How Do Multi-Beam Mask Writers Enable Curvilinear Shapes On Photomasks?

Why multi-beam mask write time becomes constant no matter how complex the mask shapes.


Multi-beam mask writing was identified as one of the ways to eliminate hurdles to manufacturing curvilinear mask shapes in the last installment of this blog. Our blog series continues with an educational video explanation of why and how multi-beam writers reduce write time for curvilinear mask shapes that took place during an eBeam Initiative panel discussion with industry experts during the 2021 SPIE Advanced Lithography Conference. In this two-minute video excerpt from the virtual event shown in figure 1, Noriaki Nakayamada, senior technology expert in the mask lithography engineering department at NuFlare Technology, explains how multi-beam mask write time becomes constant no matter how complex the mask shapes, including curvilinear shapes.

Fig. 1: Discussion on multi-beam mask writers during the 2021 eBeam Initiative panel at SPIE.

More throughput for EUV masks was identified as the number one driver for purchasing multi-beam writers in an eBeam Initiative survey of industry luminaries conducted in July 2020 (figure 2).  Curvilinear ILT for 193i masks ranked as the third reason followed by curvilinear ILT for EUV masks in fourth place.  In a separate survey question, an overwhelming majority of the survey respondents think that curvilinear shapes will be used on masks by 2023, at least partially.

Fig. 2: eBeam Initiative 2020 survey ranking reasons for multi-beam mask writer purchases.

Over the next few months in this blog, we will hear from experts at TSMC, Micron Technology and D2S in addition to NuFlare Technology as we explore questions about the readiness of the rest of the mask ecosystem, how the industry is working on solutions such as curvilinear data formats, and whether EUV masks will use curvilinear shapes. 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.

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