References

Phys., 109 (1938) 553. 2. A. V Crewe and J. Wall, J. Mol. Biol., 48 (1970) 373. 3. A. V Crewe, J. Wall and J. Langmore, Science, 168 (1970) 1333. 4. J. M. Cowley, Micros. Res. Tech., 46 (1999) 75. 5. J. M. Cowley, Appl. Phys. Letts., 15 (1969) 58. 6. E. Zeitler and M. G. R. Thompson, Optik 31(1970), 258 and 359. 7. A. Strojnik, Scanning Electron Microscopy 1981 1, SEM Inc., AMF O'Hare (Chicago) OmJohari, Ed., (1981), 117 and 122. 8. C. Elibol, H.-J. Ou, G. G. Hembree and J....

Introduction

Microscopy is the characterization of objects smaller than what can be seen with the naked human eye, and from its inception, optical microscopy has played a seminal role in the development of science. In the 1660s, Robert Hooke first resolved cork cells and thereby discovered the cellular nature of life 1 . Robert Brown's 1827 observation of the seemingly random movement of pollen grains 2 led to the understanding of the motion that still bears his name, and ultimately to the formulation of...

Historical Development Of Ebsd

This technique has had many different names over the past 40 years. The original developers called them high angle Kikuchi patterns (HAKP) 6 . Others have used electron backscatter patterns (EBSP), electron backscatter diffraction (EBSD), and backscattered electron Kikuchi diffraction (BEKP orBKD). We will use the terms electron backscatter diffraction to describe this technique. The first EBSD patterns were observed over 40 years ago and were termed high angle Kikuchi patterns. This was almost...

Jingyue

INTRODUCTION SCANNING ELECTRON MICROSCOPY AND NANOTECHNOLOGY Ultimately, all materials, organic or inorganic, have their origins in the collective assembly of a small number of atoms or molecules. Human beings have been fascinated by the interior world the secrets of cells and the building blocks of matter. Ever since various types of microscopes were discovered, they have been the primary instruments for helping us to directly observe, understand, and manipulate matter or cells on an...

Electron Beam Resists

EBL is classified as a reactive processing in terms of Electron Beam Processing. In this process, ionization and excitation of constituent molecules of the material occur during the scattering of the incident electrons. Some excited molecules lose their energy by collisions with other molecules and change into radicals. All these ions, excited molecules, radicals, and the secondary electrons are called active species that induce chemical reactions inside the material. Electron beam resists are...

Hrtem And Nanotechnology

With the rapidly escalating attention recently being given to nanoscale science and technology, techniques capable of structural characterization on the nanometer scale have central importance. The high-resolution transmission electron microscope (HRTEM) has evolved over many years to such an extent that resolving powers at or close to the one Angstrom (0.1 nm) level can nowadays be attained almost on a routine basis. Using correct operating conditions and well-prepared samples, highresolution...

Instrumentation of Scanning Thermoelectric Microscopy

After the invention of the scanning thermal profiler, in early 1990s Williams and Wickramasinghe reported a novel method called Scanning Chemical Potential Microscopy (SCMP) for mapping the local chemical potential, essentially thermoelectric power, of a MoS2 and a graphite sample 12 . In their experiment conducted in air, an atomically sharp metal STM tip was scanned on the surface of the sample at a constant height using a unique feedback control loop. In this feedback loop, the voltage is...

Tomography

Before describing the technique in detail, it is worth spending some time reviewing the birth and subsequent development of tomography, and of electron tomography in particular. The need to obtain 'structures' using data of lower dimensionality is present in many different fields of physical and life sciences. It was in the field of Astronomy that in 1956 Bracewell 25 proposed a method of reconstructing a 2D map of solar emission from a series of 1D 'fan beam' profiles measured by a radio...

Surface Structure Determination By Scanning Tunneling Microscopy

As a microscope, STM can provide very high resolution images in real-space. These images can be used to investigate surface structures, and also surface or even subsurface atomic dynamic processes. Before the STM was invented, surface structures were very difficult to be determined by conventional surface analysis techniques, such as low-energy electron diffraction (LEED), reflected high-energy electron diffraction (RHEED) and X-ray diffraction etc. Besides, these traditional techniques focus...

Alkanes Polyethylene and Fluoroalkanes

To demonstrate the capabilities of AFM for studies of self-assembly and order in ultra thin layers we will consider several results obtained on alkanes of different length and single crystals of polyethylene (PE), one of the most important industrial polymers. When alkanes are deposited on graphite by spin casting oftheir diluted solutions, they form layers with the well-defined epitaxial order as shown in the images of C36H74, Figures 16a-b. The domains with differently oriented striped...

