Considering the efficiency and veracity of rules based optical proximity correction (OPC),the importance of rules in rules based OPC is pointed out.And how to select,to construct and to apply more concise and practical rules base is disscussed.Based on those ideas,four primary rules are suggested.Some data resulted in rules base are shown in table.The patterns on wafer are clearly improved by applying these rules to correct mask.OPCL,the automatic construction of the rules base is an important part of the whole rules based OPC system.
An efficient partitioning algorithm for mixed-mode placement,extended-MFFC-based partitioning,is presented.It combines the bottom-up clustering and the top-down partitioning together.To do this,designers can not only cluster cells considering logic dependency but also partition them aiming at min-cut.Experimental results show that extended-MFFC-based partitioning performs well in mixed-mode placement with big pre-designed blocks.By comparison with the famous partitioning package HMETIS,this partitioning proves its remarkable function in mixed-mode placement.
An algorithm named DPP is addressed.In it,a new model based on the concept of irregularity degree is founded to evaluate the regularity of cells.It generates the structure regularity of cells by exploiting the signal flow of circuit.Then,it converts the bit slice structure to parallel constraints to enable Q place algorithm.The design flow and the main algorithms are introduced.Finally,the satisfied experimental result of the tool compared with the Cadence placement tool SE is discussed.
