Self-assembling nanowires

Researchers at the National Institute for Nanotechnology (NINT) have demonstrated a new technique for producing very small conductive nanowires on silicon chips.


The scientists have found a way to use molecules that self-assemble to form lines, which can then be used as wires. The work coincides with the trend for technology platforms to become increasingly smaller.


‘Computer chips are constantly getting smaller and smaller. There’s an unrelenting decrease in size. And the question arises, how do you wire these things in?’ said Dr Jillian Buriak, University of Alberta professor and senior research officer at the National Institute for Nanotechnology. ‘If you’re going to make something on the order of 22 or even 18 nanometres, then you’d better have a plug that’s about that size, too.’


Using the new technique, nanowires that are 5,000 times longer than they are wide can be produced, and with these wires smaller transistors and other electronic components can be developed.


‘You need very tiny wires to connect everything,’ said Buriak.


‘We’ve figured out a way to use molecules that will self-assemble to form the lines that can be used as wires. Then we use those molecules as templates and fill them up with metal, and then we have the wires that we want. You use the molecules to do the hard work for you.’


Buriak demonstrated the theory by using the technique to make 25 parallel platinum nanowires, with each wire measuring 10nm in width and 50µ in length.


She also explained that the ‘self-assembling’ technique is actually a natural process.


‘You are the product of self-assembly. The way DNA forms a double helix is self-assembly. It’s just that molecules will recognise each other, bind to each other and then they’ll form structures,’ said Buriak. ‘The molecules we’re using are very simple. They’re just polymers, just plastics that do that naturally.”


As well as providing a solution for computer manufacturers looking for ways of increasing the speed and storage capacity of electronics, Buriak said that the new technique would also make electronics cheaper.


‘If you have to go and lithographically define one single wire, it’s going to be painstakingly hard and expensive. But, if you can have a cheap molecule do it for you, that’s going to be much cheaper, use much less energy and be a little more environmentally friendly,’ she said.