bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vertical Bipolar Transistors and a Merged 3–D Vertical Bipolar—Mos Device in Recrystallized Polysilicon
Authors: Sturm J.C. , Gibbons J.F. 
Published: March 2011

ABSTRACTThe minority carrier properties of shaped—beam laser-recrystallized polysilicon films have been studied, leading to the successful fabrication of vertical bipolar transistors in these films and to the demonstration of a novel three—dimensional mergedvertical bipolar—MOS device. Experiments with lateral transistors established a minority carrier diffusion length of 4 μm in p—type recrystallized films. Vertical bipolar npn transistors with a base—width of 0.2 μm were fabricated in 0.75–μm—thick films using a polysilicon emitter technology. The strong dependence of the gain of the transistors on hydrogen annealing steps is described. With an Ar:H plasma anneal to decrease base—emitter space—charge region recombination, a common—emitter current gain of 100 was possible. The bipolar transistor technology was then used to develop a 3—D fourterminal merged verticalbipolar—MOS device in a recrystallized film. It consists of the three terminals of a bipolar transistor plus a fourth underlying terminal which serves to switch the collector current on or off. A simple model for the device is presented.
Latchup Free Lateral Cmos on Laser Recrystallized Silicon
Authors: Sritharan S. , Solanki R. , Collins G. J. , Fukumoto J. , Szluk N. , Ellsworth D. 
Published: March 2011

ABSTRACTLatchup free CMOS devices have been fabricated by forming PMOS transistors in a 0.5μm thick laser recrystallized silicon layer. This recrystallized layer is isolated fram the bulk wafer by a lμm thick oxide layer. The NMOS transistors were fabricated both in the bulk wafer in the region which was used as the recrystallization seeds, as well as in the recrystallized silicon layer itself. Ring oscillators fabricated with 3μm channel length using a bi-layer lateral CMOS structure show a naninal delay of 1.7ns/stage. The MOS devices fabricated in the recrystallized silicon show low subthreshold leakage current, and surface electron and hole mobilities of 580cm2/V.s and 210cm2/V.s respectively.
Leakage Currents in P-Channel Accumulation Mode Tft's
Authors: Khan B.A. , Marshall T. , Arnold E. , Pandya R. 
Published: March 2011

ABSTRACTWe have fabricated accumulation mode MOSFETS in poly-silicon thin films and studied the effect of passivation of the leakage currents in these devices. We have used C-V measurements ot determine the effective doping concentration and depletion layer widths in the passivated and unpassivated devices. We find that passivation reduces the effective doping concentration and therefore increases the depletion layer width. Although this change in effective doping concentration is small (less thean a factor of 2), the increase in depletion layer width is sufficient to pinch off the passivated device but not the unpassivated one. This leads to the dramatic reduction in leakage currents after passivation.
On The Rapid Thermal Sintering Of Thin Amorphous Si-Metal-Si Structures
Authors: Natan Menachem 
Published: March 2011

ABSTRACTThe development of rapid thermal annealing (RTA) or sintering (RTS) techniques for processing of Si and compound semiconductor metallizations also opens a new avenue for investigations of the initial stages of high-temperature, solid state reactions in thin amorphous multilayers. Of particular interest in this regard are the nucleation and early growth of silicides. In this study we suggest a method to prepare large numbers of specimens for TEM, using deposition of Si/metal/Si tri layers on electron microscope grids and annealing the grids in an RTA system. The method enables quick determination of first silicide phases, nuclei shape and density, relative nucleation and growth rates and, for some systems, the diffusing species. Seven widely used metals are investigated: Co, Cr, Nb, Ni, Mo, Ti, and Ta. The first silicide phases determined from electron diffraction patterns are listed and compared to first phases reported in longer furnace annealings. TEM cross sections of reacted Si/Ta/Si and Si/Nb/Si show two different growth morphologies, which are discussed in terms of main diffusing species in a proposed model.
Sequence Of Phase Formation In Ni/Ai Contrasted With Ni/Si
Authors: Colgan E. G. , Mayer J. W. 
Published: March 2011

ABSTRACTWe have investigated the interactions of Al/Ni, NiAl3/Ni, and Ni2Al3/Ni thin films between 350 and 500°C. Sequential layer deposition and coevaporation were used to prepare the films which were then vacuum annealed and analyzed by Rutherford backseat tering and X-ray diffraction. Initially, NiAl3 is formed, followed by the more Ni-rich phases. All four intermetallic phases were formed.
Alumina-Ti Interface Reactions Studied By AES And UPS
Authors: Lefakis H. , Liehr M. , Rubloff G. W. , Ho P. S. 
Published: March 2011

