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.