# US 8,771,850 B2 · Carbon-deuterium protective overcoat layer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,850 B2 - Document ID: US8771850B2 - Status: Granted - Kind: B2 - Application number: 13/422,868 - Filed: 2012-03-16 - Published: 2013-09-19 - Granted: 2014-07-08 - Earliest claimed: 2012-03-16 - Assignees: Seagate Technology LLC - Applicants: Paul Max Jones; Christopher Loren Platt; Emil John Catoc Esmenda; Lang Nhu Dinh; Junwei Huang; James Dillon Kiely - Inventors: Paul Max Jones; Christopher Loren Platt; Emil John Catoc Esmenda; Lang Nhu Dinh; Junwei Huang; James Dillon Kiely - Web page: https://patentgrep.com/patent/US8771850B2 ## CPC - G11B 5/727: {Inorganic carbon protective coating, e.g. graphite, diamond like carbon or doped carbon} - G11B 5/8408: {protecting the magnetic layer} - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract A substrate having a carbon-deuterium protective overcoat layer, and method for making the same. In some embodiments, the substrate includes a recording structure having a magnetic recording layer. A protective overcoat layer is Formed on the recording structure, the protective overcoat layer composed of carbon-carbon (C—C) and carbon-deuterium (C-D) bonds and having no carbon-hydrogen (C—H) bonds. ## Claims ### Claim 1 An apparatus, comprising: a base substrate; a recording structure in contact with the base substrate comprising a magnetic recording layer; and a protective overcoat layer in contact with the recording structure, the protective overcoat layer composed of carbon-carbon (C—C) and carbon-deuterium (C-D) bonds and having no carbon-hydrogen (C—H) bonds, the protective overcoat layer comprising C2D4 and having a bond strength of at least about 110 kcal/mole. ### Claim 2 (depends on 1) The apparatus of claim 1, further comprising a layer of lubricant in contact with the protective overcoat layer on a side opposite the recording structure. ### Claim 3 (depends on 1) The apparatus of claim 1, characterized as a heat assisted magnetic recording (HAMR) recording medium. ### Claim 4 (depends on 1) The apparatus of claim 1, in which the recording structure further comprises a heat sink layer and a magnetically permeable return layer. ### Claim 5 (depends on 1) The apparatus of claim 1, in which the protective overcoat layer is formed by introducing a feed gas into a deposition chamber having an ionization source, the feed gas having a stoichiometry of CpDq, where p is equal to two and q is equal to four. ### Claim 6 (depends on 1) The apparatus of claim 1, in which the protective overcoat layer is formed using a direct current (DC) arc plasma source. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the protective overcoat layer has a thickness of from about 0.5 nanometers (nm) to about 5.0 nm. ### Claim 8 (depends on 5) The apparatus of claim 5, wherein the protective overcoat layer is further formed by evacuating the chamber prior to introduction of the feed gas so that the chamber is devoid of hydrogen during the deposition of the protective overcoat layer. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the recording structure comprises a ferromagnetic recording layer of a heat assisted magnetic recording (HAMR) data recording medium, and the protective overcoat layer is formed directly on the recording layer. ### Claim 10 (depends on 9) The apparatus of claim 9, in which the recording structure further comprises a heat sink layer and a magnetically permeable return layer, wherein the heat sink layer is disposed between the recording layer and the return layer. ### Claim 11 An apparatus comprising a protective overcoat layer supported by a magnetic recording layer, the protective overcoat layer composed of carbon-carbon (C—C) and carbon-deuterium (C-D) bonds with no carbon-hydrogen (C—H) bonds, the protective overcoat layer comprising C2D4 and having a bond strength of at least about 110 kcal/mole. ### Claim 12 (depends on 11) The apparatus of claim 11, further comprising a substrate which supports the magnetic recording layer. ### Claim 13 (depends on 11) The apparatus of claim 11, further comprising a layer of lubricant in contact with the protective overcoat layer on a side opposite the magnetic recording layer. ### Claim 14 (depends on 11) The apparatus of claim 11, characterized as a heat assisted magnetic recording (HAMR) recording medium. ### Claim 15 (depends on 11) The apparatus of claim 11, further comprising a heat sink layer and a magnetically permeable return layer adjacent the magnetic recording layer on a side opposite the protective overcoat layer. ### Claim 16 (depends on 11) The apparatus of claim 11, in which the protective overcoat layer is formed by introducing a feed gas into a deposition chamber having an ionization source, the feed gas having a stoichiometry of CpDq, where p is equal to two and q is equal to four. ### Claim 17 (depends on 11) The apparatus of claim 11, in which the protective overcoat layer is formed using a direct current (DC) arc plasma source. ### Claim 18 (depends on 11) The apparatus of claim 11, wherein the protective overcoat layer has a thickness of from about 0.5 nanometers (nm) to about 5.0 nm. ### Claim 19 (depends on 11) The apparatus of claim 11, wherein the protective overcoat layer is deposited onto the magnetic recording layer using an ion beam supplied with a current of from about 10 milliamps (mA) to about 100 mA and a voltage of from about 100 electron volts (eV) and about 2,000 eV. ### Claim 20 (depends on 11) The apparatus of claim 11, characterized as a heat assisted magnetic recording (HAMR) recording medium, wherein the protective overcoat layer has an overall thickness of from about 0.5 nanometers (nm) to about 2.5 nm.