bluuebunny/crossref_metadata_2025_split huggingface dataset:
Light-Induced Effects in a-Si:H Films and Solar Cells
Authors: Uchida Yoshiyuki , Sakai Hiroshi 
Published: March 2011

ABSTRACTThe present state of a-Si:H solar cells and studies on the light-induced effects in a-Si:H films and a-Si:H solar cells are presented. The conversion efficiencies attained are 11.5%, 10.1% and 7.5% (8.5% in active area) for 1.0cm2 singlejunction, multijunction cells and 1200cm2 submodule, respectively. The density of light-induced defects, ANs, changes with deposition temperature and annealing temperature. This suggests a strong correlation between the ANs and the network structure in a-Si:H films. Field testing results indicate that the degradation of a-Si:H modules can be suppressed within 10% of the original efficiency after 2 years operation. It is also indicated that the multijunction cells are more stable to light exposure than single p-i-n cells.
Stability of Amorphous Silicon Solar Cells — New Tandem a-SiC/a-Si Solar Cell
Authors: Tawada Y. , Takada J. , Yamaguchi M. , Yamagishi H. , Hosokawa Y. , Hiroe A. , Kondo M. , Asaoka K. , Fukada N. , Tsuge K. 
Published: March 2011

ABSTRACTBasic technologies for solving problems in thermal and light-induced degradation have been developed. The tandem type a-SiC/a-Si solar cell with blocking layers exhibits excellent stability for both thermal and sun light conditions. An observable light-induced degradation is not seen in the cell performance after light exposure test of 2000 hours. Two instability modes, that is, thermal and light-induced degradation have been investigated. For thermal degradation, a blocking layer for preventing diffusion has been inserted between the back side metal electrode and a n-layer and another blocking layer has been introduced between the np tunnel junction. To prevent light-induced degradation, p-type a-SiC layer of the pin structure on the side of a glass substrate/SnO2 has been deposited at the temperature of 70°C. The highest efficiency is 9.0% at the present stage, but it is expected to be improved to more than 10%.
The Materials Issues and Applications of Amorphous Silicon Thin Film Transistors
Authors: Thompson M. J. 
Published: March 2011

ABSTRACTRecently considerable interest has been generated in the application of thin film transistor (TFT) technology in electronic input and output devices. Amorphous silicon (a-Si:H) has made a major impact in these applications because of the relative ease with which the material can be economically manufactured over large areas. This paper will review in particular the current status of a-Si:H TFTs in liquid crystal display and printer applications, in addition to sensor/TFT arrays for page width input scanner document readers. There are a number of materials issues which limit the performance of these devices. In addition, there are some technological issues which influence the yield of the processes used to fabricate these electronic devices over large areas. Some novel new devices have been recently developed which dramatically increase the operating voltage of a- Si:H TFTs. Other new structures have been proposed and demonstrated for increasing the current and speed of these devices.
Electrophotographic Properties of n+-a-Si:H/a-Si:H/a-Sic:H Heterostructures
Authors: Paasche S. M. , Bauer G. H. 
Published: March 2011

ABSTRACTFor negative charging electrophotographic applications a three layer heterostructure (Al/n+-a-Si:H/a-Si:H/a-SiC:H) has been investigated. To some extent a separation of the function of charge storage by a high band gap amorphous silicon carbon alloy and of that of photogeneration of carriers and of sufficient photosensitivity in an intrinsic amorphous silicon film has been achieved. Due to a low injection of electrons from the surface into the a-SiC:H and a small thermal generation rate of carriers within the a- Si:H film, the dark decay of the negative surface potential is dominated by space charge limited currents of holes. Thus a considerable difference in surface potential for negative and positive charging occurs, which is related to the difference in electron and hole mobility in a-Si:H. Since there is no remarkable barrier at the heterointerface a-Si:H/a-SiC:H an excellent injection of photogenerated holes into the a-SiC:H can be provided.
A-SI:H Image Sensors: Some Aspects of Physics and Performance
Authors: Rosan K. , Brunst G. 
Published: March 2011

