Patent ID: 8891080

Claim:
A method for detecting levels of surface contamination of substrates used in imprint lithography, the method comprising the steps of: providing a substrate; depositing polymerizable material in a periodic drop pattern on the substrate; contacting the polymerizable material with a blank imprint template; polymerizing the polymerizable material to form an imprint layer on the substrate; detecting the presence of defects on the imprint layer; analyzing the detected defects and identifying periodic nanovoid defects within the detected defects; and determining the number of periodic nanovoid defects per unit area of substrate, wherein the number of periodic nanovoid defects per unit area correlates to the level of surface contamination of the substrate; wherein the detecting step further comprises using light scattering techniques, and further comprising the step of generating a scatter map of the substrate, and wherein the analyzing step further comprises performing a Fourier transform (FFT) analysis of the scatter map.