Patents by Inventor Meoung-Whan Cho

Meoung-Whan Cho 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: 20090045398
    Abstract: A manufacture method that can manufacture ZnO based compound semiconductor crystal of good quality. A ZnO substrate is prepared to have a principal surface made of a plurality of terraces of (0001) planes arranged stepwise along an m-axis direction, the envelop of the principal surface being inclined relative to the (0001) plane by about 2 degrees or less. ZnO based compound semiconductor crystal is grown on the principal surface.
    Type: Application
    Filed: September 27, 2008
    Publication date: February 19, 2009
    Inventors: Hiroyuki Kato, Michihiro Sano, Katsumi Maeda, Hiroshi Yoneyama, Takafumi Yao, Meoung Whan Cho
  • Publication number: 20080299746
    Abstract: A semiconductor substrate fabrication method according to the first aspect of this invention is characterized by including a preparation step of preparing an underlying substrate, a stacking step of stacking, on the underlying substrate, at least two multilayered films each including a peeling layer and a semiconductor layer, and a separation step of separating the semiconductor layer.
    Type: Application
    Filed: August 24, 2006
    Publication date: December 4, 2008
    Inventors: Takafumi Yao, Meoung-Whan Cho
  • Publication number: 20080261378
    Abstract: A GaN-based thin film (thick film) is grown using a metal buffer layer grown on a substrate. (a) A metal buffer layer (210) made of, for example, Cr or Cu is vapor-deposited on a sapphire substrate (120). (b) A substrate obtained by vapor-depositing the metal buffer layer (210) on the sapphire substrate (120) is nitrided in an ammonia gas ambient, thereby forming a metal nitride layer (212). (c) A GaN buffer layer (222) is grown on the nitrided metal buffer layers (210, 212). (d) Finally, a GaN single-crystal layer (220) is grown. This GaN single-crystal layer (220) can be grown to have various thicknesses depending on the objects. A freestanding substrate can be fabricated by selective chemical etching of the substrate fabricated by the above steps. It is also possible to use the substrate fabricated by the above steps as a GaN template substrate for fabricating a GaN-based light emitting diode or laser diode.
    Type: Application
    Filed: March 31, 2006
    Publication date: October 23, 2008
    Applicant: TOHOKU TECHNO ARCH CO., LTD.
    Inventors: Takafumi Yao, Meoung-Whan Cho
  • Patent number: 7438762
    Abstract: A manufacture method that can manufacture ZnO based compound semiconductor crystal of good quality. A ZnO substrate is prepared to have a principal surface made of a plurality of terraces of (0001) planes arranged stepwise along an m-axis direction, the envelop of the principal surface being inclined relative to the (0001) plane by about 2 degrees or less. ZnO based compound semiconductor crystal is grown on the principal surface.
    Type: Grant
    Filed: August 24, 2006
    Date of Patent: October 21, 2008
    Assignee: Stanley Electric Co., Ltd., Tokyo Denpa Co., Ltd., and Tohoku University
    Inventors: Hiroyuki Kato, Michihiro Sano, Katsumi Maeda, Hiroshi Yoneyama, Takafumi Yao, Meoung Whan Cho
  • Patent number: 6664570
    Abstract: A p-type contact electrode device in a ZnSe-based II-VI compound semiconductor, which electrode device uses, as a contact layer, a BeTe layer having a high p-type doping and a low lattice mismatching with a GaAs substrate to prevent oxidation in air. The device 2 includes a contact layer 5 composed of p-BeTe and a cap layer 4 is composed of p-ZnSe. The cap layer 4 is positioned on the contact layer 5 and an electrode 3 sits atop the cap layer. Preferably, the thickness of the cap layer is 30 to 70 Å and the electrode is composed of gold or gold is dispersed in the cap layer.
    Type: Grant
    Filed: March 27, 2000
    Date of Patent: December 16, 2003
    Assignees: NGK Insulators, Ltd.
    Inventors: Takafumi Yao, Meoung-Whan Cho
  • Publication number: 20020041148
    Abstract: White LED and method for fabricating the same, the white LED including a first light emission part of III-V family compound semiconductor on the substrate having an active layer, a second light emission part of II-VI family compound semiconductor on the first light emission part having an active layer, and electrodes in regions of the substrate, and the first and second light emission parts, thereby providing the white LED having a long lifetime, and implementing a wavelength band of a white or a variety of visible lights by growing the III-V family compound semiconductor with a 635˜780 nm wavelength range and the II-VI family compound semiconductor with a 450˜550 nm wavelength range, with lattices of the two semiconductor matched.
    Type: Application
    Filed: June 8, 2001
    Publication date: April 11, 2002
    Inventors: Meoung Whan Cho, Yao Takafumi
  • Patent number: 5707892
    Abstract: A method for fabricating a semiconductor laser diode includes the steps of forming a double hetero structured semiconductor layer on a substrate, forming a dielectric layer on the double hetero structured semiconductor layer, selectively etching the dielectric layer to expose a portion of the double hetero structured semiconductor layer, selectively removing the exposed semiconductor layer using the dielectric layer as a mask by liquid phase etching, and re growing a semiconductor layer on the etched portion by liquid phase epitaxy.
    Type: Grant
    Filed: November 20, 1995
    Date of Patent: January 13, 1998
    Assignee: LG Electronics, Inc.
    Inventors: Tae Kyung Yoo, Meoung Whan Cho, Ju Ok Seo, Shi Jong Leem, Min Soo Noh