ABSTRACTHigh photosensitivity and fast photoresponse have proved a-Si:H to be a suitable thin-film photoconductor for large-size linear image sensors. Besides the a-Si:H bulk properties, the a-Si:H/electrode interfaces are of major influence on the sensor performance. In view of this performance, the readout circuit has to be designed carefully with respect to the desired dynamic range. Care has to be taken to avoid electrostatic hazards when mounting the sensor, as the breakdown voltage of a-Si:H sensor elements was found to be about 60 volts.
Influence of Unsymmetrical Electrode structure on a-Si Photodiode Characteristics
Authors: Hayama M. , Kobayashi K. , Miki H. , Onishi Y. 
Published: March 2011

ABSTRACTAmorphous silicon(a-Si) stripe p-i junction photodiode array for contact-type image sensor of a facsimile has been developed and investigated especially with regard to its unsymmetrical electrode structure. This sensor consists of a p-i a-Si stripe layer, Cr separate electrodes, and an ITO common electrode. As a result, it is found that the photosensitive region of a-Si stripe type photodiode exists not only in a-Si sub-region having both upper and lower electrodes but also in a-Si sub-regions having upper or lower one-sided electrode. It is considered that photocarrier collecting mechanisms in the a-Si sub-regions are different and result to the different photodiode characteristics.
Multiple Quantum NMR Study of Hydrogen Clustering in Amorphous Silicon
Authors: Gleason Karen K. , Baum J. , Garroway A. N. , Pines A. , Reimer J. A. 
Published: March 2011

ABSTRACTBecause Multiple Quantum NMR coherences occur only between spins which are coupled together by the dipole interaction, this technique has been used to study the clustering of hydrogen in amorphous silicon. The clustered hydrogen was found to be associated with the broad line of the single quantum NMR spectra. For device quality films, the average cluster size is approximately six protons. The concentration of these five to seven atom defects increases with increasing hydrogen content until, at very high hydrogen content, the clusters are replaced by a continuous network of silicon-hydrogen bonds.
Annealing Effects on Deuterium in a-Si:D.
Authors: Bork V. P. , Fedders P. A. , Leopold D. J. , Norberg R. E. , Boycea J. B. , Knights J. C. 
Published: March 2011

ABSTRACTProgressive annealing of a-Si:D and a-Si:DH samples between 250 and 600°C is found to eliminate the broad central deuteron magnetic resonance (DMR) spectral component associated with weakly bonded D. The well-resolved doublet arising from tightly bound D diminishes in intensity. The narrow central line associated with microvoid-contained molecular D2 and HD increases and then decreases for the warmest anneals. DMR relaxation times, line shapes, and hole-burning spectra reflect changes in sample morphology upon annealing.
Growth of GeSi/Si Strained-layer Superlattices Using Limited Reaction Processing
Authors: Gronet C. M. , King C. A. , Gibbons J. F. 
Published: March 2011

AbstractSiGe/Si superlattices were grown using limited reaction processing in a chamber which allows both W-halogen and Hg arc wafer illumination. Each multilayer structure was fabricated in-situ by changing the gas composition between high temperature cycles. Commensurate SiGe alloy layers as thin as 15 nm were reproducibly deposited and were examined using transmission electron microscopy, sputtering Auger electron spectroscopy,and Rutherford backscattering. Preliminary results are presented on UV/ozone cleaning of LRP substrates to remove residual carbon contamination in-situ prior to film deposition.
Epitaxial Growth of Silicon Using Photochemical Vapor Deposition at a Very Low Temperature of 200º Centigrade
Authors: Konagai M. , Nishida S. , Yamada A. , Shiimoto T. , Karasawa S. , Takahashi K. 
Published: March 2011

AbstractA new technique for silicon epitaxial growth has been developed using mercury—sensitized photochemical vapor deposition (photo—CVD). Epitaxial thin layers were grown on (100) Si substrates at 100–300ºC from a gas mixture of Si2H6+AiH2F2+H2 by irradiation of a low pressure mercury lamp (1849A, 2537A). Refiective high energy electron diffraction (RHEED) and Raman scattering measurements showed that the epitaxial layers had good crystallinities.The epitaxial layers were characterized by secondary ion mass spectroscopy (SIMS) and the van der Pauw Hall2 measurements. The undoped Si layer showed the electron mobility of 520cm2/Vs with a carrier concentration of 3.2xl04cm
Slant-Scanning and Interstice-Bridging Applied to ZMR to Improve the Quality of Recrystallized Si Films on Quartz
Authors: Tomita Hisashi , Kojima Shigeru , Usui Setsuo 
Published: March 2011

