Functionalized Metal and Nitride CMP Slurry
The invention provides a chemical mechanical polishing solution for metal and metal nitride substrates. The polishing solution includes a solvent; functionalized carbon-based particles having oxygen-containing functional groups a silica abrasive; a Fenton's catalyst or reagent and a corrosion inhibitor. The functionalized carbon-based particles have oxygen-containing functional groups that react with a peroxy moiety to increase oxygen to carbon atomic ratio on the functionalized carbon-based particles. The functionalized carbon-based particles contain at least 10 weight percent of an sp3-containing structure, the functionalized carbon-based particles include at least 0.01 atomic percent oxygen and a surface of the functionalized carbon-based particles has an atomic oxygen to carbon ratio of at least 0.01.
1 . A chemical mechanical polishing solution for metal and metal nitride substrates comprising:
a solvent;
functionalized carbon-based particles having oxygen-containing functional groups, the functionalized carbon-based particles having oxygen-containing functional groups react with a peroxy moiety to increase oxygen to carbon atomic ratio on the functionalized carbon-based particles, the functionalized carbon-based particles containing at least 10 weight percent of an sp3-containing structure, wherein the functionalized carbon-based particles include at least 0.01 atomic percent oxygen and wherein a surface of the functionalized carbon-based particles has an atomic oxygen to carbon ratio of at least 0.01;
a silica abrasive;
a Fenton's catalyst or reagent; and
a corrosion inhibitor.
2 . The polishing solution of claim 1 wherein the polishing solution includes a nitrogen-containing inhibitor for the metal or the metal nitride.
3 . The polishing solution of claim 1 wherein the surface of the functionalized carbon-based particles includes a graphene, graphite, amorphous carbon or a mixture thereof.
4 . The polishing solution of claim 1 wherein the oxygen-containing functional group is a COOH and its salts, COOOH and its salts, OH—, ketone, oxirane or a combination thereof.
5 . The polishing solution of claim 4 wherein the functionalized carbon-based particles also include an amine (NH 2 ) group, sulfonate (SO 3 ) group or hydrocarbon (C—H) groups.
6 . The polishing solution of claim 1 wherein the metal and metal nitride is selected from the group consisting of cobalt, copper, molybdenum, tungsten, titanium nitride and tantalum nitride.
7 . The polishing solution of claim 1 wherein the polishing solution includes hydrogen peroxide as the peroxy moiety and wherein the solution contains at least 0.5 μM hydroxyl radical.
8 . The polishing solution of claim 1 wherein the Fenton's catalyst or reagent is iron.
9 . The polishing solution of claim 1 wherein the functionalized carbon-based particles contain at least 30 weight percent sp3-containing structure.
10 . The polishing solution of claim 1 wherein the functionalized carbon-based particles contain at least 50 weight percent sp3-containing structure.