Method for inspecting photomask blank or intermediate thereof, method for determining dosage of high-energy radiation, and method for manufacturing photomask blank

A method for inspecting a photomask blank or an intermediate thereof which is manufactured by depositing a phase shift film on a photomask-forming substrate and irradiating the phase shift film with high-energy radiation to effect substrate shape adjusting treatment, the method comprising the steps of:

• measuring a surface topography of the photomask blank or intermediate after the substrate shape adjusting treatment,
• removing the phase shift film from the photomask blank or intermediate,
• measuring a surface topography of the treated substrate after removal of the phase shift film, and
• comparing the surface topography of the photomask blank or intermediate with the surface topography of the treated substrate, thereby evaluating a warpage change before and after removal of the phase shift film, due to a stress of the phase shift film having undergone substrate shape adjusting treatment.