bluuebunny/crossref_metadata_2025_split huggingface dataset:
The study of DNA nanofibers
Authors: Singh Mahi R. 
Published: April 2011

AbstractWe study the acousto-optic effect on the polaritonic properties of DNA nanofibers which are fabricated by embedding a DNA wire into a polaritonic material. This is a new research area and can be called nanobiopolaritonics. Polaritonic materials have energy gaps in their dispersion relation due to the coupling between optical photons and photons. The bound states of DNA wire are calculated using transfer matrix method. It is found that some of the bound states of the DNA wire lie within the band gap of the polaritonic material. These states do not decay into the polaritonic material since there are not states available for decay process to occur. This means DNA nanofibers has an extremely high Q factor. We have also studied the acousto-optic effect on the photon absorption in DNA nanofibers doped with ensemble of quantum dots. The quantum dots interact with the DNA wire via electron bound polaritons interaction. We have discovered a switching mechanism in DNA nanofibers. When the resonance energy of the quantum dots lies near bound polaritons states, the system becomes transmitting for frequency of a probe field due to the strong electron bound polaritons interaction. This is can be assigned as ‘ON’ of the switch. However, when the strain field is applied the DNA fiber can now absorb the probe beam. This is can be assigned as ‘OFF’ of the switch.
Direct Heteroepitaxial Growth of ZnTe(100) and CdZnTe(100)/ZnTe(100) on Si(100) Substrates by MBE
Authors: Lyon T. J. de , Johnson S. M. , Cockrum C. A. , Wu O. K. , Roth J. A. 
Published: April 2011

AbstractEpitaxial films of ZnTe(100) and CdZnTe(100)/ZnTe(100) have been deposited by molecular-beam epitaxy onto Si(100) substrates misoriented from 0–8 degrees towards the [011] direction. The films were characterized with x ray diffraction, photoluminescence spectroscopy, optical microscopy, and stylus profilometry. Through use of ZnTe buffer layers, single crystal CdZnTe(100) films have been demonstrated on both 4° and 8° misoriented Si with structural quality comparable to that obtained with GaAs/Si composite substrates. X ray rocking curves for ZnTe(400) with FWHM less than 300 arcseconds and for CdZnTe(400) with FWHM less than 160 arcseconds have been obtained for as-grown films. The observed surface morphologies are superior to those obtained on GaAs/Si composite substrates. HgCdTe(100) films with x ray FWHM as low as 55 arcseconds and average etch pit densities of 5 × 106 cm−2 have been deposited by liquid phase epitaxy on these MBE CdZnTe/ZnTe/Si substrates.
Crystallographic and Metallurgical Characterization of Radiation Detector Grade Cadmium Telluride Materials
Authors: Johnson C.J. , Eissler E.E. , Cameron S.E. , Kong Y. , Fan S. , Jovanovic S. , Lynn K.G. 
Published: April 2011

AbstractRadiation detector grade CdTe crystals are characterized by several crystallographic and metallurgical techniques including infrared microscopy, dislocation etch pitting and X-ray diffraction. Results are presented for 50 detectors fabricated from an ingot produced by the high pressure Bridgman method. Data on the temperature dependence of leakage current and pulse height analysis are presented, along with measurements of room temperature charge transport properties. Attempts to relate crystal structure to detector performance will be discussed.
Performance Characteristics of CDTE Gamma-Ray Spectrometers
Authors: Squillante Michael R. , Cole Herbert , Waer Peter , Entine Gerald 
Published: April 2011

AbstractThe use of cadmium telluride (CdTe) semiconductor nuclear detectors is continuing to expand into new areas because of their unique properties which include room temperature operation and high detection efficiency. In addition, they remain the material of choice in many critical applications such as nuclear medicine and power plant monitoring because of their reputation for reliability and long term stability1. CdTe is by far the most developed of the compound semiconductors used in nuclear detector applications and it offers a number of significant benefits to researchers, clinicians and engineers who have special requirements relating to size, sensitivity and operating temperature.Recently, there have been improvements in the growth of the crystalline material and in the fabrication procedures which have resulted in better performance and in the ability to produce arrays. This article describes the physical and electronic properties of CdTe nuclear detectors, discusses how the crystal growth and device fabrication procedures can affect these properties, and compares the performance to CdZnTe detectors.
Thermal Stability of Ir-Silicide/SiGe Layers Grown in a Dual Electron Gun Chamber at Ultra-High Vacuum (Extended Abstract)
Authors: Chung C. K. , Hwang J. 
Published: April 2011

