bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of Trapped Interstitials During Rapid Thermal Annealing
Authors: Pennycook S. J. , Culbertson R. J. 
Published: March 2011

ABSTRACTDuring the rapid thermal annealing of ion implanted layers, trapped interstitials are responsible for transient enhanced dopant diffusion and the formation of a band of defects at the mean projected ion range. We describe the detailed nature and extent of these effects and show how they can be predicted in practice. We present a model which explains why trapping only occurs with group V implantation and describe double implantation experiments which confirm the model and show how the formation of projected range defects can be suppressed.
A GaAs Sagfet Process Using TiSi2 and Rapid Thermal Annealing
Authors: Wood D. , Mun J. 
Published: March 2011

ABSTRACTFor the first time a combination of titanium disilicide and rapid thermal processing has been used to produce a high temperature stable gate on gallium arsenide. A barrier height of 0.79 V with an ideality factor of 1.02 has been obtained after annealing up to 800°C, and useful results are found up to 900°C. Auger analysis shows little intermixing of the silicide with the underlying substrate, which is not the case for conventional annealing. The advantages of titanium disilicide over the more commonly used tungsten silicide with regard to film resistivity and stress will be discussed. A self-aligned gate MESFET (SAGFET) process has been developed using TiSi2 as the gate material.
Comparison of Isothermal Anneal Techniques for be or Si Implanted S.I. InP
Authors: Molnar B. , Dietrich H. B. 
Published: March 2011

ABSTRACTThis paper presents a study of the annealing of Be and Si implants into InP. It compares rapid thermal anneal (RTA) and furnace anneal (FA) techniques over a temperature range of 600-;900° C. The results demonstrate that RTA results in activation and mobilities as good as those obtained by FA for both Si and Be implant. The background Fe concentration of S.I. InP substrates lead to substantial differences in activation. Arrhenius fit of optimal activation data of Si indicates an activation energy of 1.8 eV. The Si implants display no redistribution during either type of annealing, while the Be implants display more than one type of redistribution. Moreover, the complete description of the Be redistribution requires the knowledge of both the atomic and the electronic profiles. Capless annealing eliminates the additional processing steps of capping but it also sets a limit on the maximum temperature and time of the annealing.
A New Model of Tail Diffusion of Phosphorus and Boron in Silicon
Authors: Morehead Frederick F. , Lever R. F. 
Published: March 2011

ABSTRACTIt is well known that high surface concentration phosphorus diffusion leads to deeply penetrating “tails” in its concentration profile. At 700 °C the tail diffusivity exceeds that of low concentration phosphorus by a factor of a thousand. Less spectacular, but very significant tailing also affects tioron, making the conventional models contained in commonly available process simulation programs quite inaccurate for boron diffusions with high surface concentrations. We show that the observed tailing can be accounted for by a model whose central assumption is the local equality of dopant and oppositely directed defect fluxes. As predicted by the model, the effect is greatest for normal processing at low temperatures for high surface concentrations. It is minimal for the high temperatures of rapid thermal annealing and unrelated to transient effects.
Dopant Redistribution During Pd2Si Formation Using Rapid Therm1al Annealing
Authors: Alvi Nadeem S. , Kwong Dim L. , Hopkins Craig G. , Baumane Scott G. 
Published: March 2011

ABSTRACTRapid thermal annealing (RTA) has been used to form Pd2Si by reacting thin layers of Pd metal on As implanted Si. An enhanced growth rate for the Pd2Si has been measured which does not obey the diffusion limited growth kinetics as reported for the furnace reacted Pd2Si. The growing Pd2Si results in As redistribution which is sufficient to displace the shallow p-n junction as the silicide/silicon interface approaches the junction position. The As implanted profile changes little in the Pd2Si region, with As accumulating at the leading edge of the silicide/silicon interface.
MOLECULAR DYNAMICS STUDIES OF THE COHERENCY OF MONOLAYER FILMS
Authors: GRABOW MARCIA H. , GILMER GEORGE H. 
Published: March 2011

AbstractThe equilibrium configurations of monolayer films on crystalline substrates have been investigated using molecular dynamics techniques. Misfit dislocation densities are found to differ from those predicted by elasticity theory, because of the more realistic interatomic potential employed in the simulations (Lennard-Jones), and the absence of constraints on atomic positions. Two distinct dislocation core structures are observed, with a discontinuous transition between the two as the external conditions are changed. Shockley partial dislocations are found to be stable for a large range of misfits in the case of FCC (001) substrates, and recently an experimental observation of these dislocations was reported. The stability of monolayer films relative to the formation of three-dimensional clusters is also considered.
DIFFRACTION STUDIES OF METAL-SEMICONDUCTOR INTERFACES
Authors: CHERNS D. , KIELY C.J. 
Published: March 2011

