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David Christie, PhD

David Christie received his PhD from Colorado State University and is currently director, applications technology, at Advanced Energy. He has more than 35 thin-film-related publications and six related patents.

For more information, contact  dave.christie@aei.com

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Live from GPD Finland: Glass Performance Days 2015*
June 23, 2015

This week, I’m at GPD (Glass Performance Days) Finland, a conference held every two years, on odd-numbered years, in the city of Tampere. This location has historic significance as well as intrinsic appeal. Tampere has deep history, as well as a legacy of industrial and technological vision and innovation, set in the unique beauty of the city through which the Tammerkoski Rapids flow. These rapids were harnessed to provide power to run mills in the early industrial development of the city.

The conference program includes presentations from industry leaders, corporate and government research and development laboratories, and manufacturers of components and systems—all with a focus on applications of glass to architecture and transportation.

I will give a talk about our pulsed dual magnetron sputtering (DMS) solutions, which improve cost of ownership and productivity with increased control and process monitoring capabilities. One of the points of the paper we wrote for the conference proceedings is the importance of our modular approach to the system designer and end user.

For the system designer, modularity is important, since it provides scalability with granularity. Modularity for pulsed-DC supplies for DMS can be implemented in two areas: in the DC power section and the pulsing section.

The DC power source is implemented as a standalone module. When more power is required, these power sources can be connected together in a master-slave (M/S) configuration to provide the power required for the magnetron pair.

The pulsing modules are also implemented as standalone modules with M/S capability. They can be combined to provide the pulsed power required. This modular approach, with power granularity, enables the user to purchase only the power required, and also allows power to be increased in the future simply by adding modules. Power systems can be implemented with powers from 30 to 180 kW, with granularity as small as 10 kW.

The DC supplies and pulsing modules are rack mountable, providing tremendous system design, aesthetic, and packaging flexibility. The figure below shows the DMS pulsing module, manufactured by Advanced Energy®. With the common exciter (CEX) function, power systems driving adjacent magnetron pairs can be synchronized to prevent crosstalk. Arc response also can be coordinated with adjacent pairs with additional arc synchronization functionality.

Advanced Energy DMS pulsing module for driving DMS systems














Advanced Energy® DMS pulsing module for driving DMS systems

Modularity provides new options for coating system maintenance. Typical power supplies used in large-area coating systems are rated at 100 kW and higher. These typical supplies are too large to ship to a service center for maintenance or repair, and often too complex for the end user to repair. When repair or maintenance is required, it can take time for a service person to arrive at the factory. Now, modular power system components, like the one shown above, can easily be removed and replaced with spares by the user. Units requiring maintenance and repair are small enough to be shipped easily to a service center, which enables the maintenance group in the factory to self-support with respect to power supply maintenance.

For more information, I invite you to look at our DMS product page.


Dave Christie
Director, Applications Technology
dave.christie@aei.com


*This content refers to AE-proprietary technology.




Dual Magnetron Sputtering: Delivering High Power*
June 17, 2015

Current source supplies are ideal for pulsed dual magnetron sputtering (DMS). They have the advantage of little to no current rise when an arc occurs, and they enable arc detection by voltage fall due to high incremental impedance.

Process stability is another advantage. The system tends to be self-stabilizing during the pulse; a sudden decrease in plasma impedance causes power to decrease, which tends to return the plasma impedance to its initial value. Current sources add naturally in parallel, enabling combination of units to achieve higher delivered power, with master/slave (M/S) mode operation.

The figure below is a block diagram of a current-fed pulsed power supply with voltage limiting. A current source feeds the plasma, so the plasma determines its discharge voltage; the result is increased plasma stability compared to a voltage source approach.

The switch controls the power to the plasma. The switch is opened to initiate current flow to the plasma, and closed to end the flow of current to the plasma. A voltage limiter clamps the peak voltage of the output. Notably, the voltage limiter only consumes, or sinks, current. It does not source power or provide any current to the load. A current source will try to provide whatever voltage is required to make the current flow. This is beneficial at the beginning of the pulse, where the cabling inductance and also the equivalent inductance from the electron current in the magnetron racetrack must be overcome to establish the full desired current level in the pulse. In this transition period, the plasma process cannot accept the full current from the current source. If the current source tries to provide too high a voltage, damage to the sputtering magnetron, cables, connectors, or power supply could occur. That is why it is necessary to limit the voltage with a circuit to “catch” the current until the plasma process is able to accept the full current; that is the role of the voltage limiter.

Current-fed pulsed power supply with voltage limiting connected to plasma chamber
Current-fed pulsed power supply with voltage limiting connected to plasma chamber


In a future post, I’ll explain in more detail how this circuit works to drive the plasma through realistic industrial cables.

Dave Christie
Director, Applications Technology
dave.christie@aei.com


*This content refers to AE-proprietary technology.


Hidden in Plain Sight: Bringing Thin Films to Light
April 8, 2015

Tablet and Computer Display Thin films are everywhere, but most people aren’t even aware they exist.

This is the technology behind every cell phone, touch screen, laptop, and tablet. We carry thin films in our pockets and purses, and we sit in front of them at our desks. At this moment, these words and images are visible because of thin film technology.

But still, for those of us who work in the field thin film technologies, it can be a challenge to explain exactly what thin films are and how they are used.

Cell Phone
We can hold up a cell phone and say that it is made of many remarkably thin layers of material. We can explain that such layers can have amazing properties: impervious to oxygen, conductive yet transparent, catalytic, self-cleaning, anti-reflective. They can generate electricity from light, or reflect heat while transmitting visible light.





But ultimately, as they say, a picture is worth a thousand words. It’s hard to grasp exactly how thin films work without actually seeing it illustrated. We hope the graphics below will ease those challenging conversations and promote understanding of a technology that surrounds us—sometimes literally.

Thin Film Layers Inside a Cell Phone






Inside a cell phone, each layer has specific properties
and a specific function. (Click graphic to enlarge.)














Flat-Screen Display Thin Film Layers
 
Display
Flat-screen displays are made of thousands of rows 
of tiny thin-film transistors. (Click graphic to enlarge.)











Glass Thin Film LayersArchitectural Glass
Architectural glass reflects heat while transmitting visible light. This reduces the energy consumed for air conditioning and lighting inside an office or residence.










Enter AE's #HiddenInPlainSightContest!
Enter AE's #HiddenInPlainSightContest
on Twitter!
 
AE provides power for the vacuum coating processes that create the thin films we use every day.

To celebrate the marvel of this technology, and in anticipation of SVC TechCon on April 25 to 30, we are giving away an iPad mini™ in our #HiddenInPlainSightContest. Contest details.

We’d love to see a photo of the ways you interact with thin films every day!

Click graphic for contest details..

