Many papers have touted the benefits of pulsing for sputtered plasma applications. Photographs show that crossing 0 V on a regular basis produces films that are flatter and denser than with straight DC. This application note provides guidelines for optimizing pulsed sputtering applications to achieve the highest rate and the best film qualities with the least amount of arcing in the plasma.

OPTIMIZING PULSED SPUTTERING APPLICATIONS
Adjust your process to achieve the highest deposition rate, best film qualities,
and lowest arc rate.
D. Pelleymounter, Advanced Energy Industries, Inc.
Many papers have touted the benefits of pulsing for
sputtered plasma applications. Photographs show that
crossing 0 V on a regular basis produces films that are
flatter and denser than with straight DC.
This application note provides guidelines for optimizing
pulsed sputtering applications to achieve the highest
rate and the best film qualities with the least amount
of arcing in the plasma.
Initial Setup
The output cable of the power supply
should be 3 m (10’) or less in length for best
results. Thirty feet is the maximum length.
Longer cables result in more stored energy
Table of Contents
and increase the time to attain voltage
reversal at the chamber.
Initial Setup
1
you are sputtering, voltage-wise. Set the arc
trip level parameter to 50 V or 10% of your
Disclaimers2
•Ascent® Series
Pinnacle® Plus+ Series
Applications
• Pulsed sputtering
Who Benefits
• Process engineers
You should already have an idea of where
Procedure2
Products
working voltage—whichever is higher. This
is usually a good starting point, and the level
will probably increase from here.
Start the arc off-time at around 10 µsec.
This may need to increase for larger
magnetrons, as it takes longer for the
arc charge to decay.
Procedure
The following procedure provides the most on-time, which allows the highest rate, because no sputtering takes place during the off-time.
Tuning out arcs as described below also enables the best film qualities.
1. Start at 20 kHz. Most plasma processes will not benefit below this frequency.
2. Set the duty cycle as close as possible to 50%.
3. Turn on the output power at a low power that is in your comfort zone.
4. Increase the frequency so any arcing subsides or at the very least minimizes, if the process is arcing heavily.
5. Adjust arc trip level and arc off-time to give the best arc handling for your particular process, if necessary.
6. Ramp up the power to the desired plasma process level, if steps 4 and 5 have resulted in acceptable plasma stability.
7. If arcing occurs at the process level, increase the frequency until arcing subsides.
8. Adjust the arc trip level and arc off-time parameters again to achieve good stability, if necessary.
9. When the process is stable, reduce the off-time parameter until arcing starts to occur.
10. Increase the off-time parameter just until arcing goes away.
Disclaimers
• The above procedure is only a guideline. All chambers, magnetrons, and processes can and do have unique behaviors
in any given situation.
• The big three noble metals—gold, silver and platinum— do not benefit from pulsing. They all sputter nicely with straight DC.
• ITO processes work best at a low voltage—200 V and less. The best way to do this with pulsing is to run at as close to 50% duty
cycle as possible. Adjust the frequency, starting at 50 kHz and increasing it while watching the power supply voltage until
a low-voltage “sweet spot” is found. A 200 V level probably will not be possible, but the lower the voltage, the better ITO runs.
Al2O3 sputtered with the aid
of an AE® pulsed-DC product (left)
Al2O3 sputtered without the aid
of a pulsed-DC product (right)
(Photo source: Centre for Advanced Materials and Surface Engineering, University of Salford, U.K.)
To view AE’s DC and pulsed-DC portfolio, visit:
www.advanced-energy.com/en/DC_Power_Systems.html
To view AE’s complete product portfolio, visit:
www.advanced-energy.com/en/Products.html
Advanced Energy Industries, Inc.
1625 Sharp Point Drive
Fort Collins, Colorado 80525 U.S.A.
T: 800.446.9167
F: +1.970.221.4670
www.advanced-energy.com
Specifications are subject to change without notice.
Advanced Energy®, Ascent®, and Pinnacle® are U.S. trademarks of Advanced Energy Industries, Inc.
ENG-PulsingOptimization-260-01 0M 10.13
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