Comparison of fin-edge roughness and metal grain work function variability in InGaAs and Si FinFETs

The fin-edge roughness (FER) and the TiN metal grain work function (MGW)-induced variability affecting OFF and ON device characteristics are studied and compared between a 10.4 nm gate length In0.53Ga0.47As FinFET and a 10.7 nm gate length Si FinFET. We have analyzed the impact of variability by assessing five figures of merit (threshold voltage, subthreshold slope, OFF-current, drain-induced-barrier-lowering, and ON-current) using the two state-of-the-art in-house-build 3-D simulation tools based on the finite-element method. Quantum-corrected 3-D drift-diffusion simulations are employed for variability studies in the subthreshold region while, in the ON-region, we use quantum-corrected 3-D ensemble Monte Carlo simulations. The In0.53Ga0.47As FinFET is more resilient to the FER and MGW variability in the subthreshold compared with the Si FinFET due to a stronger quantum carrier confinement present in the In0.53Ga0.47As channel. However, the ON-current variability is between 1.1 and 2.2 times larger for the In0.53Ga0.47As FinFET than for the Si counterpart, respectively

3-D Finite Element Monte Carlo Simulations of Scaled Si SOI FinFET With Different Cross Sections

Si SOI FinFETs with gate lengths of 12.8 nm and 10.7 nm are modelled using 3D Finite Element Monte Carlo (MC) simulations with 2D Schroedinger equation quantum corrections. These non-planar transistors are studied for two cross-sections: rectangular-like and triangular-like, and for two channel orientations: h100i and h110i. The 10.7 nm gate length rectangular-like FinFET is also simulated using the 3D Non-Equilibrium Green’s Functions (NEGF) technique and the results are compared with MC simulations. The 12.8 nm and 10.7 nm gate length rectangular-like FinFETs give larger drive currents per perimeter by about 25−27% than the triangular-like shaped but are outperformed by the triangular-like ones when normalised by channel area. The devices with a <100> channel orientation deliver a larger drive current by about 11% than their counterparts with a h110i channel when scaled to 12.8 nm and to 10.7 nm gate lengths. ID–VG characteristics at low and high drain biases obtained from the 3D NEGF simulations show a remarkable agreement with the MC results and overestimate the drain current from a gate bias of 0.5 V only due to exclusion of the interface roughness and ionized impurity scatterings

Anisotropic Quantum Corrections for 3-D Finite-Element Monte Carlo Simulations of Nanoscale Multigate Transistors

Anisotropic 2-D Schrödinger equation-based quantum corrections dependent on valley orientation are incorporated into a 3-D finite-element Monte Carlo simulation toolbox. The new toolbox is then applied to simulate nanoscale Si Siliconon-Insulator FinFETs with a gate length of 8.1 nm to study the contributions of conduction valleys to the drive current in various FinFET architectures and channel orientations. The 8.1 nm gate length FinFETs are studied for two cross sections: rectangular-like and triangular-like, and for two channel orientations: 〈100〉 and 〈110〉. We have found that quantum anisotropy effects play the strongest role in the triangular-like 〈100〉 channel device increasing the drain current by ~13% and slightly decreasing the current by 2% in the rectangular-like 〈100〉 channel device. The quantum anisotropy has a negligible effect in any device with the 〈110〉 channel orientation

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

A measurement of the production cross-section for top quark pairs(\ttbar) in $pp$ collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron $e$ or muon $\mu$) with large missing transverse energy and at least four jets, and dilepton ($ee$, $\mu\mu$ or $e\mu$) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be $12.2 \pm 3.9$ events and $2.5 \pm 0.6$ events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurement of the top quark pair cross section with ATLAS in pp collisions at √s=7 TeV using final states with an electron or a muon and a hadronically decaying τ lepton

A measurement of the cross section of top quark pair production in proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 7 TeV is reported. The data sample used corresponds to an integrated luminosity of 2.05 fb -1. Events with an isolated electron or muon and a τ lepton decaying hadronically are used. In addition, a large missing transverse momentum and two or more energetic jets are required. At least one of the jets must be identified as originating from a b quark. The measured cross section, σtt-=186±13(stat.)±20(syst.)±7(lumi.) pb, is in good agreement with the Standard Model prediction

Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of √s=7 TeV proton-proton collisions

Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV

Measurement of the top quark pair production cross-section with ATLAS in the single lepton channel

A measurement of the production cross-section for top quark pairs (t[bar over t]) in pp collisions at √s = 7 TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in the single lepton topology by requiring an electron or muon, large missing transverse momentum and at least three jets. With a data sample of 35 pb[superscript −1], two different multivariate methods, one of which uses b-quark jet identification while the other does not, use kinematic variables to obtain cross-section measurements of σ[subscript t bar over t] = 187 ± 11 (stat.) [+18 over −17] (syst.) ± 6 (lumi.) pb and σ[subscript t bar over t] = 173 ± 17 (stat.) [+18 over −16] (syst.) ±6 (lumi.) pb respectively. The two measurements are in agreement with each other and with QCD calculations. The first measurement has a better a priori sensitivity and constitutes the main result of this Letter.European Organization for Nuclear ResearchUnited States. Dept. of EnergyNational Science Foundation (U.S.)Brookhaven National Laborator

Search for anomalous production of prompt like-sign muon pairs and constraints on physics beyond the standard model with the ATLAS detector

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMAn inclusive search for anomalous production of two prompt, isolated muons with the same electric charge is presented. The search is performed in a data sample corresponding to 1.6 fb-1 of integrated luminosity collected in 2011 at √s = 7 TeV with the ATLAS detector at the LHC. Muon pairs are selected by requiring two isolated muons of the same electric charge with pT > 20 GeV and |η| < 2.5. Minimal requirements are placed on the rest of the event activity. The distribution of the invariant mass of the muon pair m(μμ) is found to agree well with the background expectation. Upper limits on the cross section for anomalous production of two muons with the same electric charge are placed as a function of m(μμ) within a fiducial region defined by the event selection. The fiducial cross-section limit constrains the like-sign top-quark pair-production cross section to be below 3.7 pb at 95% confidence level. The data are also analyzed to search for a narrow like-sign dimuon resonance as predicted for e.g. doubly charged Higgs bosons (H±±). Assuming pair production of H±± bosons and a branching ratio to muons of 100% (33%), this analysis excludes masses below 355 (244) GeV and 251 (209) GeV for H±± bosons coupling to left-handed and right-handed fermions, respectivelyWe acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF, DNSRC and Lundbeck Foundation, Denmark; ARTEMIS, European Union; IN2P3-CNRS, CEA-DSM/IRFU, France; GNAS, Georgia; BMBF, DFG, HGF, MPG and AvH Foundation, Germany; GSRT, Greece; ISF, MINERVA, GIF, DIP and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; RCN, Norway; MNiSW, Poland; GRICES and FCT, Portugal; MERYS (MECTS), Romania; MES of Russia and ROSATOM, Russian Federation; JINR; MSTD, Serbia; MSSR, Slovakia; ARRS and MVZT, Slovenia; DST/NRF, South Africa; MICINN, Spain; SRC and Wallenberg Foundation, Sweden; SER, SNSF and Cantons of Bern and Geneva, Switzerland; NSC, Taiwan; TAEK, Turkey; STFC, the Royal Society and Leverhulme Trust, United Kingdom; DOE and NSF, United States of America. The crucial computing support from all WLCG partners is acknowledged gratefully, in particular, from CERN and the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFNCNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA) and in the Tier-2 facilities worldwid