Joey’s Sputtering SOP.
Updated: 5 May 2005
by William R. Evans
Important: Please READ through all of the
instructions on this and all other SOP’s
which you are planning to use before
you do anything.
If you have not already done so: Record your
name(s), the date, the material being
Figure 0: The Run Book and Run Sheets.
sputtered, and substrate(s) on the run
sheet. [See Fig. 0]
Once you have reached as low a pressure as you can with just the turbo and roughing pumps:
6. Open the cryo pump.
To open cryo pump:
a. Make sure air valve is open.
(The air valve is open when the black handle is parallel to the tube. It is closed when
the black handle is perpendicular to the tube.)
b. Turn on pneumatic switch (light switch-looking thing).
[See Fig. 4]
(Cryo pump gate will open.)
Figure 4: Air Valve
and Pneumatic Switch
Figure 5: Cryo Pump
c. Close air valve.
Gate Valve Handle
d. Turn off pneumatic switch.
(The cryo pump gate valve handle will go slack.) [See Fig. 5]
After you have reached a base pressure, record what the base pressure was on the run sheet.
1. Check to see that all plugs and connections are secure and safe
(including RF connection to the chamber).
(Usually these are just fine.)
2. Turn on coolant water in back.
(2 valves) (Usually this is off.)
[See Fig. 1]
Figure 1
3. Turn on the power switch in the back of panel APCS-3. [See Fig. 2]
Figure 2
4.
Turn on the following switches: [See Fig. 3]
On CEX-2:
a. “Power” Switch
On AMNPS-1:
b. “Power On” Button
On APCS-3:
(Nothing)
On the Loading/Tuning Box:
(Nothing)
Bottom Panel:
d. “Control” Switch
When you turn the “Control”
Switch on, the buttons on
Source A will light up.
e. “Line” Switch
The “Line” Switch is behind
the metal cover.
On Source A:
c. “Power On” Button (White
Button) (This button should
already be on, since you
turned on the switches on the
Figure 1
Bottom Panel. The Blue
“RF Off” Button should also be already lit up.)
(In other words, turn on all the power switches on
the front except the HV Power Switch, the
Auxiliary Control Switch, the RF On Switch, and
the Incident Control Switch.)
Make sure the switches are set to their normal
configurations:
On APCS-3:
a. First switch (from the left)
set to Manual Power
Control
b. Second switch set to Local
Control
On the Loading/Tuning Box:
c. Loading to Manual
d. Tuning to Manual
On Black Box Below Source A:
e. Multimeter set to “PA Plate
Current 1 A”
f. PA Tuning set to about 65
Figure 3 (again)
5. Wait 2-3 minutes for the power source to warm up.
7. Close the cryo pump gate valve until it is ¼ open.
To open cryo pump gate valve to ¼ open:
a. Make sure air valve is open.
b. Turn on pneumatic switch (light switch-looking thing).
(Cryo pump gate will open.)
c. Close air valve.
d. Turn off pneumatic switch.
(Cryo pump gate handle will go slack.)
e. Use the cryo pump gate valve handle to close the gate valve until it is ¼ open.
If you want you can wedge the gear in place with a wrench.
13. If making a metal oxide or a metal nitride, add oxygen or nitrogen.
The main valve for the oxygen / nitrogen line is the “leak” valve
on the chamber, above the cryo pump. [See Fig. 10]
If you are using the MPA, open the leak valve until you reach
the desired gas partial pressure. (The correct partial pressure
will depend on the material you are sputtering. If you don’t
know, ask someone.)
Note: The MPA is a device which connects to the computer
and measures the partial pressures of the different types of
gasses in the chamber, where the other pressure gauges just
measure the total pressure. [See Fig. 11] How to use the
MPA will not be covered in this SOP.
Figure 10: The
Leak Valve
If you are not using the MPA, stabilize the pressure at about 7
or 8 x 10-3 torr.
Record how many turns the leak valve was opened on the run
sheet.
Figure 11: The MPA
Note: If you are depositing an oxide onto MOXTEK windows, we
have found that the oxygen plasma can react with the windows, causing them to break. We
have found better success with depositing a thin layer of the pure metal on the windows before
depositing the oxide. This protects the windows from the reactive oxygen plasma.
12. Open the argon valves. Valve 2 should be open until the gauge reads about 15 (you can adjust
this as needed).
Stabilize the pressure at about 3 x 10-3 torr.
(If you are depositing an oxide or a nitride, record the pressure after adding the argon and after
adding the oxygen or nitrogen.)
To open the argon tank valves, open the three valves on the tank,
starting with the one closest to the tank, then moving to the next
closest, etc. Note: This is how you open the valves on any gas
tank, not just the Argon. [See Fig. 8]
To close the valves on the tank, just close
the three valves starting with the one
furthest from the tank moving in reverse
order as how you opened them.
