OXIDE FOR SEMICONDUCTOR LAYER IN THIN-FILM TRANSISTOR, THIN-FILM TRANSISTOR, DISPLAY DEVICE, AND SPUTTERING TARGET

摘要

Provided is an oxide for a semiconductor layer, which can keep the field effect mobility thereof at a high level, has a small amount of change in threshold voltages against light, bias stress and the like and has excellent stress resistance when used in a thin-film transistor equipped with an oxide semiconductor layer thin film, and which has excellent resistance to a wet-etching solution that is used in the patterning of source and drain electrodes. The oxide for a semiconductor layer is an oxide used for a semiconductor layer in a thin-film transistor, is composed of In, Zn, Ga, Sn and O, and fulfills the requirements represented by formulae (1) to (4) shown below, wherein [In], [Zn], [Ga] and [Sn] respectively represent the content ratios (at.%) of the metal elements each relative to the total content of all of the metal elements other than oxygen in the oxide. (1) 1.67×[Zn]+1.67×[Ga] >= 100 (2) ([Zn]/0.95)+([Sn]/0.40)+([In]/0.4) >= 100 (3) [In] <= 40 (4) [Sn] >= 5