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The effect of humidity on quantitative atomic force acoustic microscopy (AFAM) measurements of elastic properties is investigated in this research. The results indicate that environmental conditions can influence quantitative AFAM measurements of nanoscale elastic properties, at least for some materials.

A detailed study of GaN pillar arrays by atomic force microscopy (AFM), Raman spectroscopy, and photoluminescence (PL) spectroscopy is presented. AFM is used to characterize the shape of the GaN pillars and revealed a large roughness of etched pillar surfaces.

Research describing the tapping mode dynamics of atomic force microscopy is presented. In particular power and harmonic balance techniques are investigated for identifying tip-sample interaction.

The capacitive force acting on the tip of an atomic force microscope has been computed and compared with the the corresponding van der Waals force. Results indicate that the force measured for tip-surface distance larger than 10 nm cannot be given in terms of van der Waals forces and have to be stated in terms of capacitive forces. This finding shows that electrostatic forces are dominant for a tip-surface distance larger than half of the tip radius of curvature.

Experimental and theoretical characterizations of the detection sensitivity of atomic force microscopes equipped with optical beam deflection for small cantilevers are presented. It is demonstrated that the signal-to-noise ratio of the detection can be raised considerably with the use of an adjustable aperture. The findings show that the aperture has increased the signal-to-noise ratio of the optimal beam deflection detection by a factor of 1.5 to almost 3.

A comparison was made between atomic force microscopes (AFM) and scanning tunneling microscope (STM) nanolithography techniques based on local oxidation of silicon. Findings showed that the STM mode is not a suitable tool for lithography on silicon, while the AFM in contact mode (CM-AFM) allows high speed and can provide thick oxide. The best compromise between STM and CM-AFM appeared to be AFM in tapping mode, which keeps fine patterns as narrow as 20 nm with relative high speed.

The limit to the resolution when optically sensing the displacements of a mechanical cantilever utilizing the the knife edge detection procedure implemented with a quasimonochromatic thermal-like optical source was theoretically examined. Results showed that superluminescent diodes can provide a minimum detectable displacement of the cantilever about 5 dBs above the shot noise for 1 mW of optical power. Also, the source induced noise is smaller than the thermal-vibration noise of the cantilever in many of the cases of practical importance.

An investigation on the validity of the profiles gathered from preferential etching and atomic force microscopy (AFM) imaging of etched optical fibers and waveguides was conducted. The optical fiber's measured geometry and the position of its lateral features were found to be independent of the etch time. Results from the study of an elliptical core fiber indicate that the refractive index profile was in qualitative agreement with the preform index profile. However, measurements obtained through AFM reveal that during the drawing process, the ellipticity of the core changed.

Computation of the eigenfrequencies of a rectangular cantilever clamped at a rigid support for the atomic force microscope (AFM) for a vacuum and for corrected flow showed a relative error less than 4% given a thickness T less than 1/20 of cantilever width. Measurements for both fluid and gaseous medium also indicated a node requirement of at least four for the eigenmode, assuming that the cantilever followed a z direction.

Force curve imaging spectroscopy produced atomic force microscope images, analogous to the combination of both forward and reverse friction images, and Z modulation images. These images were obtained for every pixel on the force-distance curve. Adhesion image meniscus force and hardness images were sensitive to XY tip motion.

The static deflection of cantilever type plates in an atomic force microscope was theoretically investigated using an approximate analytical analysis and a rigorous finite element analysis. It was shown that in the case of an arbitrary cantilever plate with a small anticlastic curvature, the zeroth order approximation was relatively accurate with an error of approximately 13%.

The use of van der Waals force manipulation to enhance the imaging resolution of an atomic force microscope was investigated. In atomic force microscopy, long range interactions such as van der Waals forces indicate that the macroscopic tip radius is the primary determinant of image resolution. The results showed that immersion of both the tip and the sample in an appropriate fluid allows the van der Waals force to be eliminated and thus improve the relatively coarse image quality of atomic force microscopy.

Atomic scale friction resulting from contact between a diamond tip and diamond (100) and (111) surfaces was investigated using an ultrahigh vacuum force microscope. The results showed that on the (100) diamond surface, the frictional force featured periodic characteristics which were associated with a reconstructed surface convoluted over an asymmetric tip configuration. In the case of the (111) diamond surface, friction was not associated solely with the surface structure.

The magnetic force microscope (MFM) is a version of the atomic force microscope which utilizes a magnetic tip placed close to the sample that interacts with the stray field emanating from the sample substance. A study was conducted using different tip models in order to calculate the stray magnetic field of the tiny tip used in the MFM. Best results were obtained from the use of nonmagnetic tips covered by a magnetic thin film to improve the lateral resolution of the MFM. A quantitative relationship was applied directly that conforms to the shape limitations of the model.

