Analysis and development of I-V characteristics models for nanometer size MESFETs considering fabrication parameters

Abstract

The Metal- Semiconductor Field-Effect-Transistor (MESFET) is used as a paragon in RF amplifier due to its lower stray capacitance and immense radiation hardness. It is imperative to develop rigorous IN characteristic models for nanometer size MESFETs. Therefore, we consider two types of MESFETs, GaAs and high-power SiC MESFETs. For nanometer size GaAs MESFETs, some existing models will be analyzed and by comparing all these models Ahmed et al. model [1] has been preferred and modified. An algorithm will be developed for the optimization of model parameters to predict the I-V characteristics of nanometer range GaAs MESFETs with different aspect ratios as well as for different bias conditions. The root mean square (RMS) error technique will be used to compare the models . An improved compact nonlinear DC I-V characteristic model will also be delineated for high-power SiC MESFETs . Due to their high thermal conductivity, the SiC devices dissipate larger power resulting an extensive rise in operating temperature . This self heating increases the crystal temperature and commences a negative differential conductance (NDC) because of the change in mobility of the device. An algorithm will also be developed to find out the optimum model parameters using RMS error method. The proposed models will be compared with the experimental results. The proposed models should be a useful tool for upcoming integrated circuits with GaAs and high-power SiC MESFETs.