Polishing composition for a tungsten-containing substrate
AssigneeCabot Microelectronics Corporation
InventorsRobert Vacassy, Dinesh N. Khanna, Alexander Simpson
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Abstract
The invention provides a method of chemically-mechanically polishing a substrate comprising tungsten through use of a composition comprising a tungsten etchant, an inhibitor of tungsten etching, and water, wherein the inhibitor of tungsten polishing is a polymer, copolymer, or polymer blend comprising at least one repeating group comprising at least one nitrogen-containing heterocyclic ring or a tertiary or quaternary nitrogen atom. The invention further provides a chemical-mechanical polishing composition particularly useful in polishing tungsten-containing substrates.
Claims13
A chemical-mechanical polishing composition comprising:
- (a) 0.0002 M to 0.4 M ferric ion,
- (b) 1 ppm to 400 ppm poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride or poly[2-(methacryloyloxy)ethyl]trimethylammonium bromide,
- (c) silica,
- (d) malonic acid,
- (e) water, and
- (f) 0.1 wt. % to 10 wt. % of hydrogen peroxide,
- wherein the polishing composition has a pH of 1 to 4.
Dependencies are inferred from the claim text.