Structural Features of Nano-Scale Damascene Copper Lines after Annealing in Wide Temperature Range

Grain structure and texture evolved in damascene nano-scale copper lines after annealing in a wide temperature interval of 200oC-500oC were analyzed. Electron backscatter diffraction (EBSD) technique was used for rigorous investigation of the overburden layer, upper and bottom parts of the lines. In all cases, the microstructures were found to stabilize after achieving the same level of total grain-boundary area per unit volume. The grain growth behavior was supposed to be governed by the pinning effect of second-phase particles entrapped during the electrodeposition process.