Plasma cleaning of deposition chamber residues using duo-step wafer-less auto clean method

Abstract

A method involving plasma cleaning of deposit residues in process chamber using duo-step wafer-less auto clean method is detailed. Specifically, the method involves cleaning the processing chamber by flowing a first gaseous composition with at least about 75% of fluorine-containing compound of the formula X y F z , into a processing chamber and then forming a first etchant plasma which removes silicon and silicon based byproducts from the interior surfaces of the processing chamber. The method then involves flowing a second gaseous composition into the processing chamber with a composition of at least about 50% O 2 and forming a plasma from the second gaseous composition to provide a second etchant plasma which removes carbon and carbon based byproducts from the interior surfaces of the processing chamber. A system configured to execute the two step cleaning process is also provided.

1 . A plasma processing system for executing a two step in-situ cleaning process, comprising: 
 a processing chamber having: 
 a gas inlet for introducing a first cleaning gas and a second cleaning gas, the first cleaning gas optimized to remove silicon based byproducts deposited on inner surfaces of the processing chamber, the second cleaning gas optimized to remove carbon based byproducts on the inner surfaces of the processing chamber; and  
 a top electrode for creating a first plasma from the first cleaning gas to perform a first step of the in-situ cleaning process and then a second plasma from the second cleaning gas upon completion of the first step;  
   a variable conductance meter for controlling a pressure inside the processing chamber independently of a flow rate of the process gases, the variable conductance meter positioned on an outlet of the processing chamber;    an optical emission spectrometer (OES) for detecting an endpoint for each step of the two step in-situ cleaning process performed in the processing chamber, the OES in communication with the processing chamber; and    a pumping system for evacuating the processing chamber between each step of the two step cleaning process.    
   
   
       2 . The plasma processing system of  claim 1 , wherein the first cleaning gas is a fluorine containing compound and the second cleaning gas is an oxygen containing compound.  
   
   
       3 . The plasma processing system of  claim 1 , wherein the OES monitor is configured to detect wavelengths corresponding to silicon based byproducts for the first step of the in-situ cleaning process and carbon based byproducts for a second step of the in-situ cleaning process.  
   
   
       4 . The plasma processing system of  claim 1 , wherein the two step cleaning process is performed after each processing operation in the processing chamber.  
   
   
       5 . A plasma processing system for executing a two step in-situ cleaning process, comprising: 
 a processing chamber having a gas inlet for introducing a first cleaning gas and a second cleaning gas flowing a first gaseous composition into a processing chamber, the first cleaning gas including at least about 75% of a fluorine-containing compound of the formula X y F z ;    a controller having process instructions causing the two step in-situ cleaning process to proceed by: 
 forming a plasma from the first cleaning gas to provide a first etchant plasma which removes silicon and silicon based compounds from interior surfaces of the processing chamber;  
 flowing the second cleaning gas into a processing chamber after removal of the first gaseous composition, the second cleaning gas including at least about 50% O 2 ; and  
 forming a plasma from the second gaseous composition to provide a second etchant plasma which removes carbon and carbon based compounds from interior surfaces of the processing chamber.  
   
   
   
       6 . The plasma processing system of  claim 5 , further comprising: 
 a top electrode for creating a first plasma from the first cleaning gas to perform a first step of the in-situ cleaning process and then a second plasma from the second cleaning gas upon completion of the first step;    a variable conductance meter for controlling a pressure inside the processing chamber independently of a flow rate of the process gases, the variable conductance meter positioned on an outlet of the processing chamber;    an optical emission spectrometer (OES) for detecting an endpoint for each step of the two step in-situ cleaning process performed in the processing chamber, the OES in communication with the processing chamber; and    a pumping system for evacuating the processing chamber between each step of the two step cleaning process.    
   
   
       7 . A plasma processing system for executing a two step in-situ cleaning process, comprising: 
 a processing chamber having a gas inlet for introducing a first process gas and a second process gas into a processing chamber, the first process gas including at least about 75% of a fluorine-containing compound of the formula X y F z ;    a controller having process instructions causing the two step in-situ cleaning process, the process instructions including,    process instructions for flowing the first process gas with a fluorine-containing compound of the formula X y F z , said fluorine-containing compound being optimized to remove silicon and silicon compounds;    process instructions for forming a plasma from said first process gas;    process instructions for flowing a second process gas containing oxygen upon removal of the first process gas, said second process gas being optimized to remove carbon based compounds and an optional fluorine-containing compound of the formula X y F z , said fluorine-containing compound being optimized to remove silicon and silicon compounds;    process instructions for forming a plasma from said second process gas;    process instructions for maintaining a pressure in the processing chamber between about 2 mTorr and about 100 mTorr; and    process instructions for monitoring said process for carbon-based compounds on interior surfaces of said processing chamber for reaching a predetermined level.    
   
   
       8 . The method of  claim 7  wherein the second etchant process gas is essentially oxygen and a flow rate of the process gas is about 100 standard cubic centimeters per minute.  
   
   
       9 . The method of  claim 7 , further including: 
 process instructions introducing the second process gas containing oxygen into the processing chamber at a flow rate between about 100 standard cubic centimeters per minute (sccm) and about 600 sccm; and    process instructions applying a TCP power between about 800 Watts and 1500 Watts.    
   
   
       10 . The method of  claim 9  wherein said second etchant process gas containing oxygen is at least about 90% O 2 .