Characterization of line edge roughness in resist patterns by Fourier analysis and auto-correlation function

With decreasing minimum feature: size of circuit geometry in LSIs, the effect of line edge roughness (LER) of resist patterns on the device performance is becoming a serious problem. The degree of LER, which is defined as a (standard deviation) or 3/spl sigma/ of the edge point fluctuation (/spl Delta/x/sub i/), has been measured for various resist patterns. Recently, the spatial period of the LER has also been discussed to characterize their properties. In this paper, we used two methods to evaluate the periodicity of LER, Fourier transformation, and auto-correlation function, and investigated spatial frequency characteristics of various resist materials.