Characterization of Contaminants by S-Sims Mapping for Magnetic Recording Devices

Abstract

ABSTRACTThe magnetic storage industry moved from particulate to thin fdm disks during the 1980's due to the trend toward higher density media. The disk dimensions also shrunk, from 350 mm to 95 mm and are expected to go down to 62.5 mm. The head-disk fly height will be reduced from 35 nanometers to below 10 nanometers during the coming decade. Contamination build-up on the disk, the head, and at the head-disk interface can create problems and may ultimately lead to head crashing. Therefore, it is important to build hard disk drives using very clean components. Some of the important components are the disk, the bearing, the head, the actuator, the comb, and the spindle. Hydrocarbon contamination is ubiquitous. Lubricants used can be collected by the head and may cause head print problems. Depending upon the curvature of the head and asperities on the disk, there will be head-disk interactions which can lead to smears on the disk surface. Build-up of such smears on the head and disk can reduce fly height and cause performance problems.Static Secondary Ion Mass Spectrometry (S-SIMS) is a powerful technique used to analyze both organics (characteristic fragmentation pattern) and inorganics (by mass number, including isotopic ratio). This approach is not possible with other analytical techniques. Further, the technique is surface sensitive and the detection limit is very low. This paper discusses S-SIMS mapping of smears and head prints following contact/start/stop (CSS) testing. The roles played by individual file components in generating smears are identified. S-SIMS can also be extended to contaminant analysis on silicon wafers, printed board circuits, etc.