Micro-structure characterization based on white light interferometry

Abstract

White light interferometry(WLI) has grown to be a standard measurement method in the field of micro/nano manufacture. Vertical white light scanning interferometry(VSI), tilt white light scanning interferometry(TSI) and white light phase shifting interferometry(WLPSI) are introduced in this paper. A new algorithm based on the combination of VSI and image segmentation technology for measuring the film is presented in this paper. TSI is taken place of VSI for expanding its lateral measuring range and improving the testing efficiency as the vertical and lateral information of the samples are obtained after one time scan. Carre phase shifting is combined with vertical white light scanning which formed a white light phase shifting method. The measurement system equips a Mirau microscopic interferometer, and the scanning process is driven by nano-measuring machine(NNM) which is a high precision nano-positioner. At last, the testing results of some micro-structures illustrate the capabilities of the proposed algorithms.