Texture development of blanket electroplated copper films

The transition from sputtered Al to electroplated Cu interconnects for futu re microelectronic devices has led to an interest in understanding the rela tionships between the microstructure and texture of Cu that might impact el ectrical performance, similar to what has been done for Al. Electroplated C u 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 s ize. We observe a significant weakening of the strong as-plated (111) textu re by x-ray diffraction pole figure measurements and an increase in the lev el of randomness. We propose that multiple twinning is the leading mechanis m for this phenomenon. (C) 2000 American Institute of Physics. [S0021-8979( 00)03805-6].