Pattern creation
To create a desired pattern nanotechnology researchers use e-beam lithography and have conventionally traced a pattern within a layer called a "resist," which is then etched into the underlying substrate. But the resist is thin and fragile and hence intermediate "hard mask" is generally laid between the resist and the substrate.
The hard mask sticks to the substrate long enough for the desired features to be etched and then it id cleanly removed. But the extra layer often results in a dull, rough and costly.
A new technique
But researchers of Argonne's Center for Nanoscale Materials and Energy Systems Division have overcome this difficulty and developed a technique called sequential infiltration synthesis (SIS). This involves the controlled growth of inorganic materials within polymer films so that materials with unique properties and even with complex, 3-D geometries can be constructed.
The thin delicate resist film can be made robust by infiltrating it with inorganic material without an intermediate mask and creating very narrow features well over a micron deep using only a very thin, SIS-enhanced etch mask would be a breakthrough capability.
By combining sequential infiltration synthesis with block copolymers, molecules that can assemble themselves into a variety of tunable nanostructures, this technique can be extended to create even smaller features than are possible using e-beam lithography by designing a selective reaction between the inorganic precursor molecules and one of the components in the block copolymer.
This opens a wide range of possible applications for solar cells, electronics, filters, catalysts and all sorts of different devices that require nanostructures, but also the functionality of inorganic materials according to the re searchers.