Pure and Fe-doped In2O3 nanocrystalline powder was synthesized using a solution chemistry route based on the Sol-Gel process, which is a simple and inexpensive technique and produces long-time stable stock solutions. The X-ray diffraction patterns revealed the formation of nanocrystalline particle size with well-crystallized cubic bixbyte structure. The average crystal size was calculated from XRD patterns using Debye-Scherrer's equation for the (222) peak and found to be 8 nm. This observation agrees well with the particle size estimated from transmission electron microscopy (TEM). The observed Raman peaks in the doped materials are shifted towards the lower frequency up to 15 cm−1 and we did not observed any additional new Raman modes with Fe doping. This clearly indicates that Fe ions are indeed occupying interstitial/substitutional sites in the host In2O3, in agreement with XPS measurements. Magnetic properties were studied using superconducting quantum interface device magnetometer (Quantum design MPMS XL-7). Preliminary magnetic measurement results suggest the incorporation of the dopants in the diamagnetic In2O3-host structure.

Zinc oxide is increasingly being studied as an eventual replacement for indium tin oxide as a transparent conducting oxide (TCO) for thin film solar cells. In order to better understand the growth process of ZnO, as well as provide for accurate control on the National Renewable Energy Laboratory's TCO deposition system, undoped RF-magnetron sputtered ZnO films on silicon were analyzed in situ using real-time spectroscopic ellipsometry (RTSE). A large wavelength range (245-994 nm) was measured in order to derive information about optical properties both below and above the bandgap. Atomic force microscopy (AFM) measurements were also taken to confirm ellipsometry surface roughness results and provide additional insight into the surface morphology.

In light of observed poor fit of typical two-layer optical models to in situ ellipsometry data, we propose a model film structure consisting of two layers: a bulk ZnO layer of graded density that increases in thickness as the growth proceeds and a growth zone at the top of the film of approximately constant thickness with a slightly larger bandgap, lower density, and decreased excitonic absorption. Unfortunately, this model is insufficient to explain the evolution of the film during the early growth period, corresponding to film thicknesses less than 100 nm. Nevertheless, the presence of a growth zone for films above a certain thickness should provide some insight into the growth process of RF-magnetron sputtered ZnO.

Cadmium based oxide and hydroxide nanocomposites material is synthesized by pulsed laser ablation of cadmium metal in the double distilled water. A piece of cadmium metal, placed on the bottom of glass vessel containing double distilled water, was irradiated with 1064 nm of pulsed Nd:YAG laser operating at 35 mJ/pulse energy and 10 ns pulse width for 30 minutes. Colloidal solution of produced Nanoparticles is found stable for two days. Fine white colored powder is obtained after drying centrifuged solution. UV-visible absorption of colloidal solution, XRD, TGA, DTA and FTIR of the powder is used for the characterization of material. Possible mechanism of synthesis and hydroxide to oxide transition is discussed.

A new chemical synthesis route is reported for deposition of zirconia thin films having adjustable porosity with average pore size in nanometer range. Deposition method is simply a sol-gel dip coating in which HCl is used as catalyst. TEM and FTIR studies of deposited films show porous microstructure, which depends critically on ageing of sol used. The shift in binding energy of Zr 3d5/2 (at 182.4 eV) attributes the formation of zirconia. Optical results show high transmittance (> 80%) in VIS-NIR region and effective refractive indices values (neff) tend to decrease for films prepared with higher aged sol. Porosity enhancement from 15-52% is observed by neff comparing with refractive index of non porous films (nz).

Spherical submicrometer-sized titanium dioxide (TiO2 or titania) particles were prepared by the sol-gel method from hydrolysis and condensation of titanium alkoxide using different basic catalysts in ethanol/acetonitrile at different annealing temperatures. A systematic study was performed in order to determine the effect on the particle size and shape of the different reagents. Subsequently, they were deposited onto silicon wafers, in order to form a monolayer of TiO2 monodisperse particles. The titania particles were characterized by scanning electron microscopy to determine size and shape, and by X-ray diffraction to find their crystal structure.

