A Method for Directly Correlating Site-Specific Cross-Sectional and Plan-View Transmission Electron Microscopy of Individual Nanostructures

Abstract

A sample preparation method is described for enabling direct correlation of site-specific plan-view and cross-sectional transmission electron microscopy (TEM) analysis of individual nanostructures by employing a dual-beam focused-ion beam (FIB) microscope. This technique is demonstrated using Si nanowires dispersed on a TEM sample support (lacey carbon or Si-nitride). Individual nanowires are first imaged in the plan-view orientation to identify a region of interest; in this case, impurity atoms distributed at crystalline defects that require further investigation in the cross-sectional orientation. Subsequently, the region of interest is capped with a series of ex situ and in situ deposited layers to protect the nanowire and facilitate site-specific lift-out and cross-sectioning using a dual-beam FIB microscope. The lift-out specimen is thinned to electron transparency with site-specific positioning to within ≈ 200 nm of a target position along the length of the nanowire. Using the described technique, it is possible to produce correlated plan-view and cross-sectional view lattice-resolved TEM images that enable a quasi-3D analysis of crystalline defect structures in a specific nanowire. While the current study is focused on nanowires, the procedure described herein is general for any electron-transparent sample and is broadly applicable for many nanostructures, such as nanowires, nanoparticles, patterned thin films, and devices.

An Atomistic Tomographic Study of Oxygen and Hydrogen Atoms and their Molecules in CVD Grown Graphene

“…The position of the APT sample utilized was close to the edge of the monolayer graphene to avoid the multilayer regions. Precise positioning of the graphene layer on the nanometer‐scale nanotip was achieved using correlative SEM, TEM, and APT experiments, which were executed utilizing a dual‐beam focused ion‐beam (FIB) microscope to lift‐out a graphene specimen and attach it to a Omniprobe TEM Cu grid (Supporting Information, Section S2).…”

FIB Plan and Side View Cross-Sectional TEM Sample Preparation of Nanostructures

“…A method for both side view (after detachment from substrate) and plan view (after FIB processing) TEM imaging of specific nanowires has previously been proposed by Schreiber et al (2012). This method makes it possible to select a cross-section that includes sparsely formed features in the nanowires, such as quantum dots (Heiss et al, 2013).…”

“…For nanowires these issues have prevented FIB from being used for TEM sample preparation to any greater extent, despite the significant advantages this method could offer. Recently, methods have been reported that overcome some of the issues regarding ion beam damage (Dieker et al, 2012; Fauske et al, 2012; Schreiber et al, 2012; Vieweg et al, 2012). However, these methods are applied to very few nanowires at a time which makes them impractical if a large number of nanowires are to be investigated in order to, for example, gain statistical information.…”

Two‐In‐one sample preparation for plan‐VIew TEM

“…Most artefacts may appear also in case of conventional Ar + ‐ion milling, however, because of lower accelerating voltage and atomic mass of Ar, in a lesser extent. The FIB‐cutting of plan‐view samples is not straightforward (Floresca et al, ; Jublot and Texier, ; Schreiber, ) In addition, the TEM‐transparent area obtained by FIB is typically smaller than that by conventional fabrication.…”