Performance enhancement in 3D transistors: A TCAD simulation-based study of FinFETs and GAAFETs with novel source-drain extensions.
Abstract
A novel doping-based source/drain extension structure is introduced in three-dimensional field-effect transistors (3-D FETs), namely silicon-on-insulator (SOI) FinFETs and gate-all-around (GAA) FETs. Detailed TCAD simulation including the quantum mechanical effects demonstrates that compared to conventional devices with lightly doped drain (LDD) extensions of the same footprint, the proposed devices exhibit superior suppression of short-channel effects (SCEs), with higher on-state current (Ion), switching ratio (ION/IOFF), lower subthreshold swing (SS), and drain-induced barrier lowering (DIBL) achieved. In terms of intrinsic gain (Av), the proposed FinFET achieves a peak gain of 27.5 dB, significantly higher than the 22.2 dB of the LDD counterpart. The proposed GAAFET reaches a maximum value of 28.5 dB, compared to 19.8 dB for the LDD GAAFET. Such performance advantages demonstrate the potential of the proposed devices in both digital and analog circuit applications. Fabrication process to form the GAAFETs with the novel source/drain extensions is also discussed based on the bottom-up approach.
