Auger electron spectroscopy

Abstract: The available body of information on (a) fluorescence, Auger, and Coster‐Kronig yields, (b) radiative and radiationless transition rates, (c) level widths, (d) x‐ray and Auger line widths, (e) x‐ray and Auger spectra, and (f) Coster‐Kronig energies has been used to generate an internally consistent set of values of atomic radiative and radiationless yields for the K shell (5 ?Z?110) and the L subshells (12 ?Z?110). Values of fluorescence yields ωk, ω1, ω2, ω3, Coster‐Kronig yields F1, F1.2, F1.3, F1.3, F2.3. Auger yields ak, a1, a2, a3, and effective fluorescence yields ν1 and ν2 are presented in tables and graphs. Estimates of uncertainties are given. Updated and expanded graphs of partial and total widths of K, L1, L2, and L3 levels are presented as well as a reference list of papers published since about 1972.

Abstract: A low temperature thermal cleaning method for Si molecular beam epitaxy (MBE) is proposed. This method consists of wet chemical treatment to eliminate carbon contaminants on Si substrates, thin oxide film formation to protect the clean Si surface from contamination during processing before MBE growth, and desorption of the thin oxide film under UHV. The passivative oxide can be removed at temperatures below 800°C. It is confirmed that Si epitaxial growth can take place on substrates cleaned by this method and that high quality Si layers with dislocations of fewer than 100/cm2 and high mobility comparable to good bulk materials are formed. Surface cleanliness, the nature of thin passivative oxide films, and cleaning processes are also studied by using such surface analytic methods as Auger electron spectroscopy, reflection high energy electron diffraction, and x‐ray photoelectron spectroscopy.

Abstract: This paper provides a brief introduction to the theory and practice of low-energy electron diffraction, a tcchnique which is proving useful for investigating the structure of surfaces. Emphasis is given to clean well-defined surfaces which are studied also with Auger electron spectroscopy and under conditions of ultra-high vacuum. Knowledge of surface structure is of fundamental and technological interest, and, although only two-dimensional periodicities in surface regions are obtained directly from diffraction patterns, even this has led to the discovery of unexpected structural arrangements. Recently there has been substantial progress in the understanding of diffracted beam intensities, and procedures are reviewed for extracting surface structures from measured intensities.