Patents by Inventor Cherng Chyi Han

Cherng Chyi Han 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: 7978431
    Abstract: A perpendicular magnetic recording (PMR) head is fabricated with a pole tip shielded laterally by a separated pair of bottom side shields and shielded from above by an upper shield. The bottom side shields surround a lower portion of the pole tip while the upper portion of the pole tip is surrounded by non-magnetic layers. The bottom shields and the non-magnetic layer form wedge-shaped trench in which the pole tip is formed by a self-aligned plating process. The wedge shape is formed by a RIE process using specific gases applied through a masking layer formed of material that has a slower etch rate than the non-magnetic material or the shield material. A masking layer of Ta, Ru/Ta, TaN or Ti, formed on a non-magnetic layer of alumina that is formed on a shield layer of NiFe and using RIE gases of CH3OH, CO or NH3 or their combinations, produces the desired result. A write gap layer and an upper shield is then formed above the side shields and pole.
    Type: Grant
    Filed: May 31, 2007
    Date of Patent: July 12, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Min Li, Fenglin Liu, Lijie Guan
  • Patent number: 7978440
    Abstract: Improved CPP GMR devices have been fabricated by replacing the conventional seed layer (typically Ta) with a bilayer of NiCr on Ta, said seed being deposited on the NiFe layer that constitutes a magnetic shield. Additional improvement was also obtained by replacing the conventional non-magnetic spacer layer of copper with a sandwich structure of two copper layers with an NOL (nano-oxide layer) between them. A process for manufacturing the devices is also described.
    Type: Grant
    Filed: January 9, 2008
    Date of Patent: July 12, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Min Li, Cheng T. Horng, Cherng Chyi Han, Yue Liu, Yu-Hsia Chen, Ru-Ying Tong
  • Publication number: 20110146060
    Abstract: A perpendicular magnetic recording (PMR) head is fabricated with a pole tip shielded laterally by a separated pair of side shields and shielded from above by an upper shield. The side shields are formed by a RIE process using specific gases applied to a shield layer through a masking layer formed of material that has a slower etch rate than the shield material. A masking layer of Ta, Ru/Ta, TaN or Ti, formed on a shield layer of NiFe and using RIE gases of CH3OH, CO or NH3 or their combinations, produces the desired result. The differential in etch rates maintains the opening dimension within the mask and allows the formation of a wedge-shaped trench within the shield layer that separates the layer into two shields. The pole tip is then plated within the trench and, being aligned by the trench, acquires the wedge-shaped cross-section of the trench. An upper shield is then formed above the side shields and pole.
    Type: Application
    Filed: February 28, 2011
    Publication date: June 23, 2011
    Inventors: Cherng-Chyi Han, Min Li, Fenglin Liu, Jiun-Ting Lee
  • Publication number: 20110097601
    Abstract: A perpendicular magnetic recording (PMR) head is fabricated with a main pole shielded laterally by a pair of side shields, shielded above by a trailing shield and shielded optionally below by a leading shield. The shields and the seed layers on which they are formed are formed of materials having substantially the same physical characteristics including the same material composition, the same hardness, the same response to processes such as ion beam etching (IBE), chemical mechanical polishing (CMP), mechanical lapping, such as the slider ABS lapping, the same coefficient of thermal expansion (CTE) as well as the same Bs. Optionally, the trailing shield may be formed on a high Bs seed layer to provide the write head with improved down-track performance.
    Type: Application
    Filed: October 26, 2009
    Publication date: April 28, 2011
    Inventors: Zhigang Bai, Yan Wu, Moris Dovek, Cherng Chyi Han
  • Patent number: 7898773
    Abstract: A perpendicular magnetic recording (PMR) head is fabricated with a pole tip shielded laterally by a separated pair of side shields and shielded from above by an upper shield. The side shields are formed by a RIE process using specific gases applied to a shield layer through a masking layer formed of material that has a slower etch rate than the shield material. A masking layer of Ta, Ru/Ta, TaN or Ti, formed on a shield layer of NiFe and using RIE gases of CH3OH, CO or NH3 or their combinations, produces the desired result. The differential in etch rates maintains the opening dimension within the mask and allows the formation of a wedge-shaped trench within the shield layer that separates the layer into two shields. The pole tip is then plated within the trench and, being aligned by the trench, acquires the wedge-shaped cross-section of the trench. An upper shield is then formed above the side shields and pole.
