Determination of linewidth for metal/oxide gratings by measured diffraction efficiency in several orders

The algorithm for estimating the linewidth for metal oxide grating embedded in the grooves of metal grating by analyzing diffractometric measurements in transmitted and reflected light are considered. To calculate the diffraction efficiency under of rigorous electromagnetic theory, the developed algorithm uses the functions of the GD-Calc toolkit. The estimation of the linewidth from the diffraction efficiency analysis for 1μm period of the grating formed on a Ti film has demonstrated discrepancy near 5% with result obtained from analysis microimages.