Using design intent to qualify and control lithography manufacturing

One of the consequences of low-k₁ lithography is the discrepancy between the intended and the printed pattern, particularly in 2-D structures. Two recent technical developments offer new tools to improve manufacturing predictability, yield and control. The first enabling development provides the ability to identify the exact locations of lithography manufacturing "hot spots" using rigorous full-chip simulation. The second enabling development provides the ability to efficiently measure and characterize these critical locations on the wafer. In this study, hot spots were identified on four critical patterned layers of a 90nm-node production process using the Brion Tachyon 1100 system by comparing the design intent GDS-II database to simulated resist contours. After review and selection, the detected critical locations were sent to the Applied Materials OPC Check system. The OPC Check system created the recipes necessary to automatically drive a VeritySEM CD SEM tool to the hot spot locations on the wafer for measurements and analysis. Using the model-predicted hot spots combined with accurate wafer metrology of critical features enabled an efficient determination of the actual process window, including process- limiting features and manufacturing lithography conditions, for qualification and control of each layer.