Wide-field massive CD metrology based on the imaging Mueller-matrix ellipsometry for semiconductor devices

In this paper, we propose an unique metrology technique for the measurement of three-dimensional (3D) nanoscale structures of semiconductor devices, employing imaging-based massive Mueller-matrix spectroscopic ellipsometry (MMSE) with ultra-wide field of view (FOV) of 20×20 mm². The proposed system enables rapid measurement of 10 million critical dimension (CD) values from all pixels in the image, while the conventional point-based metrology technique only measures a single CD value. We obtain Mueller matrix (MM) spectrum by manipulating wavelength and polarization states using a custom designed optical setup, and show that the proposed method characterizes complex 3D structures of the semiconductor device. We experimentally demonstrate CD measurement performance and consistency in the extremely large FOV, and suggest that the combination of MMSE and massive measurement capability can provide valuable insights: fingerprints originated from the manufacturing process, which are not easily obtained with conventional techniques.