Patent ID: 7699948

Claim:
A method of manufacturing a Ta sputtering target, comprising the steps of: forming a Ta ingot or billet having a predetermined diameter by melting and casting a Ta raw material having a purity of 4N5 (99.995%) or greater; cold extend forging the ingot or billet such that the predetermined diameter is reduced, and after said cold extend forging step, recrystallization annealing the ingot or billet a first time at a temperature of 1373K to 1673K; after said cold extend forging and first recrystallization annealing steps, cold mix forging the ingot or billet and then recrystallization annealing the ingot or billet a second time at a temperature of 1373K to 1673K; and after said cold mix forging and second recrystallization annealing steps, further cold mix forging the ingot or billet, and thereafter, conducting additional recrystallization annealing of the ingot or billet at a temperature between a recrystallization starting temperature and 1373K; an average crystal grain diameter of the target being made to be a fine crystal grain size of 80 μm or less and the target being made to have no uneven macrostructure in the form of streaks or aggregates on a surface of the target and inside of the target.