US Patent 11777005 Semiconductor device

A transistor which is resistant to a short-channel effect is provided. The transistor includes a first conductor in a ring shape, an oxide semiconductor including a region extending through an inside of a ring of the first conductor, a first insulator between the first conductor and the oxide semiconductor, a second insulator between the first conductor and the first insulator, and a charge trap layer inside the ring of the first conductor. The charge trap layer is inside the second insulator and configured to be in a floating state.