Standard Operating Procedure

STARTING THE OPTICAL PROFILER 

• Make sure sample stage is EMPTY 
• LOG IN to the instrument 
• Launch “Vision” software from desktop shortcut 
  • If the software asks you to verify an empty stage, do so and click OK. The optics turret will then rotate back and forth for self-check. 

SETTING UP INSTRUMENT FOR USE 

• Open MEASUREMENT OPTIONS from the tool bar 
• Select VSI or PSI as measurement type, as described above. VSI is good to 2nm vertical resolution; PSI has a more narrow range but is good to 0.2nm resolution. 
• Choose the 10X objective lens, and the 0.55X FOV settings. 
  • This gives the largest field of view for initial sample location and rough focus. 
• Click OK to close Measurement Options. 

LOADING SAMPLE 

• Make sure lenses and sample chuck are more than two inches apart. 
• Load a CLEAN and DRY sample on to the sample chuck. 
  • The vacuum chuck uses a porous stone than can be easily damaged by dirty or wet samples. 
  • The vacuum chuck can be actuated with the manual vacuum valve. 

SETTING UP A MEASUREMENT 

• Open INTENSITY from the tool bar 
  • You should see a flashing light from the objective, projected on the sample chuck. Use the XY stage to move your sample under the flashing light. 
• Open Z-AXIS control from the Intensity window 
  • Next, you will be lowering the objective towards the sample. Watch the lens and the sample, not the computer screen! 
  • Move the lens close (~5mm) to the sample VERY CAREFULLY. 
  • Now, watch the computer screen and locate your sample by reversing the lens travel direction to move the lens UP and AWAY from the stage. This way, you will not crash the lens into the stage while observing the image on the computer screen. 
• Once you sample comes into view, choose a very slow Z-AXIS speed and focus until you see fringes. 
• Open MEASUREMENT OPTIONS again from the tool bar. Choose VSI or PSI for your measurement type. 
  • Choose your objective, but make sure that NOTHING IS IN THE WAY of the sample if switching to 50X. This includes sample holders, tall sample parts, etc. 
  • Choose your FOV objective multiplier. 
  • Go to VSI Options or PSI Options tab as appropriate. 
    • VSI Options: 
      • Back Scan: Leave at default 5μm 
      • Scan Length: Approximate desired depth of scan. It’s better to overshoot by 20% than to undershoot. 
      • Modulation Threshold: Leave at default 5%. 
      • Everything else should be default. 
    • PSI Options: 
      • Modulation Threshold: Leave at default 5%. 
      • Everything else should be default. 
  • Click OK to exit Measurement Options. 
• Return to the INTENSITY window. 
  • Use the Z-axis to get fine focus on sample; fringes will appear. 
  • Use two manual tilt knobs to align fringes perpendicular to step or primary feature. 
  • Remove tilt until only you have only a few fringes (VSI) or one fringe (PSI) visible. 

TAKING A MEASUREMENT 

• Click NEW MEASUREMENT from toolbar. 
  • Measurement will proceed. 
  • Adjust scan length for optimal image and rerun New Measurement. 
  • Right click on image and choose Analysis Options for different tilt compensation. Modal Tilt will usually be the best option. 

DATA ANALYSIS 

• Use any of the numerous options to analyze and view your data. Save data and images as appropriate. 

CLEANING UP 

• Use the Z-AXIS control to move objective lens UP and AWAY from sample, again while watching the sample, not the computer screen. Move at least two inches from sample. 
• Remove sample. 
• CLOSE all open windows and exit Vision software and log of the tool.