EUVL is being inserted in manufacturing in 2019: What are the mask related challenges remaining?

As it has been widely announced by the leading foundries, and confirmed by ASML, EUV Lithography is being introduced into high volume manufacturing (HVM) since the beginning of this year, in order to enable a more cost-effective manufacturing for the 7nm logic technology node. Very soon, the next technology node will be introduced and the number of EUV layers at 5nm is expected to increase significantly. Although EUV masks are not regarded as the first critical issue for EUV introduction into HVM, several items with respect to EUV masks need more time for improvements, certainly for 5nm and beyond. This presentation will address several mask related items such as EUV pellicle, alternative absorber, EUV mask lifetime, etc... and finally anamorphic masks. This paper is reviewing the status and outlook for these remaining challenges.