Patent ID: 8835326
Filing Date: 2014-09-16
Classification: C09K,H01L

Abstract:
1. A method of removing a metallic hard mask and etching residues from a microelectronic device comprising steps of: providing a material stack of from, bottom to top, a dielectric capping layer, an interlevel dielectric, a dielectric hard mask, a metallic hard mask, and a patterned photoresist having at least one opening that exposes a portion of the upper surface of said metallic hard mask; transferring the at least one opening into said metallic hard mask, stopping on said dielectric hard mask by etching, wherein during said etching an entirety of said patterned photoresist is removed, while maintaining metallic hard mask portions on said dielectric hard mask; extending said at least one opening through said dielectric hard mask, into said interlevel dielectric material and stopping on said dielectric capping layer by a reactive ion etching process (RIE); applying a wet chemical composition removing at least a portion of said metallic hard mask portions from a topmost surface of said dielectric hard mask layer, said chemical composition comprising an oxidizing agent selected from the group consisting of peroxides and oxidants, a pH controlling agent selected from the group consisting of quaternary ammonium salts and quaternary ammonium alkali, and an aqueous solution, wherein the composition has a pH in the range of about 7 to about 14; and etching the material stack to open the dielectric capping layer above a copper device layer for filling the at least one opening.