Patents by Inventor Holin Chang

Holin Chang 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: 6661028
    Abstract: The present invention discloses a light-emitting device (LED) with a textured interface formed by utilizing holographic lithography. Two coherent light beams are overlaid to cause constructive and destructive interference and thereby periodical alternative bright and dark lines are formed. A wafer coated with a photoresist material is exposed under the interference lines. After a developing step, a photoresist pattern with textured surface is formed on the wafer. Thereafter, the textured photoresist pattern is transferred to the wafer by etching process and result in a desired light-emitting device with a textured interface.
    Type: Grant
    Filed: May 14, 2002
    Date of Patent: December 9, 2003
    Assignee: United Epitaxy Company, Ltd.
    Inventors: Tzer-Perng Chen, Chih-Sung Chang, Holin Chang
  • Patent number: 6552369
    Abstract: A light emitting diode (LED) is disclosed. An emitted light can be prevented from being absorbed by a substrate using a Bragg reflector layer with high reflectivity. The present invention provides a Bragg reflector layer comprising a plurality of high aluminum-containing AlGaAs/AlGaInP layers or high aluminum-containing AlGaAs/ low aluminum-containing AlGaInP layers formed on the substrate before the epitaxial structure of the light emitting diode being formed. Since the high aluminum-containing AlGaAs is oxidized and formed an oxide of a lower refraction index, the reflectivity and high reflection zones of the oxidized Bragg reflector layer are much larger. According to the electrical insulation characteristic of the oxide, the Bragg reflector layer can limit the current within the oxidized regions of high aluminum-containing AbGaAs layer. Therefore, the aforementioned light emitting diode structure has a higher brightness than the conventional light emitting diode.
    Type: Grant
    Filed: October 31, 2001
    Date of Patent: April 22, 2003
    Assignee: United Epitaxy Company LTD
    Inventors: Shu-Woei Chiou, Holin Chang, Tzer-Perng Chen, Chih-Sung Chang
  • Publication number: 20020145147
    Abstract: A light emitting diode (LED) is disclosed. The problem of an emitting light absorbed by a substrate can be prevented by using a bragg reflector layer with high reflectivity. The present invention provides a high reflectivity bragg reflector layer to reflect the light generated from LED, which comprises high aluminum-contained AlGaAs/AlGaInP layers or high aluminum-contained AlGaAs/low aluminum-contained AlGaInP layers, formed on the substrate before the vertically stacked epitaxial structure of the light emitting diode is formed. Due to the higher oxidation ability of the high aluminum-contained AlGaAs layers and the lower refraction index of the oxide thereof, the wavelength reflected by the bragg reflector layer can cover a wider spectrum and the reflectivity thereof is very high. Since the oxidized AlGaAs layer is an electrical insulator, the present invention provides electrodes located on the same side of the light emitting diode.
    Type: Application
    Filed: December 18, 2001
    Publication date: October 10, 2002
    Inventors: Shu-Woei Chiou, Holin Chang, Tzer-Perng Chen, Chih-Sung Chang
  • Publication number: 20020134985
    Abstract: The present invention discloses a light-emitting device (LED) with a textured interface formed by utilizing holographic lithography. Two coherent light beams are overlaid to cause constructive and destructive interference and thereby periodical alternative bright and dark lines are formed. A wafer coated with a photoresist material is exposed under the interference lines. After a developing step, a photoresist pattern with textured surface is formed on the wafer. Thereafter, the textured photoresist pattern is transferred to the wafer by etching process and result in a desired light-emitting device with a textured interface.
    Type: Application
    Filed: May 14, 2002
    Publication date: September 26, 2002
    Inventors: Tzer-Perng Chen, Chih-Sung Chang, Holin Chang
  • Patent number: 6455343
    Abstract: The present invention provides a method of manufacturing a light emitting diode based on an epitaxial layer structure. The epitaxial layer structure includes a substrate of a first conductivity type, a lower cladding layer of the first conductivity type formed on a top side of the substrate, an active layer formed on the lower cladding layer, an upper cladding layer of a second conductivity type formed on the active layer, at least one upper aluminum-rich layer formed on the upper cladding layer, and a cap layer formed on the at least one upper aluminum-rich layer. The method includes the steps of forming an opening hole in the epitaxial layer structure for passing through each upper aluminum-rich layer, oxidizing a predetermined region of each upper aluminum-rich layer, filling the opening hole with an insulating material, and forming an upper electrode on the cap layer and a lower electrode on a back side of the substrate.
    Type: Grant
    Filed: March 28, 2000
    Date of Patent: September 24, 2002
    Assignee: United Epitaxy Company, Ltd.
    Inventors: Tzer-Perng Chen, Chih-Sung Chang, Holin Chang
  • Patent number: 6410348
    Abstract: An interface texturing for light-emitting device is formed by utilizing holographic lithography. Two coherent light beams are overlaid to cause constructive and destructive interference and thereby periodical alternative bright and dark lines are formed. A wafer coated with photoresist material is exposed under the interference lines. After developing step, a photoresist pattern with textured surface is formed on the wafer. Thereafter, the textured photoresist pattern is transferred to the wafer by etching process and result in a desired interface texturing.
    Type: Grant
    Filed: August 1, 2000
    Date of Patent: June 25, 2002
    Assignee: United Epitaxxy Company, Ltd.
    Inventors: Tzer-Perng Chen, Chih-Sung Chang, Holin Chang
  • Publication number: 20020055218
    Abstract: A light emitting diode (LED) is disclosed. An emitted light can be prevented from being absorbed by a substrate by using a bragg reflector layer with high reflectivity. The present invention provides a bragg reflector layer comprising a plurality of high aluminum-contained AlGaAs/AlGaInP layers or high aluminumcontained AlGaAs/low aluminum-contained AlGaInP layers formed on the substrate before the epitaxial structure of the light emitting diode being formed. Since the high aluminum-contained AlGaAs is oxidized and formed an oxide of a lower refraction index, the reflectivity and high reflection zones of the oxidized bragg reflector layer are much larger. According to the electrical insulation characteristic of the oxide, the bragg reflector layer can limit the current within the oxidized regions of high aluminum-contained AlGaAs layer. Therefore, the aforementioned light emitting diode structure has a higher brightness than the conventional light emitting diode.
    Type: Application
    Filed: October 31, 2001
    Publication date: May 9, 2002
    Inventors: Shu-Woei Chiou, Holin Chang, Tzer-Perng Chen, Chih-Sung Chang