Curvilinear Photomasks Can Be Made Today

Multi-beam mask writers (MBMWs) and GPU-accelerated curvilinear ILT are enabling curvilinear photomasks to be made today. Despite the benefits of improved process windows, curvilinear photomask adoption is slow. Industry luminaries surveyed by the eBeam Initiative in 2021 ranked photomask inspection and infrastructure as the top barriers to adoption, as shown in figure 1. Yet only 4% say the barriers are insurmountable and 71% say mask shops can handle a limited number of curvilinear photomasks. This 6-minute video, moderated by Aki Fujimura of D2S, recaps the importance of MBMWs in the adoption of curvilinear photomasks and discusses some of the barriers.

Tom Cecil of Synopsys believes there are many ways to improve the manufacturing chain to make more curvilinear photomasks. In particular, he thinks there are a lot of potential improvements to reduce data volume. When reflecting on the survey results shown in figure 1, Tom thinks they look more promising than comparable ones did for EUV several years ago.

Fig. 1: Barriers to adoption of curvilinear photomasks are surmountable, according to the eBeam Initiative Luminaries survey from July 2021.

Chris Progler of Photronics agrees with the survey result that photomask inspection is a top priority to address for wide-scale adoption of curvilinear photomasks. He puts photomask repair in the same bucket. Chris predicts a migration to image-based characterization and disposition to enable adoption of curvilinear photomasks. While there are barriers to address for wide-scale adoption, Chris says that a limited number of curvilinear photomasks are manageable by the mask makers today.

That completes the blog series covering this year’s eBeam Initiative SPIE Photomask Technology virtual event. Thank you to Aki Fujimura of D2S, Tom Cecil of Synopsys, Chris Progler of Photronics, and Mikael Wahlsten of Mycronic for providing insights into the 2021 eBeam Initiative’s Luminaries survey during the video panel discussion. You can watch the entire 82-minute panel video covering the additional topics of photomask market growth, EUV photomasks, and deep learning here.