Abstract
A theoretical analysis to estimate the effect of shot noise on CDU is induced from optical imaging perspectives combined with quantum theory, and is studied for 193-nm, EUV, and electron beam lithography. We found the CDU variation from shot noise is related to the number of particles absorbed in the printed area and to the image log slope (ILS). Hence, the CDU variation contributed by shot noise gets worse when the technology node advances from 45- to 32-, 22-, and 15-nm, EUV with higher ILS is no exception. For e-beam lithography, we are interested in the values of ILS calculated from array structures with different pitches, backscattering, wafer-stage movement, and raster-scan writing.