AbstractCMOS test circuit chips have been fabricated for the purpose of evaluating Si film recrystallized on quartz wafers by using a graphite-strip heater oven equipped with a micro-computer feedback system. Two new methods have been applied to the zone-melting recrystallization technique to produce a highly uniform and grain boundary (GB) free recrystallized Si film. The slant-scanning method was used to control the GB's location in recrystallized Si film of 180μm wide stripes separated by 20μm. The intersticebridging method was used to reduce the (111) texture generation to less than 1%. The average electron mobility and the average threshold voltage for MOSFET's were 960cm2/V sec, with a standard deviation of 43cm2/V sec, and 1.38V with a standard deviation of 0.25V, respectively. For the ring oscillator, at a supply voltage of 12V, the propagation delay time was 1.7nsec per stage. The maximum response frequency was higher than IMHz for the CMOS inverters.
Submicron Highly Doped Silicon Epitaxial Layers Grown by Lpvpe
Authors: Vescan L. , Beneking H. , Meyer O. 
Published: March 2011

AbstractBy low pressure vapour phase epitaxy (LPVPE) epitaxial growth down to 760ºC has been achieved in the SiC12H2/H2 system, as revealed by RBS and channeling measurements ( min ∼4.0%). High and relative homogeneous doping was obtained with boron resp. phosphorus in the range 1x1018 -5x1019 cm-3 for T: 800º - 900ºC. Sharp transitions in the boron doping profile to the substrate, of the order of 15mn, result only for temperatures much lower than 850ºC. Schottky barrier enhanced diodes with promising performances were formed with Ti evaporated on p+n layers grown selectively on n+ substrates.
Defect Reactions and Atomic Diffusion in Silicon
Authors: Pantelides Sokrates T. 
Published: March 2011

AbstractAtomic diffusion is generally mediated by intrinsic defects such as vacancies and self-interstitials. In this paper we give a critical review of the relevant properties of intrinsic defects in Si as they have been determined by experiments and recent theoretical calculations. We then review the role of these defects in mediating self-diffusion and dopant impurity diffusion both under equilibrium and non-equilibrium conditions. A systematic and internally consistent picture emerges, but many processes, such as oxidation-modified and nitridation-modified diffusion require more systematic data for detailed understanding.
Electrical Characteristics of Silicon p+n Diodes Fabricated BY B+ Implantation and Rapid Thermal Annealing in the Temperature Range 700 - 1000°C
Authors: Usami Akira , Katayama Masayuki , Tokuda Yutaka , Wada Takao 
Published: March 2011

AbstractB+ implanted p+n diodes were fabricated by rapid thermal annealing (RTA) in the temperature range 700 - 1100°C. Values of series resistance of diodes decreased with the annealing temperatures. Leakage current (Ir) was independent of the RTA temperatures. Residual defect concentrations increased in the range 700 - 900°C and decreased in the range 1000 - 1100°C. Concentrations of defects with the energy levels of Ec- 0.33 and Ec - 0.48 eV were ∼ 1012 cm−3 for diodes fabricated at 1100°C. The growth of defects in the range 700 - 900°C was ascribed to the diffusion of defects from the implanted layer during annealing.
Low Pressure Chemical Vapor Deposition of Tungsten and Aluminum for VLSI Applications
Authors: Levy R. A. , Green M. L. 
Published: March 2011

AbstractThis paper reviews the current status of LPCVD tungsten and aluminum for VLSI applications. Using deposition chemistries based on tungsten hexafluoride and tri-isobutyl aluminum, W and Al deposits are characterized with respect to their electrical, mechanical, structural, chemical and optical properties. Although results of this study prove these two LPCVD processes to be compatible with current VLSI fabrication, certain problems must still be resolved for complete commercial acceptance. These problems include, in the case of selective LPCVD tungsten, the occurrence of leakage current across N+/P-Tub junctions, and in the case of LPCVD aluminum, the relatively poor electromigration resistance (compared to Al-Cu) and excess surface roughness.
Characteristics of Electromigration in Aluminum Interconnect Lines for Integrated Circuits
Authors: Schreiber H.-U. 
Published: March 2011

