Highly tetrahedral amorphous carbon coatings and systems and methods for their production
View Patent ↗The invention provides systems and methods for the deposition of an improved diamond-like carbon material, particularly for the production of magnetic recording media. The diamond-like carbon material of the present invention is highly tetrahedral, that is, it features a large number of the sp 3 carbon-carbon bonds which are found within a diamond crystal lattice. The material is also amorphous, providing a combination of short-range order with long-range disorder, and can be deposited as films which are ultrasmooth and continuous at thicknesses substantially lower than known amorphous carbon coating materials. The carbon protective coatings of the present invention will often be hydrogenated. In a preferred method for depositing of these materials, capacitive coupling forms a highly uniform, selectively energized stream of ions from a dense, inductively ionized plasma. Such inductive ionization is enhanced by a relatively slow moving (or “quasi-static”) magnetic field, which promotes resonant ionization and ion beam homogenization.
1. A coated article comprising:
a glass substrate: an amorphous diamond-like carbon (DLC) coating supported with the glass substrate, wherein the DLC coating includes at least a first tetrahedral amorphous carbon layer having at least about 35% sp 3 bonds and an average density of at least about 2.5 gm/cm 3 ; and
wherein the at least about 35% sp 3 bonds include subplanted carbon bonds.
2. The coated article of claim 1 , wherein the layer provides a plasmon peak of at least about 25 eV.
3. The coated article of claim 2 , wherein the layer provides a plasmon peak of at least about 29 eV.
4. The coated article of claim 3 , wherein the layer provides a plasmon peak of at least about 30 eV.
5. The coated article of claim 1 , wherein the layer provides a G-peak of no more than about 1500 cm −1 .
6. The coated article of claim 1 , wherein the layer provides an Id/Ig Raman ratio of no more than about 1.0.
7. The coated article of claim 6 , wherein the layer provides an Id/Ig Raman ratio of no more than about 0.5.
8. The coated article of claim 7 , wherein the layer provides an Id/Ig Raman ratio of no more than about 0.25.
9. The coated article of claim 1 , wherein the at least about 35% sp 3 bonds includes at least about 35% sp 3 carbon-carbon bonds.
10. The coated article of claim 9 , wherein the at least about 35% sp 3 bonds includes at least about 70% sp 3 carbon-carbon bonds.
11. The coated article of claim 10 , wherein the at least about 35% sp 3 bonds includes at least about 80% sp 3 carbon-carbon bonds.
12. The coated article of claim 1 wherein the DLC coating includes a second layer of tetrahedral amorphous carbon and wherein the first layer is disposed on a first side of the substrate and the second layer is disposed on a second side of the substrate, the second side opposite the first side.
13. The coated article of claim 1 wherein the tetrahedral amorphous carbon layer includes hydrogenated carbon.
14. The coated article of claim 13 wherein the hydrogenated carbon includes more sp 3 carbon-carbon bonds than carbon-hydrogen bonds.
15. The coated article of claim 1 , wherein the DLC coating has a hardness of at least about 50 Gpa.
16. The coated article of claim 1 , wherein the DLC coating has a thickness from about 30 to 1,250 Å.
17. The coated article of claim 1 , wherein the DLC coating has an index of refraction of at least about 2.5.
18. A coated article comprising:
a glass substrate:
a tetrahedral amorphous carbon layer supported with the glass substrate, the carbon layer having a density of at least about 2.4 gm/cm 3 wherein the tetrahedral amorphous carbon layer includes sp 2 and sp 3 carbon-carbon bonds; wherein the tetrahedral amorphous carbon layer has more sp 3 carbon-carbon bonds than sp 2 carbon-carbon bonds; and wherein the sp 3 carbon-carbon bonds are formed by subplantation.
19. The coated article of claim 18 , wherein the tetrahedral amorphous carbon layer includes hydrogenated carbon.
20. The coated article of claim 18 , wherein the tetrahedral amorphous carbon layer includes hydrogenated carbon with carbon-hydrogen bonds and wherein the layer includes more sp 3 carbon-carbon bonds than carbon-hydrogen bonds.
21. The coated article of claim 18 , wherein the tetrahedral amorphous carbon layer has at least about 70% sp 3 carbon-carbon bonds and a thickness from about 30 to 200 Angstroms.
22. A coated article comprising:
a substrate:
a diamond like coating (DLC) layer provided supported with the substrate, the diamond like coating including at least about 15% sp 3 carbon-carbon bonds;
an oxide layer supported with the substrate; and
wherein the oxide layer is adjacent to the diamond like coating.
23. The coated article of claim 22 wherein the oxide layer is included with a magnetic recording medium.
24. The coated article of claim 22 wherein the at least about 15% carbon-carbon bonds include subplanted carbon bonds.
25. The coated article of claim 22 wherein the oxide layer comprises a metal oxide.
26. The coated article of claim 22 wherein the DLC layer is harder than the oxide layer and includes a greater percentage of sp 3 carbon-carbon bonds than the oxide layer.
27. The coated article of claim 22 wherein the oxide layer is in direct contact with the DLC layer.
28. The coated article of claim 22 wherein the DLC coating has been formed with an ion beam deposition process with ions from at least a hydrocarbon gas.
29. The coated article of claim 22 further comprising a second DLC layer supported with the substrate.
30. A coated article comprising:
a glass substrate;
a layer including nickel (Ni) atoms supported with the substrate; and
a layer comprising hydrogenated amorphous diamond-like carbon (DLC) with tetrahedral amorphous carbon, the DLC layer supported with the substrate, the (DLC) layer including sp 3 carbon-carbon bonds; and
wherein the layer with Ni atoms is located between the glass substrate and the DLC layer.
31. The coated article of claim 30 wherein the DLC layer provides a plasmon energy peak of at least about 25 eV.
32. The coated article of claim 30 wherein the DLC layer provides a plasmon energy peak of at least about 30 eV.
33. The coated article of claim 30 wherein the DLC layer includes more sp 3 carbon-carbon bonds than sp 2 carbon-carbon bonds.
34. The coated article of claim 30 wherein the Ni layer is adapted to provide rigidity with the glass substrate.
35. The coated article of claim 30 wherein at least one of the layers comprises Cr atoms.
36. The coated article of claim 30 wherein the DLC layer is hydrogenated and has an average density of at least about 2.5 gm/cm 3 .
37. The coated article of claim 30 further comprising a layer comprising Cr atoms adjacent the layer comprising Ni atoms.
38. The coated article of claim 30 further comprising a second DLC layer comprising tetrahedral amorphous carbon with sp 3 carbon-carbon bonds, the second DLC layer supported with the glass substrate.