Controlling the Power Supply Shut Down and Turn On for Optimal Arc Management Performance

1. ®
The End of Hard Arcs: Controlling the Power Supply
Shut Down and Turn On for Optimal Arc Management
Performance
Skip Larson, Director Product Marketing

2. Overview
Ascent® Arc Management System™ technology provides the maximum level of
response control to manage plasma disturbances caused by charge build-ups
(arcs) in the process
•
•
The only DC sputtering supply that reduces the probability of recurrent arc events
without proactive pulsing
Fast V detection and shut down, configurable I detection, managed recovery
Four levels of
response available:
• Two factory default
• Two user
configurable
V, I, or VxI
arc detection
V
Current Threshold™ limit for
optimized recovery—AE
technology advantage!
I
Controlled power recovery
reduces probability of repeated
arcs—
the end of hard arcs

3. Standard Arc-Response Industry Practice
Problem: No Two Arcs are Exactly Alike
Fixed-time response: a ―guess‖ at the best time to shut down
Two fixed levels of control prevail in the industry:
•
•
Micro-arc (µArc) shut-down times
Hard-arc (hArc) shut-down times
These ―standard‖ responses are often good enough.
However, current decay times during an arc event differ depending on
when they happen, where they occur, and how often they occur.
Since arcs are dynamic, with no two exactly alike, some customers will
want to take advantage of AE’s proprietary Current Threshold™ limit arc
management technology

4. Arc Current Decay Distribution
Ascent 60k AZO Sm Grain Arc Characteristic
Rate of current fall as arc ends
Power to 20000 watts
40
Mean= 23.4743
Median= 22.2977
StDev= 8.8715
35
30
Count
25
20
15
10
5
0
0
Faster
10
20
30
40
50
Rate of current fall - A/usec
60
70
Slower
DC sputtering using industry-standard, small-grain AZO target

5. Arc Current Decay Distribution
Ascent 60k AZO Lg Grain Arc Characteristic
Rate of current fall as arc ends
Power = 20000 watts
60
Mean= 14.419
Median= 13.1763
StDev= 6.7865
50
Count
40
30
20
10
0
0
Faster
10
20
30
40
50
Rate of current fall - A/usec
60
70
Slower
DC sputtering using non-standard, large-grain AZO target

6. Arc Current Decay Distribution
Ascent 60k Aluminum Arc Characteristic
Rate of current fall as arc ends
Power = 50000 watts
5
Mean= 67.7006
Median= 72.5455
StDev= 17.7038
4.5
4
3.5
Count
3
2.5
2
1.5
1
0.5
0
0
Faster
20
40
60
80
Rate of current fall - A/usec
DC sputtering using industry-standard aluminum
100
Slower

7. Experimental Distribution of Arc Shut Down
Ascent 60k AZO Sm Grain Arc Characteristic
Rate of current fall as arc ends
Power to 20000 watts
Ascent 60k AZO Lg Grain Arc Characteristic
Rate of current fall as arc ends
Power = 20000 watts
40
Ascent 60k Aluminum Arc Characteristic
Rate of current fall as arc ends
Power = 50000 watts
60
Mean= 23.4743
Median= 22.2977
StDev= 8.8715
35
5
Mean= 14.419
Median= 13.1763
StDev= 6.7865
50
Mean= 67.7006
Median= 72.5455
StDev= 17.7038
4.5
4
30
25
20
Count
3
Count
Count
3.5
40
30
2.5
2
15
20
1.5
10
1
10
5
0
0.5
0
10
20
30
40
50
Rate of current fall - A/usec
60
70
0
0
10
20
30
40
50
Rate of current fall - A/usec
60
70
0
0
20
40
60
80
Rate of current fall - A/usec
All arcs are NOT the same – decay rates from 2 to 95 A/µs
•
•
•
A single arc shut down time (too short) can result in additional arc events
A single arc shut down time (too long) can result in reduced deposition rate
Material differences lead to different arc decay rates
The most advanced power supplies can automatically adjust the arc response
to match the current decay rates.
100

8. Graphical Representation of Various Current Decay
Rates
V, I, or VxI
arc detection
V
I
Current
decay range
Current Threshold™ limit for recovery—
AE technology advantage!

9. Optional Current Threshold™ Response Zoom
1) Arc Event triggered and
current spike occurs
3) Power supply re-applies power and dampens recovery
response to avoid creating another arc
4) Sputtering
continues after
controlled ramp
2) Current falls below a configurable
threshold – did not have to go to 0

10. Comparison of a Fixed-Time and a Current Threshold™ Arc
Response
Standard fixed time with
controlled ramp recovery
New technology: Current Threshold
recovery with controlled ramp

11. Arc Persistence
Less control on release after arc leads to additional, uncontrollable
heavy arcing (seen on power supplies with unregulated turn on)
Controlled recovery with Ascent power supply reduces probability of
persistent arcs
•
No Hard Arcs
Un-regulated
Hard Arc
Ascent ®
No
Hard
Arcs
Small-grain target; Leoni cable

12. Summary—Eliminate Persistent Hard Arcs
• Use of the Current Threshold functionality for arc response allows the power supply
to customize the shut-down time for the power supply to suppress an arc
Benefits of Current Threshold™ Shut-Down Response
•
More time spent sputtering: NO HARD ARCS
Benefits of Ascent® Power Supply
•
•
•
•
•
Persistent arc events are systematically addressed by (up to a total of 4) response
profiles in the Ascent power supply.
Controlled re-application of power after shut down reduces the probability of
macro-particulate-generating hard arcs.
Voltage and/or current detection for managing an arc event = a fast response.
Fast V shut down of power supply with patented low-stored energy architecture
minimizes arc energy delivered from power supply during an arc suppression
event.
Current Threshold power recovery automatically tailors the shut-down time to only
what is required to extinguish the arc.

13. AE World Headquarters
1625 Sharp Point Drive
Fort Collins, CO 80525
800.446.9167
970.221.4670
sales.support@aei.com
www.advanced-energy.com
© 2014 Advanced Energy Industries, Inc. All rights reserved.