Nikon tips 193-nm immersion tool, illuminator
Nikon and rival ASML Holding NV are going toe-to-toe in lithography, but the two the companies have markedly different strategies. ASML is pushing hard to bring EUV to the 22-nm node, but Nikon believes that the technology will not be ready until the 16- or 11-nm node. ”Nikon anticipates a delay in EUV ecosystem readiness,’’ said Yuichi Shibasaki, general manager of the Next Generation Development Department for Nikon.
So, Nikon is pushing for optical solutions amid a rebound in its business. In optical, Nikon is currently shipping its previously-announced S620D, a 193-nm immersion tool for the 32-nm node and beyond. The S620D boasts a 1.25 numerical aperture (NA) and a throughput of 200 wafers an hour.
Customers reportedly include Intel, Globalfoundries and Samsung. The tool is reportedly being used for the development of Intel’s 22-nm logic node. With a different tool, Nikon was the sole lithography vendor for the critical layers at Intel’s 32-nm node.
At 22-nm, however, Intel will reportedly use two lithography vendors for the critical layers. Besides Nikon’s S620D, Intel is reportedly also using 193-nm immersion scanners from rival ASML.
At LithoVision, Nikon tipped a new 193-nm immersion tool, dubbed the S621D. The S621D can be ordered as a standalone system. The current S620D is a modular system that can be upgraded to an S621D tool.
The S620D has demonstrated overlay performance, and achieved across-lot overlay data below 2-nm, as well as lot-to-lot stability data across three lots ≤ 2.2-nm (3σ)–fully satisfying 32-nm manufacturing requirements and approaching 22-nm targets.
Like the S620D, the S621D boasts an NA of 1.25. But the S621D improves the overlay requirements for the 14-nm logic node. During a presentation, Nikon’s Shibasaki tipped several ”tuning and optimization knobs’’ within the tool, which is said to boost performance and overlay. This includes an intra shot grid, dynamic lens control, an adaptive reticle chuck and aberration control, he said .
In addition, Nikon also expanded its source-mask-optimization (SMO) efforts by rolling out a ”freeform illuminator.’’ Dubbed iPure, the technology adjusts the illumination in a scanner ”on the fly,’’ said Hamid Zarringhalam, executive vice president of Nikon Precision Inc.
Like ASML, Nikon is developing EUV. ASML has shipped two alpha tools, including one to Albany Nanotech and another to IMEC. ASML has recently shipped its first standalone, pre-production EUV tool to Samsung Electronics Co. Ltd.
Nikon is not shipping standalone EUV tools. Instead, the company has devised two R&D tools, including one within its headquarters in Japan and another at Japanese R&D organization Selete.
For some time, Nikon has been developing its EUV tool, dubbed the EUV1. The company sees the insertion of EUV for the 11-nm ”half-pitch” node at 2015. At Lithovision, Nikon, in collaboration with Canon, said they have developed an actinic wavefront metrology technology for EUV. Dubbed Multi-Incoherent-Source Talbot Interferometer (MISTI), the technology is still in the R&D stage.
