US Patent 9768279 Semiconductor device and manufacturing method thereof

To provide a transistor formed using an oxide semiconductor film with reduced oxygen vacancies. To provide a semiconductor device that operates at high speed. To provide a highly reliable semiconductor device. To provide a miniaturized semiconductor device. The semiconductor device includes an oxide semiconductor film; a gate electrode overlapping with the oxide semiconductor film; a gate insulating film between the oxide semiconductor film and the gate electrode; and a protective insulating film that is above the oxide semiconductor film, the gate electrode, and the gate insulating film and includes a region containing phosphorus or boron.