ASTM E1016-07(R2020) pdf free download

ASTM E1016-07(R2020) pdf free download.Standard Guide for Literature Describing Properties of Electrostatic Electron Spectrometers
7. Literature
7.1 Electrostatic Analyzers—Spectrometers commonly used on modern AES and XPS spectrometer instruments generally employ electrostatic deflection analyzers. Auger electron spec- trometers often use cylindrical mirror analyzer (CMA) designs, although concentric hemispherical analyzers (CHA) (also known as spherical deflection (or sector) analyzers) are also used. The CHA design is the most common analyzer employed on modern XPS instruments, although double-pass CMA designs were also employed on earlier XPS instruments. Retarding field analyzers (RFA) have historical interest in early AES work, but are now commonly used on low energy electron diffraction apparatus. 7.1.1 Electrostatic Deflection Analyzers—A review of the general properties of deflection analyzers may be found in review articles (16, 17). More detailed reviews are also available where, in addition to the CMA and CHA designs, plane mirror, spherical mirror, cylindrical sector, and toroidal deflection analyzers are treated (18-20). As the width oftypical Auger spectral features are several electron volts, the use of a CMA design in conventional AES has sufficed for routine analysis, particularly for small area analysis where a compro- mise between signal-to-noise and energy resolution is impor- tant. These are commonly used at a resolution defined by the full-width at half-maximum of the spectrometer energy resolution, ∆E, divided by the electron energy, E, of 0.25 to 0.6 %. The ability to incorporate an electron source concentric with the CMA axis has been extensively exploited in scanning- electron microscope instruments to give Auger data as a function of beam position (that is, images). However, analysis of the Auger spectra from some compounds and surface morphologies may be enhanced by the use of a CHA design which can provide better energy resolution (but a lower transmission) and superior angular resolution. The relationship between the pass energy of various spectrometer designs and the potential between their electrodes is described in detail (16). 7.1.2 Retarding Field Analyzers—The use of a retarding field analyzer (RFA), consisting of concentric, spherical-sector grids, is currently used most commonly on electron diffraction instruments where the angular distribution of the detected electrons is examined. See also a brief review of RFA designs (16) and a substantial report on resolution and sensitivity issues (21).7.2 Apertures—The effects of the spectrometer entrance and exit slits and apertures, their associated fringing fields, as well as the effect of the divergence of the incident electron trajec- tories on analyzer performance, particularly energy resolution, have also been reviewed (16-20). A detailed examination ofthe effects of unwanted internal scattering in CHA and CMA electron spectrometers has been reported in the literature (22-24). 7.3 Lens Systems—Input lens systems are frequently em- ployed in CHA (and cylindrical sector) designs to vary the surface analysis area (25) and to permit a convenient location of the CHA so as to allow access of complementary surface characterization techniques to the sample (26). The electro- static lens design often consists ofa coaxial series ofelectrodes that define the analysis area on the sample surface and determines the electron trajectories at the input to the analyzer. The lens system also determines the angular resolution and modifies the transmission characteristics of the spectrometer system (1). Reviews of electrostatic lens systems incorporated in surface analysis instruments have been published (16-20, 27). Lens systems have also been introduced at the exit of analyzers for photoelectron imaging (17, 28-30). Methods to determine the specimen area examined are described in Prac- tice E1217.