AbstractHeteroepitaxial Ir-silicide/SiGe layers on the top of p-Si(100) have been achieved at a substrate temperature of 450 °C. The co-deposited Ir-silicide layer was determined to be Ir3Si4 with four types of epitaxial modes. Thermal stability of the film was examined by using Auger electron spectroscopy and X-ray diffractometer. The Ir3Si4/SiGe layers were stable as annealed at 550 °C for 20 sec in a rapid thermal annealing furnace, while interdiffusion between Ir3Si4 and SiGe occurs at a temperature of 750 deg;C or higher for 20 sec. The traditional guard-ring fabrication process should be performed before epitaxial films deposition due to this thermal instability.
Influence of Oxygen on the Iridium Silicide Formation by Rapid Thermal Annealing
Authors: Fernandez M. , Rodriguez T. , Almendra A. , Jimenez-Leube J. , Wolters H. 
Published: April 2011

AbstractIridium silicide formation by rapid thermal annealing (RTA) in an Ar atmosphere or under vacuum has been investigated. The evolution of the silicide front and the identification of the phases were monitored by Auger Electron Spectroscopy (AES) and Rutherford Backscattering Spectrometry (RBS). Oxygen was incorporated during the RTA process in an Ar atmosphere. The oxygen effect is to slow down the silicide formation and eventually to stop it. In all the cases, the oxygen piled-up at the iridium-iridium silicide interface. No distinguishable phase was formed by RTA in an Ar atmosphere. No oxygen contarsi'nation was detected when the RTA was performed under a vacuum lower than 2×10−5 Torr. In this case Ir1Si1 and Ir1Si1.75 phases were formed.
The Staebler-Wronski Effect and the Thermal Equilibration of Defect and Carrier Concentrations
Authors: Dawson R.M.A. , Fortmann C.M. , Li Y.M. , Wronski C.R. 
Published: April 2011

ABSTRACTLight induced degradation of intrinsic Amorphous silicon (a-Si:H) is investigated as a function of temperature. Previous work described an equilibrium framework for the high temperature behavior of dangling bonds defects (DB) 11]; and the temperature dependence of the annealed state photo, σPH, and dark, σD, conductivities of a series of intrinsic a-Si:H Materials deposited over a range of substrate temperatures, 200°C < Ts < 380°C [2]. These results are extended to the light degraded state where elevated temperatures provide for equilibration of the free carrier and DB concentrations. For the equilibrium, light degraded state, both σD and σPH, decrease compared to the annealed state while the ratio, σD/σPH remains unchanged. Relationships between the ratio [DB+]/[DB] and the Fermi level are derived from the equilibrium framework.
Recovery Process for Light-Soaked A-Si:H
Authors: Zhang Qing , Takashima Hideki , Zhou Jiang-Huai , Kumeda Minoru , Shimizu Tatsuo 
Published: April 2011

ABSTRACTWe have found that a broad distribution of the annealing activation energies is necessary to interpret the annealing behavior for the density of metastable defects created by 77K light soaking, while a narrow distribution is sufficient for describing the annealing behavior for the density of those created by RT light soaking. We have also found that the recovery of the degraded photoconductivity is easier than the annealing of the photocreated defects for both 77K and RT light soaking and that, at a given defect density, 77K light soaking degrades the photoconductivity more than RT light soaking. Our results suggest that the photocreated defects with a smaller annealing activation energy are more effective recombination centers than those with a larger annealing activation energy.
The Mobility Lifetime Product of Electrons as a Function of Temperature and Electron Concentrations in a-Si:H
Authors: Nishida Shinichi , Fritzsche Hellmut 
Published: April 2011

ABSTRACTThe photo-field effect has been measured between 4.2K and 300K using an a-Si thin film transistor. The data are fit self-consistently taking full account of changes in space charge, photo carrier drift, diffusion and recombination. Gap state density and capture cross sections are fitting parameters. Evidence for tunnel recombination is found. Electron localization radius was found to be 13Å.
Thermal Modulated Esr For The Study Of Defects In a-SiC:H Films
Authors: Demichelis F. , Giorgis F. , Pirri C. F. , Tresso E. , Ravera L. , Rigato V. 
Published: April 2011

ABSTRACTIn this work we present Thermal Modulation Electron Spin Resonance Measurements performed on a-SiC:H films prepared by Plasma Enhanced Chemical Vapour Deposition with energy gap in the range 1.8–2.5 eV. The results have been compared with previously obtained photothermal and photoconductive ones and have been interpreted by means of a defect distribution which takes into account both silicon based and carbon based defects.
Thermal CVD of Amorphous Germanium Films From 2, 5-Bis (Tert.-Butyl) -2, 5-Diaza-l-Germa-Cyclopentane Organometallic Precursor
Authors: Glatz F. , prokop J. , Vepřek S. , Klingan F.R. , Herrmann W.A. 
Published: April 2011

