Patent ID: 7354684

Claim:
A method for evaluating the transfer properties of a test pattern, which comprises: providing a photomask with a test pattern having: lines having a line width and two lateral sides extending along a reference direction; and periodic structures directly adjacent and connected with the lines; transferring the test pattern to, thereby, obtain an image of the test pattern; determining edges of the image of the test pattern and obtaining therefrom a set of edge position data; fitting the edge position data to a straight line and determining edge position residuals; calculating an amplitude spectrum dependent upon spatial frequencies to, thereby obtain a relationship A(f,image) representing the amplitude in dependence of the spatial frequency; determining a maximum A(fx,image) of the relationship A(f,image); determining a maximum A(fx,photomask) of a reference amplitude spectrum; and forming a ratio of the maximum A(fx,image) of the image of the test pattern and the maximum A(fx,photomask).