Design and simulation analysis of GAN based HEMT for high power and high frequency applications

Abstract

High Electron Mobility Transistors (HEMTs) are distinct from traditional Field Effect Transistors (FETs), designed specifically for microwave and radio frequency (RF) applications such as microwave ovens, satellite communications, RF amplifiers, radar systems, defense and aerospace etc. Present research work focus on performance improvement of HEMT device by applying various techniques such as gate engineering, high - K technique and by adding aluminum nitride (AlN) spacer and AlN nucleation layer. Simulation analysis has been performed for different electrical characteristics such as conduction band energy diagram, electron concentration, drain current, transconductance, gate - source capacitance, gain, Y - parameter, gate leakage current and cut-off frequency etc. Initially, field plate has been placed between gate and drain to enhance the performance of the HEMT device. SiN material is used as passivation layer in the proposed HEMT device which exhibit poor performance in terms of linearity. Hence, high - K materials have been applied in the second stage of proposed work to HEMT device performance. Various passivation materials such as Al2O3, HfSiO4, HfO2, and SiO2have been considered for simulation analysis. From results it is found that, Al2O3 offer better performance as compared to other passivation materials such as SiN, HfSiO4, HfO2 and SiO2. In the third stage of proposed research work, for enhancing the performance of HEMT device, aluminum nitride (AlN) as a spacer has been placed between Aluminum Gallium Nitride (AlGaN) barrier and GaN channel. Additionally, AlN nucleation layer has been added between the channel and AlGaN back barrier layer. Silvaco TCAD simulation software has been used to analyze the proposed HEMT device. From the simulated results, electrical characteristics has been increased. In the fourth stage, the effect of thickness variation in GaN barrier layer of HEMT device has been studied. These electrical characteristics influences the proposed HEMT device performance. newline