Patents by Inventor Amitava Chattopadhyay

Amitava Chattopadhyay 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: 7440227
    Abstract: A magnetic head has a sensor which employs the “Hall effect”. In one illustrative example, the sensor includes a generally planar body made of a semiconductor heterostructure; first and second contacts comprising first and second drains, respectively, which are formed over a first end of the body and spaced equally apart from a centerline of the body; and a third contact comprising a source formed over a second end of the body which is opposite the first end of the body. The semiconductor heterostructure is comprised of a high mobility two-dimensional electron or hole gas close to an air bearing surface (ABS) of the magnetic head so as to be exposed to magnetic field lines substantially normal to it from magnetically recorded bits. Advantageously, the sensor does not require magnetic materials utilized in conventional sensors and therefore does not suffer from magnetic noise associated therewith.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: October 21, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Amitava Chattopadhyay, Stefan Maat, Ernesto E. Marinero, Bruce Alvin Gurney
  • Patent number: 7295406
    Abstract: An extraordinary magnetoresistive sensor having optimal magnetic sensitivity capable of reading a very narrow and short magnetic bit. The sensor includes a layer of semiconductor layer and a layer of electrically conductive material. The first and second leads are electrically connected with an edge of the semiconductor material, one of the leads being located a distance inward from an end of the sensor. The sensor also includes first and second voltage leads, located on either side of and close to one of the current leads.
    Type: Grant
    Filed: July 22, 2004
    Date of Patent: November 13, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Amitava Chattopadhyay, Robert E. Fontana, Jr., Bruce Alvin Gurney, Stefan Maat, Ernesto E. Marinero
  • Patent number: 7203036
    Abstract: An extraordinary magnetoresistance (EMR) sensor has a planar shunt and planar leads formed on top of the sensor and extending downward into the semiconductor active region, resulting. Electrically conductive material, such as Au or AuGe, is first deposited into lithographically defined windows on top of the sensor. After liftoff of the photoresist a rapid thermal annealing process causes the conductive material to diffuse downward into the semiconductor material and make electrical contact with the active region. The outline of the sensor is defined by reactive etching or other suitable etching techniques. Insulating backfilling material such as Al-oxide is deposited to protect the EMR sensor and the edges of the active region. Chemical mechanical polishing of the structure results in a planar sensor that does not have exposed active region edges.
    Type: Grant
    Filed: July 30, 2004
    Date of Patent: April 10, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Amitava Chattopadhyay, Robert E. Fontana, Jr., Bruce A. Gurney, Stefan Maat, Ernesto E. Marinero
  • Publication number: 20060193080
    Abstract: A magnetic head has a sensor which employs the “Hall effect”. In one illustrative example, the sensor includes a generally planar body made of a semiconductor heterostructure; first and second contacts comprising first and second drains, respectively, which are formed over a first end of the body and spaced equally apart from a centerline of the body; and a third contact comprising a source formed over a second end of the body which is opposite the first end of the body. The semiconductor heterostructure is comprised of a high mobility two-dimensional electron or hole gas close to an air bearing surface (ABS) of the magnetic head so as to be exposed to magnetic field lines substantially normal to it from magnetically recorded bits. Advantageously, the sensor does not require magnetic materials utilized in conventional sensors and therefore does not suffer from magnetic noise associated therewith.
    Type: Application
    Filed: February 28, 2005
    Publication date: August 31, 2006
    Inventors: Amitava Chattopadhyay, Stefan Maat, Ernesto Marinero, Bruce Gurney
  • Publication number: 20060022672
    Abstract: An extraordinary magnetoresistance (EMR) sensor has a planar shunt and planar leads formed on top of the sensor and extending downward into the semiconductor active region, resulting. Electrically conductive material, such as Au or AuGe, is first deposited into lithographically defined windows on top of the sensor. After liftoff of the photoresist a rapid thermal annealing process causes the conductive material to diffuse downward into the semiconductor material and make electrical contact with the active region. The outline of the sensor is defined by reactive etching or other suitable etching techniques. Insulating backfilling material such as Al-oxide is deposited to protect the EMR sensor and the edges of the active region. Chemical mechanical polishing of the structure results in a planar sensor that does not have exposed active region edges.
    Type: Application
    Filed: July 30, 2004
    Publication date: February 2, 2006
    Inventors: Amitava Chattopadhyay, Robert Fontana, Bruce Gurney, Stefan Maat, Ernesto Marinero
  • Publication number: 20060018054
    Abstract: An extraordinary magnetoresistive sensor having optimal magnetic sensitivity capable of reading a very narrow and short magnetic bit. The sensor includes a layer of semiconductor layer and a layer of electrically conductive material. The first and second leads are electrically connected with an edge of the semiconductor material, one of the leads being located a distance inward from an end of the sensor. The sensor also includes first and second voltage leads, located on either side of and close to one of the current leads.
    Type: Application
    Filed: July 22, 2004
    Publication date: January 26, 2006
    Inventors: Amitava Chattopadhyay, Robert Fontana, Bruce Gurney, Stefan Maat, Ernesto Marinero