Atomic force microscopy (AFM) is a form of scanning probe microscopy (SPM), where a small probe is scanned across the sample to obtain information on the sample surface. The information gathered by the interaction of the probe with the surface can be as simple as physical topography or other material such as measurements of physical, magnetic, or chemical properties. These data are collected as the probe is scanned in a raster pattern through the sample to form a map of the property measured from the XY position. Thus, the AFM microscope image shows the change in the property measured, for example. height or magnetic domains, over the image area.

The AFM probe tip has a very sharp, often less than 100 in diameter, at the end of a small cantilever beam. The probe is connected to a piezoelectric tube scanner, which scans the probe in a selected area of the surface of the sample. Interatomic forces between the probe tip and the sample surface cause the cantilever to deflect the topography of the sample surface (or other property) changes. A laser light reflected from the back of the cantilever measures the deflection of the cantilever. This information is sent back to a computer, which generates a map of topography and / or other properties of interest. All square as large as about 100 ìm square less than 100 nm can be resumed.

INFORMATION ANALYSIS

Modes of contact AFM – The AFM probe is scanned at a constant force between the probe and the sample surface to obtain a 3D topographical map. When the probe cantilever is deflected by topographic changes, the scanner changes the position of the probe to restore the original cantilever deflection. The location information of the scanner is used to create a topographic image. Lateral resolution of <1 style = “font-weight: bold;”> intermittent contact (tapping mode) AFM – In this mode, the cantilever probe is oscillated or at its resonant frequency. The oscillating probe tip is then scanned at a height where it barely touches or “taps” the surface of the sample. The system monitors the position of the probe and the amplitude of oscillation to obtain information on topographic properties and others. Precise topographic information can be obtained even for very delicate surfaces. Optimum resolution is about 50 Å lateral and <1 style = “font-weight: bold;”> Lateral Force Microscopy – This method of measuring the lateral deviation of the cantilever probe tip is scanned across the sample in contact mode. Changes in lateral bending forces are on the friction between the probe tip and the sample surface.

Detection phase microscopy with the operating system in tapping mode, the cantilever oscillation is damped by the interaction with the sample surface. The phase delay between the signal units and actual cantilever oscillation is monitored. Changes in the phase lag indicate variations in surface properties such as viscoelasticity or mechanical. Image phase, typically collected simultaneously with a topographic image, maps the local changes in physical properties and mechanical properties of the material.

Magnetic Force Microscopy – this image to local variations in the magnetic forces on the sample surface. The tip of the probe is coated with a thin film of ferromagnetic material that reacts to magnetic domains on the surface of the sample. The magnetic forces between the tip and the sample are measured by monitoring the cantilever deflection, while the probe is scanned at a constant height above the surface. A map showing the sample natural forces or applied magnetic domain structure.

Image analysis – Since the images are collected in digital format, a wide range of image manipulation are available for the AFM data. Quantitative topographic information, such as the lateral spacing, step height and the roughness of the surface are readily obtained. Images can be presented as two-dimensional or three-dimensional representations on paper or as digital image files for electronic transfer and publication.

Nanoindentation – A tip of the probe is forced specializes in the sample surface to obtain a measure of the mechanical properties of the material in areas as small as a few nanometers. (See Manual nanoindentation hardness tests.)

TYPICAL APPLICATIONS

* 3-dimensional topography of IC device
* Measures of roughness for the chemical mechanical polishing
* Analysis of the distribution phase microscopic polymer
* Measures of physical and mechanical properties of thin films
* Imaging magnetic domains on digital storage media
* Pictures of the phases of submicron in metals
* Imaging defect in IC failure analysis
* Microscope images of biological samples fragile
* Metrology Stampers compact disk

SAMPLE REQUIREMENTS

No sample preparation is usually necessary. Samples can be taken up in the air or liquid. Sample height is limited to about 1.5 inches. Areas up to 8 inches in diameter can be completely crossed without repositioning. Larger samples may be automatic for imaging in a limited area. Roughness of the surface total image area should not exceed about 6 microns.

source: actually i get this article from my friend’s blog which unfortunately i forget it’s link, but because of someone claim this article to his mine, so i would credit this article to: www.mee-inc.com, thanks for your claiming, it really helpfull to me and my visitor in order to adding our refference

Incoming search terms for the article:

• atomic force microscopy
• imaging magnetic domains on digital storage media

Auger Electron Spectroscopy (AES) provides information on the chemical composition of the outer material that includes a solid surface or interface. The main advantages of AES over other methods of surface analysis are excellent spatial resolution (<1 micron), the sensitivity of the surface (~ 20 aa), and detection of light elements. Detection limits for most elements ranged from approximately 0.01-0.1% a.

