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`Exhibit 15
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`Case 6:20-cv-00636-ADA Document 48-18 Filed 02/16/21 Page 2 of 9
`fl~ c~ ADVANCED
`L~i[L-?.1~NERGY®
`
`----- ---------------- --- -- -- _ ( ©(Q) r?JW J_ - - - - -- -- - - -- - - - - - - - - - -- - - -
`
`By Richard A. Scholl of Advanced Energy Industries, Inc.
`
`POWER SUPPLIES
`FOR PULSED PLASMA
`TECHNOLOGIES:
`STATE-OF-THE-ART
`AND OUTLOOK
`
`The power supply is important in the practice af plasma processing because of the
`intimate connection between it and the plasma. That the output circuits of even simple
`de power supplies could affect the results af plasma deposition has been known and
`investigated for over 30 years. As a better understanding of the nature af the interaction
`between the power supply and the plasma developed, the power supply design evolved from
`a simple powering element to a key element in the system. This resulted ultimately in the
`development af pulsed plasma systems.
`This paper reviews the development af the plasma power supply and its interaction with
`the plasma with particular emphasis on pulsed systems. Nonlinear effects and the effect of
`source impedance on plasma properties are discussed. The current state-of-the-art af pulsed
`power supplies is presented, including system control issues and a brief discussion of intellectual
`property status in both the United States and Europe. Indications of the directions of future
`developments in processing and pulsed power supplies are given, including the effect of availability
`of semiconducting switching devices for RF power generators as well as for de and low-frequency
`ac power supplies.
`
`INTRODUCTION
`Pulsed power is very much in vogue these days. Whenever
`conventional techniques fail to produce acceptable results,
`process engineers think of pulsing to give them a new
`dimension and increased possibility for success. This paper is
`intended to present the state-of-the-art in power supplies for
`plasma processing with particular emphasis on pulsed power
`equipment.
`
`PULSING BENEFITS
`
`Nonlinearities
`In cases where there is a nonlinear effect ( with greater
`power providing some benefit X faster than linearly), if the
`system is limited to some average power, pulsing will provide a
`higher average value for X. As an example, pulsing the bias on
`a substrate permits enhancement of bombarding ion energy
`without undue heating of the substrate. Also, properties often
`depend upon the rate of deposition, so pulsing at a high rate
`can provide desirable film properties without overheating of
`the target or other parts of a system.
`
`Time Dependencies
`If an effect happens primarily at the beginning (or end) of a
`process, pulsing can provide many beginnings (or endings) and,
`thereby, enhance the effect. For example, it has been reported
`that the energy distribution of the electrons in a plasma is quite
`broad at the beginning of a powering pulse, but redistributes to
`a Maxwellian distribution within a few tens of microseconds.
`Continued pulsing with pulses shorter than this increases the
`average energy of the electrons as well as of the population of
`species created from the higher energy electrons.
`
`Clearing Charges
`Periodic reversal of the
`voltage of an electrode can clear a
`buildup of charges by attracting the
`opposite charge during the pulse.
`This technique has been widely used to
`reduce or prevent arcing due to charge
`buildup, especially in reactive sputtering.
`
`So, for the most part, pulsing is
`done to:
`• Avoid arcing--or at least to reduce
`arc defects
`• Achieve better film properties: denser,
`tougher, brighter, more transparent
`• Achieve higher yields
`•
`Increase throughput and productivity
`
`WHAT IS PULSED POWER?
`Pulsing has been shown to do all of the above,
`but not all at the same time. There is a growing
`body of literature on the subject showing sometimes
`conflicting results and indicating that the field is still
`too new to have settled into a clear body of knowledge.
