bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultra-shallow Junction Formation via GeB- ion Implantation of Si
Authors: Lu Xinming , Shao Lin , Jin Jianyue , Li Qinmian , Rusakova I. , Chen Q. Y. , Liu Jiarui , Chu Wei-Kan , Ling Peiching 
Published: April 2011

AbstractGeB− Cluster ions have been used to effectively produce 0.65-2keV boron for low energy ion implantation. We have generated the GeB− cluster ions using the SNICS ion source (source of negative ion by cesium sputtering). Shallow junctions have been made by the GeB− cluster ions implanting into Si substrates at 15keV, 1×1015/cm2 and 5keV, 5×1014/cm2. The junction depth as small as 37nm has been achieved by rapid thermal annealing of the 5 keV sample at 1000°C for 1 second. A two-step annealing was also performed to study the diffusion of B in the GeB− ion cluster implanted Si by annealing the 15 keV implanted sample at 550°C/300sec+1000°C/10sec. We found that the junction depth of the two-step annealed sample was only half of the one-step annealed sample. TEM (transmission electron microscopy) showed clear recrystallization of the amorphized layer with no observable residual defects. We briefly discussed the role of Ge in regards to reduction of the junction depth.
Dopant - Extended Defects Interactions: The Case of Aluminum
Authors: Ortiz Ch. , Mathiot D. , Dubois Ch. , Alquier D. , Jérisian R. 
Published: April 2011

AbstractWe studied the Al redistribution in the vicinity of a well-defined EOR band formed by Ge pre-amorphization. Aluminum was implanted in Si at 3 MeV to a low dose before the preamorphization step in order to localize the as-implanted Al peak away from the EOR band. Rapid thermal annealings were performed in the temperature range [900-1000°C] for times varying from 20 s up to 200 s. The results of this study evidence a clear accumulation of the dopant on the extended defects, indicating a direct trapping mechanism of the dopant by the EOR.
Diffusion Engineering by Carbon in Silicon
Authors: Goesele Ulrich , Laveant Pierre , Scholz Rene , Engler Norbert , Werner Peter 
Published: April 2011

AbstractThe possibility to suppress undesirable diffusion of the base dopant boron in siliconbased bipolar transistor structures by the incorporation of a high concentration of carbon has lead to renewed interest in the behavior of carbon in crystalline silicon. The present paper will review essential features of carbon in silicon including solubility, diffusion mechanisms and precipitation behavior. Based on this information the possibilities to use carbon to influence diffusion of dopants in silicon by the introduction of non-equilibrium concentrations of intrinsic point defects will be discussed as well as the reason for the relatively high resilience against carbon precipitation. Interactions between carbon and oxygen will be mentioned, especially in the context of an as yet unexplained fast out-diffusion of carbon close to the surface.
Clustering Equilibrium and Deactivation Kinetics in As doped Si
Authors: Nobili Dario , Solmi Sandro , Shao Jenta , Merli Marco 
Published: April 2011

AbstractClustering equilibrium was studied on silicon on insulator specimens uniformly doped with As at concentrations CAs up to 7.6 × 1020 cm−3. Values of the carrier density n* after equilibration at 700, 800 and 900°C are reported. It is shown that both the concentration and the temperature dependence of n* can be accurately simulated by a simple cluster model detailed in the Appendix. The analysis of the clustering kinetics of these compositions was performed at temperatures in the range 550 to 800°C. It is found that at 800°C the kinetics accurately complies with the rate equation:-dn/ dt = A{exp[-(E-αn)/kT] - (n0- n)/( n0- n*) exp[-(E-αn*)/kT]which is the one reported in Ref.[14] complemented by the second term on the right to account for the declustering process. Deviations leading to rates lower than predicted by the above equation are observed by annealing at lower temperatures. The dependence of this phenomenon on composition and temperature is reported.
Quantitative Depth Profiles of Vacancy Cluster Defects Produced by MeV Ion Implantation in Si: Species and dose Dependence
Authors: Kalyanaraman R. , Haynes T.E. , Jacobson D.C. , Gossmann H.-J. , Rafferty C.S. 
Published: April 2011

