Phase shift mask blank, phase shift mask, and pattern transfer method

A phase shift mask blank comprising a phase shift multilayer film on a substrate,

• said phase shift multilayer film consisting of
• at least one layer of light absorption function film formed of a metal, a metal and silicon, or an unsaturated metal compound in the form of an oxide, nitride, carbide, oxynitride, oxynitride carbide or nitride carbide comprising a metal or a metal and silicon as primary elements, and
• at least one layer of phase shift function film formed of an oxide, nitride, carbide, oxynitride, oxynitride carbide or nitride carbide comprising a metal or a metal and silicon,
• said light absorption function film having an extinction coefficient k relative to light of wavelength 157 to 260 nm which increases from the wavelength 157 nm toward 260 nm, and said light absorption function film having a thickness of up to 15 nm.