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The electrical characteristics of n-GaN/nitrided-thin-Ga2O3/SiO2 and n-GaN/Si3N4 metal-insulator-semiconductor (MIS) capacitors have been compared, and the work-function difference [lowercase_phi_synonym]ms and effective dielectric-fixed charge density Qf,eff have been determined. Oxide samples showed lower interface trap level density Dit, lower leakage current, and better reproducibility compared to the nitride samples. The superior properties of the oxide samples are partially attributed to the nitrided-thin-Ga2O3 layer (∼0.6-nm-thick). [lowercase_phi_synonym]ms and Qf,eff were determined, respectively, as 0.13 V and 1.0×1012 q cm-2 in oxide and 0.27 V and -3.6×1011 q cm-2 in nitride samples using flatband voltage versus dielectric thickness data. True dielectric-fixed charge density and location of the major amount of fixed charge are discussed based on Qf,eff, Dit, and spontaneous polarization of n-GaN. [ABSTRACT FROM AUTHOR]

In most previous reports on Al-gated n-GaN/SiO2 metal oxide semiconductor (MOS) structures, the work-function difference between A1 and n-GaN (φms) has been chosen as 0 V by assuming that the work function of the A1 gate and n-GaN are both 4.1 eV. In this letter, φms is determined as ∼0.1 V using Al-gated n-GaN/nitrided-thin-Ga203/SiO2 MOS capacitors by measuring flatband voltage as a function of oxide thickness. Formation of an ultrathin (∼0.6-nm-thick) Ga203 layer on n-GaN prior to the deposition of SiO2 is important to prevent uncontrolled parasitic oxidation of the n-GaN surface and possibly reduces the interface dipole between n-GaN and SiO2. [ABSTRACT FROM AUTHOR]

Highlights: [•] A screening of chemical non-ionic surfactants against pathogenic microbial biofilms is proposed. [•] Pluronic F127 presented anti-adhesion characteristics due its conformation on hydrophobic surface. [•] A simple Pluronic F127 coating remains retained at the surface after extensive washes. [•] We report interesting results in the field of biomaterials and hospital infections. [ABSTRACT FROM AUTHOR]

Abstract: Al2O3 was deposited by pulsed DC reactive sputter on Ge(100) aiming at producing layers with reduced OH and H2O content in comparison with water-based atomic layer deposition. In this way, the intrinsic interaction of Al2O3 with Ge could be probed. Photoelectron spectroscopy showed evidence of a GeO2 interlayer in as-deposited samples. Thermal annealing in Ar or forming gas for 30min at 350°C reduced the amount of oxidized Ge, i.e. significant activity took place at the Al2O3/Ge interface irrespective of annealing ambient. The remaining transition layer consisted essentially of aluminum germanates. Analysis of Si companion samples indicates that in the absence of an oxidizing agent, Al2O3/Ge is more stable than Al2O3/Si. [Copyright &y& Elsevier]

There is a growing quest for an ideal biomaterial that shows appropriate cellular response and is not susceptible to microbial adhesion. In this study, commercial grade II titanium was submitted to RF/ DC plasma surface modification at 2.2 mbar, using gas mixtures of argon, nitrogen, and oxygen at proportions 4:1:2 and 4:1:3. The surfaces were physically and chemically characterized. In order to evaluate bacterial response, the surfaces were exposed to S taphylococcus epidermidis. Oxynitrided samples, although having a higher roughness as compared with untreated samples, exhibited lower bacterial growth. This observation is probably due to the formation of different crystalline phases of nitrides and oxides caused by plasma treatment. The surface with highest contact angle and highest surface tension showed lower bacterial adhesion. These results were confirmed by scanning electron microscopy. The role of nitrogen in reducing bacterial adhesion is clear when this material is compared with untreated titanium, on which only an oxide film is present. [ABSTRACT FROM AUTHOR]

We investigated the effects of Al2O3 thickness on the suppression of parasitic substrate oxidation in HfO2–ultrathin-Al2O3–Si structures. The use of H2O as oxidizing agent in the atomic layer deposition (ALD) chemistry is considered key to preventing the formation of an SiOx interlayer during oxide deposition. An Al2O3 layer prepared with 10 cycles of atomic layer deposition (ALD, ∼0.74 nm) effectively suppressed substrate oxidation during rapid thermal annealing in N2 for 10 s below 800 °C. Parasitic oxidation was observed at 600 °C for samples with only five cycles or without Al2O3. Ultrathin Al2O3 films can be relevant for the integration of HfO2 as gate dielectric in silicon technology. [ABSTRACT FROM AUTHOR]