Sub-monolayer native oxide on Si is quantitatively characterized by conventional XPS, us-ing an Ols binding energy as a reference in spectrum decomposition of Si2p. This gives the average thicknesses of Si dioxide and Si suboxide in the sub-monolayer region. Using mis tech-nique, we investigate various native oxidation processes. We have found that oxygen dissolved in the HF solution influences native oxidation speed afterward. Furthermore As implantation at high concentrations (2 × 1015 cm-2) in Si dramatically changes the oxidation process: the layer-by-layer feature clearly observed in undoped samples is entirely obscured in implanted samples.

Characterization of the degradation processes of single mode buried heterostructure quantum well laser diodes using traditional electrooptical parameters as well as the parameters of internal second harmonic radiation (SHR) were performed. In order to observe the stages of degradation process, especially in the vicinity of catastrophic optical damage of the laser mirror, single current pulses were superimposed on DC driving current. It was shown that the intensity of SHR is indicative of the laser diode mirror working regime: the bigger SHR intensity corresponds to the bigger optical power density on the mirror and the higher risk of mirror catastrophic optical damage.

Recent experiments using scanning tunneling microscopy (STM) show evidence for the formation of surface alloys of metals with a broad miscibility gap. Such is the case for Au deposited on Ni(110), where STM images indicate that at low coverage Au atoms squeeze Ni atoms out of the surface layer forming a surface alloy while the Ni atoms form islands on the surface. We present results of a theoretical modelling of this phenomenon using the BFS method for alloys. We find evidence which strongly support the conclusions drawn from experiment. Ni island formation and alternative short range order patterns are discussed, as well as the transition from a surface alloy phase at low coverages to phase separation at higher coverages.

The sheet resistance of TiSi2 films formed on patterned sub-half micron n+ polysilicon lines has been observed to be higher than the sheet resistance of unpatterned blanket TiSi2 films. We have investigated this phenomenon, and determined that the TiSi2 thickness is not a function of linewidth, and that the resistivity increase in narrow n+ lines is caused primarily by incomplete phase transformation to the low-resistivity C54 phase. We have determined a physical model for the kinetics of this phase transformation, based on an Arrhenius-type atomic re-arrangement process, and we have determined an activation energy (Ea) of phase transformation for different linewidths. We have observed that this Ea increases non-linearly as a function of decreasing linewidth, contrary to conventional belief. We have hypothesized that this increase is due to increasing dominance of edge-related phenomena such as contaminant segregation, strain etc. Finally, we have demonstrated that by supplying this Ea through a high temperature (825°C) anneal, even applied for a short time (15 s), low sheet resistances (<4 Ω/ü) can be obtained down to 0.35 μ m lines.

We have studied the influence of interface roughness scattering on the mobility of two-dimensional electron gas(2DEG) in GaAs-AlGaAs modulation-doped heterostructures(MDH) both experimentally and theoretically. When the background ionized impurity concentration in the GaAs layer is smaller than 2.5×1015cm-3, our investigation shows that interface roughness scattering is the dominant scattering mechanism in the high 2DEG density(Nş ≥5× 1011cm2) GaAs-AlGaAs MDH. We also demonstrate that interface roughness scattering is about an order of magnitude stronger than alloy disorder scattering in GaAs-AlGaAs MDH if the AlGaAs/GaAs interface fluctuation is only one monolayer of GaAs.

The pump-producing industry uses solid SiC combinations for tribological components. Thanks to their outstanding corrosion resistance, hardness, thermal stability and other qualities, such pairings have gained widespread acceptance, particularly for mating and sliding surfaces. For structural reasons, the brittleness and low tenacity of solid SiC limit its range of applications. The ideal solution, of course, would be to find a coating with identical desirable properties.

Zirconia and zirconia-yttria coating films and powders obtained by the sol-gel route using a zirconium alkoxide as starting material and acid and neutral catalytic were investigated by the Perturbed Angular Correlations method (PAC), XRD, DTA and TGA. The hyperfine interaction was measured either during heat treatements or after annealing the samples at increasing temperatures up to 1200°C. All samples have presented a high fraction of crystalline phases at low temperatures. The yttria doped cubic zirconia has not shown the phase transition to the monoclinic phase. Pure zirconia powders produced in neutral hydrolysis and zirconia coatings produced in acid catalysis stabilized the tetragonal phase in a high fraction and up to high temperatures.

