基于表面势的GaN HEMT集约内核模型

A Surface-Potential-Based Compact Core Model for GaN HEMTs

从器件表面势机理出发,考虑载流子浓度升高时费米势的变化,首次在二维泊松方程中引入新的费米势近似式,重构表面势源头方程,提出了一种直接基于表面势建立氮化镓高电子迁移率晶体管(GaN HEMT)器件模型的方法,建立了包括积累区和过渡区的物理基集约内核模型。表面势引入模型突破了现有的建模技术,给集约模型的建立提供可信的内核模型方程和理论基础。模型采用解析近似求解获得表面势,Pao-Sah模型验证可行性,I-V、C-V特性曲线与TCAD软件仿真的结果有很好的拟合,能准确描述各种偏置条件下GaN HEMT的电流、电荷特性。

This paper presents a simplified method which can model GaN High Electron Mobility Transistor （HEMT） based on the surface-potential. Considering the mechanism of surface-potential and the diversification of high density of the carrier concentration, we first integral of the quasi-Fermi potential effect to the equation and built the new source equation of the surface-potential, and finish the explicit surface-potential-based compact core model which includes the accumulation and transitional region physics-based modeling. This modeling approach will break the existed modeling technology and provide creditable core equation and theoretical foundation. The SP-based compact core model for GaN HEMTs is verified by the Pao Sah implicit model and have good compliable with TCAD data over the applied terminal biases. This SP-based model can more accurately predict GaN HEMT current and charge behavior under varying operating conditions.