High-precision metrology systems for next-generation microchips
Collaboration between Carl Zeiss and PTB extended to EUV lithography
EUV optics during production process
November 30, 2012
BERLIN/Germany, OBERKOCHEN/Germany, 30.11.2012.
The Semiconductor Manufacturing Technology business group at Carl Zeiss and the German national metrology institute
Physikalisch Technische Bundesanstalt (PTB) will be expanding their cooperation in the future to include optics metrology
for EUV (extreme ultraviolet) lithography. The two institutions have signed a cooperation agreement for a further four years.
Together with its Dutch partner ASML, Carl Zeiss is working on the development of EUV lithography, an innovative technology for
generating integrated circuits on wafers using a wavelength of 13.5 nanometers. The lithography optics from Carl Zeiss are
integrated in a wafer scanner at the facilities of the global market leader ASML. The PTB supports Carl Zeiss with high-precision
measurements of EUV optical components using a new EUV beamline at the PTB’s very own electron storage ring,
the Metrology Light Source (MLS). The PTB and Carl Zeiss have been working together since 1998.
The PTB provides access to the measuring facilities required for the characterization of EUV optical components.
There are already a considerable number of electron storage rings worldwide, but the modern MLS operated by the PTB can rightly
claim to be the only one of its kind in Germany and one of only a handful around the world. The MLS, which produces synchrotron
radiation in the spectral ranges from terahertz to EUV, has been in operation since 2008. “Our biggest strength lies in
at-wavelength metrology, which our cooperation partners find particularly useful,” says Dr. Frank Scholze, who heads up the PTB
workgroup. “It enables us to characterize the optical components in the EUV operating wavelength rather than just using visible
light, for example. As a result, our measurements give a more direct description of the behavior of the optical components in the
Dr. Frank Rohmund, who heads up the metrology department at Carl Zeiss Semiconductor Manufacturing Technology, explains further:
“Because we work with such extreme levels of precision, optics measurement and qualification is an absolutely crucial issue in
our business. With EUV lithography, we're entering a new era of chip manufacturing: In the future, we will be providing the
capabilities to create structures measuring less than 20 nanometers.” EUV lithography is therefore the path that will allow
Carl Zeiss to keep Moore's Law going. It enables the continued miniaturization of chip structures, thereby helping to meet the
demands of the semiconductor industry to continue making microchips smaller, more efficient, cheaper and more environmentally
friendly. EUV is currently scheduled to move into production in the middle of the decade.
The PTB’s new EUV beamline, which is particularly suited to testing photodetectors and structured optical elements,
is also helping to meet these requirements. Since the completion of the start-up phase earlier this year, the beamline has
increasingly been used as a metrology system in joint EUV research projects. Significant demand from industry has also prompted
the PTB to further expand its storage ring measurement capabilities. With its combination of EUV reflectometers, scatterometers
and ellipsometers, the PTB will have a total of around 6,000 hours of synchrotron radiation measurement capacity available each
year for EUV metrology from mid-2013 onwards.
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