Patents by Inventor John Ko-Jen Chen

John Ko-Jen 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).

  • Patent number: 6013161
    Abstract: A Co--Pt based magnetic alloy which has been doped with a relatively high amount of nitrogen, e.g., at or above 1 at. % is obtained having high coercivity, for example in the range of 1400 Oe or above, and an increased signal-to-noise ratio as compared to the same Co--Pt based alloy which has not been doped with nitrogen. The alloy is vacuum deposited, for example, by sputtering, and the nitrogen may be introduced from the sputtering gas or from the sputtering target. Other low-solubility elements providing the grain uniformity and isolation include: B, P, S, C, Si, As, Se and Te.
    Type: Grant
    Filed: October 28, 1997
    Date of Patent: January 11, 2000
    Assignee: Komag, Incorporated
    Inventors: Tu Chen, Tsutomu Tom Yamashita, John Ko-Jen Chen, Rajiv Yadav Ranjan, Keith Kadokura, Ting Joseph Yuen
  • Patent number: 5908514
    Abstract: A new magnetic alloy exhibits high Hc and Ms while exhibiting excellent corrosion resistance, thereby providing ideal physical properties for high density recording applications. Other parameters of the media, such as SNR, PW50, and S are at least maintained, if not also improved. The alloy contains cobalt and up to 10 at. % Ni, up to 20 at. % Pt, up to 10 at. % Ta, up to 10 at. % Ti, and optionally up to 6 at. % B. The ratio of the tantalum to titanium in the alloy is between 3:1 and 1:3. The alloy is deposited by vacuum deposition (typically sputtering) on a similarly deposited non-magnetic alloy under layer. Nitrogen and/or oxygen may be introduced into the alloy during deposition to improve SNR. Other corrosion-resistant thin film alloys may also be obtained by the inclusion of Ta and Ti.
    Type: Grant
    Filed: October 24, 1996
    Date of Patent: June 1, 1999
    Inventors: Rajiv Yadav Ranjan, Tu Chen, Tsutomu Tom Yamashita, John Ko-Jen Chen
  • Patent number: 5851688
    Abstract: A Co--Pt based magnetic alloy which has been doped with a relatively high amount of nitrogen, e.g., at or above 1 at. % is obtained having high coercivity, for example in the range of 1400 Oe or above, and an increased signal-to-noise ratio as compared to the same Co--Pt based alloy which has not been doped with nitrogen. The alloy is vacuum deposited, for example, by sputtering, and the nitrogen may be introduced from the sputtering gas or from the sputtering target. Other low-solubility elements providing the grain uniformity and isolation include: B, P, S, C, Si, As, Se and Te.
    Type: Grant
    Filed: November 20, 1997
    Date of Patent: December 22, 1998
    Assignee: Komag, Inc.
    Inventors: Tu Chen, Tsutomu Tom Yamashita, John Ko-Jen Chen, Rajiv Yadav Ranjan, Keith Kadokura, Ting Joseph Yuen
  • Patent number: 5658659
    Abstract: Media according to the present invention is comprised of individual magnetic grains as small as 300 .ANG. or smaller in diameter, which are uniformly spaced apart by a distance between 5 and 50 .ANG. by a solid segregant. This media will typically exhibit coercivity and remanent coercivity squareness of at least 0.8 each, a switching field distribution of less than 0.2, and a coercivity of at least 1500 Oe (with a minimum required Pt content), while simultaneously providing the lowest media jitter noise for optimum magnetic performance. The media is deposited at a low partial pressure of water and in the presence of an optimum amount of contributant gas on a doped nucleation layer for grain growth control.
    Type: Grant
    Filed: August 5, 1994
    Date of Patent: August 19, 1997
    Assignee: Komag, Inc.
    Inventors: Tu Chen, Rajiv Yadav Ranjan, Tsutomu Tom Yamashita, Miaogen Lu, Keith Kadokura, John Ko-Jen Chen, Ting Joseph Yuen