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Research was conducted to examine the growth behavior of epitaxial CoSi2 layers o Si(100) substrate developed by rapid thermal annealing at 800 degrees C in N2 ambient without capping layers from an amorphous cobalt-carbon film. The electrical properties of the p+n junction diode and the thermal stabilities of CoSi2 film and diodes were also investigated for their practical application to deep submicron devices. Results suggest that epitaxial (100) CoSi2 is thermally stable at temperatures even above 1000 degrees C and has potential application to the salicide process in subhalf micron devices.

Research was conducted to examine in detail the cathodoluminescence, microstructure and morphology of tensile-strained Al(sub x)Ga(sub 1-x)N thin epitaxial films. Cathodoluminescence was observed from the donor bound exciton as well as a number of donor-to-acceptor pair transitions. The extent of relaxation of Al(sub x)Ga(sub 1-x)N epitaxial films was determined by a combination of X-ray results and x-ray photoelectron spectroscopiic data.

Research was conducted to examine experimentally the deposition rate, elemental composition and the spatial distribution of the deposition rate and of the composition in the deposit during room temperature laser ablation of multicomponent targets of PbZr0.65Ti0.35O3, Bi2Sr2CuO6 and CuInSe2. A number of discrepancies were revealed by a comparison of the obtained experimental data with previous results. Findings suggest that the discrepancies are associated with the assumption in the modeling of unit sticking probability of the species.

Research was conducted to investigate the superposition of growth selectivity on patterned GaAs (311)A substrates at the intersection of fast and slow growing mesa sidewalls by molecular beam epitaxy. Surface morphologies can be explained by the straightforward addition of growth selectivity in terms of the amount and the direction of migrating adatoms. Results provide the basis for the formation of novel lateral semiconductor nanostructures on patterned GAAs (311)A substrates.

Research was conducted to examine the phase sequence of the rapid thermal processing induced reaction at T = 650 degrees C using combined high resolution transmission electron microscopy and image simulations. It was observed that pre-amorphization of poly-Si substrates does not alter the reaction path. Direct evidence is provided showing that the Ti-Si reaction in the Mo doped system follows the template mechanism with MoSi2 and Mo5Si3 based phases acting as template phases for accelerated growth of C-54 TiSi2.

Research was conducted to obtain the orientational constraints for cubic crystals which arise from growth under a general biaxial stress field. The electron diffraction patterns of face-centered-cubic specimens with both negative and positive values of delta are measured by means of a program in MATLAB and exhibited in a manner that is appropriate for direct comparison with experiment. A comparison of a diffraction pattern from a cross-sectional TiN film and diffraction patterns from a previous experiment was performed.

Atomic force microscopy has been used to analyze the potassium dihydrogen phosphate crystal surface as it emerges from the 'dead zone,' a regime of low supersaturation where growth stops. It has been established that resurrection out of the dead zone is not prompted by elementary steps breaking through the fence of impurities. Instead, it takes place by the motion of macrosteps alone. Impurities are only able to pin individual elementary steps. Therefore, all impurity pinning sites within the macrostep are buried by the rest of the macrostep, apart from those along the uppermost step.

A method for producing single-domained Y123 crystals via top-seeded melt growth using two step undercooling has been developed. The technique resulted in a large reduction in the amount of time needed to grow the Y123 single-domained crystal. The two step undercooling process, whose resulting Y123 crystals were subjected to analyses of both microstructure and texture, also exhibited no degradation in the superconducting characteristics of the fabricated superconductors.

A wide variety of YBa2Cu3O6+x grain boundaries were created using seeding techniques to control the orientation of grains. In addition, a method to produce grain boundaries in the same sample that have the misorientations theta(001) tilt, theta(100) tilt and 90 degrees-theta(100) where the misorientation angle theta is fully controllable was developed, aside from the five existing domain samples with 90 degrees (100) twist and tilt grain boundaries.

The Crystal Peak area of the Pikes Peak batholith, near Lake George in central Colorado, is world-renowned for its crystals of amazonite (the blue-green variety of microcline) and smoky quartz. Such crystals, collected from individual miarolitic pegmatites, have a remarkably small variation in crystal size within each pegmatite, and the shapes of plots of their crystal size distributions (CSDs) are invariably lognormal or close to lognormal in all cases. These observations are explained by a crystal growth mechanism that was governed initially by surface-controlled kinetics, during which crystals tended to grow larger in proportion to their size, thereby establishing lognormal CSDs. Surface-controlled growth was followed by longer periods of supply controlled growth, during which growth rate was predominantly size-independent, consequently preserving the lognormal shapes of the CSDs and the small size variation. The change from surface- to supply controlled growth kinetics may have resulted from an increasing demand for nutrients that exceeded diffusion limitations of the system. The proposed model for crystal growth in this locality appears to be common in the geologic record, and can be used with other information, such as isotopic data, to deduce physico-chemical conditions during crystal formation.