ABSTRACTThe interaction of Ti with A12O3 under UHV conditions has been studied by AES and UPS. Ti was deposited by iterated and successively thicker evaporations (up to a total thickness of 91 Å) under UHV conditions onto the alumina substrate at room temperature. The oxide substrate was grown on Al/Si(111) in an adjacent VHV preparation chamber. The last deposition was followed by in situ annealing. It was found that, contrary to indications of thermodynamic considerations using bulk equilibrium data, Ti interacts strongly with alumina at room temperature, dissociating it to metallic Al and forming TiO2 at the interface. This reaction is limited, resulting in an interface width of ∼10 Å and allowing subsequent evaporations to homogeneously cover the products. Annealing to 500°C does not produce any evidence of outdiffusion or extensive interface reactions, implying that the interface oxide is stable and an effective barrier to Al (and/or Ti) diffusion up to this temperature.
Reaction Kinetics, Stress And Microstructure In Titanium-Copper-Titanium Thin Films
Authors: Hu C. -K. , Gupta D. , Wetzel J. T. , Ho P. S. 
Published: March 2011

ABSTRACTInterdiffusion, reactions and microstructure in Ti-Cu-Ti trilayer thin films deposited on silicon wafers have been investigated by Rutherford backscattering, and cross-sectional TEM techniques in the temperature range of 350 to 500 °C. The formation of intcrmetallic compounds was found to be symmetric at both interfaces in Ti-Cu-Ti film package. TiCu compound formed first at low temperature and was followed by TiCu3 at higher temperatures. The stress in Ti-Cu film has also been measured in-situ as functions of both temperature and annealing time by thin fused quartz bending-cantilever beam technique. The stress in metallic Ti-Cu film couple on fused quartz was tensile. The stress increased as both annealing time and temperature increased and followed a parabolic relationship with time due to the growth of the intermetallic compound TiCu3 It was possible to calculate stress in the TiCu3 layer from the changes of stress in the bilayer thin film. The stress in TiCu3 was computed to be at about 3 times larger than the stress in the unreacted Ti-Cu thin film couple.
Formation of New Interfacial Phases in Bimetallic Thin Film Couples Studied by in Situ Annealing X-ray Diffraction
Authors: Vandenberg J. M. 
Published: March 2011

ABSTRACTInterfacial reactions in bimetallic thin films have been studied by in-situ glancing angle X-ray diffraction which enables us to monitor all stages of the interface reaction in the temperature range 35 °-950° C Results are presented on new phase formation in evaporated Ag-Al and Cu-Al thin film couples, sputtered bimetallic Nb-Sn and Nb-Pb films and magnetic alloy films. New phases as well as phase transitions which are not known to exist in the bulk phase diagrams, were observed. These results provided evidence that phases other than those predicted by the first nucleation rule, grow during the initial metal-metal thin film interface reaction.
Dominant Moving Species in the Formation of Amorphous HfNi By Solid-State Reaction
Authors: Cheng Y.-T. , Nicolet M.-A. , Johnson W. L. 
Published: March 2011

ABSTRACTThe displacements of Mo, Zr and Pd markers have been monitored by backscattering of MeV He+ to study the growth of the amorphous HfNi phase by solid-state reaction. We find that the Ni is the dominant moving species in this reaction.
Homogeneous Al-Ti and Al-Ti-Si Thin Alloy Films
Authors: Dirks Albertus G. , Tien Tien , Towner Janet M. 
Published: March 2011

ABSTRACTThe microstructure and properties of thin films depends strongly upon the alloy composition. A study was made of the metallurgical aspects of homogeneous Al alloy films, particularly the binary Al-Ti and the ternary Al-Ti-Si systems. Electrical resistivity, grain size morphology, second phase formation and electromigration have been studied as a function of the alloy composition and its heat treatment.
Ion-Beam Induced Silicide Formation: Markers and Moving Species
Authors: Hung L. S. , Mayer J. W. 
Published: March 2011

ABSTRACTThe moving species in near-noble metal suicide formation was investigated using embedded markers and Rutherford backscattering. With thermal annealing of Ni-silicides, Ni is the dominant diffusing species while in ion-induced reactions both Ni and Si diffuse across the suicide. This difference in behavior is not a result of the formation of amorphous Si during ion irradiation nor is it caused by release of Si. We propose that the diffusion of Si is associated with the formation of defects in the suicide layer generated within the collision cascade.
Formation of GaAs Ohmic Contacts by Using Ion Beam Mixing
Authors: Furukawa S. , Asano T. , Fukada T. , Ishiwara H. , Tsutsui K. 
Published: March 2011

