Semiconductor device

A semiconductor device comprising:

• an oxide semiconductor layer and a first electrode overlapping with each other;
• a first insulating layer between the first electrode and the oxide semiconductor layer, the first insulating layer being in contact with a first surface of the oxide semiconductor layer;
• a second insulating layer in contact with a second surface of the oxide semiconductor layer, the second surface being on a side opposite to the first surface;
• and
• a pair of second electrodes in electrical contact with the oxide semiconductor layer,
• wherein the second insulating layer includes silicon, oxygen, and nitrogen oxide,
• wherein the second insulating layer includes a portion whose spin density measured by electron spin resonance spectroscopy is greater than or equal to 1×1017 spins/cm3 and less than 1×1018 spins/cm3,
• wherein an electron spin resonance spectrum of the portion has a first signal that appears at a g-factor in a range greater than or equal to 2.037 and less than or equal to 2.039, a second signal that appears at a g-factor in a range greater than or equal to 2.001 and less than or equal to 2.003, and a third signal that appears at a g-factor in a range greater than or equal to 1.964 and less than or equal to 1.966, and
• wherein the first signal, the second signal, and the third signal are attributed to the nitrogen oxide.