This is where block copolymers come in. At room temperature, coated on a disk surface, they don't look like much. But if they're designed in the right way, and given the right prod, they'll self-assemble into highly regular patterns of dots or lines. If the surface onto which they're coated already has some guideposts etched into it, the dots or lines will form into precisely the patterns needed for a hard disk drive.
This process, which is called directed self-assembly (DSA), was pioneered by engineers at the University of Wisconsin and the Massachusetts Institute of Technology.
When Willson, Ellison and their students began working with directed self-assembly, the best anyone in the field had done was to get the dots small enough to double the storage density of disk drives. The challenge has been to shrink the dots further and to find processing methods that are compatible with high-throughput production.
The team has made great progress on a number of fronts. They've synthesized block copolymers that self-assemble into the smallest dots in the world. In some cases they form into the right, tight patterns in less than a minute, which is also a record.
"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."
Most significantly, the team has designed a special top coat that goes over the block copolymers while they are self-assembling.
"I've been fortunate enough to be involved in the experimental work of the top coat project from its inception all the way to our final results," said Leon Dean, a senior chemical engineering major and one of the authors on the S
|Contact: Daniel Oppenheimer|
University of Texas at Austin