ABSTRACTIon beam mixing effects on metals and highly doped semiconductors on GaAs for formation of ohmic contacts have been studied. In this study, we have principally selected Pt as metal and Ge as semiconductors electrodes for GaAs. In Pt/GaAs system, we observed alloying phenomena induced by Si+, Ar+, Ge+ ion mixing effects. The amount of GaAs reacted with Pt was found to be proportional to the mass of the incident ions for constant dose. Concernig with the formation of ohmic contacts, only in the case of Si implantation through Pt films, the conversion from Schottky- to ohmic-contact was observed due to ion beam mixing effects. In Ge/GaAs system, we observad the solid state epitaxy for implanted Ge layer by the first annealing at 450°C in the two step annealing, but no activation of the implanted species. For activating implanted species, the second annealing at 800°C was effective. Concerning with the formation of ohmic contacts, we observed that the ohmic I-V characteristics for Ge/GaAs system could be obtainable when the following conditions were satisfied at the same time: 1) high dose implantation of As+ into Ge layer, 2) low dose implantation of Si into Ge/GaAs boundary and 3) relatively short period annealing in the second annealing step. From such study, it is concluded that ion beam mixing in conjunction with rapid annealing would be most promising for forming stable and reproducible ohmic contacts.
Ion Beam Mixing Of Marker Atoms in Mo and Ru and Heat of Mixing
Authors: Kim S.-J. , Paine B. M. , Nicolet M-A. , Averback R. S. 
Published: March 2011

ABSTRACTThe effect of the heat of mixing, ΔHm, on the ion beam mixing of marker systems was studied. The matrices for tne experiment were Mo and Ru, and marker atoms were Ti, Cr, Mn, Ni, Hf, Ta, Pt, and Au. These markers and matrices have heat of mixing ranging from +65 to -227 kJ/mol. Irradiations were done with 300 keV Kr at 77 and 300 K, with room temperature backscattering spectrometry analysis. There was no correlation between the mixing results and heat of mixing, which is consistent with the idea of ion beam mixing of dilute marker system.
Effects of Thin Interposing Layers on The Epitaxial Growth of FeSi'2 on Silicon
Authors: Cheng H. C. , Yew T. R. , Chen L. J. 
Published: March 2011

ABSTRACTThin interposing Ni or Co layers between Fe thin films and Si have been shown to be very effective in inducing the growth and improving the quality of epitaxial FeSi2 on silicon. The formation of a transition layer with graded concentration is conceived to facilitate the epitaxial growth of FeSi2 on silicon. The thin interposing layer scheme may be extended to promote the epitaxial growth of a number of refractory suicides on silicon.
High Spatial-Resolution Analysis of Lateral Suicide Formation
Authors: Barbour J. C. , Batson P. E. , Mayer J. W. 
Published: March 2011

ABSTRACTThin-film Ni-Si lateral-diffusion couples were annealed at 450°C for 12 hours to cause formation of the suicide phases: Ni3Si, Ni5-Si2, Ni2Si, and NiSi. Scanning transmission electron microscopy (STEM) was used to investigate the suicide growth. The mechanism of Ni transport to the growth front was shown to be bulk phase diffusion, as evidenced by a bulk phase concentration gradient of 0.03 atomica Ni/nm in the NiSi phase. The transition from thin film kinetic behavior to bulk couple kinetic behavior was found to be greater than 200 nm. The absence of the Ni3Si2 phase in the lateral-diffusion couple was attributed to a nucleation barrier. An excess amount of Ni in the Ni2Si phase at the Ni2Si-NiSi interface indicates the interdiffusivity is lower in NiSi than in Ni2Si, thereby limiting Ni diffusion out of the Ni2Si phase.
Competing Initial Reactions at Transition-Metal/Silicon Interfaces
Authors: Rubloff G. W. 
Published: March 2011

ABSTRACTThe process of suicide formation by contact reaction at metal/Si interfaces normally involves rather uniform motion of the growth fronts which separate metal, suicide, and Si regions, as has been observed for suicide growth in many transition-metal/Si systems. At lower temperatures, however, the reaction behavior can be complicated significantly by the presence of other material reactions which may compete with interfacial suicide formation. For refractory metals, strong interfacial mixing over considerable depth (∼ 100 Å or more) is observed at temperatures too low for the normal inlerlacial suicide formation process to contribute; the highly nonuniform character of this reaction, as shown by ion scattering and TEM studies, suggests that other material reactions (e.g., grain boundary diffusion) must dominate the interfacial chemistry at low temperature. In a similar way, anomalous and nonuniform reaction behavior during the low temperature deposition of initial transition metal layers on Si apparently involves surface diffusion processes which are faster than inlerlacial suicide formation.
Characterization of CDTE Films, Useful In All Thin-Films Solar Cells. I. CD Vacancies And Photoluminescence Spectra
Authors: Figueroa J. M. , Vazquez-Lopez C. , Sanchez-Sinencio F. , Mendoza-Alvarez J. G. , Zelaya O. 
Published: March 2011

