According to Wilson, when the UT Austin team began working on DSA, the technique had been previously used to double the storage density of disk drives. The team was able to significantly improve on that by furthering shrinking the dots further and finding processing methods compatible with high-throughput production.
In addition to synthesizing block copolymers that self-assemble into the smallest dots in the world, the UT Austin researchers have in some cases induced them to form into the right, tight patterns in less than a minute, they say. The team also reported that it has designed a special top coat that goes over the block copolymers while they are self-assembling, allowing them to achieve the right orientation relative to the plane of the surface simply by heating.
Comparison of the block copolymers self-assembling with and without the new top coat. In both cases the self-assembly took place under very simple conditions: 210°C for 1 min on a hot plate open to air.
Credit: University of Texas-Austin
"I am kind of amazed that our students have been able to do what they've done," said Willson. "When we started, for instance, I was hoping that we could get the processing time under 48 hours. We're now down to about 30 seconds. I'm not even sure how it is possible to do it that fast. It doesn't seem reasonable, but once in a while you get lucky."
The researchers' work was described this week in the journal Science in a paper co-authored by Wilson, chemical engineering professor Chris Ellison and a team of graduate and undergraduate students. It's also being given a real-world test run in collaboration with HGST, formerly Hitachi Global Storage Technologies, now a subsidiary of disk drive marker Western Digital Corp.