| abstract |
Provided is a semiconductor device that improves the electrical characteristics of a semiconductor device including an oxide semiconductor and has a small variation in electrical characteristics and high reliability. A semiconductor device includes a first transistor including a first insulating film, a first barrier film over the first insulating film, a second insulating film over the first barrier film, and a first oxide semiconductor film over the second insulating film. The amount of hydrogen molecules emitted from the first insulating film at a predetermined temperature of 400°C or higher, as measured by thermal desorption spectroscopy, is 130% or less of the amount of hydrogen molecules emitted at 300°C. The second insulating film includes a region containing oxygen in a higher proportion than oxygen in the stoichiometric composition. |