Patents by Inventor James K. Howard

James K. Howard 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: 5149409
    Abstract: In the fabrication of thi film cobalt alloy magnetic recording disks by sputter-deposition, the coercivity of the disks can be selectively varied by introducing a predetermined amount of hydrocarbon gas, such as methane, into the argon-based sputtering atmosphere. The flow rate of the hydrocarbon gas into the sputtering chamber is directly related to the coercivity of the resulting disks. This permits the coercivity of the disks to be controlled without the necessity of changing the composition of the cobalt alloy sputtering targets, and without the necessity of changing the thickness of an underlying between the disk substrate and the magnetic layer. The use of hydrocarbon gas in the reactive sputtering of the cobalt alloy magnetic layer in the disks does not affect the intrinsic media noise of the disks, thus allowing for the manufacturing of disks with high signal-to-noise ratio (SNR) of the readback signal.
    Type: Grant
    Filed: January 11, 1991
    Date of Patent: September 22, 1992
    Assignee: International Business Machines Corporation
    Inventors: Richard H. Ahlert, James K. Howard, Steven E. Lambert
  • Patent number: 5066552
    Abstract: An improved CoPt alloy magnetic recording disk for horizontal recording has a magnetic recording layer which includes oxygen, the oxygen being present preferably in the range of approximately 5 to 30 atomic percent. The resulting disk structure has substantially decreased intrinsic media noise at high linear recording density.
    Type: Grant
    Filed: August 16, 1989
    Date of Patent: November 19, 1991
    Assignee: International Business Machines Corporation
    Inventors: James K. Howard, Randall G. Simmons, Tadashi Yogi
  • Patent number: 5062938
    Abstract: A cobalt alloy disk for horizontal magnetic recording has both high coercivity and low noise at high recording density. The magnetic layer in the disk contains, in addition to the cobalt alloy material, an oxide of one or more "impurity" elements which have both a relatively low solubility in cobalt and a high affinity for oxygen. Such elements include yttrium (Y), silicon (Si), the rare earth elements, hafnium (Hf), germanium (Ge), tin (Sn) and zirconium (Zr). The disk may be formed by co-sputtering the cobalt alloy material and the impurity element(s), and thereafter oxidizing the impurity element(s). The oxidation may occur by heating the disk while the magnetic layer is exposed to oxygen or air, or by exposure of the magnetic layer to an argon-oxygen plasma.
    Type: Grant
    Filed: January 16, 1990
    Date of Patent: November 5, 1991
    Assignee: International Business Machines Corporation
    Inventor: James K. Howard
  • Patent number: 5051288
    Abstract: An improved CoPt based or CoNi based alloy magnetic recording disk for horizontal recording has a magnetic recording layer which is a laminated structure of relatively thin magnetic alloy films separated by relatively thin non-magnetic spacer films. The resulting laminated disk structure has substantially decreased intrinsic media noise at high linear recording densities.
    Type: Grant
    Filed: March 16, 1989
    Date of Patent: September 24, 1991
    Assignee: International Business Machines Corporation
    Inventors: Richard H. Ahlert, James K. Howard, Steven E. Lambert, Ian L. Sanders
  • Patent number: 5030494
    Abstract: A thin film metal alloy magnetic recording disk has an improved protective overcoat which is both wear resistant and which creates a low level of stiction in a rigid disk file. In a preferred embodiment the overcoat is a film of essentially amorphous carbon or hydrogen-containing carbon with relatively small amounts of additives of iron (Fe), tungsten (W) or tungsten-carbide (WC). The structure of the overcoat is a relatively smooth planar carbon surface with discrete clusters of the additives which project slightly above the smooth carbon surface. The specific additives to the carbon overcoat improve the wear resistance of the disk and permit the sliders to contact the disks in contact start/stop (CSS) operation without damage to any of the disk file components.
