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.

1 . A chamber for processing semiconductor substrates, comprising:
 a chamber wall defining an enclosure;   a plurality of electrodes, each electrically isolated from at least one of the other electrodes, at least one of the electrodes disposed inside the enclosure; and   a switch with at least two positions, each position selectably coupling a different pair of the electrodes together.   
   
   
       2 . The chamber of  claim 1 , wherein the chamber is a chamber for performing a chemical vapor deposition process or a plasma enhanced chemical vapor deposition process. 
   
   
       3 . The chamber of  claim 1 , wherein at least one of the plurality of electrodes is coupled to a ground reference of the chamber. 
   
   
       4 . The chamber of  claim 1 , wherein the plurality of electrodes comprises a blocking plate electrode and a showerhead electrode. 
   
   
       5 . The system of  claim 4 , wherein the showerhead electrode is electrically isolated using isolators formed from ceramic or polyimide. 
   
   
       6 . The system of  claim 5 , wherein the isolators are formed from Al 2 O 3 . 
   
   
       7 . The system of  claim 1 , wherein the plurality of electrodes comprises a showerhead electrode and a substrate support electrode, and the switch couples the showerhead electrode to the substrate support electrode during plasma cleaning the chamber. 
   
   
       8 . The system of  claim 1 , wherein the plurality of electrodes comprises a showerhead electrode and a blocking plate electrode, and the switch couples the showerhead electrode to the blocking plate electrode during processing the substrate. 
   
   
       9 . The system of  claim 1 , wherein the switch is a double-throw switch having a common terminal and two or more selectable terminals. 
   
   
       10 . The system of  claim 1 , wherein the switch further comprises an actuator to operate the switch. 
   
   
       11 . A semiconductor substrate processing system comprising a chamber for processing a substrate, said chamber comprising:
 a plurality of electrodes, each electrically isolated from at least one of the other electrodes, at least one of the electrodes disposed inside the enclosure, and at least one of the electrodes coupled to a source of radio-frequency power having a frequency between about 50 kHz and about 13.56 MHz and power level of at least about 500 W; and   a switch with at least two positions, each position selectably coupling a different pair of the electrodes together.   
   
   
       12 . The system of  claim 11 , wherein at least one of the plurality of electrodes is a showerhead electrode electrically isolated using isolators from ceramic or polyimide. 
   
   
       13 . The system of  claim 12 , wherein the isolators are formed from Al 2 O 3 . 
   
   
       14 . The system of  claim 11 , wherein the plurality of electrodes comprises a showerhead electrode and a substrate support electrode, and the switch couples the showerhead electrode to the substrate support electrode during plasma cleaning the chamber. 
   
   
       15 . The system of  claim 11 , wherein the plurality of electrodes comprises a showerhead electrode and a blocking plate electrode, and the switch couples the showerhead electrode to the blocking plate electrode during processing the substrate. 
   
   
       16 . The system of  claim 11 , wherein the switch is a double-throw switch having a common terminal and two or more selectable terminals. 
   
   
       17 . The system of  claim 11 , wherein the switch further comprises an actuator to operate the switch.