Charge trapping properties of N2O-treated NH3-nitrided oxides under high-field stress

Conference Theme: Asia-Pacific Microelectronics 2000A new technique, namely N2O treatment of NH3-nitrided oxides (NON20), is proposed to fabricate thin oxide. It is shown that the N2O treatment is superior to conventional reoxidation step in improving charge trapping property and interface hardness of oxides under high-field stresspublished_or_final_versio

Off-state gate leakage current in N-channel MOSFETs with gate dielectrics prepared by different techniques

The off-state gate current of n-channel MOSFETs with OX, RONO, N20N, and N20G oxides as gate dielectrics was investigated in this work. It is revealed that gate current conduction mechanism in the low field region is very different for these oxides. Enhanced conductivity is observed in RONO and N20G oxides, which is attributed to the trap-assisted tunneling mechanism. Therefore, in view of gate leakage, the method of nitridizing pre-grown thermal oxide is more feasible than directly growing oxide in N2O ambient, especially in leakage sensitive applications, such as very-low-power battery-based circuits, DRAM cells, etc.published_or_final_versio

Off-state leakage current in N-channel MOSFETs with gate dielectrics prepared by different techniques

This journal vol. entitled: Insulating Films on Semiconductors, Villard-de-Lans, France, 7–10 June 1995Off-state gate current of n-channel MOSFET's with OX, RONO, N2ON, and N2OG oxides as gate dielectrics was investigated in this work. It is revealed that gate current conduction mechanism in low field region is very different for these oxides. Enhanced conductivity is observed in RONO and N2OG oxides, which is attributed to the trap-assisted tunneling mechanism. Therefore, the method of nitridizing pre-grown thermal oxide (N2ON) is more feasible than directly growing oxide in N2O ambient (N2OG) in view of gate current leakage, especially in leakage-sensitive applications, such as very-low-power battery-based circuits, DRAM cells ...postprin

A novel technique of N2O-treatment on NH3-nitrided oxide as gate dielectric for nMOS transistors

A novel technique of N2O treatment on NH3-nitrided oxide is used to prepare thin gate oxide. Experiments on MOS capacitors and nMOSFET's with this kind of gate dielectric show that N2O treatment is superior to conventional reoxidation step in suppressing both electron and hole trappings and interface trap creation under high-field stress. Interface hardness against hot-carrier bombardment and neutral electron trap generation are also improved. Thus, N2O treatment on NH3 -nitrided oxide shows excellent electrical and reliability properties, while maintaining sufficiently high nitrogen concentration in gate oxide which offers good resistance to dopant penetration.published_or_final_versio

Mobility improvement of n-MOSFET's with nitrided gate oxide by backsurface Ar+ bombardment

Low-energy (550 eV) argon-ion beam was used to bombard directly, the backsurface of nitrided n-MOSFET's after the completion of all conventional nMOS processing steps. The interface characteristics and inversion layer mobility of the MOS devices were investigated. The results show that, as bombardment time increases, interface state density and fixed charge density decrease first, and then the change slows down or even turns around. Correspondingly, the carrier mobility and drain conductance of the MOS devices are found to enhance first, and then saturate or turn around. Therefore, this simple technique, which is readily compatible with existing IC processing, is effective for restoring some of the lost device performance associated with gate-oxide nitridation.published_or_final_versio

AC hot-carrier-induced degradation in NMOSFET's with N 2O-based gate dielectrics

Frequency-dependent ac-stress-induced degradation in NMOSFET's with N 2O-grown and N 2O-nitrided gate oxides was investigated. Suppressed device degradation is observed in both N 2O-based devices as compared to SiO 2 device for frequency up to 100 kHz, which is attributed to nitrogen incorporation in the gate oxides. Moreover, when comparing the two N 2O-based oxides, N 2O-grown oxide device exhibits enhanced degradation than N 2O-nitrided oxide device. Charge pumping measurements reveal that N 2O-nitrided oxide has better immunity to interface-state and neutral-electron-trap generation under dynamic stress.published_or_final_versio

Sigma-2 receptor ligand as a novel method for delivering a SMAC mimetic drug for treating ovarian cancer

