Systems for modulating step coverage during conformal film deposition

Abstract

A system for processing a substrate include a processing chamber including a pedestal to support a substrate and a controller configured to a) supply precursor to the processing chamber; b) purge the processing chamber; c) perform radio frequency (RF) plasma activation; d) purge the processing chamber; and e) prior to purging the processing chamber in at least one of (b) or (d), set a vacuum pressure of the processing chamber to a first predetermined pressure that is less than a vacuum pressure during at least one of (a) or (c) for a first predetermined period.

What is claimed is: 
     
         1 . A system for processing a substrate, comprising:
 a processing chamber including a pedestal to support a substrate; and   a controller configured to:
 a) supply precursor to the processing chamber; 
 b) purge the processing chamber; 
 c) perform radio frequency (RF) plasma activation; 
 d) purge the processing chamber; and 
 e) prior to purging the processing chamber in at least one of (b) or (d), set a vacuum pressure of the processing chamber to a first predetermined pressure that is less than a vacuum pressure during the at least one of (a) or (c) for a first predetermined period. 
   
     
     
         2 . The system of  claim 1 , wherein the first predetermined period is greater than or equal to 0.5 seconds and less than or equal to 5 seconds. 
     
     
         3 . The system of  claim 1 , wherein the controller is configured to perform (e) before (b) and (d). 
     
     
         4 . The system of  claim 1 , wherein the controller is configured to perform (e) before (d), and wherein the controller is configured to wait a predetermined period after (c) and before (e). 
     
     
         5 . The system of  claim 1 , wherein the controller is configured to flow oxidants during (e). 
     
     
         6 . The system of  claim 5 , wherein the oxidants comprise one of molecular oxygen and nitrous oxide. 
     
     
         7 . The system of  claim 1 , wherein the RF plasma activation comprises RF plasma oxidation. 
     
     
         8 . The system of  claim 1 , wherein the controller is configured to set vacuum pressure in the processing chamber greater than or equal to 1 Torr and less than or equal to 15 Torr during (a), (b), (c) and (d). 
     
     
         9 . The system of  claim 8 , wherein the controller is configured to set vacuum pressure in the processing chamber during (a), (b), (c) and (d) to be approximately isobaric. 
     
     
         10 . The system of  claim 8 , wherein the controller is configured to set vacuum pressure in the processing chamber during (f) greater than or equal to 5 mTorr and less than or equal to 2 Torr. 
     
     
         11 . The system of  claim 1 , wherein the controller is configured to set vacuum pressure in the processing chamber greater than or equal to 3 Torr and less than or equal to 8 Torr during (a), (b), (c) and (d). 
     
     
         12 . The system of  claim 11 , wherein the controller is configured to set vacuum pressure in the processing chamber during (a), (b), (c) and (d) to be approximately isobaric. 
     
     
         13 . The system of  claim 11 , wherein the controller is configured to set vacuum pressure in the processing chamber during (e) greater than or equal to 5 mTorr and less than or equal to 500 mTorr. 
     
     
         14 . The system of  claim 1 , wherein plasma-enhanced chemical vapor deposition is performed in the processing chamber. 
     
     
         15 . The system of  claim 1 , wherein performing plasma-enhanced atomic layer deposition is performed in the processing chamber.