Use of enhanced turbomolecular pump for gapfill deposition using high flows of low-mass fluent gas

Abstract

High flows of low-mass fluent gases are used in an HDP-CVD process for gapfill deposition of a silicon oxide film. An enhanced turbomolecular pump that provides a large compression ratio for such low-mass fluent gases permits pressures to be maintained at relatively low levels in a substrate processing chamber, thereby improving the gapfill characteristics.

1 . A substrate processing system comprising: 
 a housing defining a substrate processing chamber;    a substrate holder configured to hold a substrate within the substrate processing chamber during substrate processing;    a gas-delivery system configured to introduce gases into the substrate processing chamber;    a high-density plasma generating system operatively coupled to the substrate processing chamber to generate a plasma having at least 10 11  ions/cm 3  from gases in the substrate processing chamber; and    a pressure-control system for maintaining a selected pressure within the substrate processing chamber, the pressure-control system including a pump in fluid communication with an outlet of the substrate processing chamber and providing a compression ratio greater than 10 5  for a gas of molecules having an average molecular mass less than 10 atomic mass units.    
   
   
       2 . The substrate processing system recited in  claim 1  wherein the pump is a turbomolecular pump.  
   
   
       3 . The substrate processing system recited in  claim 1  wherein the pump provides a compression ratio for H 2  between 10 5  and 10 6 .  
   
   
       4 . The substrate processing system recited in  claim 1  wherein the pump provides a compression ratio for He between 10 6  and 10 7 .  
   
   
       5 . The substrate processing system recited in  claim 1  wherein the pump provides a pumping speed that exceeds 2800 L/s for the gas of molecules having an average molecular mass less than 10 atomic mass units.  
   
   
       6 . The substrate processing system recited in  claim 5  wherein the pumping speed is between 2800 and 3500 L/s for a gas selected from the group consisting of H 2  and He.