bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interstitial Defect Reactions In Silicon
Authors: Zhao S. , Agarwal A. M. , Benton J. L. , Gilmer G. H. , Kimerling L. C. 
Published: April 2011

AbstractThe interaction between self-interstitials (Sii), impurities, and dopants in Si leads the formation of undesirable point defects which affect device operation. Electron beam irradiation has been used to generate Sii and initiate defect reactions, and the hierarchy and competition of interstitial defect reactions involving O, C, B, and P in Si have been explored by DLTS measurements. We describe the interstitial defect reactions as a three-step process: (i) displacement reaction for the generation of Sii, (ii) Watkins replacement reaction for the generation of C and B interstitials (Ci and Bi), and (iii) diffusion limited reaction for the formation of pairs. Within the framework of reaction kinetics, for the first time, we have successfully set up a nonlinear system model to simulate the reaction processes. The interstitial migration enthalpy and the pair formation capture radius are two parameters used in the model to describe long range migration and near neighbor interaction. The good agreement between the model and experiments not only supports the defect assignments by DLTS, but also provides an initial glimpse into the interaction of point defects in Si.
Effects of H+-Implantation On Electron Traps In N-Type Si Induced by P+ Pre-Implantation
Authors: Ito Akira , Iwata Hiroyuki , Tokuda Yutaka 
Published: April 2011

AbstractThe change of the concentration of electron traps in n-type Si induced by P+ implantation (300keV, l×109 cm−2) with subsequent H+-implantation has been studied by deep level transient spectroscopy. H+-implantation is performed at room temperature to a dose of 2×1010cm−2 in the range 30 to 120keV. First P+ implantation induces six electron traps (Ec-0.12, 0.15, 0.21, 0.26, 0.39, 0.49eV). H+-implantation additionally induces an electron trap (Ec-0.32eV) which is related to hydrogen. The subsequent H+-implantation partly decreases the concentration of the electron traps induced by P+ implantation, although it increases the concentrations near the H+ projected range. 30 keV H+-implantation is mdst effective to reduce the trap concentration. The reduction of the concentration of the traps is ascribed to the reaction of pre-existing defects with interstitial or vacancy defects formed by subsequent H+-implantation.
Evaluation Of Proton-Induced Deep Levels In n-Si
Authors: Kono K. , Kishimoto N. , Amekura H. , Saito T. 
Published: April 2011

AbstractDeep level transient spectroscopy (DLTS) has been conducted to reveal electronic states of deep centers in n-Si, under 17 MeV-proton irradiation. The DLTS device was installed into the beam line of the cyclotron. The in-situ experiment was concentrated on, to study the dynamical defect evolution and the effect of irradiation temperature on the deep centers. DLTS signals of four deep levels E0-E3 were observed when n-Si was irradiated at 300 K. Three of the four peaks were identified as V-O, V-V2− and P-V centers, in comparison with the past data of electron irradiation. The other unknown level (EO) was located at 0.16 eV below the conduction band, and 0.02 eV lower than the V-O level. The E0 peak showed a characteristic behavior dependent on the irradiation temperature. The EQ did not emerge when irradiated at 200 K, but appeared after being annealed at 300 K following the 200 K irradiation. The evolution of these levels was consecutively investigated with accumulating the proton fluence and with annealing after the irradiation.
Effect Of Pressure On Boron Diffusion In Silicon
Authors: Zhao Yuechao , Aziz Michael J. , Mitha Salman , Schiferl David 
Published: April 2011

AbstractWe are studying the effect of pressure on boron diffusion in silicon in order to better understand the nature of the point defects responsible for diffusion. Si homoepitaxial layers deltadoped with boron were grown using molecular beam epitaxy. Diffusion anneals were performed in a high temperature diamond anvil cell using fluid argon as a pressure medium. Diffusivities were deduced from B concentration-depth profiles measured with using secondary ion mass spectrometry. Preliminary results indicate that pressure enhances B diffusion in Si at 850 °C, characterized by an average activation volume of -0.125±0.02 times the atomic volume, and thus appear consistent with an interstitial-based diffusion mechanism. Results are compared with previous hydrostatic-pressure studies, with results in biaxially strained films, and with atomistic calculations of activation volumes for self diffusion.
The Effect Of Ion-Implantation Induced Defects On Strain Relaxation In GexSi1−x/Si Heterostuctures
Authors: Glasko J. M. , Zou J. , Cockayne D. J. H. , Gerald J. Fitz , KringhøJ P. , Elliman R. G. 
Published: April 2011

