| Copper electrodeposition is the process whereby solid copper is deposited onto a surface immersed in a chemical solution containing copper ions and various additives. This technique is widely used to fill on-chip interconnects and vias in computer processors. Modeling and simulation have been demonstrated to be indispensable tools for gaining insight into complex and sometimes delicate mechanisms. In addition, simulations have been used to guide the direction of future experimental approaches.;In this work, we have developed a general numerical strategy for simulating electrochemical systems on irregular domains with moving boundaries. This involves solving the governing partial differential equations with algebraic constraints in the bulk electrolyte which are stiffly coupled to an active surface where chemical reactions and other physics occur. Our method makes only a few assumptions about the active surface, namely that it is driven by the bulk chemical species concentrations and applied potential and that it produces a flux of each species back into solution. Otherwise, the details of the surface model are of little consequence. The particular application we study here is copper electrodeposition as applied to filling trench/via interconnects in computer processors. |
