Image Number 7 for United States Patent #8304763.
A semiconductor thin film (1) that is laminated on a gate electrode (13) with a gate insulation film (15) therebetween is included. The semiconductor thin film (1) has a layered structure and includes at least two semiconductor layers (a, a'). In the semiconductor thin film (1), for example, an intermediate layer (b) composed of a material different from the two semiconductor layers (a, a') is sandwiched between the semiconductor layers (a, a'). The two semiconductor layers (a, a') are composed of an identical material and the intermediate layer (b) is composed of an insulation material. A material constituting such a layered structure is composed of an organic material. Thus, a thin-film semiconductor device and a field-effect transistor in which a decrease in the mobility caused by heating and degradation of characteristics caused by the decrease can be suppressed and the heat resistance is enhanced are provided.