Apparatus and method for controlling ion beam using electostatic filter

Abstract

An apparatus is provided. The apparatus may include a main chamber, an entrance tunnel, the entrance tunnel having an entrance axis extending into the main chamber; an exit tunnel, connected to the main chamber and defining an exit axis, wherein the entrance tunnel and the exit tunnel define a beam bend of less than 25 degrees therebetween, and an electrode assembly, disposed in the main chamber, and defining a beam path between the entrance tunnel and the exit tunnel. The electrode assembly may include an upper electrode, disposed on a first side of the beam path, and a plurality of lower electrodes, disposed on a second side of the beam path, the plurality of lower electrodes comprising at least three electrodes.

1 . A method of controlling an ion beam, comprising:
 providing an apparatus, comprising a main chamber, containing an electrode assembly, and an exit tunnel;   conducting the ion beam into the main chamber along a first beam trajectory;   applying a plurality of potentials to the electrode assembly to decelerate and deflect the ion beam,   wherein the ion beam exits the main chamber through the exit tunnel, along a second beam trajectory, different from the first beam trajectory, and   wherein the electrode assembly is disposed below a lower surface of the exit tunnel, and no electrodes within the main chamber are disposed above the lower surface of the exit tunnel.   
     
     
         2 . The method of  claim 1 , wherein the applying the plurality of potentials to the electrode assembly, comprises:
 deflecting the ion beam in a first direction, while accelerating the ion beam from a first potential to a second potential; and   deflecting the ion beam in a second direction, opposite the first direction, while decelerating the ion beam to a third potential.   
     
     
         3 . The method of  claim 1 , wherein the first beam trajectory and the second beam trajectory define a beam bend of 25 degrees or less. 
     
     
         4 . The method of  claim 2 , wherein the third potential is less than the first potential. 
     
     
         5 . The method of  claim 1 , the electrode assembly comprising an upper electrode and a plurality of lower electrodes. 
     
     
         6 . The method of  claim 5 , wherein the ion beam comprises a ribbon ion beam, wherein the electrode assembly comprises a plurality of rods, extending along an electrode axis, the electrode axis being oriented perpendicularly to a direction of propagation of the ion beam. 
     
     
         7 . The method of  claim 6 , further comprising conducting the ion beam from the exit tunnel to a substrate. 
     
     
         8 . The method of  claim 7 , further comprising intercepting energetic neutrals entering the main chamber in the exit tunnel, wherein the energetic neutrals do not strike the substrate. 
     
     
         9 . The method of  claim 7 , further comprising intercepting a plurality of sputtered particles from the substrate, within the main chamber, wherein the plurality of sputtered particles do not strike the electrode assembly. 
     
     
         10 . The method of  claim 7 , further comprising setting the exit tunnel and a chamber wall of the main chamber at ground potential, wherein a plurality of negatively charged particles, emitted from the electrode assembly, are intercepted by the exit tunnel and the chamber wall, and wherein the negatively charged particles do not strike the substrate.