The Ion Beam Etcher has a collimated monochromatic broad-beam ion source (Kaufman type) that can be used for ion etching / ion milling. The beam diameter is 4 cm. Working pressure is 3-4 e-4 mbar. The maximum beam current is 10 mA and the maximum energy is 1500 eV. For resist processing typically low energies are used to avoid damage to the imaging resist.

The system is equipped with a loadlock with a knudsen cell so that a deposition step can be performed immediately after etching (a so called self aligned process). The substrate table can be tilted and can rotate in the tilt plane.

Change the input source on the display to DisplayPort if it isn't on the correct input source.
Switch over USB cables of mouse and keyboard.

• If rotation is required (to avoid 'ears') use the holder with the rotation option.
• Glue the sample on the holder with silver paint (Dry for ~10 mins)

• Turn off the Penning pressure gauge, by pressing HV.
• Press TM to switch to the Pirani pressure gauge.
• Turn off the turbo (set switch to down position)
• Close valve to the rotary pump (attached to the turbo).
• Switch to the DM pressure gauge.
• Wait until the turbo has slowed down (you can let in some gas to speed this up, 1e-1 mbar max).
• Vent the chamber to atmospheric pressure and close venting valve.
• When the chamber is at atmospheric pressure, check if shutter is closed and open the chamber.
• Slide the sample holder onto the cooling stage and close shutter.
• Check rotating table (max 1 volt - although 0.5 is usually enough, current 20mA or so)
• Close the chamber.

• Open the valve to the rotary pump (attached to the turbo).
• Flip TP switch up to start the turbo pump.
• At 10 mbar switch to TM pressure gauge.
• Make sure green valves is closed, set black valve SLOWLY to ““IBE””, Keep an eye on the pressure while doing this. Never turn this to “RIE”, because this is an unconnected conduct, which will cause air to flow into the Argon conducts.
• Set MFC setpoint to 0 with the software.
• Set valve override to OFF. You're now able to write a setpoint to the MFC.
• Slowly increase setpoint in steps of 0.5% to pump away left over Ar in the line. Open MFC fully (valve override OPEN) when pressure doesn't increase anymore.
• Put valve override to 'OFF' and put the setpoint to 0.
• Wait (~30 mins) until pressure is <1.0e-5.

• Cool with N₂ if needed (Resist can become too hard to remove if not cooled, especially if you etch longer than 4 min).
  • Check if N₂ barrel needs to be refilled.
  • Attach Hose
  • close lit of N₂ barrel
  • close gas outlet (warning: danger of explosion if all outlets are closed) and wait
  • open liquid outlet
  • the tubes should fill and due to the cold condense and freeze on the outside (if you shake the barrel a bit, the N₂ heats up and the barrel should pressurize faster).
  • When the N₂ sputters out the exhaust, close the liquid outlet.
  • open gas outlet. (You can optionally open the lit).
• Turn on power to rotating table (1 volt), otherwise the rotation might not work at low temperatures.
• Note the base pressure in the Logbook.
• Open green valve
• Set Argon pressure to 2,5e-4 to 4.0e-4 mBar with program on the computer
• Turn on main power for ion beam (watch safety fuse)
• Select recipe (#10)
  • press 'select recipe'
  • press '+' and '-' to select the right recipe on the LCD.
  • press 'enter'
  • press 'view recipe'
• Make sure the ion canon shutter doesn't touch the sample holder.
• Press “source” on control panel (this step is optional, it is done automatically once you do the next step)
• To start etching press “beam” on control panel
• Elapsed time is shown on display. You must stop the system manually once the desired etching time is reached.
• Open shutter, start the timer
• Press “source” to stop
• Turn off main power for ion beam.
• Turn off rotating table.

• Let ion gun cool by increasing Ar flow (1e-2 mbar, 2 min)
• If you cooled your sample, let the sample warm up for at least 15 min (08-04-21: Or do 5 min and do another 10 mins at 1 bar) while pumping (this to avoid possible pollution of oil or other things on your priceless sample).
• Close green Argon valve.
• Let the Argon be pumped out the conduct, increase the MFC setpoint slowly to 100% in steps of 5%. When the pressure doesn't is stabilizing open the MFC fully.
• Wait a few minutes and close MFC.
• Set black Argon valve to neutral
• Turn off turbo pump
• Close valve to the rotary pump
• Vent the system slowly with the “vent” switch (start with 1 sec)
• Wait until turbo pump has decelerated
• If you cooled with N₂, you need to let your sample stay inside the lock at close to 1 bar (~10 mins) to let the sample holder warm up. As long as it is below 0, Ice may form, once you remove it.
• Remove sample holder
• Pump chamber down for a few minutes with rotation pump (no turbo).
• Turn on the Turbo (TP switch)
• Remove sample, clean sample holder with Silver paint dilutent, acetone and/or IPA.
• Fill in the logbook

• Pressure Gauges:
  • (10-1000 mBar) The high pressure gage 'DM' can be selected manually.
  • (Below 10 mbar - “pirani”) you can switch to 'TM'.
  • (High Vacuum - “penning”). The system will (should) automatically switch to the lowest pressure gauge 'PM'. You can turn off the high vacuum pressure gauge 'PM' “penning” by pressing 'HV'.
  • You can see which pressure guage is active at the display indicator directly above it.

Pressure control unit: Leybold and Hereaus Combivac CM33.
The pressure control unit will switch automatically between the different pressure sensors.

DM (Capacitance gauge, 1000 to 10 mbar): Leybold CM1000
TM (Pirani gauge , 10 to 10e-3 mbar): Thermovac TR 216 Leybold
PM (Penning gauge , 10e-3 to 10e-8 mbar): Penningvac PR36

Nb 20050311 based on 7:30 sputtering in UHV, 220 mA, 4 ubar, 0 angle, 258 A Xtal

ibe-logbook.xls