Sumitomo Electric Industries, Limited

Masami Sasaki

Takashi Shimoda

Shin-ichi Akai

Hideki Mori

Kazuhisa Matsumoto

Katsunosuke Aoyagi

Takashi Suzuki

A GaAs single crystal is disclosed containing at least one impurity selected from the group consisting of In, Al, C and S, in which fluctuation of the concentration of the impurity is less that 20% throughout the crystal from which wafers having uniform characteristics can be produced, and which may be prepared by a process comprising, at a high temperature and under high pressure, pulling up the single crystal from a raw material melt containing simple substances Ga and As or GaAs compound as well as at least one impurity while controlling the concentration of As so as to keep a distribution coefficient of the impurity in GaAs within 1.+-.0.1.

GaAs single crystal and preparation thereof

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.

Method of manufacturing gallium phosphide single crystals with low

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Takarazuka, Japan

Masami Sasaki