As material processes move to the nanoscale, fine control of process chemistries becomes critical. Atomic Layer Deposition, Chemical Vacuum Deposition, and Selective Gate Oxidation, as well as fabrication of Carbon Nanotubes all need water vapor from 50 sccm (40mg/min) to below 1 sccm ( 0.8 mg/min). Water vapor can be used for oxidation, cleaning and annealing of the nanoscale devices and thin films.

At 0.8 mg/min, flow control of liquid water with a mechanical pump is difficult without pulsation. Because water is liquid at room temperature, a standard thermal mass flow controller for gas cannot be used. Instead bubblers are used. However, they do not provide consistent or repeatable delivery. They are affected by gas and liquid temperature, relative pressures as well as gas velocity, liquid height, thermal droop, and contamination build up.

RASIRC® has developed a new pervaporation device that selectively allows water to diffuse into a carrier gas stream. The liquid water never directly contacts the carrier gas, allowing for independent liquid and gas pressures. A nonporous, hydrophilic membrane provides very rapid diffusion of water vapor into the carrier gas stream. This allows for precise amounts of water vapor to be added to the carrier gas based solely on relative vapor pressures.

To validate the performance of the device at very low flow rates into both atmosphere and vacuum process pressures, a heated humidity probe was used. This device was able to measure flow rates of 1 to 200 sccm in both vacuum and atmospheric pressure. The experimental results were compared with the expected theoretical dew point to validate the procedure. The humidity probe was used to measure both long term stability of the device and the instantaneous response time. Experimental results were compared to the expected time needed to change the water vapor concentration in the test volume.

Photodeposited physical relief structures have been formed via the UV-irradiation of solutions of the heteroleptic titanium alkoxide, (OPy)2Ti(TAP)2. Raman studies of the films produced confirm the photoinitiation of hydrolysis and condensation reactions in the molecular structure, leading to the development of an insoluble solid phase. Using a shadow mask technique, these films were deposited directly from solution with microscale patterning and their structure and properties were studied as a function of both irradiation conditions (UV-fluence and intensity) as well as precursor solution chemistry (water content). Variations in nanostructure are visible in scanning electron micrographs, with a higher solution water content producing a more condensed, i.e. less porous, film.

Transparent and conductive mixtures of ITO-ZnO and ITO-ZnO:Al have been deposited by a combinatorial pulsed laser deposition on Si and quartz substrates. Measurements of the In to Zn ratios along the transversal axis of the substrates were performed using energy dispersive x-ray spectroscopy. From simulations of the x-ray reflectivity spectra, collected with a 2 mm mask on different locations along the transversal axis of the samples, the density and thickness of the deposited films were calculated and then the In to Zn ratios. The crystalline structure and electrical properties of the deposited films were also investigated along the same axis. Changes in the ratio of In/Zn along this axis resulted in changes of the lattice constant, texture, optical and electrical properties of the films. By changing the In to Zn ration we could tailor the properties of the transparent electrode and found ways to partially replace the more expensive ITO material with ZnO.

Heterojunctions composed of wurtzite-structure (piezoelectric) ZnO and perovskite-structure (ferroelectric) BaTiO3 are very interesting because of the coupling effects between the non-switchable ionic charge of wurtzite-structure and electrically switchable lattice charge of pervoskite structure at their common interface. In this paper we report the variations in the overall electrical properties of the ZnO-BaTiO3 heterostructure as a function of different physical attributes by using our previously reported physical model approach. This numerical model analysis helps us to prepare the samples by using pulsed laser deposition with specific electrical properties. This study is also useful for the future device applications.

