SIMS SPECIFICATIONS
Click on a specific
component for further information.
Ion Gun
The ion gun
generates a focused ion beam used to sputter material from the sample.
Beam energy of 5
keV
 |
Operates on inert gases (Ar, Kr, or Xe) |
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Gases ionized with dual-filament electron impact source |
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Blanking plates |
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x, y deflection and rastering |
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adjustable
condenser lens settings for variable beam current |
Spot size of
25 mm
at 200 nA (analysis
mode)
Maximum beam
current of 20 mA
(for depth profiling)
Computer
switching between depth profiling and analysis mode
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High-speed pulser (5-200 ns width with ~2 ns rise and fall time) used to control blanking of ion beam |
Pumping System
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Click image to view larger version of pump and gauge screen panel. |
The pumping system (pumps and gauges) for the analysis chamber and ion gun are controlled and monitored by the computer.
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500 l/s turbomolecular pump (TMP) on chamber and 60 l/s TMP on ion gun |
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Turbo pumps backed by a 160 l/min roughing pump |
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60 l/s TMP on sample lock backed by 30 l/min roughing pump |
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Controller for load-lock TMP conveniently located on rack panel |
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Dual-filament computer controlled ion gauges |
Sample Loading
A four-compartment system allows high sample throughput.
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1” x 2” sample holders transferred from parking tray to main transfer arm by magnetic transporter |
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Samples transferred into analysis chamber by magnetic transporter |
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Pneumatic valve separates analysis and load-lock chambers |
Sample Manipulator
Click image to view larger version
A
computer controlled x, y, z manipulator is used for general
sample manipulation and imaging.
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25 mm travel in y and z, and 50 mm travel in x |
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5 mm step resolution |
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Images collected by rastering ion beam, rastering sample, or combination of both |
Time-Of-Flight Mass Spectrometer
The
ion optics are designed to maximize throughput for a variety of sample
configurations.
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Positive and negative ion modes |
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Large extraction gap allows analysis of samples with different thicknesses |
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Post acceleration improves mass resolution by greater than 4x |
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x, y steering and lens |
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Mass resolution (m/Dm) >800 at 41 amu and >2200 at 430 amu |
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Linear Time-of-Flight analyzer allows parallel detection of all masses |
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Optional reflectron analyzer available for higher mass resolution. |
Data Acquisition and Imaging
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Click image to view larger version of imaging screen panel. |
A dual channel plate assembly and high-speed time-to-digital converter (TDC) are used for data acquisition.
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Multi-stop TDC |
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Variable time resolution (time per TDC bin in multiples of 278 ps) |
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Data inhibit mode with variable start time and time range |
Computer Interface
The
majority of systems on the SIMS instrument are controlled and monitored by a
computer integrated LabView system.
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Monitors pirani gauge for roughing system and ion gauges for chamber and ion gun |
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Pop-up controls for pumping system and gauges, manipulator, pulse timing, gun rastering, and spectrometer voltages |
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Data acquisition program collects positive and negative ion spectra, converts time to mass spectrum with user-friendly calibration routine, and collects images by rastering ion gun, moving manipulator, or combination of the two |
Charge Compensation (Optional)
Click image to view larger version
Charge build-up on insulating samples is efficiently removed by flooding the sample with electrons between extraction cycles.
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Independently adjustable beam energy, beam current, and spot size |
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Beam energy variable between 50 eV to 1500 eV |
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Beam current range of 1 nA to 100 mA |
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x, y deflection |
Sample Viewing
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Click image to view larger version of this image of a penny in the SIMS system. |
The SIMS instrument is equipped with an optical microscope and camera for sample viewing.
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Optical microscope with x25 magnification |
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Color CCD video camera allows live display on PC monitor |
| Video frame grabber to capture and store images |
(865) 483-1113 (voice), (865) 483-3316 (FAX)