 




Happy New Year!
December 31, 2014

Another year has gone by; 2014 is behind us now. A lot has happened in 2014. For Advanced Energy, it has been a big year. In the thin-film world; we’ve seen a lot of interest and adoption our new Ascent AMS and DMS technology for large-area sputtering. What we’ve offered is more information and control over the process than is possible with the incumbent solutions, and the large-area community has noticed. I’ve had the opportunity to talk about this exciting new technology around the world this year, and it has been received with great interest. People are always looking for a better way, and a way to implement some of the innovations they’ve been contemplating. Process engineers and coater operators like the flexibility and control to try new things, and optimize thin film and process performance. We’ve also seen growing global interest in our Solvix products for cathodic arc processes. Arc-based physical vapor deposition (PVD) is used to coat consumer, industrial, automotive, and medical products with high-performance functional coatings. Solvix solutions for arc and bias have been enabling coating developers to push the envelope and deposit even higher performance coatings demanded by the marketplace.

Now, for 2015: Happy New Year!

Dave Christie
Director, Applications Technology
dave.christie@aei.com



Delivering High Power: The Role of the Cable
December 3, 2014

In the last post I wrote about the importance of the waveform in delivering high average power from pulsed power supplies to industrial Dual Magnetron Sputtering (DMS) systems. Low inductance output cabling is preferred to fully access the performance potential of these pulsed power supplies. Preferred cable styles include tri-axial, twisted pair and other low inductance designs. However, there is one in particular that has been effective in the field. It is a four conductor cable, with two opposing conductors connected to one magnetron, and the other two conductors connected to the other magnetron. A cross section of this configuration is shown in the figure below. Litz wire is the best conductor choice for high currents. An alternative is to use a number of coaxial cables in parallel. This approach is scalable to very high currents and very low inductances and has the added advantage that appropriate coaxial cable is typically available off the shelf from multiple vendors. Advanced Energy’s Ascent DMS accessory for pulsed DMS can be mounted next to the coating chamber, separate from the DC power supply that feeds it. In that case, long and expensive AC cables may not be necessary. So, the preferred approach that gives best power delivery results can be an installation in which DC supplies are installed in the rack and the accessory (Ascent DMS) is mounted on or near the chamber itself, therefore shortening the AC cables significantly and minimizing the cable parasitic parameters.


Quadrupole output cable configuration.

Dave Christie
Director, Applications Technology
dave.christie@aei.com



Delivering High Power: The Role of the Pulse Waveform
November 11, 2014

High power industrial processes present some unique challenges to equipment designers, facility designers, and power electronics engineers. Large machines may have dimensions of tens, or even hundreds, of meters. They are typically situated in buildings with large highbays and bridge cranes overhead. Access for forklifts and other vehicles is provided in “keep clear” zones around the perimeter of the machine. An outcome that can be surprising is the location of the power supplies for the plasma processes. They can be located across the “keep clear” zones, with cable lengths of 30 m or more. This cable length, with typical inductance for realistic cables, provides a challenge for power delivery. This becomes really critical once the power exceeds 30 kW to 40 kW. As we developed the architecture for our Ascent DMS product, we addressed specifically this issue.

The waveform produced by the Ascent DMS was designed intentionally to overcome the challenge of delivering high power through an industrially realistic cable, considering length and inductance. The waveform, shown in the figure below, has an initial voltage boost segment, or pulse. The effect of the boost pulse is to create fast current rise, to effectively approximate a current square wave. This enables delivery of high powers required for industrial dual magnetron sputtering (DMS) processes, often in the range of 100 kW to 150 kW, or even higher. The effectiveness of our approach was first proven in our own industrial-grade dual magnetron sputtering system, followed by tens of field installations globally. You can learn more about the Ascent DMS here.



Dave Christie
Director, Applications Technology
dave.christie@aei.com



Live from AIMCAL USA 2014: Association of International Metallizers, Converters, and Laminators
October 22, 2014

This week I’m at the AIMCAL 2014 conference in South Carolina. The conference program includes presentations from industry leaders, corporate and government research and development laboratories, and manufacturers of components and systems. The focus of this conference is processing rolls of material, typically plastics, to radically increase their value. Inside the processing machine, the plastic moves from the supply roll to the take-up roll. The technology is referred to as roll-to-roll, or web processing. As a company, we are focused on the vacuum coating portion of the conference this week, and particularly on the plasma processing part of the vacuum coating section. I gave a talk yesterday about our new solutions for dual magnetron sputtering (DMS). The roll-to-roll community has ever-growing interest in coatings applied by DMS. These coatings are used for solar control in architectural and automotive glazing, touch screens, flexible displays, transparent electromagnetic shielding, and more.

My talk focused on ways to improve productivity and reduce cost of ownership by providing more control to the user over what happens in the process. Improved product yield, increased deposition efficiency, and reduced waste all contribute to lower overall cost of ownership and greater profitability. That’s what enables roll-to-roll processors to thrive.

You can learn more about our solutions for DMS at our DMS page here.

Dave Christie
Director, Applications Technology
dave.christie@aei.com




Magnetron Arcing: Considerations for Large-Area Coating
October 7, 2014

Large-area magnetron sputtering processes operate at high powers up to 100 kW to 200 kW, or even higher in some rare cases. Power supplies capable of delivering these high powers have considerable arc energies and deliver considerable peak currents to process arcs. It could be expected that a single arc has locally similar conditions, such as magnetic field, target surface temperature, and process gas pressure—as is true for low power (1 kW to 10 kW) processes. However, available energy that could be delivered to an arc may be ten or more times higher. The expected result is larger target material particles (macro-particles) generated by the arc as arc energies increase, as shown in Figure 1. This suggests that for large-area coating, the importance of minimizing arc energy is greatly increased.

Ironically, the local conditions for an arc, such as surface material and condition, gas species and pressures, and magnetic field, are very similar as processes scale from low to very high power. What changes is the amount of energy a power supply can deliver to an arc. Higher power supplies generally have higher arc energy. So, as magnetron sizes are scaled up for critical large-area processes, such as flat panel display, minimizing arc energy becomes critical for film quality and production yield.
The generation of macro-particles by sputtering magnetron arcing has been studied by several researchers [1-5]. Based on published data, macro-particles as large as 10 µm or larger could be expected. The details are difficult to quantify by analysis but would seem to be clearly dependent on process conditions, target material, and the details of the magnetron design, as well as power supply arc handling.

Large-area coating presents special challenges for arc energy and arc rate. The expected general trend of macro-particle size distribution and quantity scaling is shown in Figure 2. Arc energy should be reduced to minimize arc-induced macro-particle size. Arc frequency (rate) should be reduced to minimize arc-induced macro-particle quantity. Appropriate choice and setup of power supplies can minimize arc energy and arc frequency. Macro-particles generated by arcing can be included in the layer stack, as shown in Figure 3, resulting in layer system defects and a possible reduction of field reliability, characterized by premature degradation of appearance and/or reduction in performance. Macro-particles generated by target arcing can be included in the thin film layer stack, resulting in defects and possible reduction of field reliability. It is important to note that macro-particles can be larger than the film thickness. Shadowing of the adatom flux to the surface can result in voiding around the macro-particle, providing an undesired entry point for contaminants that can degrade the film over time, shortening its useful life. Therefore, it is desirable to minimize macro-particle size and quantity.

