Difference between revisions of "ToF-SIMS"
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(Created page with "==Overview== '''Time of Flight Secondary Ion Mass Spectroscopy''' or '''ToF-SIMS''' is an technique performed in a FIB to analyze the composi...") |
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'''Time of Flight Secondary Ion Mass Spectroscopy''' or '''ToF-SIMS''' is an technique performed in a [[Focused Ion Beam Microscopy | FIB]] to analyze the composition of surface layers. During analysis, a primary ion beam is rastered across the surface of a specimen to sputter atoms, molecules, and ions from the surface. Sputtered ions are attracted to and collected by a detector as they leave the specimen, which can identify ions or other charged particles according to charge and mass. | '''Time of Flight Secondary Ion Mass Spectroscopy''' or '''ToF-SIMS''' is an technique performed in a [[Focused Ion Beam Microscopy | FIB]] to analyze the composition of surface layers. During analysis, a primary ion beam is rastered across the surface of a specimen to sputter atoms, molecules, and ions from the surface. Sputtered ions are attracted to and collected by a detector as they leave the specimen, which can identify ions or other charged particles according to charge and mass. | ||
| − | + | ==Operation Bullet Points== | |
| + | *Tilt to 55 degrees | ||
| + | *Launch ToF-SIMS Explorer (TSE) | ||
| + | *Pump system below 7e-4 torr | ||
| + | *Turn off E-beam on FIB (in case of vacuum burp from SIMS vacuum chamber) | ||
| + | *Open SIMS gate valve in TSE (Hardware control tab) | ||
| + | *Ensure stable vacuum | ||
| + | *Turn E-beam back on | ||
| + | *Load set point voltages (Acquisition > Open TOF Instrument Control) | ||
| + | *Wait for voltages to stabilize | ||
| + | *Set field of view on I-beam (100 um for unknown) | ||
| + | *Set current on I-beam (100 pA for unknown) | ||
| + | *Acquisition > Acquisition Settings | ||
| + | **FIB image: 256 x 256 for unknown | ||
| + | **Binning: 2 x 2 for unknown | ||
| + | **Number of frames: 500 for unknown | ||
| + | **Group delay: 0 | ||
| + | **Pulse width: 1000 | ||
| + | **Choose output directory | ||
| + | **Choose file name (VERY SENSITIVE TO SPECIAL CHARACTERS! Underscores and spaces are ok. Filename MUST end in .h5). | ||
| + | **Store SEM Data: Dealer's choice but having extra data never hurt anyone | ||
| + | *Start acquisition (Triangle in circle button between Wrench and Stopsign) | ||
| + | *Beam will raster over field of view for specified number of frames (above) | ||
| + | *Live data in "Mass Spectra" tab and "Depth Profile" tab | ||
| + | *Ctrl-left click on peak in Mass Spectra to load into Depth Profile (can also pick a nominal m/Q value from dropdown next to Stopsign) | ||
| + | *Large ringing peak ~ m/Q=2 | ||
| + | *Right-click to select Y log scale | ||
| + | *cts/TOF-Extraction should not exceed 0.7 for measured peaks. If so, stop acquisition, reduce I-beam current, restart acquisition. | ||
| + | *After 500 frames, measure trench depth. If shallower than expected, reduce FoV or increase I-beam current. If deeper, increase FoV or reduce current. | ||
| + | *Lather | ||
| + | *Rinse | ||
| + | *Repeat | ||
| + | *When finished, zero voltages (Acquisition > Open TOF Instrument Control) | ||
| + | *Close valve (Hardware control tab) | ||
| + | *Close TSE | ||
==Equipment== | ==Equipment== | ||
Latest revision as of 21:13, 5 August 2025
Overview
Time of Flight Secondary Ion Mass Spectroscopy or ToF-SIMS is an technique performed in a FIB to analyze the composition of surface layers. During analysis, a primary ion beam is rastered across the surface of a specimen to sputter atoms, molecules, and ions from the surface. Sputtered ions are attracted to and collected by a detector as they leave the specimen, which can identify ions or other charged particles according to charge and mass.
Operation Bullet Points
- Tilt to 55 degrees
- Launch ToF-SIMS Explorer (TSE)
- Pump system below 7e-4 torr
- Turn off E-beam on FIB (in case of vacuum burp from SIMS vacuum chamber)
- Open SIMS gate valve in TSE (Hardware control tab)
- Ensure stable vacuum
- Turn E-beam back on
- Load set point voltages (Acquisition > Open TOF Instrument Control)
- Wait for voltages to stabilize
- Set field of view on I-beam (100 um for unknown)
- Set current on I-beam (100 pA for unknown)
- Acquisition > Acquisition Settings
- FIB image: 256 x 256 for unknown
- Binning: 2 x 2 for unknown
- Number of frames: 500 for unknown
- Group delay: 0
- Pulse width: 1000
- Choose output directory
- Choose file name (VERY SENSITIVE TO SPECIAL CHARACTERS! Underscores and spaces are ok. Filename MUST end in .h5).
- Store SEM Data: Dealer's choice but having extra data never hurt anyone
- Start acquisition (Triangle in circle button between Wrench and Stopsign)
- Beam will raster over field of view for specified number of frames (above)
- Live data in "Mass Spectra" tab and "Depth Profile" tab
- Ctrl-left click on peak in Mass Spectra to load into Depth Profile (can also pick a nominal m/Q value from dropdown next to Stopsign)
- Large ringing peak ~ m/Q=2
- Right-click to select Y log scale
- cts/TOF-Extraction should not exceed 0.7 for measured peaks. If so, stop acquisition, reduce I-beam current, restart acquisition.
- After 500 frames, measure trench depth. If shallower than expected, reduce FoV or increase I-beam current. If deeper, increase FoV or reduce current.
- Lather
- Rinse
- Repeat
- When finished, zero voltages (Acquisition > Open TOF Instrument Control)
- Close valve (Hardware control tab)
- Close TSE
Equipment
Focused Ion Beam Microscopes
- TESCAN S8000X FIB/SEM (EDAX)