Aberration Corrected HRTEM

Compensation of the spherical aberration of the objective lens offers the exciting prospect of directly interpretable image detail extending out to the HRTEM information limit without the need to unscramble the artefactual detail normally caused by TF oscillations. One additional benefit of the aberration-corrected HRTEM is that image delocalization, which is a major source of imaging artefacts at discontinuities such as interfaces and surfaces, is markedly reduced 147, 157 . Another benefit is...

Nanoscale Chemistry 51 Nanoscale Oxidation

Figure 11A shows an example process of nano-oxidation. When the tip is in contact with surfaces under ambient conditions, they are connected through a water meniscus. - - Figure 11. (A) Schematic diagram depicting nano-oxidation process on hydrogen-terminated silicon surfaces. The water meniscus works as a nanoscale reaction chamber. (B) An array of cantilevers with integrated actuators and sensors. The cantilevers are spaced by 200 0m. Adapted with permission from 85 Appl. Phys. Lett. 72...

Info

Intensities of the M5 and M4 white lines as ceria is heated from room temperature to 700 C. There are several different methods of extracting the variation of the white-line intensity in order to determine the occupancy of the 4f band 57 . Some of these methods require significant spectral processing and impose restrictive conditions on the data acquisition. However, in the Ce system, the change in the white-line intensity is pronounced and thus we can use a simplified procedure to quantify...

SRM2063a

EELS spectrum of NIST Standard Reference Material 2063a (Thin Glass Film) showing core edges for Mg K and Si K edges edges (Leapman and Newbury, 1993). superimposed upon the same beam electron, which has the effect ofdegrading the specific detail at an excitation edge or other feature. Multiple inelastic scattering increases with thickness. With sufficiently thin specimens where the inelastic scattering consists of, at most, single events per beam electron, the excitation edges...

MEED and MEEM

The severe fore-shortening of REM and SREM images may be avoided, to some extent, if the angles of diffraction by the surface planes are increased by decreasing the beam voltage and so increasing the wavelength. A number of medium-energy instruments operating in the range of5 to 20 keV have been constructed for diffraction (MEED) and scanning microscopy (MEEM) 8 10 . With the simpler electron optics and the more compact design possible for this energy range, it was easier to produce systems...

Sample Preparation Of Nanomaterials For Ebsd

The main sample preparation requirement for EBSD studies is that the sample surface shall be clean, representative of the bulk of the material and free from damage or deformation resulting from the preparation process. Some materials, like epitaxial or heteroepitaxial layers may require no additional sample preparation steps and EBSD patterns may be obtained from the sample in the as-deposited condition. Other samples may require more complex procedures to produce good samples for EBSD. For...

Eleftrojtprohe Aperture mrad

C. 1 raft p 5x10s Acm -fr J Ce 1 raia K JOkiV AE 0.5 tV Figure 8. Plots (a) show the dependence of the probe size on the probe-aperture angle for diffraction-limited probe, spherical aberration limited probe, chromatic aberration limited probe, and the root mean square sum of these contributions for 1-keV and 30-keV electrons, respectively. Plots (b) show the dependence of minimum probe size on the primary electron energy based on the root mean square (RMS) rule and the root power sum (RPS)...

Nanoscale Pen Writing 21 Dip Pen Nanolithography

The dip-pen nanolithography (DPN) process is a direct deposition technique 13 16 . It utilizes an AFM tip as a nanoscale quill pen, molecular substance as ink, and solid substrates as paper. Figure 2A shows the basic mechanism of DPN as well as approximate dimensions of commonly used pen and ink molecules. When the molecule-coated tip is in contact with the substrate, ink molecules thermally diffuse out onto the substrate and form molecular patterns. Under ambient conditions, water condenses at...

Origin Of Ebsd Patterns

EBSD patterns are obtained in the SEM by illuminating a highly tilted specimen with a stationary electron beam. Currently two mechanisms may describe the formation of EBSD patterns. In one description, the elastic scattering of previously inelastically scattered electrons forms the patterns. These backscattered electrons appear to originate from a virtual point below the surface of the specimen. Some of the backscattered electrons will satisfy the Bragg condition 6 and 6 and are diffracted into...

Image Viewing and Recording

Image viewing or recording should not normally be expected to affect resolution limits of the HRTEM but the recording media must still be properly optimized to ensure efficient operation. Ideally, every incident electron should be detected but readout noise and shot noise could affect the overall recording efficiency. The low-light-level TV camera has steadily evolved to the point where it has replaced the fluorescent screen for most image viewing. A camera is easily attached beneath the...

