— For 65nm and below devices, even after optical proximity correction (OPC), the gate may still be non-rectangular. There are several limited works on the device and circuit characterizations for the post-OPC non-ideal-shape wafer images, with significant impacts on timing and power. Most of them, however, are based on the equivalent gate length models, which are different for timing and leakage, and thus hard to use for coherent circuit simulations. In this paper, we propose a unified post-litho device characterization model and circuit simulation for timing and power. To our best knowledge, this is the most accurate methodology for post-litho analysis, including timing, leakage and transient simulation. Based on this method, the parameter extraction is also included in the model which was omitted by previous works. A post-litho model card is proposed for circuit simulation to combine these two techniques. Our experimental results validate the new model.
Sean X. Shi, Peng Yu, David Z. Pan