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.

We claim: 
     
         1 . A method for stripping a film from a substrate, comprising:
 positioning a substrate having the film thereon in a chamber, the film comprising boron and carbon;   providing an oxygen-containing plasma in the chamber;   exposing the film to the oxygen-containing plasma to generate one or more volatile compounds from the boron and carbon;   providing an hydrogen-containing plasma in the chamber;   exposing the film to the hydrogen-containing plasma to generate one or more volatile compounds from the boron and carbon;   exhausting the oxygen-containing plasma from the chamber while continuing to provide the hydrogen-containing plasma; and   exhausting at least one of 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 , further comprising exposing the film to fluoride ions or radicals and oxygen ions or radicals to remove carbon-based polymers from a surface thereof prior to exposing the film to the oxygen plasma and the hydrogen plasma. 
     
     
         4 . The method of  claim 1 , wherein the oxygen-containing plasma is formed from an oxygen-containing gas comprising O 2 , N 2 O, CO 2 , NO, or NO 2 , and the hydrogen-containing plasma is formed from a hydrogen-containing gas comprising H 2  or NH 3 . 
     
     
         5 . The method of  claim 4 , wherein the hydrogen-containing gas has a flow rate between about 500 SCCM and about 10,000 SCCM and the oxygen-containing gas has a flow rate between about 250 SCCM and about 5000 SCCM. 
     
     
         6 . The method of  claim 4 , wherein oxygen-containing and the hydrogen-containing plasma are each generated by applying about 1000 watts to about 3000 watts of power from an RF plasma generator. 
     
     
         7 . The method of  claim 4 , wherein the pressure within the chamber is within a range of about 5 Torr to about 100 Torr and the substrate is maintained at a temperature within a range of about 200° C. to about 400° C. 
     
     
         8 . The method of  claim 1 , wherein exhausting at least one of the one or more volatile compounds from the chamber is performed before and after exhausting the oxygen-containing plasma from the chamber while continuing to provide the hydrogen-containing plasma. 
     
     
         9 . A method for stripping a film from a substrate, comprising:
 positioning a substrate having the film thereon in a chamber, the film comprising boron and carbon;   providing an oxygen-containing plasma in the chamber;   exposing the film to the oxygen-containing plasma to generate one or more volatile compounds from the boron and carbon;   providing a hydrogen-containing plasma in the chamber;   exposing the film to the hydrogen-containing plasma to generate one or more volatile compounds from the boron and carbon;   exhausting the oxygen-containing plasma from the chamber while continuing to provide the hydrogen-containing plasma;   exhausting at least one of the one or more volatile compounds from the chamber;   repeating providing an oxygen-containing plasma, exposing the film to the oxygen-containing plasma, providing a hydrogen-containing plasma, exposing the film to the hydrogen-containing plasma while continuing to provide the hydrogen-containing plasma, and exhausting at least one of the one or more volatile compounds.   
     
     
         10 . The method of  claim 9 , wherein an atomic ratio of boron to carbon in the boron-carbon film is within a range of about 1:1 to about 3:1. 
     
     
         11 . The method of  claim 10 , wherein the substrate is disposed on a substrate support in the chamber opposite a face plate of the chamber, the oxygen-containing plasma and hydrogen-containing plasma are each maintained at a power input of at least 2,000 watts, and a spacing between the substrate and the face plate is maintained at less than 200 mils. 
     
     
         12 . The method of  claim 9 , wherein the pressure within the chamber is greater than about 5 Torr, and the substrate is positioned less than about 600 mils from a surface of a face plate located within the chamber. 
     
     
         13 . The method of  claim 9 , wherein the oxygen-containing plasma is formed from an oxygen-containing gas comprising O 2 , N 2 O, CO 2 , NO, or NO 2 , and wherein the hydrogen-containing plasma is formed from a hydrogen-containing gas comprising H 2  or NH 3 . 
     
     
         14 . The method of  claim 9 , wherein exhausting at least one of the one or more volatile compounds from the chamber is performed before and after exhausting the oxygen-containing plasma from the chamber while continuing to provide the hydrogen-containing plasma. 
     
     
         15 . A method for stripping a film from a substrate, comprising:
 positioning a substrate having the film thereon in a chamber, the film comprising boron and carbon;   providing an oxygen-containing plasma in the chamber;   exposing the film to the oxygen-containing plasma to generate one or more volatile compounds from the boron and carbon;   providing a hydrogen-containing plasma in the chamber;   exposing the film to the hydrogen-containing plasma to generate one or more volatile compounds from the boron and carbon;   exhausting the oxygen-containing plasma from the chamber while continuing to provide the hydrogen-containing plasma;   exhausting the hydrogen-containing plasma from the chamber; and   exhausting at least one of the one or more volatile compounds from the chamber;   
     
     
         16 . The method of  claim 15 , wherein an atomic ratio of boron to carbon in the boron-carbon film is within a range of about 1:1 to about 3:1. 
     
     
         17 . The method of  claim 15 , wherein the substrate is disposed on a substrate support in the chamber opposite a face plate of the chamber, the oxygen-containing plasma and hydrogen-containing plasma are each maintained at a power input of at least 2,000 watts, and a spacing between the substrate and the face plate is maintained at less than 200 mils. 
     
     
         18 . The method of  claim 15 , wherein the pressure within the chamber is greater than about 5 Torr, and the substrate is positioned less than about 600 mils from a surface of a face plate located within the chamber. 
     
     
         19 . The method of  claim 15 , wherein the oxygen-containing plasma is formed from an oxygen-containing gas comprising O 2 , N 2 O, CO 2 , NO, or NO 2 , and wherein the hydrogen-containing plasma is formed from a hydrogen-containing gas comprising H 2  or NH 3 . 
     
     
         20 . The method of  claim 15 , wherein exhausting at least one of the one or more volatile compounds from the chamber is performed before and after exhausting the oxygen-containing plasma from the chamber while continuing to provide the hydrogen-containing plasma.