AbstractThe use of convergent beam electron diffraction patterns (CBPs) for investigating metal—semiconductor interfaces in plan—view samples is considered. It is shown that a wide—angle diffraction technique provides a sensitive method of measuring tetragonal distortions in NiSi 2/(001)Si bicrystals. A study of CBP symmetry and the detailec branch structure in higher order Laue zone rings has enabled the interfacial rigid body displacement in NiSi 2/(001)Si and Al/(001)GaAs films to be determined.
STRAIN MEASUREMENT IN EPITAXIAL NiSi2/Si(lll) BY MeV ION CHANNELING
Authors: OKAMOTO MASAKO , HASHIMOTO SHIN , HUNT B.D. , SCHOWALTER L.J. , GIBSON W.M. 
Published: March 2011

AbstractStrains in both type-A and type-B NiSi2 epitaxial films grown on Si(lll) substrates were measured by means of MeV 4He+ ion channeling. The results show the critical thickness to maintain pseudomorphic growth strongly depends on theepitaxial orientation of the NiSi2 film. The difference in critical thicknesses between type-A and type-B NiSi2 can be explained by considering the different type of misfit dislocations introduced at the interface. Namely, at the type-B interface, 1/<112> partial dislocations associated with interface steps are allowed while they are prohibited at the type-A interface. Dislocation densities measured by TEM also support these results.
Electron Beam Induced Current Studies of Nickel Silicide/Silicon Schottky Barrier Heights
Authors: Gibson J.M. , Joy D.C. , Tung R.T. , Ellison J.L. , Pimentel C. , Levi A.F.J. 
Published: March 2011

AbstractWe discuss the use of electron beam induced current measurements in a scanning electron microscope to deduce local Schottky barrier height with high spatial resolution. For theNiSi2/Si system, using UHV-prepared thin “templates”, wedemonstrate the uniformity of barrier heights for A or B single crystal films. In comparison, there is evidence for local variation of barrier height in mixed A+B films. Quantitative models for EBIC dependence on barrier height are discussed. Local variations in barrier height can be overlooked by other techniques and may be much more common than previously suspected.
STLOY OF Nb/Si MULTILAYERS
Authors: Li C. , Cai X. , Ye Z. , Zhang H. , Zharng W. , Xiong G. , Wu K. , Wang S. , Yin D. 
Published: March 2011

AbstractA systematic study of superconducting Te, Hc and also the behavior of resistivity of Nb/Si mfltiiayers is reported. Nb and Si layers with different thicknesses were deposited alternatively in an LUIV two electron—beam evaporating installation and controlled automatically by a microcomputerquartz—monitor system. Well reproduciole results were achieved. Structural analyses show very good modulated structure with (110)textured polycrystallino Nb and] amorphous Si layers. Superconducting Tc of Nb/Simultilayers are significantly higher than that of the sputtered Nb/Ge system. Thevariation of Hc(T) in parallel field manifests a 2D–3D crossover with transformation temperature of 0.7– 0.8 Tc. The possible mechanism and implication of these phenomena were discussed.
DEFECTS IN MBE SILICON
Authors: CHRENKO R.M. , SCHOWALTER L.J. , HALL E.L. , LEWIS N. 
Published: March 2011

AbstractA study of defects that are observed in Si MBE layers under certain growth conditions is reported. Optical microscopy examinations of unetched and etched layers reveal particle-like defects of micron size, stacking faults, dislocations, and saucer pits. TEM shows interfacial defects of tens of Angstroms size at the substrate-epitaxial layer interface. Reproducible defect densities are given for various in-situ cleaning procedures.
STABILITY OF SI-DOPED AlGaAs/GaAs MODFET STRUCTURES DURING CONVENTIONAL FURNACE AND RAPID OPTICAL ANNEALING.
Authors: ABROKWAH J. K. , HIBBS H. , DANIELS R. R. , JOSLYN P. 
Published: March 2011

