bluuebunny/crossref_metadata_2025_split huggingface dataset:
MULTILAYER ANODIZATION PROFILE (MAP) A NOVEL DEPTH PROFILE TECHNIQUE FOR METALLIC–BASED LAYERED STRUCTURES
Authors: KADIN A.M. , BURKHARDT R.W. , KEEM J.E. 
Published: March 2011

AbstractA simple and inexpensive technique is described, which makes novel use of electrolytic anodization to obtain an effective depth profile of artificial nultilayered structures based on a number of refractory metals. Successful MAPs (Multilayer Anodization Profiles) have been obtained for multilayer structures of Nb/Si, W/Ti, and a variety of other material pairs, with individual layer spacings ranging from less than 10 Å to greater than 50 Å. The spatial resolution of these MAPs annears to be less than about 10 Å, and may in some cases be comparable to the interface sharpness of the sputtered films. Comparison with conventional techniques such as Auger depth profiling and low–angle x-ray diffraction is discussed. Examples of semiquantitative analysis, using the MAP technique, of changes in interface structure brought about by thermal annealing, are also presented.
HEAVILY Si-DOPED AlAs FILMS GROWN BY MOLECULAR BEAM EPITAXY
Authors: KOBAYASHI K. , KAMATA N. , SUZUKI T. 
Published: March 2011

AbstractHeavily Si-doped aluminium arsenide films on GaAs substrate by MBE have been investigated. It is found that the Si activation energy ED for AlAs films decreases with increasing Si donor concentration, approaching a few meV for n≧3×l018. The maximum free electron concentration of n=7×l018 cm−3 and electron mobility of 200 cm2/V.sec for n=5×l017 were obtained. It is also shown that the replacement of the ternary AlxGal−xAs with a superlattice having heavily Si-doped binary AlAs in the barrier layers is effective to increase free carrier concentration.
DEFECTS IN GaAs GROWN ON Ge SUBSTRATES
Authors: CARTER C. B. , COOMAN B.C. DE , CHO N.H. , FLETCHER R.M. , WAGNER D.K. , BALLANTYNE J. 
Published: March 2011

AbstractThe growth of polar semiconducting materials on non-polar semiconducting substrates is illustrated by experimental observations of GaAs grown on Ge substrates and on Ge epilayers which had been grown on Si substrates. The GaAs epilayers are grown in each case by metal-organic, vapor-phase deposition. The GaAs/Ge heterophase junction, the grain boundaries in GaAs grown on {110} Ge and on {001} Ge/Si composit substrates and the anti-phase boundaries in GaAs grown on {001} Ge substrates are eat.h illustated. The interfaces have been studied by transmission electron microscopy and reveal the pronounced faceting of the anti-phase boundaries in GaAs. Also demonstrated experimentally is the strong interaction between dislocations/grain boundaries and these anti-phase boundaries.
TWO DEFECT-RELATED PHOTOLUMINESCENCE SPECTRA AND CROSS-SECTION TEM OF MBE GROWN CdTe ON (100) InSb
Authors: FENG Z.C. , MASCARENHAS A. , CHOYKE W.J. , FARROW R.F.C. , GREGGI J. , SHIRLAND F.A. 
Published: March 2011

AbstractA series of MBE grown CdTe films were grown on (100) InSb substrates. The substrate temperature, Ts, was varied from 170° to 285°C in eleven steps. Low temperature (∿2K) photoluminescence measurements and TEM have been combined to show a strong correlation between defect density and the details of the luminescence spectra. A natural division is obtained for samples grown with substrate temperatures from 285°C to 250°C (Region I) and from 225°C to 170°C (Region II).
Infrared Absorption Studies of Thermal Donors in Silicon
Authors: Wagner Peter 
Published: March 2011

ABSTRACTInfrared absorption investigations of oxygen containing silicon reveal that the thermal donors generated by annealing around 450 °C consist of a series of shallow double donors with slightly differing ground state energies. The kinetics of formation and decay of these donors in samples with varying oxygen content annealed at temperatures between 460 and 600 °C support the relation of the thermal donors to aggregates of oxygen atoms. A preferential orientation of thermal donors induced by uniaxial stress during their growth demonstrates their low symmetry and extended defect-like nature. Optical cross sections evaluated by comparing IR-absorption spectra with resistivity measurements allow to estimate the concentrations of the different donors.
On the Kinetics of Oxygen Clustering and Thermal Donor Formation in Czochralski Silicon
Authors: Tan T. Y. , Kleinhenz R. , Schneider C. P. 
Published: March 2011

