`Exhibit 2005
`
`
`
`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`_____________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`_____________________
`
`
` TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.,
`TSMC NORTH AMERICA CORPORATION,
`FUJITSU SEMICONDUCTOR LIMITED,
`FUJITSU SEMICONDUCTOR AMERICA, INC.,
`ADVANCED MICRO DEVICES, INC., RENESAS ELECTRONICS
`CORPORATION, RENESAS ELECTRONICS AMERICA, INC.,
`GLOBALFOUNDRIES U.S., INC., GLOBALFOUNDRIES DRESDEN
`MODULE ONE LLC & CO. KG, GLOBALFOUNDRIES DRESDEN
`MODULE TWO LLC & CO. KG, TOSHIBA AMERICA ELECTRONIC
`COMPONENTS, INC., TOSHIBA AMERICA INC., TOSHIBA
`AMERICA INFORMATION SYSTEMS, INC.,
`TOSHIBA CORPORATION, and
`THE GILLETTE COMPANY,
`Petitioners
`
`v.
`
`ZOND, LLC
`Patent Owner
`
`U.S. Patent No. 6,853,142
`
`_____________________
`
`Inter Partes Review Case Nos. IPR2014-
`00818, 00819, 00821, 00827, 01098
`
`
`
`_____________________
`
`DECLARATION OF LARRY D. HARTSOUGH, Ph.D.
`
`
`
`I, Larry Hartsough, do hereby declare:
`
`
`
`
`
`1.
`
`I am making this declaration at the request of patent
`
`owner Zond, LLC, in the matter of the Inter Partes Reviews (IPRs) of
`
`U.S. Patent No. 6,853,142 (the “’142 Patent”), as set forth in the above
`
`caption.
`
`2.
`
`I am being compensated for my work in this matter at
`
`the rate of $300 per hour. My compensation in no way depends on the
`
`outcome of this proceeding.
`
`3.
`
`This list of materials I considered in forming the
`
`opinions set forth in this declaration includes the ’142 patent, the file
`
`history of the ’142 patent, the Petitions for Inter Partes Review and the
`
`exhibits, the PTAB’s Institution Decisions, the transcript of the
`
`deposition of the Petitioners’ expert on the ’142 patent, and the prior
`
`art references discussed below.
`
`I.
`
`Education and Professional Background
`
`4. My formal education is as follows. I received a Bachelors
`
`of Science degree in 1965, Master of Science degree in 1967, and
`
`Ph.D. in 1971, all in Materials Science/Engineering from the University
`
`of California, Berkeley.
`
`5.
`
`I have worked
`
`in
`
`the semiconductor
`
`industry
`
`for
`
`
`
`approximately 30 years. My experience includes thin film deposition,
`
`vacuum system design, and plasma processing of materials. I made
`
`significant contributions to the development of magnetron sputtering
`
`hardware and processes for the metallization of silicon integrated
`
`circuits. Since the late 1980’s, I have also been instrumental in the
`
`development of standards for semiconductor fabrication equipment
`
`published by the SEMI trade organization.
`
`6.
`
`From 1971-1974, I was a research metallurgist in the thin
`
`film development lab of Optical Coating Laboratory, Inc. In 1975 and
`
`1976, I developed and demonstrated thin film applications and
`
`hardware for an in-line system at Airco Temescal. During my tenure
`
`(1977-1981) at Perkin Elmer, Plasma Products Division, I served in a
`
`number of capacities from Senior Staff Scientist, to Manager of the
`
`Advanced Development activity, to Manager of the Applications
`
`Laboratory. In 1981, I co-founded a semiconductor equipment
`
`company, Gryphon Products, and was VP of Engineering during
`
`development of the product. From 1984-1988, I was the Advanced
`
`Development Manager for Gryphon, developing new hardware and
`
`process capabilities. During 1988-1990, I was Project Manager at
`
`General Signal Thinfilm on a project to develop and prototype an
`
`
`
`advanced cluster tool for making thin films. From 1991-2002, I was
`
`Manager of PVD (physical vapor deposition) Source Engineering for
`
`Varian Associates, Thin Film Systems, and then for Novellus Systems,
`
`after they purchased TFS. Since then, I have been consulting full time
`
`doing business as UA Associates, where my consulting work includes
`
`product development projects,
`
`film
`
`failure analysis, project
`
`management, technical presentations and litigation support.
