Comparative Analysis of Different Figures of Merit for Algan/Gan and Si Surrounding-Gate Field Effect Transistors (SG-Fets)

The combination of better transport properties of III-V group semiconductors along with excellent electrostatic control of surrounding gate is a promising option for the future low power electronics. Accordingly in this brief, the major figures of merit (FOM) including output current, output conductance (gd), transconductance generation factor (TGF), intrinsic gain (dB), and dynamic power dissipation are computed for surrounding-gate field effect transistors (SG-FETs) considering III-V group semiconductors and Si channel material respectively with respect to different device parameters. It is noticed that the center potential is higher in AlGaN/GaN SG-FET than Si for different values of channel length (CL), channel height (H), oxide thickness (tox), and doping concentration (Nd). The AlGaN/GaN SG-FET provides lower gd than Si for different values of CL, H, tox, and Nd as required for MOS analog circuits to achieve higher gain. The peak value of TGF and intrinsic gain is higher in AlGaN/GaN than Si SG-FET for different values of CL, H, tox, and Nd. In this work, we have analyzed the MOSFET structure for normally off operation of AlGaN/GaN high electron mobility transistors (HEMTs) to reduce dynamic power dissipation (PD). The magnitude of PD is calculated to be lower in normally off AlGaN/GaN SG-FET than Si for different values of CL, H, and tox.