Durable ultrathin silicon nitride/carbon bilayer overcoats for magnetic heads: The role of enhanced interfacial bonding

Journal Article · Wed Jan 28 00:00:00 EST 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4906620· OSTI ID:22413016

Yeo, Reuben J.; Dwivedi, Neeraj; Zhang, Lu ^[1]; Zhang, Zheng; Tripathy, S. ^[2]; Lim, Christina Y. H. ^[3]

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1. Institute of Microelectronics (IME), A*STAR (Agency for Science, Technology, and Research), 11 Science Park Road, Singapore Science Park II, Singapore, Singapore 117685 (Singapore)
2. Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology, and Research), 3 Research Link, Singapore, Singapore 117602 (Singapore)
3. Department of Mechanical Engineering, National University of Singapore, Singapore, Singapore 117575 (Singapore)

Pole tip recession (PTR) is one of the major issues faced in magnetic tape storage technology, which causes an increase in the magnetic spacing and hence signal loss during data readback. Despite efforts to reduce the magnetic spacing, PTR, and surface wear on the heads by using protective overcoats, most of them either employ complex fabrication processes and approaches do not provide adequate protection to the head or are too thick (∼10–20 nm), especially for future high density tape storage. In this work, we discuss an approach to reduce the PTR and surface wear at the head by developing an ultrathin ∼7 nm bilayer overcoat of silicon/silicon nitride (Si/SiN{sub x}) and carbon (C), which is totally fabricated by a cost-effective and industrial-friendly magnetron sputtering process. When compared with a monolithic C overcoat of similar thickness, the electrically insulating Si/SiN{sub x}/C bilayer overcoat was found to provide better wear protection for commercial tape heads, as demonstrated by Auger electron spectroscopic analyses after wear tests with commercial tape media. Although the microstructures of carbon in the monolithic and bilayer overcoats were similar, the improved wear durability of the bilayer overcoat was attributed to the creation of extensive interfacial bonding of Si and N with the C overcoat and the alumina-titanium carbide composite head substrate, as predicted by time-of-flight secondary ion mass spectrometry and confirmed by in-depth X-ray photoelectron spectroscopy analyses. This study highlights the pivotal role of enhanced interfaces and interfacial bonding in developing ultrathin yet wear-durable overcoats for tape heads.

• OSTI ID: 22413016
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM OXIDES
CARBON
COMPARATIVE EVALUATIONS
ELECTRONS
HARDNESS
INTERFACES
LAYERS
MAGNETIC TAPES
MASS SPECTROSCOPY
MICROSTRUCTURE
SERVICE LIFE
SILICON
SILICON NITRIDES
SUBSTRATES
SURFACES
TIME-OF-FLIGHT METHOD
TITANIUM CARBIDES
WEAR
WEAR RESISTANCE
X-RAY PHOTOELECTRON SPECTROSCOPY