Bending The Rules With Curvilinear Technology

TSMC’s Danping Peng looks at the historical hurdles for this technology.


What have been the historical hurdles for curvilinear ILT?

Danping Peng, director at TSMC, reflected on his early involvement in the development of ILT and the three major hurdles encountered while at Luminescent during a panel discussion with industry experts at the eBeam Initiative’s annual event during the 2021 SPIE Advanced Lithography Conference. Among the topics covered, the panel discussed the historical hurdles and trade-offs between curvilinear ILT improvements to depth of focus (DOF) and the increased photomask write times using a variable shape eBeam (VSB) writer (Figure 1). In this six-minute video excerpt from the virtual event, Danping Peng concluded that the major hurdles to curvilinear ILT have been largely addressed through GPU acceleration and multi-beam mask writers.

Figure 1: Discussion of historical curvilinear ILT trade-offs at the 2021 eBeam Initiative panel at SPIE.

Last July, industry luminaries representing 42 companies from across the semiconductor ecosystem participated in the 2020 eBeam Initiative Luminaries survey. These luminaries were asked to reflect on multiple questions including how broadly they believe ILT was being used in 2020. The majority opinion was that at least a few critical layers used ILT (Figure 2). Did that mean ILT was only used for hot spots? A survey can only tell you so much but our panelists were able to discuss this question in more depth in an upcoming blog to provide you more insight.

Figure 2: eBeam Initiative survey result reflecting the opinion of Luminaries on the usage of ILT.

We will continue to explore questions about curvilinear mask shapes in future installments of this blog. How multi-beam mask writers handle curvilinear shapes, the extent the industry will adopt curvilinear shapes beyond hotspots, and whether EUV masks will use curvilinear shapes will be addressed by experts at NuFlare Technology, Micron Technology and D2S in addition to TSMC. If you can’t wait, you can watch the full 90-minute panel event here.

The Quest For Curvilinear Photomasks
Why this technology is vital for chip scaling, and what problems still need to be resolved.

Leave a Reply

(Note: This name will be displayed publicly)