Innovated Methodology Improving CD Uniformity for Lithography Using Wafer-Less Dynamic Grouping Process Characteristics

This paper has proposed an intelligent methodology for inline high volume manufacturing (HVM), initiated by complexity of mature logic foundries. To improve on-product lithography performance, e.g. CD, Overlay, the conventional operation is to generate the compensation with intra-field and inter-field metrology result of real production wafer in process, which resulted in cost and cycle time loss. Logic foundries will have different product/process requirements which are having quite diversified process characteristics, causing intensive on-wafer-metrology and process correction setup accordingly. How to establish a flexible group/tracking/control system can increase ramping phase and improve yield within very limited cycle time is an universal challenge for years. We have initiated an inline control system, forecast the process variations with the main contributors without processed wafer and correct in advance. Such as to improve inline CDU performance, correct the hybrid intra-field and inter-field fingerprint which were estimated with mask CD and process characteristics. Also combined with context information from process model other than lithography as grouping index database, which is trackable indicator used as Run-to-Run (R2R) tuning parameters.