A New Metrology Technique for Defect Inspection Via Coherent Fourier Scatterometry Using Orbital Angular Momentum Beams

Coherent Fourier scatterometry (CFS) using laser beams with a Gaussian spatial profile is routinely used as an in-line inspection tool in semiconductor industry. Here, a set of novel defect inspection techniques are proposed and investigated numerically, which are based on bright-field CFS using coherent beams that carry orbital angular momentum (OAM). Through numerical simulations, we demonstrated that it shows up to an order of magnitude higher in signal-to-noise ratio over the conventional Gaussian beam CFS.