X-ray residual stress analysis in CVD multilayer systems: Influence of steep gradients on the line profile shape and - symmetry

摘要

Residual stresses in multilayer systems are usually not uniform but occur in form of gradients which are balanced either within the individual layers or between different lay-ers and the substrate. Starting from a formalism which extends the method of X-ray residual stress depth profiling in monolayer thin films to the multilayer case, as-grown and grit-blasted Al_2O_3/TiCN hard coating systems are analyzed with respect to the in-plane residual stress state. For the Al_2O_3-layer on top the blasting process results in a steep residual stress gradient leading to a nonlinear d~h_Ψ- sin~2 Ψ -distribution as well as asymmetric diffraction line profiles, the shape and integral breadth of which vary during strain depth profiling.