5702269-C Operation 6-3
Pinnacle™ Plus+ 10 kW
type, but typical low voltages for hard arcs are between 10 and 30 V. Thus a
reasonable voltage arc trip level might be 50 V. Note, however, that some target types
experience hard arcs at 100 V, so do not assume that 50 V is right for all processes.
Note: The recommeded V-arc trip level for low impedance metal targets is the default
value of 70 V.
To set the V-arc trip level, use the ARC menu on an active front panel or the Pinnacle
Remote Active Panel or AE Bus or PROFIBUS Command 10 (see the “I/O
Communication and Control” chapter).
For sputter applications the V-arc trip level should be set above 60 V; for bias
applications the V-arc trip level can be set below 40 V. A trip level between 40 V to
60 V can cause the unit to become unstable at start up.
FREQUENCY AND REVERSE TIME SETTINGS
Frequency and reverse time settings affect the arc and process behavior of the
Pinnacle Plus+ supply.
AE defines reverse time as the time that the pulsing switch is closed, that is, when no
power is transferred to the plasma. By action of the pulsing switch and output
inductor, output voltage is reversed. (See Table 3-4 on page 3-7 for reverse time
specifications.) Reverse time is only relevant during pulsing operation.
You need to adjust the ratio of sputter time and reverse time to optimize the rate and
film properties for your process. To do so, you will need a good oscilloscope and a
high voltage probe (2000 V rated) that has been calibrated for the scope you are using.
Note: AE recommends using a TEK 320, 380, 3054, 3012, 3032, or better, with a
1:100 P5100 voltage probe.
Frequency and reverse time settings can affect arc and process behavior in the
following ways.
• Higher frequencies will reduce the tendency to arc.
Note: Frequency is limited to 150 kHz when the pulse mode is set to be enabled
always.
• Short reverse times will increase the rate, but may increase the number of micro
arcs and possible hard arcs—especially if you are using a long output power cable.
• Frequency and reverse time define the maximum peak voltage at the cathode.
Setting high frequencies and long reverse times will raise the plasma voltage
during the sputter cycle. (Plasma voltage can be as much as double the DC
voltage).
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