`
`7.
`
`Throughout my career,
`
`I have developed and/or
`
`demonstrated processes and equipment for making thin films,
`
`including Al, Ti-W, Ta, and Cu metallization of silicon wafers, RF
`
`sputtering and etching, and both RF and dc magnetron reactive
`
`sputtering, for example SiO2, Al2O3, ITO (Indium-Tin Oxide), TiN, and
`
`TaN. I have been in charge of the development of two sputter
`
`deposition systems from conception to prototype and release to
`
`manufacturing. I have also specialized in the development and
`
`improvement of magnetically enhanced sputter cathodes. I have
`
`experience with related technology areas, such as wafer heating,
`
`power supply evaluation, wafer cooling, ion beam sources, wafer
`
`handling by electrostatics, process pressure control,
`
`in-situ
`
`wafer/process monitoring, cryogenic pumping, getter pumping, sputter
`
`
`
`target development, and physical, electrical and optical properties of
`
`thin films.
`
`8.
`
`I am a member of a number of professional organizations
`
`including the American Vacuum Society, Sigma Xi (the Scientific
`
`Research Society), and as a referee for the Journal of Vacuum Science
`
`& Technology. I have been a leader in the development of SEMI
`
`Standards for cluster tools and 300mm equipment, including holding
`
`various co-chair positions on various standards task forces. I have
`
`previously served as a member of the US Department of Commerce’s
`
`Semiconductor Technical Advisory Committee.
`
`9.
`
`I have co-authored many papers,
`
`reports, and
`
`presentations relating to semiconductor processing, equipment, and
`
`materials, including the following:
`
`a.
`
`P. S. McLeod and L. D. Hartsough, "High-Rate
`
`Sputtering of Aluminum for Metalization of Integrated
`
`Circuits", J. Vac. Sci. Technol., 14 263 (1977).
`
`b.
`
`D. R. Denison and L. D. Hartsough, "Copper
`
`Distribution in Sputtered Al/Cu Films", J. Vac. Sci.
`
`Technol., 17 1326 (1980).
`
`c.
`
`D. R. Denison and L. D. Hartsough, "Step Coverage
`
`in Multiple Pass Sputter Deposition" J. Vac. Sci. Technol.,
`
`A3 686 (1985).
`
`
`
`d. G. C. D’Couto, G. Tkach, K. A. Ashtiani, L.
`
`Hartsough, E. Kim, R. Mulpuri, D. B. Lee, K. Levy, and M.
`
`Fissel; S. Choi, S.-M. Choi, H.-D. Lee, and H. –K. Kang, “In
`
`situ physical vapor deposition of ionized Ti and TiN thin
`
`films using hollow cathode magnetron plasma source” J.
`
`Vac. Sci. Technol. B 19(1) 244 (2001).
`
` My areas of expertise include sputter deposition hardware and
`
`
`
`processes, thin film deposition system design and thin film properties.
`
`I am a named inventor on twelve United States patents covering
`
`apparatus, methods or processes in the fields of thin film deposition
`
`and etching. A copy of my CV is attached as Attachment A.
`
`II. Summary of Opinions
`
`10.
`
` It is my opinion that none of the claims of the ‘142 patent
`
`are obvious.
`
`III. LEGAL STANDARDS
`
`11.
`
`In this section I describe my understanding of certain legal
`
`standards. I have been informed of these legal standards by Zond’s
`
`attorneys. I am not an attorney and I am relying only on instructions
`
`from Zond’s attorneys for these legal standards.
`
`
`
`A. Level of Ordinary Skill in the Art
`
`In my opinion, given the disclosure of the ‘142 Patent, I
`
`12.
`
`consider a person of ordinary skill in the art at the time of filing of the
`
`‘142 Patent to be someone who holds at least a bachelor of science
`
`degree in physics, material science, or electrical/computer engineering
`
`with at least two years of work experience or equivalent in the field of
`
`development of` plasma-based processing equipment. I met or
`
`exceeded the requirements for one of ordinary skill in the art at the time
`
`of
`
`the
`
`invention and continue
`
`to meet and/or exceed
`
`those
`
`requirements.
`
`B. Legal Standards for Anticipation
`
`I understand that a claim is anticipated under 35 U.S.C. §
`
`13.
