Abstract
We report a study on design consideration and performance analysis of OCT-based topography by tracking of maximum
intensity at each layer’s interface. We demonstrate that, for a given stabilized OCT system, a high precision and accuracy
of OCT-based layers and thickness topography in the order of tens nanometer can be achieved by using a technique of
maximum amplitude tracking. The submicron precision was obtained by over sampling through the FFT of the acquired
spectral fringes but was eventually limited by the system stability. Furthermore, we report characterization of a precision,
repeatability, and accuracy of the surfaces, sub-surfaces, and thickness topography using our optimized FD-OCT system.
We verified that for a given stability of our OCT system, precision of the detected position of signal’s peak of down to 20
nm was obtained. In addition, we quantified the degradation of the precision caused by sensitivity fall-off over depth of
FD-OCT. The measured precision is about 20 nm at about 0.1 mm depth, and degrades to about 80 nm at 1 mm depth, a
position of about 10 dB sensitivity fall-off. The measured repeatability of thickness measurements over depth was
approximately 0.04 micron. Finally, the accuracy of the system was verified by comparing with a digital micrometer
gauging.