AbstractReliability of Al metallization is strongly influenced by electromigration. In Al lines there are at least two competing failure modes. On the one hand, mass flow divergencies can produce stripe interruptions, and on the other hand, homogeneous mass flow, which is described by the Al drift velocity, can lead to contact openings. Test results indicate that the drift velocity limits the lifetime of metallization. Worst case failure behavior should be measured in long test lines, since there is an electromigration threshold, which affects mass flow in shorter lines. Al reliability can be improved by reducing the total mass flow.This might be done by influencing electromigration mechanisms. Considering electromigration threshold, grain boundary and interface electromigration can be eliminated in large-grained, narrow lines. The extremely low mass flow of the remaining mechanism is beneficial for the reliability of metallization.
Gettering In Silicon
Authors: Seidel T. F. 
Published: March 2011

AbstractThis paper reviews the basis for phenomenological path for gettering: release, diffusionand capture in the context of old and new developments. More recent precipitation studies in silicon are now recognized to involve complex interactive effects. Controlled precipitation requires knowledge of and control of not only oxygen but carbon, native defects(related to crystal thermal history and/or process history), high doping, microfluctuations and interactions between “extrinsic” and “intrinsic” gettering.
Mo/Cr Metallization for Silicon Device Interconnection
Authors: Kim M. J. , Saia R. A. 
Published: March 2011

AbstractA molybdenum and chromium double layer contact has been developed for the first level metallization of VLSI circuits. An 800Å layer of chromium deposited under a thick molybdenum conductor provides good ohmic contact to p+ and n+ silicon and also promotes metal adhesion to the substrate. The molybdenum has good step coverage and acceptable current carrying capacity when its thickness exceeds 5000Å. Both metals are sequentially sputtered in one pumpdown and patterned with a single RIE step using CCI4 + O2. One pm diameter contacts and 1.5µm wide lines are formed in VLSI geometries using all dry etch processes. Electrical characteristics and thermal reliability were evaluated as a function of annealing temperature. Contact resistance and shallow device junctions are stable up to 500°C for p+/n diodes and up to 450°C for n+/p diodes. The sheet resistance of the film in contact with silicon rapidly increases at 525°C as silicon outdiffuses to form (Mox Crr−x)Si2 The mechanism and cause of the high temperature degradation was studied by mean of SIMS, x-ray diffraction analysis, SEM and electrical measurements.
Infrared Absorption Study of Porous Silicon
Authors: Harwood P.B. , Thomes G.P. 
Published: March 2011

AbstractData is presented which links the 620 - 660 cm−1 infrared absorption doublet in porous silicon films to the presence of silicon hydride. This band assignment explains both the magnitude and thermal behavior of the doublet, and is in agreement with published data on silicon hydrides.
The Properties Of Phosphorus In Polycrystalline Silicon - A Nuclear Magnetic Resonance Study
Authors: Mccarthy Michael J. , Meyerson B. , Karim M. S. , Reimer J. A. 
Published: March 2011

AbstractPhosphorus segregation at grain boundaries in thin film polycrystalline silicon has been investigated by nuclear magnetic resonance spectroscopy. Amorphous silicon thin frims were deposited by plasma enhanced chemical vapor deposition with 1% phosphine in silane. The films were subsequently annealed at 700°C and 800°C to produce a fine grained polycrystalline material. All of the phosphorus atoms were found to be four-fold coordinated at the grain boundary. The P atoms were found to have three different environments in the grain boundary region. These results will be discussed in relationship to the carrier trapping and dopant segregation models.
A Novel Silicided Shallow Junction Technology for Cmos VLSI
Authors: Kwong D.L. , Ku Y.H. , Lee S.K. , Alvi N.S. , Chu P. , Zhou Y. , White J.M. 
Published: March 2011

AbstractA novel technique for the fabrication of shallow, silicided p+-n junctions with excellent electrical characteristics has been developed. The technique utilizes the ion implantation of dopants into silicide layers formed by ion-beam mixing with Si ions and low temperature annealing, and the subsequent drive-in of implanted dopants into the Si substrates to form shallow junctions. This technique can be easily applied to the fabrication of MOSFETs in a self-aligned fashion, and can have a significant impact on CMOS VLSI technology.
Shallow Silicided Junctions for VLSI Cmos Transistors by Furnace and Rapid Thermal Processing
Authors: Butler A.L. , Foster D.J. , Pickering A.J. 
Published: March 2011

