Determination of Interdiffusion Coefficient in Nanolayered Structures by Auger Electron Spectroscopical Sputter Depth Profiling

Abstract

A general method was developed for determination of interdiffusion coefficient in nanolayered structures by Auger electron spectroscopical (AES) sputter depth profiling. The procedures of this method are as follows: (1) the concentration depth profile of annealed sample is calculated from its as-grown layered structure by adopting a suitable diffusion model; (2) this diffusion concentration depth profile is convoluted with a resolution function provided by the mixing-roughness-information depth (MRI)-model and as a result a calculated AES depth profile is obtained; (3) the interdiffusion coefficient is determined by fitting the calculated AES depth profile to the measured one. As an example, the interdiffusion coefficient parameters, the pre-exponential factor and the activation energy, were determined as 4.7×10-18 m2/s and 0.76 eV, respectively, for a GexSi1-x/Si multilayered nanostructure with Ge-Si alloyed layers of 2.2, 4.3 and 2.2 nm thickness in Si matrix.