`
`102 if (i) each and every element and limitation of the claim at issue is
`
`found either expressly or inherently in a single prior art reference, and
`
`(ii) the elements and limitations are arranged in the prior art reference
`
`in the same way as recited in the claims at issue.
`
`C. Legal Standards for Obviousness
`
`I understand that obviousness must be analyzed from the
`
`14.
`
`perspective of a person of ordinary skill in the relevant art at the time
`
`the invention was made. In analyzing obviousness, I understand that
`
`
`
`it is important to understand the scope of the claims, the level of skill
`
`in the relevant art, and the scope and content of the prior art, the
`
`differences between the prior art and the claims.
`
`15.
`
`I understand that even if a patent is not anticipated, it is still
`
`invalid if the differences between the claimed subject matter and the
`
`prior art are such that the subject matter as a whole would have been
`
`obvious at the time the invention was made to a person of ordinary skill
`
`in the pertinent art.
`
`16.
`
`I understand that a person of ordinary skill in the art
`
`provides a reference point from which the prior art and claimed
`
`invention should be viewed. This reference point prevents one from
`
`using his or her own insight or hindsight in deciding whether a claim is
`
`obvious.
`
`17.
`
`I also understand that an obviousness determination
`
`includes the consideration of various factors such as (1) the scope and
`
`content of the prior art; (2) the differences between the prior art and
`
`the asserted claims; and (3) the level of ordinary skill in the pertinent
`
`art.
`
`18.
`
`I also understand that a party seeking to invalidate a patent
`
`as obvious must demonstrate that a person of ordinary skill in the art
`
`
`
`would have been motivated to combine the teachings of the prior art
`
`references to achieve the claimed invention, and that the person of
`
`ordinary skill in the art would have had a reasonable expectation of
`
`success in doing so. This is determined at the time the invention was
`
`made. I understand that this temporal requirement prevents the
`
`forbidden use of hindsight. I also understand that rejections for
`
`obviousness cannot be sustained by mere conclusory statements and
`
`that the Petitioners must show some reason why a person of ordinary
`
`skill in the art would have thought to combine particular available
`
`elements of knowledge, as evidenced by the prior art, to reach the
`
`claimed invention.” I also understand that the motivation to combine
`
`inquiry focuses heavily on “scope and content of the prior art” and the
`
`“level of ordinary skill in the pertinent art.”
`
`19.
`
`I have been informed and understand that the obviousness
`
`analysis requires a comparison of the properly construed claim
`
`language to the prior art on a limitation-by-limitation basis.
`
`IV. TECHNOLOGY BACKGROUND AND THE ’142 PATENT
`
`
`
`20.
`
`The prior art references cited in the Petition and the
`
`Board’s Decision (Wang, Lantsman, Mozgrin and Kudryavtsev)
`
`
`
`describe pulses for generating a plasma, but do not disclose the type
`
`of method and apparatus described in the ‘142 patent and its claims.
`
`A. Voltage, current, impedance and power
`
`21.
`
`As is commonly known, when a voltage “V” is applied
`
`across an impedance “I,” an electric field is generated that forces a
`
`current I to flow through the impedance. For purely resistive
`
`impedance, the relation between the voltage and the resultant current
`
`is given by: V = I * R.
`
`22.
`
`A common analogy is that voltage is like a pressure that
`
`causes charge particles like electrons and ions to flow (i.e., current),
`
`and the amount of current depends on the magnitude of the pressure
`
`(voltage) and the amount of resistance or impedance that inhibits the
`
`flow. The ‘142 patent and the prior art considered here involve the flow
`
`of current through an assembly having a pair of electrodes with a
`
`plasma in the region between them. The effective impedance of such
`
`an assembly varies greatly with the density of charged particles in the
`
`region between the electrodes. Although such an impedance is more
`
`complex than the simple resistive impendence of the above equation,
`
`the general relation is similar: a voltage between the electrode
`
`assembly forces a current to flow through the plasma, such that the
`
`
`
`amount of current is determined by the amplitude of the voltage and
`
`the impedance of the plasma. Thus, the current through the electrode
`
`assembly increases with the electrode voltage and, for a given
`
`electrode voltage, the current will increase with a drop in the
`
`impedance of the plasma.
`
`23.
