| abstract |
An object is to provide a semiconductor device having a new structure with favorable characteristics. An oxide semiconductor layer, a source electrode and a drain electrode electrically connected to the oxide semiconductor layer, a gate insulating layer covering the oxide semiconductor layer, the source electrode, and the drain electrode, and a gate over the gate insulating layer And the source electrode and the drain electrode are semiconductor devices having an oxidized region whose side surfaces are oxidized. Note that the oxidized regions of the source electrode and the drain electrode are preferably formed by plasma treatment using high-frequency power of 300 MHz to 300 GHz and a mixed gas of oxygen and argon. [Selection] Figure 1 |