    Type: Grant
    Filed: January 26, 1989
    Date of Patent: July 9, 1991
    Assignee: International Business Machines Corporation
    Inventors: Richard H. Ahlert, James K. Howard, Kwang K. Kim, Ian L. Sanders, Anthony W. Wu
  • Patent number: 4940511
    Abstract: A magnetoresistive (MR) read transducer comprising a thin film MR layer formed of ferromagnetic material and a nonmagnetic thin film spacer layer in contact with the MR layer. The spacer layer comprises a material selected from the group consisting of nichrome and nichrome with chromium oxide. A thin film of soft magnetic material is deposited in contact with the spacer layer so that a transverse bias is produced in at least a part of the MR layer. A feature of the invention is that the resistivity of the spacer layer can be chosen by selecting the ratio of nichrome to chromium oxide in the spacer layer. In a specific embodiment the spacer layer extends over only the central region of the MR layer. In case the MR layer is a nickel based alloy, a wet chemical etching process using an etchant comprising an aqueous solution of ceric ammonium nitrate and acetic acid can be used to pattern the spacer layer.
    Type: Grant
    Filed: May 22, 1989
    Date of Patent: July 10, 1990
    Assignee: International Business Machines Corporation
    Inventors: Robert E. Fontana, Jr., James K. Howard, James H. Lee, Haralambos Lefakis
  • Patent number: 4914538
    Abstract: A magnetoresistive sensor having spaced electrically conductive lead structures comprising a thin film of tungsten having a thin film overlayer, or, alternatively a thin film underlayer and a thin film overlayer, with both the thin film underlayer and the thin film overlayer formed of a material taken from the groups consisting of Ti, Ta, Cr, Zr, Hf, and TiW.
    Type: Grant
    Filed: August 18, 1988
    Date of Patent: April 3, 1990
    Assignee: International Business Machines Corporation
    Inventors: James K. Howard, Hung-Chang W. Huang, Cherngye Hwang
  • Patent number: 4879619
    Abstract: A magnetoresistive (MR) read transducer comprising a thin film MR layer formed of ferromagnetic material and a nonmagnetic thin film spacer layer in contact with the MR layer. The spacer layer comprises a material selected from the group consisting of nichrome and nichrome with chromium oxide. A thin film of soft magnetic material is deposited in contact with the spacer layer so that a transverse bias is produced in at least a part of the MR layer. A feature of the invention is that the resistivity of the spacer layer can be chosen by selected the ration of nichrome to chromium oxide in the spacer layer. In a specific embodiment the spacer layer extends over only the central region of the MR layer. In case the MR layer is a nickel based alloy, a wet chemical etching process using an etchant comprising an aqueous solution of ceric ammonium nitrate and acetic acid can be used pattern the spacer layer.
    Type: Grant
    Filed: March 28, 1988
    Date of Patent: November 7, 1989
    Assignee: International Business Machines Corporation
    Inventors: Robert E. Fontana, Jr., James K. Howard, James H. Lee, Haralambos Lefakis
  • Patent number: 4825325
    Abstract: A magnetoresistive (MR) sensor which is provided with longitudinal bias by means of exchange coupling between the ferromagnetic MR layer (NiFe) and an ultrathin layer of an antiferromagnetic material (FeMn) with a thickness within the range of about 25 to 200 angstroms. The exchange structure is capped by a protective film to prevent oxidation damage to the exchange structure during subsequent thermal cycling. The capping layer is a dielectric or metal oxide (cermet) film such as Cr.sub.2 O.sub.3, Al.sub.2 O.sub.3, Cr - SiO or Si O.sub.2. Alternatively, the capping layer can be a laminated FeMn-Lx film where Lx is taken from the group consisting of Cr.sub.2 O.sub.3, Al.sub.2 O.sub.3, and Si O.sub.2.
    Type: Grant
    Filed: October 30, 1987
    Date of Patent: April 25, 1989
    Assignee: International Business Machines Corporation
    Inventor: James K. Howard
  • Patent number: 4809109
    Abstract: An improved magnetoresistive (MR) read transducer in which a layered structure comprising an antiferromagnetic layer in direct contact with an MR layer is subjected to a thermal annealing process by heating the structure to a temperature within a chosen range for a chosen time so that a new ternary antiferromagnetic alloy is formed by diffusion. The ternary antiferromagnetic alloy has a high value of exchange bias which is less temperature sensitive. In a specific embodiment in which the MR layer is NiFe and the antiferromagnetic layer is FeMn, the ternary alloy formed by heating the structure to a temperature within the range of 260.degree. C. to 350.degree. C. for 50 to 20 hours has a room temperature exchange bias field with NiFe of about 50 Oersted and an ordering temperature which exceeds 300.degree. C.
