Xactix Xetch System

Xactix Xetch Xenon Difloride Etching System


Description

The Xetch is an isotropic etching system which utilizes xenon difluoride (XeF2) for etching silicon.  The Xetch is ideal for releasing structures from a silicon substrate and allows users to observe their samples through the duration of the etch. XeF2 shows very high selectivity of silicon versus photoresist, SiO2, silicon nitride, Al, Cr, and TiN where the  selectivity to silicon nitride is better than 100:1. The selectivity to silicon dioxide is reported to be better than 10,000:1 making it an attractive etching system for releasing chips fabricated in the CMOS MEMS process.

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Usage Policy

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Contact

Name Office Extension Email
Smitha Shetty HH 1209 Link Link

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Qualified Users List

Name Office Extension Email
Matte Zeleznik Akustica  
Michele Migliuolo Verimetra    
George Lopez      
Fernando Alfaro      
Brett Diamond Akustika    
Kyle Lebouitz Xactix    

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Standard Operating Procedures

New Procedures The rest of the page contains old procedures that need to be updated.
  1. Disable screen saver on monitor by touching any corner
  2. Turn on main valve of nitrogen tank located behind Xetch
  3. Press Load/Unload Sample button on touch screen. This will begin a venting an automated venting sequence which consists of three nitrogen purges and a nitrogen flush. During the nitrogen flush it may be necessary to tweak the regulator on the nitrogen bottle so that the pressure display reads ~90Torr
  4. Once the chamber is at atmospheric pressure load your sample.
  5. Turn on the microscope light source using the dial on the EKE microscope illuminator control box.
  6. Position the microscope above the chamber and check to see if sample can be observed. Reposition microscope or sample if necessary.
  7. Pump chamber down by pressing the pump chamber icon on the monitor.
  8. When the Main Menu screen is enabled select perform etch. Default settings should be 5 cycles, 60 seconds, 3T XeF2 and 0T N2. Adjust settings for desired recipe.
  9. Press start and observe sample. The etch can be stopped at any time by pressing the stop button. This will return you to the main menu.
  10. At the completion of the etch the main menu will reappear. Unload your sample by following steps III and IV.
  11. Pump chamber down and once the main menu screen appears turn off the nitrogen tank.

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Application Notes

  • Etch rates will vary depending on the amount of exposed silicon
  • The Xetch utilizes a pulsed etching scheme where a finite amount of XeF2 is introduced into the chamber during each cycles. For samples with small areas of exposed silicon a longer etch time may be advantageous while samples with large areas of exposed silicon may benefit from a shorter etch time.
  • Introduction of nitrogen to the recipe (~35T) can increase the selectivity of PR to silicon at the cost of a longer pump down times between cycles.

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Useful Links

Xactix

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Miscellaneous

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