In this letter, the authors present the capacitance-voltage and current-voltage characteristics of TaN∕HfO2∕n-GaAs metal-oxide-semiconductor capacitors with thin silicon and germanium interfacial passivation layers (IPLs). Physical vapor deposition high-k dielectric films and silicon/germanium IPLs were deposited on GaAs substrate which has been cleaned with HCl and (NH4)2S solutions. Equivalent oxide thickness (EOT) of 12.5Å and dielectric leakage current density of 2.0×10−4A∕cm2 at ∣VG−VFB∣=1V with low capacitance-voltage frequency dispersion have been obtained. The results indicate that the use of a thin silicon/germanium IPL assists in scaling EOT below 13Å, while improving the quality of the interface.
We present the capacitance-voltage characteristics of TaN∕HfO2∕n-GaAs metaloxide-semiconductor capacitors, with an equivalent oxide thickness (EOT) of 10.9Å, low frequency dispersion, and a low leakage current density (Jg) of ∼10−6A∕cm2 at ∣VG−VFB∣=1V. Physical vapor deposited high-k dielectric film (HfO2) and a thin germanium (Ge) interfacial control layer (ICL) were used to achieve the low EOTs. As postdeposition annealing (PDA) time increases beyond a critical point, EOT and Jg also abnormally increase due to the degradation of the interface between Ge and GaAs surface, which was well indicated in electron energy loss spectroscopy, energy dispersive x-ray spectroscopy, and transmission electron microscopy analyses. Results indicate that a thin Ge ICL, optimized conditions for PDA, as well as high-k material (HfO2) play important roles in allowing further EOT scale down and in providing a high-quality interface.
We present n-channel enhancement-mode inversion-type indium phosphide (InP) metal-oxide-semiconductor field-effect transistors with atomic-layer-deposited Al2O3 gate dielectric. It has been found that applying sulfur passivation and postdeposition annealing in the process improves the drive current and subthreshold swing. Transistors on semi-insulating InP substrates show much higher drive current than the ones on p-type InP due to the asymmetric distribution of interface state along the bandgap between InP and Al2O3. The effects of transient and slow traps on the transistor performance have also been investigated using constant electrical stress measurements and pulse measurements.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.