A method of manufacturing a low α hypoxia metal scandium

摘要

PROBLEM TO BE SOLVED: To improve reliability against soft error, signal delay, wire breakage, etc., at the semiconductor actuation by controlling the contents of uranium, thorium, and oxygen in the metallic scandium to be added to aluminum as semiconductor metallic material to specific extremely low values, respectively. ;SOLUTION: The contents of uranium and thorium in the metallic scandium to be added to aluminum by 0.01-5wt.% are regulated to ≤100wt.ppb, respectively, and also oxygen content is regulated to ≤500wt.ppm. Moreover, this scandium is produced by means of the following stages: a thorium removal stage where a scandium nitrate solution of ≥4N nitric acid concentration is passed through an anion exchange resin; a stage where a scandium hydrochloride solution is passed through an anion exchange resin to remove uranium; a stage where halogenation is performed after the removal of thorium and uranium; a stage where scandium halide is mixed with scadium alloy and these are melted to remove oxygen; and a stage of alloy removal.;COPYRIGHT: (C)1997,JPO