In-Situ Carbon Deposition in FIB for Reducing TEM Lamella Curtains Caused by Air Gaps in NAND Flash Memory

An in situ air gaps fill-in approach was investigated by conducting a convenient way in dual-beam FIB. We employed a well-controlled deposition to precisely fill carbon into air gaps. It greatly reduced formation of the artifacts and avoided the profiles of air gaps by reducing striations and damages during FIB milling. Generally, the effect of air gaps between wordlines or between metal lines, as well as some unexpected defect voids can be eliminated in most cases if this ideal method is applied.