Researchers in Singapore have developed a nanopatterning technique that enables hard disk drives to store potentially up to 3.3 Terabit/in2 of information, which is six times the recording density of current devices. In collaborative research between Singapore’s Institute of Materials Research and Engineering (IMRE), the National University of Singapore (NUS) and the Data Storage Institute (DSI), the researchers have been able to demonstrate data-storage capability of 1.9 Terabit/in2 and fabricated bits capable of up to 3.3 Terabit/in2 densities. “What we have shown is that bits can be patterned more densely together by reducing the number of processing steps,” said Dr Joel Yang, the IMRE scientist who heads the project.
The process that the researchers came up with, published in the Institute of Physics journal Nanotechnology, involved the use of a high-resolution electron-beam lithography followed directly by magnetic film deposition. This essentially enabled the researchers to avoid the pattern transfer processes, such as etching and liftoff that manage to lessen pattern fidelity.
But the trick was in Yang’s discovery that by adding sodium chloride to the developed solution used in the lithography, “he was able to produce highly defined nanostructures down to 4.5 nm half pitch, without the need for expensive equipment upgrades.”
Yang happened on this idea not during this research project but back when he was a graduate student at the Massachusetts Institute of Technology—and published it back in 2005.