Molecular roughness analysis of developed resist by LER method

In this paper, line edge roughness (LER) analysis on top–down images acquired by means of a scanning electron microscope is here proposed as a powerful and non-invasive technique to map the molecular aggregate distribution in a chemically amplified resist: in particular the periodicity of the aggregates themselves is determined via power spectral density method (PSD). The roughness of two resist developers with different chemical composition will be compared on the base of 1D power spectral density function: in case of SEM acquisition, the profile to be analyzed is extracted from a top–down acquisition, while atomic force microscope (AFM) inspection of surface topography allows to calculate PSD along a user-defined line. The two approaches confirm a reduced surface roughness in case of development with smaller molecule.