Semiconductor device and display device including the semiconductor device

A semiconductor device comprising:

• a gate electrode;
• an insulating film over the gate electrode;
• an oxide semiconductor film over the insulating film;
• and
• a pair of electrodes over the oxide semiconductor film,
• wherein the oxide semiconductor film comprises a first oxide semiconductor film and a second oxide semiconductor film over the first oxide semiconductor film,
• wherein the first oxide semiconductor film is In oxide or In—Zn oxide,
• wherein the second oxide semiconductor film is In-M-Zn oxide,
• wherein M is Al, Ga, or Y, and
• wherein the second oxide semiconductor film comprises a region where a number of the In atoms is greater than or equal to 40% and less than or equal to 50% of a total number of the In atoms, the M atoms, and the Zn atoms, and a region where a number of the M atoms is greater than or equal to 5% and less than or equal to 30% of the total number of the In atoms, the M atoms, and the Zn atoms.