Semiconductor device, polycrystalline semiconductor thin film, process for producing polycrystalline semiconductor thin film, field effect transistor, and process for producing field effect transistor

摘要

An object of the present invention is to provide a novel semiconductor device which is excellent in stability, uniformity, reproducibility, heat resistance, durability and the like, and can exert excellent transistor properties. The semiconductor device is a thin-film transistor, and this thin-film transistor uses, as an active layer, a polycrystalline oxide semiconductor thin film containing In and two or more metals other than In and having an electron carrier concentration of less than 1×1018/cm3.