LONDON – Directed self assembly of nanometer-scale structures is a promising method of lithography of the future but it has suffered to date from only allowing the creation of a few arbitrary shapes. Now researchers at Massachusetts Institute of Technology (MIT) have reported on how to create rectangular structures, with potential application for integrated circuits.
The method was developed by MIT visiting doctoral student Amir Tavakkoli of the National University of Singapore, along with two other graduate students and three MIT professors. The work is due to be published in the journal Advanced Materials in August.
The work overcomes a natural tendency for many materials to self-assemble in hexagonal shapes. The solution involves creating an array of posts on the surface that guides the patterning of the self-assembling polymer molecules. The technique can also produce features, such as arrays of holes in the material, on a pitch that is much smaller than can be achieved using conventional lithography, MIT said.
"This new technique can produce multiple [shapes or patterns] simultaneously," said Tavakkoli in an account of the work at the MIT website. It can also make complex patterns, which is an objective for nanodevice fabrication with fewer steps than current processes.
The approach may find a place in nanometer-scale lithograpy or to help pack more data into magnetic media by patterning the domains that store 1s and 0s, the report said.
A scanning electron microscope image shows a pattern produced by the MIT team's self-assembling polymer system.