A memory transistor including a substrate, a tunnel insulating pattern on the substrate, a charge storage pattern on the tunnel insulating pattern, a blocking insulating pattern on the charge storage pattern, and a gate electrode on the blocking insulating pattern, the blocking insulating pattern surrounding the gate electrode and methods of operating and fabricating the same. A nonvolatile memory may further include a plurality of memory transistors in series and a plurality of auxiliary structures between each of the plurality of unit transistors in series. Each of the plurality of auxiliary structures may be a dummy mask pattern or an assistant gate structure.