bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Luminescence Band in Silicon Implanted with Phosphorus and Boron
Authors: Srivastava A.K. , Sharma D.K. , Narasimhan K.L. , Sarkar D. , Premchandran V. 
Published: March 2011

AbstractPhotoluminescence measurements on silicon implanted with boron, phosphorus, and dual implanted with phosphorus and boron are reported. A high intensity luminescence band between 0.9–1.03 eV is observed in the samples with dual implantation of boron and phosphorus. The luminescence band has similar spectral characteristics as that of the 1.018 eV W or II band which is observed in silicon samples irradiated with neutrons or ions. However the annealing behaviour of the luminescence band observed in our samples differs considerably from that of the W band, whose intensity increases on annealing at 525 K and is quenched on heating to 600 K. The luminescence band in our samples is not annealed out even at 900 C. The temperature dependence of the intensity of the luminescence band is also studied. It shows excitonic behaviour with an activation energy of 52 meV.
Electronic Structure of Vacancy-Phosphorus Impurity Complexes in Silicon
Authors: Xu Hongqi , Lindefelt U. 
Published: March 2011

AbstractWe present a systematic theoretical investigation on four vacancy-phosphorus impurity complexes in silicon, i.e., a vacancy with one through four phosphorus impurities on the nearest neighbour sites of the vacancy, using a semi-empirical self-consistent tight-binding theory. The calculations are based on the Lanczos-Haydock recursion Green’s function method. The predicted energy levels in the band gap for the five cases, the isolated Si vacancy and the four complexes, show a remarkable regularity. We shed light on this regularity by relating it to the localization of the wavefunctions on the Si and P atoms surrounding the vacancy. We compare our results with experimental work.
New DLTS Peaks Associated with New Donors and Rodlike Defects in Czochralski Silicon
Authors: Kamiura Yoichi , Hashimoto Fumio , Yoneta Minoru 
Published: March 2011

AbstractWe have studied the effects of low-temperature preannealing and carbon on new donor formation at 650°C in phosphorus-doped Czochralski (CZ) silicon by deep-level transient spectroscopy (DLTS). In not preannealed carbon-lean samples, only a weak continuous DLTS spectrum often reported so far was observed. The intensity of this broad feature became significantly stronger in not preannealed carbon-rich samples. On the contrary, preannealed samples showed no such continuous spectra but two new DLTS peaks arising from shallow donor levels. Carbon enhanced the low-temperature peak, but retarded the high-temperature one. The latter peak is in strong correlation with the rodlike defect.
High-Resolution Spectroscopy of Point Defects in Silicon
Authors: Grimmeiss H.G. , Kleverman M. , Olajos J. 
Published: March 2011

AbstractThe paper briefly outlines recent developments in high resolution spectroscopy of point defects in silicon. One of the methods, namely photothermal ionization spectroscopy (PTIS) is discussed in detail. Impurities induced by selenium and several transition metals are used as examples m order to illustrate the powerful scope of both transmission and PTIS measurements. These measurements are capable of providing unique information on the electronic properties of point defects, even when the defects exhibit complex excitation spectra.
Electronic Structure of Two Sulphur-Related Bound Excitions in Silicon Studied by Optical Detection of Magnetic Resonance
Authors: Chen W.M. , Henry A. , Janzén E. , Monemar B. , Thewalt M.L.W. 
Published: March 2011

AbstractWe report an investigation on the electronic structure of two bound exciton (BE) systems from a complex defect in S-doped Si, by optical detection of magnetic resonance (ODMR). A spin-triplet (S=1) is identified to be the lowest electronic state of the BE's, which gives rise to deep photoluminescence (PL) emissions when recombining. A weak anisotropy of the magnetic interaction of the BE’s (not possible to resolve in Zeeman data) is revealed, which leads directly to the determination of the symmetry for the excited state of the defect. A S-related complex model is suggested as the identity of the defect. A critical test of two possible metastable configurations of the constituents of a single defect is undertaken.
An Electron Paramagnetic Resonance Investigation of Iron-Indium Pairs in Silicon
Authors: Emanuelsson P. , Gehlhoff W. , Omling P. , Grimmeiss H. G. 
Published: March 2011