BACKGROUND: The sigma-2 receptor has been validated as a biomarker for proliferating tumours. Second mitochondria-derived activator of caspase (Smac) is a protein released from mitochondria into the cytosol, leading to apoptosis. In this study, we investigated a sigma-2 ligand as a tumour-targeting drug delivery agent for treating ovarian cancer. METHODS: A sigma-2 ligand, SW 43, was conjugated with a Smac mimetic compound (SMC), SW IV-52s, to form SW III-123. The delivery function of the sigma-2 moiety and cell killing mechanisms of SW III-123 were examined in human ovarian cancer cell lines. RESULTS: SW III-123 internalisation into ovarian cancer cells was mediated by sigma-2 receptors. SW III-123, but not SW IV-52s or SW 43, exhibited potent cytotoxicity in human ovarian cancer cell lines SKOV-3, CaOV-3 and BG-1 after 24-h treatment, suggesting that the sigma-2 ligand successfully delivered SMC into ovarian cancer cells. SW III-123 induced rapid degradation of inhibitor of apoptosis proteins (cIAP1 and cIAP2), accumulation of NF-κB-inducing kinase (NIK) and phosphorylation of NF-κB p65, suggesting that SW III-123 activated both canonical and noncanonical NF-κB pathways in SKOV-3 cells. SW III-123 cleaved caspase-8, -9 and -3. Tumour necrosis factor alpha (TNFα) antibody markedly blocked SW III-123-induced cell death and caspase-3 activity in SKOV-3 cells, indicating that SW III-123 activated both intrinsic and extrinsic apoptotic pathways and induced TNFα-dependent cell death in SKOV-3 cells. CONCLUSION: Sigma-2 ligands are a promising tumour-targeting drug delivery agent. Sigma-2-conjugated SMC exemplifies a novel class of therapeutic drugs for treating ovarian cancer

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Microglia activation in a model of retinal degeneration and TUDCA neuroprotective effects

Background: Retinitis pigmentosa is a heterogeneous group of inherited neurodegenerative retinal disorders characterized by a progressive peripheral vision loss and night vision difficulties, subsequently leading to central vision impairment. Chronic microglia activation is associated with various neurodegenerative diseases including retinitis pigmentosa. The objective of this study was to quantify microglia activation in the retina of P23H rats, an animal model of retinitis pigmentosa, and to evaluate the therapeutic effects of TUDCA (tauroursodeoxycholic acid), which has been described as a neuroprotective compound. Methods: For this study, homozygous P23H line 3 and Sprague-Dawley (SD) rats were injected weekly with TUDCA (500 mg/kg, ip) or vehicle (saline) from 20 days to 4 months old. Vertical retinal sections and whole-mount retinas were immunostained for specific markers of microglial cells (anti-CD11b, anti-Iba1 and anti-MHC-II). Microglial cell morphology was analyzed and the number of retinal microglial was quantified. Results: Microglial cells in the SD rat retinas were arranged in regular mosaics homogenously distributed within the plexiform and ganglion cell layers. In the P23H rat retina, microglial cells increased in number in all layers compared with control SD rat retinas, preserving the regular mosaic distribution. In addition, a large number of amoeboid CD11b-positive cells were observed in the P23H rat retina, even in the subretinal space. Retinas of TUDCA-treated P23H animals exhibited lower microglial cell number in all layers and absence of microglial cells in the subretinal space. Conclusions: These results report novel TUDCA anti-inflammatory actions, with potential therapeutic implications for neurodegenerative diseases, including retinitis pigmentosa.This research was supported by grants from the Spanish Ministry of Economy and Competitiveness-FEDER (BFU2012-36845), Instituto de Salud Carlos III (RETICS RD12/0034/0010), Organización Nacional de Ciegos Españoles (ONCE), FUNDALUCE, Asociación Retina Asturias and Fundación Jesús de Gangoiti

Lumazine Synthase Protein Nanoparticle-Gd(III)-DOTA Conjugate as a T1 contrast agent for high-field MRI

With the applications of magnetic resonance imaging (MRI) at higher magnetic fields increasing, there is demand for MRI contrast agents with improved relaxivity at higher magnetic fields. Macromolecule-based contrast agents, such as protein-based ones, are known to yield significantly higher r(1) relaxivity at low fields, but tend to lose this merit when used as T-1 contrast agents (r(1)/r(2) = 0.5 similar to 1), with their r(1) decreasing and r(2) increasing as magnetic field strength increases. Here, we developed and characterized an in vivo applicable magnetic resonance (MR) positive contrast agent by conjugating Gd(III)-chelating agent complexes to lumazine synthase isolated from Aquifex aeolicus (AaLS). The r(1) relaxivity of Gd(III)-DOTA-AaLS-R108C was 16.49 mM(-1)s(-1) and its r(1)/r(2) ratio was 0.52 at the magnetic field strength of 7 T. The results of 3D MR angiography demonstrated the feasibility of vasculature imaging within 2 h of intravenous injection of the agent and a significant reduction in T-1 values were observed in the tumor region 7 h post-injection in the SCC-7 flank tumor model. Our findings suggest that Gd(III)-DOTA-AaLS-R108C could serve as a potential theranostic nanoplatform at high magnetic field strength.open0