Patent ID: 6395635
Filing Date: 2002-05-28
Classification: H01L

Abstract:
A method of polishing and buffing the surface of a layer of Inter Level Dielectric (ILD) on the surface of a semiconductor substrate during fabricating of a semiconductor device, said polishing and buffing using pads of selected abrasive characteristics, comprising the steps of:providing a semiconductor substrate having a surface having elevated regions and recessed regions therein having tungsten plugs grown within said layer of ILD; providing a polishing and buffing tool, said polishing and buffing tool comprising first, second and third polishing and buffing platens whereupon pads of selected abrasive characteristics have been provided, then; applying a three-step polishing procedure to the surface of said layer of ILD, using said first platen, said applying a three-step polishing procedure is DI water polishing followed by oxide slurry polishing followed by DI water polishing, said three-step polishing procedure removing tungsten residue from the surface of said layer of ILD, then; applying a two-step buffing procedure to the surface of said layer of ILD, using said second polishing pad, wherein said two step buffing procedure is oxide slurry buffing followed by DI water buffing, said two-step buffing procedure removing about 1000 Angstrom of oxide from the surface of said layer of ILD, thereby reducing micro-scratch in the surface of said layer of ILD without incurring new micro-scratch; and, then applying a DI water rinse to the surface of said layer of ILD.