Method for determining low-noise power spectral density for characterizing line edge roughness in semiconductor wafer processing

摘要

According to one exemplary embodiment, a method for determining a power spectral density of an edge of at least one patterned feature situated over a semiconductor wafer includes measuring the edge of the at least one patterned feature at a number of points on the edge. The method further includes determining an autoregressive estimation of the edge of the at least one patterned feature using measured data corresponding to a number of points on the edge. The method further includes determining a power spectral density of the edge using autoregressive coefficients from the autoregressive estimation. The method further includes utilizing the power spectral density to characterize line edge roughness of the at least one patterned feature in a frequency domain.