Vertical β-Ga₂O₃ Schottky Barrier Diodes With Field Plate Assisted Negative Beveled Termination and Positive Beveled Termination
Chen Hu, Hengyu Wang, Kuang Sheng
Abstract
In this letter, high performance vertical <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ga2O3 (001) Schottky Barrier Diodes (SBD) with field plate assisted negative beveled (FP-NB) and positive beveled (PB) termination are reported. For the SBD with FP-NB structure, the electrical field crowding is substantially suppressed owing to the field plate which is extended over the bevel. The reverse leakage current is reduced and the breakdown voltage of FP-NB SBD is improved over 1100V. A low differential ON-resistance of 2.6 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{m}\Omega \cdot $ </tex-math></inline-formula> cm2, and a high <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{{\text {on}}}/{I}_{{\text {off}}}$ </tex-math></inline-formula> ratio over <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{9}}$ </tex-math></inline-formula> is achieved through etching recipe improvement, positive bevel with 67° mesa angle is successfully fabricated. The electric field crowding in SBD with PB termination is further suppressed owing to the reduction of positive charge at the edge. As a result, the breakdown voltage is significantly improved up to 1710 V. A Baliga’s figure of merit (FOM) of 0.80 GW/cm2 is achieved. Vertical <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ga2O3 SBDs with FP-NB and PB termination show the great potential for future power rectifiers.