AbstractThe use of an AlGaAs/n-GaAs superlattice in place of the n-AlGaAs layer in MODFET devices reduces the light and temperature sensitivity of the threshold voltage. This paper considers the stability of Si doped superlattices under annealing conditions required for activation of the implant in the self-aligned gate MODFET fabrication process. Rapid optical annealing does not significantly degrade the superlattice structure. The DX center concentration in the superlattice structures is a factor of 30 less than measured in conventional MODFET structures. High performance MOOFET devices have been fabricated using the self-aligned gate process with rapid optical annealing.
THE INFLUENCE OF RECONSTRUCTION ON THE INITIAL STAGES OF SILICON MOLECULAR BEAM EPITAXY
Authors: Gossmann H.-J. , Feldman L.C. 
Published: March 2011

AbstractHigh energy ion scattering/channeling and low energy electron diffraction are usedfor an investigation of the initial stages of interface formation during Si homoepitaxy. We find a strong dependence of the atomic. reordering – a necessary condition for pseudomorphic growth – on substrate surface, deposition temperature and Si coverage: (1) Si deposition at 300 K reorders the Si(100) substrate reconstruction in a layer by layer manner. In contrast Si( 111) is unaffected by Si deposition at that temperature. This difference between Si(100) and Si( 111) can be understood in terms of different structural models. (2) On both surfaces deposition at 300 K results in a disordered overlayer. (3) As a direct consequence of the dependence of the reordering on reconstruction we find a lower epitaxial temperature (≈570 K) for Si(100) than for Si(l 11) (≈790 K).
MEASUREMENT OF THE BANDGAP OF GexSi1−x/Si STRAINED-LAYER HETEROSTRUCTURES
Authors: LANG D. V. , PEOPLE R. , BEAN J. C. , SERGENT A. M. 
Published: March 2011

AbstractWe have used photocurrent spectroscopy to measure the optical absorption spectra of coherently strained layers of GexSi1−x grown on {001} Si by molecular beam epitaxy. A dramatic lowering of the indirect bandgap, relative to that of unstrained bulk Ge-Si alloys, is observed. Our results for 0 < × < 0.7 are in remarkably good agreement with recent calculations of the effects of misfit strain on the band edges of coherently strained Ge-Si heterostructures.
Optical Absorption Probability for the Zone-Folding Induced Quasi-Direct Gap in Ge(x)Si(1−x)/Si Strained Layer Superlattices
Authors: Jackson S. A. , People R. 
Published: March 2011

AbstractUsing a realistic zone-folding scheme for a Ge(x)Si(1−x)/Si strained layer superlattice having a Si-like conduction band structure (i.e ≲85% Ge) we calculate the transition probability for the zone-folding induced direct optical gap and compare it with the indirect band gap absorption probability. The results suggest that such zone-folding induced direct optical transitions are promising for optical devices made from Ge(x)Si(1−x)/Si strained layer superlattices and like structures, provided they are fabricated in such a way that the appropriate zone-folding occurs.
RAMAN SCATTERING AND X-RAY DIFFRACTION CHARACTERIZATION OF AMORPHOUS SEMICONDUCTOR MULTILAYER INTERFACES
Authors: GONZALEZ J. , ALLRED D.D. , NGUYEN O.V. , MARTIN D. , PAWLIK D. 
Published: March 2011

AbstractIn the present study, Raman spectroscopy (RS) and x-ray diffraction have been used to characterize semiconductor multilayer interfaces. A model for Raman spectra of multilayers is developed and applied to the specific case of the interfaces of a-Si/a-Ge multilayers. Quantification of the ‘blurring’ of interfaces is possible because RS is capable of directly ‘counting’ the total number of chemical bonds of a given type in the film. Multilayers, prepared by various deposition techniques, are compared. Several a-Si/a-Ge multilayers deposited by UHV evaporation (MBD) exhibit exceptionally sharp interfaces (intermixing width <l.0Å) and regular periodicities.
STRUCTURAL AND ELECTRONIC PROPERTIES OF POTASSIUM HYDROGEN INTERCALATED GRAPHITE
Authors: Yeh N. C. , Enoki T. , Salamanca–Riba L. , Dresselhaus G. 
Published: March 2011

AbstractBecause of the difference in charge transfer and superlattice formation of the various intercalant species, graphite intercalation compounds (GICs) exhibit a variety of interesting electronic properties and phonon properties. These compounds form monolayered metallic superlattices along the c—axis, in contrast to the multilayered metallic superlattices grown from MBE and sputtering synthesis methods. GICs are generally divided into donor—type and acceptor—type compounds, depending on whether the electrons are transferred to the graphite or from the graphite. The modification of the electronic energy bands of GICs by charge transfer is analogous to that of the nipi superlattices. Because of the strong electron affinity of hydrogen relative to that of graphite, the addition of hydrogen into donor—type GICs (e.g. K—GICs, KHg—GICs) modifies the charge transfer from the intercalates to the graphite л-bands. Therefore, studies of the donor—type KHx—GICs provide us with new understanding of the variation of the electronic properties of alkali—metal GICs as the as charge transfer is modified.
NUCLEATION KINETICS OF CdTe/CdTe (111) HOMOEPITAXY BY LASER MBE
Authors: Cheung J.T. 
Published: March 2011

