A novel enhancement-mode A1GaN/GaN high electron mobility transistor (HEMT) is proposed and studied.Specifically,several split floating gates (FGs) with negative charges are inserted to the conventional MIS structure.The simulation results revealed that the Vth decreases with the increase of polarization sheet charge density and the tunnel dielectric (between FGs and AlGaN) thickness,while it increases with the increase of FGs sheet charge density and blocking dielectric (between FGs and control gate) thickness.In the case of the same gate length,the Vth will left shift with decreasing FG length.More interestingly,the split FGs could significantly reduce the device failure probability in comparison with the single large area FG structure.