AES uses a primary beam of electrons to excite the sample surface. When an inner-shell electron is ejected from an atom of the sample through interaction with a primary electron, an electron from an outer shell fills the vacancy. To compensate for the change of energy from this transition, an Auger electron or X-rays is emitted. For light elements, the probability is greater for the issuance of an Auger electron, which represents the light element sensitivity of this technique.

The energy emitted Auger electron is characteristic of the element from which it was issued. The detection and energy analysis of Auger electrons emitted produces an Auger electron energy spectrum against the relative abundance of electrons. Peaks in the spectrum to identify the elemental composition of the sample surface. In some cases, the chemical state of surface atoms can also be determined by the movement of energy and peak shapes.

Auger electrons have relatively low kinetic energy, which limits their depth of flight. Any Auger electrons emitted from an interaction below the surface lose energy through further reaction dispersion along its path towards the surface. Auger electrons emitted at a depth greater than approximately 2 – 3 nm have sufficient energy to escape to the surface and reach the detector. Thus, the volume of analysis for AES only extend to a depth of about 2 nm. Depth of analysis is not influenced by the energy of the primary energy of electrons.

AES instrumentation may include a filament of tungsten or electronic field emission gun electron beam for the primary. The instruments are equipped with secondary electron imaging (SEM) to facilitate the localization of areas of analysis selected, and photographs of the surface of the sample can be obtained. The sample chamber is maintained at ultra vacuum to minimize the interception of Auger electrons by gas molecules between the sample and the detector. Some tools are special tests for the samples to examine the fracture interfaces that have recently been exposed inside the vacuum chamber. A computer is used for the acquisition, analysis and data visualization AES.

INFORMATION ANALYSIS

Survey Scan – The location of the peaks in the spectrum obtained in AES survey scan identifies the elemental composition of the top 20a of the surface analyzed.

Multiplex Scan – The analysis of high resolution Auger spectrum in the region around a peak feature is used to determine the atomic concentration of the elements identified in the scans and in some cases, information on the chemical.

Quantification – The results of AES analysis can be quantified in the absence of rules through the area under the peaks in the spectrum AES and corrections on the basis of elemental sensitivity factors.

Mapping and Line scans – These imaging techniques that measure the lateral distribution of elements on the surface. The electron beam is scanned across the sample surface, or along a fixed line (scan line) or through a designated area (mapping), while the AES signal is analyzed for specific energy channels. The intensity of the AES signal is a function of relative concentration of the element (s) corresponding to the selected channel energy (s). Spatial resolution is approximately 0.3 microns.

Depth profile – the material is removed from the surface by sputtering with an ion beam energy in conjunction with subsequent analysis of AES. This process measures the elemental distribution as a function of depth in the sample. Depth resolution of <100 A is possible.

TYPICAL APPLICATIONS

The identification of microscopic particles
Passive oxide film thickness
Contamination on chips
Quantification of film surface of the light elements
Mapping the spatial distribution of surface constituents

source: actually i get this article from my friend’s blog which unfortunately i forget it’s link, but because of someone claim this article to his mine, so i would credit this article to: www.mee-inc.com, thanks for your claiming, it really helpfull to me and my visitor in order to adding our refference

Incoming search terms for the article:

• auger electron spectroscopy
• Auger Scan
• auger electron spectroscopy instrumentation
• techniques and instrumentation of electron spectroscopy
• electronic spectroscopy
• auger electron spectroscopy line scan
• instrumentation auger spettroscopy
• aes atomic concentration
• instrumentation of auger spectroscopy
• multiplex scan auger
• depth of analysis in AES
• auger spectroscopy
• auger scand demo
• auger multiplex
• Auger Electron Spectroscopy concentlation
• aes primary electron energy
• AES elemental mapping
• why auger is for light element?

