| abstract |
The invention is an aqueous slurry useful for chemical mechanical polishing a semiconductor substrate having cobalt or cobalt alloy containing features containing Co 0 . The slurry includes 0.1 to 2 wt % hydrogen peroxide oxidizing agent (α), 0.5 to 3 wt % colloidal silica particles (β), a cobalt corrosion inhibitor, 0.5 to 2 wt % complexing agent (γ) selected from at least one of L-aspartic acid, nitrilotriacetic acid, nitrilotri(methylphosphonic acid), ethylenediamine-N,N′-disuccinic acid trisodium salt, and ethylene glycol-bis (2aminoethylether)-N,N,N′,N′-tetraacetic acid, and balance water having a pH of 5 to 9. The total concentrations remain within the following formulae as follows: wt % (α)+wt % (β)=1 to 4 wt % for polishing the cobalt or cobalt alloy; wt % (γ)≤2*wt % (α) for limiting static etch of the cobalt or cobalt alloy; and wt % (β)+wt % (γ)≤3*wt % (α) for limiting static etch. |