Method of manufacturing semiconductor substrate and method of manufacturing substrate for liquid ejection head

A method of manufacturing a substrate for a liquid ejection head, the substrate including a wiring layer, an insulating layer on the wiring layer, a barrier metal layer on the wiring layer and the insulating layer, and an electrode layer on the barrier metal layer, the electrode layer being electrically connected to the wiring layer through intermediation of the barrier metal layer, the method comprising:

• forming the barrier metal layer on the wiring layer and on the insulating layer;
• forming a resist mask on the barrier metal layer;
• performing dry etching on a first portion of the barrier metal layer, which is exposed from an opening portion of the resist mask, so that the dry etching is prevented from reaching the insulating layer;
• performing wet etching on a second portion of the barrier metal layer exposed by the dry etching so that the wet etching reaches the insulating layer;
• stripping the resist mask;
• and
• forming the electrode layer on a third portion of the barrier metal layer that remains after the wet etching.