ABSTRACTWe report the results of an experiment of annealing Czochralski silicon at 450°C for up to 500 hrs. Concentrations of oxygen atoms (Ci) and thermal donors (TD) have both been monitored. Analyses of the oxygen concentration data yielded the apparent interpretation that the overall kinetics is dominated by the formation of small clusters (dimers and trimers). This cannot account for TD formation, since they are supposed to be larger clusters. On the other hand, analyses of existing TD kinetic models did not yield calculated Ci values to satisfactorily account for the present Ci data. We believe that a satisfactory TD model is not yet available.
Cluster Computations Related to Silicon Thermal Donors
Authors: Snyder Lawrence C. , Corbett James W. 
Published: March 2011

ABSTRACTAb-initio quantum chemical computations have been applied to a set of molecular clusters derived from Si5 H12 to model defects in crystalline silicon involving boron, carbon, nitrogen, oxygen, and hydrogen. In computations of defect structure, hydrogen atoms terminating silicon valencies are fixed at their computed positions in Si5H12, to represent forces from the lattice, while the position of other atoms are varied.We have computed the stable bonding structures of boron, carbon, nitrogen and oxygen atoms to a vacancy, as well as interstitial oxygen, the silicon-oxygen ylid and two oxygen atoms bound to a vacancy. The structures of the dipositive ions of the oxygen bearing clusters have been computed as part of a search for candidates for the core of the 450° C oxygen thermal donor in silicon crystal. The computed cluster energies are employed to give an account of defect thermochemistry; the addition of the free atoms to a vacancy, the addition of interstitial oxygen atoms to a vacancy, the reaction of interstitial oxygen atoms to form a vacancy-oxygen complex with the emission of silicon monoxide, and the reaction of interstitial oxygen with the dipositive ion of substitutional oxygen to form the dipositive ion of two oxygen atoms bound to a vacancy.
Transmission Electron Microscope Studies of O, C, N Precipitation in Crystalline Silicon
Authors: Bourret A. 
Published: March 2011

ABSTRACTThe understanding of the precipitation phenomena of light non dopant Impurities has been recently improved thanks to high resolution electron microscopy and microanalysis. After a one-step annealing in Czochralski silicon long coesite (SIO2) ribbons are formed between 485° and 750°C; amorphous platelets (SIOxwith x =1. 2 to 2) are formed between 650°C -1050°C. Silicon Interstitlals generated during the precipitation partly relax the strain energy associated with the volume change. These Interstltlals are also able to precipitate In various forms. After a two-step annealing both platelets and/or octahedra containing amorphous SIOxare formed. The role of carbon on oxygen precipitation Is important: It changes the nucleation parameters and gives a retardation phenomena In a two-step annealing treatment. Similar phenomena are observed in oxygen implanted silicon. The nucleation and growth process able to explain these observations is far from being well understood. The SIO2polymorphism, the Important role of SI Interstitials and the mutual attraction between oxygen and carbon are some of the ingredients which explain this complexity.
Electron Energy Loss Microspectroscopy: Small Particles in Silicon
Authors: Skiff W. M. , Tsai H. L. , Carpenter R. W. 
Published: March 2011

ABSTRACTThe method of electron energy loss spectroscopy in a transmission electron microscope is applied to the analysis of small particles in silicon. Elemental and chemical microanalysis is demonstrated on nitrogen and oxygen-associated defects in silicon, using silicon-based standards.
Oxygen Precipitation in Silicon
Authors: Hu S. M. 
Published: March 2011

ABSTRACTThe precipitation of oxygen in silicon exhibits many interesting phenomena: the precipitates are often distributed in striated zones; the morphology of precipitates changes with annealing temperatures; the kinetics of precipitation in the bulk is affected by annealing ambients and other surface treatments. These phenomena are briefly reviewed. A model consistent with all these phenomena is presented. Then, the energetics and the kinetics of nucleation and precipitation are discussed. Finally, a growth law is derived in general for disc precipitates, and applied in particular to oxygen precipitates in silicon.
Roles for A Precursor Oxide Phase in The Siting, Shaping, and Shrinking of Oxygen Precipitates
Authors: Fraundorf P. 
Published: March 2011