Simulations of crystal growth in hydrous albite-quartz and albite-orthoclase systems were performed with the Jackson, Gilmer, and Temkin formulation of the Ising model. These simulations demonstrate that at 873 K (approximately 100 K undercooling), comb textures are produced when growth and diffusion probabilities are equivalent. If the growth probability is decreased to 0.1 times that of diffusion, discrete alternating zones of albite and quartz are produced; however, increasing the growth probability to 10 times that of diffusion results in an intergrowth of small domains of albite set in a quartz matrix. At near-liquidus temperatures (973 K), textures similar to those at 100 K undercooling are produced although the crystal-melt interfaces of the comb texture are smoother and the absolute value of the diffusion probability exerts a strong control on the texture, unlike results at 873 K. The textures produced in the simulations with a scale of [10.sup.-7] m are similar to experimentally produced textures with scales of [10.sup.-6] to [10.sup.-4]. The fractal dimension of a comb-textured simulation has been measured and shown to be similar to the fractal dimension of a natural pegmatite with a meter-scale texture. This scaling similarity suggests that these simulations may provide insight into the formation of natural pegmatites despite the 5-7 orders of magnitude difference in scale.

A model is developed to analyze the growth of benzophenone crystals in magnetic field intensities of up to 80.0 KOe. The crystals were grown in a solution of benzophenone dissolved in hot n-hexane which was allowed to stand for five hours. Results show that the probability that crystals are oriented increases with increasing field intensity. The orientation also conforms with the Boltzmann distribution for crystals with different magnetic energies.

Slow-scan voltammetric experiments were carried out to demonstrate that the stepwise electrochemical growth of the first and second monolayers of Ag2S on Ag(111) electrodes in aqueous hydrosulfide solutions can be seen as well-defined waves. The two monolayers have similar structures based on x-ray photoelectron spectroscopy and coulometric analysis. However, they have different free energies of formation since oxidative formation occurs at various electrode potentials.

Simulations of the flow field and temperature distribution in a low grade vertical continuous cooling sugar crystallizer were carried out by numerically solving the Navier-Stokes equations in a cylindrical coordinate system. The model results indicate highly nonuniform massecuite cooling, primarily due to the massecuite's large Prandtl number, and significant short-circuiting of flow between inlet and outlet. Modifications to the crystallizer design are proposed and demonstrated to be successful in improving the performance of the vessel.

The large lattice mismatch between 3C-SiC and silicon of approximately 20% is decreased to less than or equal to 0.4% when the commensurability of five 3C-SiC to four Si lattice planes with one misfit dislocation parallel to the film/substrate interface can be used for the pseudomorphic growth. Several nanometer thin pseudomorphic films have been successfully produced. The production of voids in the silicon substrate because of Si evaporation can be strongly suppressed by a newly developed deposition process.

Research was conducted to examine two CoSi2/Si(1-x)Ge(sub x)/Si(100) heterostructures with different Ge content and developed by molecular beam epitaxy. Characterization was done using high resolution electron microscopy. Results indicate that different interface structures exist between the Si(sub 1-x)Ge(sub x) layer and the CoSi2 thin film although the prevailing interfacial configuration is similar to the unreconstructed interface present at the CoSi2/Si(100) interface.

The influence of high dose ion irradiation through amorphous surface layers in single crystalline 6H-SiC at elevated temperatures was analyzed. Quantification for irradiation at 500 degrees Celsius was conduced on material swelling, subsequent densification and surface erosion. Ion beam induced recrystallization was examined in the temperature range from 300-1300 degrees Celsius. The findings indicate that perfect epitaxial regrowth in (0001)-oriented 6H-SiC cannot be achieved by ion irradiation at elevated temperatures.

Research was conducted to examine the catalytic properties of growing small silver particle. The silver clusters were prepared by the reduction of silver ions in the presence of an electron acceptor dye. It was observed that the silver particles were more efficient catalysts than stable coloidal particles. The catalytic characteristic of the particles is attributable to efficient particle-mediated electron transfer from the BH4- ion to the dye and depends on their size and the dye-particle interaction.