A comparison of a Michelson interferometer and an optical beam deflection configuration used in atomic force microscopy showed that both exhibit similar sensitivities. Signal-to-noise ratio calculations for the optical beam deflection technique showed the values are sufficient to attain atomic resolution. It was also shown that the deflection setups use less optical components and are easier to align.

A scanning magnetic microscope that has a photoluminescence nanoprobe implanted in the tip of an atomic force microscope, (AFM) scanning tunneling microscope (STM), or near-field scanning optical microscope, and exhibits optically detected magnetic resonance is proposed. The proposed spin microscope has nanoscale lateral resolution and the single spin sensitivity for AFM and STM.

The atomic force microscopy (AFM) lithography in La0.8Ba0.2MnO3 (LBMO) films is explored. Grooves are directly obtained with poor controllability and reproducibility under a positive sample bias voltage whereas controlled nanosized patterns are produced with excellent reproducibility and a high etching selectivity under a negative sample bias voltage.

A study was conducted on tip artifacts in atomic force microscope images of nanometer-scale cellular structures formed on germanium surfaces by ion bombardment. The results indicate that severe image distortion when the tip size is comparable with the mean cell/hole diameter results in the appearance of a columnar/granular morphology. Image inversion can ofter deconvolute these tip artifacts.

Tunneling atomic force microscopy (TUNA) is used for describing the charge trapping in high-k Zr[O.sub.2] dielectric stacks at nanoscale dimensions by analyzing the alteration of the I-V curves and the I-V hysteresis phenomena. The effect of the thin Si[O.sub.2] interfacial layer thickness and its modification with annealing conditions on the electrical properties is examined.

Surface nanostructuring with lateral resolutions beyond the capabilities of conventional optical lithography techniques is demonstrated. The main reason for the highly localized nanostructuring achieved with this technique was found to be the enhancement of the electric field in the tip-sample gap.

Preparation of BaTi(sub 1-x)Zr(sub x)O(sub 3) thin films by a soft chemical method and deposited by the spin-coating technique is described. atomic force microscopy analyses revealed that the surface roughness and the grain size of BaZr(sub x)Ti(sub 1-x)O(sub 3) thin films decrease as the Zr concentration increases upto 0.15.

The study of phase transformation in the nanoidentation of Si by conducting atomic force microscopy is reported. The observations show distinctively high current features with smallest size around 20 nm and correspond directly to the generated conductive Si-III and /or Si-XII phases under pressure release.

An array of exchange biased spin-valve giant-magnetoresistance nanopillars is fabricated and the current I dependence of the resistance R is investigated using an electrically conducting atomic-force microscope (AFM) probe contact at room temperature. The findings show a current inducted switching in MnIr/CoFe/Cu/CoFe/NiFe nanopillar using the AFM probe contact.

Atomic force microscopy (AFM) probes were characterized at low temperatures and three different types of triangular cantilevers for contact mode were studied at low temperatures. Micrographs of coated cantilevers imaged in a scanning electron microscopy at low temperatures confirm itEs bending due to a slight difference in the thickness of the metal coating of the cantilever.

An explicit expression for the atomic force microscopy-induced electric field in a ferroelectric thin film is reported. Based on this approach, the depolarization field and the energy created by the polarization charges for different substrates can be studied.

The propagation of errors in the inverse problem of scanning force microscope (SFM) measurement is investigated. This provides a cantilever deflection signal based on known forces with which to evaluate the accuracy and precision of a force reconstruction algorithm.

Applied voltage dependence of nano-oxidation of ferromagnetic thin films using atomic force microscope is discussed. Theoretical analysis suggested that the size of the nanostructure did not depend on the distance between the cantilever and film surface, but significantly depended on the curvature radius of the cantilever.

Ferromagnetic bilayer thin film samples of the well characterized CoPt/Co bilayer exchange-spring system is discussed to supply experimental and theoretical estimates of the exchange field supporting the interfacial exchange coupling across the interphase interface. The surface roughness of the films as measured by atomic force microscopy of the CoPt layer is approximately 1.4 nm.

Structural imperfections on the nanometer scale act as imperfect corners and rough electrode boundaries cause junction specific magnetic switching behavior. Micromagnetic numerical simulations with the real atomic force microscopy (AFM) shape show that these individual details significantly influence the nucleation, location, and mobility of domain walls.

A careful study on the final shape of the InAs nanostructures cooled fewer than three different conditions with P(sub 2), As(sub 2), and no Group V overpressure, using reflection high-energy electron diffraction (RHEED), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The results show that morphological studies considering the grown surface that do not take into account post growth processes can be misleading to understand the growth mechanism governing the self-assembling process.