ABSTRACTThree separate “anomalous” effects in the precipitation of oxygen in silicon may be explained if typical poorly-crystallized platelet oxygen precipitates begin as tiny crystalline clusters. The first anomaly, sometimes referred to as the induction effect, may be explained if one postulates the existence of kinetically stable precipitate embryos (seeds) containing no more than one or two oxygen atoms. We show here that such a postulate, coupled with observations, places rather specific constraints on binding energy as a function of size for such tiny clusters. The second and third anomalies, arising in precipitate shape and retrogrowth behavior dependences, respectively, may be explained if one postulates the existence of a relatively dense precursor phase which undergoes first order phase transition, following otherwise classical rules, to the final-stage amorphous oxide normally found. In this case, both precipitate shape and strain field can be interpreted as a barometer of the interstitial ambient during key periods in a precipitate's history.
Diffusivity and Diffusion Mechanism of Oxygen in Silicon
Authors: Lee S.-Tong , Nichols D. 
Published: March 2011

ABSTRACTThe diffusivities of oxygen in Czochralski Si (CZ-Si) and float-zone Si (FZ-Si) have been measured by using secondary ion mass spectrometry. The diffusivity at 700–1160°C deduced from the outdiffused profiles of oxygen incorporated in CZ-Si shows little or no dependence on processing conditions and can be expressed as D = 0.14 exp(−2.53 eV/kT) cm2/s. Diffusivity at 700–1100°C of oxygen implanted in FZ-Si is insensitive to doses and follows D = 0.13 exp(−2.50 eV/kT) cm2/s, which agrees remarkably well with CZ-Si data. Since large variations in point-defect concentrations existed under the conditions studied, the excellent agreement among the diffusivities leads to the conclusion that point defects in Si have little effect on oxygen diffusion. This demonstrates that oxygen diffuses primarily via an interstitial mechanism in the temperature range studied.
Interaction Between Deposited Film Extrinsic Gettering and Intrinsic Gettering in CZ Silicon During Simulated CMOS Process Cycles
Authors: Hahn S. , Wong C.-C. D. , Ponce F. A. , Rek Z. U. 
Published: March 2011

ABSTRACTThe gettering effectiveness of various thin film structures on n-type CZ silicon wafers has been investigated using electron microscopy, synchrotron radiation topography and optical techniques. Polysilicon, silicon nitride, and poly/nitride films were deposited on etched wafer backsurfaces. The various materials characteristics were correlated with gate oxide breakdown voltage, minority carrier lifetime and yield of MOS capacitors. These studies show that the poly/nitride configuration is superior as a gettering technique.
The Effects of Carbon on Czochralski Silicon Used for Dynamic Random Access Memory Production
Authors: Craven R. A. , Bailey W. E. , Moody J. W. , Falster R. J. , Shive L. W. 
Published: March 2011

ABSTRACTCzochralski silicon with constant controlled oxygen level of 15+/-0.5 ppma (ASTM F121–80) and varying carbon content intentionally doped at five different levels from 0.1 ppma to 4.1 ppma (ASTM F123–81) was used to fabricate 16K dynamic random access memories, MOS test capacitors with guard rings, and pn junctions. The results of the experiment have been analyzed for relative yield to functional and refresh characteristics, MOS generation and bulk recombination lifetime, pn junction leakage, and both surface and bulk defect densities. Peak performance of the silicon did not occur at the lowest carbon level, but was dominated by the oxygen precipitate defect density and depth of the denuded zone near the active device regions. The results of the capacitor measurements, the DRAM yield measurements, the junction leakage measurements and the bulk and surface lifetime measurements are self-consistent and emphasize the need for control of the oxygen precipitation whether it is nucleated by carbon or other homogeneous and heterogeneous processes. There is no evidence that carbon has any impact on the device performance other than its impact on the precipitation kinetics of the interstitial oxygen.
Infrared Spectroscopy of Intersitial Oxygen in Silicon
Authors: Pajot Bernard , Cales Bernard 
Published: March 2011

ABSTRACTA discussion of the isotope shift of the low temperature spectrum of the stretching mode of interstitial oxygen (Oi) in silicon introduces IR results showing the interaction of Oi with the silicon lattice. Evidence is given that the temperature dependence of a combination band observed at liquid helium temperature (LHT) at 1205.7 cm−1 is responsible for the room temperature (RT) band at 1227 cm−1 and that a weak band near 1013 cm−1 is an overtone of the 518 cm−1 band.
Carbon in Crystalline Silicon
Authors: Newman Ronald C. 
Published: March 2011

