Abstract-Steep large film thickness measurement with off-axis terahertz digital holography reconstructed by a direct Fourier and Hermite polynomial

Dahi Ghareab Abdelsalam Ibrahim

https://www.osapublishing.org/ao/abstract.cfm?uri=ao-57-10-2533

In this paper, we enhance the steepness of film thickness edge in terahertz off-axis digital holography by employing a reconstruction method based on a direct Fourier and Hermite polynomial function. The method is applied to samples of 110 μm and 80 μm step heights to extract the phase images in real time. Use of this method reduces the resolution factor by around one half, representing around a 50% decrease in critical dimension as compared with conventional measurements. The method is very promising and opens the route to potential applications in the fields of microlithography.

© 2018 Optical Society of America