AbstractThree different Electron Paramagnetic Resonance (EPR) signals, one trigonal and two orthorhombic, which originates from iron-indium pairs in silicon are investigated. It is shown that the two orthorhombic spectra can be explained as transitions within the two doublets of a S=3/2 system with a large zero-field splitting. The temperature dependence of-the intensities reveals that the newly discovered spectrum corresponds to the lower doublet and that the zero-field splitting is 9.8 ± 2.0 cm-1.
Effects of Confinement on the Optical Properties of a Shallow Acceptor and its Bound Exciton in Narrow GaAs/AIGaAs Quantum Wells
Authors: Holtzv P.O. , Sundaram M. , Rune G.C. , Monemar B. , Merz J.L. , Gossard A.C. 
Published: March 2011

AbstractTransitions from the 1s ground state to 2s excited states of the Be-acceptor confined in GaAs/AIGaAs quantum wells (QWs) have been observed via two independent spectroscopic techniques: Two-hole transitions of the bound exciton (BE) measured in selective photoluminescence and Resonant Raman Scattering. The dependence of the 1s - 2s transition energy on the QW thickness (50 Å < Lz < 140 Å) has been studied for the case of acceptors in the center of the QW. The experimentally determined 1s - 2s transition energies have then been added to recently calculated binding energies for the 2s excited state in order to obtain the total binding energies for the acceptor at different confinements. The derived binding energies are finally compared with theoretical predictions. The same kind of measurements have been performed for a QW with a given thickness, but in which the position of the acceptor has been varied from the center to the edge of the QW.The dependencies of the binding energies of the exciton bound to the investigated acceptor on the QW thickness and the position of the acceptor in the QW have also been studied. For the case of varying QW thickness, an almost linear relationship between the binding energies of the BE and the acceptor binding the exciton is found. This fact implies that a correspondence to Haynes' rule in bulk material could be applied to these QW systems, but in this case for the same acceptor at different binding energies due to the effect of varying confinement.
Intrinsic Luminescence of GaAs/AIGaAs Heterojunctions in a Transverse Electric Field
Authors: Zhao Q.X. , Bergman J.P. , Holtz P.O. , Monemar B. , Hallin C. , Sundaram M. , Merz J.L. , Gossard A.C. 
Published: March 2011

AbstractRadiative recombination of the two dimensional electron gas (2DEG) in a modulation doped GaAs/AIGaAs heterojunction (the so called H-band luminescence) has been studied under transverse electric field perturbation (i.e. perpendicular to the layers) in special structures prepared by molecular beam epitaxy. Both positive and negative gate voltages have been applied to the GaAs/AIGaAs interface, and shifts of the H-band energy position depending on the gate voltage are induced by the corresponding changes in the notch potential and the potential across the GaAs layer. It is demonstrated that a transverse electric field allows a simple way to modify the width and shape of the potential, so that detailed spectroscopy can be done on the recombination of carriers localized in a interface potential.
Optically Detected Magnetic Resonance of a Hydrogen-Related Complex Defect in Silicon
Authors: Chen W.M. , Awadelkarim O.O. , Monemar B. , Lindström J.L. , Oehrlein G.S. 
Published: March 2011

AbstractWe present for the first time an optically detected magnetic resonance (ODMR) study of a hydrogen-related defect in silicon. The defect is present in hydrogenated boron-doped silicon single crystals, after room-temperature electron-irradiation. A spin-triplet (S=1) is shown to be the electronic state responsible for the observed ODMR spectrum. An angular dependence study of the ODMR spectrum reveals a C2v defect symmetry. The defect model is discussed in terms of a di-hydrogen-vacancy complex. The role of this defect as an efficient recombination channel (presumably non-radiative) for the non-equilibrium free carriers is also demonstrated.
Complex Defects in Semiconductors
Authors: Monemar B. 
Published: March 2011

AbstractComplex defects in semiconductors are briefly reviewed, with emphasis on the electronic structure. Classes of such defects with a varying degree of complexity are discussed, with reference to recent optical data for neutral defects in GaP and silicon. These include PGa-antisite related substitutional complexes in GaP, Gai-acceptor complexes in GaP, substitu-tional chalcogen complex defects in silicon and vacancy-impurity complexes in silicon.
Modeling of the Diffusion of Hydrogen in Silicon
Authors: Mathiot D. , Ballutaud D. , De Mierry P. , Aucouturier M. 
Published: March 2011

AbstractA model is proposed to describe hydrogen motion in silicon near 150°C. This model leads to a consistent view of H° behaviour in low doped n and p-type Si, with a diffusivity in agreement with the high temperature data. On the other hand, a systematic variation of DH+ with the boron concentration forces us to conclude that some still unknown interactions take place and contribute to hydrogen trapping in highly doped p-Si.
Electronic Structure and Hyperfine Parameters for Hydrogen and Muonium in Silicon
Authors: Van De Walle Chris G. 
Published: March 2011

