The Impact of Linewidth and Line Density on the Texture of Electroplated Cu in Damascene-Fabricated Lines

Effects of linewidth and line area density on the texture of chemical mechanical polished Damascene-fabricated isolation trenches are studied. Texture evaluated by electron backscatter diffraction was found to be impacted by both. For linewidths of 1.4 and , there was a strong improvement in (111) fiber texture as linewidth increased. For line area densities of 40 and 57%, there was a less strong though significant decrease of the (111) texture as the line area density increased. We suggest a reason for these texture variations based on the influence of the geometrical constraints during deposition. The chemical mechanical polishing removal rate showed a difference of 30% between electroplated with a poor texture and one with a strong texture, implying that localized texture variations can lead to localized nonuniformity during chemical mechanical polishing. (c)1999 The Electrochemical Society