Method for detecting stochastic weak points of layout pattern of semiconductor integrated circuit and computer system performing the same

A method for detecting a stochastic weak point of a layout pattern of a semiconductor integrated circuit includes: forming a semiconductor integrated circuit by exposing a wafer which is masked by a layout pattern and coated with a photoresist to light, and etching the circuit according to the layout pattern, calculating line edge roughness (LER) of the circuit, and calculating a variability constant for fitting the line edge roughness to a normal distribution from a polymer concentration value of the photoresist. The polymer concentration value is calculated from modeling the layout pattern, a total value of intensity of light reaching the photoresist, and an intensity value of light reaching one point of the photoresist. The method further includes calculating a probability distribution of the polymer concentration value of the layout pattern based on the variability constant, and calculating a stochastic weak point of the layout pattern from the probability distribution.