Research On Large-signal Model Of Surface Potential-based GaAs PHEMT

With the enthusiasm of the 5G era,Ga As-based p HEMT devices with highfrequency,low-noise,and low-loss characteristics has significant advantage in highfrequency power amplifiers used in 5G base stations.Contemperory semiconductor device modeling technology can characterize the electrical characteristics of Ga As p HEMT accurately,guiding the process structure optimization and improve the yield of products.In indestury practicing,Ga As p HEMT modeling highly relies on empiricalbased models.Frankly speaking,physical-based model starts from device carrier transport mechanism combining with energy level theory,Poisson's equation,etc,which has fewer parameters,higher-order derivative convergence and better scalability.5G communication has strict requirements in high linearity and high output power,which urgely needed a set of physical-based large signal models to describe Ga As p HEMT.This paper develops a physical-based current and charge model for Ga As p HEMT using the surface-potential ASM core equation.The main contents are as follows:(1)A brief introduction to the advantages of Ga As materials as well as the structure,working principle and basic electrical characteristics of Ga As p HEMT.Small signal and large signal testing system and process of Ga As p HEMT are studied based on RF on-chip testing technology,.(2)The core potential equation of the ASM model is deduced in detail,and the underlying principle of the surface-potential model is explained more deeply,which provides a strong theoretical support for the later establishment of a large signal model for the Ga As p HEMT based on the surface potential theory.(3)A physical-based large signal model of Ga As p HEMT is developed based on the core equation of the ASM.A topology structure of the large signal model has been developed.An extraction paramerter method of the small signal model is proposed and the development mechanism of the large signal model based on the surface potential for the Ga As p HEMT is analyzed.Combined with the measured data of the device provided by a domestic 0.5um process line,the parameter extraction process of the large signal model is elaborated.(4)The small signal S-parameter and nonlinear power characteristics of the large signal model of the surface-potential-based Ga As p HEMT are verified,and a scalable model of the surface-potential-based Ga As p HEMT is established under the 0.5um process.The results show that the surface-potential-based large signal model proposed in this paper has high accuracy,third-order convergence and flexible scalability in the25MEG-40.025 GHz frequency band,which also meets the nonlinear indicators such as the maximum output power of the device.