Energy Dispersive X-Ray Reflectivity (EDXRR) - X-ray reflectivity is a
technique for measuring thin film roughness and layer thickness
non-destructively. The technique is highly sensitive and can measure RMS
surface roughness as low as 0.1 nm. By using energy dispersive detection and a
broad-band x-ray source, the reflectivity spectrum is obtained more rapidly than
by conventional angle scanning means. Full XRR spectra have been obtained in
only 20 s from metal films on oxidized Si. This rapid acquisition makes it
possible to monitor the evolution of the surface during growth or sputter
etching, as well as to look at reactions at buried interfaces during annealing.
The measurements in figure 4 show the kinetics of the formation of a Al-Cr
intermetallic during annealing of a layered Al/Cr/SiO2 structure.
Consumption of the Cr layer can lead to deadhesion of the film. Note that the
measurements were obtained from one sample in real time; similar results using
ex situ techniques would require multiple samples.