An enhancement mode III-Nitride device has a floating gate spaced from a drain electrode which is programmed by charges injected into the floating gate to form a permanent depletion region which interrupts the 2-DEG layer beneath the floating gate. A conventional gate is formed atop the floating gate and is insulated therefrom by a further dielectric layer. The device is a normally off E mode device and is turned on by applying a positive voltage to the floating gate to modify the depletion layer and reinstate the 2-DEG layer. The device is formed by conventional semiconductor fabrication techniques.