OXIDE FOR SEMICONDUCTOR LAYER OF THIN-FILM TRANSISTOR, SEMICONDUCTOR LAYER OF THIN-FILM TRANSISTOR HAVING THE SAME, AND THIN-FILM TRANSISTOR

摘要

PROBLEM TO BE SOLVED: To provide an oxide thin film for a semiconductor layer of a thin-film transistor which offers a good switching characteristic, and enables the sputtering at a high sputtering rate, and the wet etching without producing no residue.SOLUTION: The oxide for a thin-film transistor is an In-Zn-Sn-based oxide which comprises at least indium, zinc and tin. The following inequalities (2) and (4) are satisfied when In/(In+Sn)≤0.5; and the inequalities (1), (3) and (4) are satisfied when In/(In+Sn>0.5, where Zn, Sn and In denote contents (atom%) of the metal elements in the oxide: In/(In+Zn+Sn)≤0.3 (1); In/(In+Zn+Sn)≤1.4×{Zn/(Zn+Sn)}-0.5 (2); Zn/(In+Zn+Sn)≤0.83 (3); and 0.1≤In/(In+Zn+Sn) (4).