Dr. Burn Lin, VP of TSMC, was the keynote speaker at KLA-Tencor's annual Litho Users' Group forum. Among the topics he covered was a comparison between multi-ebeam and EUV lithography for future nodes. Lin first noted that economics will drive the decision at the 16nm node - whether to use EUVL or MEB ML2. However, at 8nm, EUVL has better resolution, MEEF, DOF, and overlay margin, while MEB has the potential for better CDU and OL accuracy.
EUV needs more source power to compensate for throughput loss per node, which breaks down as follows: a 2x loss due to shot noise, and a 2x loss due to the need for more mirrors at higher NA lithography. MEB needs either more parallelism or source brightness to compensate for its throughput losses per advancing node; MEB's throughput losses per node break down like this: MEB's problems are due to a 2x loss because of the huge volume of data generated by the process (e.g., the data rate is >7.5Gbps/beam - in the MAPPER tool, for example, a single electron source is split into 13,000 Gaussian beams), and there is a 2x loss due to shot noise.
The last two points are probably obvious: EUVL has a high cost and MEB is less developed as a technology. (DV)