Proposal of new style defect quality assurance for flat panel display photomask

Abstract

Since the mid-2010s, mobile organic light emitting diode (OLED) panels have increased the demand for increased resolution in Flat Panel Display (FPD) photomasks [1]. In response to this demand, a 1.5 um Line and Space target exposure system for 800ppi OLED panels ware released in the mid-2010s. In addition, exposure system manufacturers are developing 1.2um Line and Space target exposure systems to produce ultra-high-definition OLEDs in the 800-1000ppi range [2]. While photomask manufacturers are required to have defect assurance capabilities for the next generation design, there is no standard industry roadmap in the field of FPD lithography. We believe that what is really necessary for the OLED panels manufacturer is to ensure that the pattern on the photomask is transferred to the OLED panel without any problems. Instead of the assurance based on the size of the defect on the photomask, we propose a new type of photomask assurance, which is the assurance for the pattern transfer to the OLED panel by the photomask maker. In this report, we will report on our new type FPD photomask assurance proposal.