Plasma etching carbonaceous layers with sulfur-based etchants
AssigneeApplied Materials, Inc.
InventorsJudy Wang, Shawming Ma, Chang-Lin Hsieh, Bryan Liao, Jie Zhou, Hun Sang Kim
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Abstract
Etching of carbonaceous layers with an etchant gas mixture including molecular oxygen (O2) 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 O2, but in other embodiments additional gases, such as at least one of molecular nitrogen (N2), carbon monoxide (CO) or carbon dioxide (CO2) may be further employed to etch to carbonaceous layers.
Claims18
A method of etching a feature in a carbonaceous layer comprising
- at least 20 wt % carbon, the method comprising:
- providing a substrate including the carbonaceous layer;
- loading the substrate into a plasma etch chamber;
- introducing an etchant gas mixture including O2 and a gas comprising a carbon sulfur terminal ligand into the plasma etch chamber;
- etching the carbonaceous layer with a plasma of the etchant gas mixture energized with a high frequency RF source having a RF frequency above 100 MHz.
A method of etching an amorphous carbon layer comprising at least 50 wt % carbon, comprising:
- providing a substrate including a multi-layered mask on a substrate layer, the multi-layered mask comprising:
- the amorphous carbon layer disposed on the substrate layer;
- an inorganic dielectric cap layer disposed on the amorphous carbon layer;
- and a patterned photoresist layer disposed over the inorganic dielectric cap layer;
- loading the substrate into a plasma etch chamber;
- introducing an etchant gas mixture including O2 and a gas comprising a carbon sulfur terminal ligand into the plasma etch chamber;
- etching the amorphous carbon layer with a plasma of the etchant gas mixture.
Dependencies are inferred from the claim text.