`
`A glossary of terms is given at the end of this paper,
`but here it will be useful to separately define pulsing. If a
`system is pulsed, the power may either contain a periodic
`transient followed by a return to steady state, or it may consist
`of a periodic variation between two states. In the former case,
`the transient may be self-generated or may occur in response to
`a plasma event, such as an arc. In either case, the pulse may be
`represented by a change in the level of a de voltage or current,
`
`··-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·
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`-··
`1
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`BEST AVAILABLE COPY
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`Case 6:20-cv-00636-ADA Document 48-18 Filed 02/16/21 Page 3 of 9
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`POWER SUPPLIES FOR PULSED PLASMA TECHNOLOGIES: STATE-OF-THE-ART AND OUTLOOK
`
`or by a change in the amplitude of a carrier wave. The former
`has been extensively used in the processes of plasma diffusion,
`cleaning and etching, substrate biasing, and reactive and
`nonreactive sputtering. The latter has been used, for example,
`in semiconductor etching. In principle, a pulse may also be
`represented by a shift in the frequency or phase of a carrier
`wave, but this has not been explored in plasma processing to
`my knowledge.
`
`and for times short compared to this regulation response time,
`the output impedance is determined by passive elements in the
`system. Generally, the pulse times in a pulsed system are short
`compared to the regulation response time. If the output circuit
`is dominated by a large parallel capacitor, the supply will tend to
`be a constant voltage source for short periods; if the output is a
`large series inductor, the supply will tend to look like a current
`source for the pulsing interval.
`
`PULSED DC
`This paper is principally directed to pulsed de (wherein the
`pulse is represented by a shift in voltage or current and, thus,
`power). The shift may be from one power level to another, may
`come from a power level to zero power (interruption), or may
`be a shift in voltage from one polarity to the opposite. The
`pulse may be intended to be square (in that only two levels are
`expected), or it may be a half sinusoid (which is a special case
`of amplitude modulation of a carrier wave). In practice, the
`waveforms are virtually never as intended due to nonlinearities
`of either the plasma or the power supply circuitry. So, the shapes
`of the resulting power waveforms are complex. One may not be
`able to control the power waveform, but by controlling the
`power supply output impedance, one can gain a measure of
`control over either the voltage or the current.
`
`A high-output impedance gives the power source the
`characteristics of a current source ( in that the current will tend
`to remain as programmed regardless of the impedance of-and,
`therefore, the voltage across-the plasma). A true current
`source has an infinite output impedance and (within its limits
`to produce adequate voltage) will be unaffected by the plasma
`impedance. In this case, the voltage will be completely
`determined by the plasma impedance characteristics. The power
`supply's limit in producing voltage is called voltage compUance or
`just compliance and can often cause problems in plasma
`applications.
`
`A low-output impedance gives the power source the
`characteristics of a voltage source (in that the voltage will tend
`to remain as programmed regardless of the impedance of-and,
`therefore, the current through-the plasma). A true voltage
`source has a zero output impedance and ( within its limits to
`produce adequate current) will be unaffected by the plasma
`impedance. In this case, the current will be completely
`determined by the plasma impedance characteristics. The power
`supply's compliance for current is called its current Umit, and it
`can also cause problems in plasma applications.
`
`A power supply may be current regulated ( which causes the
`output impedance to be infinite), voltage regulated (which
`causes the output impedance to be zero), or power regulated (in
`which case the impedance is not constant, but is controlled to
`be always equal to the load [plasma] impedance). The circuits
`that control the power supply have a response time, however,
`
`2
`
`TYPES OF PULSING DC POWER SUPPLIES
`
`Square-Wave Voltage-Fed Systems
`In this approach, semiconductor switches place a large
`charged capacitor across the plasma periodically. The switches
`may disconnect during the pulse, may reverse the polarity of the
`capacitor, or may switch a different capacitor across the plasma.
`The capacitor appears as a constant voltage for short periods, so
`the system appears to have near-zero output impedance. Such a
`system is commonly used for substrate biasing (in which case
`the capacitor is applied for a short time and then disconnected
`for a longer time). A simple circuit is shown in Figure 1. The
`result is a pulse of voltage on the substrate, which attracts ions
`from the vapor stream. If the stream is largely ionized, the ions
`will be strongly attracted to the substrate and arrive with high
`energy. This can greatly enhance film adhesion and affect stress
`and other film properties. During the interpulse period, there is
`no ion bombardment. The power dissipated in the substrate is
`equal to the ion current times the pulse voltage times the duty
`factor; if the last is kept small, the power may be small even
`with high voltages and currents, avoiding excessive substrate
`heating.
