Comprehensive Design of Device Parameters for GaN Vertical Trench MOSFETs

IEEE Access

Shuang Liu¹  Yachao Zhang¹  Jun Luo¹  Jincheng Zhang¹  Zhihong Liu¹  Hong Zhou²  Shenglei Zhao³  Weihang Zhang³  Xiufeng Song³  Hong Zhang³  Yue Hao³ 

[1] State Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi&x2019;The Testing Center, Sichuan Institute of Solid-State Circuits, China Electronics Technology Group Corporation (CETC), Chongqing, China;an, China;

关键词: GaN vertical trench MOSFETs;    breakdown voltage;    specific on-resistance;    power figure-of-merit (FOM);   

DOI  :  10.1109/ACCESS.2020.2977381

来源: DOAJ

【 摘 要 】

In this work, device parameters for GaN vertical trench MOSFETs have been investigated systematically to further improve the device characteristics. The n^- GaN drift layer, the p⁺ GaN layer and the trench gate are designed and optimized systematically using Silvaco ATLAS 2-D simulation, in order to get the best trade-off between VBR and specific on-resistance R_on. Three-terminal breakdown curves, the electron concentration, current density and electric field strength distributions have been presented to analyze the breakdown characteristics. The correlations between different parameters and different initial conditions are considered, and the eight parameters are optimized comprehensively. After the final optimization, record high FOM of 4.8 GW/cm², V_BR of 2783 V, average electric field E_drift of 1.98 MV/cm and a low R_on of 1.6 mΩ·cm² are obtained for drift layer thickness of 14 μm. The product of the thickness L_p and doping density N_p of p⁺ GaN layer can determine the breakdown mechanism, and punch through mechanism would occur when Lp ·N_p is lower than a certain value. The results indicate there exists large optimization room for fabricated GaN vertical trench MOSFETs, and the device characteristics can be further improved through the methodology in this paper for high power and high voltage applications.

【 授权许可】

Unknown