Conformal amorphous carbon for spacer and spacer protection applications
A method of forming a nitrogen-doped amorphous carbon layer on a substrate in a processing chamber is provided. The method generally includes depositing a predetermined thickness of a sacrificial dielectric layer over a substrate, forming patterned features on the substrate by removing portions of the sacrificial dielectric layer to expose an upper surface of the substrate, depositing conformally a predetermined thickness of a nitrogen-doped amorphous carbon layer on the patterned features and the exposed upper surface of the substrate, selectively removing the nitrogen-doped amorphous carbon layer from an upper surface of the patterned features and the upper surface of the substrate using an anisotropic etching process to provide the patterned features filled within sidewall spacers formed from the nitrogen-doped amorphous carbon layer, and removing the patterned features from the substrate.
1. A method of processing a substrate in a processing chamber, comprising:
depositing a carbon-based layer on the substrate, wherein the carbon-based layer is amorphous carbon;
forming patterned features in the carbon-based layer to expose portions of the substrate;
forming a conformal spacer layer on the patterned features and exposed portions of the substrate;
forming a conformal amorphous carbon protection layer on the conformal spacer layer using a gas mixture comprising phenylacetylene, benzonitrile, acrylonitrile, pyridine, quinoline, or any combinations thereof, wherein the conformal amorphous carbon protection layer is formed at a temperature between about 25° C. to about 650° C.;
removing a portion of the conformal amorphous carbon protection layer using an anisotropic etching process to expose the conformal spacer layer on upper surfaces of the patterned features and the conformal spacer layer on the exposed portions of the substrate;
removing a portion of the conformal spacer layer using an anisotropic etching process to expose the upper surfaces of the patterned features and the exposed portions of the substrate;
after removing a portion of the conformal spacer layer, removing the conformal amorphous carbon protection layer from the substrate;
removing the carbon-based layer from the substrate; and
exposing the substrate to an etching chemistry using the remaining portions of the conformal spacer layer as a hardmask to remove at least exposed portions of the substrate.
2. The method of claim 1 , wherein the gas mixture further comprises a dilution gas comprising helium, hydrogen, nitrogen, ammonia, or any combinations thereof.
3. The method of claim 1 , wherein the conformal amorphous carbon protection layer is formed at a temperature between about 200° C. to about 400° C. and a chamber pressure of about 5 Torr to about 15 Torr.
4. The method of claim 1 , wherein the substrate comprises a plurality of alternating oxide and nitride materials.
5. The method of claim 1 , wherein the substrate comprises oxides alternating with amorphous silicon or polysilicon.
6. A method of processing a substrate in a processing chamber, comprising:
depositing a carbon-based layer on the substrate, wherein the carbon-based layer is hydrogenated amorphous carbon;
forming patterned features in the carbon-based layer to expose portions of the substrate;
forming a conformal spacer layer on the patterned features and exposed portions of the substrate;
forming a conformal amorphous carbon protection layer on the conformal spacer layer using a gas mixture comprising phenylacetylene, benzonitrile, acrylonitrile, pyridine, quinoline, or any combinations thereof, wherein the conformal amorphous carbon protection layer is formed at a temperature between about 25° C. to about 650° C.;
removing a portion of the conformal amorphous carbon protection layer using an anisotropic etching process to expose the conformal spacer layer on upper surfaces of the patterned features and the conformal spacer layer on the exposed portions of the substrate;
removing a portion of the conformal spacer layer using an anisotropic etching process to expose the upper surfaces of the patterned features and the exposed portions of the substrate;
after removing a portion of the conformal spacer layer, removing the conformal amorphous carbon protection layer from the substrate;
removing the carbon-based layer from the substrate; and
exposing the substrate to an etching chemistry using the remaining portions of the conformal spacer layer as a hardmask to remove at least exposed portions of the substrate.
7. The method of claim 6 , wherein the gas mixture further comprises a dilution gas comprising helium, hydrogen, nitrogen, ammonia, or any combinations thereof.
8. The method of claim 6 , wherein the conformal amorphous carbon protection layer is formed at a temperature between about 200° C. to about 400° C. and a chamber pressure of about 5 Torr to about 15 Torr.
9. The method of claim 6 , wherein the substrate comprises a plurality of alternating oxide and nitride materials.
10. The method of claim 6 , wherein the substrate comprises oxides alternating with amorphous silicon or polysilicon.