DETERMINATION OF INTERFACIAL ROUGHNESS CORRELATION IN W/C MULTILAYER FILMS - COMPARISON USING SOFT AND HARD X-RAY-DIFFRACTION

Interfacial roughness correlation in W/C multilayer films with periods of 23, 30, and 37 angstrom is examined with x-ray diffraction using lambda in the 10-13 angstrom range and lambda = 1.54 angstrom. Transverse scans through multilayer Bragg reflections are analyzed to determine the magnitude and lateral correlation length of the component of interfacial roughness that is perfectly correlated through the multilayer stack. The results are independent of wavelength, even though hard x rays sample much more deeply into the film, indicating that interfacial roughness is not changing through these films.