AbstractThis study examined the effect of ion irradiation and subsequent thermal annealing on GeSi/Si strained-layer heterostructures. Comparison between samples irradiated at 253°C with low energy (23 keV) and high energy (1.0 MeV) Si ions showed that damage within the alloy layer increases the strain whereas irradiation through the layer/substrate interface decreases the strain. Loop-like defects formed at the GeSi/Si interface during high energy irradiation and interacting segments of these defects were shown to have edge character with Burgers vector a/2<110>. These defects are believed responsible for the observed strain relief. Irradiation was also shown to affect strain relaxation kinetics and defect morphologies during subsequent thermal annealing. For example, after annealing to 900°C, un-irradiated material contained thermally-induced misfit dislocations, while ion-irradiated samples showed no such dislocations.
Effect of Stresses on Defect Nucleation in Si1−.xGex/Si Heteroepitaxial Systems
Authors: Ozkan Cengiz S. , Nix William D. , Gao Huajian 
Published: April 2011

AbstractStrained layer semiconductor structures provide possibilites for novel electronic devices. When a semiconductor layer is deposited epitaxially onto a single crystal substrate with the same structure but a slightly different lattice parameter, the semiconductor layer grows pseudomorphically with a misfit strain that can be accomodated elastically below a critical thickness. When the critical thickness is exceeded, the elastic strain energy builds up to a point where it becomes energetically favorable to form misfit dislocations. In the absence of a capping layer, surface roughening may also take place which causes strain relaxation in the form of 2D ridges or islands via surface diffusion. At sharp valley regions on the surface, amplified local stresses can cause further defect nucleation and propagation. These defects can be detrimental to the electrical performance of devices by acting as electron-hole recombination centers or current leakage channels. In this paper, we present observations and analyses of two novel defects nucleated in heteroepitaxial Si1−xGex thin films through surface roughening. Heteroepitaxial films 500 Å thick and containing 22% Ge are deposited by LPCVD. These initially flat films are subjected to various annealing conditions in a H2 atmosphere to induce morphological evolution and defect formation. High resolution transmission electron microscopy and atomic force microscopy have been used to study the morphology of defects at the film surface and at the film/substrate interface.
Characterization Of Hydrogen-Related Defects In Iron-Doped Indium Phosphide
Authors: Leigh W. B. , Bliss D. , Bryant G. , Iseler G. , Larkin J. , Wolk J. 
Published: April 2011

AbstractWe have investigated the effect of annealing on hydrogen-related donors in crystals of InP using Hall effect, infrared absorption, and photorefractive gain measurements. Hydrogen is believed to be incorporated during growth, forming a donor complex around an indium vacancy with hydrogen saturating all four dangling bonds. By observing the local vibrational mode of the hydrogen complex using infrared absorption at 2316 cm−1 was possible to observe a decrease in the concentration of the hydrogen defect after annealing. In the undoped crystal, the disappearance of this defect is accompanied by a decrease in the free carrier concentration as measured by Hall effect. These changes are correlated with a decrease in the absorption due to Fe2+ centers, which form when donors are compensated by the neutral acceptor Fe3+. The existence of the hydrogen-related donor complex is further substantiated by photorefractive experiments using 1064nm irradiation on the iron doped samples. All of the measurements point to the role of hydrogen as a contributor to the net shallow donor concentration in InP crystals.
Long-Living Shallow Donor Excited States And Fir-Ir Up-Conversion In Gap:Te
Authors: Ganichev S. D. , Yassievich I. N. , Raab W. , Zepezauer E. , Prettl W. 
Published: April 2011

AbstractTellurium donors in GaP have been ionized by phonon assisted tunneling in the electric field of pulsed far-infrared laser radiation. In response to the laser pulse a photoconductive signal has been detected with a fast component reproducing the laser pulse and a slow component which rises after the irradiation has ceased and finally exponentially decays with a strongly temperature dependent time constant in the range of microseconds to several milliseconds. This temporal structure of the signal is explained by a cascade capture mechanism and subsequent accumulation of carriers in a long-living shallow donor excited state, identified as valley-orbit split 1s(E) level of Te. The final step of recombination is achieved by radiative transitions, which is proved by the observation of far-infrared to mid-infrared up-conversion.
A Refined Model For Threading Dislocation Filtering In InxGa1−xAs/GaSAs Epitaxial Layers
Authors: Macpherson G. , Goodhew P. J. 
Published: April 2011

