Abstract: [Object] To provide a sputtering target for producing an oxide semiconductor thin film having high properties, which serves as a substitute for IGZO, and a method of producing the same. [Solving Means] In order to achieve the above-mentioned object, a sputtering target according to an embodiment of the present invention includes: an oxide sintered body including indium, tin, and germanium, in which an atom ratio of germanium with respect to a total of indium, tin, and germanium is 0.07 or more and 0.40 or less, and an atom ratio of tin with respect to the total of indium, tin, and germanium is 0.04 or more and 0.60 or less. As a result, it is possible to achieve transistor characteristics of having mobility of 10 cm2/Vs or more.

Abstract: A thin-film transistor according to an embodiment of the present invention includes: a gate electrode; an active layer formed of an oxide containing indium, zinc, and titanium; a gate insulating film formed between the gate electrode and the active layer; and a source electrode and a drain electrode that are electrically connected to the active layer. Atomic proportions of elements relative to the total quantity of indium, zinc, and titanium that constitute the oxide may be not less than 24 at. % and not more than 80 at. % for indium, not less than 16 at. % and not more than 70 at. % for zinc, and not less than 0.1 at. % and not more than 20 at. % for titanium.

Abstract: An oxide-sintered-body sputtering target according to an embodiment of the present invention is formed of a sintered body containing an indium oxide, a zinc oxide, a titanium oxide, and a zirconium oxide, an atomic ratio of titanium with respect to a sum of indium, zinc, and titanium being not less than 0.1% and not more than 20%, a weight ratio of zirconium with respect to a sum of the indium oxide, the zinc oxide, the titanium oxide, and the zirconium oxide being not less than 10 ppm and not more than 2,000 ppm.

Abstract: A thin-film transistor according to an embodiment of the present invention includes: a gate electrode; an active layer formed of an oxide containing indium, zinc, and titanium; a gate insulating film formed between the gate electrode and the active layer; and a source electrode and a drain electrode that are electrically connected to the active layer. Atomic proportions of elements relative to the total quantity of indium, zinc, and titanium that constitute the oxide may be not less than 24 at. % and not more than 80 at. % for indium, not less than 16 at. % and not more than 70 at. % for zinc, and not less than 0.1 at. % and not more than 20 at. % for titanium.