Diffusion in thin bilayer films during rapid thermal annealing

Abstract

The knowledge of pre‐exponential factors and activation energies for low temperatures and short annealing times in nanoscaled systems is important for the downscaling of thermal processes. Here, the diffusion coefficients in aluminum–nickel, aluminum–titanium, titanium–silicon, and aluminum–copper bilayers were determined using rapid thermal annealing. The annealing time was set to 500 s and the investigated bilayer thin film thicknesses were 2 µm. The temperatures ranged from 389 to 613 K depending on the bilayer system. For the various material combinations, the diffusion coefficients were determined by elemental depth profiling and compared to literature values. For the aluminum–copper system, a good agreement with literature and a single set of values was found, whereas for aluminum–nickel, aluminum–titanium, and titanium–silicon two or more sets of values were observed.

X-ray reflectivity measurement of interdiffusion in metallic multilayers during rapid heating

“…If we assume that this is the case, and that the activation energy for grain boundary diffusion is about half that for lattice diffusion [based on an average value for face-centered-cubic metals (Brown (1980)], we arrive at a value of around 100 AE 25 kJ mol À1 . This is consistent with recent measurements (at temperatures similar to ours) by Grieseler and co-workers who reported E a = 120 kJ mol À1 and also assumed a grain boundary diffusion mechanism (Grieseler et al, 2014). Another point of comparison is an activation energy for solid-state interdiffusion of 77 AE 1 kJ mol À1 calculated by Fritz and co-workers based on the ignition threshold for self-propagating reactions in Al/Ni-V multilayers very similar to those considered here (Fritz et al, 2013).…”

Tribological and Mechanical Performance of Ti2AlC and Ti3AlC2 Thin Films

“…The formation of two different MAX phases from the same multilayer system can be attributed to diffusion processes in short diffusion paths during rapid annealing. [ 36 ] This is a remarkable result since both started with the same initial stoichiometry after deposition.…”