Metal Evaporation
Instructions:
- Start
with the Roughing(R) valve closed, the Foreline(F) valve closed, and the
diffusion pump shut down.
- Open
both the inlet and outlet valves on the wall for the chilled water flow to
the diffusion pump.
- Turn
on the mechanical pump, and open the F valve.
- Turn
on the diffusion pump, first by enabling the roughing pump switch(listen
for an engaging clicking sound) and
then press the diffusion pump power button. Check to see that the diffusion pump is
starting to warm up.
- Open
the bell jar. (Remove the lead bar on top.
Open the nitrogen source valve on the right side of the
evaporator. Open the nitrogen vent
valve on the left side of the evaporator.
Close it once the jar is open.
- Load
samples, the materials to deposit, and check the electrical contact of the
basket, boat or source. Check the
position of the shutter to ensure that it does not block the
deposition. (basket 1-4, boat 1-3).
- Close
the bell jar, first cleaning the base cylinder and the gasket on the
bottom of the bell jar. Also clean
underneath the base cylinder if necessary, and lightly grease the rim if
needed.
- With F
closed, open R, holding down the bell jar manually or with the lead
weight. Wait until TC2 reads ~100
mTorr (1.0E-1 Torr).
- Close
R and open F. Wait until TC1 reads ~150 mTorr (1.5E-1 Torr).
- While
waiting, get liquid nitrogen and connect it to the cold trap. Turn on the cryomiser by flipping the
switch to “Auto”. If the nitrogen
pressure is initially below 5, open the valve to supply nitrogen to bring
it up to a 10-15 psi level. Turn
off the valve after that to avoid overpressure.
- Wait
until the cold trap box is filled, and the solenoid switch goes off.
- Check
TC1 and TC2 pressures. If OK then
turn the Hi-Vac crank valve all the way counterclockwise.
- Wait
about an hour until the chamber pressure comes down to ~E-6 Torr. Check this with the ion gauge by
pressing the “emis” button. Wait
for it to heat before reading the pressure.
- Program
the crystal monitor:
- Press
“PG”
- Enter
the density, z-ratio, tooling factor, thickness limit, and final
thickness. Thicknesses are in
KA. Tooling factor is normally
130%. For Al, r = 2.70, z-ratio = 1.08, thickness
limit should be just a bit higher than the final thickness.
- Cr: r = 7.20, z-ratio = 0.305
- Au: r = 19.3, z-ratio = 0.381
- Press
“PG”
- Turn
filament on.
- Apply
voltage slowly, avoiding the max fuse current of 15A.
- Hit
the Start button and check the monitor.
Hit Stop, Zero, and Start on the crystal monitor controller and
open the shutter.
- Close
the shutter when the monitor shows thickness has reached desired value.
- Cut
the power, turn off the filament, and the crystal monitor.
- Close
the Hi-Vac valve, turning fully clockwise.
Turn off the Cryomiser, and the ion gauge.
- Open
the bell jar, unload samples, and clean the window.
- Close
the bell jar. Close F and open
R. Wait until TC1 reads 150 mTorr.
- Close
R and open F. Turn off TC
gauge. Wait until the cold trap box
completely warms up to room temp, and then turn off the diffusion pump.
- Close
both the inlet and outlet valves on the wall for the chilled water flow to
the diffusion pump. Close F and
turn off the mechanical pump.
Confirm system is shutdown.