How Extensively Will Curvilinear ILT Be Used For EUV Photomasks?

Curvilinear shapes on photomasks lead to improved process windows, as the first installment of this blog series discussed. Our blog series continues with a video panel discussion of the benefits that curvilinear shapes have for EUV photomasks (masks) and whether curvilinear shapes will be used beyond today’s usage for hotspots.

Our panellists approached the question of curvilinear ILT for EUV from both a technical standpoint as well as the economic angle of extending the initial investment in EUV tools. In this five-minute video excerpt from the virtual eBeam Initiative panel, Danping Peng of TSMC and Ezequiel Russell of Micron Technology explain why they think some curvilinear shapes will be used on EUV masks (figure 1).

Fig. 1: Discussion on the reasons why EUV masks will contain some curvilinear shapes during the 2021 eBeam Initiative panel at SPIE Advanced Lithography.

The panel went on to discuss whether curvilinear ILT would be used beyond “hotspots” for an entire critical layer. Danping Peng discussed the ILT runtime challenge but pointed to GPUs as a solution to the barrier while Ezequiel Russell predicted that full-chip curvilinear ILT usage for critical layers will increase because more multi-beam mask writers will be in use. To hear more of their insights on how extensively curvilinear ILT will be used and when, you can watch this four-minute video excerpt from the panel discussion.

Over the next few months in this blog, we will continue to bring you the viewpoints from experts at TSMC, NuFlare Technology, Micron Technology, and D2S as we explore questions about the challenges of curvilinear shapes on photomasks and how the industry is working on solutions such as curvilinear data formats. Our final blog will look at the potential to change not only manufacturing but also the design of semiconductor chips using curvilinear shapes. If you can’t wait, you can watch the full 90-minute panel event here.