RF Nanoscale Device Modeling

Abstract

Continuous growth in the understanding of device physics and its application in modern technology has intensified the research in this field. The devices with higher carrier mobility have caught much attention to fulfill the requirement of modern communication systems. The devices with Si, the backbone of the present electronics industry, have become insufficient to meet the growing need for high-frequency communications. The new devices are being formed with ternary and quaternary compounds such as AlGaAs/GaAs and AlGaN/GaN, showing improved results. Transfer of electrons from the doped supply layer (AlGaAs or AlGaN) into the undoped channel layer (GaAs or GaN), thereby forming two-dimensional electron gas (2-DEG) in the region (undoped channel layer) where there is no impurity scattering. The absence of impurity and hence impurity scattering in the channel layer results in very high carrier mobility. Thus, research on wide bandgap ternary and quaternary compounds could help design High Electron Mobility Transistor (HEMT). The main objective of the proposed research work is to model the RF nanoscale device that has been accomplished by working on a heterojunction device called HEMT. newlineThe work shows the structures characterized by 2-DEG formed at the interface of AlGaN and GaN layers. The work has investigated various HEMT layers and optimized the different layers to obtain improved results. The research provides the models that have improved DC parameter values such as VT, gm, and IDS. Higher breakdown voltage and lower subthreshold slope are also obtained for the proposed HEMT models. The work also investigated device RF parameters such as fT and fMAX and noise parameters like Minimum Noise Figure (NFMIN), Optical Reflection Coefficient (and#915;OPT), and noise conductance (gn), which are found to be in the acceptable range. The research work also studies the gate recessing mechanism and finds it useful for enhancing gate control.