bluuebunny/crossref_metadata_2025_split huggingface dataset:
Silicon Quantum Wires Oxidation and Transport Studies
Authors: Liu H. I. , Biegelsen D. K. , Johnson N. M. , Ponce F. A. , Maluf N. I. , Pease R. F. W. 
Published: March 2011

ABSTRACTFabricating well controlled nanostructures and obtaining precise structural, electrical, and optical information from them are essential for understanding die intrinsic properties of silicon (Si) nanostructures, which in turn is important for exploring the potential of quantum confinement induced light emission from crystalline Si. A combination of high resolution electron beam lithography, anisotropic reactive ion etching (RIE), and thermal oxidation has been successfully applied to obtain sub-5 nm Si columnar structures [1]. A transmission electron microscopy (TEM) technique has also been used to characterize die precise structural dimensions of these columns [1]. To obtain the electrical and optical information, a process based on polyimide planarization was developed to establish electrical contacts to these nanostructures. The same process is also applicable for fabricating device structures to study electrically pumped optical response. Preliminary transport studies have confirmed current conduction through die Si nano-pillars and yielded an estimate of die conductivity.
Electroluminescence as a Function of Electric Field and Temperature in Amorphous Silicon-Carbon Based p-i-n Structures
Authors: Pevtsov A. B. , Pilatov A. G. , Feoktistov N. A. , Zherzdev A. V. , Karabanov S. M. , Muschik T. , Zrenner D. , Schwarz R. 
Published: March 2011

ABSTRACTElectroluminescence at room temperature with a peak energy between 1.6 and 1.8 eV is observed in a-SiC:H p-i-n devices containing thin injection layers of high bandgap a-SiC:H. The temperature dependence of electroluminescence between 80 K and 320 K is much weaker than expected from the photoluminescence signal. No shift of the electroluminescence spectrum is observed up to voltages of 20 V applied across a 110 nm thick device. The results are compared to well-known features of electroluminescence in a-Si:H devices.
Effects of Diluted-Hydrogen and Hydrogen-Atom-Treatment on the Silicon-Hydrogen Bonding Configurations of Hydrogenated Silicon Films
Authors: Hsu K. C. , Chang H. , Hwang H. L. 
Published: March 2011

ABSTRACTThe silicon—hydrogen bonding configuration studies of hydrogenated silicon films that were fabricated by diluted—hydrogen and hydrogen—atom—treatment methods are presented. The diluted—hydrogen samples tend to show a very sharp line—shape in the NMR spectra as the H2/SiH4 dilution ratio is increased and/or temperature is elevated. The addition of atomic hydrogen treatment can produce the same NMR spectra at a temperature lower than 200°C. The Raman scattering spectra show that the μc—Si phase can be formed by the atomic hydrogen treatment. The infrared absorption spectra also indicate an increase of SiH2 bonding configuration and a hydrogen content reduction when atomic hydrogen treatment is employed. These results suggest that the degree of crystallinity of hydrogenated silicon films can be systematically adjusted.
Micro-Crystalline Silicon in Image Sensor
Authors: Park B. W. , Choi J. I. , Hur C. W. , Oh T. K. , Kang I. K. 
Published: March 2011

ABSTRACTAmorphous semiconductors play a major role in the field of electronic imaging. The function of an image sensor is to generate an electrical signal corresponding to the light distribution in the optical image. The photodiodes convert light into electrical signal. We investigated the linear image sensor driven by thin film transistor as an switching element, with each photodiode connected to the corresponding thin film transistor. The photo/dark conductivity of photodiode are compared in the case of amorphous silicon and microcrystalline. The influences in contact resistance between microcrystalline n+ layer and the source/drain metal electrode, electron mobility, threshold voltage, and on-off current ratio of thin film transistor with intrinsic microcrystalline silicon channel layer were also investigated.
Growth of Polycrystalline Silicon films at low Temperature by Remote Plasma CVD
Authors: Chul Kim Sung , Chang Park Kyu , Ki Kim Sung , Mok Jun Jung , Jang Jin 
Published: March 2011

ABSTRACTWe studied the growth of polycrystalline silicon by using remote plasma chemical vapour deposition technique. The effects of RF power and the substrate temperature on the structural properties have been investigated. With increasing the RF power, the crystalline volume fraction and the grain size increase up to 100W, but decrease for the further increase in power level. We obtained the poly-Si with the crystalline volume fraction of about 74 at.% at the substrate temperature of 330°C.
Early Stage in Polycrystalline Growth of Si by Fluoro-Oxidation of Silane
Authors: Endo Kenji , Bunyo Masahiro , Shimizu Isamu , Hanna Jun-Ichi 
Published: March 2011

