A novel test system for automated surface characterization of performance relevant defects

摘要

The amount of data that hard disk drives (HDD) can store on a square inch of disk media is growing today at a rate of 100 percent per year. This progress is expected to continue for at least the next few years. Recently, an ultimate limit of 1 Terabit per inch{sup}2, equivalent to an area of 25× 25 nm{sup}2 for a single information cell was estimated by R. Wood for future magnetic recording technology of HDDs [1]. However, higher areal storage densities increase the relevance of smaller media defects and might play a major role in HDD performance. In particular, the decrease in distance of the write and read elements to the spinning media (a decrease from 20 nm to 5 nm is expected in the next 5 years) requires a very careful control of defect heights. Furthermore, anti-ferromagnetic coupled media may cause new types of defects, which cannot be detected by any topographic sensitive measurement technique.