SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device having a configuration capable of preventing degradation of electrical characteristics associated with its miniaturization.SOLUTION: The semiconductor device includes: a stacked layer on an insulating surface, including the stack of a first oxide semiconductor layer and a second oxide semiconductor layer in this order; and a third oxide semiconductor layer formed so as to cover a part of a surface of the stacked layer. The third oxide semiconductor layer has a first layer in contact with the stacked layer and a second layer on the first layer. The first layer is formed by a microcrystalline layer, and the second layer is formed by a crystalline layer in which its c-axis is oriented in the vertical direction with respect to a surface of the first layer.