INFICON Guardian EIES Controller - Manual (Page 136)

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Guardian Co-Deposition Controller Operating Manual
Create a One-Layer Test Process: Create a new process that has a single film as
its only layer, and select it as the current process. Set the film's Initial Rate to your
desired rate and Final Thickness to a large value, say 10X your desired Final
Thickness. Select the proper Sensor(s), Output, and Material. Set Max Power to
100% and Slew rate to 100%. Set Error Action to Ignore.
Test the Setup: Press Auto/Manual to start the layer in Manual mode. Slowly
increase to a power of 10%, and verify that your power supply output is about 10%
of full scale. Continue to increase the power until a Rate(Å/s) above 0 is shown.
Again, verify that the power supply output agrees with the Power(%) reading. If the
readings don't agree, check your wiring and process setup. In particular, verify that
the System, Outputs, Full Scale voltage agrees with your power supply input
specifications.
Determine Open Loop Gain: Slowly adjust the power until the Rate(Å/s) reading
approximately matches your Initial Rate setting. Record the Power(%) reading as
PWR
DR
(power @ desired rate). Slowly lower the power until the Rate(Å/s) reading
is just at (or near) zero. Record the zero rate Power(%) reading as PWR
0R
.
Determine Open Loop Response Time: Calculate 1/3 of your desired rate
(RATE
1/3
), and 2/3 of the desired rate (RATE
2/3
) for this layer. Slowly increase the
power until Rate(Å/s) matches RATE
1/3
. Get ready to record the loop's response to
an input change. Quickly adjust Power(%) to PWR
DR
. Measure the time for the
Rate (Å/s) reading to reach RATE
2/3
. You may want to do this several times to get
an average response time reading. Displaying the Rate graph will also help. Twice
the measured time is the step response time, TIME
SR
. TIME
SR
is typically 0.7 to
1.5 seconds for E-Beam evaporation, 5 to 20 seconds for thermal evaporation.
Press Abort Process, then Manual/Auto to return to Auto mode.
Set Preconditioning: The power level you recorded as PWR
0R
is the power where
deposition just begins. That is a good value for Ramp 1 power. PWR
DR
, or slightly
less, is a good value for Ramp 2 Power. This will eliminate a large step change
when entering the deposition phase. Enter Ramp 1, Soak 1, Ramp 2 and Soak 2
Times to ensure the material can heat up slowly and outgas properly.
Set PID Values: In the Edit Layer, DEPOSIT tab set P Term =25, I Term = TIME
SR
,
D Term =0. Assure that all CONDITION values are set to zero. Save the values and
close the Edit Layer dialog box.
Press START and observe the Power graph. The power should rise from 0%, and
stabilize near PWR
DR
with little ringing or overshoot. If there is more than about
10% overshoot, lower the P Term. If the time to reach PWR
DR
is very slow, increase
the P Term. A lower I Term will increase response time, a higher value will eliminate
ringing and setpoint deviations. It is unlikely you will need any D Term.