ISSN:
1089-7550
Quelle:
AIP Digital Archive
Thema:
Physik
Notizen:
Co–Cr–Ta/Cr bilayered films for longitudinal recording disks were deposited by facing targets sputtering (FTS) on 2.5 in. and ultraflat disk substrates of durable single-crystal silicon at temperature Ts of 100 °C and Ar pressure PAr of 0.2 mTorr. TEM observation of the films revealed ultrafine microstructures, and grain boundaries were unclear. The noise and recording characteristics of those disks were comparable with those of very high-performance disks with Co–Cr–Pt films, with coercivity Hc of 2.4 kOe, employed as a reference, even though the Co–Cr–Ta films exhibited macroscopic Hc of only 800 Oe. In this study, Co85Cr13Ta2/Cr bilayered films with the same composition as the above-mentioned disks were deposited by plasma-enhanced (PEFTS) on 2.5 in. and glass–ceramic substrates with ultraflat surface and tough durability at Ts of 100 °C to obtain better microstructure, signal-to-noise ratio (SNR), and surface flatness, with consequent lower flying height, than those on Si substrates, thus making it possible to fabricate ultrahigh-density recording disks. The PEFTS apparatus has several outstanding advantages such as plasma-free substrates, low background pressure of 5×10−7 Torr, low PAr of 0.1 mTorr, and higher mobility of the adatoms than in conventional FTS because of the proximity of the substrate to the central axis of the targets, indicating uniform plasma distribution, with up to six target units in a vacuum chamber. The film's surface roughness Ra of 0.7 nm and the high mobility of the adatoms result in narrow grain boundaries without pores and inclusions, which were observed by TEM, and better overwrite performance than that of Si substrates and the same SNR as Si substrates, which were measured with a read/write test stand. These results will allow practical application in ultrahigh-density recording systems, including 1 in. microdrives. © 2000 American Institute of Physics.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.372700
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