A semiconductor device includes: a gate line; a hole extending through the gate line; a channel layer extending lengthwise in a first direction in the hole; a ferroelectric layer arranged between the channel layer and the gate line and extending lengthwise in the first direction in the hole; and a multi-tunneling dielectric structure arranged between the ferroelectric layer and the gate line and extending lengthwise in the first direction in the hole, wherein the multi-tunneling dielectric structure includes: a first silicon oxide film contacting the gate line; a second silicon oxide film spaced apart from the first silicon oxide film in a second direction and contacting the ferroelectric layer, wherein the second direction crosses the first direction; and a silicon oxynitride film disposed between the first silicon oxide film and the second silicon oxide film.