Transcript Document

EM Core Facility – Status Update
Steven Nutt, Lab Director
Presented at Biomedical Nanoscience Retreat
16 November 2007
Status of SEM Acquisitions
• 3 SEMs purchased
• Renovations to CEM building – December
start
• Acceptance tests scheduled for mid-January
• Delivery possible in February
Components of USC-JEOL MOU
(partnership)
• Support for postdoctoral fellow – 2 years
• Semi-annual workshops – focus on
techniques, applications
• Short course offerings
• Seat on JEOL corporate advisory board
• Demonstration site for JEOL – up to 12
visits/year
Instruments Purchased
JSM-6490-LV
JSM-7001F-LV
JIB-4500
The Site – CEM Building
Capabilities – JSM-6490-LV
• W filament with super conical lens optics
• Enhanced SE imaging
• 3.0nm @ 30kV
• 8.0nm @ 3kV
• 15 nm @ 1kV
• Low Vacuum 4.0nm
• Standard automated features
• Auto Focus/Auto Stigmator, Auto Gun,
and Auto Contrast and Brightness
• Large specimen chamber
• Asynchronous five-axis mechanically eucentric
stage with comp-eucentric rotation and tilt
• Multiple live image display
• Signal mixing
• Video capability (.avi files)
Low Vacuum SEM Imaging
Why low vacuum SEMs? The advantages far out weigh the disadvantages.
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Advantages
• Eliminates Charging without Conductive Coating
• Manage Non-ideal Samples
• Microanalysis without Coating (High kV and High Beam Current)
• Inhibit Dehydration
• In Situ Freeze Drying
• Non-destructive Testing; Preservation of Sample
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Disadvantages
• Primary Electron Beam Scatter
• Limits Performance (especially at low kV’s)
• Beam Skirt can Complicate X-Ray Analysis
High Vac ~10-4 Pa
Low Vac ~200 Pa
ESEM
~20 Pa
Low Vacuum
Secondary Electron Detector
Air
SE
Air
Air
SE SE
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Air
SE
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To Amplifier
Large Specimen Chamber
120 mm
Women’s Size 7 Running Shoe
Cell Phone
Samples as large as 300 mm in diameter by 90 mm tall can be placed in the sample chamber
and analyzed at our analytical working distance of 10 mm. Taller samples can be hung off the
side of the stage. Full coverage of 177 mm diameter sample with rotation.
Having the stage inside the chamber allows for accurate and fast placement of large and/or
heavy samples with no confusion as to the area being imaged.
Cyanobacteria Wet / Uncoated
Applications in Biology
Soil Worm – LV BSE Image
Applications in Biology
Observation of
Tetrahymena
by Freeze Drying in Low
Vacuum SEM
LV SE Images
JSM-7001F-LV
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Resolution
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SEI
1.2nm (30kV),
3.0nm (1kV)
Analytical 3.0nm (15kV, 5nA,
WD=10mm)
Magnification x10 ～ x1,000,000
Acc. V.
0.5kV ～ 30kV
Probe current 1pA ～ 200nA
Specimen stage 5-axis fully
automated mechanically
eucentric
Digital image up to 5120 x 3840
pixels
Multiple live display - 4 live
images of the same image field
with different signals
simultaneously
LV mode, 3nm (30 kV)
JSM-7001F-LV
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Thermal “In the Lens” FEG Source
Conventional E/T Detector
Conventional Solid State BSE
Analytical FEG >200nAmps of Beam Current
ACL for Small Spot Size at Large Beam Current !
EDS/WDS/EBSD/BSE/CL/e-Beam Lithography
Intuitive User Interface
JSM-7001F-LV - Applications
Thin (50 nm) rat brain section
4nm gold labeled cells