| 摘要 |
PROBLEM TO BE SOLVED: To secure the shape of the gate electrode at the time of etching the gate electrode of polymetal structure and to improve the etching selection ratio with respect to an etching stopper film constituted of silicon nitride. SOLUTION: When W films 8, WNX films 7 and polycrystalline silicon films 6 of gate electrode materials, are dry-etched by using silicon nitride films 9 as the masks, mix gas formed of SF6 , oxygen and nitrogen is used as the plasma source gas. |
