The modified weighted gauss-fitting algorithm for structured-illumination microscopy

Structured-illumination microscopy (SIM) is a novel instrument for measuring surface topography. After images captured by SIM, optical-sectioned images can be acquired by sectioned by section algorithm. Finally, the peak point can be obtained by gauss fitting algorithm based on sectioned images. However, classical gauss-fitting is an inaccurate method since it is sensitive to noise. In this paper, the modified weighted-gauss fitting algorithm (MWGFA) is applied to peak extract. Through simulation and wafer measurement experiment, MWGFA is demonstrated to be an effective method to fitting the SIM z-axis response curve obviously. Compared with CM, MWGFA behaves better in accuracy. Thus it is suitable for SIM well enough and improve the measurement accuracy in mirror and wafer with steps.