ABSTRACTWe have studied the polycrystalline growth of Si prepared by a reactive gas flow of SiH4 and F2. In a very early stage of the film growth on the amorphous substrates, a thin layer of the amorphous phase was deposited even in the favorable condition for the crystal growth, whose thickness was determined by the growth condition and reached to 200–300nm in a certain condition. The crystalline phase consisted of closely packed small grains perpendicular to the substrate, 200–500nm in diameter, each of which displayed a tooth-like shape with fine structures, indicating a formation of the crystal nuclei in the amorphous phase and their growth to the grains. The generation probability of the nuclei was not uniform in the amorphous phase, high at the region far from the substrate, and very sensitive to the growth temperature, judging from cross sectional TEM micrographs of the films. These suggest that the network propagation of Si in which fluorine, participates the chemical process in the vicinity of the growing surface enhances a formation of the long range ordering in the network, resulting in the generation of the crystal nuclei.
Deposition of Polycrystalline Silicon thin Films by Plasma Enhanced CVD
Authors: Hollingsworth Russell E. , Bhat Pawan K. 
Published: March 2011

ABSTRACTPolycrystalline silicon films have been grown using high frequency (110 MHz) rf plasma enhanced chemical vapor deposition with a hydrogen diluted silane gas. Polycrystalline growth was obtained when the silane fraction was less than 10% of the total gas mixture for all rf powers, in marked contrast to growth at 13.56 MHz where high power and more dilution are typically required for microcrystalline growth. Grains with [111] and [220] orientations were observed to have grain sizes up to 900 Angstroms. Room temperature free carrier concentrations as low as 5 × 1015 cm-3 for undoped films were determined by capacitance voltage measurements. Boron doped microcrystalline films were grown with conductivity as high as 8 (Ωcm) V
A New Annealing Method to Obtain High Quality Poly-Si
Authors: Song Yoon-Ho , Baek Jong-Tae , Nam Kee-Soo , Kang Sang-Won 
Published: March 2011

ABSTRACTA new annealing method, a combination of rapid thermal annealing (RTA) and furnace annealing, has been developed to obtain a high quality poly-Si from a-Si deposited by LPCVD. This method produces a large grain poly-Si with good uniformity, which may result from the growth of relatively defect-free nucleus generated at a high temperature by RTA. Poly-Si thin film transistors fabricated by this new annealing method have higher field effect mobility and better uniformity compared with those by the conventional furnace annealing.
Heterogeneous Reactions of GaAs Quantum Dots with Organometallic Precursors
Authors: Saunders Winston A. , Lee Robert B. , Atwater Harry A. , Vahala Kerry J. , Flagan Richard C. , Sercel Peter C. 
Published: March 2011

ABSTRACTWe report recent results on the homogeneous nucleation of GaAs quantum dots from organometallic precursors and subsequent heterogeneous nucleation of epitaxial regrowth of GaAs on the clusters. We find that clusters onto which we have regrown GaAs exhibit a much higher degree of faceting, whereas particles subject to che same thermal cycles but onto which no new GaAs has been grown, though crystalline, have highly irregular shapes. These results suggest that epitaxial regrowth exhibits selectivity in the growth rates on the various crystal facets akin to that found in bulk samples.
Growth of GaAs Epitaxial Microcrystals on a S-Terminated GaAs (001) by Vls Mechanism in MBE
Authors: Koguchi Nobuyuki , Ishige Keiko , Takahashi Satoshi 
Published: March 2011

ABSTRACTNumerous GaAs epitaxial microcrystals having nearly equal size were fabricated on a S-terminated GaAs(001) surface by a sequential supply of Ga and As molecular beams. The GaAs(001) surface was terminated by sulfur atom in the MBE chamber. The growth of GaAs epitaxial microcrystals is caused by a Vapour-Liquid-Solid(VLS) mechanism. GaAs epitaxial microcrystals were also fabricated on a S-terminated GaAlAs(001) surface by the same procedure.
Composite Semiconductor Nanoparticles
Authors: Zhou H. S. , Honma I. , Komiyama H. , Haus J. W. 
Published: March 2011