AbstractCdTe evaporates into Cd and Te atoms under high power, pulsed laser irradiation. The mechanism is different from thermal evaporation where only atomic Cd and molecular Te are formed. The presence of Te atoms is responsible for some unique nucleation processes, such as the epitaxial growth of CdTe on (111) CdTe substrates with either polarity and the enhancement in sticking coefficient in CdTe deposition.
EPITAXY OF CdTe ON (100) GaAs
Authors: KOLODZIEJSKI L. A. , GUNSHOR R. L. , OTSUKA N. , CHOI C. 
Published: March 2011

AbstractTwo epitaxial orientations [(111) and (100)] of CdTe are grown on (100) GaAs in the presence of a 14.6% lattice mismatch. Consistent nucleation of a selected orientation is achieved by employing specific growth techniques. The growth techniques for selection of both orientations are described. High resolution electron microscopy has been used to investigate the interface between the CdTe epilayer and the GaAs substrate. For the (111) orientation strong interaction exists between the epitaxial deposit and the substrate, whereas a weakened interaction between deposit and substrate induces the (100) orientation.
Formation of a Low Thermal Donor Concentration Layer in CZ Si Wafer During 450°C/64h Annealing
Authors: Hahn S. 
Published: March 2011

ABSTRACTFor thermal donor and oxygen precipitation studies in Cz silicon wafers, extended 450°C thermal annealing (e.g., anneal at 450°C for 64 h) has frequently been used. But, our recent studies have shown that this kind of extended low temperature anealing leads to a low thermal donor (LTD) layer up to ∼ 8 um from the surface in the case of 450°C/64 h thermal annealing. In this study, effects of annealing ambients, protective layers, surface conditions, and bulk oxygen contents upon the LTD layer are discussed. Our data indicate that the LTD layer is a product of both surface- and bulk-related phenomena.
The Diffusivity and Solubility of Oxygen in Silicon
Authors: Mikkelsen J. C. 
Published: March 2011

ABSTRACTThe diffusivity and solubility are two key parameters required for understanding and modeling the behavior of oxygen in silicon. This paper gives an up to date review of experimental determinations of these parameters, including some recent unpublished data. There is very good agreement within the long-range diffusivity results determined by secondary ion mass spectrometry (SIMS), charged particle analysis (CPA), and x-ray diffraction. The oxygen diffusivity is independent of [O], orientation, ambient, or crystal doping. The data also extrapolate well to the diffusivities obtained by the intrinsic oxygen atomic hop frequency at low temperature to give a combined expression of D = 0.13 exp(−2.53eV/kT) cm2s−1. There is somewhat poorer agreement on the solubility measurements, in part due to inconsistent calibration factors and the observation of a processing-dependent extrinsic oxygen solubility. The intrinsic solubility derived from SIMS, CPA, and infrared absorption is described by [O] = 9E22 exp (−1.52 eV/kT) cm−3. Finally, the above diffusivity and solubility parameters are compared to modeling of oxygen related phenomena in silicon, such as thermal donor and precipitate formation kinetics, and interaction with point defects during the relaxation of stress-aligned dichroism.
Microdiffraction Studies of Oxygen in Silicon - A New SiO2 Phase?
Authors: Spence J. C. H. , Long N. , Bergholz W. , Kim Y. , O'Keeffe M. 
Published: March 2011

ABSTRACTEvidence for a new microcrystalline precipitate in CZ Si annealed for 256 hrs at 635°C is presented by electron microdiffraction. This may be a precursor phase for the formation of amorphous platelets [9]. Multiple scattering microdiffraction calculations which distinguish the symmetries of two models for the thermal donor are also given.
Exigent-Accommodation-Volume of Precipitation and Formation of Oxygen Precipitates in Silicon
Authors: Tan T. Y. 
Published: March 2011

