With the highly innovative Laser-Direct-Write process for 3D
nanostructuring from the dynamic new company, Nanoscribe GmbH, almost
any kind of three-dimensional structure can be produced from various
photo-sensitive materials. The optics company, Carl Zeiss AG based in
Oberkochen in Germany made a very positive move in acquiring just under
40 percent in the Nanoscribe start-up. Nanoscribe is based in
Karlsruhe, Germany.The new Laser-Direct-Write process for 3D nanostructuring was
originally developed for nanophotonics. This still relatively young 3D
laser lithography discipline is used in micro- and nanophotonics, life
sciences, biotechnology and microfluidics. This process is currently
being used, for example, in the production of three-dimensional
photonic crystals, or even for cell growth studies in specially
tailor-made spatial environments in biology.
Nanoscribe develops and produces compact rapid-prototyping laser
lithography systems for producing three-dimensional micro and
nanostructures in photoresists (picture 1). The company also offers the
design and production of structures in various photosensitive materials
that are specially customer-oriented, e.g. chalcogenide glasses, SU-8
or Ormocers as a service.
3D laser lithography uses multi-photon absorption for the local high
resolution illumination of photosensitive materials. The illuminated
areas have a different chemical solubility to their surroundings, so
that complex three-dimensional structures can be generated in the
sub-micrometer range. The process uses ultra-short laser pulses, which
have single-photon energy below the absorption threshold of the
photosensitive medium to be illuminated. The material is therefore
transparent for the laser light. If this laser beam is heavily focused,
however, then multi-photon absorption processes increase in the focal
volume. The material is chemically and/or physically modified at this
point, and therefore selectively chemical soluble vis-à-vis the
surrounding material.
As the photosensitive materials only first react after a specific
illumination level is reached, the process permits the production of
structure values that are significantly below the diffraction limit of
the optics used. Line widths of several micrometers down to 150 nm are
reached with 5 nm reproducibility. The processing volume depends on the
optics and the scanner configuration. 300 x 300 x 80 µm3 are
standard. Joining several processing volumes together allows surfaces
of up to 10 x 13 cm2 to be structured. Writing speeds up to 2 mm/s are
reached here.
The laser lithographs (picture 2) are set up as compact and
encapsulated systems, which can also be used in a clean room
environment with numerous workstations. The lasers used must be very
stable in their performance. Fiber lasers provide the best conditions
for this. With the acquisition of just under 40 percent of the
Nanoscribe GmbH start-up based in Karlsruhe, Germany, Carl Zeiss has
also secured the benefits of a future-oriented technology.
The two companies have been cooperating since 2007, and Nanoscribe
delivered its first system at the end of June 2008. Professor Martin
Wegener, one of the founders and scientific consultants of the
start-up, received the Carl Zeiss Research Award in 2006. In
addition to the investment, Carl Zeiss also supports the young company
with its wealth of know-how and experience. Nanoscribe has the
potential to open up new application fields in optical technologies.
The partnership with Carl Zeiss is a milestone on this path to the
future.
Bucky Ball – A symbol of the three-dimensionality of the innovative
laser lithograph process, now commercially available for the first
time.
Photo: Nanoscribe 