AbstractFirst-principles spin-density-functional calculations are used to evaluate hyperfine and superhyperfine parameters for hydrogen and muonium at various sites in the Si lattice. The results can be directly compared with values from muon-spin-rotation experiments, leading to an unambiguous identification of “anomalous muonium” with the bond-center site. The agreement found in this case instills confidence in the general use of spin-density-functional calculations for predicting hyperfine parameters of defects.
Hydrogen in Crystalline Silicon under Compression and Tension
Authors: Nichols C.S. , Clarke D.R. 
Published: March 2011

AbstractThe behavior of hydrogen in crystalline silicon (c-Si) containing regions of compressive or tensile stress is important for understanding the solute’s interaction with dislocations, grain boundaries, and crack tips. A series of first-principles total-energy calculations probing the stable site for hydrogen as a function of its charge state, the Fermi level position, and the crystalline lattice constant has been performed. We find that the stable site for hydrogen depends critically on both pressure and on the hydrogen charge state. Furthermore, hydrogen is predicted to undergo a transition from an interstitial site to the bond-center site as a function of pressure.
Hydrogen Induced Defects at Silicon Surfaces and Buried Epitaxial Misfit Dislocation Interfaces
Authors: Zhou Tian-Qun , Radzimski Zbigniew , Xiao Zhigang , Sopori Bhushan , Rozgonyi George A. 
Published: March 2011

AbstractA silicon epitaxial structure containing spatially confined arrays of misfit dislocations has been used in order to investigate the interaction between hydrogen and individual extended defects. Hydrogen was introduced using a Kaufman plasma ion beam source. A characteristic Si-H peak at 2100 cm-1 was obtained using multiple internal reflection infrared spectrophotometry. Microdefects such as gas bubbles and {111} planar defects were found near the surface, as well as at the misfit dislocation interfaces, using transmission electron microscopy. A heavily damaged region was obtained on the top Si surface and an extended area SEM/EBIC contrast was obtained due to a surface electrical field.
Sn-H Complex in Hydrogen Pass Ivated GaAs
Authors: Kozuch D. M. , Stavola Michael , Pearton S. J. , Abernathy C. R. , Lopata J. 
Published: March 2011

AbstractIt is confirmed that Sn donors in GaAs are passivated by exposure to a hydrogen plasma. The Sn-H complexes give rise to vibrational absorption bands at 1327.8 cm-1 and 967.7 cm-1 that are assigned to H-stretching and H-wagging modes respectively. A study of the thermal stability of the Sn-H complexes shows that they dissociate for annealing temperatures above ~150°C. The properties of the Sn-H complexes are compared to those of other donor-H complexes. Our results suggest a configuration for the complex with H at the antibonding site adjacent to the Sn.
Reassessment of Acceptor Passivation Models in p-Type Hydrogenated GaAs
Authors: Szafranek I. , Stillman G.E. 
Published: March 2011

AbstractThe existing microscopic models of acceptor passivation in p-type hydrogenated GaAs are reviewed in light of new experimental results concerning the relative thermodynamic stability of the passivating complexes. In particular, the present model for neutralization of Group II acceptors, Be, Mg and Zn, on Ga sites is shown to be inadequate to account for the observed trends, which imply existence of a strong interaction between the hydrogen and acceptor. It is proposed that a direct acceptor-hydrogen bond is formed due to attractive Coulomb interaction between the ionized species. The relative stability of the pair complex can be then explained based on electronegativity of the acceptor species. Passivation at intermediate pair separations up to about twice the Bohr radius of the nearest acceptor, is also discussed.
Hydrogen Passivation of Interfacial Defects in MOCVD grown GaAs/InP
Authors: Swaminatan V. , Chakrabarthi U. K. , Hobson W. S. , Caruso R. , Lopata J. , Pearton S. J. 
Published: March 2011

