Comparison of OPC models with and without 3D-mask effect

OPC models with and without thick mask effect (3D-mask effect) are compared in their prediction capabilities of actual 2D patterns. We give some examples in which thin-mask models fail to compensate the 3D-mask effect. The models without 3D-mask effect show good model residual error, but fail to predict some critical CD tendencies. Rigorous simulation predicts the observed CD tendencies, which confirms that the discrepancy really comes from 3D-mask effect.