ABSTRACTA novel organometallic germylene precursor has been synthesized and used for the deposition of amorphous germanium by thermal OM CVD at temperatures below 300°C. The films are of high purity with an oxygen content below the present detection limit of about < 1018 cm−3. Preliminary results on the electronic properties are reported.
Silicon Oxycarbide Microcrystalline Layers Produced by Spatial Separation Techniques
Authors: Martins R. , Ferreira I. , Fortunato E. , Vieira M. 
Published: April 2011

ABSTRACTSilicon oxycarbide microcrystalline layers, n- and p-doped, highly conductive and highly transparent have been produced using a Two Consecutive Decomposition and Deposition Chamber (TCDDC) system. The films exhibit suitable properties for optoelectronic applications where wide band gap materials with required conductivity and stability are needed. In this paper we present the role of partial oxygen pressure (po2) in controlling the composition, structure and transport properties (conductivity, σd and optical gap, Eop) of silicon oxycarbide microcrystalline layers.
Effects of Top Insulator Overlap on the Stability in Hydrogenated Amorphous Silicon Thin Film Transistors
Authors: Choi H.S. , Kim Y.S. , Lee S.K. , Yoon J.K. , Park W.S. , Han Andm. K. 
Published: April 2011

ABSTRACTThe effects of top-insulator on the instability problems of hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFTs) have been studied. In a-Si:H TFT with top-insulator (E/S type), charge trapping into the both of top-insulator and gate insulator has been shown under the bias stress.In order to investigate the charge trapping effects of top-insulator, we proposed a new method of Measurement. By this Method, we observed that trapped charges in top-insulator increased drain currents for positive gate bias stress, and this increment of drain currents was more serious with increasing the ratio of source/drain overlap length to channel length. It has founded that the instability problems of a-Si:H TFTs was attributed to the effects of top-insulator as well as that of gate insulator.
Determination of the Defect Redistribution and Charge Injection Contributions to the a-Si:H Thin-Film Transistor Instability
Authors: Carluccio R. , Pecora A. , Massimiani D. , Fortunato G. 
Published: April 2011

ABSTRACTThe effects of bias-stressing n- and p-channel thin-film transistors, employing thermal silicon dioxide as gate insulator, have been analysed by using different techniques, including field-effect, space-charge photomodulation and photo-induced discharge. Photo-induced discharge experiments have pointed out as parasitic resistance effects can be present in p-channel devices. In order to reduce this problem, thin active layer p-channel devices have been fabricated and, combining these results to those relative to the n-channel transistors, we deduced a predominance of charge injection at low and moderate stress-biases while at high-stress biases modifications in the density of states take place.
Planarization Ability of Chemical Mechanical Planarization (Cmp) Processes
Authors: Stell Matt , Jairath Rahul , Desai Mukesh , Tolles Robert 
Published: April 2011

ABSTRACTMethods for determining planarization ability of CMP were explored. Options included film thickness measurements of the dielectric over metal and field, TIR measurements using profilometry, and a combination of the two. The attempt to observe the in situ change in the topography was addressed in two distinct experimental approaches. The first approach involved processing wafers for predetermined intervals. The other approach processed different wafers for different amounts of time. The effects of down force and platen rpm on planarization ability were studied using the first approach. Results indicate that planarization is more efficient at higher down forces and higher platen rpm. Slurry property effects were examined using the second method. The planarization ability appears to suffer at elevated pH values. This is attributed to both the enhanced solubility of the silica particles and the dielectric itself.
Effectiveness of Nitride Diffusion Barriers in a Self-Encapsulated Copper-Based Metallization.
Authors: Adams D. , Spreitzer R.L. , Russell S.W. , Theodore N.D. , Alford T.L. , Mayer J.W. 
Published: April 2011

ABSTRACTCu(Ti 27 at. %) and Cu(Cr 26 at. %) codeposited on silicon dioxide substrates were annealed in a flowing NH3 ambient at 400 - 600°C for 30 min. The Ti segregates to both the surface to form a TiN(O) layer and to the alloy/SiO2 interface to form a Ti-oxide/Ti-silicide bilayer. The Cr seems to migrate only to the free surface to form a CrNx layer. A 45 nm - thick Al film was deposited after nitridation, whereupon a second anneal was performed to evaluate these nitride layers as diffusion barriers. It was found that the Ti-nitride was stable up to 500°C as compared to Cr-nitride at 600°C.
Coherent TiN Diffusion Barriers for Sub-0.5 μm Planarized AL Technology
Authors: Ngan Ken , Mosely Rod , Xu Zheng , Raaijmakers Ivo 
Published: April 2011

