基于有效栅长的改进型T型栅HEMT紧凑模型

Advanced SPICE Model for high electron mobility transistor (ASM-HEMT) is one of the industry standard models for GaN-based high electron mobility transistors (HEMTs), in which there still lack analytical models for the distribution of the physical properties inside the device, especially a model for the distribution of the transverse electric field ( E_ X ) and carrier concentration ( n_ S ) that can be linked to the drain current ( I_ DS ) and gate charge ( Q_ G ). Besides, the modeling of operations in the saturation region in ASM-HEMT is dependent on empirical parameters without physical significance. In this work: 1) effective gate length ( L_ G,eff ) as a core parameter for saturation region modeling is calculated to capture the velocity saturation occurring in HEMTs; 2) distribution of E_ X and n_ S varying with gate and drain biases in the linear and saturation regions is modeled; 3) a field plate (FP) aware T-gate HEMT model is developed to capture the reduction of the peak electric field and the additional parasitic effect caused by the FP. The model is verified by characterizing the I_ DS and Miller capacitance ( C_ GD ) of the fabricated T-gate HEMTs, with RMSE lower than 7.5%, indicating a high degree of agreement.