Patents by Inventor Qixu David Chen

Qixu David Chen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20080055777
    Abstract: A scratch erasure resistant perpendicular magnetic recording medium comprises a non-magnetic substrate having a surface, and a layer stack formed over the surface and comprising: (i) at least one magnetically hard perpendicular magnetic recording layer; and (ii) at least one low shear modulus layer comprising at least one material having a shear modulus not greater than about 30 GPa. Preferably, the at least one magnetically hard perpendicular magnetic recording layer includes at least a first layer comprised of a magnetic material having a hexagonal close packed (hcp) crystal structure and <0001> preferred basal plane crystallographic orientation with c-axis perpendicular to a surface thereof.
    Type: Application
    Filed: September 6, 2006
    Publication date: March 6, 2008
    Inventors: Shanghsien (Alex) Rou, Qixu (David) Chen, Raj N. Thangaraj, Huan Tang, Xinwei Li, Jing Gui
  • Patent number: 7175925
    Abstract: A perpendicular magnetic recording medium, comprising: (a) a non-magnetic substrate having a surface; and (b) a layer stack formed over the substrate surface, comprising in overlying sequence from the substrate surface: (i) a magnetically soft underlayer; (ii) an interlayer structure for crystallographically orienting a layer of a perpendicular magnetic recording material formed thereon; and (iii) at least one crystallographically oriented magnetically hard perpendicular recording layer; wherein the magnetically soft underlayer is sputter-deposited at a sufficiently large target-to-substrate spacing and at a sufficiently low gas pressure selected to provide the underlayer with a smooth surface having a low average surface roughness Ra below about 0.3 nm, as measured by Atomic Force Microscopy (AFM).
    Type: Grant
    Filed: September 17, 2003
    Date of Patent: February 13, 2007
    Assignee: Seagate Technology LLC
    Inventors: Qixu David Chen, Thomas P. Nolan, Zhong Stella Wu, Samuel Dacke Harkness, IV, Rajiv Yadav Ranjan
  • Patent number: 6936353
    Abstract: Magnetic recording media having a magnetic layer with an easy magnetization axis lying about 45° out of plane of the magnetic layer is disclosed. SMNR from this media could be greatly improved from conventional longitudinal and perpendicular recording, because of an increase in the grain anisotropy that could be effectively written due to the angled recording configuration, resulting also in higher thermal stability, therefore, suitable for higher areal density recording.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: August 30, 2005
    Assignee: Seagate Technology LLC
    Inventors: Zhong Stella Wu, Qixu David Chen, Samuel D. Harkness, IV
  • Publication number: 20040247945
    Abstract: A perpendicular magnetic recording medium, comprising:
    Type: Application
    Filed: September 17, 2003
    Publication date: December 9, 2004
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Qixu David Chen, Thomas P. Nolan, Zhong Stella Wu, Samuel Dacke Harkness, Rajiv Yadav Ranjan
  • Patent number: 6787251
    Abstract: A bi-crystal magnetic recording medium, i.e., medium with Cr(200) and Co(11.0) orientations, having a CrW-containing underlayer in which the W content increases for improved lattice matching with a Co-alloy magnetic layer has high coercivity, high SMNR and high areal recording density.
    Type: Grant
    Filed: August 5, 2002
    Date of Patent: September 7, 2004
    Assignee: Seagate Technology LLC
    Inventors: Zhong Stella Wu, Qixu David Chen, Samuel Dacke Harkness
  • Patent number: 6723374
    Abstract: A magnetic recording media is formed with high in-plane coercivity employing dual magnetic layers. The first magnetic layer is sputter deposited in a chamber employing a shield such that the minimum incident angle of impinging atoms is relatively large, e.g., greater than about 26°. Embodiments of the present invention comprise depositing a NiAl seedlayer, a Cr or Cr alloy underlayer and a first CoCrTa magnetic layer at a thickness less than about 50 Å for inducing the preferred (10.0) crystallographic orientation in the subsequently deposited second magnetic layer, e.g., CoCrPtTa or CoCrPtTaNb having a high Cr content of about 16 to about 21 at. %.
    Type: Grant
    Filed: September 24, 2002
    Date of Patent: April 20, 2004
    Assignee: Seagate Technology LLC
    Inventors: Qixu(David) Chen, Lin Huang, Charles Leu, Rajiv Yadav Ranjan
  • Patent number: 6699588
    Abstract: Sputter-deposited amorphous NiNb films on glass or glass-ceramic substrates have good adhesion with the substrates, and reduce lithium migration significantly. Longitudinal magnetic recording media deposited on oxidized NiNb sealing layers have very good magnetic recording performances and are suitable for high density recording application.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: March 2, 2004
    Assignee: Seagate Technology, Inc.
