Silicon nitride/tetrahedral amorphous carbon bilayer overcoat for exceptional wear life of functional tape heads

Magnetic tape drives have received significant attention for archival data storage owing to its low cost, low power consumption and large storage capacity. With the gradual shift towards cloud storage and more people relying on digital information everyday, the demand for tape drives is expected to increase steadily in the near future. Since tape drives are contact recording systems, pole tip recession (PTR) and mechanical wear of head are amongst the most pertinent issues in developing future high areal density tape drives. PTR creates an undesirable magnetic spacing, resulting in degradation of the signal-to-noise ratio (SNR) during the read/write process. To alleviate the onset of PTR and prevent head wear, various groups have introduced a variety of protective overcoats onto the tape head. However, in general, when tested against commercial tape, ultrathin overcoats with thickness of ∼20 nm or less were unable to protect the head from PTR and mechanical wear when tested for 1-3 million meters [1-4].