I-Shaped SiGe Fin Tunnel Field-Effect Transistor with High ION/IOFF Ratio

In this paper, we propose an I-shaped SiGe fin tunnel field-effect transistor (TFET) and use technology computer aided design (TCAD) simulations to verify the validity. Compared to conventional Fin TFET on the same footprint, a 27% increase in the effective channel width can be obtained with the proposed TFET. The proposed Fin TFET was confirmed to have 300% boosted on-current (Ion), 25% reduced subthreshold swing (SS), and 52% lower off-current (Ioff) than conventional Fin TFET through TCAD simulation results. These performance improvements are attributed to increased effective channel width and enhanced gate controllability of the I-shaped fin structure. Furthermore, the fabrication process of forming an I-shaped SiGe fin is also presented using the SiGe wet etch. By optimizing the Ge condensation process, an I-shaped SiGe fin with a Ge ratio greater than 50% can be obtained.