AlGaN/GaN MIS-HEMT With AlN Interface Protection Layer and Trench Termination Structure

In this brief, an AlGaN/GaN metal-insulator- semiconductor high-electron-mobility transistor (MISHEMT) with pulsed laser deposited AlN interface protection layer (IPL) and trench termination (T2) structure is experimentally and theoretically investigated. The AlN IPL could effectively improve the interface quality and reduce the interface trap density, which is verified by frequency-dependent C-V measurement and conductance method. The T2structure extends the depletion region and increases the average electric field (E-field) strength between the gate and drain, achieving an enhanced breakdown voltage (BV). The measured BV and saturated output current density are 412 V and 505 mA/mm for the device at LG/LGS/LGD/WG= 1.5/1.5/5/10 μm, respectively. Compared with the MIS-HEMT without T2structure, the proposed device increases the BV by 63%.