Improved performance of yttrium-doped Al 2O 3 as inter-poly dielectric for flash-memory applications

Yttrium-doped Al 2O 3Y xAl yO) with different yttrium contents prepared by co-sputtering method is investigated as the inter-poly dielectric (IPD) for flash memory applications. A poor SiO 2-like interlayer formed at the IPD/Si interface is confirmed by X-ray photoelectron spectroscopy, and can be suppressed by Y doping through the transformation of silica into silicate. Compared with Al 2O 3 and Y 2O 3 films, the optimized Y xAl yO film shows lower interface-state density, lower bulk charge-trapping density, higher dielectric constant, and smaller gate leakage, due to the suppressed interlayer and good thermal property ascribed to appropriate Y and Al contents in the film. Therefore, the optimized Y xAl yO film is a promising candidate as the IPD for flash memory. © 2010 IEEE.published_or_final_versio

Improved charge-trapping properties of HfYON film for nonvolatile memory applications in comparison with HfON and Y 2O 3 films

The charge-trapping properties of HfYON film are investigated by using the Al/HfYON/SiO 2/Si structure. The physical features of this film were explored by transmission electron microscopy and x-ray photoelectron spectroscopy. The proposed device shows better charge-trapping characteristics than samples with HfON or Y 2O 3 as the charge-trapping layer due to its higher trapping efficiency, as confirmed by extracting their charge-trap centroid and charge-trap density. Moreover, the Al/Al 2O 3/HfYON/SiO 2/Si structure shows high program speed (4.5 V at 14 V, 1 ms), large memory window (6.0 V at 14 V, 1 s), and good retention property, further demonstrating that HfYON is a promising candidate as the charge-trapping layer for nonvolatile memory applications. © 2011 American Institute of Physics.published_or_final_versio

Nitrided SrTiO 3 as charge-trapping layer for nonvolatile memory applications

Charge-trapping characteristics of SrTiO 3 with and without nitrogen incorporation were investigated based on Al/ Al 2 O 3/SrTiO 3/SiO 2 /Si (MONOS) capacitors. A Ti-silicate interlayer at the SrTiO 3/SiO 2 interface was confirmed by x-ray photoelectron spectroscopy and transmission electron microscopy. Compared with the MONOS capacitor with SrTiO 3 as charge-trapping layer (CTL), the one with nitrided SrTiO 3 showed a larger memory window (8.4 V at ±10 V sweeping voltage), higher P/E speeds (1.8 V at 1 ms +8 V) and better retention properties (charge loss of 38% after 10 4s), due to the nitrided SrTiO 3 film exhibiting higher dielectric constant, higher deep-level traps induced by nitrogen incorporation, and suppressed formation of Ti silicate between the CTL and SiO 2 by nitrogen passivation. © 2011 American Institute of Physics.published_or_final_versio

Improved performance by using TaON/SiO2 as dual tunnel layer in Charge-Trapping nonvolatile memory

postprin

A novel MONOS memory with high-κ HfLaON as charge-storage layer

MIS capacitors with a high-κ HfLaON or HfLaO gate dielectric are fabricated by using a reactive sputtering method to investigate the applicability of the films as a novel charge-storage layer in a metaloxidenitrideoxidesilicon nonvolatile memory device. Experimental results indicate that the MIS capacitor with a HfLaON gate dielectric exhibits a large memory window, high program/erase speed, excellent endurance property, and reasonable retention. The involved mechanisms for these promising characteristics with HfLaON are thought to be in part from nitrogen incorporation leading to higher density of traps with deeper levels and, thus, higher trapping efficiency, stronger HfN and LaN bonds, and more stable atomic structure and HfLaONSiO 2 interface, as compared to the HfLaO dielectric. © 2011 IEEE.published_or_final_versio