AbstractThe results of a low temperature (5K) photoluminescence study of hydrogenation of GaAs on InP grown by metal organic chemical vapor deposition are presented. An emission band at ~ 1.4 eV originating from the GaAs/InP interracial region shows a 30 fold increase in intensity relative to the GaAs band edge emission after exposure to hydrogen plasma for 30 min at 250°C. This improvement in intensity is attributed to hydrogen passivation of defects at the heterointerface caused by the large (≈4%) lattice mismatch between GaAs and InP. The passivation effect recovers on annealing the hydrogenated sample at 350°C. Excitation dependence of the ~1.4 eV band suggests that the interfacial region consists of a compositionally graded layer. Further, this band shifts to higher energy on annealing the sample in the temperature range 150-450°C with the hydrogenated sample exhibiting a larger shift than the untreated sample. It is suggested that the annealing induced peak shift arises due to intermixing of the compositionally graded interface and that the degree of intermixing is greater in the hydrogenated sample compared to the untreated sample.
A Steady-State Model for Coupled Defect Impurity Diffusion in Silicon
Authors: Morehead F. F. , Lever R. F. 
Published: March 2011

AbstractWe extend our earlier model which was proposed to explain tails in the diffusion profiles of high concentration boron and phosphorus in silicon. Our quasi-steady-state approach is generalized here to include both vacancies (V) and interstitials (I) at equivalent levels. I-V recombination is regarded as near local equilibrium, occurring through reactions of the defects with defect-impurity pairs. This approach leads to the well-known plateau, kink and tail in high surface concentration P diffusions in Si and to the less well recognized tails in B as well. Our extended model, in its simplest form, allows a more complete and less restrictive treatment of Au diffusion in Si. An important advantage is the direct inclusion of these defect-impurity interactions and the resulting gradients in the defect concentrations.
Extreme Supersaturation of Oxygen in Low Temperature Epitaxial Silicon and Silicon-Germanium Alloys
Authors: Schwartz P.V. , Sturm J.C. , Garone P.M. , Schwarz S.A. 
Published: March 2011

AbstractWe report the low temperature growth (625 - 700 °C) of epitaxial silicon and silicon-germanium alloy films by vapor phase techniques with oxygen concentrations approximately 1020 cm-3. These concentrations are well above the accepted solid solubility for oxygen in silicon. The films, however, have excellent structural and electrical properties with virtually no stacking faults or “haze”. Infrared transmission analysis suggests the possible presence of OH, but the exact nature of the oxygen is not known.
An Anomalous Vacancy Diffusion in Silicon during the Antimony Drive-in Diffusion
Authors: Wijaranakula W. , Matlock J.H. 
Published: March 2011

AbstractIn the substrate region underneath the antimony buried layer, an enhanced oxygen donor generation and a retardation of the oxygen precipitation were observed. Both phenomena can be explained by the vacancy mechanism in which the charged vacancies dominate at high temperatures. Based upon this hypothetical model, it is suggested that the intrinsic vacancy concentration could play a significant role in both oxygen thermal donor generation and oxygen precipitation in silicon.
Diffusion of Point Defects in a Stressed Simple Cubic Lattice
Authors: Maroudas Dimitrios , Brown Robert A. 
Published: March 2011

AbstractA systematic theoretical and computational study is presented for the diffusion of point defects in a stressed cubic lattice. The study combines an atomistic description of point defect migration with a continuum model for point defect transport. Moment analysis of the macroscale transport equation gives expressions for the drift velocity and the diffusivity tensor of the point defects, which are calculated by a dynamic Monte Carlo simulation of the defect migration process. Results are presented for the case of diffusion under a constant force of interaction between the applied stress on the crystal and the defects. The continuum model gives the general constitutive model for stress-assisted point defect diffusion.
The Enhancement of the Interdiffusion in Si/Ge Amorphous Artificial Multilayers by Additions of B and Au
Authors: Park B. , Spaepen F. , Poate J.M. , Jacobson D.C. 
Published: March 2011

AbstractAmorphous Si/ amorphous Ge artificial multilayers were prepared by ion beam sputtering. Boron or gold impurities were introduced into the Si/Ge multilayers by ion implantation or during the sputtering deposition. Diffusion coefficients were determined by measuring the decrease in the intensity of the first order X-ray diffraction peak resulting from the composition modulation. It was found that the interdiflusion of Si and Ge in their amorphous phase can be enhanced by doping. The enhancement factor is independent of the degree of structural relaxation, as observed by the decrease of diffusivity with annealing time, of the amorphous phase. A model is proposed that describes this behavior in terms of electronic effects, introduced by the dopants, on the pre-existing structural defects governing diffusion.
Hydrogen Diffusion and Complex Formation in Silicon
Authors: Borenstein J.T. , Tulchinski D. , Corbett J.W. 
Published: March 2011

