Damascene copper is rapidly replacing aluminum as the interconnect material of choice in silicon technology. The change is driven by the lower electrical resistivity of copper, which decreases power consumption and permits increased central processor unit (CPU) clocking speeds. Electroplating is the preferred deposition method because it permits filling of high-aspect ratio features without seams or voids through the process of superconformal deposition, also called superfill.” This process only occurs when particular combinations of chemical additives are included in the electrolyte . Two crucial mechanisms by which the additives enable super-fill to occur are (a) accelerator behavior increasing the copper deposition rate as a function of coverage and (b) conservation of accelerator coverage with increasing/decreasing arc length . The model presented here utilizes the level set method (LSM) to track the position of the copper/electrolyte interface as the features are filling.
Journal: TechConnect Briefs
Volume: 1, Technical Proceedings of the 2002 International Conference on Modeling and Simulation of Microsystems
Published: April 22, 2002
Pages: 422 - 425
Industry sector: Sensors, MEMS, Electronics
Topics: Modeling & Simulation of Microsystems