Maxtor's new slant on disk recording

Disk-drive maker Maxtor says it has reached a milestone in devising cost-effective platters for a next-generation technology called perpendicular recording.

The company announced Monday that its subsidiary, MMC Technology, has demonstrated a method of making disk-drive media for the new technology at roughly the same cost as media used in today's drives. With the new media and perpendicular recording technology, Maxtor said it is possible to more than double the amount of data that can be crammed onto a typical disk, from the standard 80GB per 3.5-inch platter to 175GB.

Ken Johnson, vice president of research and development at MMC Technology, said other companies may have ways of making perpendicular recording media, but not necessarily a means to do it cheaply. "As we know, in this industry, cost effectiveness is very important," he said.

Perpendicular recording involves arranging magnetic charges--which hold digital information--vertically on a platter. In a sense, the disk surface is made up of tiny magnets standing vertically. The approach contrasts with the current industry standard method, called longitudinal recording. In longitudinal recording, charges are arranged horizontally on the surface of the platter.

Perpendicular recording is decades old, but it has yet to be widely used. The disk-drive industry has enjoyed rapid advances in data density without it. For example, data density doubled annually in the late 1990s. But the rate of growth has slowed, thanks partly to technical challenges.

Perpendicular recording has had its own challenges. One relates to the "soft underlayer" of magnetic material that helps a perpendicular recording head to write and read charges on the disk. Johnson said researchers have thought the underlayer needed to be as thick as 400 nanometers. Given that the final top layer of magnetic material is about 30 nanometers, the underlayer represented a relatively large amount of material to deposit on a platter, he said.

Using novel compositions and structures for the soft underlayer, Maxtor was able to reduce the thickness to 100 nanometers, he said. "That makes it 'make-able' in today's equipment," he said.