Patents by Inventor Vignesh SUNDAR

Vignesh SUNDAR 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: 20180294405
    Abstract: A method for etching a magnetic tunneling junction (MTJ) structure is described. A stack of MTJ layers is provided on a bottom electrode. A top electrode is provided on the MTJ stack. The top electrode is patterned. Thereafter, the MTJ stack not covered by the patterned top electrode is oxidized or nitridized. Then, the MTJ stack is patterned to form a MTJ device wherein any sidewall re-deposition formed on sidewalls of the MTJ device is non-conductive and wherein some of the dielectric layer remains on horizontal surfaces of the bottom electrode.
    Type: Application
    Filed: April 5, 2017
    Publication date: October 11, 2018
    Inventors: Yu-Jen Wang, Dongna Shen, Vignesh Sundar, Sahil Patel
  • Patent number: 9935261
    Abstract: A magnetic device for magnetic random access memory (MRAM), spin torque MRAM, or spin torque oscillator technology is disclosed wherein a perpendicularly magnetized magnetic tunnel junction (p-MTJ) with a sidewall is formed between a bottom electrode and a top electrode. A first dielectric layer is 3 to 400 Angstroms thick, and formed on the p-MTJ sidewall with a physical vapor deposition RF sputtering process to establish a thermally stable interface with the p-MTJ up to temperatures around 400° C. during CMOS fabrication. The first dielectric layer may comprise one or more of B, Ge, and alloys thereof, and an oxide, nitride, carbide, oxynitride, or carbonitride. The second dielectric layer is up to 2000 Angstroms thick and may be one or more of SiOYNZ, AlOYNZ, TiOYNZ, SiCYNZ, or MgO where y+z>0.
    Type: Grant
    Filed: April 5, 2017
    Date of Patent: April 3, 2018
    Assignee: Headway Technologies, Inc.
    Inventors: Sahil Patel, Ru-Ying Tong, Dongna Shen, Yu-Jen Wang, Vignesh Sundar
  • Publication number: 20170256703
    Abstract: A seed layer stack with a uniform top surface having a peak to peak roughness of 0.5 nm is formed by sputter depositing an amorphous layer on a smoothing layer such as Mg where the latter has a resputtering rate 2 to 30× that of the amorphous layer. The uppermost seed (template) layer is NiW, NiMo, or one or more of NiCr, NiFeCr, and Hf while the bottommost seed layer is one or more of Ta, TaN, Zr, ZrN, Nb, NbN, Mo, MoN, TiN, W, WN, and Ru. Accordingly, perpendicular magnetic anisotropy in an overlying magnetic layer is substantially maintained during high temperature processing up to 400° C. and is advantageous for magnetic tunnel junctions in embedded MRAMs, spintronic devices, or in read head sensors. The amorphous seed layer is SiN, TaN, or CoFeM where M is B or another element with a content that makes CoFeM amorphous as deposited.
    Type: Application
    Filed: May 19, 2017
    Publication date: September 7, 2017
    Inventors: Jian Zhu, Guenole Jan, Yuan-Jen Lee, Huanlong Liu, Ru-Ying Tong, Jodi Mari Iwata, Vignesh Sundar, Luc Thomas, Yu-Jen Wang, Sahil Patel
  • Publication number: 20160372146
    Abstract: In one aspect, a magnetic data storage device comprises a template layer, an underlayer, and a magnetic recording layer. The template layer includes a patterned array of protruding features. The underlayer is formed on the patterned array of protruding features of the template layer. The underlayer includes an array pattern of protruding features that aligns with the patterned array of protruding features of the template layer. The magnetic recording layer is formed on the underlayer. The magnetic recording layer includes columnar grains of magnetic material separated by grain boundaries of non-magnetic material, with each columnar grain being on a protruding feature of the array pattern of the underlayer, and the grain boundaries being in trenches between the protruding features of the array pattern of the underlayer.
    Type: Application
    Filed: October 31, 2014
    Publication date: December 22, 2016
    Inventors: Vignesh SUNDAR, Jian-Gang ZHU, David E. LAUGHLIN