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Feb 04, 2005 at 09:00 PM |
Product Briefing Outline: Tokyo Ohka Kogyo Co (TOK)
has developed a process based on a new concept applying Shrink Assist
Film for Enhanced Resolution (SAFIER). SAFIER makes possible
microprocessing a generation ahead even while using today's exposure
wavelengths, according to the company.
Problem: The production process window for 193nm ArF lithography
image resolution and depth of focus (DOF) have become small enough to
become a critical yield limiting factor. A chemical process that
shrinks via hole and trenches would enable a larger process window for
a given technology node, enabling better features and improving yields.
Solution: Utilizing the thermal contraction effect induced by
heat treatment on SAFIER itself, the process simultaneously shrinks
photoresist patterns while improving their configuration. With SAFIER,
the photoresist patterns shrink while retaining pattern walls
verticality. SAFIER undergoes thermal contraction at temperatures below
the photoresist fluidization temperature, and therefore allows
processing at lower temperatures than in the thermal flow process.
Contraction rate does not fluctuate much with temperature variation,
SAFIER offers improved controllability of this contraction rate. Even
photoresist patterns with mutually different pitches (pattern
intervals) exhibit little difference in respect of the contraction
rate. Removal of SAFIER with pure water after shrinkage of the
photoresist patterns.
Applications: SAFIER is applicable to a diversity of processes (i-line, KrF, ArF, Bi-layer, EB and F2).
Platform: A combination of polymer shrink chemistry with thermal flow.
Availability: September 2004 onwards.
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