Sumitomo Electric Industries, Limited

Takashi Shimoda

Shin-ichi Akai

Hideki Mori

Masami Sasaki

Kazuhisa Matsumoto

Shin-ichi Iguchi

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

A plurality of single-crystal epitaxial layers of semiconductors are simultaneously grown on a plurality of suitable substrates from the liquid phase by a method which includes the step of consecutively, and at times simultaneously, supplying small portions of liquid solution from a solution reservoir onto all the surfaces of the substrates in a plurality of wells which are provided on a surface of a rotatable circular lower plate so that epitaxial growth can be simultaneously carried out in all wells. The solution reservoir is positioned on a radius of the lower plate on which a circular upper plate is also provided in a non-rotatable state relative to the solution reservoir. Small portions of liquid solution are supplied by rotating the lower plate relative to the upper plate and the solution reservoir, and constrained in shape and volume which are adjusted by the upper plate and the wells. The composition and doping level of epitaxial layers are controlled through vapor-liquid communication.

Method for growing epitaxial layers on multiple semiconductor wafers

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Osaka, Japan

Takashi Shimoda