Patent ID: 8331647

Claim:
A method of determining a defect size of an evaluation pattern used to evaluate defect detection sensitivity, which measures a dimension of a reference pattern and the corresponding dimension of said evaluation pattern and calculates the difference between the measured value of said dimension of said reference pattern and the measured value of said dimension of said evaluation pattern to determine said defect size of said evaluation pattern, wherein said reference pattern and said evaluation pattern are formed on an evaluation mask used to evaluate the defect detection sensitivity of a mask defect inspection system, and wherein the design value of said dimension of said evaluation pattern differs from the design value of said dimension of said reference pattern by a predetermined amount, said method comprising: measuring said dimension of said reference pattern, said dimension of said evaluation pattern, the corresponding dimension of a first adjacent pattern, and the corresponding dimension of a second adjacent pattern, wherein said first adjacent pattern is formed adjacent to and in a predetermined positional relationship with said reference pattern, wherein said second adjacent pattern is formed adjacent said evaluation pattern so that said second adjacent pattern is in the same positional relationship with respect to said evaluation pattern as is said first adjacent pattern with respect to said reference pattern, and wherein the design value of said dimension of said second adjacent pattern is the same as that of said dimension of said first adjacent pattern; calculating the ratio of the measured value of said dimension of said first adjacent pattern to the measured value of said dimension of said second adjacent pattern; and multiplying the measured value of said dimension of said evaluation pattern by said ratio and calculating the difference between the resulting value and the measured value of said dimension of said reference pattern to determine said defect size of said evaluation pattern.