A semiconductor device of an embodiment includes a silicon carbide layer, a gate electrode, a silicon oxide layer between the silicon carbide layer and the gate electrode, and containing boron, carbon, and one element of hydrogen, deuterium, and fluorine, and a region provided between the silicon carbide layer and the silicon oxide layer and having a boron concentration equal to or more than 110.sup.20 cm.sup.3. Boron concentration distribution has a peak in the region, a first concentration of boron at a first position 5 nm away from the peak toward the silicon oxide layer, a second concentration of carbon at the first position, and a third concentration of the element at the first position are equal to or more than 110.sup.18 cm.sup.3. The second concentration is 80% to 120% of the first concentration, and the third concentration is 80% to 120% of the first concentration.

This bogie and vehicle is provided with: a bogie body; a pair of travel wheels disposed on both sides of the bogie body in a direction intersecting with the traveling direction and capable of rolling motion on the traveling road surface of a track; a guide device guided along a guide rail and rotatably supported to the bogie body about the axial line along a vertical direction; and a pair of motors disposed between the pair of travel wheels of the bogie body and transferring a drive force to the pair of travel wheels.

This bogie and vehicle is provided with: a bogie body; a pair of travel wheels disposed on both sides of the bogie body in a direction intersecting with the traveling direction and capable of rolling motion on the traveling road surface of a track; a guide device guided along a guide rail and rotatably supported to the bogie body about the axial line along a vertical direction; and a pair of motors disposed between the pair of travel wheels of the bogie body and transferring a drive force to the pair of travel wheels.

A semiconductor device according to an embodiment includes a silicon carbide layer, a silicon oxide layer having a peak frequency of a longitudinal wave optical mode of 1245 cm.sup.1 or more at a position 0.5 nm away from the silicon carbide layer, and a region located between the silicon carbide layer and the silicon oxide layer and having a nitrogen concentration of 110.sup.21 cm.sup.3 or more. The concentration distribution of nitrogen in the silicon carbide layer, the silicon oxide layer, and the region has a peak in the region.

A semiconductor device according to an embodiment includes a silicon carbide layer, a silicon oxide layer having a peak frequency of a longitudinal wave optical mode of 1245 cm.sup.1 or more at a position 0.5 nm away from the silicon carbide layer, and a region located between the silicon carbide layer and the silicon oxide layer and having a nitrogen concentration of 110.sup.21 cm.sup.3 or more. The concentration distribution of nitrogen in the silicon carbide layer, the silicon oxide layer, and the region has a peak in the region.