Patents by Inventor Jerome C. Bhat

Jerome C. Bhat 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: 7064353
    Abstract: A relatively small ESD protection diode is formed on the same chip as a light emitting diode. In one embodiment, the ESD diode is a mesa-type diode isolated from the light emitting diode by a trench. To reduce the series resistance of the ESD diode, the PN junction and metal contact to the semiconductor material is made long and expands virtually the width of the chip. Various configurations of the PN junction and the N and P metal contacts for the ESD diode are described for increasing the breakdown voltage and for improved testing.
    Type: Grant
    Filed: May 26, 2004
    Date of Patent: June 20, 2006
    Assignee: Philips Lumileds Lighting Company, LLC
    Inventor: Jerome C. Bhat
  • Patent number: 6995402
    Abstract: A mount for a semiconductor light emitting device includes an integrated reflector cup. The reflector cup includes a wall formed on the mount and shaped and positioned to reflect side light emitted from the light emitting device along a vertical axis of the device/mount combination. The wall may be covered by a reflective material such as a reflective metal.
    Type: Grant
    Filed: October 3, 2003
    Date of Patent: February 7, 2006
    Assignee: Lumileds Lighting, U.S., LLC
    Inventors: Michael J. Ludowise, Jerome C. Bhat
  • Patent number: 6946685
    Abstract: Silver electrode metallization in light emitting devices is subject to electrochemical migration in the presence of moisture and an electric field. Electrochemical migration of the silver metallization to the pn junction of the device results in an alternate shunt path across the junction, which degrades efficiency of the device. In accordance with a form of this invention, a migration barrier is provided for preventing migration of metal from at least one of the electrodes onto the surface of the semiconductor layer with which the electrode is in contact.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: September 20, 2005
    Assignee: Lumileds Lighting U.S., LLC
    Inventors: Daniel A. Steigerwald, Michael J. Ludowise, Steven A. Maranowski, Serge L. Rudaz, Jerome C. Bhat
  • Patent number: 6891197
    Abstract: A dielectric layer is formed on the mesa wall of a flip-chip LED. The dielectric layer is selected to maximize reflection of light incident at angles ranging from 10 degrees towards the substrate to 30 degrees away from the substrate. In some embodiments, the LED is a III-nitride device with a p-contact containing silver, the dielectric layer adjacent to the mesa wall is a material with a low refractive index compared to GaN, such as Al2O3.
    Type: Grant
    Filed: June 12, 2003
    Date of Patent: May 10, 2005
    Assignee: Lumileds Lighting U.S., LLC
    Inventors: Jerome C. Bhat, Michael J. Ludowise, Daniel A. Steigerwald
  • Patent number: 6885035
    Abstract: A light emitting device includes several LEDs, mounted on a shared submount, and coupled to circuitry formed on the submount. The LEDs can be of the III-Nitride type. The architecture of the LEDs can be either inverted, or non-inverted. Inverted LEDs offer improved light generation. The LEDs may emit light of the same wavelength or different wavelengths. The circuitry can couple the LEDs in a combination of series and parallel, and can be switchable between various configurations. Other circuitry can include photosensitive devices for feedback and control of the intensity of the emitted light, or an oscillator, strobing the LEDs.
    Type: Grant
    Filed: May 15, 2001
    Date of Patent: April 26, 2005
    Assignee: Lumileds Lighting U.S., LLC
    Inventors: Jerome C. Bhat, Daniel A. Steigerwald, Reena Khare
  • Patent number: 6876008
    Abstract: A device includes a submount, and a semiconductor light emitting device mounted on first and second conductive regions on a first side of the submount in a flip chip architecture configuration. The submount has third and fourth conductive regions on a second side of the submount. The third and fourth conductive regions may be used to solder the submount to structure such as a board, without the use of wire bonds. The first and third conductive regions are electrically connected by a first conductive layer and the second and fourth conductive regions are electrically connected by a second conductive layer. The first and second conductive layers may be disposed on the outside of the submount or within the submount.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: April 5, 2005
    Assignee: Lumileds Lighting U.S., LLC
    Inventors: Jerome C. Bhat, Cresente S. Elpedes, Paul S. Martin, Serge L. Rudaz
  • Patent number: 6828596
    Abstract: In accordance with the invention, a light emitting device includes a substrate, a layer of first conductivity type overlying the substrate, a light emitting layer overlying the layer of first conductivity type, and a layer of second conductivity type overlying the light emitting layer. A plurality of vias are formed in the layer of second conductivity type, down to the layer of first conductivity type. The vias may be formed by, for example, etching, ion implantation, or selective growth of the layer of second conductivity type. A set of first contacts electrically contacts the layer of first conductivity type through the vias. A second contact electrically contacts the layer of second conductivity type. In some embodiments, the area of the second contact is at least 75% of the area of the device. In some embodiments, the vias are between 2 and 100 microns wide and spaced between 5 and 1000 microns apart.
