Characterization of a new type of Cr/Ni multilayer structure with AES and TEM

Abstract

A new type of multilayer structure, composed of alternating Cr and Ni thin films with a thickness increasing from 15 to 200 nm in the direction from the surface to the smooth Si substrate and with a total thickness of 1.1 mm, was investigated with Auger sputter depth profiling and transmission electron microscopy (TEM). TEM investigations of a cross-sectioned Cr/Ni multilayer shoowed the fine grained column structure of individual thin films and the sharp interfaces between them. The usefulness of the new Cr/Ni multilayer structure in fundamental investigations is demonstrated with AES sputter depth profiling of the samples, using different ion sputtering parameters. Applying the sample rotation technique during AES depth profiling, a depth profile of an as-deposited Cr/Ni sample with sharp interfaces was obtained through the entire multilayer of thickness of 1.1 mm; the depth resolution was constant for sputtered depths between 40 and 100 nm and larger than 200 nm. The interface broadening in AES depth profiles of as-deposited Cr/Ni multilayers and of those annealed at 400°C was measured and the diffusion parameters of Cr and Ni were calculated.