Quantification of Au deposited on Ni: XPS peak shape analysis compared to RES

We investigated the degree of quantitative agreement between XPS peak shape analysis and RES with respect to the average thickness of Au layers deposi ted on Ni. Gold layers in the range of 5-100 Angstrom were prepared on five substrate samples. By peak shape analysis of the An 4d XPS peaks, the stru cture and amount of an was determined. Likewise, by measuring with RES on 3 -5 regions of each sample the An thickness in these regions was determined. Comparing the results, we determined the deviation between XPS and the mea n value of the RES thickness. For three of the samples the deviations were 6-7%. For the remaining two samples the agreement was worse. However, as sh own by the scatter in the RES results for each sample, the disagreement was due to a non-uniform Au layer and not to the techniques. It is found that the absolute accuracy of the XPS peak shape analysis technique is similar t o 7% for depths of less than or equal to 7-8 IMFP. (C) 1999 John Wiley & So ns, Ltd.