AbstractMonte Carlo simulation codes such as TRIM or MARLOWE show a net displacement of interstitials with respect to vacancies from the Frenkel pairs produced in implant cascades. As a result, defect profiles after recombination have an excess of vacancies (Vex) in the shallow region of these implants, with excess interstitials near the projected range Rp. Typically, accurate estimates of the Vex distribution are computer intensive as the complete history of each damage cascade must be recorded. In this work we introduce a method for fast estimation of the Vex profile based on the derivative of the recoil distribution obtained from binary collision simulations using the Kinchen-Pease approximation for damage production. Also, Au labeling has been used to quantitatively analyze and compare the experimental depth profiles of Vex produced by implants of B, Si, and Ge into Si for a range of doses. Specific conditions like matching of the projected range of the implanted ions and matching of the number of Frenkel pairs created have been compared. This detailed study and comparison with simulation provides the first systematic, quantitative measurements of the Vex concentrations over such a range of species and doses. In analogy to the “+ number” for excess interstitials from ion implantation, we determine the range of “minus (-) numbers”, that is the number of excess vacancies per implanted ion for the different species. For Si it is constant in the dose range studied at -0.05, while for B it is -0.001 to -0.004 and for Ge, -0.1 to -0.2. The general shapes of the Vex profiles are similar to those obtained from simulation. Evidence is presented that one significant difference, namely an experimentally observed vacancy depletion near the surface, may be due to the diffusion and annihilation of vacancies at the surface. In addition, an increased nucleation probability of vacancy defects close to Rp may account for the growth of excess vacancies from close to Rp towards the surface with increasing implant dose.
Epitaxial CoSi2 formation by a Cr or Mo interlayer
Authors: Detavernier C. , Van Meirhaeghe R.L. , Cardon F. , Maex K. , Brijs B. , Vandervorst W. 
Published: April 2011

ABSTRACTWe have studied CoSi2 formation in the presence of a Cr or Mo interlayer or capping layer. We shall show that, contrary to what was previously reported, Cr and Mo may be used as interlayers to grow epitaxial CoSi2. However, unlike for Ti, the thickness of the interlayer is very important. If the Cr or Mo interlayer is too thick (> 5 nm), polycrystalline CrSi2 or MoSi2 are formed first and epitaxial growth of CoSi2 becomes impossible. However, both XRD and random/channeling RBS results indicate that for a 2-3 nm interlayer of Cr or Mo, CoSi2 forms epitaxially on Si(100). For thinner interlayers, there is a preferential (220) and (400) orientation. This can be explained by the presence of Cr or Mo on the CoSi grain boundaries, which will affect the heterogeneous nucleation of CoSi2.
A Closer “Look” at Modern Gate Oxides
Authors: Baumann Frieder H. , Chang C.-P. , Grazul John L. , Kamgar Avid , Liu C. T. , Muller David A. 
Published: April 2011

ABSTRACTUsing high resolution TEM (HRTEM), we identified some process induced ‘weak spots’ in SiO2 layers: First, we observed thinning in the periphery of the transistor, i. e. near the boundary to the shallow trench isolation. At the boundary to the shallow trench, the Si substrate gradually changes its orientation from <100> to <110>, which results in an unexpected oxidation behavior in this region. Secondly, we observed the intrusion of poly-Si grains from the gate into the gate oxide, resulting in local thinning of the dielectric. Using image simulations, we show that conventional high resolution TEM can reveal the interface roughness only to a very limited extend.
A Two-Step Spacer Etch for High-Aspect-Ratio Gate Stack Process
Authors: Yu Chien , Wise Rich , Domenicucci Anthony 
Published: April 2011

ABSTRACTA highly selective nitride etch was developed for gate stack spacer process in advanced memory programs. Based on methyl fluoride chemistry with better than 8:1 selectivity of nitride:oxide, this process exhibits minimal erosion to the underlying RTO thermal oxide for consistent diffusion ion-implant control. As the groundrule changed to 0.175um and below, a two-step etch scheme was employed to maintain the profile control in high-aspect-ratio structures. The stability and repeatability of the process is demonstrated in the SPC chart of the post etch FTA site measurement.
Formation and Electrical Transport Properties of Nickel Silicide Synthesized by Metal Vapor Vacuum Arc Ion Implantation
Authors: Zhang X. W. , Wong S. P. , Cheung W. Y. , Zhang F. 
Published: April 2011