The importance of mechanical force in microelectromechanical systems and in atomic force microscopy is presented. A theoretical discussion of the magnitude of the forces and the conditions where they can be encountered is discussed.

A general theoretical model for the frequency response of a cantilever beam executing torsional vibration in a viscous fluid is presented. This model is applicable to a cantilever beam of arbitrary cross section that is excited by an arbitrary torque, and immersed in a fluid of arbitrary viscosity and density.

A study was conducted, using atomic force microscopy and scanning tunneling microscopy (STM), to investigate the surface of epitaxial MnAs layers grown on GaAs(001) substrates by molecular neam epitaxy. The result reveals that both the terrace-step morphology and the surface reconstruction on the ridges and in the grooves are independent from the ridge-groove structure.

It is a determination of the exact ion beam shape by the evaluation of high-energy focussed ion beams (FIB) patterned single spots and a beam shape evaluation method is introduced. It is shown that the proposed method is directly related to the ion beam profile.

It is a study of the kinetic surface roughening of sputter-deposited titanium nitride (TiN) thin films on silicon substrates. It is verified that the surface growth behavior of the TiN thin films is due to noise-induced roughening with surface diffusion as the relaxation mechanism.

Carbon nanotubules deposited on a silver surface is measured by an atomic force microscopy. It is shown that SERS is sensitive to factors like excitation wavelength, the electronic structure of the adsorbate and the shape and dimensions of the colloidal particles.

A study was conducted, using the combined application of atomic force microscopy, cross sectional high-resolution transmission electron microscopy and x-ray diffraction, to examine the initial growth mechanism of epitaxial BaTiO3 films on (001) SrTiO3 substrates. The result reveals important features of the growth mechanism of epitaxial BaTiO3 films of different nominal thickness.

An experiment was conducted, using diffuse x-ray resonant magnetic scattering, atomic-force microscopy, and magnetic hysteresis measurements, to explore the relationship between the roughness and magnetic properties of interfaces between magnetic and nonmagnetic thin films. The result reveals that some volume of a magnetic film bordered by a nonmagnetic film does not respond to applied-magnetic fields, which are at least ten times the strength needed to align the bulk moments.

A study was conducted, using scanning electron microscopy, scanning Auger microprobe, x-ray diffraction (XRD), cross-sectional transmission electron diffraction (XTED), atomic force microscopy, vibrating specimen magnetometer, and I-V characteristics, to examine the structure and properties of the Fe-O/AlO(sub x)/Fe-O tunnel junctions. The grain shape properties and stress features of these junctions are explained with results.

A study was conducted, using conductive atomic force microscopy, to investigate the characteristics of dislocation-related leakage current paths in AlGaN/GaN heterostructure grown by molecular-beam epitaxy and their mitigation by local surface modification. The result reveals the leakage paths associated with screw and mixed dislocations, based on observations of the surface morphology.

A study was conducted, using atomic force microscopy, Raman spectroscopy and x-ray photoelectron spectroscopy, to investigate the initial nucleation of diamond film on a Si substrate, deposited by a three-step growth process together with a cycle bias enhanced nucleation (BEN) growth/H2 plasma etching technique in a microwave plasma enhanced chemical vapor deposition system. The results indicate that the SiC and a-C layers are formed by the carburization step and then nondiamond components.

A technique to excite the self-oscillation of a commercially available metal-coated cantilever and detect the deflection simultaneously with only a single optical fiber is discussed. The result confirms that there exists a threshold value for the feedback strength to excite the self-oscillation as discussed in the theory.

The nonlinear equations of motion for a silicon cantilever beam, covered by a piezoelectric lead-zirconite-titanate layer, subjected to a Lennard-Jones type boundary condition, are formulated for voltage excitation. The frequency shift of individually piezoactuated microbeams is determined.

The small amplitude thermal vibrations of the microcantilever of an atomic force microscopy can be enhanced via a delayed feedback system. The proposed model using the beam equation is able to predict a range of allowed frequencies that is much narrower than that predicted by the point mass model.

A comparison study of topographical and electrical properties of hydrogenated and oxidized high-quality B-doped homoepitaxial films is carried out by conductive atomic force microscopy. It is observed that the topography images of both hydrogenated and oxidized films show nanoscale flatness and uniformity.

The surface morphology evolution of amorphous SiO2 thin films deposited by ultrahigh vacuum radio frequency magnetron sputtering is studied by atomic force microscopy. The results show that the surface roughness of the deposited films reduced with increased substrate temperatures.