Semiconductor processing with a remote plasma source for self-cleaning

Abstract

A plasma CVD device includes a reaction chamber, a remote plasma discharge chamber that is provided remotely from the reaction chamber, and piping that links the reaction chamber and the remote plasma discharge chamber. The remote plasma discharge chamber activates cleaning gas by plasma discharge energy, and the activated cleaning gas is introduced into the inside of the reaction chamber through the piping and changes solid substances that adhere to the inside of the reaction chamber in consequence of film formation, to gaseous substances, thereby cleaning the inside of the reaction chamber. The device is characterized by at least one of the following: (a) the remote plasma discharge chamber generates active species using radio frequency oscillating output energy of a preselected frequency; (b) the piping is made of materials that are not corroded by the active species; or (c) the piping is provided with a through-flow type valve.

We claim:  
     
         1 . A method of cleaning a chemical vapor deposition (CVD) reaction chamber with cleaning gas provided through a remote plasma discharge chamber, comprising: 
 dissociating cleaning gas within the remote plasma discharge chamber by applying energy with a power of less than about 3,000 W;    supplying activated species from the remote plasma discharge chamber to the reaction chamber through a piping; and    removing adhered deposits from CVD reactions on a wall of the reaction chamber at a rate of greater than or equal to about 2.0 microns/minute.    
     
     
         2 . The method of  claim 1 , wherein removing adhered deposits comprises removing adhered silicon nitride deposits.  
     
     
         3 . The method of  claim 1 , wherein the cleaning gas comprises fluorine-containing gas and the activated species comprises fluorine active species.  
     
     
         4 . The method of  claim 1 , wherein the applied energy has a frequency between about 300 kHz and 500 kHz.  
     
     
         5 . The method of  claim 1 , wherein supplying activated species comprises flowing NF 3  through the remote plasma discharge chamber at a rate between about 0.5 slm and 1.5 slm.  
     
     
         6 . A method of cleaning a chemical vapor deposition (CVD) reaction chamber with cleaning gas provided through a remote plasma discharge chamber, comprising: 
 forming a plasma with active species by applying energy with a power of less than about 3,000 W to a cleaning gas within the remote plasma discharge chamber;    transporting the active species from the remote plasma discharge chamber to the reaction chamber through a piping; and    removing adhered silicon nitride deposits from CVD reactions on a wall of the reaction chamber at a rate of greater than or equal to about 2.0 microns/minute.    
     
     
         7 . The method of  claim 6 , wherein the applied energy has a frequency between about 300 kHz and 500 kHz.  
     
     
         8 . The method of  claim 6 , wherein supplying activated species comprises flowing NF 3  through the remote plasma discharge chamber at a rate between about 0.5 slm and 1.5 slm.  
     
     
         9 . The method of  claim 6 , further comprising opening a valve on the piping after conducting a CVD reaction and prior to supplying activated species.  
     
     
         10 . The method of  claim 9 , wherein opening a valve comprises withdrawing a sealing element completely from a path to form an opening substantially as wide as internal surfaces of the piping.  
     
     
         11 . The method of  claim 9 , further comprising closing the valve after removing the adhered silicon nitride deposits.  
     
     
         12 . A method of removing deposits from a reaction chamber of a chemical vapor deposition device, the method comprising: 
 supplying a cleaning gas containing fluorine to a remote plasma discharge chamber;    applying an energy in the remote plasma discharge chamber of less than 3000 W to the cleaning gas to form a plasma with fluorine active species;    transporting the fluorine active species from the remote plasma discharge chamber to the reaction chamber through a piping; and    removing adhered deposits from CVD reactions on a wall of the reaction chamber at a rate of greater than or equal to about 2.0 microns/minute.    
     
     
         13 . The method of  claim 12 , wherein removing adhered deposits on the wall of the reaction chamber comprises removing adhered silicon nitride deposits.  
     
     
         14 . The method of  claim 12 , wherein removing adhered deposits on the wall of the reaction chamber comprises removing adhered silicon oxide deposits.  
     
     
         15 . The method of  claim 12 , wherein removing adhered deposits on the wall of the reaction chamber comprises removing adhered tungsten deposits.  
     
     
         16 . The method of  claim 12 , wherein supplying the cleaning gas comprises supplying carbon tetrafluoride (CF 4 ).  
     
     
         17 . The method of  claim 12 , wherein supplying the cleaning gas comprises supplying nitrogen trifluoride (NF 3 ).  
     
     
         18 . The method of  claim 12 , wherein applying an energy comprises applying an energy of between about 2,500 W and 3,000 W.  
     
     
         19 . The method of  claim 12 , wherein the applied energy has a frequency between about 300 kHz and 500 kHz.  
     
     
         20 . The method of  claim 12 , further comprising opening a valve on the piping after conducting a CVD reaction and prior to supplying activated species.  
     
     
         21 . The method of  claim 20 , wherein opening a valve comprises withdrawing a sealing element completely from a path to form an opening substantially as wide as internal surfaces of the piping.  
     
     
         22 . The method of  claim 20 , further comprising closing the valve after removing the adhered silicon nitride deposits.