Etching solution for multilayer film, etching concentrate and etching method

摘要

Provided is an etching solution for etching a multilayer film of a thick copper layer and an underlying titanium layer, which can be used even when the metal ion concentration is 8,000 ppm or more. (A) hydrogen peroxide, (b) fluoride ion supply source, (c) azoles, (d) hydrogen peroxide stabilizer, (e) organic acid, (f) amines, (g) ) An etching solution containing water, wherein the organic acid is methanesulfonic acid and one of lactic acid, succinic acid, glutaric acid and malonic acid, or lactic acid alone.