摘要 |
A processing method is provided for plasma etching features in a silicon nitride (SiN) film covered by a mask pattern. The method includes providing a film stack on a substrate, the film stack containing a SiN film on the substrate and a mask pattern on the SiN film, transferring the mask pattern to the SiN film by exposing the film stack to a first plasma containing a carbon-fluorine-containing gas, O2 gas, and optionally HBr gas, and exposing the film stack to a second plasma containing a carbon-fluorine-containing gas, O2 gas, a silicon-fluorine-containing gas, and optionally HBr gas. |