[PPT] - QUANTIFIABLE COMPARATIVE EVALUATION OF FIB/SEM INSTRUMENTS Valery PowerPoint Presentation

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

QUANTIFIABLE COMPARATIVE EVALUATION OF FIB/SEM INSTRUMENTS

Valery Ray(1**), Joshua Taillon(2*), Lourdes Salamanca-Riba(2***)

(1) PBS&T, Methuen, MA; (2) University of Maryland, College Park, MD (*) Present address: Material Measurement Laboratory, NIST, Gaithersburg, MD (**) vray@partbeamsystech.com, (***) riba@umd.edu

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

Outline

Challenges of FIB/SEM equipment evaluation
Quantifiable comparative testing approach
Design of tests targeting intended applications
Practical Examples
Summary

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

Challenges of Evaluating FIB/SEM Instruments

Complexity of translating application needs into

instrumentation requirements and evaluation criteria

There are no “bad” instruments out there
OEM engineers are highly skilled with demonstrations
Outcome of same operation for average user could be very different
“Canned Demo” approach by OEMs
Designed to demonstrate strong sides
Art of crafting specifications – “specsmanship”
Critical (for your application) performance parameters

could be “confidential”

Sometimes for a reason of not being known, defined, or ever tested

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

Quantifiable Comparative Testing Approach

Identify range of applications for intended usage
Translate application goals into instrumentation requirements
Design comparative tests, define evaluation criteria
Test descriptions and samples to all vendors as early as possible
Comprehensive evaluation based for intended use:
Quantifiable testing of critical performance parameters
Based on pre-defined evaluation criteria
Applications demo
Overall performance in 3D applications, TEM lamella prep, etc…
Two-day evaluation is reasonable to get all the data

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

Tests targeting intended applications

General Performance
Beam quality; System stability; Aperture repeatability
Patterning
Beam placement; Etching fidelity; Beam drifts and shifts
TEM lamella preparation
Throughput; Thickness uniformity; Ease of use; Automation; Endpoint
FIB Tomography 3D slice-n-view
Unattended runtime; Image quality; Throughput; Ease of use; Drift

Correction; Focus Tracking; Slice thickness uniformity; EDS integration

Imaging
SEM SE, SEM BSE, STEM BF, STEM DF, FIB SE, FIB SI…..

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

Samples for comparative evaluation

Performance Testing

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Application Testing

Same sample(s) to all vendors, require return of test sample(s) for independent analysis

SiO2 Etching Profiles Aperture Repeatability TEM lift-out Deposition Profiles

Epoxy-impregnated Solid Electrolyte Fuel Cell (SOFC), 2-phase ceramic SiO2 optical flat, ~24nm evaporated Al coating, silver paint around perimeter

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

General Performance – Beam Quality

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Basic test of ion beam quality: shape and homogeneity

Inhomogeneous beam Systematic high-current problem

Single aperture problem

Aperture size increase Aperture size increase Dose increase Aperture size increase Aperture size increase

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

General Performance – System Stability

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Basic test of tool stability

20 µm 20 µm

L-shaped single-line pattern and 21 beam burns on each arm with 1um offset along the line and 5 minutes delay between burns

1st pair

1 µm

HVAC failure Typical system drift “Quite not bad”

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

Critical Performance – Etch Placement & Fidelity

1um 1pA 3pA 10pA

Gas

0.2 nC/µm2 0.6 nC/µm2 1.8 nC/µm2

Shortest dwell time, -20% pixel overlap, x2 pattern repeats: (a) sputtering/GAE (XeF2) and (b) sputtering/depo (C, Pt, W)

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

Critical Performance – Etching Placement

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Patterning where intended with/without gas injection
C or Pt stripe e-beam deposited across lines, TEM lamella

prepared and STEM-imaged as part of application testing

Expected performance Visible artifacts

Aperture change shift

problem for multiple- current patterning

Shift due to gas

problem for site-specific deposition and GAE

Drift after aperture change

Problem for automatic patterning

Drift during line exposure

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

Critical Performance – Etching Fidelity

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Sidewall slope and No-Gas profile aspect ratio define polishing efficiency Al layer removal indicates beam tails damage to surface Narrowest cut defined by width

f a tip of No-Gas

etching profile No-Gas to GAE profile area ratio defines GAE enhancement No-Gas No-Gas GAE GAE

Al intact Al removed beam tails damage Al intact Al removed beam tails damage

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

Application Testing – SOFC imaging

SE BSE

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Side-by-side comparison of same sample imaging

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

Application Testing – 3D Reconstruction

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Fix experimental

parameters between vendors:

Run overnight, if possible
Results to evaluate:
Total running time (limited

by stability)

Usable acquisition

volume/hour

Acquired image quality
Output/ease of use of 3D

visualization software

Slice thickness Image resolution Dwell time Detector settings

Example of vendor visualization output

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10th FIB SEM User Group Meeting, NIST Gaithersburg MD March 2, 2017

Summary

Quantifiable testing approach enables comparative

evaluation of FIB/SEM instruments by collecting performance data under controlled conditions

Careful sample preparation, thorough test design, and demo planning
Seamless integration of performance tests with

applications demo facilitates comprehensive evaluation

providing OEMs opportunity to showcase strong features of the equipment
while allowing side-by-side comparison of critical performance parameters
There are no “bad” tools, but nobody is perfect either
Interpret test results in context of realistic application requirements

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