| abstract |
A semiconductor device capable of miniaturization or high integration is provided. A semiconductor device having a transistor, the transistor comprising a first conductor, a first insulator over the first conductor, an oxide provided with a trench over the first insulator, and a first oxide disposed in a region not overlapping the trench. a second conductor and a third conductor, a second insulator disposed between the second conductor and the third conductor and also in a groove portion of the oxide, and a fourth conductor on the second insulator; The bottom surface is lower than the bottom surface of the second conductor and the bottom surface of the third conductor, and in the cross-section in the channel length direction of the transistor, the end of the bottom surface of the groove has a curvature. |