METHOD FOR FORMING TUNGSTEN PLUG OF SEMICONDUCTOR DEVICE TO IMPROVE RELIABILITY OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming a tungsten plug of a semiconductor device is provided to improve reliability of a semiconductor device by reducing a hole recess characteristic occurring in the surface of a tungsten plug while easily eliminating tungsten residue remaining in a region except a contact hole in a process for forming the tungsten plug. CONSTITUTION: A metal barrier layer(15) is formed on a semiconductor device(11) having a contact hole. A sacrificial layer(21) that has a similar etch rate in a dry etch process and a higher etch rate in a wet etch process to/than that of a tungsten layer(16) to be formed, is formed on the metal barrier layer. The sacrificial layer is patterned to be left only in the outside of the contact hole. A tungsten layer is formed on the resultant structure to sufficiently fill the contact hole. An etch-back process and a wet-etch process are sequentially performed to etch the tungsten layer and the sacrificial layer, thereby forming a tungsten plug(16A) in the contact hole.