We investigated electrical conduction of anatase Ti0.94Nb0.06O2 (TNO) epitaxial thin films in relation to oxygen defects generated by post-annealing. Annealing of TNO in oxygen was found to cause dramatic decreases in ne. Resonant photoemission spectroscopy measurements revealed that a deep acceptor state just above the top of valence band evolves, synchronized with the decrease of ne. We proposed that the acceptor state originates from interstitial oxygen atoms combined with Nb dopants and compensates electron carriers.

Strain engineering is key element for improving MOSFET device performance in today's advanced high performance microelectronics. Strained SiN layers are well established in this regard to generate near surface strain effects for carrier mobility enhancement. Non destructive detection of effects from strain layers has not been resolved yet, especially during the processing of patterned wafers. Since optical reflective measurements are well established for non destructive thickness measurements in semiconductor manufacturing, the signals out of those spectra can be used to investigate stress induced carrier mobility enhancement effects, as shown in this work. This provides direct access to the effectiveness of the applied near surface strain to the carrier mobility. By this novel method, SiN films at different stress levels and under different process conditions are investigated on silicon bulk wafers. On these wafers, the optically detected spectra shift, known as plasmon shift, can be correlated with standard wafer bow stress measurement results. These results are correlated to the electrical performance of microelectronic test structures. Based on this, the relative variation of the stress levels of SiN films after different process treatments, and the impact on carrier mobility in microelectronic devices is shown.

Small Angle Neutron Scattering (SANS) and neutron diffraction are used to probe the structure of Anodized Aluminium Oxide (AAO) in an extended Q range, from 7.10−3 to 16 Å−1. In the small angle region [7. 10−3 Å−1 − 7. 10−2 Å−1], impregnation of a D2O/H2O mixture within the AAO porous structure, leads to a dramatic decrease of the coherent SANS signal by two orders of magnitude, but perfect matching of the membrane cannot be reached. We explain such an imperfect matching by the presence of 1 nm in size Bayerite domains within the bulk of the amorphous Al2O3 matrix, as detected by Neutron diffraction in the [0.3 Å−1 − 4 Å−1] Q range. Traces of sulfur, probably incorporated during the anodic synthesis process in a H2SO4 solution, are also detected by Scanning Electron Microscopy with Energy Dispersive X-ray analysis (SEM-EDX). We estimate the AAO neutron scattering length to be 4.22 1010 cm−2. This value is an important input, when taking advantage of neutron contrast matching to probe the large scale filling homogeneity (adsorption of a liquid or deposition of a solid) within the porous structure of AAO membranes.

The crystalline structure, composition, chemical bonding and thermal stability of HfO2-Al2O3 mixtures deposited on Si using a combinatorial pulsed laser deposition technique were investigated. After deposition some films were annealed at temperatures from 850 to 950 °C for 6 or 12 minutes. Grazing incidence x-ray diffraction investigations were performed to asses the crystallinity and thermal stability of the annealed layers. Measurements of the Al to Hf ratios were performed using energy dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy. From simulations of the x-ray reflectivity and spectroscopic ellipsometry spectra the phase composition and thickness of the films was calculated and then the Al to Hf ratios. Al/Hf values of 1 and 8 were found to be necessary to block the crystallization of the films after anneals at 850 and 950 °C, respectively.

Iodine compounds have been used as X-ray contrast agents in the field of medicine, because of their low transmittance property for X-ray. The iodine compounds may provoke adverse events as allergic reactions in patients, so that they can not be administered to such people. Core-shell nanoparticles are good candidates for prevention of allergic reactions, because the shell materials can keep the contrast agents from living systems. We have proposed a method for silica-coating of iodine compounds as AgI nanoparticles. In the present work, properties of the silica-coated AgI nanoparticles such as colloidal stability, X-ray absorption and X-ray CT imaging were examined.

Silica-coated AgI nanoparticles were prepared with Stöber method, which was performed with 2.3×10-5 M MPS, 11 M water, 0.01 M DMA and 0.01 M tetraethyl orthosilicate in the presence of 5×10-4 M AgI nanoparticles that were prepared from AgClO4 and KI. The particles had an AgI core size of ca. 15 nm and a silica shell thickness of ca. 20 nm.

