Methods of dry stripping boron-carbon films
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 boron-carbon film from a substrate, comprising:
positioning the substrate having the boron-carbon film thereon in a chamber;
exposing the boron-carbon film to a plasma containing oxygen radicals or ions and hydrogen radicals or ions;
reacting the hydrogen radicals or ions with the boron to form a volatile boron species;
reacting the oxygen radicals or ions with the carbon to form a volatile carbon species; and
exhausting the volatile boron species and the volatile carbon species from the chamber, wherein the exposing the boron-carbon film comprises:
introducing a processing gas comprising H x O y to the chamber, wherein x and y are integers or non-integers greater than 1; and
generating a plasma from the processing gas.
2. The method of claim 1 , wherein the processing gas comprising H x O y comprises water vapor.
3. The method of claim 2 , wherein the exposing the boron-carbon film comprises:
generating water vapor using a water vapor generator;
flowing the water vapor into the chamber; and
forming a plasma from the water vapor using RF power.
4. The method of claim 1 , wherein a 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.
5. A method for stripping a boron-carbon film from a substrate, comprising:
positioning the substrate having the boron-carbon film thereon in a chamber;
exposing the boron-carbon film to a plasma containing oxygen radicals or ions and hydrogen radicals or ions;
reacting the hydrogen radicals or ions with the boron to form a volatile boron species;
reacting the oxygen radicals or ions with the carbon to form a volatile carbon species; and
exhausting the volatile boron species and the volatile carbon species from the chamber, wherein the exposing the boron-carbon film comprises:
introducing a processing gas comprising H x O y and at least one of an oxygen-containing compound, or a hydrogen containing compound to the chamber, wherein x and y are integers or non-integers greater than 1; and
generating a plasma from the processing gas.
6. A method for stripping a film comprising boron and carbon from a substrate, comprising:
positioning the substrate having the film thereon in a chamber;
exposing the film to a plasma comprising oxygen ions or radicals and hydrogen ions or radicals, wherein the plasma is formed from a compound comprising H x O y , where x and y are integers or non-integers greater than 1;
reacting the hydrogen radicals or ions with the boron to form a volatile boron species and reacting the oxygen radicals or ions with the carbon to form a volatile carbon species by contacting the film with the plasma; and
exhausting the volatile boron species and the volatile carbon species from the chamber.
7. The method of claim 6 , wherein a 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.
8. The method of claim 6 , wherein the substrate is maintained at a temperature within a range of about 200° C. to about 400° C.