摘要 |
In a semiconductor device including an oxide semiconductor layer, a conductive layer is formed in contact with a lower portion of the oxide semiconductor layer and treatment for adding an impurity is performed, so that a channel formation region and a pair of low-resistance regions between which the channel formation region is sandwiched are formed in the oxide semiconductor layer in a self-aligned manner. Wiring layers electrically connected to the conductive layer and the low-resistance regions are provided in openings of an insulating layer. |