AES ANALYSIS OF BARIUM FLUORIDE THIN-FILMS

AES analysis of thin films of metal fluorides is a difficult problem d ue to charging and decomposition of such films under electron bombardm ent. We have developed a simple algorithm for a reliable quantitative AES analysis of metal fluoride thin films (BaF2 in our work). The rela tive AES sensitivity factors for barium and fluorine were determined f rom BaF2 single-crystal samples. We have investigated the dependence o f 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 anal ysis of metal fluoride thin films.