ETCHING AGENT, ETCHING METHOD AND ETCHING AGENT PREPARATION LIQUID

摘要

The objective of the present invention is to provide: an etching agent for a titanium-based metal on a semiconductor substrate, which is suppressed in decomposition of hydrogen peroxide, has a long service life, and has less need for control of the hydrogen peroxide concentration in the etching agent even in cases where the etching agent is used for a semiconductor substrate that has a titanium-based metal and copper metal or a copper alloy; an etching method; and an etching agent preparation liquid which is mixed with hydrogen peroxide for use. The present invention relates to: an etching agent for a titanium-based metal on a semiconductor substrate which has the titanium-based metal and copper metal or a copper alloy arranged on top of the titanium-based metal, said etching agent being an aqueous solution that contains at least (A) hydrogen peroxide, (B) a phosphonic acid-based chelating agent having a nitrogen atom in the structure, (C) an alkali metal hydroxide and (D) an organic acid having at least one hydroxyl group and at least three carboxyl groups; an etching method which is characterized by using this etching agent; and an etching agent preparation liquid which is mixed with hydrogen peroxide for use.