Combination, method, and composition for chemical mechanical planarization of a tungsten-containing substrate
View Patent ↗A combination, composition and associated method for chemical mechanical planarization of a tungsten-containing substrate are described herein which afford tunability of tungsten/dielectric selectivity and low selectivity for tungsten removal in relation to dielectric material. Removal rates for both tungsten and dielectric are high and stability of the slurry (e.g., with respect to pH drift over time) is high.
1. A combination of a chemical mechanical polishing composition in contact with a substrate surface having at least one feature thereon comprising tungsten and at least one feature thereon comprising a dielectric material, said combination comprising:
a substrate comprising submicron integrated circuits and having a surface having at least one feature thereon comprising tungsten, said substrate surface contacting a chemical mechanical polishing composition comprising;
a)periodic acid;
b)an abrasive;
c) an amino-alcohol compound
wherein
said periodic acid and said abrasive are present in a combined amount sufficient to render the substrate surface substantially planar and to maintain a removal rate of tungsten of at least 800 Angstroms per minute upon chemical-mechanical polishing thereof when polishing is done at 4 psi of down force; and
a tunable tungsten/dielectric selectivity ranging from 0.5 to 1.5 is realized upon chemical-mechanical polishing the substrate using the composition.
2. The combination of claim 1 , wherein the dielectric material is a silicon oxide.
3. The combination of claim 1 , wherein the amino-alcohol compound is selected from the group consisting of 2-(2-aminoethoxy)ethanol, 2-(2-aminoethylamino)ethanol, diethanolamine, ethanolamine, triethanolamine and mixtures thereof.
4. The combination of claim 3 wherein the amino-alcohol compound is 2-(2-aminoethoxy)ethanol.
5. The combination of claim 1 , further comprising a pH-adjusting agent, wherein the composition has a pH ranging from pH 2 to pH 4.
6. The combination of claim 1 , wherein the periodic acid is present in an amount from 0.1 weight percent to 5 weight percent.
7. The combination of claim 1 , wherein the abrasive is present in an amount from 0.1 to 15 weight percent.
8. The combination of claim 1 wherein the selectivity depends upon the amount of abrasive in relation to the amount of periodic acid.