Auger electron spectroscopy failure analysis

Laser ionization mass spectrometry or laser microprobing (LIMS) is a microanalyt-ical technique used to rapidly characterize the elemental and, sometimes, molecular composition of materials. It is based on the ability of short high-power laser pulses (-10 ns) to produce ions from solids. The ions formed in these brief pulses are analyzed using a time-of-flight mass spectrometer. The quasi-simultaneous collection of all ion masses allows the survey analysis of unknown materials. The main applications of LIMS are in failure analysis, where chemical differences between a contaminated sample and a control need to be rapidly assessed. The ability to focus the laser beam to a diameter of approximately 1 mm permits the application of this technique to the characterization of small features, for example, in integrated circuits. The LIMS detection limits for many elements are close to 10 at/cm, which makes this technique considerably more sensitive than other survey microan-alytical techniques, such as Auger Electron Spectroscopy (AES) or Electron Probe Microanalysis (EPMA). Additionally, LIMS can be used to analyze insulating sam-... 

Surface analysis has made enormous contributions to the field of adhesion science. It enabled investigators to probe fundamental aspects of adhesion such as the composition of anodic oxides on metals, the surface composition of polymers that have been pretreated by etching, the nature of reactions occurring at the interface between a primer and a substrate or between a primer and an adhesive, and the orientation of molecules adsorbed onto substrates. Surface analysis has also enabled adhesion scientists to determine the mechanisms responsible for failure of adhesive bonds, especially after exposure to aggressive environments. The objective of this chapter is to review the principals of surface analysis techniques including attenuated total reflection (ATR) and reflection-absorption (RAIR) infrared spectroscopy. X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and secondary ion mass spectrometry (SIMS) and to present examples of the application of each technique to important problems in adhesion science. 

The principle of Auger electron spectroscopy (AES) is illustrated schematically in Figure 7. Here, a primary beam of electrons incident on a solid results in the emission of secondary (or Auger) electrons from the top 5 nm of the sample. The energy of the Auger electrons is characteristic of elements contained in the outer surface. Both elemental identification and atomic concentrations can be obtained from AES. The AES technique is not widely used in post-failure analysis of adhesively bonded... 

Surface-sensitive techniques for use in the study of adhesive bonding are discussed, including X-ray photoelectron spectroscopy and auger electron spectroscopy/scanning auger microscopy. Data analysis is considered, with reference to quantification, chemical-state information, depth-distribution information and surface-behaviour diagrams. Applications to adhesive bonding are described, particularly failure analysis, hydration of phosphoric acid-anodised aluminium and adsorption of hydration inhibitors. 100 refs. 

Electrocatalytic reactions occur on catalyst surfaces. The catalyst surface structure and chemically bonded or physically absorbed substances on the catalyst surface exert strong influences on catalyst activity and efficiency. X-ray photoelectron spectroscopy (XPS) (also known as electron spectroscopy for chemical analysis (ESCA), auger emission spectroscopy (AES), or auger analysis) is a failure analysis technique used to identify elements present on the surface of the sample. For instance, this can be used to identify Pt and carbon surface chemical species that may present histories of chemical reactions or contamination in the catalyst layer. AES and XPS can also provide depth profiles of element analysis. Wang et al. [41] studied XPS spectra of carbon and Pt before and after fuel cell operation. They observed a significant increase in O Is peak value for each oxidized carbon support, the result of a higher surface oxide content in the support surface due to electrochemical oxidation. However, sample preparation in AES and XPS analysis is critical because these methods are very sensitive to a trace amount of contaminants on sample surfaces, and detect as little as 2-10 atoms on the sample surface. 

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