Semiconductor device and manufacturing method thereof

A semiconductor device comprising:

• an insulating film;
• an oxide semiconductor film over the insulating film, the oxide semiconductor film comprising indium;
• a gate insulating film over the oxide semiconductor film;
• and
• a gate electrode over the gate insulating film, wherein the gate electrode overlaps with the oxide semiconductor film,
• wherein the insulating film has a spin density of 5×1017 spins/cm3 or more at a g value greater than or equal to 2.005 and less than or equal to 2.015 by electron spin resonance, and
• wherein the oxide semiconductor film has a spin density of less than 5×1016 spins/cm3 at a g value greater than or equal to 1.88 and less than or equal to 1.98 by electron spin resonance.

A semiconductor device comprising:

• an insulating film comprising a first region and a second region;
• an oxide semiconductor film over the insulating film, the oxide semiconductor film comprising indium, wherein the oxide semiconductor film comprises a third region and a fourth region;
• a gate insulating film over the oxide semiconductor film;
• and
• a gate electrode over the gate insulating film, wherein the gate electrode overlaps with the fourth region of the oxide semiconductor film,
• wherein the third region of the oxide semiconductor film overlaps with the first region of the insulating film,
• wherein the fourth region of the oxide semiconductor film overlaps with the second region of the insulating film,
• wherein the second region of the insulating film has a spin density of 5×1017 spins/cm3 or more at a g value greater than or equal to 2.005 and less than or equal to 2.015 by electron spin resonance, and
• wherein the third region of the oxide semiconductor film has a spin density of less than 5×1016 spins/cm3 at a g value greater than or equal to 1.88 and less than or equal to 1.98 by electron spin resonance.