ABSTRACTPolycrystalline CdTe films were grown by a hot-wall-close space vapor transport technique. In-doped CdTe films were grown onto conductive tin-oxide glass substrates. In order to produce Cd-vacancies, the films were photocorroded using the electrochemical arrangement reported by C. Vazquez-Lopez et al [4]. CdTe films were photocorroted during different times of illumination. Photoluminescence spectra of these films showed that the peak at 1.55eV grows with the photocorrosion time. Our results indicate that the 1.55 peak is associated to Cd-vacancies which are produced during the photo-corrosion process.
Interactions Of Evaporated Nickel And Silicon Thin Films
Authors: Zheng L. R. , Hung L. S. , Mayer J. W. 
Published: March 2011

ABSTRACTInteractions of evaporated Ni and Si thin films were investigated by a combination of backseat tering spectrometry and transmission electron microscopy. The presence of amorphous Si has no significant effects on Ni2Si and NiSi formation, but it drastically lowers the formation temperature of NiSi. Experiments with evaporated thin markers established that Ni is the dominant diffusing species in the growth of the three suicides. The stability of NiSi was examined by sequential evaporation of Ni34Si66 and Ni50Si50 thin films both on Si(100) and on evaporated Si substrates. The results showed that NiSi2 grows at the expence of NiSi when the stucture is in contact with evaporated Si, while it dissociates into NiSi and Si when in contact with single crystal Si.
Formation of Silicon Nitride films Newly Developed by the Ion and Vapour Deposition Method
Authors: Sugawara F. , Ajioka T. , Ichikawa F. , Ushio S. 
Published: March 2011

ABSTRACTThe Ion and vapour deposition method (IVD method) has been used for the first time to form silicon nitride films. Silicon nitride formation using IVD method, which consists of a nitrogen ion implantation and a simultaneous electron beam evaporation of silicon, has been confirmed.These silicon nitride films formed by IVD method have been characterized using FTIR, ellipsometry and AES analyses. It has been observed that these IVD silicon nitride films characteristics are sensitive to the nitrogen ion implantation conditions and the silicon evaporation rate.Applications of these IVD films to selective oxidation have exhibited a good resistance to oxidation. It has also permitted the bird's beak to be reduced.
AES and XPS Studies of the Chemical Effects at the Magneto-Optic/Dielectric Interface
Authors: Coulman D. , Anthony T. 
Published: March 2011

ABSTRACTThe chemical stability of magneto-optic structures of sputter-deposited SiO, SiO2, or Si3N4/TbFeCo/SiO, SiO2, or Si3N4 was studied in detail. The degradation of the magnetic properties of the TbFeCo film have been correlated with the oxygen content within the film as determined by Auger and RBS. Auger and XPS depth profiles have revealed that for oxygen containing dielectrics the preferential oxidation of terbium is responsible for the observed differences in coercivity. Reduction of the dielectric at the SiO/TbFeCo interface, along with diffusion of oxygen into the RETM film, have been observed. The Si3N4/TbFeCo structure shows no evidence of either interdiffusion between the layers or oxidation of the TbFeCo film. From our investigation we conclude that Si3N4 is a superior dielectric for quadri layer structures in magneto-optic media.
Modified Oxide Properties from Dopant Effects at the Si-SiO2 Interface
Authors: Jackson Michael A. , Salvati Lawrence , Chin Roland L. , Anderson Wayne A. 
Published: March 2011

ABSTRACTBoth thin, 60→140Å thick, and native oxides on As and P doped Si were studied via null ellipsometry and angle resolved ESCA. Results showed higher oxide growth rates to occur for higher surface concentrations of a given dopant. For similar surface concentrations, P-doped samples oxidized faster than As-doped, in both cases. Exact oxidation rates were not determined as results indicate that stoichiometric variations and oxidation of carbon contamination influence thickness determination of these oxides.
MPI/MS Studies of Thin Film Deposition Processes: Methyl Production from Trimethylgallium Decomposition and the Effect of Added Hydrazine
Authors: Squire D. W. , Dulcey C. S. , Lin M. C. 
Published: March 2011

