TSV front end design, integration, and process development unique cell design and process integration

摘要

An innovative TSV approach that removes the historical limitations of Cu and W filled TSVs, making W TSVs once again attractive. Both films have their own advantages and disadvantages. Cu TSVs has two major advantages, one Cu electroplating has the ability to fill high aspect ratio vias enabling a wider via compared to W, and two Cu resistivity is much lower than W enabling a lower resistance via. The primary advantage that W has over Cu is that the coefficient of thermal expansion (CTE) is much closer to that of silicon. This can enable larger TSVs with higher current carrying capability and reduced reliability/stress risk. The unique and innovative TSV cell design that's presented in this paper includes a central silicon support structure. The unit cell can then be expanded into multi-cell arrays. The approach allows increased via area decreasing the overall via resistance with higher current carrying capability and reduced reliability/stress risk than has previously been available.