A new method for non-destructive measuring of grating parameters

At present, scanning electron microscopy (SEM) and atomic force microscopy (AFM) are the main means of measuring grating parameters. When SEM is used, irreversible damage will be caused to the sample. AFM can only detect small areas of samples. AFM is too inefficient for large area diffraction gratings. Therefore, non-destructive testing of grating groove shapes is very necessary. In this paper, the light intensity 、diffraction angle of first-order and diffracted light interferometric fringes are studied and a new method for non-destructive measuring of grating parameter is proposed. We will study the grating parameters based on the rigorous coupled wave theory (RCWA).