ANOMALOUS-DISPERSION X-RAY REFLECTOMETRY FOR MODEL-INDEPENDENT DETERMINATION OF AL C MULTILAYER STRUCTURES/

Electron density profiles across the 90-270 Angstrom depth of Al/C mul tilayers on Ge substrates are determined from anomalous-dispersion X-r ay specular reflectivity data collected at the Ge K edge and away from it. Refractive index parameters for Ge are determined by fits of refl ectivity profiles observed from a Ge surface without the Al/C film at the two photon energies and used in the calculation of electron densit ies for single and triple Al/C bilayers deposited on Ge substrates. Th e layer structures are clearly resolved and the Al/C interfaces are fo und to be considerably broader than expected.