    Type: Grant
    Filed: June 13, 2002
    Date of Patent: December 7, 2004
    Assignee: Lumileds Lighting U.S., LLC
    Inventors: Daniel A. Steigerwald, Jerome C. Bhat, Michael J. Ludowise
  • Publication number: 20040113163
    Abstract: A light emitting device includes a substrate, a textured layer overlying the substrate, at least one III-nitride layer overlying the textured layer, and a substantially planar light emitting region. Devices incorporating scattering layers may be formed by several different methods. In a first method, an epitaxial layer is deposited then etched to form the textured layer. In a second method, a photomask is deposited and patterned to create openings in the photomask. The textured layer is then preferentially deposited in the openings formed in the photomask. In a third method, the textured layer is deposited under conditions that favor three-dimensional growth, then optionally annealed.
    Type: Application
    Filed: December 11, 2002
    Publication date: June 17, 2004
    Inventors: Daniel A. Steigerwald, Jerome C. Bhat
  • Publication number: 20030230754
    Abstract: In accordance with the invention, a light emitting device includes a substrate, a layer of first conductivity type overlying the substrate, a light emitting layer overlying the layer of first conductivity type, and a layer of second conductivity type overlying the light emitting layer. A plurality of vias are formed in the layer of second conductivity type, down to the layer of first conductivity type. The vias may be formed by, for example, etching, ion implantation, or selective growth of the layer of second conductivity type. A set of first contacts electrically contacts the layer of first conductivity type through the vias. A second contact electrically contacts the layer of second conductivity type. In some embodiments, the area of the second contact is at least 75% of the area of the device. In some embodiments, the vias are between 2 and 100 microns wide and spaced between 5 and 1000 microns apart.
    Type: Application
    Filed: June 13, 2002
    Publication date: December 18, 2003
    Inventors: Daniel A. Steigerwald, Jerome C. Bhat, Michael J. Ludowise
  • Publication number: 20030205712
    Abstract: A dielectric layer is formed on the mesa wall of a flip-chip LED. The dielectric layer is selected to maximize reflection of light incident at angles ranging from 10 degrees towards the substrate to 30 degrees away from the substrate. In some embodiments, the LED is a III-nitride device with a p-contact containing silver, the dielectric layer adjacent to the mesa wall is a material with a low refractive index compared to GaN, such as Al2O3.
    Type: Application
    Filed: June 12, 2003
    Publication date: November 6, 2003
    Inventors: Jerome C. Bhat, Michael J. Ludowise, Daniel A. Steigerwald
  • Publication number: 20010032985
    Abstract: A light emitting device includes several LEDs, mounted on a shared submount, and coupled to circuitry formed on the submount. The LEDs can be of the III-Nitride type. The architecture of the LEDs can be either inverted, or non-inverted. Inverted LEDs offer improved light generation. The LEDs may emit light of the same wavelength or different wavelengths. The circuitry can couple the LEDs in a combination of series and parallel, and can be switchable between various configurations. Other circuitry can include photosensitive devices for feedback and control of the intensity of the emitted light, or an oscillator, strobing the LEDs.
    Type: Application
    Filed: May 15, 2001
    Publication date: October 25, 2001
    Inventors: Jerome C. Bhat, Daniel A. Steigerwald, Reena Khare