Design and fabrication of field-plated normally off β-Ga2O3 MOSFET with laminated-ferroelectric charge storage gate for high power application

In this work, an enhancement-mode (E-mode) beta-Ga2O3 metal-oxide-semiconductor field-effect transistor (MOSFET) has been achieved by incorporating a laminated-ferroelectric charge storage gate (L-FeG) structure [Al2O3/HfO2/Al2O3/Hf0.5Zr0.5O2 (HZO) of 10/5/2/16nm]. The band diagram between L-FeG dielectrics (Al2O3, HfO2, and HZO) and beta-Ga2O3 was determined by x-ray photoelectron spectroscopy. After applying a gate pulse with an intensity of +18V and width of 1ms, the saturation current of the E-mode device was measured to be 23.2mA/mm, which shows a negligible current reduction compared to that of 22.1mA/mm in a depletion- (D-) mode device. In addition, the threshold voltage (V-TH) is only shifted by 2.76% and 2.18%, respectively, after applying the gate stress and gate-drain stress of 15V for 10(4) s. Meanwhile, a high breakdown voltage of 2142V and specific on-resistance (R-ON,R-sp) of 23.84 m Omega.cm(2) were also achieved, which correspond to a state-of-art high power figure of merit of 192.5MW/cm(2), showing the great potential of combing the ferroelectric gate stack and lateral Ga2O3 MOSFET as next generation power devices.