Figure 8: Gas tank
Remember: Open: “In to out.” Close:
valves, numbered in the
“Out to in.”
order to open.
The main valve for the argon line is
the Green “Nupro” valve behind
the chamber. This line also has a
Mass Flow Controller, which can
be controlled from the box above
the Crystal Monitor Readout.
[See Fig. 9]
This SOP will not cover how to use
the Mass Flow Controller.
Figure 9: The Green Nupro Valve (on the left)
and the Mass Flow Controller (on the right).
The mass flow controller is controlled on the
large brown electronics box, next to the power
box.
8. Turn RF Power Control Knob (On Source A) to a minimum. [See Fig. 6]
9. Turn the RF Power Button (Red Button On Source A) on.
Figure 6: Source A. The Power
control knob is the one in the
middle. The RF Power Button is
the second button from the right.
Figure 7: CEX-2. The HV
Power Switch is marked.
10. Turn the HV Power Switch (On CEX-2) on. [See Fig. 7]
11. Set Loading and Tuning to about 108.5 and 150.5 respectively.
Record the Loading and Tuning values on the run sheet.
14. Once you have stabilized the pressure, record the operating pressure on the run sheet.
(If you are depositing an oxide or a nitride, record the pressure after adding the argon and
after adding the oxygen or nitrogen.)
15. Input the film material # into the Crystal Monitor Readout.
[See Fig. 12]
To input film material #:
Press the “Film Number” button on the Readout.
Press the up and down arrows until the number on the
Readout matches the number on the post-it note next to the
readout.
Leave the Readout and it will set.
Figure 12: The Crystal
Monitor Readout
16. Turn the RF Power Control Knob (On Source A) to about
200 Watts (0.2 kW) of Incident Power (as read off of
the Incident Power readout On Source A).
[See Fig. 13]
17. Adjust the RF Power Control Knob and the PA Tuning
Knob (PA Tuning Only Slightly!), and most
importantly, adjust the working gas pressure, to
Figure 13: Source A. The
maximize the Incident Power and minimize the
RF Power Control Knob and
Reflected Power.
the Incident Power Readout
The Incident and Reflective power represent the
have been highlighted.
power going into the impedance source (the
sputter gun) and the power coming out from this
source back into the RF power supply, respectively. By maximizing Incident power
and minimizing Reflective power, the output power from the RF power source is
efficiently consumed.
Eventually, a plasma will be
created inside the chamber.
When a plasma is first
created, the reflected
power readout should drop
sharply (although it might
not be by very much). Also,
when there is a plasma in
Figure 14:
the chamber, you should be
Left: The Ion Gauge.
able to see a faint purple
Right: Looking down in the Ion Gauge. When a
glow in the chamber
plasma is created, you will be able to see a
through the glass Ion
faint, purple glow by looking down this tube.
Gauge. [See Fig. 14]
Once a plasma is created, sputtering off of the target has begun. You can adjust the
power until you get a good sputter rate (as read off of the Crystal Monitor Readout).
A good sputter rate depends on the material. For pure metals, this is about 1 or 2 Å /
sec. For oxides, this is about 0.2 Å / sec.
18. Record the sputter rate on the run sheet as read off of the Crystal Monitor Readout.
19. Once you have established a good rate, open the Sample Shutter and press “Start” on the Crystal
Monitor Readout.
To open the sample shutter:
Unscrew the lower knob.
Pull the side knob out.
Screw the lower knob back in.
To close the sample shutter, simply do the reverse as above.
The Crystal Monitor Readout will count the total film
thickness deposited after you pressed “Start” as measured
Figure 15: The Sample
from the crystal monitor (this will not be perfect, but it is a
good, rough value).
Shutter.
20. Once you reach the desired film thickness, close the Sample Shutter and press “Stop” on the
Crystal Monitor Readout.
21. Record the total film thickness on the run sheet as read off of the Crystal Monitor Readout.
22. Once you are done, turn the RF Power Control Knob to a minimum, and turn off all power
switches.
23. Close the argon (and oxygen or nitrogen if applicable) tanks.
(Remember to close the tank “out to in” as described in Step 12.)
24. Wait a couple of minutes so that the gas in the argon and oxygen or nitrogen lines is vented into
the chamber.
25. Tightly close the argon (and oxygen or nitrogen if applicable) valves (these would be the green
Nupro valve and the leak valve, respectively). (Also, if applicable, shut off the Mass Flow
Controller.)
26. Close the gate valve to the cryo pump.
To close cryo pump:
a. Remove wrench (if applicable).
b. With the air valve still closed, turn on the pneumatic switch (the light switch-looking
thing).
c. Open the air valve.
The gate valve should open completely.
d. Turn off the pneumatic switch.
The gate valve should close completely.
e. You can use the handle to pull the gate valve a little more tightly shut, just in case it did
not shut completely.
27. You can leave the turbo pump and the roughing pump running until you are ready to take the
sample out of the chamber.