Performances Analysis for Core-Shell Si/InxGa1-xAs FinFET

In this article, we propose the novel core-shell Si/InxGa $_{{1}- {x}}$ As FinFETs, where an In $_{{0}.{53}}$ Ga $_{{0}.{47}}$ As shell channel was epitaxially grown on a silicon core fin. Based on the model calibrated using conventional bulk In $_{{0}.{53}}$ Ga $_{{0}.{47}}$ As FinFET, the device characteristics, including dc and RF performance of the core-shell FinFET, were analyzed and compared with the bulk FinFET. Due to the conduction band offset between InxGa $_{{1}- {x}}$ As shell and Si fin, a quantum well is formed in the InxGa $_{{1}- {x}}$ As channel region, which is lying between the high dielectric constant (HK) gate and the Si core. The advantages of the core-shell FinFET include increasing the gate controllability, enhancing the effective bandgap, and reducing the leakage current, while the on-state performance in transconductance ( ${g}_{m}\text {)}$ and drain current ( ${I}_{\text {ON}}\text {)}$ is maintained. The effects of varying the channel thickness, length, and the indium content of the InxGa $_{{1}- {x}}$ As shell are also explored in both dc and RF aspects. The results show that the core-shell FinFET exhibits superior characteristics in terms of leakage current, subthreshold swing, and drain-induced barrier lowering, owing to its superior gate controllability, with comparable RF performance in current gain cutoff frequency ( ${f}_{t} \gt 400$ GHz for 50-nm ${L}_{\text {Ch}}\text {)}$ with the bulk FinFET. The major objective of this article is to provide the possible directions for the design of the Si/InxGa $_{{1}- {x}}$ As core-shell FinFET for future device applications.