Chapter 3 | Menus |
A description of each film parameter follows:
P Term: The proportional term sets the gain of the control loop. High gains yield more responsive (but potentially unstable) loops. Try a value of 50, 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 .5 to 1 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 to avoid oscillations.
Sensor 1: Allows quartz crystal Sensor 1 to be used for the selected film. If both sensors are assigned to a film, their readings are averaged. If two sensors are assigned to a film, and one fails, it is excluded from measurements.
Note: If a relay is assigned to Dual Crystal Shutter in the I/O Setup Menu, Sensor 1 becomes the primary sensor and Sensor 2 a secondary sensor. Sensor 1 is used until a crystal fail condition occurs. When Sensor 1 fails, measurement automatically switches to Sensor 2. Sensor 2 will be used until the process completes or is aborted. The next process run will return to Sensor 1.
Film Tooling: Compensates for sensor sensitivity to the selected material. Use Xtal Tooling in the System Params menu to compensate for each sensor individually.
Output: Selects the control voltage output that is active for the selected layer.
Pocket: Indicates which pocket
Max Power: The maximum output power allowed for the selected output. The Scale output voltage is a function of the deposition power supply input specifications, and is set in the System Parameters menu. Max Power controls the maximum power that can be used by this process layer.
Slew Rate: The maximum power change allowed on an output, per second. If power or rate ramps exceed this value, an error will occur.
Crystal Quality: The maximum allowed rate deviation, from the rolling average of the previous 16 rate readings. Each time the rate deviation exceeds the selected percent value, a counter is incremented. Each time the deviation is within the selected value, the counter is decremented (to 0 minimum). If the counter reaches 100 during a process, the process is aborted. Crystal Quality settings from 0 to 9 indicate:
