• Zalesak, Jaroslav
• Mackova, A.
• Keckes, J.
• Burghammer, M.
• Davydok, A.
• Krywka, C.
• Daniel, Rostislav
• Todt, Juraj
• Hlushko, K.

Abstract

The influence of ion irradiation on residual stress and microstructure of thin films is not fully understood. Here, 5 MeV Si2+ ions were used to irradiate a 7 µm thick tungsten film prepared by magnetron sputtering. Cross-sectional X-ray nanodiffraction and electron microscopy analyses revealed a depth-localized relaxation of in-plane compressive residual stresses from toGPa after the irradiation, which is correlated with the calculated displacements per atom within a ~2 µm thick film region. The relaxation can be explained by the irradiation-induced removal of point defects from the crystal lattice, resulting in a reduction of strains of the 3rd order, manifested by a decrease of X-ray diffraction peak broadening, an increase of peak intensities and a decrease of lattice parameter. The results indicate that ion irradiation enables control over the residual stress state at distinct depths in the material.

Topics

• impedance spectroscopy
• microstructure
• x-ray diffraction
• thin film
• electron microscopy
• tungsten
• crystalline lattice
• point defect