Self-annealing characterization of electroplated copper films

Self-annealing of electro-chemically deposited copper films is described and studied, with a focus on the effect of process parameters like concentration of the organic additives, current density or thickness of plated copper. Sheet resistance and stress have been monitored and a non-correlated behavior has been observed for these two film characteristics, indicating that other phenomena than the grain growth typically associated with the room temperature recrystallization are likely to be involved. Diffusion/desorption of carbon containing molecules incorporated in the copper film from the bath additives could be a mechanism for stress release.