Comb capacitor structures for measurement of post-processed layers

We present a simple comb capacitive measurement structure to monitor the properties of post-processed layers. These measurement structures are easily fabricated in a single step in the last metallization layer of a standard IC process, while the post-processed layer in this article is formed over these comb structures by spray coating. The capacitive coupling of the structure on the substrate is modeled based on the electric field distribution around the structure. The change in composition of this post-processed layer is analyzed in terms of measured capacitance values.