We report new results on nano-scaled oxide films deposited by an RF aerosol mist plasma technique: including indium tin oxide transparent conductive films; yttria stabilized zirconia, nickel iron oxide/YSZ cermet, and lanthanum strontium manganite for fuel cell applications; Bi2Sr2Ca2Cu3Ox superconductor films; gadolinium iron oxide for magnetic heat pumps; silicon oxide for protective coatings, etc. Since this deposition process occurs in an atmospheric environment, it has potential for large scale production. The maximum deposition rate is approximately 1 micrometer per minute per centimeter squared. Substrate temperatures were between 300°C and 900°C. Crystal sizes are analyzed by XRD (Shadow Programs). Some films were also characterized by resistance, optical(IR-UV-Vis transmission/reflection and FTIR) and Mössbauer measurements. Film morphology was found to be strongly dependent on deposition parameters. Controlling the deposition rate by altering solution concentration and mist feed rates, as well as altering plasma torch settings and substrate temperature allowed the formation of different film morphologies. Film density, thickness, and crystallite size could be controlled to obtain films of differing characteristics. This is advantageous to fuel cell depositions where a dense electrolyte as well as porous electrodes (anode and cathode) are required.

The deposition of InAs on GaAs results, above a 1.75 monolayer coverage, in the formation of dots on a residual 2D wetting layer. Atomic force microscopy (AFM) measurements show that these dots are in the quantum size range (height 3 nm, half-base 12 nm). Transmission electron microcopy (AFM) observations show that they are coherently strained and the corresponding strain contrast is simulated using the dynamical electron diffraction contrast theory. The dot strain fields used for the TEM contrast simulations are either deduced from continuous elastic models or determined by valence force field (VFF) atomistic calculations. That experimental TEM images and simulated images should match shows that the methods of determination of the dot strain fields are valid.

Re-emissions from surfaces receiving a ballistically transported molecular flux have, in the most general case, a spatial distribution with a combination of specular and diffuse components. The addition of specular transmission in the EVOLVE model allows combined specular-diffuse re-emission to be explicitly modeled. Previous modeling of the step-coverage of sputtered titanium nitride (TiN) films in contact structures produced good predictions with a sub-unity sticking coefficient, 0.6 in value, using a strictly diffuse formulation for material re-emission. New data of collimated sputtered TiN with contact aspect ratios exceeding 4.0 was modeled using the EVOLVE specular-diffuse formulation. The result was more accurate model predictions of experimental data and replacement of the ad hoc empirical parameter adjustment in previous modeling with a more detailed physical description.

This paper presents the results of very low temperature micro-meter-order polycrystalline silicon growth on SiO2 and glass substrates. The silicon films were deposited with high growth rate using hydrogen dilution method by the electron cyclotron resonance chemical vapor deposition at 250°C and without any thermal annealing. The polycrystallinity of silicon films was identified by plan-view transmission electron microscopy (TEM). The maximum grain size distinctly exceeds 1 μm Raman spectroscopy was used to identify the volume ratio of crystallinity in poly-Si films. Atomic force microscopy (AFM) and X-ray spectroscopy were used to study the surface morphology and film crystallinity, respectively. We believe that our work could possibly change the future course of the hydrogenated silicon research.

In this work we present some results of a systematical study of structural and optoelectronic properties of Zn O: In thin films obtained by spray pyrolysis when the acidity and the solvent used in starting solution were varied. Structure of our samples was derived from X ray diffraction and conventional electron microscopy observations.

Capillary instability poses a serious concern for applicability of thin layers in next generation of microelectronics devices. Two completely independent models, Mullins' Grain Boundary Grooving model and the Geometrical Agglomeration model have been used to explain capillary instabilities in CoSi2 layer formed on polycrystalline and single crystal substrates, respectively. Inadequacies of these separate models have been highlighted in our experimental work using cross-sectional transmission electron microscopy. A new empirical model, which incorporates both of these models, will be presented which shows the dependence of groove depth on annealing duration, diffusion coefficient, annealing temperature and grain diameter to film thickness ratio, D. The new model not only explains the various peculiarities of silicide grooving on both single and polycrystalline substrates, it also predicts the severe agglomeration of nanoscale layers experimentally observed during silicide formation by Co/Si reaction at 700 °C, 10 sec rapid thermal anneal. Also, experimental verification of agglomeration suppression schemes which are based on the above empirical model will be presented.

