Low-k damage avoidance during bevel etch processing

Abstract

An apparatus for etching a bevel edge of a substrate includes a bevel etch chamber and a controller including non-transitory computer readable media. The computer readable media includes computer readable code for providing a cleaning gas comprising at least one of a CO 2 or CO, computer readable code for forming a cleaning plasma from the cleaning gas, and computer readable code for cleaning the bevel edge with the cleaning plasma, including computer readable code for placing the gas distribution plate at a close distance from a top surface of the substrate such that the cleaning plasma is not formed between the gas distribution plate and the substrate during the bevel edge cleaning, the bevel edge exposed to the cleaning plasma including at least an edge portion of a top surface at an edge of the substrate.

What is claimed is: 
     
         1 . An apparatus for etching a bevel edge of a substrate, comprising:
 a bevel etch chamber, comprising:
 a chamber wall forming a bevel etch chamber enclosure; 
 a substrate support for supporting a substrate within the bevel etch chamber enclosure, wherein the substrate support has a diameter smaller than a diameter of the substrate; 
 a pressure regulator for regulating the pressure in the bevel etch chamber enclosure; 
 at least one electrode for providing power to the bevel etch chamber enclosure for sustaining a plasma; 
 a gas distribution plate; 
 a gas inlet for providing gas into the plasma processing chamber enclosure; and 
 a gas outlet for exhausting gas from the bevel etch chamber enclosure; 
   a gas source in fluid connection with the gas inlet, comprising a cleaning gas comprising at least one of a CO 2  or CO; and   a controller controllably connected to the gas source, the gas distribution plate, and the at least one electrode, comprising:
 at least one processor; and 
 non-transitory computer readable media comprising:
 computer readable code for providing a cleaning gas comprising at least one of a CO 2  or CO; 
 computer readable code for forming a cleaning plasma from the cleaning gas; and 
 computer readable code for cleaning the bevel edge with the cleaning plasma, including computer readable code for placing the gas distribution plate at a close distance from a top surface of the substrate such that the cleaning plasma is not formed between the gas distribution plate and the substrate during the bevel edge cleaning, the bevel edge exposed to the cleaning plasma including at least an edge portion of a top surface at an edge of the substrate. 
 
   
     
     
         2 . The apparatus of  claim 1 , wherein the computer readable code for cleaning the bevel edge further comprises:
 computer readable code for flowing the cleaning plasma only from the gas distribution plate over the top surface of the substrate.   
     
     
         3 . The apparatus of  claim 1 , wherein the at least one electrode comprises a top electrode and a bottom electrode,
 and wherein the computer readable code for cleaning the bevel edge further comprises:
 computer readable code for moving at least one of the top electrode and the bottom electrode toward the other, forcing the cleaning plasma to sides of the plasma processing chamber so as to expose the bevel edge to the cleaning plasma. 
   
     
     
         4 . The apparatus of  claim 1 , wherein the bevel edge exposed to the cleaning plasma further includes an edge portion of a bottom surface at the edge of the substrate. 
     
     
         5 . The apparatus of  claim 1 , wherein the computer readable code for cleaning the bevel edge further comprises:
 computer readable code for keeping the substrate support and the gas distribution plate electrically floating during the bevel edge cleaning.   
     
     
         6 . The apparatus of  claim 1 , wherein the at least one electrode comprises:
 a top edge electrode and a bottom edge electrode, the top edge electrode surrounding an edge of the gas distribution plate and the bottom edge electrode surrounding an edge of the substrate support,   and wherein the computer readable code for forming the cleaning plasma comprises:   computer readable code for forming the cleaning plasma between the top edge electrode and the bottom edge electrode.   
     
     
         7 . The apparatus of  claim 1 , wherein the cleaning gas further comprises hydrocarbons. 
     
     
         8 . The apparatus of  claim 1 , wherein the cleaning gas further comprises H 2 .