Power supply selection and setup are critical.  More information on AE power supplies for sputtering is available here.

Figure 1. Expected trend of macro-particle size with arc energy.
Figure 2. Expected trend of macro-particle size distribution and quantity with arc energy and frequency (rate).
Figure 3. Macro-particles generated by target arcing can be included in the thin film layer stack, resulting in defects and possible reduction of field reliability.

Dave Christie
Director, Applications Technology
dave.christie@aei.com

References
[1] B. Jüttner, Physica 114C, 255 (1982).
[2] C.E. Wickersham, Jr., J.E. Poole, J.S. Fan, L. Zhu, JVST A 19(6), 2741 (2001).
[3] C.E. Wickersham, Jr., J.E. Poole, A. Leybovich, L. Zhu, JVST A 19(6), 2767 (2001).
[4] C.E. Wickersham, Jr., J.E. Poole, J.S. Fan, JVST A 20(3), 833 (2002).
[5] K. Koski, J. Hölsä, P. Juliet, Surface and Coatings Tech. 115, 163 (1999).



Live from PSE 2014: 14th International Conference on Plasma Surface Engineering
September 16, 2014

This week I’m at the 14th International Conference on Plasma Surface Engineering (PSE 2014). This conference is held every two years in Garmisch-Partenkirchen, at the foot of the Zugspitze, Germany’s highest mountain peak. This conference attracts many leading researchers and innovators from around the world, all applying plasma technology to change properties of surfaces.

The conference program includes presentations from industry leaders, corporate and government research and development laboratories, and manufacturers of components and systems. The one thing the presentations have in common is plasma, used to modify surface properties in some way. This could include applying a thin-film coating to the surface or etching part of the surface away. It is also possible to modify the bond structure at the surface to make it hydrophilic or hydrophobic.

So the presentations have plasma in common. And plasmas have one thing in common: power. They need a source of power, typically electrical. That’s where AE comes in. AE manufactures precision power supplies to drive most plasma surface modification processes. There are RF and DC supplies for driving the plasma itself, power controller modules (PCMs) for driving heating elements included in many systems, and high-voltage power supplies for a variety of uses. You can learn more about our Precision PowerTM solutions here.

Dave Christie
Director, Applications Technology
dave.christie@aei.com




Magnetron Arcing: Hints from the Past?
September 2, 2014

In the magnetron sputtering process, the desired glow discharge mode is sustained by secondary emission of electrons induced by ion impact at the target surface—as an individual process. “An individual process” means that one ion incident on the surface results in emission of some number of secondary electrons (the ion impact being primary) with some probability. These secondary electrons perform bulk ionization of process gas neutrals by electron impact [1] and possibly sequential secondary processes such as Penning ionization and multiple body collisions. The undesired cathodic arc discharge mode is sustained by explosive emission of ions and electrons from small craters on the target surface in what could be considered a collective process [2]. It is a collective process because the current flowing in the arc provides heat to the arc spot, which, in turn, causes melting and explosive emission of a “collection” of target material atoms. In the cathodic arc mode, target material macro-particles are also explosively emitted from arc craters, often landing on the substrate, resulting in product yield issues.

Electrical discharge devices with the ability to operate in arc and glow regimes have been studied for some time now. Early work on the transition from the glow to the cathodic arc mode showed the importance of oxide on the target surface for sustaining an arc [3-7]. When ultra-pure noble gases were used, it was essentially impossible to sustain an arc. In some experiments, the argon gas was purified in situ with the arc operating. When a high level of purity was attained, the arc mode discharge ceased and only a glow discharge was possible. This result was attributed to formation of oxides on the surface. When the gas was purified, the oxides were eventually removed by the arc. The motivation for this work was likely to understand how to make arc sources work better. Now we are interested in keeping sputtering processes out of the arc regime. This early work at least suggests the importance of process gas and target material purity in metal sputtering processes, and perhaps sets the expectation that target arcing could develop when reactively sputtering oxides. The challenge for power supply developers continues to be innovation in arc detection and arc response to minimize arc energy and, ideally, arc rate.

References
[1] M. A. Lieberman, A. J. Lichtenberg, Principles of Plasma Discharges and Materials Processing, Wiley, New York, 1994.
[2] Cathodic Arcs, A. Anders, p. 77 - 79, Springer, New York, 2008.
[3] G. M. Schrum, H. G. Wiest, “Experiments with short arcs,” Electrical Engineering 50, p. 827, 1931.
[4] G. E. Doan, J. L. Myer, “Arc discharge not obtained in pure argon gas,” Phys. Rev. 40, p. 36, 1932.
[5] G. E. Doan, A. M. Thorne, “Arcs in inert gases. II,” Phys. Rev. 46, p. 49, 1934.
[6] M. J. Druyvesteyn, “Electron emission of the cathode of an arc,” Nature, p. 580, 1 April 1936.
[7] C. G. Suits, J. P. Hocker, “Role of oxidation in arc cathodes,” Phys. Rev. 53, p. 670, 1938.

Dave Christie
Director, Applications Technology
dave.christie@aei.com




SEMICON® West 2014: Powered by AE
August 19, 2014

I hope you all are enjoying your summer, or winter, depending on your hemisphere.

Did you know Advanced Energy Industries, Inc. (AE) of Fort Collins has a role in manufacturing large-volume consumer products? If you’re reading this article, you probably own something that was manufactured using AE products. “What would that be?” you ask. Smart phones, tablets, laptops, large-screen televisions, to name a few high-profile products. AE makes critical subsystems that power processes in the manufacture of flat panel displays, touch screen displays, memory chips, computer processor chips, and hard drives. They are used to deposit very thin coatings of material, and also to remove it in specific patterns (etching) to form electronic devices and circuits on the chips.

The thin films deposited and patterned with AE power subsystems are doubly invisible to us as consumers. They are so thin that we can’t see them as discreet coatings with our eyes, even when they’re part of the display or television screen we’re viewing. Some are also deeply hidden in a package inside of the products we use. But, even though they’re invisible, these thin films bring our favorite electronic products to life.

