Surface Smoothing of Workpieces

Abstract

Apparatus, systems, and methods for processing workpieces are provided. In one example implementation, a fluorine and oxygen plasma-based process can be used to smooth a roughened surface of a silicon and/or a silicon containing structure. The process can include generating species from a process gas using an inductive coupling element in a first chamber. The process can include introducing a fluorine containing gas and an oxygen containing gas with the species to create a mixture. The process can further include exposing the silicon and/or the silicon containing structure to the mixture such that the mixture at least partially etches a roughened portion to leave a smoother surface of the silicon and/or the silicon containing structure.

1 .- 15 . (canceled) 
     
     
         16 . A plasma processing apparatus for processing a workpiece, comprising:
 a processing chamber having a workpiece support, the workpiece support configured to support the workpiece during plasma processing, wherein the workpiece comprises a silicon containing layer, wherein a surface of the silicon containing layer comprises a roughened portion;   a plasma chamber separated from the processing chamber by a separation grid;   an inductive coupling element configured to induce a plasma using a process gas in the plasma chamber;   a first gas source injecting a fluorine containing gas;   a second gas source injecting an oxygen containing gas   wherein a mixture generated by mixing the fluorine containing gas and the oxygen containing gas with species generated in the plasma pass through the separation grid to at least partially etch the roughened portion to leave a smoother surface of the silicon containing layer.   
     
     
         17 . The plasma processing apparatus of  claim 16 , wherein the roughened portion comprises a concave area and a convex area, wherein the concave area is thicker than the convex area, the mixture at least partially etches the concave area more than the convex area to leave the smoother surface of the silicon containing layer. 
     
     
         18 . The plasma processing apparatus of  claim 16 , wherein a concentration of the fluorine containing gas in the oxygen containing gas is in the range of about 0.1% to about 5%. 
     
     
         19 . The plasma processing apparatus of  claim 16 , wherein the mixture at least partially oxidizes and at least partially etches the at least partially roughened portion simultaneously to leave the smoother surface. 
     
     
         20 . The plasma processing apparatus of  claim 16 , wherein the smoother surface comprises a material with a formula SiO x F y C z , wherein x, y and z are positive integers.