AbstractA model is presented for the filtering of threading dislocations in InxGa1−xAs/GaAs epitaxial single layers by accurate control of the layer thickness. The model developed differs from previous models since the InxGa1−xAs growth is restricted to less than ten times the Matthews and Blakeslee critical thickness (hc) where the asymmetry in the [110] and [110] dislocation densities is the greatest. Beyond this thickness it is shown that the removal or annihilation of threading dislocations (TDs) in the epilayer is more than offset by the introduction of new TDs from spiral and Frank-Read type sources. Results from strain sensitive etching with CrO3 aqueous solutions show that the TD density can be reduced by up to a factor of ten below that found in the substrate. Atomic force microscopy shows that these thin layers maintain a high level of surface quality with an absence of striations. Evidence is also shown that this type of defect etching is suitable for revealing large scale dislocation blocking in samples that have been grown significantly beyond 10hc.
Electrical Characterization Of Defects Introduced During Plasma-Based Processing Of GaAs
Authors: Auret F. D. , Myburg G. , Meyer W. E. , Deenapanray P. N. K. , Nordhoff H. , Murtagh M. , Ye Shu-Ren , Masterson H. J. , Beechinor J. T. , Crean G. M. 
Published: April 2011

AbstractDLTS revealed that each plasma type (He and SiCl4) introduced its own characteristic set of defects. Some of the defects created during He processing and one defect introduced by SiCl4 etching had identical electronic properties to those introduced during high energy (MeV) He ion bombardment. SiC14etching introduced only two prominent defects, one of which is metastable with electronic properties similar to a metastable defect previously reported in high and low energy He-ion bombardment of Si-doped GaAs. IV measurements demonstrated that the characteristics of SBDs fabricated on He-ion processed surfaces were very poor compared to those of control diodes (diodes fabricated on surfaces cleaned by conventional wet etching). In contrast, the properties of SBDs fabricated on SiCl4 etched surfaces were as good as, and in some cases superior to, those of control diodes. SBDs fabricated on annealed (at 450°C for 30 minutes) He-processed samples exhibited improved but still poor rectification. In contrast, SBDs fabricated on annealed SiCl4 etched surfaces had virtually the same characteristics as those fabricated on unannealed SiCl4 etched samples.
Photoluminescence And Electron Paramagnetic Resonance Of Nitrogen-Doped Zinc Selenide Epilayers
Authors: Moldovan M. , Setzler S.D. , Yu Z. , Myers T.H. , Halliburton L.E. , Giles N.C. 
Published: April 2011

AbstractPhotoluminescence (PL) and electron paramagnetic resonance (EPR) studies were performed on a series of ZnSe samples grown by molecular beam epitaxy. The PL has been studied as a function of excitation wavelength, power, temperature, and time. The PL data indicates that the broad emission from a heavily nitrogen-doped ZnSe film is composed of three distinct recombination processes. The EPR spectra taken at 8 K and 9.45 GHz show an isotropic signal at g = 2.0027(3) which we attribute to singly ionized selenium vacancies (Vse+). The PL and EPR data help to clarify the role of defects in the compensation of heavily nitrogen-doped ZnSe thin films.
Surface Of Li-Doped ZnSe Grown On Misoriented GaAs(001) Substrates
Authors: Yoneta Minoru , Ohishi Masakazu , Saito Hiroshi , Ohura Mitsuhiro , Fujii Katsumoto , Hioe Yoshihiko 
Published: April 2011

