Texture Investigation in Cu Damascene Interconnects during Annealing

Textural changes of Cu interconnects having a different line width were investigated after annealing. Texture was measured by XRD (x-ray diffraction) at different depth of the interconnect line and on the surface of interconnects using EBSD (electron backscattered diffraction) techniques. To analyze the relationship between the stress distribution and textural evolution observed in the different samples, the stresses were calculated for the different line width at 200°C using FEM (finite element modeling) along the width and depth of the line. In this investigation, it was found that the inhomogeneity of stress distribution in Cu interconnects is an important factor necessary for understanding textural transformation during annealing. Textural evolution in damascene interconnects lines during annealing is discussed, based on the state of stress in Cu electrodeposits.