SEMICON® West 2014 is arguably the leading and most visible semiconductor industry event. This year it was July 8 – 10, at the Moscone Center in San Francisco. AE has been involved in the semiconductor industry during the past three decades. As the industry has evolved, AE has responded with the power technology required to drive ever more demanding etch, plasma-enhanced chemical vapor deposition (PECVD) , and physical vapor deposition (PVD) processes. AE innovations have been in the vein of precision power: generation, delivery, measurement, and control. The constant drive to smaller dimensions has driven the need for pulsing in order to provide more control of the electron energy distribution function (EEDF) in the plasma. The plasma, in turn, allows greater influence on the chemistry of etch processes, for example, since the cracking pattern of the precursor gases is a function of the EEDF. Pulsing a single RF generator is a challenge, but, for today’s and future systems, the challenge is even greater: synchronizing pulsing of multiple RF generators, and measuring power parameters of the pulsed waveforms, to allow precise control and reproducibility. This is AE’s role: powering innovation in technology from which we can all benefit and enjoy.

To learn more, check out our line of RF products.

Dave Christie
Director, Applications Technology
dave.christie@aei.com




Live from ICCG10: The International Conference on Coatings on Glass and Plastics
June 24, 2014


Advanced Energy® DMS pulsing module for driving DMS systems
This week I’m at the 10th International Conference on Coatings on Glass and Plastics (ICCG10), in Dresden, Germany. This conference is held every two years at various locations in Europe. The locations usually have historic significance as well as intrinsic appeal, and Dresden is no exception with deep history and a legacy of scientific and technical vision and innovation set in the unique beauty of the city through which the peaceful Elbe River winds.

The conference program includes presentations from industry leaders, corporate and government research and development laboratories, and manufacturers of components and systems. I will be giving a talk about our pulsed dual magnetron sputtering (DMS) solutions to improve cost of ownership and productivity with increased control and process monitoring capabilities. One of the points of the paper we wrote for the conference proceedings is the importance of our modular approach to the system designer and end user.

For the system designer, modularity is important, since it provides scalability, with granularity. Modularity for pulsed-DC supplies for DMS can be implemented in two areas: in the DC power section and the pulsing section. The DC power source is implemented as a standalone module. When more power is required, these power sources can be connected together in a master-slave (M/S) configuration to provide the power required for the magnetron pair. The pulsing modules are also implemented as standalone modules with M/S capability. They can be combined to provide the pulsed power required. This modular approach, with power granularity, enables the user to purchase only the power required, and also allows power to be increased in the future by simply adding modules. Power systems can be implemented with powers from 30 kW to 180 kW, with granularity as small as 10 kW. The DC supplies and pulsing modules are rack-mountable, providing tremendous system design, aesthetic, and packaging flexibility. The figure below shows the DMS pulsing module, manufactured by Advanced Energy. Power systems driving adjacent magnetron pairs can be synchronized to prevent crosstalk by using the common exciter (CEX) function. Arc response can also be coordinated with adjacent pairs with additional arc synchronization functionality.

Modularity provides new options for coating system maintenance. Typical power supplies used in large-area coating systems are rated at 100 kW and higher. These typical supplies are too large to ship to a service center for maintenance or repair, and often too complex for the end user to repair. When repair or maintenance is required, it can take time for a service person to arrive at the factory. Now, modular power system components, like the one shown above, can easily be removed and replaced with a spare by the user. Units requiring maintenance and repair are small enough to be easily shipped to a service center, which enables the maintenance group in the factory to self-support with respect to power supply maintenance.

For more information, I invite you to look at our DMS page here.

Dave Christie
Director, Applications Technology
dave.christie@aei.com




Dual Magnetron Sputtering (DMS): The Basics
June 11, 2014

Magnetron sputtering systems are used to deposit complex layer systems on solid substrates and flexible webs for various uses, including display, flexible electronics, packaging, lighting, decorative, architectural, and automotive applications. Some of the layers are compounds, which may be dielectrics or transparent conductive oxides (TCOs). These layers may be deposited by reactive sputtering. Dual magnetron sputtering (DMS) has been widely used for reactive deposition in inline and roll-to-roll coaters. In DMS, the magnetrons alternate roles as cathode and anode, depending on the polarity of the power supply output. DMS eliminates the need for explicit, separate anodes. This is one of its main advantages, since explicit anodes require regular maintenance and are a source of unwanted particle generation. In dielectric deposition processes, explicit anodes can stop working when they become covered with insulating material, the so-called disappearing anode effect. Magnetrons can be planar or rotatable. Now, it is common to use a pair of rotatable magnetrons for reactive DMS; an example of an industrial-scale dual rotatable magnetron system is shown in the picture below. These processes and approaches seem straightforward. It is the subtle variables that make them challenging for industrial applications, where the process must run continually day after day. Uneven target consumption can be a significant issue for DMS systems. The cause can be imbalances in power and reactive sputtering working point between the two magnetrons.


Industrial-scale dual magnetron system for large-area glass coating

In the reactive DMS process, material is sputtered from the surface of the target and travels to the surface of the substrate. The reactive gas combines with the target material at the surface of the substrate to form the compound. The difficulty comes from another surface reaction. The reactive gas also reacts with the surface of the target (it is, in fact, sub-planted into the target surface), forming a compound at and slightly below the surface. When a small fraction of the target is covered with compound, it is said to be in the metallic mode. When a large fraction of the target is covered with compound, it is said to be in the poisoned mode or fully reactive mode. The compound typically has a lower sputtering yield than the target material, so deposition rate is reduced. In some cases, the sputtering yield for the compound is only 10% of the sputtering yield for the pure target material. There is an intermediate operating point, called the transition mode. It is between the metallic and poisoned modes. In the transition mode, it is possible to deposit films with high optical quality at high deposition rates. A feedback control system is required to maintain operation in the transition mode, with voltage, reactive gas partial pressure, or optical emission used for feedback [1]. Consequently, many reactive sputtering processes are operated in the fully reactive mode, where lower rate is accepted in return for film quality and simpler control.

Dave Christie
Director, Applications Technology
dave.christie@aei.com


References
[1] W.D. Sproul, D.J. Christie, D.C. Carter, Thin Solid Films, Vol. 491 Issue 1-2 (2005) 1.



Reducing Total Cost of Ownership (CoO): Balancing Target Consumption
May 20, 2014

Large-area glass coating lines are expected to perform long process campaigns between maintenance cycles. They need to operate day after day, without issues. Long-term process operation has some important requirements. First, it is necessary to have enough material, or inventory, on the targets. Second, the target material must be used effectively—and efficiently. Efficient use requires even consumption between the two targets in the pair, such that the two targets are consumed at the same rate.

It is possible to balance target consumption in reactive dual magnetron sputtering (DMS) processes. Two things are necessary. The power supply needs to enable the control of the reactive sputtering working point of each magnetron in the pair, so each can be at the same working point. The power supply needs to control power delivered to each of the two magnetrons, so each operates at the same power.