ABSTRACTEarly measurements are reviewed relating to the solubility. the segregation coefficient, diffusion. Internal precipitation, the infrared absorption and the effect on the lattice parameter of silicon due to substitutional carbon. Interactions with oxygen and group III Impurities are mentioned. A survey is given of the effects of high energy irradiation and heat treatments on both FZ and CZ silicon containing carbon. A rich variety of defects can form, but in general atomic structures have not been determined. The process of site switching from substitutional to interstitial locations which occurs by the selective trapping of self-Interstitials is proving to be invaluable in elucidating the mechanisms of various defect reactions, particularly those Involving oxygen Impurities.
Oxygen and Carbon Defect Characterization In Silicon by Sims
Authors: Hockett R. S. , Fraundorf P. B. , Reed D. A. , Wayne D. H. , Fraundorf G. K. 
Published: March 2011

ABSTRACTOxygen and carbon aggregation in silicon after thermal processing can be characterized using SIMS profiles and SIMS imaging. Fluctuations in the oxygen SIMS signal during the profile have been correlated with the change in interstitial oxygen after thermal processing as measured by FTIR and the precipitate size as measured by TEM. In cases where precipitation is known to be the cause of impurity clustering, a computer program for simulating the profiling process allows semi-quantitative characterization of precipitates as a function of depth. The use of a Resistive Anode Encoder on a CAMECA IMS-3f coupled with image enhancement can be used to image oxygen and carbon related defects. Examples of this technique are given by imaging oxygen aggregation and the co-aggregation of oxygen and carbon in thermally-processed Czochralski-silicon.
Carbon Precipitation in Cz and Efg Silicon
Authors: Feng S. Q. , Kalejs J. P. , Ast D. G. 
Published: March 2011

ABSTRACTThe defects formed in carbon rich CZ and EFG silicon after a 900°C, 160 or 560 min long, phosphorous diffusion were studied with TEM. Besides misfit dislocations, numerous precipitates were observed in the junction region in both materials. However, no precipitates were found in the bulk. The precipitates in CZ had a larger strain field than those in EFG material. The difference in the extent of the strain field of precipitates in CZ and EFG silicon can be ascribed to the higher oxygen content in CZ silicon. It appears that oxygen is involved in the Si-self interstitial promoted precipitation of carbon.
Self-Interstitial Injection Effects on Carbon Diffusion in Silicon At High Temperatures
Authors: Ladd L. A. , Kalejs J. P. 
Published: March 2011

ABSTRACTCarbon diffusivity is reported for different ambient conditions imposed during annealing of silicon in the temperature range from 800 to 100°C, which produce varying levels of silicon self-interstitial supersaturation. The diffusivities are deduced from SIMS analysis of carbon out-diffusion profiles. Carbon diffusivity is increased by up to a factor of 70 in annealing with phosphorus in-diffusion, and by a factor of as much as seven in an oxidizing ambient, when compared to anneals in a nitrogen ambient. The enhancements tend to decrease above 11000C. This behavior can be explained by attributing the increase in carbon diffusivity to self-interstitial supersaturation which increases the concentration of highly mobile carbon selfinterstitial pairs. Significant time dependent effects were also observed for 800 and 9000C phosphorus in-diffusion conditions.
Oxygen-Related Defects in Silicon
Authors: Lindström J. Lennart , Svensson Bengt G. 
Published: March 2011

ABSTRACTIn this review we focus on oxygen-related defects created by electron irradiation (vacancy-oxygen defects) and subsequent thermal treatments. The annealing of the vacancy-oxygen pair (VO-center) at 300–350 °C is discussed as well as results from the formation and annealing of the successors to VO, the VO2 and VO3-centers. It -s found that VO2 is formed by diffusion of a vacancy-oxygen pair to an interstitial oxygen atom. It is suggested that VO3 is formed by the diffusion of interstitial oxygen to a VO2-center (in the temperature range 450–485 °C). At continued annealing at these temperatures VO3 is transferred to a new defect VO4 by attaching one more oxygen. Simultaneously thermal donors are developing in a normal way i.e. as in an unirradiated sample. It is therefore concluded that VO2 is not an important core for thermal donors but a possible nucleus for oxygen precipitation.
Electrical Transport Studies of the Hydrogen-Related Compensating Donor in B-Doped Silicon Diodes
Authors: Tavendale A. J. , Williams A. A. , Alexiev D. , Pearton S. J. 
Published: March 2011