DESCRIPTION OF TECHNIQUE

Energy Dispersive X-Ray Spectroscopy (EDS or EDX) is a technique used in conjunction with chemical microanalysis by scanning electron microscopy (SEM). (See Manual SEM.) EDS technique detects X-rays emitted from the sample during bombardment by an electron beam to characterize the elemental composition of the volume analyzed. Functions or steps as small as 1 micron or less can be analyzed.

When the sample is bombarded by the electron beam SEM, the electrons are ejected from atoms comprising the sample surface. The resulting electron vacancies are filled by electrons from a higher state, and an x-ray is emitted to balance the energy difference between the states the two electrons’. The X-ray energy is characteristic of the element from which it was issued.

EDS x-ray detector measures the relative abundance of X-rays against their energy. The detector is typically a lithium-drifted silicon solid-state device. When an incident x-ray hits the detector, which creates a pulse of charge that is proportional to the energy of x-ray. The pulse charge is converted to a pulse voltage (which is proportional to the energy xray) by a charge sensitive preamplifier. The signal is then sent to a multichannel analyzer where the pulses are sorted by the tension. The energy, as determined by measuring the voltage per incident x-ray is sent to a computer for display and further data evaluation. The spectrum of x-ray energy versus counts is evaluated to determine the elemental composition of the sample volume.

INFORMATION ANALYSIS

Qualitative analysis – The sample values from x-ray energy spectrum EDS are compared with known characteristic x-ray energy values to determine the presence of an element in the sample. Elements with atomic numbers ranging from beryllium to uranium can be detected. The lower limits of detection range from about 0.1 % to one atom of a few percentage points, depending on the element and the sample matrix.

The quantitative analysis – quantitative results can be obtained from the count on the x-ray energy levels characteristic for components of the sample. Semi-quantitative results are readily available, without using the standard mathematical corrections based on the analysis parameters and the composition of the sample. The accuracy of the standardless analysis depends on the composition of the sample. Greater accuracy is obtained using known standard structure and composition similar to that of the unknown sample.

Elemental Mapping – Characteristic x-ray intensity is measured relative to the lateral position on the sample. Variations in intensity of x-ray, in any characteristic value indicates the relative concentration of energy for the item applicable throughout the area. One or more maps are recorded simultaneously with intensity of brightness as a function of local concentration on the item (s) present. About 1 ìm lateral resolution is possible.

Line Profile Analysis – The SEM electron beam is scanned along a line through the pre-selected sample, while the X-rays are collected for the discrete locations along the line. Analysis of x-ray energy spectrum at each position provides plots of relative concentration for each element for primary position along the line.

TYPICAL APPLICATIONS

* Analysis of foreign materials
* Evaluation of corrosion
* Analysis of the composition of coating
* The rapid identification of the material alloy
* Analysis of material small items
* Phase identification and distribution

SAMPLE REQUIREMENTS

Samples up to 8 inches (200 mm) in diameter, can be easily analyzed in SEM. Larger samples, up to about 12 inches (300 mm) in diameter, can be loaded with the stage movement limited. The maximum height of the sample of about 2 inches (50 mm) can be accepted. The samples should also be compatible with a moderate vacuum environment (pressure of 2 Torr or less)

source: actually i get this article from my friend’s blog which unfortunately i forget it’s link, but because of someone claim this article to his mine, so i would credit this article to: www.mee-inc.com, thanks for your claiming, it really helpfull to me and my visitor in order to adding our refference

Incoming search terms for the article:

• edax principle
• edx spectroscopy
• EDX principle
• edx detection limit
• eds detection limit
• Energy Dispersive Spectroscopy
• Principle of EDX
• principles of EDX
• the detection limit of EDX
• detection limit of edx
• detection limit EDX
• principle of edax
• principles of edx analysis
• eds line analysis
• SEM EDS detection limits
• eds detection limits
• detection limit EDS
• what atomic weight percent of Beryllium can EDS detect