Generic E-Beam Compensatory Carbon Deposition Method for High Aspect Ratio (HAR) TEM Sample Preparation

A focused ion beam (FIB) based TEM lamella preparation technique specifically designed for high aspect ratio (HAR) samples, using generic E-beam compensatory carbon deposition method is demonstrated in this paper. It provides a comprehensive and reproducible implementation process with clear schematic workflow. The ultra-thin HAR lamella, 30 nm final thickness, prepared using this technique achieve precise endpoint, uniform thickness, and remain free from bending or damage, regardless of whether the etch holes are filled. Subsequent TEM analysis shows clear profiles in the region of interest with less curtaining effect and redeposition contamination.