Patents by Inventor Katsunosuke Aoyagi

Katsunosuke Aoyagi 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: 4303464
    Abstract: Gallium phosphide single crystals with low defect density which are manufactured by the liquid encapsulation Czochralski pulling method and which are characterized in that they are doped or not doped with at least one kind of dopant which is electrically active in gallium phosphide and are so doped as to have at least one dopant such as boron or some other strongly reducing impurity which has a reducing activity equal to or greater than that of boron remain in the crystals in a quantity not less than 1.times.10.sup.17 cm.sup.-3 and the sum of dislocation etch pit density and small conical etch pit density of the surface (111)B which has been subjected to etching for 3 to 5 minutes with RC etchant at a temperature of 65.degree. C..about.75.degree. C. after removing the mechanically damaged layer on the surface does not exceed 1.times.10.sup.5 cm.sup.-2, and a method of manufacturing the crystals.
    Type: Grant
    Filed: March 14, 1980
    Date of Patent: December 1, 1981
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takashi Suzuki, Shin-ichi Akai, Hideki Mori, Katsunosuke Aoyagi, Takashi Shimoda, Kazuhisa Matsumoto, Masami Sasaki