| abstract |
This invention aims to realize, upon forming highly detailed masks, all aspects inclusive of improving the selection ratio of the mask, controlling the LWR and LER, and reducing the influence due to the uneven density of the patterns. In one embodiment, a wafer includes an etched layer EL, an organic film OL, an antireflection film AL and a mask MK1. A method MT according one embodiment comprises a step of conducting an etching treatment with respect to the antireflection film AL in a processing container 12 of a plasma processing device 10 in which the wafer is received, with the mask MK1, by means of plasma generated in a processing container 12. The step comprises steps ST3a～ST4 of conformally forming a protection film SX on the surface of the mask MK1, and ST6a～ST7 of etching the antireflection film AL by removing the antireflection film AL, atomic layer by atomic layer, using the mask MK1 formed with the protection film SX. |