Recording characteristics and magnetic grains of rigid disks using siliconsubstrates deposited by facing targets sputtering

Co85Cr13Ta2/Cr bilayered films were deposited by facing targets sputtering (FTS) on 2.5 " durable single-crystal silicon disk substrates at temperatur e of 100 degrees C and Ar pressure of 0.2 mTorr. Their microstructure, magn etic properties, and recording characteristics were investigated to determi ne their potential for use in high-density recording disks. In this study, it was found that, although the coercivity H-c of a Co-Cr-Ta film with thic kness of 100 Angstrom was approximately 800 Oe, the linear-density response up to 92 kFRPI at linear velocity of 15 m/s, the noise properties, and the overwrite performance obtained when a magnetoresistive head was used were comparable to those of the disks with H-c of 2.4 kOe in current products, w hich were employed as a reference. TEM images were observed to investigate what sort of magnetic grains exist in the film and why the recording charac teristics, noise properties, and overwrite performance were comparable. The grain boundaries were unclear, and looked like amorphous structures, These were most likely caused by film deposition without plasma damage by means of FTS on single-crystal Si substrates with ultra-flat surface appearance a nd high thermal conductivity, and free from defects such as pores and inclu sions. Owing to these characteristics, sputtered atoms would conform to the uniform Si surface, giving uniform films. (C) 1999 Published by Elsevier S cience B.V. All rights reserved.