Surface Potential Based Compact I-V Model for GaN HEMT Devices

C. Chang, J. He, C. Li, Y. He, J. Liu, X. He, J. Pan, G. Hu, Y. Ren
SoC Key Laboratory, Peking University Shenzhen Institute and PKU-HKUST Shenzhen-Hong Kong Institution,

Keywords: GaN- HEMTs, compact model, device physics, SPICE, circuit simulation, RF and power application


Gallium Nitride (GaN)-based high electron mobility transistors (HEMTs) are emerging as promising contenders to replace existing Silicon and Gallium Arsenide (GaAs) devices in the radio-frequency/microwave power amplifiers and high-power switching applications. Along with the fast development of device technology and circuit integration, compact models for GaN HEMTs are of great value for circuit design and simulation. In this paper, an analytical drain current model for GaN HEMTs is developed based on the definition of surface potential. The electrostatic potential solution is provided first by solving the charge control equations. Based on the surface potential model, a close formed and SPICE friendly drain current model is developed for GaN HEMTs which captures the core physics and some additional effects in HEMT devices. Then, the model is calibrated and validated with TCAD simulations, and the experimental I-V measurements of fabricated devices.