INFICON MDC-260 Thin Film Deposition Controller - Manual (Page 56)

MDC-260 DEPOSITION CONTROLLER
PROGRAMMING AND CONTROLLER SETUP 4-20
Predeposit Time will result in unnecessary buildup of material on the shutter and
unnecessary material loss.
18. Rate Establish Time (0 to 99 seconds)
This parameter defines the time limit of the rate establish state. The Rate
Establish state occurs before the deposit state and is used to establish the correct
source power before the source shutter is opened. In the rate establish state the
crystal shutter is opened, the source shutter is closed, and the controller is
controlling source power to achieve the programmed rate within the Rate
Establish Error % for a period of 5 seconds. Once the rate has been held within
limit for 5 seconds, the controller will go into the deposit state. If the rate error
cannot be held within the allowed percentage error for 5 seconds, then the
controller will display a Rate Establish Error and the process will be halted.
For the Rate Establish function to work, the sensor must be located somewhere in
the vapor stream of the source while the source shutter is closed. The default
setting for this parameter is 0, which disables this function.
19. Rate Establish Error % (0 to 99%)
This parameter sets a maximum limit for the rate establish error, which must not
be exceeded for a five-second period during the rate establish state, in order for
the controller to enter the deposit state.
20. Deposit Rate (#1, #2, #3) (0.0 to 999.9 Å/sec)
Deposition Rate #1 defines the first deposition rate.
Deposition Rates #2 and #3 define the target rate that will follow the prior rate
ramp. This rate will continue until either the end of the layer or the beginning of
the next rate ramp. These parameters will not be displayed the rate ramps leading
up to them are not used (set to 100%).
21. Ramp (#1, #2) Start Thk (0 to 100%)
These parameters set the layer thickness percentage that will trigger the start of
the respective rate ramp. The MDC-260 supports two rate ramps. The
corresponding “Ramp Stop Thk” parameter sets the layer thickness percentage for
the end of the rate ramp. Finally, the next Deposit Rate parameter sets the target
deposition rate that the rate ramp will work towards.
Setting any “Ramp Start Thk” parameter to 100% disables that rate ramp.
Note: The ramp parameters can also be used as thickness setpoints for
triggering I/O events without actually using the ramping feature. For
example, if you wanted to trigger an event after 10% of the layer, your could:
• Set Ramp #1 Start Thk to 10%
• Set Ramp #1 Stop Thk to 10%
• Set the Deposit Rate #2 equal to Deposit Rate #1.
Then you would use the Deposit #2 State condition in the output's or action's
condition string that you wanted to trigger.
22. Ramp (#1, #2) Stop Thk (0 to 100%)