ABSTRACTTransport of the hydrogen-related, acceptor-compensating defect has been observed in reverse-bias annealed Al-gate Schottky and n+-P diodes from hydrogenated, B-doped p-Si. Secondary ion mass spectroscopy (SIMS) profiling (deuterium substitution) confirmed field-aided migration. Significant differences in field transport (and thermal diffusion) between diodes from Hand D-treated p-Si(B) qualitatively indicates a monatomic species. The effect is interpreted as field drift of a positively charged species, possibly H+, with a donor charge state in the upper-half band gap, in conflict with long-held theory predicting very deep level activity. Acceptor compensation is unstable under minority (electron) carrier injection by forward bias or illumination at 25°C, supporting the acceptor-protonic trap pair model (A-H+) of Sah, Pan and Hsu [J. Appl. Phys. 57, 5148 (1985)].
Hydrogen Passivation of Oxygen Donors in Si
Authors: Pearton S. J. , Chantre A. M. , Kimerling L. C. , Cummings K. D. , Dautremont-Smith W. C. 
Published: March 2011

ABSTRACTThe electrical activity of the oxygen-related thermal donors in heat-treated, P-doped, Czochralski grown Si is passivated by reaction with atomic hydrogen. Secondary ion mass spectrometry and spreading resistance profiles on deuterium plasma treated samples show a direct correlation between the deuterium incorporation depth and the distance over which the thermal donors are passivated. The donor activity is restored by annealing above 400°C, and comparison with other defect dehydrogenation data suggests that the thermal donors may contain Si dangling bonds. Results obtained from deep level transient spectroscopy measurements are used to illustrate the observed donor passivation and reactivation kinetics.
Channeling Measurements on Deuterium Implanted Silicon
Authors: Nielsen B. Bech 
Published: March 2011

ABSTRACTThe channeling technique has been used to study the lattice location of deuterium ion-implanted into silicon. Compared to earlier measurements by Picraux and Vook, the temperature range has been extended from 30 to 500 K, and the dose has been decreased down to ≃ 8 × 1014 D/cm2. The implantation was performed at 30 K gnd at an energy of 10 keV. The channeling analysis was done using the d(3 He,p)4 He nuclear reaction. Angular scans were measured along the <100>, <110>, <111> axis and the {100}, {110}, {111} planes, Experiments were carried out on the implanted sample (30K) and after annealing to 200 and 500 K. In the as-implanted sample, 80% of the deuterium is located close to the bond center, whereas the remaining 20% is placed at the tetrahedral site. The deuterium sites change after annealing to 200 and 50OK, and the nature of these annealings stages will be discussed.
Redistribution of Ion Implanted Hydrogen in Polycrystalline Silicon Thin Films
Authors: Legge Ronald N. , Brown James F. 
Published: March 2011

ABSTRACTThe effect of implanted hydrogen on the resistivity of polycrystalline silicon films has been investigated. The observed reduction in resistivity due to hydrogen is most pronounced for lightly doped films, and is accentuated by a 450°C anneal. An increase in Hall mobility is also observed. The pre-implant resistivity is completely recovered by annealling at 600°C. Diffusion of hydrogen at low temperatures is monitored by local resistivity changes detected with spreading resistance measurements.
Variations in the Refractive Index of the Near-Surface Region of Low Energy Hydrogen Ion Bombarded Silicon
Authors: Pettit R. B. , Panitz J. K. G. 
Published: March 2011

ABSTRACTUsing ellipsometric analysis, the complex index of refraction of lowenergy, hydrogen ion bombarded, [100] single-crystal silicon was measured as a function of distance from the bombarded surface. The bombardment conditions were a 1600 eV hydrogen beam produced by a Kaufman ion source, 1.4 mA/cm2 flux, 2 × 1018 ions/cm2 fluence and 275°C bulk silicon temperature. These conditions are comparable to the conditions generally reported to result in a substantial increase in the electrical conductivity of polycrystalline silicon solar cell material. The results of this study indicate that the real and imaginary parts of the refractive index of the ion bombarded surface region approach that of the unbombarded substrate at a depth of 50 nm. The refractive index of about the first 10 nm of ion bombarded material is strongly dependent on the bombardment conditions. Variations in the imaginary part of the refractive index indicate that approximately 10% of incident radiation is absorbed by the first 50 nm of modified material.
Nitridation Induced-Reactions in Si and SiO2
Authors: Jaccodine Ralph J. 
Published: March 2011

ABSTRACTCurrent IC technology uses SiO2 almost exclusively; however, several technological and reliability problems warrant the search for an alternative dielectric. Proposed alternatives are silicon nitride and nitrided SiO2. This paper reviews the work on thermal nitridation of Si and SiO2. Several of the experimental thermal nitridation processes used to achieve good thin dielectrics are discussed. At this time a clear mechanism for the nitridation of Si is not available. The two theoretical attempts to model this process are reviewed. Innovative processes to accomplish the nitridation, such as plasma growth, etc., are presented. Finally, the influence of nitridation on stacking faults and diffusions is also reviewed.