AbstractThe kinetics of hydrogen diffusion and complex formation in crystalline silicon are investigated using a model previously developed to explain the influence of dopant type and concentration on observed deuterium profiles in silicon. The predictions of the model have been shown to be in close agreement with recent SIMS profiles of deuterated FZ-Si crystals, with the in-diffusion process dominated by trapping at impurity sites and by the formation of immobile hydrogen molecules.Previous studies have treated the surface concentration of hydrogen and the capture radii of hydrogen at complexes as free kinetic parameters. We present an analytic relationship between the diffusion coefficient D of neutral hydrogen and both the hydrogen surface concentration and the capture radius for molecule formation. The consequences of fixing D at the known high-temperature value for the diffusion coefficient in the model are determined. The existence of this analytic relation reduces the number of free parameters in the kinetic model and leads to an improved understanding of hydrogen reactions in silicon.
Room-Temperature Diffusion of Mn in CdTe and the Formation of Cd1-xMnxTe
Authors: Wall A. , Raisanen A. , Haugstad G. , Franciosi A. 
Published: March 2011

AbstractDeposition of Mn at room temperature onto atomically clean CdTe(110) surfaces yields atomic interdiffusion for metal coverages <3 angstroms with Mn atoms occupying cation sites within the surface and near-surface layers of the semiconductor. Synchrotron radiation photoemission studies with variable photoelectron escape depth indicate the formation of a relatively homogeneous semiconductor surface alloy. The highest Mn concentration observed in the alloy exceeds those obtainable with bulk crystal growth methods.
The Role of Charged Point Defects on the Diffusion Behavior of Silicon in GaAs
Authors: Murray Jeffrey J. , Deal Michael D. , Stevenson David A. 
Published: March 2011

AbstractA multilayered Si doped MBE structure was used to study the effective diffusivity of Si and the results are modeled with an (n/ni)2 dependence over the temperature range of 750°C – 950°C. An activation energy, Ea′, of 4.0 eV is obtained which is higher than normally reported in the literature. This higher Ea′ value results from appropriate accounting of the temperature dependence of ni, which is often neglected in the expression for Deff. Si diffusion at a buried n+/n++junction of a MOCVD grown structure also follows an (n/ni)2 dependence. These results support a Fermi-level model of Si diffusion in GaAs and suggest that the local point defect chemistry of the GaAs, through Si doping, is responsible for this diffusion behavior, regardless of the proximity to the surface.
Electric Field Enhancement of Electron Emission from DX Centers and Consequences
Authors: Bourgoin J.C. , Zazooi M. , Feng S.L. , von Bardeleben H.J. , Alaya S. , Maaref H. 
Published: March 2011

AbstractWe present data which show that electron emission from the DX center is sensitive to the Poole-Frenkel effect. We demonstrate that this result implies that the DX center is an L effective-mass state of the donor impurity accompanied by a small lattice relaxation. We show that all the observations so far obtained on this center are in agreement with this model.
Characterization of Deep-Level Defects in Semi-Insulating GaAs and InP by Photoinduced Transient Spectroscopy (PITS)
Authors: Kaminski Pawel 
Published: March 2011

AbstractDeep states in semi-insulating (SI) materials :GaAs:Cr ,un-doped GaAs and InP:Fe are investigated by Photoinduced Transient Spectroscopy (PITS) .The relationship between the Hall mobility in undoped SI GaAs and occurrence of the EL2-related peak in the PITS spectrum is shown.
Optically Detected Magnetic Resonance of Group IV and Group VI Donors in Al0.6Ga0.4As/GaAs Heterostructures
Authors: Glaser E. , Kennedy T.A. , Molnar B. , Mizuta M. 
Published: March 2011

AbstractThe influence of chemically different donor species on the nature of shallow donor states in Al0.6Ga0.4As/GaAs heterostructures has been investigated by optically detected magnetic resonance (ODMR). Previous theoretical work by Morgan predicts a triplet state for group IV donors and a singlet state for group VI donors. ODMR experiments were performed on as-grown and implanted Si-, Se-, and S-doped epitaxial layers of Al0.6Ga0.4As grown on (001) GaAs substrates. The effective-mass states are modified by the heter-oepitaxial strain in these layers. The Si donors are characterized as quasi-independent valley states. The Se and S donors have valley-orbit splitting energies (i.e. chemical shifts) of 19-20 meV . The results indicate that Si, Se, and S donors are on the lattice sites in the metastable state of DX.