The working point of a reactive sputtering process determines the reactive gas partial pressure, and the fraction of target and chamber surfaces covered with reactive compound. The target coverage fraction is a key parameter in determining deposition rate. In many reactive sputtering processes, voltage is a good indicator of target surface coverage fraction. As an example, the control curves of each magnetron in a pair are shown in the figure below.



For some values of oxygen flow, there are three possible voltages for each magnetron, so, when flow is used for feedback, there can be uncertainty in the actual operating point on the curve. In contrast, for each individual magnetron, there is only a single value of oxygen flow for each voltage, so using voltage for feedback allows access to the entire curve. The voltage shown in the figure is the quasi-DC sputtering voltage of the magnetron, after the transients associated with switching polarities are over. Each magnetron has its own control curve, and the curves are different, if only slightly. The differences in the control curves are unavoidable due to asymmetries that may include magnetic field strength and profile, target composition, gas flow, local pressure, or target material thickness. The result is that the magnetrons may operate at different working points, with different coverage fractions, and therefore with different voltages. And, if the voltages are different, there will also be different target material removal rates, which will result in unbalanced target consumption. One target will therefore reach end of life before the other, which may unnecessarily end the production campaign.

The most advantageous solution would be to match the power to each magnetron, and also the voltage. With two parameters to control—power and voltage—it is necessary to have two control inputs. The pulsed power supply can sense and control power balance between the two magnetrons. Voltage can be influenced by changing relative reactive gas flow to each magnetron with an auxiliary manifold and gas flow controller, using the voltage measurement provided by the power supply. If the magnetrons are rotatable, then it may be possible to influence voltage by the rotation speed of the magnetrons. The control curve moves to the left when rotation speed is increased, as shown in the figure [1].


Dave Christie
Director, Applications Technology
dave.christie@aei.com

References
[1] Reactive Sputter Deposition, edited by Diederik Depla and Stijn Mahieu, p. 191, Springer, 2008




Live From SVC TechCon 2014: A Spirit of Nostalgia and Innovation
May 6, 2014

Today we're at the 57th annual SVC TechCon 2014 conference in Chicago, one of the premier vacuum coating events in North America. It's the closest place you can come to a literal think tank. It exudes innovation. As a long-time exhibitor, we sense both the spirit of nostalgia and the anticipation around the advancements made over the last year.

Our next-generation advanced power conversion and control solutions will be on display, with the Ascent DMS product as the centerpiece. AE was the first to introduce regulated pulsing to the market in the early 1990s for newly developed reactive sputtering processes, and the DMS product is a part of our broad portfolio of pulsing products to enable the next wave of innovation. Our newest DC and RF power conversion systems offer advanced integrated pulsing options—including controlled voltage reversal, standard pulsing, bipolar pulsing, bias pulsing and arc pulsing, as well as synchronized pulsing between bias and arc sources. With AE’s controlled, precise, shaped power delivery, process engineers can tailor surface properties while maintaining high deposition rates more efficiently.

The unique features of the Ascent DMS series include repeatable, tunable film parameters and lower cost of ownership in large-area glass and other industrial, dual magnetron sputtering applications. Designed to deliver 30 to 180 kW of bipolar power—with independent power control to each cathode—Ascent DMS units permit process engineers to customize duty cycle to the wear profile of each target. This enables increased target-erosion uniformity and full utilization of each cathode for longer campaigns. A controllable pulse rise feature offers significant advantages for producing more uniform and higher density films, while unique power-delivery options include selectable frequency, independent power-ratio regulation for each magnetron and power, current or voltage regulation..

Stop by our booth (#1100) and check out our displays, as well as some of our new apps. If you can attend one of our technical presentations, you'll learn even more. Our applications experts will be among the many presenters at the show, addressing multiple topics that range from dual magnetron sputtering to advances in tribological coatings. Details can be found on our landing page at www.advanced-energy.com/svc.

We look forward to seeing you at this year’s show!




Controlling Pulsed DMS Reactive Sputtering Processes: Getting a Solid Voltage Feedback Signal
April 22, 2014

Large-area coating is used to deposit complex layer systems on glass for architectural and automotive applications, and a myriad of others, including coatings on flexible webs. Some of the layers are compounds, which may be dielectrics, or transparent conductive oxides (TCOs). These layers are commonly deposited by reactive sputtering. Dual magnetron sputtering (DMS) is now the typical choice for reactive deposition in large-area coaters.

In the reactive DMS process, material is sputtered from the surface of the target, and travels to the surface of the glass. The reactive gas combines with the target material at the glass surface to form the compound. The difficulty comes from another surface reaction. The reactive gas also reacts with the surface of the target (It is in fact sub-planted into the target surface.), forming a compound at and slightly below the surface. When a small fraction of the target is covered with compound, it is said to be in the metallic mode. When a large fraction of the target is covered with compound, it is said to be in the poisoned mode. The compound typically has a lower sputtering yield than the target material, so deposition rate is reduced. In some cases, the sputtering yield for the compound is only 10% of the sputtering yield for the pure target material. There is an intermediate operating point, called the transition mode. It is between the metallic and poisoned modes. In the transition mode, it is possible to deposit films with high optical quality at high deposition rates. A feedback control system is required to maintain operation in the transition mode, with voltage, reactive gas partial pressure, or optical emission used for feedback.

When a reactive process is operated at constant power, it has a unique control curve with respect to oxygen and voltage, as shown in the figure below. This is an illustrative example created to explain key concepts. There is a unique value of oxygen flow for each voltage. On the other hand, there can be multiple values of voltage for some oxygen flows; there is a region where there are three possible voltages for a particular oxygen flow value. Consequently, voltage could be useful as feedback for closed-loop control, but flow would not. The top part of the curve corresponds to the metallic mode, where the film has high deposition rate. The films deposited in this region have a high metal content, with high optical absorption, and are generally not suitable as dielectric layers. The middle part is the transition region, where the deposition rate is high. Films produced here can have low optical absorption and can be quite useful as dielectric layers. The bottom part of the curve corresponds to the poisoned mode, where deposition rate is low, the process is intrinsically stable, and films produced have low optical absorption with good optical quality for use as dielectric layers.



A waveform specifically designed for driving pulsed DMS systems is shown in the figure below. Quasi-DC sputtering conditions exist in the flat portion of the waveform, after switching transients are passed. This is where voltage measurements representing the quasi-DC sputtering voltage are taken, providing a good indication of the fraction of the target surface covered with compound and the relative target consumption rates. A voltage measurement here provides a solid signal for controlling the reactive sputtering process in the transition region. The AE DMS Accessory provides this type of voltage feedback for use in controlling reactive sputtering processes.




Dave Christie
Director, Applications Technology
dave.christie@aei.com




Success is in the Details: Not-So-Obvious Subtleties of Voltage Control
April 8, 2014c
The possibility of controlling reactive sputtering processes in the transition region has been intriguing and compelling for as long as I have been in the thin-films industry (actually, since before I joined the industry in 1995). It has also been challenging, due to subtle and nuanced issues with practical details such as process arcs. When the process arcs, the system power supply needs to respond. Power supply arc response is critical for success.

