Electromigration during accelerated testing can induce early stage plastic deformation in Al interconnect lines as recently revealed by the white beam scanning X-ray microdiffraction. In the present paper, we provide a first quantitative analysis of the dislocation structure generated in individual micron-sized Al grains during an in-situ electromigration experiment. Laue reflections from individual interconnect grains show pronounced streaking after electric current flow. We demonstrate that the evolution of the dislocation structure during electromigration is highly inhomogeneous and results in the formation of unpaired randomly distributed dislocations as well as geometrically necessary dislocation boundaries. Approximately half of all unpaired dislocations are grouped within the walls. The misorientation created by each boundary and density of unpaired individual dislocations is determined.

We have investigated the reproducibility of micro- and nano-scale measurements of sheet resistance performed with micro-fabricated multi-point probes. The probes consisted of Au coated SiO2 cantilevers extending from a Si base. The measurements were done with a four-point probe technique on thin Au films, the probe electrode spacing ranging from 18 μm to 1.5 μm. We find that the standard deviation of repeated sheet resistance measurements ranges from 0.2% at 18 μm spacing to 2.6% at 1.5 μm spacing. It is inversely proportional to the probe electrode spacing. This behaviour is expected if the resolution of the measurements is governed by the positional errors of the probe electrode tips. The corresponding standard deviation of the probe tip positions (in both lateral directions) is calculated to be approximately 20 nm. We argue that these positional errors depend on the probe cantilever amplitude at the time of contacting the surface. The amplitude is inversely proportional to the square root of the cantilever spring constant, indicating that stiff cantilevers give the best reproducibility. We estimate the limiting reproducibility of multi-point probes with nano-scale electrode spacing.

Recently, there has been great interest in physico-chemical treatment for modifying polymer surfaces. UV Excimer laser irradiation is of particular interest in morphological and chemical modifications. Depending on the laser energies used, effects of laser treatment fall into two groups: above the ablation threshold the ripple structures of micrometer size form (high-fluence), and below the ablation threshold the sub-micron structures emerge (low-fluence).

Traditional methods of studying chemical properties are Fourier-transform infrared spectroscopy, x-ray photoelectron spectroscopy, and mass spectroscopy. The ability of a relatively new technique involving chemical force microscopy (CFM) can be used to image and discriminate the areas exposing different functional groups on polymers. Gold-coated AFM tip modified with carboxylic acid (-COOH) terminated self-assembled alkanethiol monolayers (SAMs) was used to measure the adhesive forces between the tip and the laser treated samples in a water or hexane medium.

The CFM results showed that high-fluence laser treated polyamide has the highest adhesive force with the modified tip in a water medium when compared with the control and low-fluence ones. The adhesive force is due to electrostatic attraction between the negatively charged tips terminating in COO- groups and the positively charged sample terminating in NH+ groups. This indicates that the high-fluence laser treated sample results in the formation of many amine end-groups on the polymer surface. In comparison, only low-fluence treated surface shows adhesive force with the modified tip in a hexane medium. This implies that the low-fluence laser treated polyamide has substantially more hydrophilic groups than the untreated and high-fluence laser treated samples. The adhesion force measurements by CFM allow one to have better understanding of surface chemical modifications induced by UV excimer laser.

The luminescence of titanium oxide and tin oxide has been investigated by cathodoluminescence in the SEM, as a function of the structural changes induced by thermal treatments. The evolution of the luminescence of TiO2 rutile, anatase and mixture phase with the annealing temperature is related to the process of thermal induced grain texture and to transition of metastables phases to the stable rutile. The emission band is peaked at 480 nm for the composite phase and at 580 nm for anatase and rutile phases respectively. A broad band in the 520–560 nm region is present in the spectra of both anatase and rutile phase. Thermal annealing leads to a red shift of the luminescence emission, with the emission band peaked at around 820 nm. In sintered tin oxide the main emission bands appear centered at about 480 nm and 630 nm. The intensity of these bands increases with annealing temperature up to 1200°, whereas for samples annealed at 1500° these emissions are quenched. Mechanical ball milling has been used to produce nanocrystalline SnO2 grains to investigate the influence of the presence of nanocrystals on the CL emission.

Stratum corneum acts as a barrier to protect our body, as well as a pathway for conducting skin sensations. Understanding the mechanical properties such as elasticity, yield stress, of stratum corneum is important to improve and develop new products in the personal care industry. In this work, structural properties of stratum corneum are studied by atomic force microscopy (AFM) imaging to reveal surface structure of stratum corneum. To study mechanical properties, AFM force measurements and nano-indentation techniques were used to characterize elastic properties of dry and wet stratum corneum. Nano-DMA measurements were also conducted to characterize visco-elastic properties of the same material.

SPM/SEM-hybridsystems are more than only a combination of complementary microscopy techniques, because the used probes can simultaneously either be used as sensors, which give access to a vast variety of material properties, or as actuators, which can deliberately modify samples properties. The wide application field as well as flexibility is demonstrated exemplarily on techniques in microanalyses like nano-probing, cathodoluminescence, electron beam induced currents, and thermal analyses. These results provide an interesting perspective with respect to failure analyses and reliability of modern materials and devices.

