Simulation of Cu pumping during TSV fabrication

Abstract

Using Finite element methods, a model to predict the Cu pumping in Through Silicon Vias (TSV) is built. The processes which a TSV undergoes after Cu electroplating are considered and the model is built in such a way that after each process sequence, the stress and strain data are transferred into the following sequence and used as input conditions. The stress and Cu pumping at the end of the simulations are extracted and compared with experimental results. This allows virtual studies and predictions of Cu pumping for different TSV geometries and the possible effects of Back-end of line (BEOL) layers.