Methods of dry stripping boron-carbon films

Abstract

Embodiments of the invention generally relate to methods of dry stripping boron-carbon films. In one embodiment, alternating plasmas of hydrogen and oxygen are used to remove a boron-carbon film. In another embodiment, co-flowed oxygen and hydrogen plasma is used to remove a boron-carbon containing film. A nitrous oxide plasma may be used in addition to or as an alternative to either of the above oxygen plasmas. In another embodiment, a plasma generated from water vapor is used to remove a boron-carbon film. The boron-carbon removal processes may also include an optional polymer removal process prior to removal of the boron-carbon films. The polymer removal process includes exposing the boron-carbon film to NF 3 to remove from the surface of the boron-carbon film any carbon-based polymers generated during a substrate etching process.

1 . A method for stripping a film from a substrate, comprising:
 positioning a substrate having a film thereon in a chamber, the film comprising boron and carbon;   exposing the film to a water vapor plasma at a pressure above 50 Torr to generate one or more volatile compounds from the boron and carbon; and   exhausting the one or more volatile compounds from the chamber.   
     
     
         2 . The method of  claim 1 , wherein an atomic ratio of boron to carbon in the film is within a range of about 1:1 to about 3:1. 
     
     
         3 . The method of  claim 1 , wherein the water vapor plasma is formed from a precursor gas comprising water vapor and a carrier gas, and a flow rate of the precursor gas is at least about 7 sLm. 
     
     
         4 . The method of  claim 2 , wherein the plasma is maintained at a power input of at least 2,000 watts and spacing less than 200 mils. 
     
     
         5 . The method of  claim 4 , wherein the water vapor plasma comprises excess hydrogen. 
     
     
         6 . A method of removing a boron-carbon film, comprising:
 exposing the boron-carbon film to a water vapor plasma containing excess hydrogen in a processing chamber;   maintaining a pressure in the processing chamber above 50 Torr;   reacting oxygen in the water vapor plasma with carbon in the boron-carbon film to form volatile carbon species;   reacting hydrogen in the water vapor plasma with boron in the boron-carbon film to form volatile boron species; and   removing the volatile carbon species and the volatile boron species from the processing chamber.   
     
     
         7 . The method of  claim 6 , wherein the water vapor plasma is formed from a precursor gas comprising the excess hydrogen, and the precursor gas is provided to the processing chamber at a flow rate of at least 7 sLm. 
     
     
         8 . The method of  claim 7 , wherein the water vapor plasma is formed by applying at least 2,000 watts of power to the precursor gas.