The present invention is directed to a microetching composition comprising a source of cupric ions, acid, a nitrile compound, and a source of halide ions. Other additive, including organic solvents, a source of molybdenum ions, amines, polyamines, and acrylamides may also be included in the composition of the invention. The present invention is also directed to a method of microetching copper or copper alloy surfaces to increase the adhesion of the copper surface to a polymeric material, comprising the steps of contacting a copper or copper alloy surface with the composition of the invention, and thereafter bonding the polymeric material to the copper or copper alloy surface.