`
`Semiconductor
`Switch
`
`Capacitor
`
`Cathode
`
`Anode
`
`Chamber
`
`Figure 1.
`
`Voltage-fed systems are used in substrate biasing and plasma
`diffusion, but are not so effective when applied to sputtering
`applications because of difficulties with ignition, the delay time
`in building the plasma density, and, therefore, the sputtering
`rate. When the voltage source is disconnected, the plasma decays
`with a two-fold time constant-fast at first(,:== 5 µs) as the hot
`electrons leave the plasma, and more slowly later(,:"' 50 µs) as
`particles with slower velocity are lost to the chamber walls. To
`
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`POWER SUPPLIES FOR PULSED PLASMA TECHNOLOGIES: STATE-OF-THE-ART AND OUTLOOK
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`rebuild the current after this decay requires time, unless excess
`voltage is available to accelerate ionization. The buildup of
`current in such a system is shown in Figure 2.
`
`Arc-handling is more difficult in such a system because the
`arc must be detected by an increase in current, and this takes
`time to detect. During the detect time, energy is delivered to
`the arc from the primary power source.
`
`f--1tf---J
`-I TON j- roFF-I
`
`Voltage Waveform
`
`Figure 2.
`
`Current Waveform
`
`Voltage-fed systems can be used for dual targets. In this
`configuration, shown in Figure 3, four switches are used in an
`H,bridge configuration to reverse the voltage from the capacitor
`across a pair of targets. This system suffers from the same
`ignition, delay time, and arc-handling problems mentioned
`above.
`
`Square-Wave Current-Fed Systems
`In the patented111 configuration shown in Figure 4, an
`inductor is charged to a current by a switch in parallel to the
`plasma. When the switch is opened, the inductor current is
`diverted to the plasma. Since the inductor appears as a current
`source for short periods, such a configuration has a high output
`impedance. The voltage compliance is limited by the voltage
`rating of the switch and the need to provide snubbing circuits (not
`shown in Figure 4) that act to limit the voltage excursions to a safe
`level for the switch. Nevertheless, when the switch is opened into
`a partially decayed plasma, the voltage rises quickly, which
`accelerates the buildup of current. This greatly increases the power
`delivered to the plasma during the pulse. The voltage and current
`waveforms are shown in Figure 5. Systems using this approach are
`widely used for reactive sputtering; their use in this regard for
`depositing insulating films is the subject of an issued US patent:121•
`
`Inductor
`
`Semiconductor
`Switch
`
`Figure 4.
`
`Cathode
`
`Anode
`
`Chamber
`
`Current Waveform
`
`Cathode
`
`Anode
`
`Chamber
`
`Figure 3.
`
`Figure 5. Waveforms for the Current-Fed
`
`Voltage Waveform
`
`3
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`
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`Case 6:20-cv-00636-ADA Document 48-18 Filed 02/16/21 Page 5 of 9
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`POWER SUPPLIES FOR PULSED PLASMA TECHNOLOGIES: STATE-OF-THE-ART AND OUTLOOK
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`Inductor A
`
`Semiconductor
`Switch A
`
`Cathode Cathode
`
`Chamber
`
`Inductor B
`
`Semiconductor
`Switch B
`
`Figure 6.
