Observation of Au[sbnd]Cu alloying by grazing-incidence X-ray fluorescence

Abstract

Alloying between AuCu binary thin layers was observed by grazing-incidence X-ray fluorescence (GI-XRF) technique using a benchtop total-reflection XRF instrument with a Mo-Kα-excited X-ray beam. The as-deposited sample comprising Au and Cu layers deposited on a glass substrate and a corresponding sample heated at 300 °C for 1 h were analyzed by GI-XRF. The angle-dependent GI-XRF profile of the heated sample differed from that of the as-deposited sample. Theoretical calculations of the GI-XRF profiles of the as-deposited and heated samples suggested that alloying occurred at the low temperature of 300 °C. The same samples were further independently investigated using other non-destructive X-ray methods, including X-ray diffraction (XRD), X-ray reflectometry (XRR), and conventional X-ray fluorescence (XRF). The results obtained by the XRD, XRR, and XRF analyses were in good agreement with the GI-XRF results.