Magnetic recording disk and sputtering process and apparatus for producing same
AssigneeCyberdisk, Inc.
InventorVirgle L. Hedgcoth
Life of this patent
Estimating the term…
Abstract
The improved memory disk of the present invention comprises a substrate coated with chromium with preferably a layer of cobalt/nickel as the magnetic layer sealed with a protective coating of carbon. As a result of circumferential texturing, a circular anisotropic crystal growth has occurred during the sputtering with a circumferential alignment that provides an improved memory disk having a reduced amplitude modulation, an improved squareness of the hysteresis loop, e.g. lower switching field distribution and a high production relatively low cost production system. As a result, a higher recording linear bit density due to the high coercivity and low switching field distribution can be experienced with the magnetic disk of the present invention.
Claims16
A magnetic thin film recording disk comprising:
- a flat smooth substrate characterized by a physically abraded surface having a uniform series of physical circumferential texturing of hills and valleys prior to any sputtering operation to encourage a circular anisotropic orientation of crystal growth during sputtering, the hill to valley distance being approximately 200 Angstroms;
- a thin film nucleating layer having a thickness within a range of 1000 to 5000 Angstroms disposed on the substrate;
- a thin film magnetic layer disposed on the nucleating layer with a circular anisotropic orientation of crystal growth within the range of 200 to 1500 Angstroms of thickness and reflected from one of cobalt, a cobalt/nickel alloy, a cobalt/chromium alloy and a cobalt/vanadium alloy;
- and
- a thin film protective coatng disposed on the magnetic layer.
A magnetic thin film recording disk comprising:
- a flat smooth substrate characterized by a physically abraded surface having a uniform series of physical circumferential texturing of hills and valleys prior to any sputtering operation to encourage a circular anisotropic orientation of crystal growth during sputtering, the hill to valley distance being no greater than 500 Angstroms;
- a thin film nucleating layer disposed on the substrate;
- a thin film magnetic layer disposed on the nucleating layer with a circular anisotropic orientation of crystal growth within the range of 200 to 1500 Angstroms of thickness;
- and
- a thin film protective coating disposed on the magnetic layer.
In a magnetic thin film recording disk, the improvement comprising:
- a flat smooth substrate characterized by a physically abraded surface having a uniform series of physical circumferential texturing of hills and valleys prior to any sputtering operation to encourage a circular anisotropic orientation of crystal growth during sputtering, the hill to valley distance being no greater than 500 Angstroms;
- a thin film nucleating layer havng a thickness within the range of 1000 to 5000 Angstroms disposed on the substrate;
- and
- a thin film magnetic layer disposed on the nucleating layer with a circular anisotropic orientation of crystal growth within the range of 200 to 1500 Angstroms of thickness.
Dependencies are inferred from the claim text.