UV NIL shows excellent resolution capability with remarkable low line edge roughness, and has been attracting pioneers in the industry who were searching for the fi nest patterns.We have been focused on the resolution improvement in NIL template making with a 100keV acceleration voltage spot beam EB writer process, and have established a template making process to meet the requirements of the pioneers. Usually such templates needed just a small fi eld (several hundred microns square or so). Now, for several semiconductor devices, the UV NIL is considered not only as a patterning solution for R&D purpose but eventually as a potential candidate for production, and instead of a small fi eld, a full chip fi eld mask is required. Although the 100kV EB writers have excellent resolution capability, they are adopting spot beams (SB) to generate the pattern and have a fatally low throughput if we need full chip writing.In this paper, we are focusing on the 50keV variable shaped beam (VSB) EB writers, which are used in current 4X photomask manufacturing. The 50keV VSB writers can generate full chip pattern in a reasonable time, and by choosing the right Continues on page 3. Historically, many people in semiconductor industry took it for granted that mask making was straight forward. They believed mask making was never a challenge especially when compared to other lithographic technologies. However, next generation lithography (NGL) proved that masks were diffi cult to fabricate. Why? Because NGL masks became one of the main failure reasons of NGLs, such as XPL and EPL, or IPL. The question is whether a similar thing will happen with double patterning (DP) technology and EUV lithography.Double patterning was proposed because it enabled pitch relaxation. Combine pitch relaxation with immersion exposure, and 32-and 22-nm technology nodes seem achievable. Resolution is improved but now the real challenges are transferred to mask making process. When we use one mask to execute the exposure, we require good CD uniformity on the mask. However, when we use two masks to generate one pattern (as with double patterning) we need to control the combined CD of a pair of double-patterning masks; which requires perfect CD Mean to Target (MTT) from the pair DP masks. For example, ITRS requires the difference in CD MTT of two DP masks be smaller than 1.3 nm and 0.9 nm for 32 and 22 nm, respectively.A current mask fabrication tool set would include a 50 kV e-beam writer, a ICP-bias power plasma etcher, a deep UV inspection tool, a FIB repair tool, and wet-megasonic cleaning tool. These confi gurations have been used for both 130nm and 90-nm technology nodes. Improvements have been made gradually for every technology node, but there has been no revolutionary progress. The question is: How far can these confi gurations go? Can these tool sets be used for 32-and 22-nm technology nodes?Let's break down the CD MTT budgets of mask fabrication processes which affect the fi nal CD values on the masks. For e-beam exposure, the dose is the mo...