Hyperspectral Infrared Characterization of Extremely Thin Films with 10 nm Spatial Resolution
TFUG, Oct. 17, 2019
Sung Park, [email protected]
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Molecular Vista Inc (Introduction to the Company)
2
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
Chemical Mapping: Elemental Analysis via Electron Microscopy
http://www.nanolabtechnologies.com/TEM-STEM-EELS-EDShttps://www.aif.ncsu.edu/tem-lab/
Image credit: North Carolina State Univ. Analytical Instrumentation Facility Image credit: Nanolab Techologies
Atomic Resolution Elemental Mapping on SrTiO3 crystal by Super X EDS (EDX) system on Titan 80-300 Aberration Corrected Scanning Transmission Electron Microscope
• Advanced capability for elemental mapping• Atomic-scale resolution in certain circumstances
Elemental mapping of a device structure by EDS (EDX)
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
FTIR: Infrared absorption “chemical fingerprint” spectrum
https://en.wikipedia.org/wiki/Fourier_transform_infrared_spectroscopy#/media/File:FTIR_Interferometer.png
Image credit: Wikipedia Image credit: Mudunkotuwa et al., Analyst 139, 870-881 (2014).
• Detailed spectra for analysis and identification of molecular materials• Spatial mapping resolution limited by optical diffraction limit (~ 1 mm)
Detailed absorption spectrum – chemical “fingerprint”
FTIR apparatus
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
PiFM Measurement – Sideband BimodalTM
f0 – 1st cantilever resonancef1 – 2nd cantilever resonancefm – laser pulse frequency
Spectrum acquired with PiFM
f1 – fm = f0
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
Agreement between Nanoscale PiFM and Bulk FTIR Spectra
6
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
Topography
100 nm
47.4 nm
0.0 nm
15
1015
2025
30
Fiber
Resin
500 mV
15
9
Wavenumber (cm-1)
Ph
oto
-in
du
ce
d F
orc
e
8009001000110012001300140015001600170018001900
8281738
15081095
1264
16 - 30
1 - 8
Interfacial Chemistry (QCL: 760 – 1960 cm-1)
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
Exceptional Spatial Resolution in Chemical Mapping
Ps-b-PMMA Block Copolymer, L0 = 22 nm
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
Surface Sensitivity
l2
triple helix collagen
1 ~ 2 nm
Sample: Courtesy of Jinhui Tao, PNNL
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
Complements other Analytical Techniques
IR PiFM Raman FTIR TOF-SIMS XPS TXRF SEM/EDS TEM Auger
Species Detected
M.I. M.I. M.I. M.I. M.I. E.I. E.I. E.I. E.I.
Imaging/Mapping Yes Yes Yes Yes Yes Yes Yes Yes Yes
Lateral Resolution < 10 nm > 0.5 mm > 10 mm > 0.2 mm
10 mm – 2 mm
~ 10 mm1 nm*
0.5mm EDS 0.2 nm > 10 nm
Depth Probed 20 nm > 500 nm 1 mm 1 nm 10 nm 10 nm 1 mm ~ 100 nm 10 nm
* Imaging M.I. Molecular information E.I. Elemental information
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
Semiconductor Applications
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
Area Selective Deposition (ASD)
Cu SiO2 Cu SiO2 Cu SiO2 Cu SiO2
SAM
Cu SiO2 Cu SiO2
ALD Layer
Ideal Selective Area Deposition
Real World Selective Area Deposition
• SAM Layer• Inhomogeneous and incomplete coverage• Intrusion to SiO2 area, some of which desorb during ALD process
• ALD Layer• Inhomogeneous coverage
Difficult to verify processes with existing tools
metal oxide
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Characterization of EUV Resist Exposure
l2
Chemically amplified photoresist (tBOC)
Exposed to EUV light (l = 13.5 nm) at
ALS Lawrence Berkeley National
Laboratory.
Exposure creates shrinkage, resulting
in depression in topography (a).
topography phase
PiFM
Blue – Unexposed
Orange – Exposed
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
Visualization of Local Strain
Topography
200 nm
11.8 nm
0.0 nm
SiGe
SiO2
SiGe
SiO2
1 3 5 7
2 4 6
PiFM 1122 cm-1
morestrain
lessstrain
1 3 5 7
2 4 680010001200140016001800
Ph
oto
-in
du
ce
d F
orc
e (
Arb
. U
nit)
10871122
1
2
3
456
7
SiGe channel area
a)
SiO2
SiGe
wavenumber (cm-1)
400 nm
CombinedSiO2 @1113 cm-1
SiGe @900 cm-1
b)
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
Topography
500 nm
45.4 nm
0.0 nm
Phase PiFM
protective layerPET substrate
silver nanowires
Imaging Buried Conductive Layer
hint of a wire
Copyright © 2019 Molecular Vista – All Rights Reserved – Proprietary and ConfidentialApplications Lab
120.0 µV
0.0 µV2.00 1.50 1.00 0.50 0
µm
2.00
1.50
1.00
0.50
0
120.0 µV
0.3 µV2.00 1.50 1.00 0.50 0
µm
2.00
1.50
1.00
0.50
0
Working with 1D/2D Materials
100 nm
691 µV
335 µV100 nm
2.90 nm
0.00 nm
PiFM @ 1122 cm-1Topography
PiFM @ 800 cm-1
topography500 nm
Graphene
11.1 nm
0.0 nm
ML
MoSe2
PiFM @ 683 nm PiFM @ 683 nm
single wall carbon nanotube
semiconducting metallic
Ab
sorp
tio
n
wavelength (nm)
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Summary
17
• AFM IR technique, PiFM, is introduced.• PiFM measures sample’s complex polarizability via mechanical force detection.• It provides for exceptional spatial resolution (< 10 nm), excellent surface sensitivity
(monolayer), and ease-of-use.• Vista-IR is a turnkey PiFM systems with visible to mid-IR lasers.• Vista-IR can chemically map and identify organic and inorganic materials via
localized IR spectrum (from 10 nm x 10 nm region by monolayer volume).• PiFM is useful for many semiconductor applications.
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