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 (GeSnOl) substrate. The high-quality GeSnOl 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 at V-DS of -0.05 V (by a device with L-CH of 200 nm and W-Fin of 30 nm), good control of short channel effects, and high intrinsic transconductance (G(m,int) = 702 mu S/ mu m at V-DS of - 0.5 V for L-CH of 80 nm). Low-temperature mobility analysis was performed on the GeSn p-FinFETs. High effective hole mobility (mu(eff)) (210 cm(2)/V.s at 290 K and 398 cm(2)N.s at 5 K) is achieved. The GeSn p-FinFETs presented in this paper exhibit the highest G(m,int)/S-sat at V-DS of -0.5 V for all the reported GeSn p-FETs to date.