| 摘要 |
PROBLEM TO BE SOLVED: To lower the concentration of impurities contained in the vicinity of a surface on which an oxide semiconductor film is formed, to improve the crystallinity of the oxide semiconductor film, and to provide a semiconductor device having stable electric characteristics by using the oxide semiconductor film.SOLUTION: The semiconductor device has: a gate electrode 101; a gate insulating film 102 that covers the gate electrode and includes an oxide containing silicon; an oxide semiconductor film 103 that is in contact with the gate insulating film and provided in the region overlapping with at least the gate electrode; and a source electrode 105a and a drain electrode 105b which are connected with the oxide semiconductor film. In a first region of the oxide semiconductor film, where a thickness from an interface with the gate insulating film is 5 nm or less, the silicon concentration is 1.0 atom% or less. The concentration of silicon contained in the other regions than the first region of the oxide semiconductor film is lower than the concentration of silicon contained in the first region. A crystalline part is contained at least in the first region. |
