Optical data storage disk

A sputtering target consisting of an alloy

• CuxMayMbz
• with
• x>50 at %,
• whereby:
• Ma:
• stands for a second metal,
• Mb:
• stands for a third metal.

A method for manufacturing data storage disks comprising the steps of:

• providing a substrate;
• providing a spacer layer of a material which is transmitting light of a selected wavelength upon a surface of said substrate;
• applying between said spacer layer and said substrate a first layer of a first metal alloy,
• providing upon said spacer layer a second layer of a second metal alloy;
• depositing one of said first and second metal alloys of said first and second layers respectively so that said one thereof is semi-transparent with respect to said light;
• providing in said first and second metal alloys at least one same metal with a fraction in each of said alloys of more than 50 at %, and
• when either of said alloys contain gold, the amount of said gold being 0 to 50 at %.

A method for manufacturing optical storage disks comprising the steps of:

• providing a substrate;
• proving a spacer layer of a material which is transmitting light of a selected wavelength upon a surface of said substrate;
• applying between said spacer layer and said substrate a first layer of a first metal alloy;
• applying upon the yet free surface of said layer a second layer of a second metal alloy;
• selecting at least one of said first and second metal alloys to have at most 50 at % of gold and so that the ratio n/k between the reflection coefficient n and the absorption coefficient k of said at least one alloy in bulk and for light of 650 nm is:
• 0≦n/k≦0.28.