SEMATECH
engineers have made significant advances in moving forward the
infrastructure that will prepare extreme ultraviolet lithography (EUVL)
for cost-effective manufacturing, according to papers being presented
here at the 2007 International EUVL Symposium.
An outstanding set of SEMATECH-led technical achievements and
breakthroughs in EUVL are featured in nine papers from SEMATECH authors
and seven partner papers involving lithographers from the global
consortium. The research leading to these accomplishments took place at
SEMATECH’s facilities at the College of Nanoscale Science and
Engineering (CNSE) in Albany, NY, and demonstrates the
consortium’s commitment to deliver cost-effective
manufacturing solutions to its member companies and the semiconductor
industry.
“SEMATECH continues to produce results that
chip-makers need to show that EUVL is manufacturable,” said
Michael Lercel, Lithography director. “Here at the EUVL
Symposium, we’re showing practical results for mask blank
defect reduction, more efficient optical system designs, effective
reticle handling, and other areas that help drive cost, which is
emphasized in our cost-of-ownership models.”
“The significant advances made by SEMATECH
researchers and engineers working at the UAlbany NanoCollege
demonstrate SEMATECH’s leadership in spurring next-generation
advances in nanoelectronics, which is enhanced by its growing presence
and partnership at CNSE’s Albany NanoTech,” said
Dr. James G. Ryan, professor of nanoscience and associate vice
president of technology at CNSE. “This represents another
important step forward in the development and commercialization of EUVL
technology, which is seen as vital to the future of nanoelectronics
manufacturing.”
Following is a sampling of advances revealed by SEMATECH
technologists in papers being delivered at the symposium:
- The best EUV mask blank defect density in the world today
– 0.1 per cm2 at 56 nm resolution – will be
reported by Chan-Uk Jeon, program manager of the Mask Blank Development
Center in Albany, NY. SEMATECH also has created a detailed database of
the source of the defects and is developing mitigation methods, such as
smoothing, to reduce pit defects. (This SEMATECH smoothing process has
achieved an 800X improvement in defect levels.) SEMATECH’s
work likely will enable mask blanks to be ready for EUV beta tools in
2009.
- SEMATECH has achieved only five added defects at 56 nm
sensitivity in EUV mask blank defect totals, according to a paper by
Patrick Kearney, Member Technical Staff. This milestone was enabled
with industry-leading 56 nm defect inspection sensitivity on multilayer
coated blanks, and is rooted in SEMATECH’s strategy of
collaborating with suppliers to bring together all elements of the
industry.
- A manufacturable EUVL reticle solution also requires
defect-free reticle handling. EUVL reticle protection using
SEMATECH’s “sPod” design shows an average
of less than one particle added per 100 separate reticle transfers, as
explained in a paper by Long He, project engineer. Tests also show the
sPod as a potential solution for shipping and storage.
- Using the industry’s best EUV resist exposure
capability, SEMATECH has demonstrated that effective resolution down to
24 nm can be achieved with current resists and optimized illumination
conditions. These results are documented by Andy Ma, EUV resist bench
project manager. Ma also describes remaining resist challenges,
including linewidth roughness and photospeed.
- Current optical designs for EUV collectors are not very
efficient, but SEMATECH has developed a series of upgrades that could
boost collector efficiency by 2.8X. That would reduce the
industry’s critical dependence on high-power sources or
improve tool throughput and cost-effectiveness. The designs are
explained in a paper by Michael Goldstein, Senior Technologist.
- Detailed cost-of-ownership targets for EUVL – as
determined by SEMATECH’s detailed cost models –
will be reported by Phil Seidel, Senior Member Technical Staff. These
performance targets have been integrated into the
consortium’s technology development projects, and show that
the key elements for cost-effective EUVL include source power, optics
lifetime, and mask blank defect reduction.
“SEMATECH continues to move beyond theory and alpha
concepts to deliver manufacturable EUV solutions for our member
companies and the industry,” Lercel said. “We are
leading EUV mask blank development with the world’s best
defect inspection and characterization capability and multilayer
deposition capability, and leading-edge imaging capability for EUV
photoresists.”