Microstructure and Properties of Ultra-Thin Amorphous Silicon Nitride Protective Coating

Technical Report · Wed Jun 25 04:00:00 EDT 2003

DOI:https://doi.org/10.2172/813272· OSTI ID:813272

Toney, Michael F ^[1]

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1. SLAC

The effect of N content on the structure and properties of rf reactively sputtered a-SiN{sub x} has been studied by Rutherford backscattering spectrometry (RBS), x-ray reflectivity (XRR), ellipsometry, and nano-indentation. The N content in the film increased with the N{sub 2} concentration in the sputtering gas until the Si{sub 3}N{sub 4} stoichiometry was reached. The hardness of a-SiN, increased with density, which in turn increased with the N content. The maximum hardness of 25 GPa and density of 3.2 g/cm{sup 3} were attained at the stoichiometric Si{sub 3}N{sub 4} composition. With the application of protective overcoat for magnetic disks in mind, thin a-SiN{sub x} films were deposited on CoPtCr media to examine their coverage, pinhole density, and wear resistance. According to x-ray photoelectron spectroscopy (XPS), the minimum thickness of a-SiN{sub x} required to protect the CoPtCr alloy from oxidation was 10 {angstrom}, which was 10 {angstrom} thinner than that of the reference a-CN{sub x}. A statistic model showed the lower coverage limit of a-SiN{sub x} can be attributed to its high density, which corresponds to 93% bulk density of Si{sub 3}N{sub 4}. Compared with 45 {angstrom} a-CN{sub x} coated disks, 15 {angstrom} a-SiN{sub x} coated disks had lower pinhole defect density and superior wear resistance.

• Research Organization: Stanford Linear Accelerator Center, Menlo Park, CA (US)
• Sponsoring Organization: USDOE Office of Science (US)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 813272
• Report Number(s): SLAC-PUB-10008
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BULK DENSITY
CHROMIUM ALLOYS
COBALT ALLOYS
CORROSION PROTECTION
ELLIPSOMETRY
HARDNESS
MAGNETIC DISKS
MICROSTRUCTURE
PLATINUM ALLOYS
PROTECTIVE COATINGS
RUTHERFORD BACKSCATTERING SPECTROSCOPY
SILICON NITRIDES
WEAR RESISTANCE
X-RAY PHOTOELECTRON SPECTROSCOPY