- When will these HVM-level EUVL scanners be used to make products?
- What will trigger the industry-wide insertion of EUV scanners in HVM production lines?
- Will it be a certain source power level, throughput, yield, or cost that raises the confidence of users?
- Who will be the first users of EUVL in HVM, and for what products and which node?
Similar questions can be posed for EUVL mask defect metrology tools. With scanners, we have an approximate throughput model that is widely known, so we can estimate throughput and cost of ownership at a given source power level. This is not quite so for mask defection inspection tools, as they are still being designed and need brighter EUV sources. The leading option for sources for defect metrology tools (and the only one for a 24 x 7 operation) is the Energetiq Xe discharge-produced plasma (DPP) source. However, current performance levels for this source allow only development of prototypes.
In my opinion, memory makers probably will be the first adopters of EUVL technology. Throughput as high as 40 wafers per hour (WPH) will convince chip-makers that EUVL is a viable technology, and sales of EUVL scanners and associated tools and products will start soaring. Mask defect metrology tools will remain unready for HVM until a brighter source becomes available. We can expect a déjÃ vu: low throughout metrology tools waiting to be upgraded.
In the case of high-power sources, we have three major suppliers with the commitment and resources to continue development. Not so for metrology sources, and the end customers will have only themselves to blame this time. I have read that end users are spending up to $150 million on metrology tool development, but not a dime on developing EUV sources for metrology. A source supplier told me that promises of support for metrology source development have not materialized, even though EUV sources for metrology are the weakest link in the chain. With virtually all of the money going to engineering development of tools and none to this weakest link, the results are very predictable.
As the industry Roadmap moves to smaller nodes of resolution (10 nm and below), will we choose EUVL with double patterning, or change the wavelength once again and move toward Beyond EUV (BEUV)? Gadolinium (Gd) at 6.8 nm is the current leading option for BEUV source material, as we saw from the latest development results on source and optics in last year’s EUVL Source Workshop. Increased optical proximity correction (OPC), off-axis illumination (OAI), and double patterning may require more power at these nodes than 13.5 nm sources can provide, so it might make sense to move to BEUV. For BEUV, we have a leading source material for multilayer (ML) optics and resist development has already started. We also can apply lessons learned from 13.5 nm to BEUV tools, although more infrastructure work will be required.
These and related topics will debated by panelists from Intel, GlobalFoundries, Toshiba and Applied Materials (AMAT) at the 2012 EUVL Workshop being held June 4-8 in Maui, Hawaii. The panel will be moderated by Sushil Padiyar of AMAT. The Workshop also will feature many papers on BEUV and EUVL R&D from some of the world’s leading researchers. I will be blogging here about these new developments after the EUVL Workshop.