We have conducted an investigation using TEM, XRD and synchrotron based X-ray absorption fine structure (XAFS) to probe the structural and electronic characteristics of several molecularly capped metal nanoparticles (NPs). Three series of NPs were employed in the XAFS study to address the effect of nano-size, metal-core and capping molecules on the structure and properties of the NPs. They are (1) thiol-capped Au NPs from 1.6nm to 4.0nm, (2) thiol-capped Au and Pd NPs of ∼2nm and (3) Au NPs of ∼4nm capped by thiol and tetraoctylammonium bromide (TOAB). The results on their local structure, bonding and d-charge distribution are presented.

A new transmission electron microscope equipped with a monochromator and a high resolution energy-filter was used for the first time to fully exploit the chemical bonding information contained in the near edge fine structures (ELNES) of electron energy-loss spectra. The instrument is capable of acquiring spectra with an energy resolution in the range of 0.1 eV, thus opening up the way for improved ELNES information. ELNES spectra of TiO2 and CoO have been recorded and are compared with data obtained with a conventional microscope and with x-ray absorption spectroscopy. In case of the L2,3 edges of the transition metals the new instrument revealed previously unobservable fine structure details, but for the O K edges the improved energy resolution does not result in more detailed structural features than observable in common microscopes. Furthermore, the potential of the new microscope to obtain chemical bonding information at the nanometer scale is discussed.

Molecular Dynamics simulations are used to explore the short-time dynamics of nanoscopically confined poly(ethylene oxide). Both bulk and confined systems have been studied using an atomistically detailed force field so as to comparatively illustrate their differences and complement experimental results. Our aim is to elucidate the origins of the counter intuitive distribution of relaxation times for C-H bond reorientation for PEO in severe confinements, as experimentally observed in solid state 2H NMR studies. In contrast with the respective bulk PEO system, where a transition from distinct solid to liquid like dynamics is seen with increasing temperature, for the confined chains there is a coexistence of fast and slow segmental dynamics over a wide temperature range. Our studies have revealed that factors such as local density inhomogeneities, proximity of Li+, and translational motion, synergistically contribute to the generation of fast PEO segmental dynamics in 1nm confinements.

Aluminum silicate nanoaggregates grown on organic multilayer templates were imaged by a transmission electron microscope. Images were processed by fractal and FOURIER analysis. The estimated mass fractal dimension suggested that aggregate formation was diffusion limited. Nonlinear filtering of FOURIER spectra, which included comparison with a model spectral density, yielded «enhanced power spectra». Some morphological descriptors were extracted from the latter. The main result, materials classification, was attained by a two-scale procedure. Some descriptors were related to the material properties such as nanoparticle size distribution and sharpness of aggregate boundaries.

Strained-Si-On-Insulator (Strained-SOI) MOSFETs are one of the most promising device structures for high speed and/or low power CMOS. In realizing strained-Si MOS LSI, fabrication of strained-Si MOSFETs with small sizes are indispensable and thus, the investigation of the strain relaxation is an important issue. Therefore, the strain relaxation of strained-SOI mesa islands with small active area was investigated in this study. Thin strained-Si films were grown on thin relaxed SiGe-on-insulator (SGOI) structures (x=0.28). The isolation process was carried out by using chemical-dry-etching (CDE) to fabricate samples with small active areas. Using Raman spectroscopy with resolution of > 1 micron meter, strained-Si islands on SGOI substrates with the size of 5 micron meter square were investigated. Rapid-thermal-annealing (RTA) in N2 atmosphere was performed to study the strain relaxation during heating processes. As a result, it was confirmed that the strained-Si layers grown on relaxed SiGe (x=0.28) before and after mesa isolation, down to 5 micron meter in size, had almost no relaxation after the RTA process at 1000°C. Furthermore, it was confirmed that the nano-beam electron diffraction (NBD) measurement showed similar tendency regarding the strain relaxation.

We have investigated the conductivity variation of copper phthalocyanine nano-crystals deposited on SiO2 and mica. The density of surface hydroxyl group on SiO2 was estimated to be more than 10 times larger than that on mica by X-ray photoelectron spectroscopy. The grown crystals on both substrates were categorized to be a-axis orientation of α–form. Conductance-distance (G-d) measurements for various crystalline grains having different heights have been carried out with current imaging using atomic force microscope. The obtained conductivity vs. crystal height plot indicates that lower height crystals have higher conductivities on both surfaces. Besides, the lower height crystals on SiO2 have higher conductivity than those on mica. These results suggest that the electrons in the bottommost molecular layer are transferred to the electrophilic functional groups on the substrate surface. Such a phenomenon at organic semiconductor/insulator interface is reported for the first time.

