MMANUFACTURING METHOD OF SEMICONDUCTOR DEVICE

摘要

A method for manufacturing a semiconductor device is provided to reduce resistance of a tungsten plug by removing TiFx and sulfuric residues using fluorocarbon and oxygen gases. An interlayer dielectric(3) is formed on a semiconductor substrate(1) with a predetermined lower structure. A via hole(4) is formed on the interlayer dielectric. A barrier layer(5) is formed along an upper surface of the resultant structure. A tungsten film for filling the via hole is formed on the barrier layer. A tungsten plug is formed by removing the tungsten film from an upper portion of the barrier layer using etch gas. A plasma etching process is performed on the resultant structure by using the etch gas and fluorocarbon and oxygen gases in order to remove completely unwanted residues therefrom. The etch gas is SF6. The barrier layer is composed of Ti and TiN.