ABSTRACTThis paper describes in situ post deposition treatment technologies to fortify the coherent PVD TiN barrier so that it will withstand the high temperature (> 450°C) Al deposition or flow process for sub-0.5 μm planarized Al technology. The coherent PVD TiN barriers were sputtered under 3 different pressure conditions and subsequently heat treated for fortification. Such heat treated, fortified PVD TiN barriers exhibit low reactivity with Al, which is illustrated by the minimal sheet resistance increase in TiN/Al thin film stacks during the heat treatment. Furthermore, optical and SEM inspection on the silicon surface show no pitting.Leakage current of less than 50 pA has been obtained on 10K-contact chains of sub-0.5 (μm devices using a vacuum integrated coherent Ti/fortified PVD TiN/planarized Al process. This development has led to a completely vacuum integrated sub-0.5 μm PVD Al plug fill process.
The In-Based Metal Ohmic Contacts to n-GaAs
Authors: Ding Sun-An , Fan Tiwen , Xu Zhenjia , Hsu C. C. 
Published: April 2011

ABSTRACTElectrical, structural and reaction characteristics of In-based ohmic contacts to n-GaAs was studied. Attempts were made to form a low band gap interfacial phase of InGaAs to reduce the barrier height at the metal/semiconductor junction and thus yielding a low resistance, high reliability contacts. The contacts were fabricated by e-beam sputtering Ni, NiIn and Ge targets on VPE grown n+-GaAs film (∼1μm, 2xl018 cm-3) in UHV as the structure of Ni(200Å)/NiIn ( 100Å)/Ge(40Å)/n+-GaAs/SI-GaAs, followed by rapid thermal annealing at various temperatures (500-900 °C). The lowest specific contact resistivity (pc) of (1.5±0.5)xl0-6 Qcm2 measured by transmission line method (TLM) was obtained after annealing at 700 °C for 10s. Auger sputtering depth profile and transmission electron microscopy (TEM) were used to analysis the interfacial microstructure. By correlating the interfacial microstructure to the electronical properties, InxGa1-xAs phases with large fractional 'area grown epitaxilly on the GaAs were found to be essential for reduction of the contact resistance.
Electrical Properties of AuZnCr Multilayer Metallizations to InP
Authors: clausen Thomas , leistiko Otto 
Published: April 2011

ABSTRACTThe electrical properties of a Au/Cr/(Au)/Zn/Au (50/25/(50)/100/2 nm) multilayer metallization to n- and p-type InP have been investigated. The results consistently show that it is possible to modulate the effective Schottky barrier height of the metal-semiconductor contact over a large range of values extending from ∼0 eV for contacts to p-type InP to values close to the bandgap of the InP (∼1.3 eV) for contacts to n-type InP. The limiting factor in the developement of the highest quality metal-semiconductor diodes to n-type InP with very high Schottky barrier heights is found to be diffusion of Au elements at high annealing temperatures above 500°C, as determined from I-V, C-V and DLTS plots.
The Reliability of Multilevel Metallization on InGaAs/GaAs Layers
Authors: Chang Edward Y. , Chen J.S. , Wu J.W. , Lin K.C. 
Published: April 2011

ABSTRACTNon-alloyed ohmic contacts using Ti/Pt/Au and Ni/Ge/Au on InGaAs/GaAs layers grown by Molecular Beam Epitaxy (MBE) have been investigated. The n-type InGaAs film has a doping concentration higher than 1X1019 cm-3. Specific contact resistance below 2X10-7 Ωcm2 could be easily achieved with Ti/Pt/Au. Due to the layer intermixing and outdiffusion of In and Ga, the specific contact resistance and sheet resistance increase after thermal treatment. When Ni/Ge/Au is used as the contact metal, the outdiffusion of In and Ga atoms is more severe than that of Ti/Pt/Au. After annealing at 450°C for two minutes, the Au4In formed and the characteristics of the contact became worse. All the phenomena illustrated above have been observed and investigated by Transmission Line Model, X-ray diffraction, Auger Electron Spectroscopy and Secondary Ion Mass Spectrum. As far as the thermal stability is concerned, it is convinced that Ti/Pt/Au is the best one of these two non-alloyed ohmic contact studied.
Characterization of Tungsten Nucleation Layers Deposited Using Various Sih4 and Wf6 Flows
Authors: Rana V.V.S. , Eizenberg M. , Ghanayem S. , Roberts J. , Sinha A.K. 
Published: April 2011