Epitaxial Lateral Overgrowth (ELO) is an effective method to reduce dislocations in heterostructures with large lattice mismatch. This method has been widely used to improve the quality of GaN layers. We present herein a study of the properties of ELO GaN layers grown by HVPE from an MOVPE GaN buffer layer. Cathodoluminescence shows a strong enhancement of the luminescence emission in the ELO regions, where TEM has proven the absence of dislocations. Local cathodoluminescence spectra show that this enhancement is mostly due to the yellow luminescence band. Besides Donor-Acceptor Pair recombination bands are observed in the near band gap spectral range. Raman data show that the ELO layers present a good crystalline quality. The Raman spectra did not reveal the presence of free carriers in concentration high enough to allow the presence of Longitudinal Optic Phonon Plasmon Coupled modes. The results are discussed in terms of the incorporation of impurities in the ELO layers together with the formation of compensating deep acceptors, probably VGa.

Distribution of nitrogen in the thin silicon oxynitride films (less than 5 nm) obtained by plasma nitridation of SiO2 has been studied by non-destructive angular dependent XPS. For obtaining information about the element distribution in-depth the regularization technique has been applied. It is shown that the depth of nitrogen penetration increases with decreasing the SiO2 film thickness. In this case the maximum of the nitrogen distribution is enhanced and shifted to the Si-SiO2 interface. The results are compared with depth-profiling obtained by sputtering and wet chemical etching. The dependence of the binding energies on the film thickness has been studied. The influence of different factors on the chemical shift in the ultrathin films has been analyzed.

The lattice images of the new type (cup-stacked type) carbon nanofibers were observed by high resolution transmission electron microscopy (HRTEM) and the detailed structure was analyzed by image processing. The angle of opposed graphitic basal planes was measured from power spectrum obtained by 2 dimensional first Fourier transform. The structures of the slanted (00·1) lattice planes, which appear at the cross section of the fiber wall, were shown by means of this image analysis technique. Defects were observed in the ordered structure of this material. The (00·1) lattice planes show large fluctuation in alignment of them and the (10·0) lattice planes make several angles with the (00·1) lattice planes. The average repeat distance d002 was estimated on the basis of d100 by HRTEM image and image analysis.

TiO2 is a very important material from the perspective of photocatalytic applications, but due to its 3.2 eV bandgap, it is not possible to make this material efficient under visible illumination. Anatase TiO2 nanoclusters in the 3 – 30 nm range have been formed by a wet chemical technique and surface modified in order to enhance the absorption of visible light. Nitridation of the highly reactive TiO2 nanosphere surface has been achieved by a quick and simple treatment in alkyl ammonium compounds and the metallization of this surface has been achieved by electroless plating. Although the structure of the resultant material remains anatase, some of the treated material exhibits strong emission between 550–560 nm, which red shifts and drops in intensity with aging in the atmosphere. Electron Spin Resonance performed on these samples identify a resonance at g=2.0035, which increases significantly with the nitridation step. This resonance is attributed to an oxygen hole center created near the surface of the nanoclusters, which correlates well the noted optical activity.

One of the key limiting factors in current-based scanning probe microscopies (SPM) is the quality of tip-sample contact and stray capacitance in the probe-surface junction. We conduct impedance spectroscopy over a broad frequency range (40Hz∼110MHz) through an AFM tip to quantify local electrical properties. Equivalent circuit for the tip-surface contact is constructed based on the impedance data and is used to study the mechanisms of relaxation in the near-tip region. Relative contributions of tip-surface contact and materials properties to the signal are discussed. This technique, referred to as Nanoimpedance Microscopy/Spectroscopy, is demonstrated in the imaging of an electronic ceramic: a ZnO varistor. Analysis of impedance spectra allows separation of tip-surface interactions and grain boundary behavior.

We present evidence for the operation on reconstructed Au(001) of a novel mechanism, involving dislocation motion, which is much more efficient than surface diffusion to redistribute mass around nanoindentations. Cross-slip of individual dislocations generated around the indentation point, with a screw component perpendicular to the surface, is shown to be responsible for the generation of multiple-storied, crystallographically-oriented terraces around the nanoindentation points. We also show that standard dislocation theory can be used to quantitatively describe the characteristics of the dislocations involved in the different processes around the nanoindentation.

Metal doped nanoporous carbon(NPC) materials, based on polyfurfuryl alcohol and polyethylene glycol were synthesized using new method. The characterization were carried out using acid-base titration, PXRD, TEM, diffused reflectance FTIR, SEM and mass spectrometer. Their gas phase catalytic activities were checked by passing CO and H2 through the catalysts. Carbondioxide and methane were the evolved gases when CO was passed through the catalyst, whereas carbonmonoxide and methane are the resultant gases when H2 was taken up by the catalyst.

In Integrated Circuits failure analysis excessive power supply current flowing into the IC is often used to indicate the presence of a faulty device. Location of these faulty devices can be problematic as the devices are often buried under several layers of conducting interconnect. By imaging the magnetic field produced by current flowing in an IC a faulty device can be located. In this paper we present experimental results on imaging current-carrying faults on integrated circuits using Magnetic force microscopy. We have experimentally determined that MFM is capable of measuring currents as small as 1 to 10 microampere on ICs in a 30 Hz bandwidth. We have carried out modeling calculations comparing the simulation results with experimental results using realistic MFM tip geometry. From these results we have devised a method to accurately locate the position of the internal current carrying faults from MFM images with micrometer uncertainty.