Development of the Grain Size Evaluating Proeess in Very Narrow Cu Interconnects

摘要

Grain size distributions of less than 100 nm wide Cu interconnects made by DC electroplating have been evaluated by the X-ray diffraction method. The mean grain size of the annealed Cu interconnects was found to be expressed as a linear function of the product of the overburden Cu film thickness times the ratio of the interconnect trench width to depth. This linear relationship describes how to use the interconnect parameters like the thickness of the overburden Cu film and the depth and width of the trench to evaluate the mean grain size in narrow annealed Cu interconnects up to 50 nm wide.