ETCHING METHOD, PATTERN FORMING PROCESS, THIN-FILM TRANSISTOR FABRICATION PROCESS, AND ETCHING SOLUTION

摘要

An etching method is provided in which selective etching can be carried out for an amorphous oxide semiconductor film including at least one of gallium and zinc, and indium. In the etching method, the selective etching is performed using an alkaline etching solution. The alkaline etching solution contains especially ammonia in a specific concentration range.