No abstract

Grain growth in polycrystalline films is controlled by the energetics of the surface, interface and grain boundaries as well as strain energy. The unique character of damascene lines fabricated from electroplated Cu films introduces the additional considerations of bath chemistry and geometric constraints. The moderate stacking fault energy of Cu allows for the development of a substantial twin fraction for certain growth conditions. This paper discusses in-situ observation of grain growth in Cu films and lines under various processing conditions. It is shown that for thicker films and for structures constrained within damascene trenches the energetics of twin boundary formation play a large role in texture development of these structures.