Enhancement of defense responses by oligandrin against Botrytis cinerea

Oligandrin is an elicitin-like protein with a molecular mass of ∼10 kDa secreted by Pythium oligandrum. Here, the effect of oligandrin on defense response against Botrytis cinerea in tomato leaves is reported. Tomato seedlings were pretreated with 5 ml oligandrin (10 g/ml) by root submerging and then inoculated with B. cinerea. Disease severity was subsequently evaluated and compared with the control. Results indicate that oligandrin pretreatment reduced disease index by 78.6% on day 7 after inoculation. On day 3 after inoculation, oligandrin pretreatment caused up-regulation of peroxidases (POD), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) in leaves by 20.0, 5.56 and 32.88%, compared with inoculation without oligandrin pretreatment, respectively. On day 5 after inoculation, POD, PPO and PAL were up-regulated by 46.24, 32.61 and 57.14%, respectively. 24 h after the treatment with oligandrin, the expression of pathogenesis-related protein (PRs) genes, PR-2a (extracellular β-1,3-glucanase) and PR-3a (extracellular chitinase), were up-regulated by 7.75 fold and 4.56 fold in tomato leaves, compared with the control, respectively. The expression of LeERF2, a member of ethylene-dependent signaling pathway, was also significantly elevated by 7.41 fold. At the same time, the expression of ethylene receptor homologue PR-6 protein was also induced. These results indicate that oligandrin can induce resistance to B. cinerea in tomatoes, and the induction of resistance involves the activation of the ethylene-dependent signaling pathway. Oligandrin is potentially useful for gray mould prevention in tomato crop.Key words: Botrytis cinerea, induced resistance, oligandrin, resistance related enzymes

Compressibility effects on the scalar mixing in reacting homogeneous turbulence

The compressibility and heat of reaction influence on the scalar mixing in decaying isotropic turbulence and homogeneous shear flow are examined via data generated by direct numerical simulations (DNS). The reaction is modeled as one-step, exothermic, irreversible and Arrhenius type. For the shear flow simulations, the scalar dissipation rate, as well as the time scale ratio of mechanical to scalar dissipation, are affected by compressibility and reaction. This effect is explained by considering the transport equation for the normalized mixture fraction gradient variance and the relative orientation between the mixture fraction gradient and the eigenvectors of the solenoidal strain rate tensor.Comment: In Turbulent Mixing and Combustion, eds. A. Pollard and S. Candel, Kluwer, 200

Thermally induced conduction type conversion in n-type InP

n-type semiconducting InP is changed into p-type semiconducting by short time annealing at 700 °C. Further annealing for a longer time leads to a second conduction-type conversion changing the material back to n type again but with a much higher resistivity. These conduction conversions indicate the formation of both acceptor and donor defects and the progressive variation of their relative concentrations during annealing. © 1999 American Institute of Physics.published_or_final_versio

The depth-profiled carrier concentration and scattering mechanism in undoped GaN film grown on sapphire

The carrier concentration and scattering mechanism in undoped GaN film grown on sapphire were investigated. The film was grown on sapphire using metal organic chemical vapor deposition (MOCVD). Confocal micro-Raman spectroscopic measurements and temperature-dependant Hall (TDH) measurements were performed for the study of the depth distribution of the carrier density across the GaN film. The existence of a nonuniform spatial distribution of free carriers in the film with a highly conductive layer of ∼1 μm thickness near the GaN sapphire boundary was confirmed from the study. The electron mobility limiting effect of nitrogen vacancies on GaN bulk film was also discussed.published_or_final_versio

A Simple Method to Synthesize Cadmium Hydroxide Nanobelts

Cd(OH)2nanobelts have been synthesized in high yield by a convenient polyol method for the first time. XRD, XPS, FESEM, and TEM were used to characterize the product, which revealed that the product consisted of belt-like crystals about 40 nm in thickness and length up to several hundreds of micrometers. Studies found that the viscosity of the solvent has important influence on the morphology of the final products. The optical absorption spectrum indicates that the Cd(OH)2nanobelts have a direct band gap of 4.45 eV