Method for manufacturing active matrix substrate, and active matrix substrate

A method for manufacturing an active matrix substrate comprising:

• forming an underlayer inorganic insulating film on a substrate;
• forming a semiconductor film on the underlayer inorganic insulating film;
• patterning the semiconductor film;
• forming a gate insulating film on the semiconductor film;
• forming a gate metal film on the gate insulating film;
• and
• patterning a gate electrode from the gate metal film,
• wherein the forming of the underlayer inorganic insulating film includes applying a resist onto the underlayer inorganic insulating film, performing an ashing process of forming a surface having irregularities on a surface of the resist by a first ashing process, and, after the ashing process has been performed, roughening a surface of the underlayer inorganic insulating film by performing a second ashing process and an etching process on the underlayer inorganic insulating film, and
• in the forming of the semiconductor film, a surface of at least a part of the semiconductor film is roughened following a rough surface of the underlayer inorganic insulating film.