In relation with the formation of voids or cracks in Cu interconnections for integrated circuits, we are interested to measure the stresses resulting from the thermal cycles during the process. X ray diffraction measurements have been performed on periodic arrays of Cu lines fabricated with the damascene process. The parameter investigated was the linewidth ranging from 0.34 mum to 2.59 mum. Textures analysis has showed that the grains grow from the bottom of the lines when the linewidth is greater than the thickness and from the sidewall in the opposite case. The knowledge of these grains orientations has allowed an evaluation of the macroscopic elastic tensors of the lines taking into account the strong anisotropy of Cu. Starting from crystallographic planes strain measurements we have then determine the Cu state of stress. We deal with a triaxial tensile state which is quasi hydrostatic when linewidth and thickness are the same. Its level increases with decreasing linewidth.