Method and apparatus for cleaning a cvd chamber

Abstract

The present invention is a method and apparatus for cleaning a chemical vapor deposition (CVD) chamber using cleaning gas energized to a plasma in a gas mixing volume separated by an electrode from a reaction volume of the chamber. In one embodiment, a source of RF power is coupled to a lid of the chamber, while a switch is used to couple a showerhead to ground terminals or the source of RF power.

What is claimed is: 
     
         1 . A semiconductor processing chamber, comprising:
 a substrate support;   a blocking plate;   a gas distribution plate between the substrate support and the blocking plate and coupled to the blocking plate, the gas distribution plate defining a gas mixing volume between the gas distribution plate and the blocking plate and a reaction volume between the gas distribution plate and the substrate support;   an RF source; and   a switch with a first position that couples the RF source to the gas distribution plate and the blocking plate and a second position that couples the RF source to the gas distribution plate and the substrate support.   
     
     
         2 . The semiconductor processing chamber of  claim 1 , wherein the gas distribution plate is electrically isolated from the substrate support and the blocking plate. 
     
     
         3 . The semiconductor processing chamber of  claim 2 , wherein the switch is a double-throw switch having a common contact coupled to the gas distribution plate and selectable contacts coupled to the blocking plate and the substrate support, respectively. 
     
     
         4 . The semiconductor processing chamber of  claim 3 , further comprising a source of nitrogen trifluoride coupled to the gas mixing volume. 
     
     
         5 . The semiconductor processing chamber of  claim 4 , further comprising a conductive sidewall. 
     
     
         6 . The semiconductor processing chamber of  claim 5 , wherein the substrate support comprises a heater. 
     
     
         7 . The semiconductor processing chamber of  claim 6 , wherein the conductive sidewall is grounded. 
     
     
         8 . The semiconductor processing chamber of  claim 1 , further comprising a source of nitrogen trifluoride coupled to the gas mixing volume, wherein the substrate support comprises a heater and the gas distribution plate is electrically isolated from the substrate support and the blocking plate. 
     
     
         9 . The semiconductor processing chamber of  claim 8 , further comprising an actuator coupled to the switch. 
     
     
         10 . A semiconductor processing chamber, comprising:
 a vacuum vessel comprising a sidewall and a lining;   a substrate support disposed within the vacuum vessel;   a lid coupled to the vacuum vessel, the lid comprising:
 a blocking plate; and 
 a gas distribution plate between the substrate support and the blocking plate, and defining a gas mixing volume between the gas distribution plate and the blocking plate and a reaction volume between the gas distribution plate and the substrate support; 
   an RF source; and   a switch with a first position that couples the RF source to the gas distribution plate and the blocking plate and a second position that couples the RF source to the gas distribution plate and the substrate support.   
     
     
         11 . The semiconductor processing chamber of  claim 10 , further comprising electrical isolators disposed between the gas distribution plate and the substrate support and between the gas distribution plate and the blocking plate. 
     
     
         12 . The semiconductor processing chamber of  claim 11 , wherein the switch is a double-throw switch having a common contact coupled to the gas distribution plate and selectable contacts coupled to the blocking plate and the substrate support, respectively. 
     
     
         13 . The semiconductor processing chamber of  claim 12 , wherein the substrate support comprises a heater. 
     
     
         14 . The semiconductor processing chamber of  claim 13 , further comprising an actuator coupled to the switch. 
     
     
         15 . The semiconductor processing chamber of  claim 14 , further comprising a source of nitrogen trifluoride fluidly coupled to the gas mixing volume. 
     
     
         16 . The semiconductor processing chamber of  claim 15 , wherein the sidewall is grounded. 
     
     
         17 . The semiconductor processing chamber of  claim 10 , further comprising an actuator coupled to the switch and a source of nitrogen trifluoride fluidly coupled to the gas mixing volume, wherein the switch is a double-throw switch having a common contact coupled to the gas distribution plate and selectable contacts coupled to the blocking plate and the substrate support, respectively. 
     
     
         18 . A semiconductor processing chamber, comprising:
 a vacuum vessel comprising a grounded sidewall and a lining;   a heated substrate support disposed within the vacuum vessel;   a lid coupled to the vacuum vessel, the lid comprising:
 a blocking plate; and 
 a gas distribution plate between the substrate support and the blocking plate, and defining a gas mixing volume between the gas distribution plate and the blocking plate and a reaction volume between the gas distribution plate and the substrate support; 
   a source of nitrogen trifluoride fluidly coupled to the gas mixing volume; and   an RF source coupled to the gas distribution plate, the blocking plate, and the substrate support by a switch with a first position that couples the RF source to the gas distribution plate and the blocking plate and a second position that couples the RF source to the gas distribution plate and the substrate support.   
     
     
         19 . The semiconductor processing chamber of  claim 18 , further comprising an actuator coupled to the switch, wherein the switch is a double-throw switch having a common contact coupled to the gas distribution plate and selectable contacts coupled to the blocking plate and the substrate support, respectively.