformed to form a barrier metal layer.