Plasma reactor for processing a workpiece with an array of plasma point sources

Abstract

A plasma source consisting of an array of plasma point sources that controls generation of charged particles and radicals spatially and temporally over a user defined region.

What is claimed is: 
     
         1 . A plasma reactor comprising:
 a processing chamber and a workpiece support in said processing chamber, said chamber comprising a lower ceiling facing said workpiece support;   an upper ceiling overlying and facing said lower ceiling and a gas distributor overlying said upper ceiling;   plural cavity walls defining plural cavities between said upper and lower ceilings, said gas distributor comprising plural gas flow paths to respective ones of said plural cavities;   plural outlet holes in said lower ceiling aligned with respective ones of said plural cavities;   respective power applicators adjacent respective ones of said plural cavities, a power source, plural power conductors coupled to respective ones of said power applicators, and a power distributor coupled between said power source and said plural power conductors.   
     
     
         2 . The plasma reactor of  claim 1  wherein said plural cavity walls comprise dielectric cavity walls. 
     
     
         3 . The plasma reactor of  claim 1  wherein said power source comprises an RF power generator and wherein each one of said respective power applicators is separated from an interior of a corresponding one of said plural cavities by the corresponding one of said plural cavity walls. 
     
     
         4 . The plasma reactor of  claim 3  wherein said power applicator comprises an electrode for capacitively coupling RF power into the corresponding one of said plural cavities. 
     
     
         5 . The plasma reactor of  claim 4  wherein said electrode surrounds a section of the corresponding one of said plural cavities. 
     
     
         6 . The plasma reactor of  claim 3  wherein said power applicator comprises a coil antenna for inductively coupling RF power into the corresponding one of said plural cavities. 
     
     
         7 . The plasma reactor of  claim 6  wherein said coil antenna comprises a conductor coiled around a section of the corresponding one of said plural cavities. 
     
     
         8 . The plasma reactor of  claim 1  wherein said power source is a D.C. power generator, each one of said power applicators comprises an electrode for D.C. discharge, and wherein each one of said cavity walls is configured to expose a corresponding electrode to an interior of a corresponding one of said plural cavities. 
     
     
         9 . The plasma reactor of  claim 1  wherein said power distributor comprises plural switches coupled between an output of said power source and respective ones of said power conductors. 
     
     
         10 . The plasma reactor of  claim 9  further comprising a processor controlling said plural switches individually in accordance with user-defined instructions. 
     
     
         11 . The plasma reactor of  claim 1  further comprising:
 a process gas source and a gas distributor comprising plural valves coupled between said process gas source and respective ones of said plural cavities. 
 
     
     
         12 . The plasma reactor of  claim 11  wherein said process gas source comprises plural gas sources of different gas species, wherein respective ones of said plural valves are coupled between respective ones of said plural gas sources and respective ones of said plural cavities. 
     
     
         13 . The plasma reactor of  claim 12  further comprising a processor controlling said plural valves individually in accordance with user-defined instructions. 
     
     
         14 . The plasma reactor of  claim 9  further comprising:
 a process gas source and a gas distributor comprising plural valves coupled between said process gas source and respective ones of said plural cavities. 
 
     
     
         15 . The plasma reactor of  claim 14  wherein said process gas source comprises plural gas sources of different gas species, wherein respective ones of said plural valves are coupled between respective ones of said plural gas sources and respective ones of said plural cavities. 
     
     
         16 . The plasma reactor of  claim 15  further comprising a processor controlling said plural valves individually and controlling said plural switches individually in accordance with user-defined instructions. 
     
     
         17 . The plasma reactor of  claim 1  further comprising a remote plasma source coupled to deliver plasma by-products to said plural cavities. 
     
     
         18 . The plasma reactor of  claim 1  wherein said processing chamber further comprises a cylindrical side wall below said lower ceiling, said reactor further comprising an inductively coupled plasma source comprising a coil antenna wound around said cylindrical side wall and an RF power generator coupled to said coil antenna through an impedance match. 
     
     
         19 . A plasma reactor comprising:
 a processing chamber and a workpiece support in said processing chamber;   a gas distributor overlying said workpiece support;   plural cavity walls defining plural cavities underlying said gas distributor, said gas distributor comprising plural gas flow paths to respective ones of said plural cavities;   respective power applicators adjacent respective ones of said plural cavities, a power source, plural power conductors coupled to respective ones of said power applicators, and a power distributor coupled between said power source and said plural power conductors; and   a process gas source and a gas distributor comprising plural valves coupled between said process gas source and respective ones of said plural cavities.   
     
     
         20 . A method of processing a workpiece in a plasma reactor comprising an array of plasma point sources distributed over a surface of the workpiece, comprising:
 performing a plasma process on the workpiece;   observing a non-uniformity in a spatial distribution of process rate across the surface of the workpiece; and   reducing said non-uniformity by performing at least one of:
 (a) adjusting an apportionment of plasma source power levels among said array of plasma point sources, or 
 (b) adjusting an apportionment of gas flows among said array of plasma point sources.