Frequency domain layout decomposition in double patterning lithography

摘要

A mechanism is provided for frequency domain layout decomposition in double pattern lithography (DPL) based on Fourier coefficient optimization (FCO). The Fourier transform of a layout represents the spatial frequency terms present in the layout. The mechanism models decomposed patterns for two exposures as a function of the corresponding Fourier coefficients. For each exposure, the mechanism sets the corresponding Fourier coefficients to zero for spatial frequency terms greater than the cut-off frequency of the optical system. The mechanism then optimizes non-zero Fourier coefficients for the two exposures to decompose the original target. The mechanism provides frequency domain optimization instead of conventional spatial domain methods, which naturally leads to optics-aware decomposition and stitch insertion in arbitrary two dimensional patterns.