`
`The impedance varies with the charge density of the
`
`plasma: With a high density of charged particle the impedance is
`
`relatively small, and with a low density of charge particles the
`
`impedance is relatively large. Simply, the more ions and electrons to
`
`carry the charge, the less resistance. However, the charges and fields
`
`react with each other in a very complicated manner.
`
`24.
`
`In response to the electric field in the region between the
`
`electrodes (i.e., the voltage across the electrodes), all charged
`
`particles in the region (the electrons and positive ions) feel a force that
`
`propels them to flow. This flow is an electric current “I.” Obviously,
`
`the amount of current depends upon the number of charged particles.
`
`When there are no charged particles (i.e., no plasma), there is no
`
`current flow in response to the electric field. In this condition, the
`
`impendence of the electrode assembly is extremely high, like that of
`
`an open circuit. But when there is a dense plasma between the
`
`
`
`electrodes (with many charged particles), a substantial current will flow
`
`in response to the electric field. In this condition, the impendence of
`
`the electrode assembly is very low. Thus, in general, the impedance
`
`of an electrode assembly varies greatly with the charge density of the
`
`plasma: The impedance is effectively infinite (an open circuit) when
`
`there is no plasma, and is very low when the charge density is very
`
`high.
`
`25.
`
`It is also well known that electric power (P) is the product
`
`of voltage (V) and current (I): P = V * I. This too is a complex
`
`relationship. When the voltage and current are perfectly in phase, then
`
`one may simply multiply them to yield the power. Thus, for a given
`
`voltage across an electrode assembly, the amount of power will
`
`depend on the amount of corresponding current flowing through the
`
`electrode assembly. If there is no current flow (such as when there is
`
`no plasma between the electrodes), the power is zero, even if the
`
`voltage across the electrodes is very large. Similarly, at very low
`
`electrode voltages, the power can still be quite high if the current is
`
`large.
`
`26.
`
`To provide context for understanding this aspect of the ‘142
`
`patent, I consider below some known basic principles of control
`
`
`
`systems (such as used in all power supplies and all such control
`
`systems) for controlling a parameter such as voltage amplitude.
`
`B. Control systems
`
`27.
`
`The power supply mentioned in the ‘142 patent is an
`
`example of a control system. This system controls the voltage
`
`amplitude of a voltage pulse. A simplified block diagram of a common
`
`feedback control system is shown the figure below from a text by
`
`Eronini.1
`
`
`
`Figure 1 Control system simplified block diagram
`
`The “reference input signal” represents a “desired value” or “set-
`
`
`1 Ex. 2010, Eronini Umez-Eronini, System Dynamics and Control, Brooks Cole
`
`Publishing Co., CA, 1999, pp. 10-13.
`
`
`
`
`
`point” of the controller. The “forward elements” directly control the
`
`“controlled variable.” In response to the difference between the set-
`
`point and a feedback signal (which represents the condition of the
`
`controlled variable), the forward elements direct the controlled variable
`
`in an attempt to reduce the difference to zero, thereby causing the
`
`controlled variable to equal the set point value.
`
`28.
`
`For example, the set-point for filling a water tank may be
`
`1,000 gallons, or full. The desired value, set-point or desired level is
`
`the value “full” or “1000 gallons.” An open loop control system might
`
`just fill the tank for a pre-calibrated time that result in the tank being
`
`full. The control system might be set to fill the tank once per day based
`
`on historical water usage. However, if water usage is not consistent,
`
`the tank may run empty before it is filled, or may overflow because
`
`there was less water usage than normal. On the other hand, a closed
`
`loop system such as shown above uses feedback control. For
`
`example, it measures the water level, and only adds the needed
`
`amount. It might have a switch or sensor that detects when the tank is
`
`full, and turns off the flow of water. The set-point is the desired value.
`
`“Here the comparison of the tank level signal with the desired value of
`
`the tank level (entered into the system as a set-point setting) and the
`
`
`
`turning of the pump on or off are all performed by appropriate hardware
`
`in the controller.” 2 Further, a closed loop system could be left on to fill
`
`the tank if the level dropped to low. “In feedback control, a
`
`measurement of the output of a system is used to modify its input in
`
`such a way that the output stays near the desired value3.”
`
`
`
`C. Set point (Controlled Parameter)
`29. The parameter that is directed to a desired value is called
`
`the “controlled variable,” as shown in the figure from Eronini. Eronini’s
`
`diagram also shows that while controlling the “controlled variable,” the
`
`system may “manipulate” another control parameter that Eronini calls
`
`the “manipulated variable.”