AbstractThe surface of Li-doped ZnSe grown on misoriented GaAs(001) substrates by molecular beam epitaxy is studied by means of reflection high energy electron diffraction. Sharp and curved streaky RHEED patterns are observed for all the layers grown on the misoriented substrate towards [110], irrespective of off-angles. No curved pattern, however, is observed on ZnSe layers grown on misoriented GaAs(001) towards [110] with off-angle larger than 5°. We confirmed that the Li-array is surely formed along [110], and that the length of the Li-array is longer than 32Å to be observable as curved streaks. It is also confirmed that the growth rate of Li-doped ZnSe is proportional to the step density, and that the growth rate on the misoriented substrate towards [110] is higher than that on the misoriented substrate towards [110]. The photoluminescence spectra of Li-doped ZnSe layers grown on misoriented GaAs are reported.
Damage Induced By A Low-Biased 92-MHz Anode-Coupled Reactive Ion Etcher Using Chlorine-Nitrogen Mixed Plasmas
Authors: Saitoh Tadashi , Gotoh Hideki , Sogawa Tetsuomi , Kanbe Hiroshi 
Published: April 2011

AbstractDry-etch damage, introduced by a low biased 92-MHz anode-coupled reactive ion etching (RIE), in MBE-grown undoped GaAs has been characterized by photoreflectance (PR) and photoluminescence (PL) measurements. PL spectra show emission peaks at 1.516 eV (excitons) and at 1.494 eV (D-A, B-A) before etching, whereas a new emission peak at around 1.488–1.490 eV appears after the RIE. The depth distribution of this new emission center, examined by PL measurements with a combination of step wet etching, has a Gaussian-shape with a l/e value of 56 nm. A very small number of nonradiative recombination centers are considered to be generated, because the integrated PL intensity including both emission peaks at 1.490 eV and at 1.516 eV is the same before and after the RIE. The surface recombination rate of the sidewall formed by the RIE is almost the same as that of the wet-etched surface. This low-damage etching has been applied to fabricate ultra-fine GaAs patterns to provide a nanometer-scale ridge structure with a cross-section 15-nm wide by 150-nm high. The low damage etching condition is also suitable for precise fabrication.
Electronic Properties Of Defects Formed In n-Si During Sputter-Etching In An Ar Plasma
Authors: Deenapanray P. N. K. , Auret F. D. , Schutte C. , Myburg G. , Meyer W. E. , Malherbe J. B. , Ridgway M. C. 
Published: April 2011

AbstractWe have employed current-voltage (IV), capacitance-voltage (CV) and deep level transient spectroscopy (DLTS) techniques to characterise the defects induced in n-Si during RF sputter-etching in an Ar plasma. The reverse leakage current, at a bias of 1 V, of the Schottky barrier diodes fabricated on the etched samples was found to decrease with etch time reaching a minimum at 6 minutes and thereafter increased. The barrier heights followed the opposite trend. The plasma processing introduced six prominent deep levels below the conduction band of the substrate. A comparison with the defects induced during high energy (MeV) alpha-particle, proton and electron irradiation of the same material revealed that plasma-etching created the VO- and VP-centres, and V2-10. Some of the remaining sputter-etching-induced (SEI) defects have tentatively been related to those formed during either 1 keV He- or Ar-ion bombardment.
Diamondlike Carbon Materials as Low-k Dielectrics for Multilevel Interconnects in Ulsi
Authors: Grill A. , Patel V. , Saenger K.L. , Jahnes C. , Cohen S.A. , Schrott A.G. , Edelstein D.C. , Paraszczak J.R. 
Published: April 2011

AbstractA variety of diamondlike carbon (DLC) materials were investigated for their potential applications as low-k dielectrics for the back end of the line (BEOL) interconnect structures in ULSI circuits. Hydrogenated DLC and fluorine containing DLC (FDLC) were studied as a low-k interlevel and intralevel dielectrics (ILD), while silicon containing DLC (SiDLC) was studied as a potential low-k etch stop material between adjacent DLC based ILD layers, which can be patterned by oxygen-based plasma etchingIt was found that the dielectric constant (k) of the DLC films can be varied between >3.3 and 2.7 by changing the deposition conditions. The thermal stability of these DLC films was found to be correlated to the values of the dielectric constant, decreasing with decreasing k. While DLC films having dielectric constants k>3.3 appeared to be stable to anneals of 4 hours at 400 °C in He, a film having a dielectric constant of 2.7 was not, losing more than half of its thickness upon exposure to the same anneal. The stresses in the DLC films were found to decrease with decreasing dielectric constant, from 700 MPa to about 250 MPa. FDLC films characterized by a dielectric constant of about 2.8 were found to have similar thermal stability as DLC films with k >3.3. The thermally stable FDLC films have internal stresses <300 MPa and are thus promising candidates as a low-k ILD.For the range of Si contents examined (0-9% C replacement by Si), SiDLC films with a Si content of around 5% appear to provide an effective etch-stop for oxygen RIE of DLC or FDLC films, while retaining desirable electrical characteristics. These films showed a steady state DLC/SiDLC etch rate ratio of about 17, and a dielectric constant only about 30% higher than the 3.3 of DLC.
Optimization of AICu Wiring Delay in Advanced CMOS Technology
Authors: Stamper A. K. , McGahay V. , Shapiro M. , Miller L. A. , Tian X. , Bryant A. , Serianni L. A. 
Published: April 2011

