Continuum model of shot noise and line edge roughness

Decreasing feature size implies increased sensitivity to statistical fluctuations which impact critical dimension (CD) uniformity and control. In a recent work Gallatin and Liddle presented equations which describe the basic processes leading to surface and line edge roughness (LER) in a chemically amplified resist. Retaining only the lowest order terms in what is inherently, a very nonlinear problem they were able to derive a scaling law and other dependencies which show reasonable agreement with experimental data. Here the analysis of the same equations is extended and expanded to include the dominant nonlinear effects.