Charge Trapping Layer Enabled Normally-Off β-Ga2O3MOSFET

In this work, a normally-OFF β -Ga2O3 MOSFET enabled by charge trapping layer (CTL) is demonstrated for the first time. The CTL consists of Al:HfOx 1:5 and the tunneling barrier (TB) is Al2O3/HfOx/Al2O3 stack. The developed Ga2O3 MOSFET exhibits a wide Vth tuning range to normally-OFF operation and a long-lasting retention characteristic of -0.3 V (ten years). The device obtains a breakdown voltage (BV) of 1815 V, showing high reverse blocking capability based on the proposed CTL technique. I-V and C-V analyses are carried out under various temperatures to study the mechanism and explore the charge trapping and de-trapping processes. The results indicate a promising method to achieve E-mode operation for Ga2O3 MOSFET with low charge loss and stable Vth. © 1963-2012 IEEE.