INFICON STC-2000A Thin Film Deposition Controller Operating Manual - Manual (Page 32)

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STC-2000A DEPOSITION CONTROLLER
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Averaging: In addition to the typical configuration of 1 crystal sensor, 1 oscillator, 1 control voltage
output, the STC-2000A can utilize (by means of the 2
nd sensor channel) two sensors to acquire evaporant
stream data simultaneously at different locations, insuring greater repeatability of process control as well as
better process control (compensating for the vicissitudes of the evaporant stream in location and in time).
A number of user programmable parameters effect dual sensor depositions. Review Source Sensor Map
chooses the two sensors that are part of the multiple sensor group. Since each sensor has a unique
parameter group, programming 2 crystals as active automatically invokes an averaging mode. Lost
channels during averaging are handled by menu programmed alternatives (Main Menu/Review SS
Maps/Channel Drop Filter Mask).
Although the STC-2000A cannot control multiple depositions (multiple sources as is the case with
co-deposition), it can maintain 2 sources such that one source output is controlled while other source output
can be maintained at a non-zero power
level. This would provide the ability to precondition other materials
that could become activated (controlled) when the currently controlled source reaches its preset conditions.
In other words, multiple source outputs can be providing some level of output to multiple power supplies
while deposition control can be focused on a single source output (moved) between the two. The
preconditioning mentioned above would include the soak phases of the deposition process cycle. The soak
phase is (or soak phases are) characterized by power being maintained at a constant level.
Note soak power levels in deposition cycle
Rise
1
Rise
2
Soak
1
Soak
2
Shutter
Delay
Deposit Rate
Ramp
Deposit
2
Idle
Ramp Idle
SECTION 2.XX page 32 of 292