A Method Of Substrate Aware Optical Proximity Correct For 55nm Node Implant Process

In the integrated circuit manufactory technology,traditional optical proximity correction is based on the flatten substrate.For the complicated substrate including active and STI area of implant layer,we use the method of approached optical proximity correction like the flatten substrate.By using this method,the critical dimension of the implant pattern will have deviation to the original design,even causes the lithography defect.The author introduces a hybrid method of optical proximity correction for implant layer.By model-based method to compensate the traditional optical proximity effect,and by rule-based method to compensate the deviation caused by the different substrate.Firstly,based on the design rule and circuit characteristic of the integrated circuit,and design one series of test patterns.These test patterns include the implant pattern covered minimum design rule,and the surrounding active and gate structure based on the design rule and circuit characteristic.And then tape-out active,gate and implant total three test masks.Use the active mask to manufactory the active and STI substrate,and use the gate mask to manufactory the gate substrate.Based on these two kinds of substrate,measure the CD deviation of implant layer pattern caused by the substrate.Analyze the data and then setup compensation table for this impact.Before implant layer optical proximity correction,add one rule-based target adjustment step to implement the compensation table and then form one new target layer.At last,use this new target layer to execute the model-based optical proximity correction.By testing the new flow on N type source/drain implant layer,the implant pattern deviation caused by substrate can be controlled within +/-10%.The result shows that the flow can forecast and compensate the implant pattern deviation successfully based on fixed STI and gate process.