A study was conducted to compare the linear and nonlinear optical properties of 2-amino-5-nitropyridinium-dihydrogenarsenate and -dihydrogenphosphate organic-inorganic crystals. The measured nonlinear coefficients of both crystals were found to be high enough for many efficient optical interactions such as tuning optical parametric oscillators. Results also showed that the dispersion in wavelength of the crystals' reflective indices allows phase matching in their complete transparency range from 420 to 1400 nm.

Research was conducted to examine the transition from five-fold symmetric to twinned FCC gold particles by thermally induced growth. The objective is to study the details of any structural rearrangement that may arise during thermal treatment of highly dispersed metal particles in a preceramic inorganic matrix using in situ X-ray diffraction method. Results indicate that accurate X-ray data and simulations using the Debye functions can provide valuable insight into the complex process of crystal growth for nanocrystals.

This paper treats the forced convection, which is produced by the rotation of the crystal about its vertical centerline during the liquid-encapsulated Czochralski or Kyropoulos growth of compound semiconductor crystals, with a uniform vertical magnetic field. The model assumes that the magnetic field strength is sufficiently large that convective heat transfer and all inertial effects except the centripetal acceleration are negligible. With the liquid encapsulant in the radial gap between the outside surface of the crystal and the vertical wall of the crucible, the forced convection is fundamentally different from that with a free surface between the crystal and crucible for the Czochralski growth of silicon crystals. Again unlike the case for silicon growth, the forced convection for the actual nonzero electrical conductivity of an indium-phosphide crystal is virtually identical to that for an electrically insulating crystal. The electromagnetic damping of the forced convection is stronger than that of the buoyant convection. In order to maintain a given balance between the forced and buoyant convections, the angular velocity of the crystal must be increased as the magnetic field strength is increased.

During semiconductor crystal growth with an externally applied magnetic field, thermoelectric currents may drive a melt circulation which affects the properties of the crystal. This paper treats a model problem for a floating zone process with a uniform axial magnetic field, with planar solid-liquid interfaces, with a cylindrical free surface, with a parabolic temperature variation along the crystal-melt interface, and with an isothermal feed rod-melt interface. The ratio of the electrical conductivities of the liquid and solid is a key parameter. The azimuthal velocity is much larger than the radial or axial velocity. There is radially outward flow near the crystal-melt interface which should be beneficial for the mass transport of dopants and species.

A study is conducted on the film growth of fully chemically ordered FePt (001) epitaxial thin films. Results show that these films have high degree of expitaxy and chemical ordering. Highly interconnected magnetic stripe domains with magnetization perpendicular to the film were found in films thicker than 50nm, which lead to characteristic low remanence magnetization curves. Two mechanisms that lead to irregular domain patterns and high remanence and coercivity in the polar hysteresis loops are also determined.

The Bridgman and liquid-encapsulated Czochralski crystal growth processes were simulated using a curvilinear finite volume-based numerical method. New properties of grid generation were developed and added to the original model to make it suitable for global simulation. The model takes into account the convection in both the melt and the gas phases, conduction in all solid components and convection/radiation in the furnace. Results showed that the flow patter and interface shape is strongly dependent on thermal conductivities of the crystal, ampoule and melt materials.

The mechanism of convection in the melt, conduction in the crystal and radiation from the melt free surface and crystal was investigated using a thermal-capillary dynamic numerical model for Czochralski growth of silicon single crystal. It was found that the shapes of the crystal/melt interface, free surface and moving crystal are regulated by the balance of energy and stresses. Results also showed that the diameter of the crystal can remain constant or vary with time based on the approaches used to govern the growth process.

The crystallographic texture selection mechanisms during the ion beam assisted deposition (IBAD) of polycrystalline films are determined using molecular dynamic simulations of IBAD. The simulations involve growing a face centered cubic bicrystal made up of (111) and (110) oriented grains while an ion beam impacted the growing film at normal incidence. It is shown that both ion beam induced atomic sputtering from the surface and ion beam induced damage are reduced when the ion beam is oriented along the channeling directions of the crystals.

A study is conducted on the single crystal growth and ferroelectric properties of A-site filled tungsten bronze-type alpha(Ba(sub 1-x)Sr(sub x))Nb2O6:beta(Na(sub 1-y)Ky)NbO3 (where alpah:beta = 2:1, 9:2, x = 0.75, 0.60 and y = 0.50, 0.40 and 0.25). It is shown that compositions with low ratios of Ba and Na in the 2:1 section plane have high polarizability, low dielectric loss and ferroelectric relaxor characteristics.