ABSTRACTNanometer size semiconductor particles coated with another semiconductor can exhibit unusual and interesting phenomena associated with the redistribution of the electron and hole wavefunctions. Using the band offsets and effective-masses, the band gap as well as the wavefunctions can be altered by changing the core radius of the particles. CdS/PbS coated semiconductor nanoparticles are synthesized by ion displacing method and experimental results are discussed along with the theoretical calculation. Optical absorption as well as TEM, Electron diffraction results provides for the evidence that the particles are coated.
TEM Investigation of Si/βFeSi2/Si (100) and (111) Heterostructures Formed by Fe Implantation
Authors: Bulle-Lieuwma C. W. T. , Oostra D. J. , Vandenhoudt D. E. W. 
Published: March 2011

ABSTRACTSi/βFeSi2/Si (100) and (111) structures were obtained by implantation of 450 keV Fe+ ions with a dose of 6×1017 Fe+ ions/ cm2 into Si substrates. A continuous buried βFeSi2 layer with thickness of 250 nm was formed during subsequent annealing. By transmission electron microscopy it has been found that for (100) Si the layer consists of βFeSi2 grains with lateral dimensions of approximately O.5 μm and for (111) Si of grains of 5 μm in size. The βFeSi2 films exhibit a high degree of epitaxy with the Si substrate. A detailed structural examination shows the occurrence of several epitaxial relationships of βFeSi2 with the Si substrate. In contrast to two-dimensional surface growth techniques, the formation of a buried layer by implantation occurs by a three-dimensional growth process by the coalescence of βFeSi2 precipitates. The different orientations of the βFeSi2 grains in the buried layer are already established by the orientation of the precipitates formed during implantation.
Raman Scattering Study of Boron Doped Diamond Synthesized at High Pressure
Authors: Shiomi Hiromu , Kirillov Dimitry , Hagstrom Stig B. 
Published: March 2011

ABSTRACTBoron doped diamond synthesized at high pressure was studied using Raman scattering. Shift and broadening of the diamond phonon line was observed and attributed to disorder produced by boron doping. Electronic transitions within boron acceptor states and Fano-type interference between phonons and the electronic continuum have also been observed in the spectra.
Silicon Nitride Deposited at Very Low Silane Pressures Using Electron Cyclotron Resonance Plasmas
Authors: Flemish J. R. , Pfeffer R. , Buchwald W. , Jones K. A. 
Published: March 2011

ABSTRACTWe report on the material properties of SiNx:H films deposited using a 2% SiH4/N2 mixture with additional N2 in an ECR reactor. Deposition rates, refractive index, and stoichiometry have been characterized using ellipsometry, Rutherford backscattering spectroscopy, and infrared spectroscopy. Reactor conditions of 2m Torr total pressure, 650W microwave power, and substrate temperature of 250°C result in high quality, stoichiometric silicon nitride. With a SiH4/N2 ratio = 0.003, hydrogen incorporation is approximately 1.5% and the refractive index is nr =2.0. Lower microwave power and a higher SiH4/N2 ratio result in slightly N-rich films which is attributable to increased H-incorporation. Higher total pressure results in significantly enhanced deposition rates, but with greatly increased H and O content.
Effect of Silicon Surface Treatments on Thin Silicon Nitride Growth
Authors: Nakamura Makoto , Kikuchi Yoshio , Kuwamura Masahiro , Yoshida Masamichi 
Published: March 2011

ABSTRACTUltra thin silicon nitride films have been indispensable in high density memory devices as a dielectric. We investigated the effect of the silicon surface state on initial silicon nitride growth process, we have used X-ray Photoelectron spectrometry (XPS), Secondary ion mass spectrometry(SIMS), and Capacitance-Voltage(C-V) characteristics. The results of our study show that the fluorine on silicon surface influences initial silicon nitride growth. The presence of fluorine delays low pressure chemical vapor deposition(LPCVD) silicon nitride growth as well as restraining native oxide growth at the silicon nitride/silicon substrate interface. We propose that it is a key process of thin dielectric films deposition to control fluorine on silicon surface.
Digital Chemical Vapor Deposition of Silicon Oxide/Nitride and its Surface Reaction Study
Authors: Sakaue H. , Nakasako T. , Nakaune K. , Kusuki T. , Miki A. , Horiike Y. 
Published: March 2011

