| abstract |
A method for opening an amorphous carbon layer mask underlying a hard mask is provided. Opening the amorphous carbon layer mask includes performing one or more cycles, wherein each cycle includes an opening phase and a cleaning phase of the amorphous carbon layer mask. The opening phase of the amorphous carbon layer mask includes: flowing an opening gas into the plasma processing chamber, wherein the opening gas includes an oxygen-containing component; and generating a plasma from the opening gas, the plasma in the non-crystalline etching features in the crystalline carbon layer mask; and stopping the flow of the opening gas. The cleaning stage includes: flowing a cleaning gas into the plasma processing chamber, wherein the cleaning gas includes a hydrogen-containing component, a carbon-containing component, and a halogen-containing component; generating a plasma from the cleaning gas; and stopping all The cleaning gas flows into the plasma processing chamber. |