Application of optical proximity correction technology

As process technology scales down to very deep sub-micron(VDSM)in semicon- ductor manufacturing technology,intrinsic size becomes close to or even shorter than the wavelength used for optical lithography.Thus,some distortions and de- formations are introduced by optical proximity effects(OPE)mainly caused by the diffraction and interference of exposure light when layout patterns on a mask are transcribed to a wafer,which influence on the yield and performance of IC circuit.In order to compensate for the deformations,optical proximity correction(OPC)is the most commonly used methodology.Presently,the OPC method is to use a unitary toleration on the whole chip layer,which makes the run time of OPC algorithm longer,causes the size of GDSII files to follow exponential growth,and results in the cost of making mask grow immensely.Firstly,this paper proposes a self- adaptation OPC method with preprocessing function of patterns classification. According to the need of the correction precision,the OPC system divides patterns corrected into two groups with different toleration:critical patterns and general patterns,which enhance the efficiency of the OPC approach.Secondly,a model-based OPC method is presented based on pattern subsection and classifi- cation,which keeps the precision of the correction as well as enhances the effi- ciency.We also propose a rule-based OPC method with general,concise and com- plete correction rules,and achieve automatic-built rules-based and its looking-up. Thirdly,we also implement an OPC system,called MR-OPC;the MR-OPC system integrates both rule-based OPC and model-based OPC into a whole,so it can solve the confliction between the efficiency and precision.Experimental results show that the MR-OPC system we suggested has advantages of the efficiency and ex- pansibility.