AbstractAs a result of device scaling very shallow low resistance diffusions are required for VLSI CMOS fabrication. This paper describes a technique for their formation using silicon implantation for preamorphisation, counterdoping arsenic implantation and overall boron fluoride implantation for the sources and drains of the n- and p-channel transistors. Platinum silicidation has been used to reduce diffusion and polysilicon sheet resistances to 8Q/square. Activation of the shallow diffusions has been achieved either by furnace annealing (FA) or rapid thermal annealing (RTA) in the range 900°C to 1100 °C. Materials results are discussed including TTEM, SIMS and SR profiling. The suitability of the technique for VLSI CMOS applications is demonstrated by the fabrication of sub-micron transistors. With larger wafer diameters (>5') the FA conditions considered are not practicable owing to ramped diffusion effects which lead to deeper junctions. Hence RTA is necessary: optimum conditions found were 1100 °C for 10 seconds when device performance equivalent to or better than FA can be achieved.
Applications of High-Pressure Technology to Ulsi Fabrication
Authors: Tay S.P. , Ellul J.P. , King M.I.H. 
Published: March 2011

AbstractA discourse is presented on the diverse manners and extent to which high-pressure reactors are being utilized in the semiconductor industry and their potential employment in research and development for ULSI fabrication. Various versions of high-pressure reactors are described. The major advantages of high-pressure techniques stem mainly from the ability to use lower processing temperatures which leads to reduced impurity diffusion, less wafer warpaqe, and fewer substrate defects. The exploitation of these benefits in LOCOS and FIPOS technologies for silicon IC device isolation is demonstrated. High-pressure steam has also been used to induce low-temperature reflow of PSG and BPSG before metallization. The applications and limitations of this technology are critically reviewed. Other application areas of high-pressure technigues being investigated extensively by R&D workers are discussed. These include the formation of reliable thin dielectrics in high-pressure ambients of oxygen, steam, nitrogen and ammonia, as well as the improvement of device reliability by using high pressure forming gas (H2/N2) in post-metallization annealing of radiation damage. Enhanced capabilities required for a conventional high-pressure reactor to achieve these applications are discussed. The review is complemented with data which reveal a rapidly growing utilization of high-pressure reactors for production as well as a steady growth in the number of potential applications for high-pressure techniques.
Growth and Characterization of Epitaxial Insulating CaF2ON Si
Authors: Phillips Julia M. 
Published: March 2011

AbstractThe growth of epitaxial insulators on semiconductors in general and on Si in particular is an area of research which has developed quickly over the last five years. Most of thecurrent interest is in films of materials which can be grown by molecular beam epitaxy. A significant fraction of all of the work in this area has concerned the CaF2/Si system. This review will cover that body of work.
Precipitation of PZT and PLZT Powders Using a Continuous Reactor
Authors: Schwartz R. W. , Eichorst D. J. , Payne D. A. 
Published: March 2011

ABSTRACTPZT and PLZT powders were prepared from nitrate and chloride precursors in a continuous constant volume precipitator. After precipitation, the powders were dried by a variety of methods, including: spray-drying, freeze-drying (in liquid nitrogen), and centrifugal freeze-drying. Spraydried powders were found to have a spherical morphology, and to be solid. The particle size was in the micron range. Powders dried by nitrogen freezedrying were characterized by an open morphology of agglomerated platelets. For centrifugally freeze-dried powders, particle size analyses were found to fit a population balance model, giving crystallite, cluster, and agglomerate population densities and growth rates.
Kinetic Investigations of Alkoxysilane Sol-Gel Processing
Authors: Hardman-Rhyne K. A. , Coyle T. D. , Lewis E. P. , Spooner S. 
Published: March 2011

ABSTRACTEffective control of sol-gel glass processing requires a detailed understanding of the kinetic and mechanistic aspects of the process. We have investigated structural evolution at the molecular level in the tetramethoxysilane (TMOS) hydrolysis reaction by various spectroscopic techniques. Development of structure at the macromolecular level and evolution of particle/network dimensionality have been studied by small-angle x-ray scattering (SAXS) in both hydrogenated and fully deuterated reactions for silica macromolecular structural development.
Movement of a Drying Front in a Porous Material
Authors: Shaw T. M. 
Published: March 2011

ABSTRACTA technique is described for directly observing the movement of a drying front through a thin layer of porous material. The observations show that the front moves in abrupt steps and develops an irregular morphology as it advances. Comparison of the experimental images with computer simulations indicates that several features of the drying front can be accounted for by a model based on invasion percolation.