Using metrology capabilities of mask inspection equipment for optimizing total lithography performance

The demand for aggressive image placement accuracy and CD uniformity for each generation is being increasingly accelerated by DPT deployment. The method of the correction with the scanner is in effect devised by obtaining the CD and IP maps of each mask after the mask pattern is drawn. We are developing a technology that generates CD and IP maps for each mask from the image data of inspection equipment with the ultimate goal of "in-die overlay improvement" optimizing scanner as well as writer performances. We evaluated the positional measurement function by using NPI inspection system with the evaluation mask.