ABSTRACTIn order to fill high quality insulators into narrower spaces in advanced metallizationthe digital CVD (Chemical Vapor Deposition) of multilayer stacked Si oxide and nitride films was studied. Reaction of TES (triethylsilane) with hydrogen (H) atoms was also found to lead to conformal CVD of Si film involving organic species. This reaction took place only on the surface reaction. In-situ FTIR studies reveal that H atoms react with Si-C2H5 bonds in TES and thus generate strong Si-CH3 bonds and weak Si-H bonds, thereby liberating H2 and forming the organic Si film on the surface, and the surface reaction is dominated by the thermal effect from the substrate. Then Si oxide or nitride films were formed by the digitaCVD which repeated a cycle of deposition of this film with subsequent oxidation or nitridation. Oxide film integrity was improved greatly by removing included organic bonds in the TES/H reaction film by exposing the film to H atoms before the oxidation step. Thus electrically excellent multilayer stacked oxide and nitride films were obtained in a deep trench.
Influence of Ion Energy in Plasma Deposition of a-Sio2 Films
Authors: Vallier L. , Joubert O. , Burke R. , Ferrieu F. , Devine R. A. B. 
Published: March 2011

ABSTRACTSilicon dioxide films have been deposited using a microwave plasma of (SiH4 + O2) excited by distributed electron cyclotron resonance. The ratio of flow rates of the reactive gas was (O2: SiH4) = 7 and no intentional substrate heating was used. The effect of ion energy during deposition, in the 10 — 150 eV range, has been studied through refractive index, infrared absorption bands, chemical etch rate and electrical measurements. It is found that for an ion energy > 50 eV, many of the film characteristics are close to those of thermal SiO2.
Transient Flat-Band Voltage Shifts Following High Voltage Stressing of Thin Oxides
Authors: Wong D. P. , Dumin D. J. 
Published: March 2011

ABSTRACTIt has been shown that the transient decay of the current after removal of a high voltage stressing pulse changed from an exponential RC time constant decay to a very long decay that had a 1/t time dependence[l]. During these long transients the flat-band voltages of the capacitors changed as the traps inside the oxides discharged. The discharge of both positive and negative changes near the silicon-oxide interface have been measured using QSCV measurements. In this paper the transient shifts in the flat-band voltages due to the discharging of stress generated traps in the oxide will be described.
Pump-Probe Charge Integrating Investigation of Trap Emission Kinetics in Ultrathin Mos Capacitors
Authors: Poler J. C. , Irene E. A. 
Published: March 2011

ABSTRACTAs design rules shrink to conform with ULSI device dimensions, gate dielectrics for MOSFET structures are required to be scaled to even thinner proportions. Upon scaling the gate oxides below ∼60Å the interfacial region becomes a significant proportion of the total film. Thus interface properties are weighted more heavily in determining device performance and reliability.We have developed a Pump-Probe charge integrating measurement technique for studying the emission kinetics of traps in the M/SiO2/Si system. Essentially, a MOS capacitor is pumped by exposure to a charging pulse. The emission of the charge at short time scales (<10ms), can be measured using a delayed application of a probe pulse which determines the remainder of the filled traps as a function of delay time. For a lightly doped p-Si (lll) substrate, we observe an uncommon behavior of the emission kinetics in the initial time regime (< 100ms). A possible explanation for this phenomenon is the perturbation of the emission cross-section of the probed traps due to the presence of another state in communication with the trap site.
Defects Induced by Electron Bombardment and Substrate Doping in SiO2 Thin Films
Authors: Xiong-Skiba P. , Carroll D. L. , Doering D. L. , Siek K. H. 
Published: March 2011

ABSTRACTThin SiO2 films grown on silicon substrates were exposed to electron beam irradiation at energies from 100 eV to 2.5 KeV. Then, thermally stimulated exoelectron emission (TSEE) spectra were taken by heating the sample linearly to a maximum temperature of 600°C. We have compared the emission behavior from oxides grown on both n-typeand p-type, (100) and (111) silicon wafers. The TSEE spectra show emission peaks whichcan be categorized by their behavior into two groups. The β emission peaks are characteristic of emission from localized electron traps while the γ emission peaks result from the annealing of beam-induced defects. We have observed changes in the β peaks which appear to be associated with the concentration of dopants in the substrate material. In addition, we have identified a beam energy threshold near the oxygen Is binding energy for the creation of defects. This suggests that defect creation results froman electronic transition similar to electron stimulated desorption.
Thermal Annealing of Radiation-Induced Trapped Charge in Simox and Thermal Oxide Thin Films
Authors: Herve D. , Paillet Ph. , Leray J. L. 
Published: March 2011

