EVALUATION OF XPS-DATA OF OXIDE LAYERS

XPS with variable take-off angle has been applied to the determination of the thickness of thin oxide layers (SiO2 on Si). The information about D/λox gained by such measurements is strongly influenced by surface roughness. This influence can be demonstrated when the parameters R and D/λox are calculated from sets of the experimental results and for each set the corresponding pair of R and D/λox is plotted in a diagram D/λox = f(R). Having the true value of R it is possible to determine D/λox. With the XPS-results of at least three different oxide layers and their ellipsometric thicknesses De one is able to calculate λSi, λox/λSi and the difference ΔD between De and the XPS-thickness D. © 1974.