Texture development of blanket electroplated copper films

The transition from sputtered Al to electroplated Cu interconnects for future microelectronic devices has led to an interest in understanding the relationships between the microstructure and texture of Cu that might impact electrical performance, similar to what has been done for Al. Electroplated Cu undergoes a recrystallization at room temperature that is related to the presence of organic and inorganic additives in the plating bath. As plated, the Cu grains are small (approx. 0.1 mu m) and equiaxed, but over a period of hours to days, recrystallization results in grains several microns in size. We observe a significant weakening of the strong as-plated (111) texture by x-ray diffraction pole figure measurements and an increase in the level of randomness. We propose that multiple twinning is the leading mechanism for this phenomenon. (C) 2000 American Institute of Physics. [S0021-8979(00)03805-6].