ABSTRACTThe results of charge trapping and thermal annealing in X-ray irradiated SiO2 are presented. A comparative study is made between thermal oxide and SIMOX buried oxide behavior. At low dose (10 krad(SiO2)), X-ray induced charge trapping is found to be very different in thermal and SIMOX oxides. Results are interpreted in terms of a relatively large bulk trapping in SIMOX whereas thermal oxide behavior is dominatedby interface trapping. However, at high dose, both oxides behave similarly and are dominated by interface trapping. Etch-back experiments performed on SIMOX irradiated at 10krad (SiO2) and 1 Mrad (SiO2) reveal these two trapping regimes. Isochronal annealings have been performed up to 300°C on irradiated samples. Recovery data are interpreted assuming an energy distribution of trapped charge densities. Detrapping energies located at about 1.05 eV and 1.35 eV have been obtained in SIMOX whereas the thermal oxide exhibits a unique peak at 1.35 eV. Based on these data, SIMOX and thermal oxides are demonstrated to differ significantly.
Evidence for Low Temperature UV Annealing of UVCVD, PECVD and Sog Based SiO2 Films
Authors: Debauche C. , Devine R. A. B. , Licoppe C. , Flicstein J. , Huet F. 
Published: March 2011

ABSTRACTUltraviolet radiation has been used to anneal out extrinsic defects in several types of deposited a-SiO2 films. The UV light was obtained from a new krypton UV-VIS-IR lamp with a spectral range of 170 nm <λ<3μ This “cold” annealing was performed on a-SiO2 films, with various thicknesses up to 400 nm. The films were deposited by various techniques, ultraviolet induced chemical vapour deposition (UVCVD), plasma enhanced vapour deposition (PECVD) and spin-on-glass (SOG). Fourier Transform Infra-Red spectroscopy (FTIR) and Electron Spin Resonance (ESR) were used to characterize the effect of the radiation. In the case of UVCVD and SOG a-SiO2 films, it is shown that the UV radiation removes the Si-H bonds and reduces significantly the amount of C-H and C-H3 groups. In both these films, an important reduction in the amount of adsorbed water and Si-OH groups is observed, together with an increase in the number of Si-O bonds. In PECVD films made with tetraethylorthosilicate (TEOS) vapour and O2 as precursor gases, we find evidence for an important reduction in the amount of C and the number of Cn Hy related defects. The UV treatment is effective even at temperatures as low as 100 °C, which suggests that it could constitute a much needed low temperature annealing step.
Silicon and Nitrogen Dangling Bonds Point Defects in PECVD Silicon Oxynitrides Thin Layers
Authors: Viscaino S. , Cros Y. , Ruf B. 
Published: March 2011

ABSTRACTNew defects were revealed in PECVD SiOxNyHz thin layers upon VUV-illuminations with a deuterium (De) lamp. The ESR signal measured after a 8-hour illumination reached a saturated amplitude one or two decades higher than the dark ESR signal. The dark ESR signal level was recovered after a 3-hour anneal at 380°C. In addition to the silicon dangling bonds already identified in the dark ESR, the bridging nitrogen dangling bonds and over-coordinated nitrogen were identified after VUV-radiations. The relative densities of the various kinds of defect are given as a function of the O/O+N oxynitride composition.
Silicon-Nitride for Amorphous Silicon Thin-Film Transistors
Authors: Nickel N. H. , Fuhs W. , Mell H. , Beyer W. 
Published: March 2011

ABSTRACTNitrogen-rich amorphous silicon-nitride films a-Si1−xNx:H were prepared by glow-discharge decomposition of gas mixtures of ammonia and silane. With increasing nitrogen content the spin density, Ns, decreases from 4×1018cm−3 (x = 0.55) to 3×1017cm−3 (x = 0.67). These films were used as a gate dielectric in amorphous silicon TFTs. The TFTs are characterized by measurements of the transfer characteristics and by a transient current spectroscopy (TCS). Nitrogen-rich dielectrics with Ns<1018cm−3 have little influence on the transfer characteristic, however, they tend to have a lower sensitivity to bias stress. Using a device-quality nitride (x = 0.64) the properties of the TFTs were varied in two ways: 1) doping of the a-Si:H film with phosphine or diborane and 2) exposure of the nitride film to an oxygen plasma. The variation of the areal density of defect states, Nd, with Ec-EF suggests that the effective density of interface states, Ni, and the characteristic of undoped TFTs are determined by interface defects of the a-Si:H film. The plasma treatment introduces oxygen into a thin superficial layer of the nitride. By varying the exposure time te it is possible to change the properties of the TFTs continuously from nitride like to oxide like.