I met Uwe Krause, now my colleague and fellow blogger at Advanced Energy, at the ICCG conference in Maastricht, in 2000. He had done some interesting experiments on a large-area reactive sputtering process operating in the transition mode. He’d tried various shutdown times for the power-supply arc-handling response. What he showed was that longer shutdown times could result in disruptions to the process that were much longer than just the power supply shutdown time; the evidence was the perturbation in the partial pressure of oxygen, measured with a lambda sensor [1].

I was fascinated with his results, and with the notion that I could model the effect. I discovered that Bartzsch and Frach, and also Malcomes and Vergöhl, had extended the Berg model to include dynamics as part of their work. I used their work as a guide to build a dynamical model. Now, I could model what happened when the power supply was shut off, start to understand what happens internally to the process, and see if my model predicted the results Uwe had seen empirically.

I modeled the power supply arc response, with interruptions of differing durations. I was pleased to get results that were consistent with Uwe’s empirical data and conclusions, showing that shutdowns that are too long can result in disruptions to the process much longer than the actual shutdown. In addition, I was able to get and share some intuition about just what was happening inside the process. Quantitatively. This helped me to rapidly grow my intuition about reactive sputtering, and to share that intuition with the thin-film community [2]. (Read the paper: Power System Requirements for Enhanced Mid-Frequency Process Stability.)

Similar intuition was used by the team that developed transition-mode voltage control for the Advanced Energy® Crystal® power supplies. The arc-response recovery protocol was enhanced to enable integrated voltage control to work effectively. When reapplying power after an arc occurs, a short period of higher power helps to return the target to the pre-arc condition, as shown in the figure below [3]. (Read the paper: Voltage Control for Reactive Sputtering: Improving Typical Sputter Rate while Dramatically Reducing Input Power Requirements.) More of the target becomes covered with reactive compound. Oxygen partial pressure increases, since oxygen is adsorbed on the target surface but not removed by sputtering during the shutdown. Also because target material is not sputtered during the shutdown, getter pumping at the chamber surfaces decreases. The higher power applied immediately after the arc response accelerates the return to the equilibrium target surface coverage fraction and oxygen partial pressure.

This subtle enhancement to the Crystal arc response enables success in voltage control of reactive processes worldwide, every day.



Dave Christie
Director, Applications Technology
dave.christie@aei.com

References
[1] U. Krause, et al., “Requirements for the System Power Supply Sputter Source for High Power Pulsed Magnetron Sputtering,” Proceedings of the 3rd International Conference on Coatings on Glass, p. 173, 2000.
[2] D.J. Christie, E.A. Seymour, “Power System Requirements for Enhanced Mid-Frequency Process Stability,” Society of Vacuum Coaters 46th Annual Technical Conference Proceedings, p. 257, 2003. 
[3] C. Gruber, et al., “Voltage Control for Reactive Sputtering: Improving Typical Sputter Rate while Dramatically Reducing Input Power Requirements,” Society of Vacuum Coaters 52nd Annual Technical Conference Proceedings, p. 153, 2009.



Free, Live Webinar:
Dual Magnetron Sputtering (DMS): Improving Productivity with Increased Control
March 25, 2014 | 9 A.M. MST / 11 A.M. EST

Thank you for joining us for our discussion of power solutions for dual magnetron sputtering processes.

Missed the live webinar? Please register and watch the full recording here: For more information about the AE DMS accessory, please visit:






Choosing Between DC and RF for Sputtering Applications
March 11, 2014

I get this question a lot: “How do I know when to use DC and when to use RF for a sputtering application?”

Of course, the first thing to consider is film requirements. Typically, RF makes a better thin film than DC, pulsed DC, or AC. The RF-sputtered film will be smoother and have better packing density. RF also deposits the film at about 20% of the DC rate.

If you want to sputter using DC, pulsed DC, or AC, you must have a conductive (or semi-conductive) target. I always check the conductivity of a target by placing my ohm meter probes anywhere on the target surface. I need to see less than 650 kΩ.

We used to only have analog ohm meters with a needle. A “wiggle” on the meter confirmed that we could use DC, pulsed DC, or AC. Now that we have digital meters, it’s necessary to put a value on the “wiggle.” On the digital readout, 650 kΩ seems to coincide with an analog meter “wiggle.” This is why we need to use a dopant such as Al on the Si targets for DC-sputtered SiO2 films. The dopant makes the target surface semi-conductive enough (about 400 kΩ and less) to successfully sputter with DC, pulsed DC, or AC. We can also sputter this same doped target with RF. We would need RF to sputter SiO2 from a quartz target, as its resistance reading on the target surface is infinite.

RF hasn’t commonly been used with rotatable magnetrons yet, as the end blocks tend to bind up and leak water with the 13.56 MHz RF signals. However, we are safe with DC, pulsed DC, and AC on rotatables.

For more information on determining the best type of power for your sputtering application, please consult the following resources: Good luck and be safe.

Doug Pelleymounter
Field Applications Engineer
doug.pelleymounter@aei.com



Increasing Flow to Increase Power: How Voltage Control Works
February 25, 2014

Controlling reactive sputtering processes is challenging, and there are several options. Voltage control offers a way to reliably achieve a higher deposition rate at the same power, or to consume less power at the same deposition rate, with a stable process and good film quality. The voltage controller can be integrated into the system power supply, with no special additional sensors required.

A family of control curves is shown in the figure below. Voltage control provides a way to control operation in the transition region with control integrated into the power supply. This is an illustrative example created to explain the concept. At point A, there is no oxygen flow. There is just the argon process gas flow normally used for sputtering, to achieve the desired sputtering pressure. At the selected voltage, the process operates at 20 kW. As the oxygen flow is increased, the process moves to point B, at 40 kW. When oxygen flow is increased even more, the process moves to operating point C, at 60 kW, and then to point D, at 80 kW. Finally, when oxygen flow is increased even further, point E is reached. Point E is on the 100 kW curve, so the power supply delivers 100 kW to the process. At a given flow, there is a unique point on the control curve for each voltage. And, at a given voltage, there is a unique power for each value of flow at desired transition region operating points. This enables stable control of the process operating point, by controlling voltage with the power supply, and oxygen flow with a mass flow controller. Power is monitored with the instrumentation built into the power supply, and oxygen flow is adjusted to achieve the desired power.


Illustrative example of a family of constant power control curves for a reactive sputtering process. Power increases with oxygen flow when voltage is held constant in the transition region.


Voltage control has been integrated into a power supply designed for driving DMS magnetron pairs with mid-frequency (MF) AC power. This power supply is shown in the picture below. It is capable of fast arc detection and fast shutdown, with very low arc energy and short shutdown time.

