Semiconductor device and method for manufacturing same

Abstract

A semiconductor device includes a thin film transistor including a semiconductor layer, a gate electrode, a gate insulating layer, a source electrode, a drain electrode, the semiconductor layer includes a layered structure including a first oxide semiconductor layer including In and Zn, in which an atomic ratio of In with respect to all metallic elements included in the first oxide semiconductor layer is higher than an atomic ratio of Zn, a second oxide semiconductor layer including In and Zn, in which an atomic ratio of Zn with respect to all metallic elements included in the second oxide semiconductor layer is higher than an atomic ratio of In, and an intermediate oxide semiconductor layer arranged between the first oxide semiconductor layer and the second oxide semiconductor layer, and the first and second oxide semiconductor layers are crystalline oxide semiconductor layers, and the intermediate oxide semiconductor layer is an amorphous oxide semiconductor layer, and the first oxide semiconductor layer is arranged nearer to the gate insulating layer than the second oxide semiconductor layer.