| abstract |
An object of the present invention is to etch a tungsten film with high uniformity in the in-plane direction of the wafer, in the depth direction of the pattern, and high dimensional controllability of the atomic layer level. In order to solve such a problem, in a method of etching a tungsten film, a fluorine-containing reaction species produced in the plasma in a state in which a substrate having a tungsten film formed on at least a part of its surface is cooled to a temperature equal to or lower than the melting point of tungsten fluoride, To form a surface reaction layer on a tungsten film formed on the surface of the substrate; and a second step of forming a substrate having the surface reaction layer on the tungsten film at a temperature higher than the boiling point of the tungsten fluoride by a second predetermined And a second step of removing the surface reaction layer formed on the tungsten film by heating for a predetermined period of time. |