Investigation into the stress assisted damage of copper surface under single asperity: influence of contact pressures, surfaces stress states and environments

An experiment setup was used to investigate the effects of contact loads, surface stress state and surface environment on dissolution and damage of copper surface. A range of surface stress state was generated with a four-point-bending setup on a well-polished copper sample. Single asperity contact was investigated using the cantilever tip of an Atomic Force Microscope. Controlled tip contact pressures were applied on the copper surface to mechanically stimulate the stressed surface. The experiment was performed in different environments to determine the chemical effects. Volume of material removed during the process was measured to determine material removal rate as a function of contact pressure, surface stress state and environments. It shows, as expected, higher contact pressures accelerate the material removal rates but complicated behaviors of the effects of surface stress and environments were observed. Mechanics governing material removal and their removal to Chemical Mechanical Polishing of copper was discussed

Load Assisted Dissolution AND Damage of Copper Surface under Single Asperity Contact: Influence of Contact Loads and Surface Environment

Copper has become a widely used material in advanced submicron multilevel technologies due to its low resistivity and high electromigration resistance. Copper based devices are manufactured using additive patterning and subsequently undergo chemical mechanical planarization (CMP) to ensure good interconnection. During CMP, material is removed through synergistic combination of chemical reactions and mechanical stimulations. Empirical models such as Preston’s equation are used to explain the material removal rate during CMP but a mechanism based understanding of the synergistic interactions between chemical environment and mechanical loading is still lacking

Load Assisted Dissolution AND Damage of Copper Surface under Single Asperity Contact: Influence of Contact Loads and Surface Environment

Copper has become a widely used material in advanced submicron multilevel technologies due to its low resistivity and high electromigration resistance. Copper based devices are manufactured using additive patterning and subsequently undergo chemical mechanical planarization (CMP) to ensure good interconnection. During CMP, material is removed through synergistic combination of chemical reactions and mechanical stimulations. Empirical models such as Preston’s equation are used to explain the material removal rate during CMP but a mechanism based understanding of the synergistic interactions between chemical environment and mechanical loading is still lacking.</p