Thin film recording and method of making

Abstract

A thin film of magnetic recording material is sputter deposited over a base layer of gold and tantalum on a polished substrate. A protective layer of gold and tantalum is deposited overlaying the magnetic recording film. A solid lubricant layer such as carbon, preferably in the form of graphite, gold, silver, tin, molybdenum disulfide, and tungsten disulfide is sputter deposited or ion plated over the protective layer to reduce wear. The recording contacting portion of the recording head is similarly coated with a solid lubricant material. Other suitable protective materials include tantalum, niobium, tungsten and nitrides and carbides of such metals. In a preferred method for making such recording members, the layers are successively sputter deposited in an evacuated sputter chamber, whereby the recording layers and protective coatings are formed in a continuous process requiring only one pump down.

What is claimed is: 
     
       1. In a magnetic recording medium, a substrate member, a film of magnetic recording material overlaying said substrate, and a protective layer of gold and tantalum overlaying said film of magnetic recording material. 
     
     
       2. The recording medium of claim 1 including a lubricant layer of carbon overlaying said protective layer. 
     
     
       3. The recording medium of claim 2 wherein said layer of carbon is in the form of graphite. 
     
     
       4. The recording medium of claim 2 wherein said layer of carbon is bonded to the adjacent sublayer on said substrate member. 
     
     
       5. The recording medium of claim 1 wherein said substrate is made of a material selected from the class consisting of ceramic, aluminum, and glass, said substrate having a polished surface, and wherein said magnetic film is deposited to a thickness between 2 and 15 microinches overlaying said polished surface of said substrate. 
     
     
       6. In a method for making a magnetic recording medium, depositing a film of magnetic recording material onto a substrate member, and depositing a layer of gold and tantalum over said film of magnetic recording material. 
     
     
       7. The method of claim 6 wherein said layer of gold and tantalum is deposited by sputtering gold and tantalum over said magnetic film in a gaseous atmosphere at subatmospheric pressure. 
     
     
       8. The method of claim 6 including the step of, depositing a layer of carbon over said layer of gold and tantalum. 
     
     
       9. The method of claim 8 wherein said layer of carbon is deposited by sputtering carbon over said gold and tantalum in a gaseous atmosphere at subatmospheric pressure. 
     
     
       10. The method of claim 9 wherein said carbon is sputtered from a graphite target by ion bombardment to form a graphite layer of carbon over said gold and tantalum. 
     
     
       11. The method of claim 8 wherein said layer of carbon is deposited by ion plating carbon over said gold and tantalum layer from a glow discharge in a gaseous atmosphere at subatmospheric pressure. 
     
     
       12. In a method for making a magnetic recording medium the steps of, depositing at subatmospheric pressure a base layer of a metal selected from the group consisting of molybdenum, titanium, chromium, niobium, tantalum, vanadium, and tungsten overlaying a substrate member, said substrate member comprising a material selected from the class consisting of ceramic, aluminum and glass, depositing at subatmospheric pressure a film of magnetic recording material over said first layer, and depositing at subatmospheric pressure a protective layer of material selected from the class consisting of niobium, tantalum, and tungsten over said magnetic recording film. 
     
     
       13. The method of claim 12 including the step of forming a solid lubricating layer selected from the class consisting of carbon, graphite, molybdenum disulfide, tin, gold, silver, and tungsten disulfide over said protective layer. 
     
     
       14. The method of claim 13 wherein said base, magnetic, protective, and lubricating layers are all deposited by sputtering said respective materials onto said substrate from respective targets in a gaseous atmosphere at subatmospheric pressure. 
     
     
       15. The method of claim 12 wherein said base, magnetic, and protective layers are all deposited by sputtering said respective materials onto said substrate from respective targets in a gaseous atmosphere at subatmospheric pressure. 
     
     
       16. The method of claim 12 wherein said step of depositing a protective layer comprises the step of depositing a layer of gold and tantalum over said magnetic recording layer with the proportion of gold in the layer increasing in a direction taken away from the direction of the magnetic recording layer, whereby the proportion of gold increases at the outer surface to form a lubricating coating over a wear resistant and corrosion resistant protective layer. 
     
     
       17. The method of claim 12 wherein each of said base and protective layers comprises a layer of gold and tantalum. 
     
     
       18. In a method for making a recording medium, the steps of, growing a film of recording material onto a substrate member, and growing a protective layer of material over said film of recording material, such protective layer being selected from the class consisting of niobium, tantalum, tungsten, refractory carbides and refractory nitrides. 
     
     
       19. The method of claim 18 including the step of anodizing the protective layer. 
     
     
       20. The method of claim 18 wherein the step of growing the protective layer comprises the step of sputter depositing said protective layer. 
     
     
       21. The product made by the method of claim 18. 
     
     
       22. The method of claim 18 wherein said protective layer is selected from the group consisting of silicon nitride and silicon carbide. .Iadd. 
     
     
       23.  In a method for protecting a magnetic recording disc of the type having a disc-shaped substrate coated with a continuous, non-particulate film of magnetic recording medium, the steps of: exciting a gaseous atmosphere at subatmospheric pressure with an electrical discharge;   sputtering carbon within said excited gaseous atmosphere at subatmospheric pressure; and   depositing a film of the sputtered carbon onto the coated substrate and tightly adhering the sputtered carbon film to the coated substrate in overlaying relationship with the film of magnetic recording medium to form a tightly adherent wear-resistant carbon film on the coated substrate for causing the magnetic recording disc to be wear-resistant. .Iaddend.   
     
     
        .Iadd.24. The product made by the method of claim 23. .Iaddend. .Iadd.25. The method of claim 23 wherein said wear resistant film of carbon is deposited by sputtering carbon from a carbon target, disposed within said gaseous atmosphere at subatmospheric pressure, onto the substrate in overlaying relationship with said film of magnetic recording medium. .Iaddend. .Iadd.26. The method of claim 23 including the step of adhering the carbon film directly onto a layer of a carbide former material on the disc. .Iaddend. .Iadd.27. In a method for protecting a magnetic recording disc of the type having a disc-shaped substrate coated with a continuous non-particulate film of magnetic recording medium, the steps of: exciting a gaseous atmosphere at subatmospheric pressure with an electrical discharge; and   ionizing carbon within said excited gaseous atmosphere at subatmospheric pressure; and   plating a film of the ionized carbon onto the coated substrate in overlaying relationship with the film of magnetic recording medium to form a tightly adherent wear-resistant carbon layer on the coated substrate for causing the resultant magnetic recording disc to be wear-resistant.   
     
     
        .Iaddend. .Iadd.28.  The product made by the method of claim 27. .Iaddend. .Iadd.29. In a method for making a magnetic recording disc of the type having a disc-shaped, polished, aluminum substrate, the steps of: sputter depositing a film of chromium overlaying the substrate,   sputter depositing a film of cobalt alloy as the magnetic recording layer and adhering the cobalt film directly to said chromium film; and   sputter depositing a tightly adherent wear resistant film of carbon onto the substrate in overlaying relationship with the cobalt alloy film for causing the resultant magnetic recording disc to be wear resistant. .Iaddend.