Grid providing beamlet steering

Abstract

A grid assembly coupled to a discharge chamber of an ion beam source is configured for steering ion beamlets emitted from the discharge chamber at circularly asymmetrically determined steering angles. The grid assembly includes at least first and a second grid with a substantially circular pattern of holes, wherein each grid comprises holes positioned adjacent to one another. A plurality of the holes of the second grid is positioned with offsets relative to corresponding holes in the first grid. Due to the offsets in the holes in the second grid, ions passing through the offset holes are electrostatically attracted towards the closest circumferential portion of the downstream offset holes. Thus, the trajectories of ions passing through the offset holes are altered. The beamlet is steered by predetermined asymmetric angles. The predetermined steering angles are dependent upon the hole offsets, voltage applied to the grids, and the distance between the grids.

1 . An apparatus comprising:
 a grid assembly with a substantially elliptical pattern of holes configured to propel a plurality of ion beamlets from the grid assembly in a substantially elliptically asymmetric distribution of steering angles.   
     
     
         2 . The apparatus of  claim 1 , wherein the grid assembly includes a first grid and a second grid, and wherein one or more of the steering angles is achieved by offsetting a hole in the second grid relative to a corresponding hole in the first grid. 
     
     
         3 . The apparatus of  claim 2 , wherein the grid assembly further includes a third grid, and wherein one or more of the steering angles is achieved by offsetting a hole in the third grid relative to a corresponding hole in the second grid. 
     
     
         4 . The apparatus of  claim 1 , wherein the one or more of the steering angles is achieved by dishing a grid surface of the grid assembly. 
     
     
         5 . The apparatus of  claim 1 , further comprising:
 an ion source configured to generate ions that pass through the grid assembly and emerge from the grid assembly as the plurality of ion beamlets with the elliptically asymmetric distribution of steering angles.   
     
     
         6 . The apparatus of  claim 1 , further comprising:
 a target assembly oriented in a path of the plurality of ion beamlets and configured to generate a plume of material sputtered from one or more targets of the target assembly.   
     
     
         7 . The apparatus of  claim 6 , further comprising:
 a substrate assembly oriented in a path of the plume of sputtered material and configured to receive the sputtered material onto one or more substrates of the substrate assembly.   
     
     
         8 . The apparatus of  claim 1 , wherein the substantially elliptical pattern of holes is substantially circular. 
     
     
         9 . A method comprising:
 propelling a plurality of ion beamlets from a grid assembly with a substantially elliptical pattern of holes in a substantially elliptically asymmetric distribution of steering angles.   
     
     
         10 . The method of  claim 9 , wherein the grid assembly includes a first grid and a second grid, and wherein one or more of the steering angles is achieved by offsetting a hole in the second grid relative to a corresponding hole in the first grid. 
     
     
         11 . The method of  claim 10 , wherein the grid assembly further includes a third grid, and wherein one or more of the steering angles is achieved by offsetting a hole in the third grid relative to a corresponding hole in the second grid. 
     
     
         12 . The method of  claim 9 , wherein the one or more of the steering angles is achieved by dishing a grid surface of the grid assembly. 
     
     
         13 . The method of  claim 9 , further comprising:
 generating ions that are propelled from the grid assembly as the plurality of ion beamlets with the elliptically asymmetric distribution of steering angles.   
     
     
         14 . The method of  claim 9 , further comprising:
 sputtering material from one or more targets of a target assembly oriented in a path of the plurality of ion beamlets into a sputter plume.   
     
     
         15 . The method of  claim 14 , further comprising:
 depositing material within the sputter plume on one or more substrates of a substrate assembly oriented in a path of the sputter plume.   
     
     
         16 . The method of  claim 9 , wherein the substantially elliptical pattern of holes is substantially circular. 
     
     
         17 . An apparatus comprising:
 a first grid with a substantially elliptical pattern of holes; and   a second grid, wherein one of more holes in the second grid are offset relative to a corresponding hole in the first grid, and wherein the offset holes in the first grid and the second grid are configured to propel a plurality of ion beamlets from the first grid and the second grid in a substantially elliptically asymmetric distribution of steering angles.   
     
     
         18 . The apparatus of  claim 17 , further comprising:
 a target assembly oriented in a path of the plurality of ion beamlets and configured to generate a plume of material sputtered from one or more targets of the target assembly.   
     
     
         19 . The apparatus of  claim 18 , further comprising:
 a substrate assembly oriented in a path of the plume of sputtered material and configured to receive the sputtered material onto one or more substrates of the substrate assembly.   
     
     
         20 . The apparatus of  claim 17 , wherein the substantially elliptical pattern of holes is substantially circular.