    Type: Grant
    Filed: February 2, 2006
    Date of Patent: March 1, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Min Li, Fenglin Liu, Jiun-Ting Lee
  • Publication number: 20100301007
    Abstract: A magnetic head includes a pole layer, first and second side shields, and an encasing layer having first to third grooves that accommodate the pole layer and the first and second side shields. A manufacturing method for the magnetic head includes the step of forming the first to third grooves in a nonmagnetic layer by using an etching mask layer having first to third openings. This step includes the steps of forming the first groove by etching the nonmagnetic layer using the first opening, with the second and third openings covered with a first mask; and forming the second and third grooves by etching the nonmagnetic layer using the second and third openings, with the first opening covered with a second mask.
    Type: Application
    Filed: June 1, 2009
    Publication date: December 2, 2010
    Applicant: HEADWAY TECHNOLOGIES, INC.
    Inventors: Kazuo Ishizaki, Yoshitaka Sasaki, Hironori Araki, Hiroyuki Ito, Shigeki Tanemura, Cherng-Chyi Han
  • Patent number: 7773341
    Abstract: A laminated main pole layer is disclosed in which a non-AFC scheme is used to break the magnetic coupling between adjacent high moment layers and reduce remanence in a hard axis direction while maintaining a high magnetic moment and achieving low values for Hch, Hce, and Hk. An amorphous material layer with a thickness of 3 to 20 Angstroms and made of an oxide, nitride, or oxynitride of one or more of Hf, Zr, Ta, Al, Mg, Zn, or Si is inserted between adjacent high moment stacks. The laminated structure also includes an alignment layer below each high moment layer within each stack. In one embodiment, a Ru coupling layer is inserted between two high moment layers in each stack to introduce an AFC scheme. An uppermost Ru layer is used as a CMP stop layer. A post annealing process may be employed to further reduce the anisotropy field (Hk).
    Type: Grant
    Filed: July 3, 2007
    Date of Patent: August 10, 2010
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Zheng, Min Li, Chen-Jung Chien, Cherng-Chyi Han
  • Patent number: 7751146
    Abstract: Aggressive (i.e. tight tolerance) stitching offers several advantages for magnetic write heads but at the cost of some losses during pole trimming. This problem has been overcome by replacing the alumina filler layer, that is used to protect the stitched pole during trimming, with a layer of electro-plated material. Because of the superior step coverage associated with the plating method of deposition, pole trimming can then proceed without the introduction of stresses to the stitched pole while it is being trimmed.
    Type: Grant
    Filed: July 26, 2007
    Date of Patent: July 6, 2010
    Assignee: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Mao-Min Chen, Laurie Lauchlan, Lei Zhang
  • Patent number: 7701666
    Abstract: A perpendicular magnetic recording (PMR) head with single or double coil layers has a small write shield stitched onto a main write shield. The stitched shield allows the main write pole to produce a vertical write field with sharp vertical gradients that is reduced on both sides of the write pole so that adjacent track erasures are eliminated. From a fabrication point of view, both the main pole and the stitched shield are defined and formed using a single photolithographic process, a trim mask and CMP lapping process so that the main shield can be stitched onto a self-aligned main pole and stitched shield.
    Type: Grant
    Filed: December 11, 2007
    Date of Patent: April 20, 2010
    Assignee: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Kenichi Takano
  • Publication number: 20100061016
    Abstract: A non-conformal integrated side shield structure is disclosed for a PMR write head wherein the sidewalls of the side shield are not parallel to the pole tip sidewalls. Thus, the side gap distance between the leading pole tip edge and side shield is different than the side gap distance between the trailing pole tip edge and side shield. As a result, there is a reduced side fringing field and improved overwrite performance. The side gap distance is constant with increasing distance from the ABS along the main pole layer. A fabrication method is provided where the trailing shield and side shield are formed in the same step to afford a self-aligned shield structure. Adjacent track erasure induced by flux choking at the side shield and trailing shield interface can be eliminated by this design. The invention encompasses a tapered main pole layer in a narrow pole tip section.
