Python/Silvaco-based Performance Simulation and Quantum Analysis of a 14 nm Si/Si3N4 Cylindrical GAA FET

This study presents a comprehensive TCAD and Python-based simulation study of an aggressively scaled (channel length is only 14 nm) cylindrical Gate-All-Around Field-Effect Transistor (CGAA FET) featuring a silicon channel and Si3N4 high-κ gate dielectric. The CGAA structure enhances superior gate control, leading to the suppression of short-channel effects and hence, its lower power consumption, whereas Si3N4 increases the drive current, leading to its high-speed operation. Using Silvaco ATLAS Technology Computer-Aided Design simulations with quantum mechanical models and postprocessing Python scripts, the device’s electrical performance, quantum confinement effects, and scalability was characterised. Key extracted parameters at VDS = 0.05 V include a threshold voltage (VT) of 0.32 V, subthreshold swing (SS) of 68.5 mV/dec, drain-induced barrier lowering (DIBL) of 36.7 mV/V, and an on/off current ratio (Ion/Ioff) of 7.8 × 107. Detailed analysis of energy band diagrams, density of states, and wave functions confirms strong quantum confinement in the 3 nm thick channel. The GAA architecture demonstrates excellent electrostatic control, making it promising for sub-10nm CMOS technology nodes.