Systems And Methods For Workpiece Processing Using Neutral Atom Beams

Abstract

Plasma processing systems and methods are provided. In one example, a system includes a processing chamber having a workpiece support. The workpiece is configured to support a workpiece. The system includes a plasma source configured to induce a plasma from a process gas in a plasma chamber to generate one or more species of negative ions. The system includes a grid structure configured to accelerate the one or more negative ions towards the workpiece. The grid structure can include a first grid plate, a second grid plate, and one or more magnetic elements positioned between the first grid plate and second grid plate to reduce electrons accelerated through the first grid plate. The system can include a neutralizer cell disposed. downstream of the grid structure configured to detach extra electrons from ions of the one or more species of negative ions to generate energetic neutral species for processing the workpiece.

1 - 21 . (canceled) 
     
     
         22 . A plasma processing system, comprising:
 a processing chamber having a workpiece support, the workpiece support configured to support a workpiece;   a plasma source configured to induce a plasma from a process gas in a plasma chamber to generate one or more species comprising negative ions, the plasma source comprising a first plurality of permanent magnets, the first plurality of permanent magnets forming a set of magnetic rings, the plasma chamber comprising a first volume and a second volume;   a grid structure configured to accelerate the one or more negative ions towards the workpiece, the grid structure comprising a first grid plate, a second grid plate, and a second plurality of permanent magnets positioned between the first grid plate and second grid plate, wherein the first grid plate forms a plasma boundary of the plasma chamber, wherein the first grid plate is electrically connected to a conducting part of the plasma chamber and is maintained at the same electrical potential as the conducting part of the plasma chamber;   a neutralizer cell disposed downstream of the grid structure configured to detach extra electrons from ions of the one or more species of negative ions to generate one or more energetic neutral species for processing the workpiece.   
     
     
         23 . The plasma processing system of  claim 22 , wherein the plasma source comprises an inductively coupled plasma source. 
     
     
         24 . The plasma processing system of  claim 22 , wherein the process gas comprises hydrogen, chlorine, or fluorine. 
     
     
         25 . The plasma processing system of  claim 22 , wherein the first grid comprises a first plurality of apertures such that the one or more negative ions pass through the first plurality of apertures. 
     
     
         26 . The plasma processing system of  claim 22 , wherein a potential difference exists between the first grid and the second grid sufficient to accelerate a plurality of beams of the negative ions. 
     
     
         27 . The plasma processing system of  claim 22 , wherein the grid structure comprises a third grid plate. 
     
     
         28 . The plasma processing system of  claim 25 , wherein the second grid plate comprises a second plurality of apertures that are aligned with the first plurality of apertures of the first grid plate in such that the one or more negative ions passing through the first plurality of apertures of the first grid plate pass through corresponding apertures of the second plurality of apertures. 
     
     
         29 . The plasma processing system of  claim 25 , wherein each of the second plurality of permanent magnets has a length dimension generally perpendicular to a direction of ion extraction and is generally parallel to a plane of the grid structure. 
     
     
         30 . The plasma processing system of  claim 29 , wherein the length of each of the second plurality of permanent magnets is greater than a length of one of the first plurality of apertures. 
     
     
         31 . The plasma processing system of  claim 22 , wherein magnetic field strength at one or more pole faces of the one or more magnetic elements is of the order of about 1 kilogauss or less. 
     
     
         32 . The plasma processing system of  claim 22 , wherein the neutralizer cell has a depth in the range of about 10 centimeters to 100 centimeters. 
     
     
         33 . The plasma processing system of  claim 22 , wherein the neutralizer cell comprises a plurality of lasers. 
     
     
         34 . The plasma processing system of  claim 22 , wherein the first grid plate forms a side of the plasma chamber adjacent the second volume.