This paper describes the development and implementation of a TEM-based measurement procedure and shows how it is used to determine the verticality or etching angle of channel holes in V-NAND flash with more than 200 layers of memory cells. Despite the high aspect ratio of the region of interest, the method can resolve offsets down to a few nm. Such precision is critical, as the paper explains, because the radius and thus electrical characteristics of each memory cell is determined by the etching angle.

This content is only available as a PDF.
You do not currently have access to this content.