ABSTRACTNickel disilicide layers were prepared by nickel ion implantation into silicon substrates using a metal vapor vacuum arc ion source at various beam current densities to an ion dose of 6×1017 cm−2. Characterization of the as-implanted and annealed samples was performed using Rutherford backscattering spectrometry, x-ray diffraction, electrical resistivity and Hall effect measurements. The temperature dependence of the sheet resistivity and the Hall mobility from 30 to 400 K showed peculiar peak and valley features varying from sample to sample. A two-band model was proposed to explain the observed electrical transport properties.
Using Wafer-Scale Patterns for CMP Analysis
Authors: Lee Brian , Gan Terence , Boning Duane S. , David Jeffrey , Bonner Benjamin A. , McKeever Peter , Osterheld Thomas H. 
Published: April 2011

ABSTRACTA new set of wafer-scale patterns has been designed for analysis and modeling of key CMP effects. In particular, the goal of this work is to develop methods to characterize the planarization capability of a CMP process using simple measurements on wafer scale patterns. We examine means to pattern large trenches (e.g. 1 to 15 mm wide and 15 mm tall) or circles across 4” and 8” wafers, and present oxide polish results using both stacked and solo pads in conventional polish processes. We find that large separation (15 mm) between trenches enables cleaner measurement and analysis. Examination of oxide removal in the center of the trench as a function of trench width shows a saturation at a length comparable to the planarization length extracted from earlier studies of small-scale oxide patterns. Increase in polish pressure is observed to decrease this saturation point. Such wafer scale patterns may provide information on pad flexing limits in addition to planarization length, and promise to be useful in both patterned wafer CMP modeling and studies of wafer scale CMP dependencies such as nanotopography.
Fundamental Studies on the Mechanisms of Oxide CMP
Authors: Mahajan Uday , Lee Seung-Mahn , Singh Rajiv K. 
Published: April 2011

ABSTRACTIn this paper, results of studies on the addition of salt to a polishing slurry, in terms of its effect on slurry stability, SiO2 polishing rate and surface roughness of the polished surface are presented. Three salts, viz. LiCl, NaCl and KCl were selected, and three concentrations were tested. Polishing rate measurements using these slurries show that adding salt leads to increased removal rate without affecting surface roughness significantly. Based on these results, we can say that the agglomerates formed by adding salt to the slurry are fairly soft and easily broken during the polishing process. In addition, turbidity and particle size measurements show that significant coagulation of the particles in the slurry occurs only at the highest salt concentration, and is fastest for LiCl and NaCl, with KCl showing the slowest coagulation. From these results, it can be concluded that the enhancement in polish rate is due to increased contact at the wafer-pad-slurry interface, and not due to formation of larger agglomerated particles in the slurry. This is because of reduced electrostatic repulsion between these three surfaces, due to the screening of their negative surface charge by the metal ions in solution, resulting in a higher wear rate.
A Novel Single Step Lapping and Chemo-Mechanical Polishing Scheme for Antimonide Based Semiconductors Using 1 µm Agglomerate-Free Alumina Slurry
Authors: Dutta P.S. , Gutmann R.J. , Keller D. , Sweet L. 
Published: April 2011

ABSTRACTA novel approach for a single step lapping and chemical-mechanical polishing of antimonide-based III-V compounds using agglomerate-free alumina slurries is presented. Relatively high removal rates, minimal scratching, and low surface roughness have been obtained. The effects of slurry preparation cycle on the slurry properties and chemomechanical polishing results are discussed.
An Image Analysis Technique For Assessing Particle Size And Agglomeration Tendency Of Slurries
Authors: Machinski Susan R. , Richardson Kathleen A. , Dogariu Aristide 
Published: April 2011

ABSTRACTUnderstanding the time-dependent behavior and size of particulate systems, specifically, particles in abrasive slurries, is a key part of chemical mechanical polishing (CMP). Microscopy and image analysis enables both qualitative and quantitative analysis of particle interaction behavior in diluted samples of such particulate suspensions. A technique using microscopy and image analysis has been developed specific to the analysis of suspensions of, micron size or larger, abrasive particle slurry systems. This technique has been applied to aluminum oxide (Al2O3) slurries and measurements of particle size and stability have been obtained with good accuracy and precision.
Removal Rate, Uniformity and Defectivity Studies of Chemical Mechanical Polishing of BPSG Films
Authors: Bonner Benjamin A. , Fishkin Boris , David Jeffrey , Garretson Chad , Osterheld Thomas H. 
Published: April 2011

