AS ISO 19319:2006 pdf download.Surface chemical analysis-Augurelectron spectroscopy and X-ray photoelectron spectroscopy一Determination of lateral resolution,analysis area and sample area viewed by the analyser.
As In optical [3-6] and various forms of electron microscopy (7-9), the achievable lateral resolution is related to the contrast found In a measured image. A discussion of contrast mechanisms, various definitions of Lateral resolution, and image quality is beyond the scope of this report, and the reader is referred to detailed analyses available elsewhere (3-9). It is pointed out, however, that the contrast transfer function is a useful means for describing the contrast in an image as a function of spatial frequency (3-9). At the highest detectable spatial frequency, the contrast approaches zero. The achievable lateral resolution in a particular AES or XPS measurement will therefore depend not only on the instrumental characteristics but on the avadable contrast (e.g., from the signals associated with two neighbouring chemical phases for a particular measurement time).
An overview Is given In this report of certain Instrumental and measured properties that are described in terms of Gaussian functions. This approach is believed to be a useful guide but It should be emphasized that the properties of real instruments and of real measurements can depart from the Gaussian model considered here. In addition, the detectabiility of a feature in AES and XPS measurements depends in part on the measure of lateral resolution of the instrument arid in part on the difference in signal intensities for measurements made on and off the possdle feature and the observation time (through the statistical variations in the signal intensities), The detectability of a feature thus depends on the contrast transfer function for the measurement and the measurement time, The specific results will thus be a function of both instrumental and sample properties. Reliable detection of a feature will also depend on instrumental stability (particularly the stabllity of the incident electron beam current in AES and the X-ray flux in XPS, and the positional stability of the sample stage with respect to the electron or X-ray beam) and the chemical stability of the sample during the time needed for acquisition of AES or XPS data.
An overview Is given In this report of certain Instrumental and measured properties that are described in terms of Gaussian functions. This approach is believed to be a useful guide but It should be emphasized that the properties of real instruments and of real measurements can depart from the Gaussian model considered here. In addition, the detectabiility of a feature in AES and XPS measurements depends in part on the measure of lateral resolution of the instrument arid in part on the difference in signal intensities for measurements made on and off the possdle feature and the observation time (through the statistical variations in the signal intensities), The detectability of a feature thus depends on the contrast transfer function for the measurement and the measurement time, The specific results will thus be a function of both instrumental and sample properties. Reliable detection of a feature will also depend on instrumental stability (particularly the stabllity of the incident electron beam current in AES and the X-ray flux in XPS, and the positional stability of the sample stage with respect to the electron or X-ray beam) and the chemical stability of the sample during the time needed for acquisition of AES or XPS data.
