Copper-passivating CMP compositions and methods
View Patent ↗The present invention provides chemical-mechanical polishing (CMP) methods and compositions for polishing copper-containing substrates. The methods of the present invention entail abrading a surface of a copper-containing substrate with a CMP composition of the invention, preferably in the presence of an oxidizing agent (e.g., hydrogen peroxide). The CMP compositions of the invention comprise a particulate abrasive, a copper-complexing agent, a copper-passivating agent bearing an acidic OH group and an additional oxygen substituent in a 1,6 relationship to the acidic OH group, and an aqueous carrier. A preferred composition of the invention comprises about 0.01 to about 1 percent by weight of the particulate abrasive, about 0.1 to about 1 percent by weight of the copper-complexing agent, about 10 to about 1000 ppm of the copper-passivating agent.
1. A chemical-mechanical polishing (CMP) composition for polishing a copper-containing substrate, the composition comprising:
(a) about 0.01 to about 1 percent by weight of a particulate abrasive;
(b) about 0.1 to about 1 percent by weight of copper-complexing agent;
(c) about 10 to about 1000 parts-per-million (ppm) a copper-passivating agent that comprises an o-hydroxyaryl hydroxamic acid compound, a salt thereof, or a partially neutralized form thereof; and
(d) an aqueous carrier therefor.
2. The composition of claim 1 wherein the o-hydroxyaryl hydroxamic acid compound is salicylhydroxamic acid, a salt thereof, or a partially neutralized form thereof.
3. The composition of claim 1 wherein the copper-complexing agent is selected from the group consisting of oxalic acid, an amino-substituted carboxylic acid, a hydroxyl-substituted carboxylic acid, a salt thereof, a partially neutralized form thereof and a combination of two or more of the foregoing.
4. The composition of claim 1 wherein the copper-complexing agent comprises an amino-substituted carboxylic acid, a salt thereof, or a partially neutralized form thereof.
5. The composition of claim 1 wherein the copper-complexing agent comprises a hydroxyl-substituted carboxylic acid, a salt thereof, or a partially neutralized form thereof.
6. The composition of claim 1 wherein the particulate abrasive comprises silica.
7. The composition of claim 1 wherein the particulate abrasive as a mean particle size of not more than about 100 nm.
8. The composition of claim 1 further comprising about 0.1 to about 5 percent by weight of an oxidizing agent.
9. The composition of claim 8 wherein the oxidizing agent is hydrogen peroxide.