Patent attributes
A thin film field effect transistor has at least a gate electrode 2, a gate insulating layer 3, an active layer 4, a source electrode 5-1 and a drain electrode 5-2 on a substrate 1. The active layer includes an amorphous oxide semiconductor including at least In and Zn, a first interface layer 61 is disposed between the gate insulating layer and the active layer such that it is adjacent to at least the active layer, and a second interface layer is disposed on the opposite side of the active layer with respect to the first interface layer such that it is adjacent to the active layer. A content of Ga or Al in the amorphous oxide semiconductor of each of the first interface layer and the second interface layer is higher than a content of Ga or Al in the amorphous oxide semiconductor of the active layer.
