Effects of Impurity Elements on Isothermal Grain Growth of Electroplated Copper

Abstract

The grain growth of electroplated copper films implanted with individual impurity elements were studied with elements implanted separately. Sheet resistance evolution, focus ion beam imaging, and X-ray diffraction were used to characterize the grain growth along time at various annealing temperatures. While the incorporation of oxygen, sulfur, and chlorine impedes the grain growth, the oxygen has the weakest impact and chlorine has the strongest. Fully transformed films with coarse grains were obtained at temperatures up to 400 C. The presence of carbon resulted in a nucleation limited grain growth and the full transformation was not achieved until at 700 C. On the other hand, the presence of chlorine enhanced a preference of grain growth in [111] orientation. This study aims to provide a new perspective of improving grain structures of copper with engineered chemical additives.