AJA ICP Argon Ion Mill Etcher
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LEFT: schematic of the inductively coupled plasma (ICP) argon ion source, user sample (red) is placed to the right of the accelerator grid. “Neut.” Refers to the neutralizer. RIGHT: schematic of the Hiden Ion Milling Probe using Secondary Ion Mass Spectrometry (SIMS) for etch End Point Detection (EPD).
Tool Highlights
- Direct physical milling of thin and thick films using argon atoms.
- Ion beam source : inductively-coupled argon plasma, accelerated up to 900 V in a 14cm broad beam with currents up to 620 mA (Kaufman & Robinson, Inc.).
- Ar+ ions neutralized using a matched electron beam current before reaching the sample.
- water-cooled rotating sample carrier can be oriented 0-90 degrees from normal beam incidence.
- Secondary ion mass spectrometer (SIMS) mounted on the system can be used for manual or automatic endpoint detection (EPD) of milled material by discerning elements based on charge/mass ratio of positive ions (Hiden Analytical).
- Sample load-lock system saves time with processing.
The shared carrier and mask wafers are dirty since they collect all the sputtered material from users' samples.
If you care about contamination of your sample due to re-sputtering of material, you need to provide your own carrier and masks.
- To order your own "rotary substrate carrier" from AJA International (www.ajaint.com) (email), use the part # SH-H2O-R-ASSY .
- About Si wafers for masking the sample holder
About etching gold (Au): please discuss with Neil or the BNC staff in charge before etching Au.
Sample chuck cooling during etch: Note that thick films require high etch rates (and hence high amounts of heating), so this may mean one needs to load the sample directly on the chuck by venting the chamber (instead of using load lock). This will permit users to apply more torque and get better cooling of the chuck. However, it requires special training.
For EPD, note that argon atomic mass is the same as MgO, so the EPD is not able to sense (ionized) MgO in the large Ar ion background.