`
`For example, Eronini’s text on control systems shows a control
`
`system that directs the “controlled variable” to its desired value (or “set
`
`point”):
`
`
`2 Ex. 2007, Eronini Umez-Eronini, System Dynamics and Control, Brooks
`
`Cole Publishing Co., CA, 1999, pp. 10-13.
`
`3 Id. at p. 12.
`
`
`
`
`
`30.
`
`Eronini’s diagram also shows that while controlling the
`
`“controlled variable,” the system may “manipulate” another control
`
`parameter that Eronini calls the “manipulated variable.” Another
`
`reference by Weyrick uses the same terminology as Eronini:
`
` “The controlled output is the process quantity being
`
`controlled.”
`
` “The manipulated variable is the control signal which the
`
`control elements process.”
`
`
`
`31.
`
` Similarly, Kua and Sinka also show that the “controlled
`
`parameter” is widely understood to mean the parameter being
`
`controlled by the control system.4
`
`
`4 Ex. 2009, Kua; Ex. 2006, Sinka.
`
`
`
`32.
`
` With this understanding, I now consider the difference
`
`between controlling the amplitude of a voltage and controlling the
`
`power.
`
`D. Power Control vs Voltage Control
`
`33.
`
` To demonstrate the difference between the control of
`
`voltage and the control of power, I will refer to the generic diagram of
`
`a feedback control system from Eronini, shown above. In a system for
`
`controlling voltage, the set point is a specified voltage and the
`
`“controlled variable” obviously is voltage. Thus, in a feedback control
`
`system as shown, a feedback signal representative of the measured
`
`voltage is fed back and compared to the desired voltage level or “set
`
`point.” Based on the difference between the measured voltage and
`
`the desired voltage or set point, the forward elements are instructed to
`
`drive or restrain the voltage in an attempt to move the actual voltage to
`
`match the desired voltage.
`
`34.
`
`In a system for controlling power, the set point is a specified
`
`power value and the controlled variable is power. In such a system,
`
`the voltage and/or current can be driven by the feed forward elements
`
`to whatever levels are needed to achieve the target power level. Thus,
`
`in the example of a system for controlling the power of a plasma
`
`
`
`electrode assembly, if there is no plasma between the electrodes (and
`
`therefore little or no current) a controller attempting to achieve a target
`
`power level will drive the voltage extremely high in an attempt to
`
`achieve the target power P, i.e., P = V * I, (because I is very low or zero
`
`in this situation).
`
`35.
`
`Thus, in a control system for controlling power to a desired
`
`set point, voltage will vary as the controller attempts to achieve the
`
`desired power level (i.e., a desired product of voltage and current).
`
`However, the amplitude of the voltage is not controlled and instead the
`
`voltage and/or the current vary as needed to achieve the desired
`
`power.
`
`36.
`
`The rise time of a voltage therefor is a different parameter
`
`than the rise time of power. For example, consider a scenario in which
`
`a voltage source outputs a constant voltage. If that source is
`
`connected across an impedance that gradually drops, the current will
`
`increase as the impedance drops. Since power is the product of
`
`voltage (here a constant) and current, the power too will rise as the
`
`current increases. Thus, in this situation, power rises at rate
`
`determined by the rate at which the impedance decreases. But there
`
`is no rise in voltage because the source maintains a static, constant
`
`
`
`voltage at its output in this example. This demonstrates that a rise time
`
`in voltage is a different parameter than rise time in power.
`
`37.
`
`This example can also be used to demonstrate the
`
`difference between a controlled change in the output of a voltage
`
`source, and a reaction to a change in impedance. If the impedance
`
`drops so fast that the voltage source cannot maintain the voltage at its
`
`target level, the voltage output by the source can drop due to limitations
`
`of the voltage source. This drop in voltage is not a controlled drop,
`
`caused by the power supply in response to a programmed change in
`
`the voltage set point: It is a transient drop caused by a change in the
`
`impedance load that exceeds the capacity of the voltage source.
`
`E. Magnetron Sputtering History and Operation
`
`38.
