Quicklist for Thermal Evaporation
RevA 3/5/2004 S. McQuaide
Metal
Cr
Au
Ni
Cu
Al
Density
7.2
19.3
8.91
8.93
2.7
Z-Ratio
.305
.381
.331
.437
1.08
Current (A)
100
190
185
Notes
 Black gauge is for ion gauge readings (x10^_); red gauge is for TC1 foreline
valve readings (mTorr)
 Roughing valve and foreline valve should NEVER be open at the same time.
Either both valves should be closed or ONE open.
Prepare and Load wafer and metal source:
1. Look up the density and z-ratio for the metals to be evaporated
2. Fill a bottle of liquid nitrogen
3. Turn on water circulation (two valves; “on”=handle parallel to pipe)
4. Turn on system power (on back wall of the system)
5. Turn on roughing pump
6. Open Forline valve (ccw=open)
7. Wait for the TC1 reading (foreline pressure) to be about 50 mTorr
8. Turn on diffusion pump
9. Open air valve to vent the chamber to atmosphere pressure
10. Close air valve after checking copper hose at back of instrument to make sure no
more air is escaping
11. Raise the bell jar
12. Load wafer and metal source (boat and/or rod). Wear gloves.
13. Lower bell jar almost all the way
14. Wipe the rubber ring at the bottom edge of bell jar and the base
15. Lower bell jar all the way down
Pumping down chamber to MicroTorr:
16. Close foreline valve
17. Open roughing valve
18. Wait for the chamber barometer (on the shelf to the left of the chamber) to read less
than 100 mTorr. During this time, watch the foreline pressure. When it rises near 150
mTorr, close roughing valve and open foreline valve to pumping the foreline to around
50 mTorr, then switch back to pumping the chamber down.
19. Pour 3 or 4 funnels of liquid N2 to the cold trap
20. Make sure diffusion pump has been ON for 20 minutes
21. Close roughing valve
22. Open foreline valve
23. Open gate valve (BIG handle) to 100%
24. Wait for about half an hour. During this time, i) check whether there is frost around
the funnel channel; if not, pour in more liquid nitrogen; ii) Program the
crystal monitor; iii) when the barometer reads Zero, use IG to check chamber
pressure
Programming crystal monitor: Power ON, Auto mode, Prog mode (yellow
program indicator lights ON), Enter density and Z-ratio, input data in keypad,
Press Enter until layer 1 indicator lights are ON, Lock mode, Manual mode (man
power indicator light ON), Zero out, press layer 1.
Use of IG: Turn switchplate power OFF, dial to IG press, power on and zero out
IG, dial to Emission option, increase emission current to 3 mA, dial to IG press,
change to 10^5 or 10^6 range if reading is Zero (wait a while to get stable reading
after changing range), Get pressure reading down to 4uTorr or less, Change to
10^4 range, Turn down emission current to Zero, power OFF, Switch from IG
press to TC1, power ON.
25. Wait until IG reads several microTorr, turn switchplate power off and switch to
TC1; power on.
Thermal evaporation:
26. Check the power cable connected to the transformer box for the right metal
source and that the shuttle blocks the source (handle between tape marks). At time of this
press, cable #2 is for Cr rods; cable #3 for boats.
27. Push No.1 filament button
28. Rotate the current adjusting wheel knob to increase current SLOWLY to
appropriate current. (Current reading X 10 = actual current)
29. Open shuttle
30. Reading crystal monitor until expected thickness is obtained
31. Close shuttle
32. Turn down Filament current SLOWLY to Zero
33. Push No.1 Filament button once to turn off filament power. Disconnect cable and put
back into holder. For 2nd layer, reprogram crystal monitor, then go to step 26.
34. Close gate valve
Take wafer out and Shut down the system:
35. Turn off diffusion pump
36. Turn off crystal monitor
37. Wait for half an hour to let wafer cools down to room temperature
38. Open air valve to vent the chamber
39. Close air valve
40. Raise bell jar with hand on the metal mesh
41. Take wafer out and put back wafer holder
42. Take out metal sources
43. Lower bell jar almost all the way ; wipe rubber ring and base
44. Lower bell jar fully
45. Close foreline valve
46. Open roughing valve
47. Wait until the barometer reads less than 100 mTorr
48. Close roughing valve
49. Turn off roughing pump
50. Turn off system power
51. Turn off water (both valves)
52. Done
Contacts for this machine:
Tai Chen 221-5388 tcchen@u.washington.edu
Sarah McQuaide 616-1394 smcquaid@u.washington.edu