`
`Current-fed systems can also be used for dual targets. The
`configuration shown in Figure 6 (essentially a pair of Figure 4
`circuits) is the subject of several patent applications and one
`issued patentllt in Germany. Its use for depositing insulating films
`by reactive sputtering is also covered by a US patent121•
`
`The dual-cathode configuration shown in Figure 6 has
`unique features. Because of the lack of a transformer, the user
`has complete freedom in setting the current levels and the pulse
`widths of the power delivered to the two cathodes. This permits
`the use of the dual-cathode approach-which greatly alleviates
`the disappearing anode problem, while supplying each of the
`targets with a different material running at different voltages,
`currents, and powers that can be varied during a deposition to
`permit continuous variation in film properties. Such a system
`(using reactive sputtering) can create dielectric films with
`graded index of refraction, for example.
`
`Arc detection in either the single- or dual-target
`configuration is particularly easy, because for a constant current,
`the arc represents a large drop in voltage. Simple voltage(cid:173)
`comparing circuits can detect an arc in as little as 50 ns, and the
`closing of the parallel switch (or both switches in Figure 6) will
`quench the arc with very little energy delivered to it. Pulsed de
`power supplies operating at the 120 kW level are available
`commercially that deliver as little as 100 millijoules to an arc.
`
`Hybrid Current-Source;Voltage-Source Systems
`Several power systems are available that are hybrids,
`acting as a current source in one period and a voltage source
`in a second period. Slightly different configurations have been
`used, but all of them are roughly equivalent to the circuits
`shown in Figure 7. These have all been designed for use with
`single targets. The constant current feature of the series
`inductor is used to produce a rapid current rise for reinitializa(cid:173)
`tion of the plasma current after the interruption, and the
`auxiliary voltage source ( to which the switch is connected in
`Figure 7B) aids in overcoming any inductance of the leads to
`the target. The transformer action of the tapped inductor in
`Figure 7 A provides the equivalent voltage as the auxiliary
`source. This configuration is patented 121141• Some papers have
`been written claiming a preferential sputtering effect of the
`voltage source due to an excess reverse voltage appearing on
`insulating islands in this configuration, but the existence of such
`
`4
`
`an effect is very doubtful since there does not appear to be a
`physical mechanism for obtaining the excess reverse voltage
`on the insulating islands.
`
`Figure 7A.
`
`Tapped Inductor
`
`Semiconductor
`Switch
`
`Inductor
`
`Semiconductor
`Switch
`
`+ Auxilary
`Power
`Source
`
`Cathode
`
`Anode
`
`Chamber
`
`Cathode
`
`Anode
`
`Chamber
`
`Figure 78.
`
`Sinusoidal Systems
`Sinusoidal currents can be generated by a variety of circuits,
`but the most efficient (and by far the most used today) is a
`circuit composed of electronic switches, creating a square wave
`of voltage, which is then impressed upon a series resonant L-C
`circuit (some power supplies use a parallel resonant system).
`This configuration produces a sinusoidal current, which is
`then delivered to a transformer for impedance matching. The
`transformer output can be delivered to a single target or to
`dual targets and may also be used for CVD applications. Power
`adjustment (regulation) is accomplished either by controlling
`the pulse width of the switches or by controlling the peak
`voltage with a preregulator. As the on-time of the switches is
`shortened to less than 50% of the period, the current waveform
`will be increasingly distorted; use of a preregulator eliminates
`
`
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`POWER SUPPLIES FOR PULSED PLASMA TECHNOLOGIES: STATE-OF-THE-ART AND OUTLOOK
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`damage to the system in the case of a hard arc, a drop in average
`voltage (i.e., the RMS voltage averaged over several cycles) is
`used to determine the presence of such an arc-in which case
`all the switches are opened for a recovery period. The energy
`stored in the resonant L-C circuit is then discharged into the
`arc. After enough time has passed for the arc to extinguish,
`circuit operation is resumed. Since there is an unavoidable delay
`in arc detection-especially if the circuit Q is high, this
`arrangement can result in a large energy being delivered to the
`arc. A more complex system will detect the arc by comparing
`the integral of a half cycle of the sinusoid with the integral of
`the prior half cycle; a major disparity indicates an arc. This
`guarantees the arc will be detected in at most one-half of the
`period of the sinusoid. By clever arrangement of the switches,
`the energy stored in the resonant circuit can be partially
`diverted into the input power supply and if the circuit Q is kept
`low, the total energy delivered to an arc can be kept to a
`minimum.
