Method of manufacturing a gate electrode in a semiconductor device

Abstract

The present invention relates to a method for manufacturing a semiconductor device having a gate electrode (e.g. tungsten gate electrode) of low resistivity. In the method for manufacturing a semiconductor device, a conductive sacrifice polysilicon pattern is formed on a gate insulating film and then a first interlayer insulating film is deposited. The first interlayer insulating film is blank-etched so as to expose the surface of the sacrifice polysilicon pattern and then the exposed sacrifice polysilicon pattern is etched to form a recessed profile, in which, in the recessed portion, a predetermined thickness of sacrifice polysilicon pattern remains. On the surface of the remnant sacrifice polysilicon pattern in the recessed portion a metal film (e.g. a tungsten film) is selectively deposited. When selectively depositing of the metal film, most of remnant sacrifice polysilicon pattern is consumed. Preferably, prior to the formation of the tungsten film a pre-treatment or cleaning can be performed, using diluted HF, BOE or BCl3. This method uses the thin sacrifice polysilicon pattern as the nucleated film for the tungsten deposition and as the buffer film for preventing the underlying gate insulating film and the underlying semiconductor substrate from being damaged by the fluorine of WF6 during the tungsten deposition. In addition, the thickness of the sacrifice polysilicon pattern is controlled so that most of sacrifice polysilicon pattern is consumed during the tungsten deposition, thereby reducing the resistivity of the gate electrode substantially composed of metal such as tungsten only.

Dependencies are inferred from the claim text.