We propose a novel spectrum measurement system named Microsphere-assisted nanospot spectroscopic reflectometry (MASR) by using the super-resolution image over the Rayleigh’s resolution limit in white-light. The proof of concept and optimal configuration of MASR are fully verified by utilizing both FDTD and ray optics simulations. At the same time, we experimentally validate the usefulness of MASR by obtaining the spectra from extremely small spot of 210 nm which is 119X smaller than 25 μm of conventional spectrum measurement system due to 530X super resolution enhanced magnification by optimally using microsphere that is definitely overcoming the physical limit of the optical resolution. It is important to note that the proposed technique has a capability to measure the spectrum from the extremely tight area, diameter of 210 nm, resulting in monitoring in-cell uniformity and structural changes in narrow and small area device patterns. Furthermore, our system can be combined with various optical measurement systems as a module which can upgrade optical resolution and magnification. To the best of our knowledge, this is the world first demonstration of completely new concept of the system and the method to overcome the metrology challenges we are currently facing.
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