The Application And Optimization Of Sub-Resolution Features In Optical Proximity Correction For 65nm IC Technology And Below

As the decreasing of Critical Dimension for the integrated circuit manufacturing,the lithographic process window is becoming one of the most important criteria in mass-production to evaluate the reliability and stability of products.In order to keep resolution and overcome the lack of DOF issues,double patterning and illumination optimization techniques are widely applied in production.For 65 nm node IC technology and below,Sub-Resolution-Assist-Features techniques are applied in Optical Proximity Correction as one of the process window enhancement techniques.Rule-based and Model-based SRAF are two types of commonly used techniques;these two SRAF approaches have their own individual advantages and disadvantages.The prerequisites to ensure stable production for the semiconductor manufacture foundry is how to choose the most appropriate techniques.This paper first reviewed the development of resolution enhancement techniques and process-window-enhancement techniques for the advanced contact-hole layer.In addition,based on the theory of Rule-based SRAF and Model-based SRAF,we propose one hybrid approach for SRAF OPC technique from the design and tape-out of test mask to the selection of SRAF parameters and to the model setup and verification.This hybrid SRAF OPC approach shortens 60% OPC run time,enhances tape-out efficiency,and eventually brings economic benefits to the company on the premise of both keeping accuracy for SRAF inserts and OPC correction.