Overview of the Dual-Beam FIB/SEM System

Machining at the Nanoscale: Applications of the Focused Ion Beam (FIB)/Scanning Electron Microscope (SEM) System

Paul Blanchard, Kris Bertness, Ann Chiaramonti Debay, Alexana Roshko, Aric Sanders, Norman Sanford, and Joel Weber 

National Institute of Standards and Technology (NIST), Boulder, CO

Introduction

Sample Preparation I: the Transmission Electron Microscopy (TEM) Lamella

Goal: from an arbitrary specimen of interest, create an ultra-thin (< 100 nm thick) cross-sectional slice (a lamella) suitable for TEM imaging

Step 2 – Cut out the cross section and use the 

micromanipulator to extract it from the substrate

Step 1 – Protect sample by capping with Pt, then 

create a cross sectional slice (lamella) by FIB milling

Step 3 – Attach the lamella to a 

TEM sample mount

Step 4 – Progressively thin lamella to 

electron transparency (< 100 nm thickness) 

Specimen: GaN/InGaN Nanowire 

(NW) LED Device on Si Substrate

NW 

encased 

in FIBID 

Pt cap

Si Substrate

Lamella

TEM sample 

mount

Micromanipulator tip

Lamella

FEBID Pt bond

TEM image of GaN/InGaN NW

Possible stacking 

faults

High In-fraction 

inclusion

Finished GaN/InGaN NW Lamella

Pt cap

GaN/InGaN NW 

cross section

Si Substrate

Sample Preparation II: the Atom Probe Tomography (APT) Tip

Goal: from an arbitrary specimen of interest, remove a sample of material and shape it into an

ultra-sharp (< 50 nm diameter at tip apex) needle suitable for APT

Specimen: HSLA80 Steel 

Step 1 – Cap with Pt, then FIB mill a 

cantilever with a triangular cross section

Step 2 – Cut cantilever free and extract 

from substrate via micromanipulator

Step 3– Attach a ~2 μm section of the cantilever to a Si 

post and cut free. Repeat to create a set of 10 APT tips.

Step 4 – Use annular milling (milling 

in ring shapes of decreasing size) to 

create final needle shape for APT.

Transmission electron microscopy (TEM) and atom probe tomography

(APT) are powerful imaging techniques that allow quantitative material

analysis on the scale of individual atoms.

However, each of these techniques places stringent constraints on the

geometry of specimens that can be analyzed. Sample cross sections for

TEM must be thinned to electron transparency (< 100 nm thickness); APT 

requires a needle-shaped tip with a diameter on the order of 50 nm or less

at its apex.

The dual-beam focused ion beam (FIB)/scanning electron microscope

(SEM) system enables the machining and manipulation of samples with

nanometer-scale control. As a result, high-quality samples for TEM and

APT can be fabricated from a wide variety of material systems. In addition,

dual-beam techniques can be adapted to the fabrication of novel test

structures and prototype devices.

2 μm

2 μm 10 μm 10 μm 10 μm

10 μm

1 μm 1 μm 2 μm

5 μm

2 μm

5 μm 2 μm

10 μm

2 μm

2 μm 2 μm 2 μm

2 μm

5 μm

5 μm 5 μm 5 μm

5 μm

5 μm 2 μm 2 μm

5 μm

10 μm 2 μm 2 μm 2 μm

1 μm

1 μm

1 μm 1 μm

100 nm

3D Atom Probe Reconstruction of Steel Tip

Carbide 

inclusions

Possible 

solute 

segregation 

at carbide 

interfaces

Finished Steel APT Tip

Pt cap

Bottom 

edge of 

cantilever

FEBID Pt coating on NW NW encased in FIBID Pt Trench milled from side 1

Prototype Device Example: the Nanowire (NW) Scanning Probe Tip The dual-beam system combines the high-resolution, low-damage

imaging of SEM with the precise milling capabilities of FIB. With the

addition of a gas injector (for beam-induced deposition) and a

micromanipulator, the system allows samples to be imaged, milled, cut,

moved, and welded to new substrates.

Trench milled from side 2

Lamella cut out from 

surrounding Si

Manipulator brought in Manipulator Pt-welded 

to lamella

Lamella cut free

TEM mount prepared

Lamella brought in

Manipulator cut free

Lamella Pt-welded to post Lamella thinned by FIB

FIBID Pt cap deposited Angled mill from side 1 Angled mill from side 2

Manipulator Pt-welded Manipulator brought in

to cantilever

Cantilever cut free

Micromanipulator tip

FEBID Pt weld Cantilever

Si mounting post 

prepared

Cantilever brought in End section of cantilever 

Pt-welded to Si post

Remaining cantilever cut 

free

Pt cap

Si post

Pt welds

Steel

20 nm tip 

diameter

In addition to the preparation of samples for TEM and APT, the dual-beam system can be

used to fabricate prototype nanoscale device structures, such as the GaN nanowire (NW)

near-field scanning microwave microscopy (NSMM) probe. 

Pluck NW from growth substrate and 

mount it to FIB-prepared AFM tip

Si cantilever

AFM tip

FIB-milled 

hole

GaN NW

FEBID Pt 

weld

Color shows change in amplitude of |S11| microwave reflection parameter (relative to calibrated 

minimum |S11| ≡ −45 dBm) 

Performance of GaN NW NSMM Probe Tip Fabricated in the Dual-Beam FIB/SEM System

Weber et al., Appl. Phys. Lett. 104, 023113 (2014) 

Schematic of Test Measurement Setup Commercial Pt probe tip (not a nanowire)

NW tip coated by ~3 nm Al2O3/25 nm W via 

atomic layer deposition (ALD)

Other applications

Polished surface of steel specimen

The dual-beam FIB/SEM is a versatile system that continues to be adapted to new

applications , such as

• 3D tomography. By taking a series of successive SEM images while FIB milling through a

region of interest, a 3D reconstruction of the material volume can be obtained.

• In situ electrical and mechanical testing. With the tungsten probe micromanipulator

operating as an electrical or mechanical probe, materials and devices can be

characterized in situ with high spatial resolution and simultaneous SEM observation.

• Custom nano-milling. Because the FIB position and dwell time can be precisely

controlled, arbitrary nanoscale shapes can milled into substrates, and existing

nanostructures can be reshaped.

Lamella thinned by FIB Lamella thinned by FIB

FIB annular mill

FIB annular mill FIB annular mill