Ultra-conformal carbon film deposition
Embodiments of the disclosure relate to deposition of a conformal carbon-based material. In one embodiment, the method comprises depositing 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, introducing a hydrocarbon source, a plasma-initiating gas, and a dilution gas into the processing chamber, generating a plasma in the processing chamber at a deposition temperature of about 80° C. to about 550° C. to deposit a conformal amorphous carbon layer on the patterned features and the exposed upper surface of the substrate, selectively removing the 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, and removing the patterned features formed from the sacrificial dielectric layer.
1. A method of forming a conformal amorphous carbon layer on a substrate in a processing chamber, comprising:
depositing a dielectric layer on a substrate;
depositing a sacrificial dielectric layer on an upper surface of the dielectric layer;
forming a pattern into the sacrificial dielectric layer by removing portions of the sacrificial dielectric layer to expose portions of the upper surface of the dielectric layer;
introducing a hydrocarbon source, a plasma-initiating gas, and a dilution gas into the processing chamber, wherein a volumetric flow rate of hydrocarbon source:plasma-initiating gas:dilution gas is in a ratio of 1:0.5:20;
generating a plasma in the processing chamber to deposit a conformal amorphous carbon layer on the portions of the upper surface of the dielectric layer and on remaining portions of the sacrificial dielectric layer;
selectively removing the amorphous carbon layer using an anisotropic etching process to expose upper surfaces of the remaining portions of the sacrificial dielectric layer and to expose the upper surface of the dielectric layer; and
removing the remaining portions of the sacrificial dielectric layer.
2. The method of claim 1 , further comprising:
introducing a nitrogen-containing gas into the processing chamber.
3. The method of claim 2 , wherein the nitrogen-containing gas is introduced at a nitrogen-containing gas to a hydrocarbon source ratio of about 1:40 to about 10:1.
4. The method of claim 1 , wherein the plasma is generated in the processing chamber at a deposition temperature of about 200° C. or less.
5. The method of claim 1 , wherein the hydrocarbon compound comprises acetylene (C 2 H 2 ), ethylene (C 2 H 4 ), ethane (C 2 H 6 ), propylene (C 3 H 6 ), propyne (C 3 H 4 ), propane (C 3 H 8 ), butane (C 4 H 10 ), butylene (C 4 H 8 ), butyne (C 4 H 6 ), phenylacetylene (C 8 H 6 ), or combinations thereof.
6. The method of claim 1 , wherein the hydrocarbon source is a nitrogen-containing hydrocarbon source.
7. The method of claim 6 , wherein the nitrogen-containing hydrocarbon source is described by the formula CxHyNz, where x has a range of between 1 and 12, y has a range of between 2 and 20, and z has a range of between 1 and 10.
8. The method of claim 7 , wherein the nitrogen-containing hydrocarbon source comprises one or more nitrogen containing hydrocarbon compounds selected from the group consisting of methylamine, dimethylamine, trimethylamine (TMA), triethylamine, aniline, quinoline, pyridine, acrylonitrile, benzonitrile, and combinations thereof.
9. The method of claim 1 , wherein the amorphous carbon layer is a nitrogen-doped amorphous carbon having a carbon:nitrogen ratio of between about 0.1% nitrogen to about 10% nitrogen.