Hard mask and method for manufacturing same

In one embodiment, this hard mask for plasma etching is formed on a silicon-containing film. The hard mask is an amorphous film, and includes tungsten and silicon. The ratio of the concentration of tungsten and the concentration of silicon in the surface of the hard mask can be within the range between a ratio stipulating that the concentration of tungsten is 35 at% and the concentration of silicon is 65 at% and a ratio stipulating that the concentration of tungsten is 50 at% and the concentration of silicon is 50 at%.