scientists from the EU-funded research project SOUVENIR
take a new approach to smash the cost of leading-edge
nano-research at the sub-50nm scale. Experts are
tipping it could be the next-generation lithography
(NGL) technology to revolutionise chip manufacturing.
lithography is the Holy Grail of the semiconductor
industry. It will allow rapid, large-scale manufacture
of modern microchips at a sub-50nm scale. Industry
giant Intel has spent 15 years and millions of
dollars looking for it. A nimble team of dedicated
EU-funded researchers may well have found a relatively
low-tech but clever solution in three years at
a cost of just €2.3 million.
The current generation of electron beam lithography
(EBL) is relatively inexpensive – at
around €2 million per machine – compared with what it could cost for sub-50nm
alternatives. The new so-called soft ultraviolet (UV) imprint machine, developed
by the EU-funded SOUVENIR project could cost under €200 000
for a basic version. The tool will be used to produce novel and experimental
nanotech devices in universities and research institutes and later for small
manufacturing runs. Later generations of the tool could turn the semiconductor
and nanotechnology industries on their head.
"One approach we use [with this technique] can already form patterns down to
the 10nm scale," says Dr Markus Bender at Applied Micro- and Optoelectronics
(AMO) in Germany, and coordinator of IST project.
It will take a few years more research to know whether SOUVENIR's work will lead
to viable NGL, he told IST Results . But even with its first-generation
tool, the team has come up with the goods, with a new technology on the brink
Photolithography works by casting light through a mask to produce a pattern on
a chemically coated substrate. The light changes the chemical structure of the
substrate. Depending on the type of photolithography, either the lit or shadowed
chemical is washed away in the next step. In either case the result is a pattern
etched into the substrate. With nanolithography the patterns are invisible to
the naked eye and the vast majority of the world's microscopes. The result is
the tiny circuits in semiconductor chips.
SOUVENIR developed a new technique to create those patterns cheaply and effectively.
First, the substrate is coated with a low-viscosity, UV-curable resist (chemical
layer). Next, a soft polymer mould, or elastomer, is pressed against the coated
substrate in a process known as imprinting. UV photopolymerisation then takes
place to cure the resist to the substrate.
Because the mould is pressed against the resist, the system does not require
expensive 'deep' UV light sources, as used in the semiconductor industry, that
only work properly in a vacuum. The result is a low-cost pattern process at the
sub-50nm scale. But this comes at a price. The system is somewhat slow and further
testing may be necessary to prove it can replace current industrial photolithography
processes. But the potential is there for it to become the NGL.
"This is the first generation of the tool we developed and, with work, we can,
in principle, get much better, faster and more scalable results," says Dr Bender.
If he is right, it could provide a viable alternative to the complex approach
to NGL taken by Intel, for instance.