Sputtering target and method for finishing surface of such target
View Patent ↗Provided is a hollow cathode sputtering target comprising an inner bottom face having a surface roughness of Ra≦1.0 μm, and preferably Ra≦0.5 μm. This hollow cathode sputtering target has superior sputter film evenness (uniformity), generates few arcing and particles, is capable of suppressing the peeling of the redeposited film on the bottom face, and has superior deposition characteristics.
1. A hollow cathode sputtering target comprising an inner bottom face that forms a non-erosion portion of a plastic-worked hollow cathode sputtering target and a cylindrical inner peripheral face that forms an erosion portion of the plastic-worked hollow cathode sputtering target, wherein, upon manufacture, a surface roughness (Ra) of said inner bottom face of said non-erosion portion of the plastic-worked hollow cathode sputtering target being Ra=1.0 μm and being less than a surface roughness (Ra) of said cylindrical inner peripheral face of said erosion portion of the plastic-worked hollow cathode sputtering target.
2. A surface finishing method of a hollow cathode sputtering target comprising the steps of forming a hollow body of the hollow cathode sputtering target via plastic working, and, after said plastic working, polishing and etching an inner bottom face of the target that forms a non-erosion portion of the hollow cathode sputtering target so as to make the surface roughness (Ra) of the inner bottom face, upon manufacture, Ra=1.0 μm and less than a surface roughness (Ra) of a cylindrical inner peripheral face of the hollow cathode sputtering target that forms an erosion portion of the hollow cathode sputtering target.
3. A hollow cathode sputtering target according to claim 1 , wherein said surface roughness of said inner bottom face of said non-erosion portion of the hollow cathode sputtering target is Ra=0.5 μm.
4. A hollow cathode sputtering target according to claim 3 , wherein said target has an outer peripheral edge with a rough face and wherein said outer peripheral edge forms part of said non-erosion portion of the hollow cathode sputtering target.
5. A hollow cathode sputtering target according to claim 4 , wherein said rough face of said outer peripheral edge is an abrasive blasted face.
6. A hollow cathode sputtering target according to claim 5 , wherein said hollow cathode sputtering target is formed from a cladding material.
7. A hollow cathode sputtering target according to claim 1 , wherein said target has an outer peripheral edge with a rough face and wherein said outer peripheral edge forms part of said non-erosion portion of the hollow cathode sputtering target.
8. A hollow cathode sputtering target according to claim 7 , wherein said rough face of said outer peripheral edge is an abrasive blasted face.
9. A hollow cathode sputtering target according to claim 8 , wherein said hollow cathode sputtering target is formed from a cladding material.
10. A hollow cathode sputtering target according to claim 1 , wherein said hollow cathode sputtering target is formed from a cladding material.
11. A method according to claim 2 , wherein said surface roughness of said inner bottom face is made to be Ra=0.5 μm during said polishing and etching step.
12. A hollow cathode sputtering target, consisting of:
a cup-shaped body having an inner peripheral surface defining a hollow cavity within the cup-shaped body and an outer peripheral surface on an exterior of said cup-shaped body, said inner peripheral surface being a sputtering face of said cup-shaped body and said outer peripheral face being a non-erosion face;
said inner peripheral surface consisting of a cylindrical peripheral face, a bottom face, and a curved face defining a boundary between said cylindrical face and said bottom face, said cylindrical peripheral face forming an erosion area of said sputtering face that is eroded during a sputtering operation when a high density plasma is generated within the hollow cavity of the cup-shaped body, and said bottom face forming a non-erosion portion of said cup-shaped body;
a surface roughness (Ra) of said bottom face, upon manufacture, being Ra=1.0 μm and being less than a surface roughness (Ra) of said cylindrical inner peripheral face.
13. A hollow cathode sputtering target according to claim 12 , wherein said surface roughness of said bottom face is Ra=0.5 μm.
14. A hollow cathode sputtering target according to claim 12 wherein said cup-shaped body is made of titanium (Ti).
15. A hollow cathode sputtering target according to claim 12 wherein said cup-shaped body is made of tantalum (Ta).