Study of the effect of non-planarity and defects on the geometrical accuracy of semiconductor surface structures using a CA_TCAD system

As the integrated circuits (ICs) are pushed deeper into the submicrometer region, the presence of non-planarity and defects are becoming major yield detractors. In this work, we have studied these effects using a two-dimensional technology computer-aided design (TCAD) system based on cellular automata (CAs), which we have named CA_TCAD. It comprises a photolithography etching and a deposition simulator. The photolithography etching simulator has been tested, verified, and calibrated with a series of experiments with periodic and isolated lines on negative resist-coated Si wafers, using a stepper and a deep UV source at 248 nm. The deposition simulator can provide scanning electron microscopy (SEM)-like cross-sectional views, and the simulated profiles obtained are in very good agreement with experimental results found in the literature.