Process for removing residue from a semiconductor wafer after chemical-mechanical polishing

Abstract

A method for cleaning the surface of a semiconductor wafer by removing residual slurry particles adhered to the wafer surface after chemical-mechanical polishing is provided. The semiconductor wafer is subjected to a first polishing step using a basic aqueous solution of a nonionic polymeric surfactant comprising alkylphenoxypolyethoxyethanol, preferably nonylphenoxypolyethoxyethanol, at a concentration between about 30 to about 100 ppm and a quaternary ammonium hydroxide such as TMAH at a concentration between about 2.5% and about 6% by weight. A downforce of between about 0 and 2 psi (1.4.times.10.sup.5 dynes/cm.sup.2) is applied for at least 15 seconds. A second polishing step with an applied downforce of at least 4 psi is then employed while applying purified water. The method provides at least a ten fold reduction in the number of submicronic slurry particles remaining on the wafer surface and can be completed within a commercially acceptable amount of time. In addition, particles as small as 0.007 .mu.m can be removed. The method also provides a level of accuracy in the predictability of the number of residual particles remaining on the wafer surface.

Dependencies are inferred from the claim text.