Patent ID: 6114249
Filing Date: 2000-09-05
Classification: C09K,H01L

Abstract:
A method for controlling the polishing rate of a material in a multiple material substrate comprising:providing a substrate having a first film formed of a first material having a first thickness and a second film formed of a second material underlying at least portions of said first film;providing a slurry which reacts with said first film and said second film;removing a major portion the thickness of said first film by chemical mechanically polishing said substrate with said slurry;without interrupting the polishing of said substrate, modifying the composition of said slurry by adding triethanolamine to the slurry in an amount sufficient to increase the selectivity of the polish rate of the slurry to the first film with respect to the second film;continuing to polish said substrate to remove a remaining portion of the first film by chemical mechanically polishing said substrate with said slurry containing triethanolamine; andinterrupting said polishing when said first film is completely removed from said underlying portions of said second film whereby portions of said second film are exposed and said first film is substantially coplanarly aligned with said second film.