    Inventors: Qixu (David) Chen, Liji Huang, Charles Leu, Rajiv Yadav Ranjan
  • Patent number: 6562488
    Abstract: A magnetic recording medium on glass or Al substrates with film structures of CrV/NiAl/CrMo/CoCrTa/CoCrPtTaNbB and CrMo/CoCrTa/CoCrPtTaNbB exhibit high coercivity and high signal-to-medium noise ratio. The medium can be used for high-density longitudinal magnetic recording. Embodiments include forming a sub-seed layer on a NiP-plated aluminum substrate, and sequentially depositing a seed layer, an underlayer, an intermediate layer and a magnetic layer on the substrate. The magnetic layer contains at least six elements, including Co, Cr and B.
    Type: Grant
    Filed: February 2, 2000
    Date of Patent: May 13, 2003
    Assignee: Seagate Technology LLC
    Inventors: Qixu (David) Chen, Samuel Dacke Harkness, IV, Zhong (Stella) Wu, Lin Huang, Rajiv Yadav Ranjan, Charles Leu
  • Publication number: 20030039863
    Abstract: A magnetic recording media is formed with high in-plane coercivity employing dual magnetic layers. The first magnetic layer is sputter deposited in a chamber employing a shield such that the minimum incident angle of impinging atoms is relatively large, e.g., greater than about 26°. Embodiments of the present invention comprise depositing a NiAI seedlayer, a Cr or Cr alloy underlayer and a first CoCrTa magnetic layer at a thickness less than about 50Å for inducing the preferred (10.0) crystallographic orientation in the subsequently deposited second magnetic layer, e.g., CoCrPtTa or CoCrPtTaNb having a high Cr content of about 16 to about 21 at.%.
    Type: Application
    Filed: September 24, 2002
    Publication date: February 27, 2003
    Applicant: Seagate Technology LLC.
    Inventors: Qixu (David) Chen, Lin Huang, Charles Leu, Rajiv Yadav Ranjan
  • Patent number: 6461750
    Abstract: A magnetic recording media is formed with high in-plane coercivity employing dual magnetic layers. The first magnetic layer is sputter deposited in a chamber employing a shield such that the minimum incident angle of impinging atoms is relatively large, e.g., greater than about 26°. Embodiments of the present invention comprise depositing a NiAl seedlayer, a Cr or Cr alloy underlayer and a first CoCrTa magnetic layer at a thickness less than about 50Å for inducing the preferred (10.0) crystallographic orientation in the subsequently deposited second magnetic layer, e.g., CoCrPtTa or CoCrPtTaNb having a high Cr content of about 16 to about 21 at. %.
    Type: Grant
    Filed: September 28, 1999
    Date of Patent: October 8, 2002
    Assignee: Seagate Technology, Inc.
    Inventors: Qixu (David) Chen, Lin Huang, Charles Leu, Rajiv Yadav Ranjan
  • Patent number: 6416881
    Abstract: Sputter-deposited amorphous metal oxide films on substrates comprising an aluminum-containing support and a Ni-containing pre-coat reduce Ni ion migration significantly from the substrate onto the top surface of the magnetic recording media. Longitudinal magnetic recording media deposited on metal oxide sealing layers have very good magnetic recording performances and are suitable for high density recording application.
    Type: Grant
    Filed: May 15, 2000
    Date of Patent: July 9, 2002
    Assignee: Seagate Technology LLC
    Inventors: Lin Huang, Liji Huang, Qixu David Chen, Charles Leu, Rajiv Yadav Ranjan
  • Patent number: 6403241
    Abstract: A magnetic recording medium on glass or Al substrates with film structure of NiAl seed layer/CrMo underlayer/CoCrPtB magnetic layer/carbon overcoat, in which the magnetic layer has a substantially (10.0) crystallographic orientation, exhibits high coercivity, high signal-to-medium noise ratio and low transition jitter. The medium can be used for high-density longitudinal magnetic recording. Embodiments include forming a surface oxidized NiAl sub-seed layer on a glass or glass-ceramic substrate, and sequentially depositing a seed layer of NiAl, an underlayer of Cr or Cr-alloy, such as CrMo, and a CoCrPtB magnetic layer.
    Type: Grant
    Filed: February 2, 2000
    Date of Patent: June 11, 2002
    Assignee: Seagate Technology, Inc.
