| 摘要 |
The present invention is an etching gas comprising an unsaturated fluorohydrocarbon represented by CxHyFz (wherein x=3, 4, or 5, y+z≦̸2x, and y>z) and a method comprising selectively etching a silicon nitride film relative to a silicon oxide film or a silicon film using the etching gas. According to the present invention, a silicon nitride film stacked on a silicon oxide film or a silicon film can be highly selectively etched. |
