X-ray diffraction pole figure evidence for (111) sidewall texture of electroplated Cu in submicron damascene trenches

The crystallographic texture of electroplated Cu in damascene trenches has been examined by x-ray diffraction pole figure analysis. The influence of t wo post-plating treatments on the resulting orientation of (111) planes of the Cu inside the trenches are compared. When the as-deposited small-graine d Cu is allowed to recrystallize at room temperature before chemical mechan ical polishing of the overlying Cu, we observe only a (111) fiber texture o f the Cu inside the trenches. In contrast, when the overlying material is p olished away before recrystallization of the small-grained Cu, pole figures show evidence of sidewall texture of the (111) planes in addition to the ( 111) fiber texture in the as-deposited as well as the annealed state. The p resence or absence of a sidewall texture component in the pole figures offe rs insight into the evolution of the microstructure of damascene Cu. (C) 19 99 American Institute of Physics. [S0003-6951(99)00505-7].