AES ANALYSIS OF BARIUM FLUORIDE THIN-FILMS

AES analysis of thin films of metal fluorides is a difficult problem due to charging and decomposition of such films under electron bombardment. We have developed a simple algorithm for a reliable quantitative AES analysis of metal fluoride thin films (BaF2 in our work). The relative AES sensitivity factors for barium and fluorine were determined from BaF2 single-crystal samples. We have investigated the dependence of composition and stability of barium fluoride films on the substrate temperature during film growth. We found that the instability of BaF2 films grown on GaAs substrates at high temperatures (> 525-degrees-C) is due to a loss of fluorine. Our results show that, under the optimal electron exposure conditions, AES can be used for a quantitative analysis of metal fluoride thin films.