ABSTRACTThe low pressure pyrolysis of alkylmetals on resistively heated substrates was studied using multiphoton and electron ionization mass analysis. The activation energy for the production of gas phase methyl radicals from the decomposition of trimethylgallium under single collision conditions was found to be 26 ± 3 kcal/mol, which is to be compared to 13 ± 2 kcal/mol previously observed for trimethylaluminum. No evidence could be found for any surface radical reactions leading to the production of CH4 or C2H6. A proposed deposition mechanism accounting for these observations was tested by pyrolyzing trimethylgallium in the presence of hydrazine. No change in methyl signal was observed, supporting the theory that radical reactions do not occur on the surface under the conditions employed.
Effect of Argon and Hydrogen on Deposition of Silicon from Tetrachlorosilane in Cold Plasmas
Authors: Manory R. R. , Avni R. , Grill A. 
Published: March 2011

ABSTRACTThe roles of Ar and H2 on the decomposition of SiCl4 1n cold plasma were Investigated by Langmulr probes and mass spectrometry. Decomposition of the reactant by Ar only has been found to be very slow. In presence of H2 in the plasma SiCl4 is decomposed by fast radical-molecule reactions which are further enhanced by Ar due to additional 1on-molecule reactions in which more H radicals are produced. A model for the plasma-surface Interactions during deposition of pC-S1 1n the Ar + H2 + SiCl4 system is presented.
Formation of Silicides by Rapid Thermal Annealing Over Polycrystalline Silicon
Authors: Narayan J. , Stephenson T. A. , Brat T. , Fathy D. , Pennycook S. J. 
Published: March 2011

ABSTRACTThe formation of titanium suicide over polycrystalline silicon has been investigated after rapid thermal annealing treatment in nitrogen and argon ambients. After rapid thermal annealing 300 Å thick titanium overlayer at 900°C for 10 seconds, the sheet resistance of about 3 Ω/□ was achieved, which decreased to 2 Ω/□ after 1100°C / 10s treatment. The TiSi2 Phase was found to be stable after RTA treatments up to 1100°C /10s with no or negligible migration of titanium along the grain boundaries in polycrystalline silicon. In the nitrogen ambient, an external layer (titanium rich, mixture of titanium oxide and nitride) was observed to form after the RTA treatment, but the surface was found clean in the argon ambient.
Mechanical Properties of Metallic Films on Sapphire
Authors: List F. A. , Mckee R. A. 
Published: March 2011

ABSTRACTA knowledge of interfacial mechanical properties is of considerable importance to the areas of oxidation, corrosion, metallization, and composite materials. We have developed an experimental apparatus capable of simultaneous measurements of elastic and anelastic properties of materials in controlled atmospheres (10-6 to 104 Pa) from 25 to 1000°C. The apparatus employs the technique of dynamic reasonance in which a material's mechanical resonance spectrum can be determined over a range 102 to 105 Hz with resolution ±0.001 Hz. This resolution has enabled us to determine the mechanical properties of films as thin as approximately 10 nm.We shall present resonance results for thin films (∼100 nm) of nickel and gold on sapphire substrates. These results suggest that nickel films on sapphire are adherent, i.e., cyclic strain is continuous at the film-substrate interface, over a range of temperature about the film growth temperature; whereas gold films show nonadherent behavior at all temperatures studied.
Electromigration Resistance of Multilayer Aluminum/Titanium Interconnects
Authors: Finetti M. , Ronkainen H. , Blomberg M. , Suni I. 
Published: March 2011

ABSTRACTWe have investigated the electromigration resistance of Al-Si/Ti multilayer interconnects. For comparison Al-Si and Al-Si/Ti/Al-Si films were also prepared. The linewidths ranged between 1.6 and 5, um. A temperature-ramp resistance analysis was applied at direct wafer level, to detect electrically transport of material and derive the electromigration kinetic parameters in test vehicles with different geometries.
Low Temperature Oxidation and Spalling of Electrodeposited and Vapour-Deposited Copper
Authors: Fisher Robert M. , Martin Bret , Cannon Rowland M. 
Published: March 2011

ABSTRACTThermal cycling of silicon solar cells heated with incandescent light or using an in-situ heating stage on an optical microscope caused unexpectedly rapid oxidation of the electrodeposited copper current collecting grid. Unusually fine buckling and spal ling of the oxide film also occurred at temp. as low as 180°C. These effects appear to stem from the very fine columnar grains and high defect content of the copper ribbons and some Cl residue from the electrolyte. With vapour-deposited Cu, similar relatively rapid oxidation and spalling were also observed. Origins of the high oxidation rates, the large compressive stresses within the oxide and the low-temperature spalling are discussed.