Dual power feed rotary sputtering cathode

Abstract

A rotary sputtering cathode assembly is provided that comprises a rotatable target cylinder having a first end and an opposing second end. A first power transfer apparatus is configured to carry radio frequency power to the first end of the target cylinder, and a second power transfer apparatus is configured to carry radio frequency power to the second end of the target cylinder. Radio frequency power signals are simultaneously delivered to both of the first and second ends of the target cylinder during a sputtering operation.

What is claimed is: 
     
         1 . A rotary sputtering cathode assembly, comprising:
 a rotatable target cylinder having a first end and an opposing second end;   a first end-block connected to the first end of the rotatable target cylinder, wherein the first end block includes a first set of rotary water seals configured to provide separation between water and atmosphere, and a first set of rotary vacuum seals configured to provide separation between vacuum and atmosphere;   a first power transfer apparatus operatively coupled to the first end-block, the first power transfer apparatus including a first power supply bus and a first static conductive element coupled to the first power supply bus, wherein the first static conductive element is in contact with a first rotary electrical contact connected to the rotatable target cylinder;   a second end-block coupled to the second end of the rotatable target cylinder, wherein the second end block includes a second set of rotary water seals configured to provide separation between water and atmosphere, a second set of rotary vacuum seals configured to provide separation between vacuum and atmosphere;   a second power transfer apparatus operatively coupled to the second end-block, the second power transfer apparatus including a second power supply bus and a second static conductive element coupled to the second power supply bus, wherein the second static conductive element is in contact with a second rotary electrical contact connected to the rotatable target cylinder; and   a radio frequency (RF) power supply operatively coupled to the first and second power supply busses, wherein an output of the RF power supply is connected to an output conductor;   wherein the first and second power supply busses are respectively coupled to first and second input conductors, which are each coupled to the output conductor by a power splitter;   wherein RF power signals from the RF power supply are configured to be delivered from the output conductor to the first and second power supply busses, to the first and second static conductive elements, to the first and second rotary electrical contacts, and to both of the first and second ends of the rotatable target cylinder during a sputtering operation.   
     
     
         2 . The rotary sputtering cathode assembly of  claim 1 , wherein the first power transfer apparatus and the second power transfer apparatus are located in cooling water of the rotatable target cylinder. 
     
     
         3 . The rotary sputtering cathode assembly of  claim 1 , wherein the first end-block is at cathode potential. 
     
     
         4 . The rotary sputtering cathode assembly of  claim 1 , wherein the rotatable target cylinder includes a target sputtering material comprising a transparent conductive oxide. 
     
     
         5 . The rotary sputtering cathode assembly of  claim 4 , wherein the transparent conductive oxide comprises indium tin oxide. 
     
     
         6 . The rotary sputtering cathode assembly of  claim 1 , wherein the first end block further includes a first set of bearings configured to support the rotatable target cylinder while allowing rotation of the rotatable target cylinder relative to the first end-block. 
     
     
         7 . The rotary sputtering cathode assembly of  claim 6 , wherein the second end block further includes a second set of bearings configured to support the rotatable target cylinder while allowing rotation of the rotatable target cylinder relative to the second end-block. 
     
     
         8 . The rotary sputtering cathode assembly of  claim 1 , wherein the first power transfer apparatus and the second power transfer apparatus provide substantially equal conductance paths from the RF power supply to each end of the rotatable target cylinder. 
     
     
         9 . The rotary sputtering cathode assembly of  claim 1 , wherein the first and second input conductors are of substantially equal length. 
     
     
         10 . The rotary sputtering cathode assembly of  claim 1 , wherein the first and second input conductors respectively terminate at the first and second power supply busses. 
     
     
         11 . The rotary sputtering cathode assembly of  claim 1 , wherein the RF power supply is operatively coupled to the first and second power supply busses without a direct current (DC) power supply.