Electroformed sputtering target

Abstract

A sputtering target comprising an inverted annular trough encircling a central cylindrical well, and additionally comprising a plurality of electroplated layers of sputtering material is described. The sputtering material comprises at least one of aluminum, copper, tantalum, titanium and tungsten.

1 . A sputtering target comprising (i) an inverted annular trough comprising cylindrical outer and inner sidewalls and a top wall, the inverted annular trough encircling a central cylindrical well having a bottom wall, and (ii) a plurality of electroplated layers of sputtering material comprising a first layer of sputtering material having an underlying surface and a second layer of sputtering material deposited onto the underlying surface of the first layer, the first and second layers being absent a discrete crystalline boundary therebetween, and the sputtering material comprising at least one of aluminum, copper, tantalum, titanium and tungsten.  
   
   
       2 . A target according to  claim 1  wherein the first and second electroplated layers of sputtering material consists essentially of copper, tantalum, titanium, aluminum or tungsten.  
   
   
       3 . A target according to  claim 1  wherein the first and second electroplated layers comprise grains having a grain size of from about 10 μm to about 100 μm.  
   
   
       4 . A target according to  claim 1  comprising additional electroplated layers.  
   
   
       5 . A sputtering method comprising: 
 (a) placing a substrate in a sputtering chamber;    (b) providing in the chamber, a sputtering target comprising an inverted annular trough comprising cylindrical outer and inner sidewalls and a top wall, the inverted annular trough encircling a central cylindrical well having a bottom wall, and the sputtering target further comprising first and second electroplated layers of sputtering material, the first layer of sputtering material having an underlying surface and the second layer of sputtering material deposited onto the underlying surface of the first layer, and the first and second layers being absent a discrete crystalline boundary therebetween;    (c) providing a process gas in the sputtering chamber; and    (d) electrically biasing the target relative to a wall or support in the chamber to energize the process gas to sputter material from the target onto the substrate.    
   
   
       6 . A method according to  claim 5  wherein (b) comprises mounting the target in the sputtering chamber so that the second layer of sputtering material faces a surface of the substrate.  
   
   
       7 . A sputtering chamber comprising: 
 (a) a substrate support;    (b) a sputtering target facing the substrate support, the sputtering target comprising an inverted annular trough comprising cylindrical outer and inner sidewalls and a top wall, the inverted annular trough encircling a central cylindrical well having a bottom wall, and the sputtering target further comprising first and second electroplated layers of sputtering material, the first layer of sputtering material having an underlying surface and the second layer of sputtering material deposited onto the underlying surface of the first layer such that the first and second layers of sputtering material are absent a discrete crystalline boundary therebetween;    (c) a gas delivery system to provide a gas in the chamber;    (d) a gas energizer to energize the gas to sputter the sputtering material from the sputtering target and onto the substrate; and    (e) an exhaust system to exhaust the gas.    
   
   
       8 . A chamber according to  claim 7  wherein the first and second electroplated layers comprise least one of copper, aluminum, tantalum, titanium and tungsten.  
   
   
       9 . A chamber according to  claim 7  wherein the first and second electroplated layers comprise grains having a grain size of from about 10 μm to about 100 μm.  
   
   
       10 . A chamber according to  claim 7  wherein the first and second electroplated layers comprise additional electroplated layers.  
   
   
       11 . A sputtering target comprising an inverted annular trough comprising cylindrical outer and inner sidewalls and a top wall, the inverted annular trough encircling a central cylindrical well having a bottom wall, the target further comprising a plurality of electroplated layers of sputtering material that include a first electroplated layer of sputtering material and a second electroplated layer of sputtering material deposited onto a surface of the first electroplated layer, and the first and second electroplated layers forming a unitary structure that is absent a sharp crystalline boundary therebetween.  
   
   
       12 . A target according to  claim 11  wherein the plurality of electroplated layers of sputtering material comprise at least one of aluminum, copper, tantalum, titanium and tungsten.  
   
   
       13 . A target according to  claim 11  wherein the plurality of electroplated layers of sputtering material comprise grains having a grain size of from about 10 μm to about 100 μm.  
   
   
       14 . A sputtering target comprising: 
 (a) an inverted annular trough comprising cylindrical outer and inner sidewalls and a top wall, the inverted annular trough encircling a central cylindrical well having a bottom wall; and    (b) first and second electroplated layers of sputtering material, wherein the first layer of sputtering material has a surface and the second layer of sputtering material is deposited onto the surface of the first layer to form a unitary and continuous structure that is absent a discrete and sharp crystalline boundary therebetween, the sputtering material comprising grains of at least one of aluminum, copper, tantalum, titanium, and tungsten, the grains having a grain size of from about 10 μm to about 100 μm.    
   
   
       15 . A target according to  claim 14  comprising additional electroplated layers.  
   
   
       16 . A sputtering method comprising: 
 (a) placing a substrate in a sputtering chamber;    (b) providing in the chamber, a sputtering target comprising an inverted annular trough comprising cylindrical outer and inner sidewalls and a top wall, the inverted annular trough encircling a central cylindrical well having a bottom wall, and the target further comprising first and second electroplated layers of sputtering material that include a first electroplated layer of sputtering material having an underlying surface and a second electroplated layer of sputtering material deposited onto the underlying surface of the first layer such that the first and second electroplated layers form a unitary structure that is absent a sharp crystalline boundary, and the sputtering material comprising at least one of aluminum, copper, tantalum, titanium and tungsten;    (c) providing a process gas in the sputtering chamber; and    (d) electrically biasing the target relative to a wall or support in the chamber to energize the process gas to sputter material from the target onto the substrate.    
   
   
       17 . A method according to  claim 16  wherein (b) comprises the target facing a surface of the substrate.