Nikon Precision Equipment Company Development Headquarters’ GM Masato Hamatani discussed the challenges and requirements associated with 10/7 nm node manufacturing at the recent LithoVision symposium. Explaining that the “internet of things” will lead the next wave of wafer consumption, Hamatani highlighted the need for continuing innovation to support developing applications and devices. Historically, lithographic scaling has driven device performance, with new technologies inserted frequently over the past decade (Figure 1A). Scanner advancements have yielded 11x productivity improvements and 40x accuracy improvements over a twenty year period. Hamatani noted that semiconductor devices will continue to evolve through further innovations, and ongoing scanner enhancements will make this possible.
A review of the key scanner requirements at the 20 nm, 16/14 nm and 10/7 nm logic nodes identified the need for continuous reduction in overlay and focus control (Figure 1B). Hamatani showed data indicating that the new Nikon scanners would meet this need. When discussing the choice between 193i extension and EUV lithography, Hamatani reported that significant technical issues continue for EUVL, while its cost benefits are unclear. A 300 mm process step and cost comparison for EUVL double patterning (DP) was 2x higher than that of ArF immersion multiple patterning, and EUV DP results were even less favorable under 450 mm conditions (Figure 2A). Nikon Precision Equipment Company Sr. Vice President Toshikazu Umatate added later that from the overall cost perspective, new technologies are not always the best approach. He predicted that based on 10 years of success, 193 immersion will remain the low cost solution. He noted that 193 immersion multiple patterning (MP) is cheaper than EUV DP under most reasonable conditions, and with an accumulated installed immersion toolset of more than 600 units, there are tremendous opportunities for performance enhancements, asset extension, and tool reuse capabilities.
Hamatani reported that the Nikon lithography product roadmap will continue to satisfy customer requirements with ArF immersion and dry extension solutions, and 450 mm scanner development will bring benefits to 300 mm tooling also (Figure 2B). The Nikon immersion extension pipeline includes the NSR-S622D, a high reliability 193 immersion system based on the established Streamlign platform, which is already being used in volume production at 14 nm. Then, the recently launched NSR-S630D features a new design to deliver world-class performance and productivity with 2.5 nm mix-and-match overlay (MMO), enhanced autofocus control, and 250 wafers per hour (WPH) productivity. Together these immersion systems enable logic manufacturing at the 10/7 nm node. This was shown in tests prepared by Nikon and Toyko Electron demonstrating logic patterning at the 7 nm node using 193 immersion for the gratings and the line cuts (Figure 3A).
Hamatani explained that immersion will enable production beyond the 7 nm node with further innovations leveraging the proven Nikon Streamlign platform, coupled with Design-for-Yield solutions that use scanner-aware optimization and open-source collaboration with EDA vendors to deliver peak tool performance. Hamatani also detailed that ArF dry capabilities will be extended with the S3xxF scanner that will be available later in 2014, delivering 230 WPH throughput and unprecedented dry single machine overlay of 2.0 nm and 5.0 nm MMO.
450 mm scanner development is progressing on schedule, and Nikon will begin providing patterned wafers to the Global 450 mm Consortium (G450C) by the end of June 2014, followed by pilot line tooling in 2015 (Figure 3B). 450 scanner development will also bring benefits to 300 mm tooling. Hamatani concluded that immersion extension is the highest confidence solution and Nikon 193i extension will enable production beyond the 7 nm node, satisfying process node requirements in 300/450 mm. Investigations of other next-generation lithography solutions are occurring in parallel with ArFi extension development. In closing, he noted that Nikon 450 mm lithography tooling will be ready when the industry decides to make the transition.