There are some key requirements for stability of reactive processes operated in the transition region. One is short shutdown time when an arc is detected. Shutdowns that are too long can result in disruptions to the process much longer than the actual shutdown. This has been studied both empirically and with numerical simulations [1], [2]. The power supply shown here has sufficiently short shutdown time for stable operation in the transition region.


Advanced Energy® Crystal® Mid-Frequency DMS supply with integrated voltage control for transition mode reactive deposition. Click for more info…


Dave Christie
Director, Applications Technology
dave.christie@aei.com

References
[1] U. Krause, et al., “Requirements for the System Power Supply Sputter Source for High Power Pulsed Magnetron Sputtering,” Proceedings of the 3rd International Conference on Coatings on Glass, p. 173, 2000.
[2] D.J. Christie, E.A. Seymour, “Power System Requirements for Enhanced Mid-Frequency Process Stability,” Society of Vacuum Coaters 46th Annual Technical Conference Proceedings, p. 257, 2003.




Innovating Cathodic Arc Deposition: High-Performance Bias
February 11, 2014


The “field” we work in (That’s why we are called “field" applications engineers.) involves an endless variety of technology and customers. Sputtering comprises a large part of this field, but cathodic arc coating is another a significant application we work with. And, yes, this application, too, is characterized by an endless number of processes and combinations of technologies and tool designs.

To give an example, in the European Union, road transport is the second biggest source of greenhouse gas emissions, right after power generation. It contributes about one-fifth of the EU's total emissions of carbon dioxide (CO2) (http://ec.europa.eu/clima/policies/transport/vehicles/cars/faq_en.htm). Under EU regulations, average CO2 emissions from cars should not exceed 130 g CO2 per kilometer by 2015, and should drop further to 95 g/km by 2020. So, car manufacturers need to find ways to decrease friction in order to save gas, as gas conservation is an effective way to reduce CO2 emissions. This could be realized several ways, one of which is using hard-coating tools to create layer stacks for increasing wear resistance and decreasing friction.

For this application, there are several ways to create plasma inside the tool, but the majority of them use a bias power supply.

Cathodic arc system

As long as the substrates are conductive, one can run the bias power supplies as DC or pulsed DC. However, non-conductive substrates require an RF supply in order to create a sufficient bias voltage. The purpose of the DC and pulsed DC bias power supply is to apply a direct voltage against ground, and depending on the process windows, to guide the ions to the substrate.

For tools performing arc evaporation, a bias is virtually mandatory. The process window of these bias power supplies is quite large. Processes run with low bias voltages, even below 50 V, on one edge of the process window, and also high voltages, up to 1000 V, on the other side. Of course, the state-of-the art power supply needs to be tapless (no tap to switch for customers at the output), with a wide impedance range.

US Patent 6,567,278
US Patent 6,567,278

So, you have to find a way to deliver a stable voltage output between, let’s say, 20 V and 1000 V. This unit must be robust and highly efficient. Last but not least, all of these parameters must be available at an acceptable price.

The figure above shows the implementation of a wide impedance range in one unit without taps in the output transformer. In fact, the unit combines the parallel (for high current) and serial (for high voltage) operation of two inverters. Built for bias operation and with many years in the field, this concept is proven through real-world performance. Read more about arc and bias power supplies for cathodic arc deposition...


Uwe Krause
Senior Applications Engineer
uwe.krause@aei.com



Controlling Reactive Sputtering Processes: Why Voltage Control?
January 28, 2014


Reactive sputtering is used for a tremendous variety of industrial coating applications. In reactive sputtering processes, sputtered material is combined with reactive gas at the surface of the substrate to form a compound. Sometimes, the compound is insulating or dielectric, even though the magnetron target is conductive. There is, however, some complexity to controlling reactive sputtering processes. A simple model was created by Berg and his colleagues at Uppsala University [1]. This model helps to explain some of the phenomenology by tracking fluxes of ions, sputtered material, and process gas.

Reactive gas is consumed by the system pump, and is getter pumped at the chamber surfaces (including the objects being coated) and the target surface. The model equates the flow of gas into the chamber with the three consumption rates. Sputtered material travels from the target to the chamber surfaces. Both intrinsic target material and compound are assumed to be sputtered from the target surface, with uniform distribution to the chamber surfaces.

The figure below shows the fluxes of reactive gas, F, sputtered intrinsic target material, FM, sputtered compound, FC, and ions, J. The figure also shows that a fraction of the target surface, Øt, and a fraction of the chamber surfaces, Øs, are covered with compound. Getter pumping at the surfaces will occur only on the uncovered fractions. It is also important to note that the coverage fractions are not necessarily equal. The compound can have a much lower sputtering yield than the intrinsic target material, so when the target coverage fraction is high, the deposition rate can be low.



An example control curve for a reactive sputtering process is shown in the figure below. This is an illustrative example that shows some of the important characteristics of a reactive sputtering process from the control perspective. You can see that each value of voltage has a unique oxygen flow. On the other hand, some values of oxygen flow correspond to three values of voltage. Voltage can be used as a process control parameter, since there is a unique process working point for any given voltage on the curve.

Metallic mode, where target coverage fraction is very low, is at the top of the curve. Films deposited in metallic mode tend to have high absorption. Poisoned mode, where target coverage fraction is high, is at the bottom of the curve. Voltage is lower in poisoned mode since the secondary electron emission coefficient is higher for the dielectric covering most of the target, so less voltage is required to achieve the same (constant) process power. Films deposited in poisoned mode tend to have high optical quality; however, the deposition rate can be very low. The middle of the curve is the transition region, where both high optical quality (with low absorption) and high deposition rate are possible. Voltage control can be used to access this region.



For more information on implementation of voltage control in large area processes, please read our post from January 14, 2014.

Dave Christie
Director, Applications Technology
dave.christie@aei.com

Reference [1] S. Berg, et al., “Modeling of Reactive Sputtering of Compound Materials,” JVST A 5(2), Mar/Apr, p. 202, 1987.



5 Easy Steps to 5X Full Oxide Rate
January 14, 2014


Process engineers understand the benefits of achieving higher deposition rates while using less incoming power.  We’ve also experienced the spiral into metal mode or full oxide mode simply by looking at the chamber the wrong way.

To achieve higher deposition rates by running “high on the transition curve,” we typically manipulate power supply voltage while in power control mode. In the case of doped silicon dioxide, we would then adjust the percent O2 in the process accordingly to keep the voltage (usually around 650 V for SiO2) where we want to run.

But this creates a pretty darned steep slope that we will slip and slide upon without costly aids such as a very fast MFC (40 msec from zero to rail) or a special PID. This also adds to the probability of a 2 A.M. call, as the full control loop must be stable and repeatable day after day.