`
`MEASUREMENT IN PULSED SYSTEMS
`
`Pulsed DC Systems
`In these systems, the usual setup is to measure the main de
`power, and many users assume that this is the power delivered to
`the plasma. This is not the case, and a correction must be made
`to the measured de values of voltage and current.
`A de pulsing unit (such as that shown in Figures 7 A and
`7B) acts as a de transformer if the switch is operated at a pulse
`width trev and frequency f. While the power is unchanged
`(neglecting los.ses in the pulsing unit), the voltage and current
`will be modified by the duty cycle factor 11= 1-trevf, as follows:
`
`Y plasma = V ps / 11
`
`The apparent drop in impedance (drop in voltage and
`increase in current as read by the power supply's metering) will
`occur when the pulsing is begun and may be surprising to the
`new user. It should be pointed out that the current in the
`plasma is about the same before and after the pulsing is started,
`while the voltage is transformed (increased) by the factor 11·1
`•
`Thus, the peak power during the period the switch is off is
`raised by the factor 1/11, while the average power is the same
`whether the plasma is pulsed or not, again neglecting losses in
`the pulsing unit. In the following, we will account for the
`pulsing losses.
`
`this effect. The circuit is shown in Figure 8, and typical
`waveforms are shown in Figure 9. Since the output is a quasi(cid:173)
`sinusoidal current, the output impedance is high.
`
`AC/DC Converter
`and Preregulator
`
`I
`
`- L
`
`-C Resonant
`Circuit
`
`Figure 8. Sinusoidal Current Generator
`
`Dual
`Cathode
`
`Chamber
`
`Voltage, metallic mode
`Voltage, poisoned mode
`
`Figure 9.
`
`Arc-handling is more complex in sinusoidal systems. While
`it might seem that voltage-sensed arc detection would be easy
`(as in a pulsed current-fed system), the problem is made difficult
`by the highly nonsinusoidal nature of the voltage waveform.
`
`In the simplest arc-handling approach, arcs are simply
`ignored on the assumption that they will be extinguished by the
`reversal of the current on the following half cycle. To prevent
`.... -· -'-· -. -. -. -·- ·-· -. -. -. - . -. -·-. -. -. -. -..... -· - . - . - . - . - ·- ·-. -·-. -. - . -. -. -· -. -. -. -. -. -. -· - . -. -. -· -. -. -. - . - . - . - . -. -. -. -. - ' -. - ' -' - . - . - . -·-. -. -. -. -..
`5
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`Case 6:20-cv-00636-ADA Document 48-18 Filed 02/16/21 Page 7 of 9
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`POWER SUPPLIES FOR PULSED PLASMA TECHNOLOGIES: STATE-OF-THE-ART AND OUTLOOK
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`more complex approaches must be used. It is important to
`understand the measurement method, as this can affect many
`characteristics of the power supply. For example, the cost of a
`supply is dependent upon the power level, and in comparing the
`cost of equipment, one obviously needs to know if the 120 kW
`power supply one is contemplating can only deliver 70 kW to
`80 kW to a plasma due to unmeasured losses in its oscillator and
`output sections.
`
`REACTIVE GAS CONTROL
`A serious problem with reactive sputtering (a common
`use of pulsed power supplies) is control of the reactive gas.
`This is large enough to be the topic of a separate paper, but
`for now we can say that several means have been used. The
`well-known hysteresis phenomenon prevents the use of simple
`mass flow control. Fast valves (with response times -1 ms)
`have been used and controlled to regulate the target voltage,
`the plasma emission, or the partial pressure of the reactive gas.
`An alternative has been used that varies the power at slow
`(chemical) rates to inhibit the hysteresis effect.
