We have demonstrated wide-range modulation of Schottky barrier height (SBH) of NiGe∕Ge(100) interfaces by using a valence mending adsorbate, sulfur, segregation during Ni germanidation. Implanted sulfur atoms, segregated during Ni germanidation, are expected to act as dangling bond terminator at the NiGe∕Ge interface. The experimental results show that the strong Fermi level pinning feature of NiGe∕Ge interfaces was alleviated, and SBH of NiGe∕n-Ge(100) gradually decreased from 0.61to0.15eV with an increase in the implanted sulfur dose. This method opens a way to realize Ge channel complementary metal-oxide-semiconductor field-effect transistors with metal source/drain.
The impact of Si passivation (SP) on Ge metal-insulator-semiconductor interface properties and the inversion-layer mobility of Ge p-type metal-insulator-semiconductor field effect transistors (PMISFETs) were investigated by using the devices with different thicknesses of the SP layers. SP was effective in decreasing the total charged centers instead of the interface traps. As a result, the inversion-layer hole mobility of the Ge MISFET was significantly improved by introducing the SP layers of the appropriate thickness. This improvement is attributable to the reduction of the amount of the interface charges and the separation of the positions of mobile carriers and the interface charges by the SP layers.
Instantaneous flow structures "within" a cubical canopy are investigated via large-eddy simulation. The main topics of interest are, (1) large-scale coherent flow structures within a cubical canopy, (2) how the structures are coupled with the turbulent organized structures (TOS) above them, and (3) the classification and quantification of representative instantaneous flow patterns within a street canyon in relation to the coherent structures. We use a large numerical domain (2,560 m × 2,560 m × 1,710 m) with a fine spatial resolution (2.5 m), thereby simulating a complete daytime atmospheric boundary layer (ABL), as well as explicitly resolving a regular array of cubes (40 m in height) at the surface. A typical urban ABL is numerically modelled. In this situation, the constant heat supply from roof and floor surfaces sustains a convective mixed layer as a whole, but strong wind shear near the canopy top maintains the surface layer nearly neutral. The results reveal large coherent structures in both the velocity and temperature fields "within" the canopy layer. These structures are much larger than the cubes, and their shapes and locations are shown to be closely related to the TOS above them. We classify the instantaneous flow patterns in a cavity, specifically focusing on two characteristic flow patterns: flushing and cavity-eddy events. Flushing indicates a strong upward motion, while a cavity eddy is characterized by a dominant vortical motion within a single cavity. Flushing is clearly correlated with the TOS above, occurring frequently beneath low-momentum streaks. The instantaneous momentum and heat transport within and above a cavity due to flushing and cavity-eddy events are also quantified.
We fabricated non-recessed-gate enhancement-mode (E-mode) AlGaN/GaN high electron mobility transistors (HEMTs) with a gate length L
g of 120 nm. As gate metals, Ni/Pt/Au and Mo/Pt/Au were used. The Ni/Pt/Au-gate HEMTs with rapid thermal annealing (RTA) at 500°C were normally-off at a gate-source voltage V
gs of 0 V, indicating E-mode operation. Moreover, the Mo/Pt/Au-gate HEMTs also showed E-mode device operation without RTA. The fabricated E-mode HEMTs with both gate metals showed high RF performance. We obtained a cutoff frequency f
T of more than 50 GHz and a maximum oscillation frequency f
max of approximately 100 GHz.
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.