A comparison of film structure and surface chemistry of carbon and oxide disk overcoats

Satisfactory durability and stiction results have been obtained with hydrogenated carbon, zirconia, and silica overcoated disks lubricated with a perfluoropolyether with functional end groups. Higher levels of lubricant bonding at room temperature are observed on silica and zirconia surfaces. It is believed that this is related to the high levels of surface OH for these overcoats. The lubricant affinity for the overcoat is believed to be a primary factor in the durability and stiction performance of the disk. Thus, oxide overcoats should have an inherent advantage over diamond-like carbon because of surface chemistry; however, processing restrictions such as the need for RF sputtering and sensitivity to sputter defects make their use less attractive