`
`OUTLOOK
`Development of nonsinusoidal pulsed systems (particularly
`at high powers) has been slow. The first pulse systems designed
`as voltage sources (see Figure 3) were developed up to the
`100 kW level, but reliability problems and high cost prevented
`general acceptance. Low-power current-fed units for both
`single-target and dual-target operation (Figures 4 and 6) have
`been available for about five years, but a high power (120 kW)
`counterpart to the sinusoidal power systems has only now
`become available. This unit operates in dual-target mode
`(Figure 6) up to 35 kHz and in single-target mode (Figure 4)
`up to 60 kHz and can deliver 250 A into each target, with
`independent adjustment of the current and the pulse width for
`each target. A 180 kW version is now under development and
`higher powers (up to 400 kW) are planned in the future.
`
`NOTES
`1 US Patent 5,576,939
`
`2 US Patent 5,718,814
`
`J DE patent 4,438,463
`
`4 US Patent 5,427,669
`
`In the passive circuit of Figure 7 A, there are losses in the
`pulsing unit roughly proportional to the power:
`
`and the above equations become
`
`V plasma = V ps / Tl
`
`lptasma = Tl kips
`
`P plasma = kP ps
`
`This latter set of equations hold for a passive pulsing unit
`like that of Figure 7 A, where the plasma power is always less
`than the input (metered) power. If the equivalent circuit of
`Figure 7B is implemented directly ( with an actual power supply
`for the voltage source), this auxiliary power supply can also be
`delivering power to the plasma. The power in this case can be
`more than that indicated on the meters of the main power
`supply (by an amount that depends upon the actual voltages,
`frequency, and duty cycle). This can make such a supply appear
`to be more efficient in pulsing than a passive unit, since not all
`of the real power is being accounted for. In either case, a
`correction must be made to the measured power when making
`sputtering efficiency calculations.
`
`MEASUREMENT IN SINUSOIDAL SYSTEMS
`Some sinusoidal systems originally intended for induction
`heating do not measure power at the output of the supply (i.e.,
`at the plasma). These units may have an oscillator section that
`is comprised of one or more semiconductor switches operating
`into a resonant circuit and transformer ( whose secondary is
`connected to the plasma). The frequency of oscillation usually is
`controlled so that the circuit is operating in-phase with the
`resonance, even in the face of changes in the plasma load. This
`permits the energy losses in the semiconductor switches to be
`minimized. It is relatively easy to measure power in sinusoidal
`systems, but in the plasma environment, the waveforms are
`complex, and some manufacturers have elected to simply
`measure the de power coming into the oscillator section. If this
`is done, the measured power includes not only the power going
`to the plasma, but also the power lost in the oscillator circuits,
`the resonant circuit, and the output transformer. Such losses can
`be substantial and can easily reach 30% to 50% of the delivered
`power. At the lower frequencies, the most common solution to
`direct measurement of the plasma power is to accurately
`measure the voltage and current in real-time and to deliver
`them to a multiplier circuit. The output of this circuit is the
`product ofV(t) and I(t) (the instantaneous power), which can
`be averaged or filtered to produce an average power signal. This
`can be done easily up to a few MHz, but at higher frequencies
`
`6
`
`
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`POWER SUPPLIES FOR PULSED PLASMA TECHNOLOGIES: STATE-OF-THE-ART AND OUTLOOK
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`LEXICON
`There is a lot of confusion in the literature about the use of
`pulsed technology terms, and it would be worthwhile here to
`define a few of the more widely used terms. Such definitions are
`to some extent arbitrary, and I do not claim to have done more
`than to indulge my own preferences, but as there exists at
`present no well defined lexicon, I offer my own here.
`
`Arc
`
`Duty Cycle
`
`An arc is a transition from the high(cid:173)
`voltage (abnormal glow) region (wherein
`the voltage rises with increasing current)
`to a low-voltage region ( wherein the
`voltage falls with increasing current).