Since high iodine concentration in sample solution is desired for practical use as X-ray contrast agents, the colloid of as-prepared coated particles was concentrated with centrifugation. The particle colloid that was concentrated up to an AgI concentration as high as 0.4 M was colloidally stable in saline, and exhibited properties of X-ray absorption and X-ray contrasting comparable to a commercial X-ray contrast agent. Accordingly, the silica-coated AgI nanoparticles prepared in the present work are expected to be applied to a novel X-ray contrast agent.

The effects of an embedded silver layer on the electrical properties of zinc oxide (ZnO) / silver (Ag)/ zinc oxide (ZnO) layered composite structures on polymer substrates have been investigated. We have engineered transparent conducting oxide structures with greatly improved conductivity. Electrical properties are correlated with Ag thickness. Film thicknesses were determined using Rutherford backscattering spectrometry. Hall effect, 4-point probe, and UV-Vis spectrophotometer analyses were used to characterize electrical and optical properties. The results show that carrier concentration, mobility, and conductivity increase with Ag thickness. Increasing Ag thickness from 8 to 14 nm enhances sheet resistance and resistivity by six orders of magnitude. We describe of the influence of Ag thickness on electrical properties of the ZnO/Ag/ZnO composite and propose a conduction mechanism for this system.

Local phenomena like trap assisted tunneling and oxide breakdown (BD) in new high-k gate oxides in advanced MOS devices hinder the acquisition of device requirements stated in the International Technology Roadmap for Semiconductors (ITRS). Conductive Atomic Force Microscopy (C-AFM) visualizes these local phenomena by measuring the local tunneling through the dielectric. In the first part of this work we show that the physical composition of surface protrusions, that are produced at sites electrically stressed with C-AFM and that distort the electrical measurements, is oxidized Si. In the second part, we illustrate that C-AFM measurements become more reliable in high vacuum (1e−5torr) as surface (oxidized Si protrusions) and tip damage is reduced. Finally, we illustrate good agreement between conventional macroscopic electrical measurements and nanometer-scale C-AFM measurements on normal and gate – removed high-k capacitors, respectively. Moreover, to illustrate the strength of the local tunneling technique, we show the possibility of locating BD spots on a high-k capacitor.

The ultimate goal of nanotechnology is to design successful syntheses to produce nanomaterials with required properties. The properties of nanoparticles mainly depend on their size, shape and crystal structure, hence control over these factors is a major issue in this field. In this study, Co nanoparticles with four different crystallographic structures (hcp, fcc, bcc and epsilon) have been wet-chemically synthesized by varying precursors and surfactants in the reaction. Co K-edge absorption spectra were collected in transmission mode at the XMP beamline at the Center for Advanced Microstructures and Devices (CAMD). The X-ray Absorption Near Edge Structure (XANES) and Fourier Transformed Extended X-ray Absorption Fine Structure (FT EXAFS) spectra were analyzed using the “fingerprint method”, i.e. by comparing them with either standard compounds or with the simulated spectra that were calculated using the FEFF8 code. EXAFS spectra were also analyzed by fitting them with relevant crystallographic models in r-space including higher coordination shells using the IFEFFIT analysis program. All four crystal structure types were conclusively determined by using this approach.

The possibility of an A-site (La3+/Sr2+) ordering in a colossal magnetoresistance manganite (CMR) La3/4Sr1/4MnO3 was explored using molecular dynamics (MD) simulations with a newly developed force field (FF) and quantum mechanics (QM) calculations on the structures obtained from MD. The calculated degrees of stabilization (enthalpy gain) of various patterns of A-site ordering are not significant enough to overcome the accompanying entropy loss, supporting the random A-site distribution in La3/4Sr1/4MnO3. This approach combining MD and QM as well as the versatile FF developed in this study should be useful to investigate the structures and functions of magnetic tunnel junction devices involving mixed-valence manganites.