| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high-density sputtering target for forming a phase change optical disc protective film having zinc sulfide-silicon oxide as its principal components, which is capable of reducing particles and nodules produced during sputtering upon sputtering, has minimal variation in quality and capable of improving mass productiveness, and which has minute crystal grains. <P>SOLUTION: Disclosed is a sputtering target formed using powder in which zinc sulfide powder and silicon oxide powder are evenly mixed and dispersed, wherein, when the medium grain diameters of zinc sulfide in which the sulfate radical (SO<SB>4</SB>) is 0.05 to 0.35 wt.% and silicon oxide are respectively given as A μm and B μm, and the mixture ratio of silicon oxide is given as M mol%, 1.4≤B/A is satisfied within the range of 0.1 μm<A<10 μm, 0.5 μm<B<15 μm and 15 mol%≤M; when the specific surface areas are respectively given as Cm<SP>2</SP>/g and Dm<SP>2</SP>/g, and the mixture ratio of silicon oxide is given as M mol%, 3.5≤C/D is satisfied within the range of 5 m<SP>2</SP>/g≤C≤40 m<SP>2</SP>/g, 0.5 m<SP>2</SP>/g≤D≤15 m<SP>2</SP>/g and 15 mol%≤M; when the grain diameter A converted specific surface area is given as Em<SP>2</SP>/g, 15≤C/E; and when the grain diameter B converted specific surface area is given as Fm<SP>2</SP>/g, D/F≤5. <P>COPYRIGHT: (C)2009,JPO&INPIT |
