SEMICONDUCTOR DEVICE, RFID TAG USING SAME, AND DISPLAY DEVICE

摘要

Disclosed is an oxide semiconductor layer (13) which forms a channel for a thin-film transistor and which includes at least In and oxygen and one or more types of elements from among Zn, Cd, Al, Ga, Si, Sn, Ce, and Ge. A high concentration region (13d) is disposed on one section of the oxide semiconductor layer (13), whereby said region has a maximum In concentration 30 at% or more higher than other regions on the oxide semiconductor layer (13). The film thickness of the oxide semiconductor layer (13) is 100 nm max., and the film thickness of the high concentration region (13d) is 20 nm max. or, preferably, 6 nm max. This enables a thin-film transistor with a sub-threshold coefficient of 100 mV/decade max., a high on-current, and a high field effect mobility to be achieved.