P‐108: Development of Photomask Quality‐Assurance System Using Aerial Image Analysis

According as phase‐shift layer and OPC techniques are applied to photomasks for novel display with a resolution of higher than 1000ppi, it is indispensable to qualify photomask printability of area of interest‐ especially the area where the photomask repair processes were performed ‐ before the photomask is used in panel manufacturing line[1]. For this photomask qualification, new imaging system to emulate photo exposure process was developed; which enables to assess the printability of photomask by analyzing the aerial image. To verify the results from the imaging system, simulation and analytical solution were performed with various optical parameters such as NA and coherence. As an application of the imaging system, how to quantify the pattern abnormality using process window analysis and to measure in maskshop the mask error enhancement factor in aerial image was introduced.