Diffusion markers in Al/metal thin-film reactions

Abstract A method was developed to measure the diffusing species in aluminide formation in cases where the reacted layer is laterally nonuniform. Rutherford backscattering spectrometry was used to determine the amount of each metal (atoms/cm 2 ) over the marker at different stages of the annealing sequence. This overlayer measurement gave equivalent results when compared with conventional energy width and marker displacement analysis in suicide formation. By using a tungsten marker diluted with Al, instead of a pure tungsten film, we minimized barrier problems. The marker was sandwiched between coevaporated layers of the compound being studied to reduce interface drag. We found for the growth of TiAl 3 and NiAl 3 that Al is the dominant moving species in agreement with previous results in thin-film (TiAl 3 ) and bulk (NiAl 3 ) measurements.