ABSTRACTWafers where deposited with BPSG films having phosphorus concentration varying from 3.65 to 6.25% and boron concentration varying from 4 to 5.7%. These wafers were polished using CMP and the rates were found to depend on dopant concentrations. A fit to the data indicated that removal rates were more than 3 times as sensitive to boron concentration compared to phosphorus concentration. For a constant phosphorus concentration of 5%, each percent increase in boron increases CMP removal rate by 340 Å/min. For a constant boron concentration of 5%, each percent increase in phosphorus increases CMP removal rate by 96 Å/min.
Dry Etching of MRAM Structures
Authors: Pearton S.J. , Cho H. , Jung K.B. , Childress J.R. , Sharifi F. , Marburger J. 
Published: April 2011

ABSTRACTA wide variety of GMR and CMR materials have been patterned by high density plasma etching in both corrosive (Cl2-based) and non-corrosive (CO/NH3) plasma chemistries. The former produce much higher etch rates but require careful in-situ or ex-situ, post-etch cleaning to prevent corrosion of the metallic multilayers. The former may have application for shallow etching of NiFe-based structures, but there is little chemical contribution to the etch mechanism and mask erosion can be a problem. The magnetic performance of patterned MRAM elements is stable over long periods (>1 year) after etching in Cl2 plasmas, provided a suitable cleaning protocol is followed. It is also clear that high ion energies during patterning of magnetic materials can have a significant influence on their coercivity. The effects of ion energy, ion flux and process temperature are discussed.
Selective Area Chemical Vapor Deposition of Chromium Oxides
Authors: Cheng Ruihua , Borca C.N. , Dowben P.A. 
Published: April 2011

ABSTRACTWe demonstrate that two-phase CrO2 and Cr2O3 thin films can be grown by using selective organometallic chemical vapor deposition through the oxidation of Cr(CO)6 in an oxygen environment. While the magnetization measurements show that both chromium oxides are present, the relative weight of each phase depends on the oxygen partial pressure. Changes of the Curie temperature, Tc, and the saturation magnetization field may be possible by controlling the stoichiometry.
TEM to Support Magnetic Media Development in YR2000
Authors: MoberlyChan Warren J. , Dorsey Paul , Nolan Tom , Alex Michael , Yamashita Tom 
Published: April 2011

ABSTRACTTEM provides fast and statistical support for magnetic recording media development. Turn-around time including sample preparation, data collection and computer analysis is reduced to ∼3 hours. Rapid, systematic TEM analysis is shown to accurately measure crystallographic Orientation Ratio (OR) on mechanically textured media by diffraction analysis; elucidate grain separation by Weak Beam Dark Field Imaging; and determine the crystallographic relationship between cubic-NiAl seed layers and hexagonal cobalt-alloy (Co) layers. Novel evidence for reduction of the number of preferred orientations in sequentially grown epitaxial films is presented, which explains the “2-&-1/4-D isotropic” growth orientation and the high magnetic squareness of Co media grown on nearly randomly oriented “3D-isotropic” NiAl underlayers.
Microstructures and Soft Magnetic Properties of High Saturation Magnetization Fe-Co-N alloy Thin Films
Authors: Sun N. X. , Wang S. X. , Hung Chin-Ya , Chien Chester X. , Tong Hua-Ching 
Published: April 2011

ABSTRACTHigh saturation magnetization soft magnetic materials are required for future high-density recording heads as well as high frequency inductors. In this work, (Fe0.7Co0.3)1−xNx (or in short FeCoN) alloy films were synthesized with a high saturation magnetization of 24.5 kG, a hard axis coercivity of 5 Oe, an easy axis coercivity of 18 Oe, and a resistivity of 55 μΩcm. The FeCoN film sandwiched between two permalloy layers (5 nm) shows very good magnetic softness, a low hard axis coercivity of 0.6 Oe, an easy axis coercivity of 7.8 Oe, an excellent in-plane uniaxial anisotropy with an anisotropy of about 20 Oe, an initial permeability of 1000, and a roll-off frequency of 1.5 GHz. In order to understand the effect of the permalloy layers on the FeCoN layer, we fabricated four film structures: single layer FeCoN film; FeCoN film sandwiched between two permalloy layers on both sides; FeCoN film with one permalloy layer as the underlayer; and FeCoN film with one permalloy layer as caplayer. All these film structures were both magnetically and structurally characterized and compared. Structural characterization shows that there is no significant difference in the grain size of the FeCoN single layer and the FeCoN layer sandwiched between two permalloy layers. The four film structures have almost the same amount of compressive stress, about −300 MPa; and their saturation magnetostriction constants are also very close, in the range of 39.6×10−6 to 44.3×10−6. Difference in the crystallographic textures was observed in the pole figures for the FeCoN single layer and FeCoN film with permalloy underlayer.
Structural and Elastic Response of Mo/Ni Multilayers to Ion Irradiation
Authors: Pacaud Jérôme , Martin Franck , Michel Anny , Jaouen Christiane , Djemia Philippe , Ganot François 
Published: April 2011