    Type: Grant
    Filed: March 25, 1988
    Date of Patent: February 28, 1989
    Assignee: International Business Machines Corporation
    Inventors: James K. Howard, Michael F. Toney, Ching H. Tsang
  • Patent number: 4789598
    Abstract: An improved thin film metal alloy media for horizontal magnetic recording has a magnetic layer of an alloy comprising cobalt, platinum and chromium, where the chromium concentration in the alloy is greater than 17 at.%. The media exhibits unexpectedly high signal-to-noise ratio (SNR) and minimal time jitter, thereby resulting in a media which is capable for use at high linear recording density. The media also exhibits excellent corrosion resistance because of the chromium present in the alloy, thereby eliminating the need for a barrier layer between the magnetic layer and the protective overcoat.
    Type: Grant
    Filed: January 20, 1987
    Date of Patent: December 6, 1988
    Assignee: International Business Machines Corporation
    Inventors: James K. Howard, Run-Han Wang
  • Patent number: 4782413
    Abstract: An improved thin film magnetoresistive (MR) sensor uses an iron-manganese (FeMn) alloy, with the alpha (body-centered-cubic) phase of FeMn present in the alloy, as an antiferromagnetic layer. The presence of alpha FeMn improves the longitudinal exchange bias in the ferromagnetic MR layer, especially when the amount of alpha FeMn exceeds the amount of gamma (face-centered-cubic) FeMn in the FeMn layer.
    Type: Grant
    Filed: April 28, 1987
    Date of Patent: November 1, 1988
    Assignee: International Business Machines Corporation
    Inventors: James K. Howard, Ting C. Huang
  • Patent number: 4778582
    Abstract: A thin film metal alloy magnetic recording disk is manufactured by sputter deposition in an atmosphere consisting essentially of argon and hydrogen. A thin cobalt-based alloy magnetic film and a hydrogenated carbon overcoat are both formed in the same sputtering atmosphere by successive activation of a cobalt-based alloy target and a carbon target. The hydrogen present in the sputtering atmosphere has no adverse effect on the magnetic properties of the disk.
    Type: Grant
    Filed: June 2, 1987
    Date of Patent: October 18, 1988
    Assignee: International Business Machines Corporation
    Inventor: James K. Howard
  • Patent number: 4755897
    Abstract: An improved thin film magnetoresistive (MR) sensor uses an alloy comprising Fe, Mn and Cr as an antiferromagnetic layer to provide a longitudinal exchange bias in the ferromagnetic MR layer. Sufficient exchange biasing is provided and the FeMnCr layer exhibits excellent corrosion resistance.
    Type: Grant
    Filed: April 28, 1987
    Date of Patent: July 5, 1988
    Assignee: International Business Machines Corporation
    Inventor: James K. Howard
  • Patent number: 4749628
    Abstract: A vertical magnetic recording medium is formed of multiple layers, each layer comprising a cobalt-platinum (CoPt) magnetic film formed on a hexagonal-close-packed (HCP) necleating film. The thickness of each CoPt film in each layer is sufficiently thin to assure that the film has perpendicular magnetic anisotropy. The magnetic properties of the multilayered magnetic film structure can be varied by varying the thickness of the individual films and the number of layers.
    Type: Grant
    Filed: April 29, 1986
    Date of Patent: June 7, 1988
    Assignee: International Business Machines Corporation
    Inventors: Richard H. Ahlert, James K. Howard, Grace S. Lim
  • Patent number: 4657824
    Abstract: A vertical magnetic recording media has a ternary alloy magnetic layer deposited on an intermetallic compound nucleating layer. In one example the intermetallic phase of cobalt and tungsten, which occurs at a discrete stoichiometric ratio of 3 to 1, i.e. Co.sub.3 W, forms a nucleating layer deposited on the media substrate. A magntic layer of (CoCr).sub.90 W.sub.10 is formed on the nucleating layer. Both the nucleating layer and the magnetic layer have a hexagonal crystalline structure with hexagonal cell constants which are related by an integral multiple. The film structure has minimal C-axis dispersion and an excellent ratio of perpendicular to horizontal coercivities.