Christian Colliex And Odile Stephan

INTRODUCTION EELS AND NANOTECHNOLOGY Several challenges face materials science at the beginning of the 21st Century. Among them particular attention should be devoted to understanding a material's behavior from the atomic nanolevel via microstructure to macrostructure levels. Knowledge of materials at the nanoscale and control of the structural and functional properties of newly synthesized materials constitute key issues for technological progress and opening up of new markets in many major...

Lorentz Microscopy

The magnetic structure first observed through microscopy was a domain wall structure with an inhomogeneous dispersion of ferromagnetic fine particles covering the specimen Bitter method 20 . This method has also been extended to electron microscopy 21 . However, this method does not allow iterative observation of the same specimen. Lorentz microscopy, in which the specimen need not to be decorated with magnetic particles, has been used to directly reveal domain structures in thin films as a...

Energy keV

Energy distribution of backscattered electrons for normal incidence and a 70 sample tilt. for EBSD measurements. For this reason, when studying nano-crystalline materials, an SEM with a field emission source must be considered mandatory for producing EBSD patterns. Although EBSD is a technique that utilizes backscattered electrons, the resolution of the technique is generally much better than can be achieved with standard backscattered electron imaging in the SEM. This is a direct...

Recent Developments

In traditional surface analysis techniques, the sample is probed by means of electrons, photons, ions, and other particles with a spatial resolution determined by the spatial extent of the probe beams. Therefore, atomic resolution is very difficult to achieve with the conventional techniques. In contrast, with atomic-resolution, STM is based on a totally different principle, in which a local probe very sharp tip , precise scanning, and an electronic feedback are combined subtly. To achieve the...

S. N. Magonov N. A. Yerina

Gerber and E. Weibel, Phys. Rev. Lett. 49 1982 , 57. 2. G. Binnig, C. Quate and Ch. Gerber, Phys. Rev. Lett. 56 1986 , 930. 3. S. Alexander, US Patent 4,369,657, filed July 25, 1981. 4. S. Alexander, L. Hellemans, O. Marti, J. Schneir, V. Elings, P. K. Hansma, M. Longmire and J. Gurley, J. Appl. Phys. 65 1989 , 164. 5. Y. Miyahara, M. Deschler, T. Fujii, S. Watanabe and H. Bleuler, Appl. Surf. Sci. 18 2002 , 450. 6. Q. Zhong, D. Innis, K. Kjoller and V B. Elings...

Radiation Damage

Interactions between the highly energetic electron beam and the sample within the electron microscope are always likely to result in permanent structural modification. There are two basic types of electron beam damage 166 radiolytic processes sometimes known as ionization damage involve electron-electron interactions and affect most covalent and ionic solids and direct atomic knock-on displacements, which occur above characteristic energy thresholds. An electron energy of 400 keV is sufficient...

Eftem Tomography

With the advent of both post-column and in-column energy filters 102 , energy filtered transmission electron microscopy EFTEM has become a routine analytical tool that allows rapid quantitative mapping of elemental species over wide fields of view with a spatial resolution of 1 nm. 103 105 . If an energy slit window is used that allows only the zero-loss part of the spectrum to be transmitted then images can be formed using only predominantly elastically-scattered electrons typically 5 eV . By...

The Stobbs Factor

It has become increasingly obvious, and highly disconcerting, that there are substantial, seemingly inexplicable, discrepancies between the contrast levels of experimental and simulated images as well as diffracted beam intensities 161 . These differences were not apparent in earlier qualitative studies using photographic film when there was no simple measure of absolute intensity, and the contrast range in image simulations could easily be scaled to match that of the experimental micrographs....

Resolution Of Ebsd 41 Lateral Resolution

In order to use EBSD for the study of nano-crystalline materials we must understand the spatial resolution of the measurement. The spatial resolution of EBSD is strongly influenced by the atomic number of the material to be studied, the accelerating voltage of the SEM, the focused probe size and the sample tilt. For EBSD to be useful for nano-crystalline materials, each of these parameters must be carefully set to achieve high spatial resolution required for the study of nano-crystalline...

Electronsolid Interactions 31 Electron Scattering in Solid

As the electrons penetrate the solid materials, such as the electron beam resist, the interaction can be characterized by scatterings. There are two kinds of scatterings during the electron-solid interaction small angle scattering forward scattering , which tends to broaden the initial beam diameter, and the large angle scattering backscattering , which causes the proximity effect 13 , where the dose that a pattern feature receives is affected by electrons scattering from other nearby features....

Atom Probe Tomography And Nanotechnology

A general view of nanotechnology encompasses the design and fabrication of materials whose properties are controlled or influenced by features on the nanometer scale. Although nanotechnology often refers to semiconductors and other novel devices, the properties of many conventional materials and alloys are also controlled by features on the nanometer scale. In order to develop the full potential of these types of materials and understand their properties, their nanostructures must be...