Compositions for use in chemical mechanical polishing

A method of for performing a chemical mechanical polishing process, comprising:

• contacting a surface of a substrate with a non-aqueous polishing composition, the non-aqueous polishing composition consisting of:
• abrasive particles present in an amount from about 0.01% to about 10% by weight;
• an oxidizing agent present in an amount from about 0.01% to about 10% by weight;
• a chelating agent present in an amount from about 0.01% to about 10% by weight;
• a corrosion inhibitor present in an amount from about 0.01% to about 10% by weight;
• a pH adjusting agent present in an amount from about 0.01% to about 10% by weight;
• and
• a non-aqueous solvent in an amount sufficient to disperse the abrasive particles, the chelating agent, the corrosion inhibitor and the pH adjusting agent, wherein the non-aqueous is selected from the group consisting of a glycol, a glycerin and a sulfoxide;
• polishing the surface of the substrate with a polishing pad.

A method of forming a semiconductor structure, comprising:

• etching a dielectric layer over a substrate to form a contact opening;
• depositing a barrier layer over sidewalls and a bottom of the contact opening and over a top surface of the dielectric layer, the barrier layer comprising a first metal;
• depositing a conductive material layer over the barrier layer to fill the contact opening, the conductive material layer comprising a second metal different from the first metal;
• and
• performing a chemical mechanical polishing (CMP) process to remove portions of the barrier layer and the conductive material layer over the top surface of the dielectric layer, wherein performing the CMP process comprises contacting the barrier layer and the conductive material layer with a polishing composition, the polishing composition consisting of abrasive particles, an oxidizing agent, a chelating agent, a corrosion inhibitor, a pH adjusting agent and a non-aqueous solvent in an amount sufficient to disperse the abrasive particles, the chelating, agent, the corrosion inhibitor and the pH adjusting agent, wherein the non-aqueous solvent is selected from the group consisting of a glycol, a glycerin and a sulfoxide, and wherein the polishing composition is substantially free of water such that no galvanic reaction is occurred between the first metal and the second metal during the CMP process due to the presence of water.