A study is conducted on epitaxial Fe3O4/CoO and Fe3O4/Co0.16Fe2.84O4 films grown on MgO via pulsed laser deposition. Results show large exchange bias fields for the Fe3O4/CoO system. The dependence of the exchange bias field on Fe3O4 thickness also follows an 1/d relation indicating a homogenous magnetization reversal process in the soft magnetic layer while a thin interface layer with a helical type, reversible spin rotation is observed.

Two chemical methods were used to synthesize nanocrystalline aluminum. The first method involves the reaction between LiAlH4 and AlCl3 in a trimethylbenzene solvent. This reaction produces crystals with diameters ranging from 110 nm to 210 nm with 84% to 91& purity. The second method involves the decomposition of H3Al(NMe2Et) in a similar solvent as the first reaction. The second procedure yields crystals with more than 99% purity. The growth of these aluminum nanocrystals under pressure is investigated.

Models of crystal growth were defined by comparisons of macroscopic growth kinetics with theoretical predictions. The classic Burton-Cabrera-Frank (BCF) theory has often been observed, but such growth is sometimes inhibited, thought to be due to impurities. Tests on the growth of barite crystals were undertaken using in situ observations and computer simulations of growth units. Strongly anisotropic growth of two-dimensional nuclei was observed, and structure-induced self-inhibition of spiral growth was seen.

Research was conducted to examine reciprocal space maps of PbTe/SnTe superlattices. To change the strain profile in the superlattices from completely pseudomorphic to partially relaxed, the individual layer thickness and number of repetitions were selected. Results demonstrate the importance of detailed structural characterization on the interpretation of electrical properties.

Research was conducted to examine the growth of pinhole-free epitaxial DySi2-x films on atomically clean Si(111) by depositing a 2-micron-thick Dy layer onto Si(111) with a 1.5-nm-thick capping amorphous Si layer at room temperature followed by annealing at 700 degrees C in ultrahigh vacuum. A new mechanism based on experimental findings is proposed. Results indicate that the depth and size of the recessed regions increase with annealing time.

Research was conducted to examine the environment of Er in epitaxial Ca1-xErxF2+x thin films using extended x-rays absorption fine structure and electron spin resonance studies at low temperatures. Film quality was compared with that of films grown by the molecular beam epitaxy method using photoluminescence experiments. Results indicate that the films are more convenient than the bulk materials to use in optical devices.

A major problem in semiconductor device technology is the control of the formation of crystalline imperfections. Surface morphological change from flat to wavy surfaces in nanometer scale during crystal growth has been experimentally shown to make misfit strain relieve. An anisotropic linear stability analysis has been attempted to examine the dependence of surface morphological stability on the directions of surface undulations.

School children growing crystals in the laboratory see that they are not round, although the kinetic molecular theory of matter suggests that they should be spheres. The anomaly can be explained by showing that crystals only grow spherically if the crystallization process is rapid and will adopt other characteristic shapes if they are grown under more usual conditions.

Research was conducted to examine the nature of epitaxy, defects and heterointerfaces in zinc oxide films developed on (0001) sapphire. The objective was to explore the possibility of utilizing it as a buffer layer for growing group III nitrides. Film characterization was performed using Topcom 002 B electron microscope and XRD methods while electrical resistivity calculations were conducted using the four-point probe technique. Results indicate that an interfacial reaction creates a polycrystalline layer at the growth temperatures between 750-800 degrees C.

Research was conducted to examine the bias-enhanced nucleation and the early stages of diamond growth on molybdenum. A prerequisite for the experiment was the in situ deposition of the diamond film which was transferred from the MW-deposition reactor to the PES-analysis chamber without breaking the vacuum. A comparison of the results with results derived from the bias-enhanced nucleation on silicon was performed.

Research was conducted to investigate the properties of Ga(sub x)In(sub 1-x)P-(Al(sub y)Ga(sub 1-y))0.52In0.48P strained quantum-well lasers at compressive strains of greater than 1%. Low-pressure metal organic chemical vapor deposition was used to grow the structures containing single 100-angstroms Ga(sub x)In(sub 1-x)P quantum wells of various compositions. Results demonstrate a strain-induced degradation of the structures.

The magnetic and structural characteristics of Fe(001) grown via molecular beam epitaxy on magnesium oxide substrates were examined at varying temperatures. The islands formed by iron from 80 to 595 K proportionally increased with temperature. For the completed films, the magnetic properties resemble those for systems with biaxial coercivity, with the ratio of the cubic anisotropy constant and magnetization remaining constant. A marked shift in the structure and magnetic properties beyond 595 K was also noted for the system.