ABSTRACTIn this paper we first describe, in some detail, the nature of an exigentaccommodation- volume factor associated with oxygen (Oi) precipitation in Czochralski (CZ) Si. This factor is regarded as a causal or characteristic factor which influences many aspects of the SiO2 precipitate nucleation and growth phenomena. Employing this factor, we then describe the possible explanations of two outstanding features of Oi precipitation in CZ Si: the precipitation retardation/recovery phenomena and the nucleation incubation phenomena.
Effects of Thermal Donor Generation and Annihilation Upon Oxygen Precipitation
Authors: Hahn S. , Shatas S. C. , Stein H. J. 
Published: March 2011

ABSTRACTRapid thermal annealing and furnace annealing steps have been combined to investigate the effects of thermal donor generation and annihilation upon oxygen precipitation in low and high carbon content silicon wafers. Thermal donors were formed by furnace annealing at 450°C. Rapid thermal annealing was performed in 10 s periods at temperatures between 600° and 1000°C and was followed by two step furnace annealing at 700° and 950 °C. Rapid thermal annealing separates the annealing stage for thermal donor removal from that for removal of oxygen precipitate nuclei, and a marked dependence upon carbon is observed for nuclei stability under RTA. Implications of these observations for models of precipitate nuclei are considered.
Oxygen Precipitation in Silicon: Numerical Models
Authors: Lavine J. P. , Hawkins G. A. , Anagnostopoulos C. N. , Rivaud L. 
Published: March 2011

ABSTRACTWe present a numerical model that simulates the evolution of precipitates and the diffusion of interstitial oxygen in Czochralski silicon. The growth and/or dissolution of each precipitate and the local concentration of interstitial oxygen with which the precipitates interact are followed as a function of time. We treat realistic densities of discrete, interacting precipitates and determine how the precipitate density influences the extent of the precipitation. The model also treats oxygen outdiffusion and the formation of precipitate-free or denuded zones. We apply the model to previous experimental data on the time dependence of precipitate growth and to the development of denuded zones during intrinsic gettering.
Trapping of Oxygen at Homoepitaxial Si-Si Interfaces Grown by Molecular Beam Epitaxy
Authors: Hull R. , Twigg M. E. , Bean J. C. , Gibson J. M. , Joy D. C. 
Published: March 2011

ABSTRACTInterfaces between Si substrates and epitaxial Si buffer layers grown by Molecular Beam Epitaxy (MBE) are shown to contain a high density of SiOx pockets for certain sustrate preparation conditions. It is also shown that post-deposition thermal annealing of these structures grown upon Czochralski wafers can lead to a greatly increased defect density at the interface. The primary model proposed for this increase is trapping of background oxygen diffusing from the bulk of the Czochralski substrate wafers.
Gettering of Impurities in Silicon
Authors: Ourmazd A. 
Published: March 2011

ABSTRACTDespite the apparent dissimilarities between different gettering methods, we show that many can be understood in terms of two basic mechanisms. The first involves the interaction of selfinterstitials (emitted, for example, by P in-diffusion and precipitation, 0 precipitation, or Ar implantation) with the impurities to be gettered. The second relies on a strain-field/point defect interaction (for example around a dislocation), which appears capable of enhancing the diffusivity of the impurities. In either case, gettering can be viewed as a particular and particularly useful instance of the wider class of defect/defect interactions.
Impurity Interactions with Dislocations in Silicon
Authors: Sumino Koji 
Published: March 2011

ABSTRACTA review is presented of some aspects on the interactions of light element impurities with dislocations in silicon crystals on the basis of the works done by the author's group. Topics taken up are gettering of impurities by dislocations, electrical and optical activities of impurity atoms accumulated at the dislocation core, immobilization of dislocations due to impurity gettering, and the mechanism of strengthening of silicon wafers due to doping of impurities such as oxygen and nitrogen.
Hydrogen in Crystalline Silicon
Authors: Pearton S. J. 
Published: March 2011

ABSTRACTThe ability of hydrogen to migrate in crystalline Si at low temperatures (<400°C) and bond to a variety of both shallow and deep level impurities, passivating their electrical activity, is of fundamental and technological interest. Recent results on the deactivation of the shallow acceptors in Si are compared with similar experiments in other semiconductors, microscopic models are proposed, and the implications for the states of hydrogen in the Si lattice at a variety of temperatures, and the diffusivity of some of these different states, is discussed. New results on the migration of atomic hydrogen under electronic stimulation are also detailed, along with a compendium of the deep levels in Si passivated by reaction with hydrogen. Surface damage by hydrogen-containing plasmas, and the infrared and electrical properties of H-related defect complexes are also reviewed.