Thermal fly-height controlled glide for disk defect detection and defect size estimation for hard disk drives

Current hard disk drives use thermal fly-height control (TFC) during read/write operations. In this study, we use TFC technology during the disk glide process to determine sub-5 nm height defects. We also utilize TFC to measure the height of the defect during glide operation. Additionally, we magnetically mark the disk locations where defects are detected for further post-processing of the defects using optical surface analysis, atomic force microscopy (AFM), and scanning electron microscopy (SEM). The defect height estimation during the glide was confirmed to be accurate by AFM and SEM analysis. Finally, we will present the TFC glide sensitivity showing capability of detecting smaller defects than conventional non-TFC glide technologies.