Go-based alloy films using silicon substrates were investigated for high-density magnetic recording disks. Silicon-disk substrates have several advantages, such as microscopically ultraflat surface roughness in the range of 1 nm or less, which results in a lower than ever flying height, Lithographic fabrication of grooves for servo patterns, minimal outgassing from the substrates, higher substrate temperatures than for aluminum or glass substrates, and higher mechanical strength than for glass substrates. Recent Si substrates are mechanically durable because they have fewer microcracks than previous ones as a result of large improvements in machining processes such as chamfering and holing. In this study, Co85Cr13Ta2/Cr films were deposited by facing targets sputtering on 2.5 in. Si substrates at a substrate temperature of 100 degrees C and an argon gas pressure of 0.2 mTorr. A carbon protective layer and Z-DOL lubricant were applied on top of the magnetic layers. Their magnetic properties and recording characteristics were evaluated and compared with those reported previously at high substrate temperatures in the 350 degrees C range. It was found that, although the H-c at a temperature of 100 degrees C with a Co-Cr-Ta film thickness of 100-400 Angstrom at a background pressure in the 1.5 x 10(-6) Torr range was lower than those in the 350 degrees C range, the frequency response and noise properties obtained when a magnetoresistive head was used were comparable to those of a disk used in current products, which was employed as a reference. These disks, therefore, will be practical for high-density recording. (C) 1997 American Institute of Physics. References: 5
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