Patent ID: 7314578

Claim:
An abrasive slurry composition for the chemical-mechanical polishing of a polysilicon layer formed over structures including silicon nitride comprising: a carrier liquid; abrasive particles; and a non-ionic surfactant that selectively forms a passivation layer on exposed surfaces of the polysilicon layer wherein the non-ionic surfactant includes ethylene oxide-propylene oxide block copolymer alcohols selected from the group consisting of a first group of alcohols represented by the formula I CH 3 —(CH 2 ) n —(CH(CH 3 )CH 2 O) y —(CH 2 CH 2 O) x —OH (I) wherein n is an integer satisfying the relationship 3≦n≦22; y is an integer satisfying the relationship 1≦y≦30; and x is an integer satisfying the relationship 1≦x≦30; and a second group of alcohols represented by the formula II R 2 —C 6 H 4 O—(CH(CH 3 )CH 2 O) y —(CH 2 CH 2 O) x —OH (II) wherein R 2 is —C 9 H 19 or —C 8 H 17 .