    Type: Application
    Filed: September 5, 2008
    Publication date: March 11, 2010
    Inventors: Cherng-Chyi Han, Feiyue Li, Shiwen Huang, Jiun-Ting Lee, Yoshitaka Sasaki
  • Patent number: 7657992
    Abstract: A method of making a perpendicular magnetic recording (PMR) head with single or double coil layers and with a small write shield stitched onto a main write shield. The stitched shield allows the main write pole to produce a vertical write field with sharp vertical gradients that is reduced on both sides of the write pole so that adjacent track erasures are eliminated. From a fabrication point of view, both the main pole and the stitched shield are defined and formed using a single photolithographic process, a trim mask and CMP lapping process so that the main shield can be stitched onto a self-aligned main pole and stitched shield.
    Type: Grant
    Filed: December 11, 2007
    Date of Patent: February 9, 2010
    Assignee: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Kenichi Takano
  • Patent number: 7646568
    Abstract: Improved magnetic devices have been fabricated by replacing the conventional seed layer (typically Ta) with a bilayer of Ru on Ta. Although both Ru and Ta layers are ultra thin (between 5 and 20 Angstroms), good exchange bias between the seed and the AFM layer (IrMn about 70 Angstroms thick) is retained. This arrangement facilitates minimum shield-to-shield spacing and gives excellent performance in CPP, CCP-CPP, or TMR configurations.
    Type: Grant
    Filed: December 23, 2005
    Date of Patent: January 12, 2010
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Hui-Chuan Wang, Tong Zhao, Yu-Hsia Chen, Min Li, Cherng-Chyi Han
  • Patent number: 7631418
    Abstract: A manufacturing process is provided where aggressive (i.e. tight tolerance) stitching offers several advantages for magnetic write heads but at the cost of some losses during pole trimming. This problem has been overcome by replacing the alumina filler layer, that is used to protect the stitched pole during trimming, with a layer of electroplated material. Because of the superior step coverage associated with the plating method of deposition, pole trimming can then proceed without the introduction of stresses to the stitched pole while it is being trimmed.
    Type: Grant
    Filed: July 26, 2007
    Date of Patent: December 15, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Mao-Min Chen, Laurie Lauchlan, Lei Zhang
  • Publication number: 20090116145
    Abstract: A PMR writer with a tapered main pole layer and tapered non-magnetic top-shaping layer is disclosed that minimizes trailing shield saturation. A second non-magnetic top shaping layer may be employed to reduce the effective TH size while the bulk of the trailing shield is thicker to allow a larger process window for back end processing. A sloped surface with one end at the ABS and a second end 0.05 to 0.3 microns from the ABS is formed at a 10 to 80 degree angle to the ABS and includes a sloped surface on the upper portion of the main pole layer and on the non-magnetic top shaping layer. An end is formed on the second non-magnetic top shaping layer at the second end of the sloped surface followed by forming a conformal write gap layer and then depositing the trailing shield on the write gap layer and along the ABS.
    Type: Application
    Filed: November 2, 2007
    Publication date: May 7, 2009
    Inventors: Liejie Guan, Joe Smyth, Moris Dovek, Yoshitaka Sasaki, Cherng-Chyi Han
  • Patent number: 7529067
    Abstract: Although it is known that exchange bias can be utilized in abutted junctions for longitudinal stabilization, a relatively large moment is needed to pin down the sensor edges effectively. Due to the inverse dependence of the exchange bias on the magnetic layer thickness, a large exchange bias has been difficult to achieve by the prior art. This problem has been solved by introducing a structure in which the magnetic moment of the bias layer has been approximately doubled by pinning it from both above and below through exchange with antiferromagnetic layers. Additionally, since the antiferromagnetic layer is in direct abutted contact with the free layer, it acts directly to help stabilize the sensor edge, which is an advantage over the traditional magnetostatic pinning that had been used.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: May 5, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Yun-Fei Li, Hui-Chuan Wang, Chyu-Jiuh Torng, Cherng-Chyi Han, Mao-Min Chen
  • Publication number: 20090091862
    Abstract: A PMR head comprises a substrate, a magnetic pole formed over the substrate, the pole having a pole tip having a cross-sectional tapered shape wherein the pole tip is surrounded by a write gap layer, an integrated shield comprising side shields on the substrate laterally surrounding the pole tip and a trailing shield overlying the pole tip and integral with the side shields.