Hysteresis curve

Here’s another way. The Advanced Energy® Crystal® AC power supply has a pretty cool built-in algorithm to run high on the curve without special MFCs or PIDs. It’s easy:
  1. Set the supply in voltage control mode.
  2. Give it a meaningful set point while in a full Ar atmosphere (such as 650 V). 
  3. Turn on the process.
  4. You will notice that the power is quite low. Add O2 until you reach the power that you desire. 
  5. Run product.
“Wow,” you say.  “How does this happen?” 

Well, the power fluctuates a few watts up and down to keep the voltage constant. As the O2 content increases, so too does the power to consume it. When the O2 content decreases, the power also decreases to keep the proper O2 percentage in the plasma. 

“OK, Doug,” you ask, “what happens if there’s an arc?” 

Of course we want the Crystal power supply to react to the arc exactly as it is famous for, so there will be no spits or bands on the substrate. The difference here is that it will revert to process power by first increasing the power to consume the excess O2 that popped into the process during the arc. This makes for a very stable and repeatable regime.

This is particularly good for web coating, as the substrate and therefore the load is constant, and really all we need to deal with is arcing. Glass coating can be accomplished in the same way if the gap between lights is small. Pieces parts can also be done if the gaps are small. 

I have experienced 4X to 5X full oxide rate with little effort. Even 8X to 9X is achievable with tweaks to gas delivery set up, process pressure (aka: Ar) control, and substrate (load) refinements.

The result will be more square feet of material into the box without 2 A.M. calls for help. 

It is worth a try. Good luck. Be safe.

For additional information, please read this reprint from the proceedings of Society of Vacuum Coaters Inc., April 2009:
Voltage Control for Reactive Sputtering: Improving Typical Sputter Rate while Dramatically Reducing Input Power Requirements

Doug Pelleymounter
Field Applications Engineer
doug.pelleymounter@aei.com



Contemplating Disruption
December 31, 2013


It’s New Year’s Eve. Another year passed, whooshing by like the Shinkansen, Japan’s venerable bullet train. The New Year is hours away, a fresh start, still crisp with potential. We celebrate the coming of the New Year, and the passing of the old. It’s a time to be with family and friends, to enjoy traditions.

There is something comforting to me about our family traditions, and reassuring: parades, our traditional New Year’s Day dinner, football games. Some people take down decorations, but we never do. It’s our tradition to leave them up for a while and let the afterglow of the season fade slowly.

Now, I’m taking time to stop and reflect about the past year, and maybe the past in general. I’m also thinking about the coming year. In the past I made New Year’s resolutions about things I wanted to stop or start doing. I don’t do that anymore—it just didn’t work for me.

This New Year’s Eve, I’m thinking about things differently. I’m grateful for many good things in my life, and for the many opportunities I’ve had in 2013. And, I’m contemplating disruption. Discontinuity, fracture, irreversible change. For the better. Change for change’s sake? No. Rather, a different way of doing things, of thinking. One thing may be enough.

What do I mean by disruptive? I mean changing the way we think about things. For example, CRTs (cathode ray tubes) are done—it’s all FPD (flat panel display) now—a disruption enabled by large-scale thin-film technology, and committed community. It’s game changing. Now we all expect high-quality flat panel displays on our smart phones. Perhaps we can all disrupt our worlds in some way.

At AE, we’re introducing a new way to think about power for dual magnetron sputtering (DMS), urging users to take back control of power parameters and get access to more information from the process. Putting more capability in the user’s hands, enabling them to disrupt the world with their new products. We have a new webinar about it; you can see it here:

Take Back Control with a Bi-Polar Pulsed DC Solution webinar.

Have a wonderful New Year's celebration!

Dave

Dave Christie
Director, Applications Technology
dave.christie@aei.com



What Drives Today’s Developments in Power?
December 17, 2013


For all of us, the need to lower production costs, the development of new process technologies, and the opening of new market segments are key drivers. This is true not only in the semiconductor industry, where increases in wafer size drive the need to lower costs and increase throughput, but also in industrial applications, such as flat panel display, glass, hard coatings, and optical coatings, where similar requirements generate technological development at a very high level.

And what does this mean for AE?

Take a look at the Ascent® product line, our high-power DC family. The Ascent AMS (Arc Management System®) series was designed for stable power delivery even through high arc conditions, such as we see in the field during AZO sputtering. Key features of this series include a dynamic control system, extremely fast arc handling, and the lowest stored energy in the industry.

Historically speaking, dual magnetron systems performing conventional bi-polar magnetron sputtering are not driven by DC power. Traditionally, even a highly dynamic DC power supply would not suit these processes. However, responding to increasing process and industry demands, AE developed the Ascent DMS dual magnetron sputtering accessory to enable the benefits of DC power in dual magnetron sputtering applications. It provides DC-like arc handling and very low arc energy, and allows the use of new cost-effective target materials, offering solutions for key market and application challenges.

For more information, please visit our Ascent DMS information page.

Uwe Krause
Senior Applications Engineer
uwe.krause@aei.com



December 3, 2013


Thin films are amazing. They can change the properties of surfaces in dramatic and wonderful ways. Maybe you are involved in the thin-film industry, as I am. Have you ever tried to describe to your friends, neighbors, family, even co-workers, what you do, or what thin films are, or what they are used for? When I add the concept of vacuum coating, it gets even more interesting. “Vacuum cleaners? So you work with vacuum cleaners?” No, not vacuum cleaners. The fact is that we in the thin-films industry do things that are invisible to most people. Invisible and secret. Important and pervasive. Very thin – in some cases, we speak of multiple monolayers or tens of monolayers. And with amazing properties. Lower friction. Impervious to oxygen. Reflect heat and transmit visible light. Conductive and transparent. Converting light to electrical power. Catalytic, self cleaning.

At Advanced Energy, we provide power to vacuum coating, etching, and cleaning processes. I’ve been in the thin-films industry, and at Advanced Energy, for over 18 years now. It’s been an amazing journey. I joined as a staff engineer focused on developing technology and products for magnetron sputtering applications. As I learned more about the field, my fascination with the applications of our products led me to pursue a PhD and research in applications. Today, I serve as director, applications technology, in our Thin Films business unit. Every year, I learn about new applications of thin films. New ways that they change the properties of surfaces. New opportunities in business resulting from ideas, research, hard work, and persistence.

At Advanced Energy, our contribution is process power. Not just raw power. Controlled, precise, shaped power. Delivered to the process. Managed power. Things happen in the process, things like arcing. The power supply has to deliver power, and respond to manage the process when things like arcs or impedance excursions happen. That is our passion. Providing power to your processes, to enable you to create the next exciting thin-film product.

Look for our next post, on December 17. Our applications team will be digging into power for thin-film processes and other interesting subjects. Until then, enjoy your journey into the holiday season.

Dave Christie
Director, Applications Technology
dave.christie@aei.com