Electromagnetic levitation was employed to undercool bulk samples of eutectic Ni 21.4 at% Si alloys. Large undercoolings were realized by containerless processing of the melts. Speeds of crystal growth were determined in relation to undercooling. The growth kinetics during solidification of the eutectic alloys was regulated by atomic diffusion. A peak in the relation of the growth speed on undercooling was noted which is caused by the progressively decreasing diffusion coefficient counteracting the improvement of the driving force of crystallization with increasing undercooling.

A study was conducted to elucidate the long-range atomic ordering and phase separation processes in InGaN alloys grown by molecular beam epitaxy. Results revealed that films produced at substrate temperatures from 700 to 750 degrees C with indium concentration greater than 35% exhibit phase separation. Moreover, films produced at substrate temperatures from 650 up to 675 degrees C showed compositional inhomogeneity when the indium content was higher than 25%.

The surface morphology of ZnSe grown on GaAs(001) via metalorganic vapor phase epitaxy was studied to examine nucleation processes. The results showed that the initial nucleation was a function of the precursor that triggered the ZnSe growth. Differences in the initial nucleation process because of the starting precursors were attributed to the variation of the interface structures.

Epitaxial growth of coronene (C24H12) was investigated on substrates with no dangling bonds, such as hydrogen-terminated Si(111), MoS2, MoTe2 and muscovite by applying reflection high-energy electron diffraction. Findings revealed that the sticking coefficient and the maximum thickness of the epitaxial films are strongly dependent on the substrate materials and on the growth temperature.

The influence of substrate temperature on the growth rate, crystal grain size and SiO2 mask stability in the selective epitaxial growth of silicon carbide deposited from SiH4, C2H4 and HCl on silicon dioxide masked silicon (100) was investigated. Results showed that deposition at atmospheric pressure and a Cl/Si ratio of 50 provided good selectivity. Raising the substrate temperature from 950 to 1000 deg C increased the growth rate and the crystal size and enhanced the film's surface morphology.

Research was conducted to examine the effects of convective solute and impurity transport on the crystal growth kinetics of the model protein lysozyme using high-resolution optical interferometry. To quantify changes in unsteady kinetics with flow velocity, Fourier spectra was employed. Results demonstrate that earlier observations of slow protein crystal growth kinetics are related to step bunch formation in response to nonsteady step generation.

Research was conducted to examine the epitaxial growth of CdTe bilayers electrodeposited onto Au single-crystal surfaces using in situ scanning tunneling microscopy. Alternate reductive underpotential deposition (UPD) of Cd and Te and the electrochemical atomic layer epitaxy method were used to generate the films. Results indicate that the growth of the bilayer is dominated by the requirement to achieve stoichiometry and the initial coverage of the Te UPD layer is of overriding importance during the initial growth phase.

Research was conducted to examine surface aggregation as a necessary condition for interfacially induced crystal nucleation using surface forces apparatus. The chloride salt of the rod-shaped dye bis(dimethylamino)hepatmethine in water was used as a model system. Results demonstrate an indirect correlation between the bulk concentration of the rod-shaped cation and the concentration at an isolated surface.

An in situ investigation of oxygen diffusion in and out of YBa2Cu3O7-delta thin films was conducted using real time ellipsometry. The ellipsometric spectra were obtained for photon energy range from 1.4 to 4.5 eV for varying film thickness. Oxygen out-diffusion was found to be a function of film thickness, while the effect on in-diffusion was negligible. The out-diffusion was also greatly affected by the exposure to H20. The results provided strong evidence that the mechanisms for the two processes were different.

A novel photoconductance approach based on frequency-resolved photoconductance was developed to determine the relationship between the microwave reflection coefficient and the carrier recombination process in silicon. The carrier recombination kinetics was described using four variables, which were then used to study Czochralski silicon wafers that considered Nyquist plots. The traps for annealed wafers disappeared above 100 degrees C, while those for as-grown wafers were active in the temperature range of 20-180 degrees C.

Pd/Ge/Au/Pt/Au ohmic contacts on n-type GaSb grown by molecular beam epitaxy was developed to investigate the strong diffusion into the semiconductor for low temperature stress conditions. The resistivity was found to be very responsive to varying thickness of the different layers and to annealing conditions. Results of the microstructure analysis using sputtered neutral mass spectroscopy and cross-sectional transmission electron microscopy suggested that both the diffusion of Ge into GaSb and the formation of a PdGe state were essential to the annealing processes.