ABSTRACTChemical vapor deposition (CVD) of tungsten nucleation films is typically done using silane (SiH4) reduction of tungsten hexafluoride (WF6). For SiH4/WF6 flow ratios of ≤ 1, pure tungsten of bulk density and resistivity is deposited. Upon increasing the ratio to 2, nearly 40 at.% Si is incorporated in tungsten films. At a ratio of 3, hexagonal WSi2 is deposited, and at ratios of > 6 WSi2 along with silicon is deposited. A maximum in deposition rate is obtained for WSi2 at the ratio of 3, and the deposition rate drops as more silicon is being deposited. The step coverage of films drops dramatically as one moves away from pure W films. The deposition of these films takes place without any incubation time.
Multi-Technique Characterization of WSix films
Authors: Baumann S.M. , Hitzman C.J. , Ivanov I.C. , Craig AY. , Lindley P.M. 
Published: April 2011

ABSTRACTWSix films are used extensively for contact, interconnect, and, in some cases, diffusion and Schottky barriers in semiconductor devices1. The electrical and barrier properties of these films are affected by a variety of factors, such as film stoichiometry, morphology, impurities, etc. This paper will address the capabilities and limitations of a variety of techniques which are frequently used to characterize WSix films. Techniques which were studied include: Dynamic and Static Secondary Ion Mass Spectrometry (SIMS), Rutherford Backscattering Spectrometry and Elastic Recoil Detection (RBS/ERD), Auger Electron Spectroscopy (AES), Field Emission Scanning Electron Microscopy (FE-SEM), Total Reflection X-ray Fluorescence (TXRF), Atomic Force Microscopy (AFM), and X-Ray Photoelectron Spectroscopy (XPS). Film characteristics which were studied included surface morphology; grain structure; film stoichiometry; surface and interface oxide thickness and composition; and surface, bulk, and interface impurity concentrations including metallic, atmospheric, and dopant impurities. Cross correlation between the techniques was performed whenever possible in order to compare the relative accuracy of the techniques as well.
Investigation and Characterization of Thin Mocvd Copper Films From Pyrazolylborato - Copper (I) Complexes
Authors: Plappert E.-C. , Dahmen K.-H. , Van Den Bergh H. , Stumm T. , Hauert R. 
Published: April 2011

ABSTRACTThin copper layers were prepared via MOCVD from volatile pyrazolylborato - copper (I) complexes.Experiments involved chemical vapour deposition in a low pressure reactor between 150 - 350°C in H2/N2/He mixtures were carried out.Substrate temperature, source temperature and gas composition were varied to obtain the optimum growth rate.The copper layers were characterized by optical microscopy and scanning electron microscopy, XRD, and WDX. The metallic nature of the deposited films was proved by a four - point - probe measurement of the electrical resistivity.A selective deposition on metal seeded surface sites was observed on Au, Al, Pt and W vs. Si02- Antiselective deposition was achieved on Pd seeded samples.
InGaN/AlGaN Double-Heterostructure Blue Leds
Authors: Nakamura Shuji 
Published: April 2011

ABSTRACTHigh-brightness InGaN/AlGaN double-heterostructure (DH) blue-light-emitting diodes (LEDs) with a luminous intensity of 1.2 cd were fabricated successfully for the first time. As an active layer, a Zn-doped InGaN layer was used. The peak wavelength and the full width at half-maximum of the electroluminescence were 450 nm and 70 nm, respectively. The forward voltage was as low as 3.6V at 20 mA.
Oxidation and ion Damage of Diamond by Reactive Ion Etching
Authors: Beerling T. E. , Helms C. R. 
Published: April 2011

ABSTRACTOxygen is a commonly used etchant of carbon materials, including diamond. In this work, we examine the effects of oxygen ion bombardment to diamond surfaces, as might be encountered in a reactive ion etching (RIE) process. Surfaces were characterized using Electron Energy Loss Spectroscopy (EELS) and Auger Electron Spectroscopy (AES). EELS was used to determine the presence of non-diamond carbon at the surface which may form due to ion damage. AES was used to determine the presence of oxygen on the diamond surface from oxygen ion bombardment. The effect of ambient molecular oxygen present during inert ion bombardment is also addressed. EELS was also used to determine the state of diamond surfaces that were bombarded with hydrogen ions, as might be used in the removal of adsorbed oxygen.