| 摘要 |
PURPOSE:To obtain a metal source containing little of a radioactive heavy metal when a high pure wiring metal source to be used for a sputtering target or for an evaporation source is to be manufactured by a method wherein lattice defects are made to be generated in the surface layer part of a single crystal metal substrate, the substrate thereof is heated to catch impurity atoms existing in the substrate thereinto, and the part thereof is removed. CONSTITUTION:The lattice defects 2 are made to be generated at the position of several mum depth by implanting Ar<+> ions, etc., into the surface of the single crystal Mo substrate 1 containing normally radioactive elements of about several 100ppb, and heat treatment is performed at 1,900-2,000 deg.C for 30-60min in an inert gas atmosphere of Ar or N2, etc., to catch the radioactive elements R of U, Th, etc., moving in the substrate 1 by thermal energy to be fixed in the region 2. After then, the region 2 in which the radioactive elements R are fixed is removed by reactive sputter etching using CCl2F2, etc., to obtain the high pure Mo wiring source 1' having exposed single crystal face with no lattice defect. |