    Inventors: Qixu (David) Chen, Samuel Dacke Harkness, IV, Zhong (Stella) Wu, Lin Huang, Rajiv Yadav Ranjan, Charles Leu
  • Publication number: 20020064690
    Abstract: Sputter-deposited amorphous NiNb films on glass or glass-ceramic substrates have good adhesion with the substrates, and reduce lithium migration significantly. Longitudinal magnetic recording media deposited on oxidized NiNb sealing layers have very good magnetic recording performances and are suitable for high density recording application.
    Type: Application
    Filed: April 27, 2000
    Publication date: May 30, 2002
    Inventors: Qixu David Chen, Liji Huang, Charles Leu, Rajiv Yadav Ranjan
  • Patent number: 6376097
    Abstract: Sputter-deposited TiW film interposed between a magnetic layer and a nitrogen-containing overcoat of a magnetic recording medium significantly reduces the migration of nitrogen from the overcoat to the magnetic layer, thereby improving the magnetic recording performances of the magnetic recording medium.
    Type: Grant
    Filed: August 2, 2000
    Date of Patent: April 23, 2002
    Assignee: Seagate Technology LLC.
    Inventors: Charles Leu, Lin Huang, Qixu David Chen, Rajiv Yadav Ranjan
  • Patent number: 6346339
    Abstract: Magnetic recording media exhibiting enhanced SMNR are formed with an NiAlOx sub-seedlayer for microstructural control of the underlayer to enable deposition and growth of a magnetic layer exhibiting a (10{overscore (1)}0)-predominant crystallographic orientation and small, uniform grain size. Embodiments include completely reactive sputter depositing a NiAlOx sub-seedlayer on a glass-ceramic substrate and sequentially depositing thereon a NiAl seedlayer, a Cr or Cr-alloy underlayer, e.g., CrMo, a Co—Cr magnetic layer and a protective overcoat, e.g., carbon. The resulting magnetic recording media exhibit a high SMNR, high OW, narrow PW50, improved jitter and improved Hr.
    Type: Grant
    Filed: August 23, 1999
    Date of Patent: February 12, 2002
    Assignee: Seagate Technology LLC
    Inventors: Samuel Dacke Harkness, IV, Qixu (David) Chen, Zhong (Stella) Wu, Rajiv Yadav Ranjan
  • Publication number: 20010033460
    Abstract: A disc drive load/unload ramp incorporates a coat of hardened film, the hardened film providing a surface that is more wear resistant and less likely to result in debris formation during normal disc drive use. The hardened surface material, which includes, but is not limited to, DLC, silicon nitrite and titanium carbide, is deposited by sputtering techniques. A disc drive compatible lubricant layer is added to the hardening film to reduce friction. A method of reducing debris formation in a disc drive having a load/unload ramp includes first depositing a hardened film on the load/unload ramp followed by depositing a lubricant layer on the hardened film.
    Type: Application
    Filed: February 5, 2001
    Publication date: October 25, 2001
    Applicant: Seagate Technology LLC
    Inventors: Serge Jacques Fayeulle, Youmin Liu, QiXu (David) Chen, Chung Shih, Nigel Charles Macleod
  • Patent number: 6139981
    Abstract: Adhesion between a deposited seed layer, e.g., a sputter-deposited NiP seed layer, on an alternate substrate, such as a glass, ceramic or glass-ceramic substrate, is significantly enhanced by depositing a chromium or chromium-alloy adhesion enhancement film between the substrate and seed layer. Magnetic recording media comprising a surface-oxidized NiP seed layer and chromium adhesion enhancement film exhibit low media noise and are suitable for high density longitudinal magnetic recording.
    Type: Grant
    Filed: September 14, 1998
    Date of Patent: October 31, 2000
    Assignee: Seagate Technology, Inc.
    Inventors: Elsie Yang Chuang, Phuong Nguyen, Qixu David Chen, Xing Song, Charles Leu, Thanh Thien Ha
  • Patent number: 6117570
    Abstract: High areal density magnetic recording media exhibiting low noise are formed with a surface oxidized NiAl seed layer. Embodiments include forming the surface oxidized NiAl seed layer on a glass or glass-ceramic substrate, and sequentially depositing a Cr or Cr-alloy, such as CrV, an intermediate CoCrTa layer and a CoCrPtTa magnetic layer.
    Type: Grant
    Filed: September 14, 1998
    Date of Patent: September 12, 2000
    Assignee: Seagate Technology, Inc.
    Inventors: Qixu David Chen, Liji Huang, Charles Leu, Rajiv Yadav Ranjan