Improved Reverse Conduction in Enhancement-Mode GaN HEMTs via SBD Integration

Location: SIST 3-301

Time：16^th Jan. 2025 14:00

Host: Prof. Xinbo Zou

Abstract:

In the field of high-frequency power electronics, Gallium Nitride (GaN) devices are critical for energy efficiency; however, standard GaN High Electron Mobility Transistors (HEMTs) inherently suffer from excessive reverse voltage drops, leading to severe switching losses. Furthermore, the development of reliable enhancement-mode (e-mode) devices is frequently hindered by lattice damage caused by conventional plasma etching, such as Cl₂-based ICP etching. To address the critical challenges of lattice damage caused by conventional plasma etching, low-damage Argon-based Neutral Beam Etching (Ar-NBE) technology was investigated to realize recessed-gate HEMTs to promote the development of enhancement-mode GaN HEMTs. In contrast to other dry etching methods, it can effectively circumvent the inherent defects of plasma etching as evidenced by high threshold voltage and large saturation current. Building upon this low-damage process, this talk reports a monolithic integration strategy for improved reverse conduction performance, specifically via integrating HEMT and a Schottky Barrier Diode (SBD). This design utilizes the preferential conduction mechanism of the SBD to effectively clamp the reverse voltage drop, thereby minimizing conduction losses. Experimental results demonstrate that the fabricated devices achieve stable normally-off characteristics, delivering a synergistic combination of reduced reverse conduction loss and enhanced device reliability for high-efficiency applications.