Patent ID: 8048589
Filing Date: 2011-11-01
Classification: G03F

Abstract:
1. A method for inspecting a phase shift photomask to qualify or disqualify said photomask from use in a photolithography process comprising: providing a phase shift photomask having an active pattern region; measuring within the active pattern region an optical property of the phase shift photomask including measuring a transmittance value of radiation transmitted through a patterned ordered array comprising said active pattern region while excluding from said measuring an immediately adjacent incompletely opaque non-active pattern border region of the phase shift photomask to qualify or disqualify said photomask for use in a photolithography process; said ordered array comprises an array of a minimum dimension of 3×3 transparent regions defined within said incompletely opaque material layer; and, disqualifying said photomask from use in said photolithography process if said optical property is not within an acceptable range, said acceptable range having the effect of avoiding transmitted radiation sidelobes through said phase shift mask in a photoexposure process comprising said photolithography process.