Removing metal contamination from surfaces of a processing chamber

Abstract

A method for cleaning surfaces of a substrate processing chamber includes a) supplying a first gas selected from a group consisting of silicon tetrachloride (SiCU 4 ), carbon tetrachloride (CCI 4 ), a hydrocarbon (C x H y where x and y are integers) and molecular chlorine (CI 2 ), boron trichloride (BCI 3 ), and thienyl chloride (SOCI 2 ); b) striking plasma in the substrate processing chamber to etch the surfaces of the substrate processing chamber; c) extinguishing the plasma and evacuating the substrate processing chamber; d) supplying a second gas including fluorine species; e) striking plasma in the substrate processing chamber to etch the surfaces of the substrate processing chamber; and f) extinguishing the plasma and evacuating the substrate processing chamber.

What is claimed is: 
     
         1 . A method for cleaning surfaces of a substrate processing chamber, comprising:
 a) supplying a first gas selected from a group consisting of silicon tetrachloride (SiCl 4 ), carbon tetrachloride (CCl 4 ), a hydrocarbon (C x H y  where x and y are integers) and molecular chlorine (Cl 2 ), boron trichloride (BCl 3 ), and thionyl chloride (SOCl 2 );   b) striking plasma in the substrate processing chamber to etch the surfaces of the substrate processing chamber;   c) extinguishing the plasma and evacuating the substrate processing chamber;   d) supplying a second gas including fluorine species;   e) striking plasma in the substrate processing chamber to etch the surfaces of the substrate processing chamber; and   f) extinguishing the plasma and evacuating the substrate processing chamber.   
     
     
         2 . The method of  claim 1 , further comprising:
 g) repeating a) to c) and d) to f) N times, where N is an integer greater than zero.   
     
     
         3 . The method of  claim 1 , wherein the second gas is selected from a group consisting of nitrogen trifluoride (NF 3 ), sulfur hexafluoride (SF 6 ), and carbon tetrafluoride (CF 4 ). 
     
     
         4 . The method of  claim 2 , wherein a) to g) are performed without a substrate located on a substrate support in the substrate processing chamber. 
     
     
         5 . The method of  claim 2 , further comprising pre-coating the surfaces of the substrate processing chamber with a material selected from a group consisting of silicon (Si) and silicon oxide (SiO x ) after g). 
     
     
         6 . The method of  claim 1 , wherein a) to c) are performed after d) to f) during each of the N times. 
     
     
         7 . The method of  claim 1 , wherein a) to c) are performed before d) to f) during each of the N times. 
     
     
         8 . The method of  claim 2 , further comprising:
 prior to performing a) to g):
 pre-coating the surface of the substrate processing chamber with a material selected from a group consisting of silicon (Si) and silicon oxide (SiO x ); and 
 performing a substrate treatment; and 
   after g):
 pre-coating the surface of the substrate processing chamber with a material selected from a group consisting of silicon (Si) and silicon oxide (SiO x ); and 
 performing a substrate treatment. 
   
     
     
         9 . The method of  claim 8 , wherein the substrate treatment comprises etching. 
     
     
         10 . The method of  claim 9 , wherein the substrate includes tin (Sn) and wherein Sn contamination is less than 1e 10 /cm 2  after g). 
     
     
         11 . The method of  claim 1 , further comprising:
 controlling a first pressure in the substrate processing chamber during b) within a first pressure range; and   controlling a second pressure in the substrate processing chamber during e) within a second pressure range, wherein the first pressure range is less than the second pressure range.   
     
     
         12 . The method of  claim 11 , wherein the first pressure range is from 1 to 30 mT and wherein the second pressure range is from 30 to 150 mT. 
     
     
         13 . A substrate processing system for treating substrates, comprising:
 a processing chamber comprising chamber walls and a substrate support;   a gas delivery system to selectively deliver gases to the processing chamber;   a plasma generator to selectively generate plasma in the processing chamber; and   a controller configured to control the gas delivery system and the plasma generator to:
 a) supply a first gas selected from a group consisting of silicon tetrachloride (SiCl 4 ), carbon tetrachloride (CCl 4 ), a hydrocarbon (C x H y  where x and y are integers) and molecular chlorine (Cl 2 ), boron trichloride (BCl 3 ), and thionyl chloride (SOCl 2 ); 
 b) strike plasma in the substrate processing chamber to etch the surfaces of the substrate processing chamber; 
 c) extinguish the plasma and evacuate the substrate processing chamber; 
 d) supply a second gas including fluorine species; 
 e) strike plasma in the substrate processing chamber to etch the surfaces of the substrate processing chamber; and 
 f) extinguish the plasma and evacuate the substrate processing chamber. 
   
     
     
         14 . The substrate processing system of  claim 13 , wherein the controller is further configured to:
 g) repeat a) to c) and d) to f) N times, where N is an integer greater than zero.   
     
     
         15 . The substrate processing system of  claim 13 , wherein the second gas is selected from a group consisting of nitrogen trifluoride (NF 3 ), sulfur hexafluoride (SF 6 ), and carbon tetrafluoride (CF 4 ). 
     
     
         16 . The substrate processing system of  claim 14 , wherein the controller is configured to remove a substrate from the substrate support prior to performing a) to g). 
     
     
         17 . The substrate processing system of  claim 14 , wherein the controller is configured to pre-coat the surfaces of the substrate processing chamber with a material selected from a group consisting of silicon (Si) and silicon oxide (SiO x ) after g). 
     
     
         18 . The substrate processing system of  claim 13 , wherein the controller is configured to perform a) to c) after d) to f) during each of the N times. 
     
     
         19 . The substrate processing system of  claim 13 , wherein the controller is configured to perform a) to c) before d) to f) during each of the N times. 
     
     
         20 . The substrate processing system of  claim 14 , wherein the controller is configured to:
 prior to performing a) to g):
 pre-coat the surface of the substrate processing chamber with a material selected from a group consisting of silicon (Si) and silicon oxide (SiO x ); and 
 perform a substrate treatment; and 
   after g):
 pre-coat the surface of the substrate processing chamber with a material selected from a group consisting of silicon (Si) and silicon oxide (SiO x ); and 
 perform a substrate treatment. 
   
     
     
         21 . The substrate processing system of  claim 20 , wherein the substrate treatment comprises etching. 
     
     
         22 . The substrate processing system of  claim 21 , wherein the substrate includes tin (Sn) and wherein Sn contamination is less than 5e 9 /cm 2  after g). 
     
     
         23 . The substrate processing system of  claim 13 , wherein the controller is configured to:
 control a first pressure in the substrate processing chamber during b) to a first pressure range; and   control a second pressure in the substrate processing chamber during e) to a second pressure range, wherein the first pressure range is less than the second pressure range.   
     
     
         24 . The substrate processing system of  claim 23 , wherein the first pressure range is from 1 to 30 mT and wherein the second pressure range is from 30 to 100 mT.