| abstract |
A transistor including an oxide semiconductor film is provided. Alternatively, a transistor including an oxide semiconductor film with reduced oxygen vacancies is provided. Alternatively, a transistor with excellent electrical characteristics is provided. A first insulating film, a first oxide semiconductor film, a gate insulating film, and a gate electrode are provided. The first insulating film includes a first region, a second region, and a second region. The first region is a region that is less likely to transmit oxygen than the second region, and the first oxide semiconductor film is a semiconductor device disposed at least on the second region. [Selection] Figure 1 |