| abstract |
Etching of carbonaceous layers with an etchant gas mixture including molecular oxygen (O 2 ) and a gas including a carbon sulfur terminal ligand. A high RF frequency source is employed in certain embodiments to achieve a high etch rate with high selectivity to inorganic dielectric layers. In certain embodiments, the etchant gas mixture includes only the two components, COS and O 2 , but in other embodiments additional gases, such as at least one of molecular nitrogen (N 2 ), carbon monoxide (CO) or carbon dioxide (CO 2 ) may be further employed to etch to carbonaceous layers. |