Amorphous ZrCo-alloy films, prepared by electron beam deposition in ultra high vacuum (UHV), are investigated in situ with scanning tunneling microscopy (STM) in constant current mode. The topographs, statistically analysed by height-height-correlation functions, show a surface roughness on two different length scales. The surface structures on a larger scale (7.0 to 12.0nm in diameter), which vary with substrate temperature, film composition and film thickness, are discussed in relation to surface tension and diffusion kinetics during film growth. The structures on a smaller scale (0.4 to 0.7nm in diameter) have to be discussed with respect to the limits of atomic resolution.

Bismuth titanate (Bi4Ti3O12) thin films were produced from acetate precursors by spin coating deposition followed by crystallization using rapid thermal processing (RTP)‥ Crystallographic orientation was characterized by x-ray diffraction, and indicated that it varied with the number of coating layers for the films deposited on single crystal silicon wafers. Cross sectional samples were prepared and studied by Transmission Electron Microscopy (TEM). The results showed that grains randomly nucleated at the interface where a thin amorphous silica layer was naturally formed. Grains nucleated in the [020] direction or near this direction showed a faster growth rate than that in the other directions, and eventually dominant in determining the grain orientation of the film. Preferential orientation in the [020] direction observed by TEM is identical to the XRD results for the multilayer thin films. The thickness and grain size of thin film were also investigated.

Reflection high energy electron diffraction (RHEED) and x-ray diffraction (XRD) studies on Ag and Au films grown on hydrogen terminated Si(111) substrates at room temperature indicate a <111> oriented growth. Atomic force microscopy (AFM) data reveal a smooth surface morphology for both Ag and Au films after annealing at 275°C and 175°C for 1 hour, as compared to films without annealing. High resolution transmission electron microscopy (HREM) was employed to examine the annealed samples. HREM studies show a highly uniform film with abrupt interface for Ag/Si(111). On the other hand, Au/Si(111) shows several twin formations both at the interface and in the bulk of the film.

Homopolymerizations of multifunctional monomers produce densely crosslinked polymer networks with structures that are often complex and difficult to characterize. The complexity in the structure arises primarily from the heterogeneous nature of the polymerization such as the formation of microgels. This work presents progress towards developing a better understanding of the highly crosslinked polymer structure through combined experimental and modeling techniques. Electron spin resonance (ESR) spectroscopy was used to examine the concentration and local environment of the radicals, i.e., the fraction of radicals that were trapped and terminate on a long time scale as compared to those which are more mobile and terminate on a shorter time scale. A kinetic gelation simulation was developed to verify the ESR results and provide further information regarding the structural evolution of the network and its heterogeneities.

In this paper, we present directly interpretable atomic resolution images of dislocation structures at interfaces in CdTe/GaAs(001) systems. This is achieved using the technique of Z-contrast imaging in a 300kV scanning transmission electron microscope in conjunction with maximum entropy image analysis. In addition to being used to further the understanding of the relationship between growth conditions and exhibited properties, the data presented provides direct information on the atomic arrangements at dislocation cores.

Metallization lines in advanced integrated circuits are often fabricated from sputter-deposited Ti/Al layers. It is well known that the Ti/Al react above ∼350°C to form T1AI3 with a rate that is dependent on anneal temperature and the alloying content of Cu and Si in the Al. In the present work, the thickness of TiAl3 formed during annealing at 430°C has been determined from the measurement of the sheet resistance of Ti/Al-.5%Cu and Ti/Al-.5%Cu-l%Si bilayers. Analyses of the reacted structures were performed by cross-section transmission electron microscopy and Auger depth profiling. We find that the Si exhibits a greater retardation effect on the Ti/Al reaction than does Cu, as shown previously. Kinetic analysis for the Ti/AlCuSi reaction shows that the TiAl3 formation rate is a function of the Ti/AlCuSi thickness ratio. We propose that this effect is due to several mechanisms which involve diffusion and incorporation of Si into the growing TiAl3layer.

The effects of rapid thermal annealing (RTA) on the electrical properties and the strain relaxation of the heavily boron doped silicon layers grown by molecular beam epitaxy have been studied by Hall effect measurements and double crystal x-ray diffraction. After the RTA treatment at temperatures above 1000°C, the increases of both carrier concentration and Hall mobility as well as the improvement of crystalline quality of epitaxial layers are acheived. It is verified that the lattice mismatch between the epitaxial layer and the Si substrate is proportional to the concentration of the substitutional boron rather than the total boron concentration. The lattice contraction coefficient ² is determined to be 5.3 (in units 10-24cm3) in the carrier concentration range of 0.75∼ 3×1020cnr-3.