Loading patent…
AssigneeSumitomo Electric Industries, Ltd.
InventorsTakashi Suzuki, Shin-ichi Akai, Hideki Mori, Katsunosuke Aoyagi, Takashi Shimoda, Kazuhisa Matsumoto, Masami Sasaki
Estimating the term…
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.
A method of manufacturing gallium phosphide single crystals with low defect density, which have a sum of dislocation etch pit density and small conical etch pit density that does not exceed 1.times.10.sup.5 cm.sup.-2 on the (111)B surface of said crystals after removal of mechanically damaged surface layer and subjection to etching with RC etchant for 3.about.5 minutes at a temperature of 65.degree. C..about.75.degree. C., by the liquid encapsulation Czochralski pulling method using a liquid encapsulant and which is characterized by controlling the Czochralski method in the steps of
A method of manufacturing gallium phosphide single crystals as claimed in claim 3, which is further characterized in that a rotating speed of about 10 r.p.m. is employed.
A method of manufacturing gallium phosphide single crystals with low defect density, which have a sum of dislocation etch pit density and small conical etch pit density that does not exceed 1.times.10.sup.5 cm.sup.-2 on the (111)B surface of said crystals after removal of mechanically damaged surface layer and subjection to etching with RC etchant for 3.about.5 minutes at a temperature of 65.degree. C..about.75.degree. C., by the liquid encapsulation Czochralski pulling method using a liquid encapsulant and which is characterized by controlling the Czochralski method in the steps of
Dependencies are inferred from the claim text.