INFICON SQM-242 Thin Film Deposition Controller Card Software Operating Manual - Manual (Page 43)

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SQS-242 Operating Manual
Ramp Time: The time (in seconds) to ramp to the new rate. If the rate ramp is too
fast, a PID control error may be generated.
New Rate: The new deposition rate setpoint for the selected layer.
3.5.1.3 Deposit Tab
The Deposit tab contains parameters that directly affect the deposition phase of
the process cycle. See
Figure 3-11 .
Figure 3-11 Deposit tab
P Term: Sets the gain of the control loop. High gains yield more responsive, but
potentially unstable loops. Try a value of 25, then gradually increase/decrease the
value to respond to step changes in rate setpoint.
I Term: The integral term controls the time constant of the loop response. A small
I term, say 1 to 3 seconds, will smooth the response of most loops.
D Term: The differential term causes the loop to respond quickly to changes. Use
0 or a very small value (.1 x I Term) to avoid oscillations.
Shutter Delay: It is often desirable to assure stable process control before the
substrate shutter opens. Enabling shutter delay requires that the system reach the
programmed shutter delay Accuracy, and maintain that accuracy before deposition
begins. If the accuracy is not reached within Wait seconds, the process halts. If