Method for doping sintered tantalum and niobium pellets with nitrogen

摘要

Doped tantalum and niobium pellets with nitrogen is described wherein the resulting pellets are substantially free of nitride precipitate on their outer surfaces. The tantalum and niobium pellets are formed by heating the pellets to a temperature of from about 600-1400° C. in a nitrogen gas atmosphere and then in a vacuum which causes nitrogen contacting a pellet to diffuse into the inner portion of the pellet instead of forming a precipitate. The resulting pellets have improved DCL stability and reliability in comparison to prior art nitrogen-doped tantalum and niobium pellets.