METHOD FOR STORING METALLIC LANTHANUM TARGET, VACUUM-SEALED METALLIC LANTHANUM TARGET, AND THIN FILM FORMED BY SPUTTERING USING METALLIC LANTHANUM TARGET

摘要

This method for storing a metallic lanthanum sputtering target is characterized by: processing ahead of time in a manner so that the surface roughness (Ra) of a metallic lanthanum target that is to be stored becomes no greater than 1 μm; then inserting the metallic lanthanum target, to which a lanthanum fluoride coating has been formed, into a vacuum pack having an oxygen permeability of no greater than 0.1 cm³/m²·24h·atm and a water vapor permeability of no greater than 0.1 g/m²·24h; and then evacuating, sealing, and storing the vacuum pack. The present invention provides a technique that contrives a method for storing targets of metallic lanthanum, a rare earth metal, suppresses the phenomenon of turning into powder due to oxidation of the target due to residual and infiltrated air, and enables long-term storage in a usable state as a sputtering target.