    Type: Application
    Filed: February 25, 2008
    Publication date: April 9, 2009
    Inventors: Cherng Chyi Han, Lijie Guan, Joe Smyth, Moris Dovek
  • Publication number: 20090009907
    Abstract: A laminated main pole layer is disclosed in which a non-AFC scheme is used to break the magnetic coupling between adjacent high moment layers and reduce remanence in a hard axis direction while maintaining a high magnetic moment and achieving low values for Hch, Hce, and Hk. An amorphous material layer with a thickness of 3 to 20 Angstroms and made of an oxide, nitride, or oxynitride of one or more of Hf, Zr, Ta, Al, Mg, Zn, or Si is inserted between adjacent high moment stacks. The laminated structure also includes an alignment layer below each high moment layer within each stack. In one embodiment, a Ru coupling layer is inserted between two high moment layers in each stack to introduce an AFC scheme. An uppermost Ru layer is used as a CMP stop layer. A post annealing process may be employed to further reduce the anisotropy field (Hk).
    Type: Application
    Filed: July 3, 2007
    Publication date: January 8, 2009
    Inventors: Kunliang Zhang, Min Zheng, Min Li, Chen-Jung Chien, Cherng-Chyi Han
  • Publication number: 20080297945
    Abstract: A perpendicular magnetic recording (PMR) head is fabricated with a pole tip shielded laterally by a separated pair of bottom side shields and shielded from above by an upper shield. The bottom side shields surround a lower portion of the pole tip while the upper portion of the pole tip is surrounded by non-magnetic layers. The bottom shields and the non-magnetic layer form wedge-shaped trench in which the pole tip is formed by a self-aligned plating process. The wedge shape is formed by a RIE process using specific gases applied through a masking layer formed of material that has a slower etch rate than the non-magnetic material or the shield material. A masking layer of Ta, Ru/Ta, TaN or Ti, formed on a non-magnetic layer of alumina that is formed on a shield layer of NiFe and using RIE gases of CH3OH, CO or NH3 or their combinations, produces the desired result. A write gap layer and an upper shield is then formed above the side shields and pole.
    Type: Application
    Filed: May 31, 2007
    Publication date: December 4, 2008
    Inventors: Cherng-Chyi Han, Min Li, Fenglin Liu, Lijie Guan
  • Publication number: 20080253035
    Abstract: A process for forming the write pole of a PMR head is described. This write pole is symmetrically located relative to its side shields, This is accomplished, not through optical alignment, but by coating the pole with a uniform layer of non-magnetic material of a predetermined and precise thickness, followed by the formation of the shield layer around this.
    Type: Application
    Filed: March 27, 2007
    Publication date: October 16, 2008
    Inventors: Cherng-Chyi Han, Min Li, Fenglin Liu, Chen-Jung Chien
  • Publication number: 20080197021
    Abstract: A process sequence for forming a soft magnetic layer having Hce and Hch of ?2 Oe, Hk?5 Oe, and Bs of ?24 kG is disclosed. A CoFe or CoFe alloy is electroplated in a 10O C to 25O C. bath (pH 2 to 3) containing Co+2 and Fe+2 ions in addition to boric acid and one or more aryl sulfinate salts to promote magnetic softness in the deposited layer. Peak current density is 30 to 60 mA/cm2. A two step magnetic anneal process is performed to further improve softness. An easy axis anneal is followed by a hard axis anneal or vice versa. In an embodiment where the magnetic layer is a pole layer in a write head, the temperature is maintained in a 180O C to 250O C range and the applied magnetic field is kept a 300 Oe or below to prevent degradation of an adjacent read head.
    Type: Application
    Filed: February 16, 2007
    Publication date: August 21, 2008
    Inventors: Xiaomin Liu, Cherng-Chyi Han, Feiyue Li