Gap fill using carbon-based films

Abstract

Provided herein are methods of filling gaps using high density plasma chemical vapor deposition (HDP CVD). According to various implementations, carbon-containing films such as amorphous carbon and amorphous carbide films are deposited by HDP CVD into gaps on substrates to fill the gaps. The methods may involve using high hydrogen-content process gasses during HDP CVD deposition to provide bottom-up fill. Also provided are related apparatus.

1 . A method comprising:
 introducing a process gas to a high density plasma chemical vapor deposition (HDP CVD) chamber that houses a substrate having a gap, wherein the process gas includes a hydrocarbon reactant and has a H:C ratio of at least 4:1; and   filling the gap with a carbon-based film by an HDP CVD reaction of the process gas.   
     
     
         2 . The method of  claim 1 , wherein the gap is filled in a single deposition operation with no intervening etch operations. 
     
     
         3 . The method of  claim 1 , wherein the carbon-based film is an amorphous carbon (a-C) film. 
     
     
         4 . The method of  claim 1 , wherein the carbon-based film is an amorphous carbide film. 
     
     
         5 . The method of  claim 4 , wherein the carbon-based film is a doped or undoped amorphous silicon carbide film. 
     
     
         6 . The method of  claim 5 , wherein the process gas includes a silicon-containing reactant having a H:Si ratio of at least 4. 
     
     
         7 . The method of  claim 1 , wherein the hydrocarbon reactant has a H:C ratio of at least 3:1. 
     
     
         8 . The method of  claim 7 , wherein the hydrocarbon reactant has a H:C ratio of at least 4:1. 
     
     
         9 . The method of  claim 1 , wherein the process gas includes molecular hydrogen (H 2 ). 
     
     
         10 . The method of  claim 1 , further comprising generating a plasma including hydrogen radicals. 
     
     
         11 . The method of  claim 1 , wherein the filling the gap comprises a hydrogen radical etch at the top of the gap during the HDP CVD reaction. 
     
     
         12 . The method of  claim 1 , wherein filling the gap with a carbon-based film comprises two or more deposition stages and one or more intervening etch operations. 
     
     
         13 . The method of  claim 12 , wherein the one or more intervening etch operations are hydrogen-based etches. 
     
     
         14 . An apparatus comprising:
 a plasma generator;   chamber comprising a pedestal;   one or more inlets to the chamber; and   a controller comprising machine-readable instructions for:   inletting a process gas comprising a hydrocarbon reactant, wherein the process gas has a H:C ratio of at least 4:1; and   generating a high density plasma in the chamber to thereby fill a gap on a substrate in the chamber.   
     
     
         15 . The apparatus of  claim 14 , wherein the hydrocarbon reactant has a H:C ratio of at least 3:1. 
     
     
         16 . The apparatus of  claim 14 , wherein the hydrocarbon reactant has a H:C ratio of at least 4:1. 
     
     
         17 . The apparatus of  claim 14 , wherein the process gas includes a silicon-containing reactant having a H:Si ratio of at least 4. 
     
     
         18 . The apparatus of  claim 14 , wherein the process gas includes molecular hydrogen (H 2 ).