Sources Auger electron spectroscopy

Scanning Auger Electron Spectroscopy (SAM) and SIMS (in microprobe or microscope modes). SAM is the most widespread technique, but generally is considered to be of lesser sensitivity than SIMS, at least for spatial resolutions (defined by primary beam diameter d) of approximately 0.1 im. However, with a field emission electron source, SAM can achieve sensitivities tanging from 0.3% at. to 3% at. for Pranging from 1000 A to 300 A, respectively, which is competitive with the best ion microprobes. Even with competitive sensitivity, though, SAM can be very problematic for insulators and electron-sensitive materials. 

Auger electron spectroscopy (29) is a type of electron spectroscopy that is used for determining solid surface elemental and electronic composition. An experiment is conducted by bombarding a solid surface with an electron beam of energy ranging from 1 keV to 10 keV. Alternatively, an x-ray source can be used. The Auger electrons, emitted from an atom by means of a radiationless transition, are... 

X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) are the two main techniques based on electron spectroscopy. In XPS, a source of photons in the X-ray energy range is used to irradiate the sample. 

Secondary ion mass spectrometry (SIMS) is a relatively new technique for surface chemical analysis compared with Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). SIMS examines the mass of ions, instead of energy of electrons, escaped from a solid surface to obtain information on surface chemistry. The term secondary ion is used to distinguish primary ion that is the energy source for knocking out ions from a solid surface. The advantages of SIMS over electron spectroscopy are ... 

Fig. 1.5. Experimental setup of the high-frequency laser vaporization cluster ion source driven by a 100-Hz Nd Yag laser for the production of ion clusters, ion optics with a quadrupole deflector, and quadrupole mass Alter for size-selection and deposition the analysis chamber with a mass spectrometer for thermal desorption spectroscopy (TDS), a Fourier transform infrared spectrometer, a spherical electron energy analyzer for Auger electron spectroscopy (AES) for in situ characterization of the clusters [73]...

Surface analysis (AES/XPS) Electron spectroscopy for elemental analysis of surfaces, sensitive to as low as two atomic layers. Physical electronics model PHI-570 Auger Electron Spectroscopy/X-ray Photoelectron Spectroscopy System is a double pass cylindrical mirror energy analyzer with dual anode (Mg/Al) X-ray source and has a rapid sample introduction probe. It can detect elements at the first five to ten atomic layers of sample and detect all elements except H and He. 

The studies of Ertl and associates employed a surface consisting of the (0001) face of a ruthenium single crystal. Copper was deposited on the ruthenium surface by exposing the surface to a flux of copper atoms obtained by evaporation of a copper source. From low energy electron diffraction, Auger electron spectroscopy, thermal desorption, and work function measurements (18) Ertl and associates concluded that copper deposits on the ruthenium surface at 540 K in the form of a two-dimensional overlayer to coverages of 50 to 60%, beyond which there is a transition to a three-dimensional growth phase. 

Figure 1. Modes of operation of the cerl field emission source SEM with environmental cell. Key top, scanning electron microscopy, Auger electron spectroscopy, and argon ion etching and bottom, gas reaction cell configuration.

X-ray excited Auger Electron Spectroscopy (XAES) is limited by the flux density of the X-ray source, but conveniently accompanies the photoelectron emission spectrum produced in an X-ray Photoelectron Spectrometer. XAES was used by Desimoni and co-workers [54,55],... 

A number of techniques are available to interrogate material surfaces. The development of instrumentation suitable for this type of examination has occured relatively recently, in the last quarter of a century or so. Some of these methods, however, are simply not suitable for polymer analysis, (for example. Auger electron spectroscopy (AES), where the electron beam used as an excitation source is too energetic to avoid damage to organic materials) and all of them have limitations in terms of the information they can provide. By combining techniques which give complementary information one can obtain a detailed description of a polymeric interface. 

The preparation chamber, number I in Figs. 1.2 and 1.3, is equipped with two electron beam evaporators and an effusion cell. A four-pocket mini electron beam evaporator serves for deposition of metals from rods and crucibles from each pocket separately, as well as for codeposition of different combinations of the evaporants. A single-pocket e-beam source is used for deposition of the Mossbauer isotope Fe. An effusion cell Is available for evaporation of rare-earth metals. A precise calibration of the deposition rate with a thickness reproducibility of I A is done by a quartz-balance monitor. The deposited structures can be characterized by low-energy electron diffraction (LEED) and Auger electron spectroscopy (AES). In this chamber, the samples can be cooled down to about 90 K and heated up to 2300 K by a multifunctional manipulator. 

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