A 0.43 V/90 nA/mm Lateral AlGaN/GaN Schottky Barrier Diode With Plasma-Free Groove Anode Technique
Tao Zhang, Li Ruohan, Juan Lu, Yanni Zhang, Yueguang Lv, Xiaoling Duan, Shengrui Xu, Jincheng Zhang, Yue Hao
Abstract
In this letter, high-performance AlGaN/GaN Schottky barrier diodes (SBDs) with a great balance between forward and reverse characteristics are demonstrated. Benefiting from a plasma-free, low-damaged wet etching technique of an AlGaN layer at the anode region and low work-function tungsten (W) as the anode, lateral GaN SBDs with a low turn-on voltage (<inline-formula> <tex-math notation="LaTeX">$\text{V}_{{\mathrm {T}}}$ </tex-math></inline-formula>) of 0.43 V and a low reverse current (<inline-formula> <tex-math notation="LaTeX">$\text{I}_{{\mathrm {R}}}$ </tex-math></inline-formula>) of 90 nA/mm are obtained. Meanwhile, owing to the flattened self-terminated etching surface and the assistance of SiN passivation grown by low-pressure chemical vapor deposition, a high breakdown voltage of 1.83 kV and a power figure-of-merit (FOM) of 1.20 GW/cm<sup>2</sup> are achieved for the fabricated GaN SBD with a spatial distance (<inline-formula> <tex-math notation="LaTeX">$\text{L}_{{\mathrm {AC}}}$ </tex-math></inline-formula>) of <inline-formula> <tex-math notation="LaTeX">$15 ~\mu \text{m}$ </tex-math></inline-formula> from cathode to anode. The lateral GaN SBD fabricated with the optimized wet etching technique shows great potential for next-generation power electronics.