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

摘要

A method of storing a metal lanthanum sputtering target, wherein a surface of a metal lanthanum target to be stored is processed so as to achieve a roughness Ra of 1 µm or less, a lanthanum fluoride coating is formed on the surface thereof, the metal lanthanum target to which the lanthanum fluoride coating was formed is subsequently charged in a vacuum pack with an oxygen transmission rate of 0.1 cm3/m2 per 24 h at 1 atm or less and a moisture vapor transmission rate of 0.1 g/m2 per 24 h or less, and the vacuum pack is thereafter subject to vacuum suction and sealing for storage. This invention aims to provide technology for enabling the long-term storage of a sputtering target in a usable state by devising the method of storing a metal lanthanum target as a rare earth metal, and thereby inhibiting the degradation phenomenon caused by the oxidation of the target due to residual air or the inclusion of air.