Apparatus for atmospheric pressure reactive atom plasma processing for surface modification

Abstract

Reactive atom plasma processing can be used to shape, polish, planarize and clean the surfaces of difficult materials with minimal subsurface damage. The apparatus and methods use a plasma torch, such as a conventional ICP torch. The workpiece and plasma torch are moved with respect to each other, whether by translating and/or rotating the workpiece, the plasma, or both. The plasma discharge from the torch can be used to shape, planarize, polish, and/or clean the surface of the workpiece, as well as to thin the workpiece. The processing may cause minimal or no damage to the workpiece underneath the surface, and may involve removing material from the surface of the workpiece.

1 . A tool for processing a surface of a workpiece, comprising: 
 a plasma processing chamber in which the workpiece can be positioned;    a plasma torch included in the processing chamber, wherein the plasma torch is operable to perform a plurality of operations to process the surface of the workpiece using reactive atom plasma processing; and    a translator operable to translate at least one of the workpiece and the plasma torch.    
     
     
         2 . The tool according to  claim 1 , wherein: 
 the plasma torch is an ICP torch.    
     
     
         3 . The tool according to  claim 1 , wherein: 
 an operation in the plurality of operations can be one of shaping, cleaning, polishing, and planarizing.    
     
     
         4 . The tool according to  claim 1 , wherein: 
 the plasma torch is operable to perform the plurality of operations while causing minimal or no damage to the workpiece underneath the surface.    
     
     
         5 . The tool according to  claim 1 , wherein: 
 the plasma torch is operable to produce a volatile reaction on the surface of the workpiece.    
     
     
         6 . The tool according to  claim 1 , wherein: 
 the plasma torch includes a multiple head to increase the etch rate of the plasma torch.    
     
     
         7 . The tool according to  claim 1 , further comprising: 
 a controller operable to perform at least one of:    injecting a precursor in the plasma torch in order to create a reactive species from the precursor;    controlling the etch rate of the plasma torch via the precursor;    controlling the mass flow of the precursor into the plasma torch;    maintaining the temperature of the plasma torch between 5,000 and 15,000 degrees C.;    maintaining the processing chamber at about atmospheric pressure, and    using an auxiliary gas to adjust the position of a discharge.    
     
     
         8 . The tool according to  claim 7 , wherein: 
 the precursor can be any one of a solid, liquid, and gas.    
     
     
         9 . The tool according to  claim 1 , wherein: 
 the plasma torch includes an inner tube, an intermediate tube, and an outer tube.    
     
     
         10 . The tool according to  claim 9 , further comprising: 
 a controller operable to perform at least one of:    introducing a precursor into the inner tube of the plasma torch;    introducing an auxiliary gas into the intermediate tube of the plasma torch;    introducing a plasma gas into the outer tube of the plasma torch;    coupling energy to a discharge in the inner tube of the plasma torch; and    restricting the size of a discharge to the inner diameter of the outer tube of the plasma torch.    
     
     
         11 . The tool according to  claim 1 , wherein: 
 the translator includes:    a translation stage capable of rotating the workpiece with respect to the plasma torch; and    a control system capable of being programmed to control the translation stage.    
     
     
         12 . A tool for shaping a surface of a workpiece, comprising: 
 a plasma processing chamber in which the workpiece can be positioned;    a plasma torch included in the processing chamber, wherein the plasma torch is operable to establish an equilibrium in a plasma reaction in the plasma processing chamber, whereby material may be removed from the surface of the workpiece and re-deposited on the surface of the workpiece with the discharge from the plasma torch; and    a translator operable to translate at least one of the workpiece and the plasma torch.    
     
     
         13 . A tool for cleaning a surface of a workpiece, comprising: 
 a plasma processing chamber in which the workpiece can be positioned;    a plasma torch included in the processing chamber, wherein the plasma torch is operable to remove material from the surface of the workpiece using reactive atom plasma processing; and    a translator operable to translate at least one of the workpiece and the plasma torch.    
     
     
         14 . A tool for processing a surface of an optic, comprising: 
 a plasma processing chamber in which the optic can be positioned;    a plasma torch included in the processing chamber, wherein the plasma torch is operable to perform a plurality of operations to process the surface of the optic using reactive atom plasma processing; and    a translator operable to translate at least one of the optic and the plasma torch.    
     
     
         15 . The tool according to  claim 14 , wherein: 
 the optic is a high-damage threshold optic.    
     
     
         16 . A tool for back-etching a wafer, comprising: 
 a plasma processing chamber in which the wafer can be positioned;    a plasma torch included in the processing chamber, wherein the plasma torch is operable to etch back a surface of the wafer with the discharge from the plasma torch using reactive atom plasma processing; and    a translator operable to translate at least one of the wafer and the plasma torch.    
     
     
         17 . A tool for thinning a wafer, comprising: 
 a plasma processing chamber in which the wafer can be positioned;    a plasma torch included in the processing chamber, wherein the plasma torch is operable to thin the wafer by removing material from a surface of the wafer with the discharge from the plasma torch using reactive atom plasma processing; and    a translator operable to translate at least one of the wafer and the plasma torch.    
     
     
         18 . A tool for thinning a bonded wafer, comprising: 
 a plasma processing chamber in which the bonded wafer can be positioned;    a plasma torch included in the processing chamber, wherein the plasma torch is operable to thin the bonded wafer by removing material from an outer surface of the bonded wafer with the discharge from the plasma torch using reactive atom plasma processing; and    a translator operable to translate at least one of the bonded wafer and the plasma torch.    
     
     
         19 . A tool for shaping a surface of a workpiece at atmospheric pressure, comprising: 
 a plasma processing chamber in which the workpiece can be positioned;    a plasma torch included in the processing chamber, wherein the plasma torch is operable to simultaneously remove material from the surface of the workpiece and re-deposit the removed material back onto the surface of the workpiece at atmospheric pressure using reactive atom plasma processing; and    a translator operable to translate at least one of the workpiece and the plasma torch.    
     
     
         20 . A tool for shaping a surface of a workpiece, comprising: 
 means for positioning a workpiece in a plasma processing chamber including a plasma torch;    means for translating at least one of the workpiece and the plasma torch; and    means for performing a plurality of operations to process the surface of the workpiece using reactive atom plasma processing.