Study of the Adsorption of Siloxane and Hydrocarbon Contaminants onto the Surfaces at the Head/Disk Interface of a Hard Disk Drive by Thermal Desorption Spectroscopy

The adsorption of siloxanes and hydrocarbons, which are common harmful contaminants found on hard disk drives (HDDs), has been investigated by thermal desorption spectroscopy (TDS). The desorption energy of each molecule from various modeled surfaces at the head/disk interface (HDI) was determined. The surfaces studied in this literature were (a) hydrogenated amorphous carbon (a-C:H), (b) a-C:H with perfluoropolyether (PFPE) and (c) a nascent surface of a-C:H. Considerable variations in the monolayer desorption energy of a siloxane model compound were observed. The monolayer desorption energy of a siloxane model compound from a plain a-C:H surface is higher than that from an a-C:H surface with perfluoropolyether, while that from a nascent a-C:H surface is far higher than that from an a-C:H surface. Meanwhile, the monolayer desorption energy of a hydrocarbon model compound from a-C:H is a little bit higher than that from a-C:H with perfluoropolyether. These results suggest that the adsorption of these harmful contaminants can be decreased by the control of HDI surfaces, and therefore we can reduce the risk of failure of HDDs.