Germanium-Tin (GeSn) P-Channel Fin Field-Effect Transistor Fabricated on a Novel GeSn-on-Insulator Substrate

Germanium–tin (GeSn) p-channel fin field-effect transistor (p-FinFET) was realized on a novel GeSn-on-insulator (GeSnOI) substrate. The high-quality GeSnOI substrate was formed using direct wafer bonding technique and was layer-transferred from a 300-mm GeSn/Ge/Si donor wafer. Material quality was examined using atomic force microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, and high-resolution X-ray diffraction. The fabricated GeSn p-FinFETs exhibit a small subthreshold swing (S) of 79 mV/decade atVDSof −0.05 V (by a device withLCHof 200 nm andWFinof 30 nm), good control of short channel effects, and high intrinsic transconductance (Gm,int = 702\,\,μ S/μ matVDSof −0.5 V forLCHof 80 nm). Low-temperature mobility analysis was performed on the GeSn p-FinFETs. High effective hole mobility (μ eff) (210 cm2/V· sat 290 K and 398 cm2/V· sat 5 K) is achieved. The GeSn p-FinFETs presented in this paper exhibit the highestGm,int/SₛₐₜatVDSof −0.5 V for all the reported GeSn p-FETs to date.