Influence of Buffer Length and Mole Fraction on Analog Performances of a Symmetrical Underlapped DG Si/SiGe-based MOS-HEMT Device

The Authors through this paper have investigated and performed an in-depth study of the Analog performances of an Underlapped Dual Gate (U-DG) Si/SiGe Metal Oxide Semiconductor-High Electron Mobility Transistor (MOS-HEMT) device consisting of HfO2 as a high-k Gate dielectric material. The authors compared the aforementioned device by varying the central Si buffer length sandwiched in between the transcending Silicon Germanium (SiGe) layers and by varying the mole fraction of the SiGe layer. The study focuses on the effect of the conduction band energy profile along with various analog parameters, Drain (Id) and Gate (Ig) Currents, Transconductance (gm), and the Transconductance Generation Factor (TGF). Results show that a buffer length of 30 nm and mole fraction of 0.1 for Si in SiGe gave the best performance. The analysis showed that utilizing a 30 nm buffer length resulted in an increase in Id by a minimum of 41.6% and gm by 1.5% compared to other buffer lengths. Moreover, a mole fraction of 0.1 increases the Id by 4.5% and the gm by 1.9%.