`A bipolar arc is an arc that can conduct
`current in either direction (generally
`from a metal surface to another metal
`surface) sustained by metal-ion formation
`at the cathode. A hard arc is an arc that
`persists after brief arc-control measures
`have been taken ( e.g., reversal of
`voltage or removal of power for a few
`microseconds). A micro arc is an arc
`that is extinguished by brief arc-control
`measures; also used to mean an arc
`that has extinguished itself without
`outside measures.
`
`Given a period of on-time (during
`which power is applied) and a period of
`off-time (during which power is either off
`or applied at a different level), the duty
`cycle is the ratio of the on-time to the
`sum of the on- and off-times.
`
`Power, Plasma
`
`Power, Pulsed
`
`Power, RMS
`
`Pulsing
`
`The rate of energy flow into a system
`(i.e., through the chamber wall).
`Generally, losses in the leads to-and
`inside of-the chamber are ignored as
`they are often small compared to the
`total power. The plasma power may be
`dissipated in the target, shields, chamber
`walls and other parts, and substrate, but
`it is all considered plasma power.
`
`This term is ill-defined and should not be
`used. Some consider this the same as peak
`power, others the same as average power,
`and some use this for RMS power.
`
`The heating value of the power.
`Obtained by integrating the product
`of the voltage and the current over the
`period of a repetitive waveform and
`dividing by the period.
`
`• Power containing a periodic transient
`followed by a return to steady state
`
`• Power consisting of a periodic
`variation between two states
`
`Pulsing, Asymmetrical In general, a power delivery waveform
`that has no point of symmetry.
`That is, there is no time (ts) such
`that P( ts - t) ±P( ts + t). In a dual(cid:173)
`magnetron system, this is a power
`delivery method that permits
`independent adjustment of the peak
`power to the two targets.
`
`Off, and On-Tunes See duty cycle.
`
`Pulsing, Bipolar
`
`• A power delivery waveform that
`reverses the sign of the voltage and
`current
`
`• A floating power delivery system that
`supplies power to two sputtering
`targets such that each is the anode for
`the other
`
`A power delivery system in which the
`voltage and current do not reverse sign.
`
`A power supply that tends to have a
`constant current output ( i.e., whose
`output voltage is proportional to the
`plasma [load] impedance).
`
`A power supply that tends to have a
`constant voltage output (i.e., whose
`output current is inversely proportional
`to the plasma [load] impedance).
`-. - . - . -·- ·-. -·-. -·-. -. -. -. -. -. -. - ' - ' - ' -·-' -. -. -. -. -·-. -· -. -. -'-· -·-· -. -. -·-. -· -·-· -· -. - ' -'-· -. -. -·-. -. -·-. -. -·-. -. - . -. -. - . -·-·- ·-. -· -· -·- ·-. -. -..
`7
`
`Overshoot
`
`Power, Average
`
`Power, Measured
`
`Power, Peak
`
`A transient response wherein the desired
`quantity ( voltage, current, or power)
`exceeds the desired value before settling
`to its (desired) steady-state level.
`
`In a repetitive cycle, the total energy
`delivered by the power supply divided by
`the cycle time or period of the repetitive
`waveform.
`
`The power indicated by the measurement
`circuits of a power supply. Depending
`upon the placement of the measurement
`circuits and the architecture of the
`supply, this may be different from the
`actual power delivered to the plasma.
`
`The maximum rate of energy flow in a
`repetitive cycle.
`
`Pulsing, Unipolar
`
`Source, Current
`
`Source, Voltage
`
`
`
`Case 6:20-cv-00636-ADA Document 48-18 Filed 02/16/21 Page 9 of 9
`
`POWER SUPPLIES FOR PULSED PLASMA TECHNOLOGIES: STATE-OF-THE-ART AND OUTLOOK
`
`1\ -C ADVANCED
`L.l ENERGY®
`
`© Advanced Energy Industries, Inc. 1999
`All rights reserved. Printed in USA
`SL,,WHITE9,270-0I IM 03/01
`
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