Patent ID: 6534415
Filing Date: 2003-03-18
Classification: H01L

Abstract:
A method for removing polymer residues after tungsten etch back, applicable to a multilevel metallization process, the method comprising steps of:providing a first metal layer which is formed on a metal oxide semiconductor (MOS) device and a substrate; forming a patterned dielectric layer on the first metal layer to cover the dielectric layer having an opening therein, which opening exposes a part of the metal layer; forming a conformal metal barrier layer to cover the dielectric layer and a profile of the opening; forming a tungsten layer on the conformal metal barrier layer so as to fill the opening; removing a part of the tungsten layer outside the opening until a top surface of the tungsten layer in the opening is level with top surface of the metal barrier layer; performing a brush cleaning process so as to remove polymer residues that remain on the metal barrier layer after removal of the tungsten layer; performing a plasma ashing process using a plasma containing oxygen, after the brush cleaning process to further remove remaining polymer residues on the metal barrier layer, wherein the top surface of the tungsten layer in the opening is oxidized to form a tungsten oxide film; and removing the tungsten oxide film by performing a tungsten etch back process.