Issue



Nanoimprint lithography???s role in 450mm


09/01/2012







During SEMICON West in July 2012 there was increased momentum and growing industry consensus on the timing for the 450mm wafer transition. This broad support is a necessary milestone that helps mitigate risk but it does not guarantee timely innovation. Coordinating the 450mm wafer size transition with Moore???s Law has never been more complicated, especially for advanced lithography. Equipment companies are not eager to repeat the ???bridge tool??? mistakes of the 300mm transition, yet 193i has all but reached the end of its resolution roadmap (forcing adoption of self-aligned multiple patterning schemes) and EUV remains elusive. While the industry is addressing this conundrum by hedging on both these optical technologies, neither solves the immediate problem of orchestrating an efficient 450mm wafer transition. Developing tools for the future (etch, deposition, CMP, metrology, etc.) require patterns from the future on 450mm wafers today. Fortunately, nanoimprint lithography has made impressive progress over the last twelve months and is currently being groomed for advanced FLASH production with 300mm system installations at two of the largest semiconductor memory manufacturers.


Consequently, Molecular Imprints Inc. (MII) was awarded a contract in November 2011 from a leading IC manufacturer for the industry???s first 450mm lithography tool. The advanced patterned large wafers from this tool will support the development of the industry???s 450mm equipment solution beginning in Q4???2012.


In selecting a 450mm lithographic technology for these critical test wafers several factors such as resolution, extensibility, cost and availability were considered. EUV???s protracted technical challenges and associated costs eliminated it as a viable option while 193i lithography did not satisfy the near-term 450mm availability and long-term resolution requirements. Fortunately imprint lithography has recently made significant progress and is able to meet all of these requirements. Molecular Imprints Jet and FlashTM (J-FILTM) technology has shown its flexibility to adapt to a variety of substrate sizes from 65mm hard disk drive platters to the much larger flat panel displays substrates. J-FIL is being slated for advanced semiconductor pilot-lines in the next 18 to 24 months by early adopters in an effort to stem rising costs and schedule risks of optical lithography.


Several equipment companies have opted to baseline J-FIL on their existing platforms using 300mm wafers. Once their imprinted pattern transfer processes have been characterized on 300mm tools then any identified imprint nuances can be decoupled from their specific 450mm form factor challenges. We expect this baseline activity to be very straight forward as J-FIL resist is very similar to 193 resists. Molecular Imprints intends to provide 300mm patterned wafer services in Q4???2012 that will closely correlate (in terms of mask designs and imprint process conditions) to the actual 450mm J-FIL platform.


In summary, nanoimprint is the only lithography that is currently capable of syncing the future???s advanced patterned features with the pending 450mm substrate transition. Early access to these advanced test wafers is paramount for equipment companies to efficiently develop their 450mm toolsets without neglecting Moore???s Law. The low cost and extensibility of J-FIL lithography provides a long technology roadmap for advanced memory manufacturers while enabling the broader semiconductor industry to begin its 450mm initiative.


Paul Hofemann


PAUL HOFEMANN VP Corporate Marketing and Business Development, Molecular Imprints, phofemann@molecularimprints.com


Solid State Technology, Volume 55, Issue 7, September 2012