AbstractFluorinated high-density plasma and plasma-enhanced CVD SiO2 inter-metal dielectrics have been evaluated for 0.50- through 0.25- μm generation CMOS. Several integration issues are discussed, including the impact of fluorine-doped SiO2 on the yield, reliability, and RC delay of 0.7 - 1.8 μm pitch back-end-of-the-line AlCu/tungsten-stud wiring.
Interconnect Process Technology Using Perfluorocyclobutane (PFCB)
Authors: Townsend P. H. , Shaffer E. O. , Mills M. E. , Blackson J. , Radler M. J. 
Published: April 2011

AbstractA novel polymer dielectric derived from tris-perfluorocyclobutene(PFCB) monomer has been investigated as a thin film dielectric. The dielectric constant of this material has been measured at 2.35. PFCB is applied from a hydrocarbon solvated solution using conventional spin coating equipment onto the substrate and produces highly uniform films after curing at 300 °C.This paper describes the processing and properties of films derived from PFCB, and examines the interactions between the polymer and metals at the interfaces. In particular, the interfaces formed by the deposition of Cr or Co onto PFCB are unchanged after 30 minutes at 390 °C. The interface formed by the application of the polymer onto Ta is similarly unaffected by high temperatures. The interfaces formed by the deposition of Ta or Ti onto the polymer surface did not remain intact, with substantial quantities of the metals permeating the polymer after high temperature exposures. This behavior is discussed relative to the thermo-physical properties of the metal fluorides.
Toughened, Inorganic-Organic Hybrid Materials for Microelectronic Application
Authors: Hedrick J. L. , Srinivasan S. , Cha H.-J. , Yoon D. , Flores V. , Harbison M. , Pietro R. Di , Hinsberg W. , Deline V. , Brown H. R. , Sherwood M. , Paulson E. , Miller R. D. , Cook R. , Liniger E. , Simonyi E. , Klaus D. , Cohen S. , Hummel J. 
Published: April 2011

AbstractTransparent, nanophase-separated, inorganic-organic hybrid polymers with dielectric constants below 3.0 have been prepared from reactively functionalized poly(amic ester) derivatives and substituted, oligomeric silsesquioxanes. These hybrid materials are stable to 400 °C and above and form tough, crack-free films. Induced cracking and crack propagation studies performed with the application of external stress suggest a maximum critical film thickness of at least 2.0 μm under severe stress conditions. These hybrid materials appear to be significantly toughened by the chemical incorporation of the polyimides relative to organically modified silicates and spin-on-glasses without significantly effecting other important polymer properties of the silicates.
Mechanical and Dielectric Properties of Low Permittivity Dielectric Materials
Authors: Alptekin A. , Czeremuszkin G. , Martinu L. , Meunier M. , Sacher E. , DiRenzo M. 
Published: April 2011

AbstractThe dielectric and mechanical properties of low permittivity dielectric/metal system consisting of fluoropolymers and copper were studied. The types of polymers in this study include sputtered Teflon, plasma-deposited fluoropolymers and the soluble Teflon AF1600. All these fluoropolymers have dielectric constants below 2.0 and dissipation factors below 0.001. Copper was either evaporated or sputtered. Adhesion of copper to fluoropolymers was studied using scratch and peel tests. Different thermal treatment techniques were applied to enhance adhesion, including preannealing in vacuum or in atmosphere, as well as postannealing in vacuum. The results show generally poor adhesion for evaporated copper, with substantial improvement for sputtered copper; however thermal treatments enhance adhesion in some cases. FTIR, surface tension and XPS experiments were carried out in an effort to understand these effects. Our findings will be discussed in terms of the various effects contributing to copper/fluoropolymer adhesion.