Feasibility and challenge for measurement of transparent object by adopting differential interference contrast technology

Abstract

The Differential Interference Contrast approach (DIC) which is frequently used for image enhancement to increase the contrast between transparent object and its background is adopted for the dimensional measurement of a transparent structure. With the phase difference image retrieved using the DIC technique, the phase map of the examined object can be approximated by integrating the phase difference. Experimental results show the feasibility of using the transmitted DIC for transparent object measurement. The results show that the height of a transparent structure measured using the DIC method is quite close to those measured using AFM while those measured using the white light interference method results in much larger measurement than all others. However, when a structure is no longer a simple geometry, adopting this method directly might results in wrong results. In this paper, we would like to present the work had been done, discuss the challenge ahead, and possible approach can be adopted..