Electron backscatter diffraction analysis of electrodeposited nano-scale copper wires

• Texture distribution is essentially inhomogeneous in the line depth direction.
• The material contains significant proportions of low-angle and twin boundaries.
• The material is the least recrystallized in the bottom part of the lines.

The high-resolution electron backscatter diffraction technique was applied to study grain-size, misorientation distribution and texture, which affect resistivity substantially, in electrodeposited and subsequently annealed nano-scale (80 nm width) copper wires. Particular emphasis was given to the examination of the variation of the microstructural parameters and texture in the trench thickness direction. The bottom part of the wires was shown to be characterized by the largest proportion of low-angle boundaries and the lowest fraction of annealing twins. The crystallographic texture of the wires was also demonstrated to significantly change in thickness direction. Depending on the trench height, the close packed {111} plane was shown to align either with the side walls or the bottom surface.