Design and Optimization of Vertical GaN PiN Diodes With Fluorine-Implanted Termination

IEEE Journal of the Electron Devices Society

Yuxin Liu¹  Kuang Sheng¹  Shu Yang¹ 

[1] College of Electrical Engineering, Zhejiang University, Hangzhou, China;

关键词: GaN-on-GaN;    breakdown voltage;    edge termination;    fluorine ion implantation;    PiN diode;   

DOI  :  10.1109/JEDS.2020.2975220

来源: DOAJ

【 摘 要 】

Gallium nitride (GaN)-based power devices enable high power density and high switching frequency for power electronics systems. For the emerging vertical GaN devices, the electric field crowding around the edge of the main junction could result in premature breakdown. It is challenging to employ the commonly used junction-based termination techniques as in Si and SiC high-voltage devices for vertical GaN devices, due to the difficulty of selective p-type doping and activation in GaN. In this work, based on the unique feature of the negatively charged F ions in GaN which can favorably modulate the edge electric field, a fluorine-implanted termination (FIT) structure for vertical GaN PiN diodes has been designed and optimized to suppress the electric field crowding at the junction edge for a higher breakdown voltage (BV). The key parameters of the FIT, including the F ion dose, the thickness and width of the FIT and the angle of the bevel structure, have been comprehensively investigated by TCAD simulations to reveal their impacts on BV. Moreover, with a tapered dose distribution in the FIT, the device can achieve a higher BV with an enlarged FIT dose window.

【 授权许可】

Unknown