ABSTRACTMo/Ni multilayers are investigated by x-ray diffraction and Brillouin light scattering before and after ion induced stress relaxation and mixing. Study of the evolution of interplanar distances in both layers as a function of the period exhibits a strong anomaly of the Mo (110) distance (in the growth direction) that can be correlated with the elastic anomaly. The very low interplanar distance in the molybdenum layers found after stress relaxation seems to favor an explanation of this behavior based on the diffusion of Ni in the Mo layers during the growth.
Lateral and Vertical Ordering of PbSe Self-Assembled Quantum Dots in PbSe/PbEuTe Superlattices
Authors: Holý V. , Stangl J. , Springholz G. , Pinczolits M. , Bauer G. 
Published: April 2011

ABSTRACTThe shape and the positions of self-organized PbSe quantum dots embedded in PbEuTe are studied by means of grazing-incidence small angle x-ray scattering and x-ray diffraction. Using a detailed numerical analysis of the measured x-ray data, we have determined a truncated pyramidal shape of the free-standing dots. The type of the lateral dot ordering depends substantially on the period of the PbSe/PbEuTe superlattice. In the case of smaller periods, the lateral ordering of the dots obeys a short-range order model and we have determined the statistical properties of the dot arrangement. For intermediate spacer thicknesses the dots form a hexagonal lattice. For larger periods, the dots are completely uncorrelated and their distribution can be described as a two-dimensional ideal gas. From coplanar x-ray diffraction we have determined additionally the vertical correlation of the dot positions changes from a mere vertical correlation for small superlattice periods, to a distorted trigonal lattice for the intermediate periods. For the largest period, no vertical correlation of dot positions is observed.
InGaAs/GaAs Quantum Dot Interdiffusion Induced by Cap Layer Overgrowth
Authors: Jasinski J. , Babinski A. , Czeczott M. , Bozek R. 
Published: April 2011

ABSTRACTThe effect of thermal treatment during and after growth of InGaAs/GaAs quantum dot (QD) structures was studied. Transmission electron microscopy and atomic force microscopy confirmed the presence of interacting QDs, as was expected from analysis of temperature dependence of QD photoluminescence (PL) peak. The results indicate that the effect of post-growth annealing can be similar to the effect of elevated temperature of capping layer growth. Both, these thermal treatments can lead to a similar In and Ga interdiffiusion resulting in a similar blue-shift of QD PL peak.
Optoelectronic Device Applications of Self-Organized In(Ga,Al)As/Ga(Al)As Quantum Dots
Authors: Bhatiacharya P. , Krishna S. , Zhu D. , Phillips J. , Klotzkin D. , Qasaimeh O. , Zhou W. D. , Singh J. , Mccann P. J. , Namjou K. 
Published: April 2011

ABSTRACTSelf-organized growth of strained semiconductor heterostructures has enabled the realization of ordered arrays of quantum dots that can be incorporated into the active region of electronic and optoelectronic devices. Highly uniform In(Ga)As/Ga(Al)As with greatly reduced photoluminescence linewidths (FWHM=19 meV, T=17K) have been grown and characterized. Various aspects of carrier dynamics in these dots, such as measurement of carrier relaxation times and the modulation bandwidths of quantum dot lasers, estimation of the tunneling time in vertically coupled dots along with tuning of the intersubband electronic energy levels have also been studied. The favorable relaxation times can be exploited to realize far infrared emission and detection based on intersubband transitions in the dots. The optoelectronic properties of the dots and the dynamics of carriers therein are also extremely attractive for high-speed wavelength switching and the design of electro-optic modulators. The electro-optic coefficients in the quantum dots have been measured and the linear E-O coefficient, r1 =2.6 ×10−11m/V, is found to be comparable to that in LiNbO3