    Type: Grant
    Filed: October 28, 1985
    Date of Patent: April 14, 1987
    Assignee: International Business Machines Corporation
    Inventor: James K. Howard
  • Patent number: 4654276
    Abstract: An improved cobalt-platinum (CoPt) thin film metal alloy media for horizontal magnetic recording has a coercivity substantially greater than prior CoPt thin film metal alloy media. A tungsten underlayer between the substrate and the CoPt magnetic layer improves the coercivity above that of media wiht conventional underlayers, such as chromium. The coercivity of the CoPt layer can be increased even further if the CoPt film is deposited in such a manner as to form an intermetallic compound of Co.sub.3 W in the interface region between the tungsten underlayer and the CoPt magnetic layer. The tungsten underlayer also improves the magnetic properties of the media when the magnetic layer is an alloy of cobalt-platinum-chromium (CoPtCr).
    Type: Grant
    Filed: April 29, 1986
    Date of Patent: March 31, 1987
    Assignee: International Business Machines Corporation
    Inventors: Richard H. Ahlert, James K. Howard, Grace S. Lim
  • Patent number: 4652499
    Abstract: An improved cobalt-platinum (CoPt) thin film metal alloy media for horizontal magnetic recording has a squareness greater than prior CoPt thin film metal alloy media. An underlayer of a body-centered-cubic (BCC) chromium-based alloy with a lattice cell constant greater than chromium (Cr), such as chromium-vanadium (CrV), is formed between the substate and the CoPt magnetic layer. The underlayer also improves the magnetic properties of the media when the magnetic layer is an alloy of cobalt-platinum-chromium (CoPtCr).
    Type: Grant
    Filed: April 29, 1986
    Date of Patent: March 24, 1987
    Assignee: International Business Machines
    Inventor: James K. Howard
  • Patent number: 4632883
    Abstract: A thin film alloy disk for vertical magnetic recording has a cobalt-chromium-tantalum (CoCrTa) magnetic layer with perpendicular magnetic anisotropy deposited on an underlayer of beta-tantalum (.beta.-Ta). The .beta.-Ta layer is deposited on a suitable substrate, such as silicon, which is compatible with the formation of the beta phase of tantalum. The highly preferred orientation of the .beta.-Ta film on the substrate and the incorporation of Ta in the magnetic film results in the magnetic film having improved perpendicular magnetic anisotropy, high perpendicular coercivity and low horizontal coercivity. A nickel-iron (NiFe) layer may be deposited between the substrate and the .beta.-Ta underlayer to provide a magnetic flux return path.
    Type: Grant
    Filed: April 22, 1985
    Date of Patent: December 30, 1986
    Assignee: International Business Machines Corporation
    Inventors: James K. Howard, Mohammad T. Moshref
  • Patent number: 4488262
    Abstract: An electrically programmable read only memory assembly having cells arranged at the intersections of bit lines (BL1) and word lines (WL1, WL2), wherein each cell is formed of a bipolar transistor provided with a base region (70) and an emitter region (71) covered with a dielectric layer (2) made of an oxide or titanate of a transition metal. The cell in this condition represents a binary 0 information bit. The application of an appropriate voltage of approximately 4 volts to the pads of this cell through its corresponding bit line (BL1) and word line (WL2) causes the dielectric layer to break down and places the bit line in ohmic contact with the emitter, which sets the cell in its second condition representing a binary "1" information bit.
    Type: Grant
    Filed: June 17, 1982
    Date of Patent: December 11, 1984
    Assignee: International Business Machines Corporation
    Inventors: Dominique Basire, Arup Bhattacharyya, James K. Howard, Pierre Mollier