Patents Assigned to AXT, Inc.
  • Patent number: 6580096
    Abstract: A light-emitting diode (LED) constructed of AlGaInP compounds includes a multi-layer window having, in the order of formation, a lightly doped first layer formed of p doped GaP; a low impedance second layer formed of p GaAs; an amorphous conducting layer formed of Indium Tin Oxide (ITO), and a titanium/gold contact. In one embodiment, the contact forms ohmic connections with the second and third layers; and a Schottky diode connection with the first layer. In a second embodiment, the contact forms an ohmic connection with the third layer; and is insulated from direct contact with the first layer.
    Type: Grant
    Filed: June 13, 2002
    Date of Patent: June 17, 2003
    Assignee: AXT, Inc.
    Inventors: John Chen, Bingwen Liang, Robert Shih
  • Publication number: 20030010994
    Abstract: A window structure for Gallium Nitride based Light Emitting Diode comprises: an Mg+ doped P window layer of a GaN compound; a thin semitransparent metal contact layer; an amorphous current spreading layer formed on the contact layer. The contact layer is formed of NiOx\Au; and the current spreading layer is formed of Indium Tin Oxide. The P electrode of the diode comprises a titanium adhesion layer which forms an ohmic connection with the current spreading layer and a Shottky diode connection with the Mg+ doped window layer.
    Type: Application
    Filed: July 15, 2002
    Publication date: January 16, 2003
    Applicant: AXT, Inc.
    Inventors: John Chen, Bingwen Liang, Robert Shih
  • Patent number: 6495867
    Abstract: A GaN based three layer buffer on a sapphire substrate provides a template for growth of a high quality I GaN layer as a substitute substrate for growth of a Nitride based LED.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: December 17, 2002
    Assignee: AXT, Inc.
    Inventors: Changhua Chen, James Dong, Heng Liu
  • Publication number: 20020175337
    Abstract: A GaN based three layer buffer on a sapphire substrate provides a template for growth of a high quality I GaN layer as a substitute substrate for growth of a Nitride based LED.
    Type: Application
    Filed: July 8, 2002
    Publication date: November 28, 2002
    Applicant: AXT, Inc.
    Inventors: Changhua Chen, James Dong, Heng Liu
  • Patent number: 6459098
    Abstract: A Light Emitting Diode (LED) constructed of AlGaInP compounds includes a multi layer window which improves the efficiency of the diode. The window, in the order of formation, includes a lightly doped first layer formed of p doped GaP; a low impedance second layer formed of p GaAs; an amorphous conducting layer formed of Indium Tin Oxide (ITO), and a titanium\gold contact. In one embodiment, the contact forms ohmic connections with the second and third layers; and a Shottky diode connection with first layer. In a second embodiment, the contact forms an ohmic connection with the third layer; and is insulated from direct contact with the first layer.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: October 1, 2002
    Assignee: AXT, Inc.
    Inventors: John Chen, Bingwen Liang, Robert Shih
  • Patent number: 6420736
    Abstract: A window structure for a gallium nitride (GaN)-based light emitting diode (LED) includes a Mg+ doped p window layer of a GaN compound; a thin, semi-transparent metal contact layer; and an amorphous current spreading layer formed on the contact layer. The contact layer is formed of NiOx/Au and the current spreading layer is formed of Indium Tin Oxide. The p electrode of the diode includes a titanium adhesion layer which forms an ohmic connection with the current spreading layer and a Schottky diode connection with the Mg+ doped window layer.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: July 16, 2002
    Assignee: AXT, Inc.
    Inventors: John Chen, Bingwen Liang, Robert Shih