Abstract: It is known that when etching gold films using etching solutions containing iodine and iodide, N-methyl-2-pyrrolidinone (NP) is added to improve the etching solution's wettability, microfabrication property, and solution life. However, in recent years, the use of NMP has been regulated due to its adverse effects on human health. The present invention provides an etching solution and etching method for gold film that improves wettability, microfabrication property, and solution life without containing NP. In order to address the problem of the prior art, the present invention provides etching solutions and etching methods for gold films that improve wettability, microfabrication property, and liquid life without NMP, characterized by the inclusion of a specific organic solvent in the etching solution containing iodine and iodide.

Abstract: The present invention addresses the problem of providing a remover composition which can sufficiently remove ruthenium (Ru) remaining on substrates and can be inhibited from evolving RuO4 gas. The remover composition, which is for removing ruthenium remaining on substrates, has a pH at 25° C. of 8 or higher and includes one or more pH buffer ingredients.

Abstract: The present invention addresses the problem of providing a remover composition which can sufficiently remove ruthenium (Ru) remaining on substrates and can be inhibited from evolving RuO4 gas. The remover composition, which is for removing ruthenium remaining on substrates, has a pH at 25° C. of 8 or higher and includes one or more pH buffer ingredients.