`
` Since the late 1970s, DC magnetron sputtering has
`
`become the preferred method for the deposition of thin metal films for
`
`many applications, including semiconductor devices and protective
`
`layers on cutting tools. Several significant advantages of this method
`
`over alternatives, such as thermal evaporation or diode sputter
`
`deposition, are higher deposition rate and improved film structure.
`
`39.
`
` The higher deposition rate is possible because the closed
`
`loop magnetic field of the magnetron traps the secondary electrons
`
`
`
`(produced when the inert gas ions bombard the metal target that is
`
`attached to the cathode assembly held at a negative voltage of several
`
`hundreds of volts). These electrons gain energy as they are
`
`accelerated across the dark space. Since most of the voltage drop
`
`from anode to cathode occurs in this region, the electrons arrive in the
`
`discharge region with more than enough energy to ionize the neutral
`
`gas atom there. The crossed electric and magnetic fields create a
`
`force on the electrons that causes them to circulate in a path that
`
`follows the shape of the magnetic loop and is only a few mm from the
`
`face of the target. The circulating current in this loop is about 10x the
`
`anode-cathode current of the sputtering discharge. It is these
`
`electrons that collide with, and create large numbers of ions of, the inert
`
`neutral sputtering gas atoms (usually argon) that have diffused into this
`
`region. The ions are accelerated toward the target and bombard it with
`
`energies that are nearly the full cathode-anode voltage. As the
`
`secondary electrons create an ion, they lose energy and move closer
`
`to the anode. After several ionizing collisions they no longer have
`
`enough energy to create ions. It is the secondary electrons that sustain
`
`a normal magnetron discharge.
`
`40.
`
` The magnetron discharge is characterized by higher
`
`
`
`current and lower voltage (i.e., lower impedance) compared to a diode
`
`discharge. This allows higher powers to be delivered than would be
`
`possible with diode sputtering, because the drop in yield with lower
`
`voltage is more than made up for by the increase in the number of ions.
`
`In DC magnetron sputtering, repeatability of film thickness is usually
`
`achieved by operating the power supply in power control mode and
`
`depositing for a specific time.
`
`41.
`
` The sputtered metal atoms are ejected from the target with
`
`high velocity, compared to evaporation, which contributes to film
`
`adhesion and microstructure. However, this high velocity means that
`
`relatively few of the metal atoms have a chance to become ionized as
`
`they traverse the thin zone of high energy electrons on their way from
`
`the source target to the substrate workpiece (e.g., silicon wafer or razor
`
`blade).
`
`42.
`
` As research progressed over the ensuing decades, the
`
`advantages of increasing the ionization of the sputtered atoms became
`
`evident. Ions impacting the growing film improved qualities such as
`
`hardness, adhesion and density even further. Furthermore, the
`
`trajectories of the incoming ions could be made more perpendicular to
`
`the substrate surface by application of a negative bias. This allowed
`
`
`
`more film to be deposited in the bottom of high aspect ratio holes
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`enabling
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`the production of semiconductor devices with ever-
`
`decreasing geometries.
`
`43.
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` The challenge of increasing the degree of ionization of the
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`sputtered atoms could be met by increasing the chances that they
`
`would encounter an ionizing collision in the space between target and
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`substrate. This could be achieved by expanding the high density
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`plasma into that space. Just increasing the DC power to the
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`magnetron would do this and would increase the power density
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`delivered to the target, increasing the sputtering rate and the ionization
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`of the sputtered atoms. However, this approach, if applied steady
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`state, would require large power supplies and would overheat the
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`target. Therefore, other techniques were developed to meet the
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`challenge.
`
`44. One approach, introduced by Rossnagel and Hopwood5
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`was to create a separately sustained plasma in the target-substrate
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`space. Another was to use the hollow cathode magnetron invention of
`
`
`5 S.M. Rossnagel and J. Hopwood, Journal of Vacuum Science &
`
`Technology 12B (449-453) 1994.
`
`
`
`Helmer6 Yet another approach was to use pulsed DC magnetron
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`sputtering to create a short-lived high density magnetron plasma with
`
`enough time between pulses such that the average power delivered
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`over many pulses did not exceed the steady state power delivery
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`capability of the power supply or the cooling capacity of the cathode.
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`As the density of the plasma increases it also expands, at least partially
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`due to reduced trapping of the electrons circulating within the magnetic
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`field loop. The large circulating current in this loop forms a one-turn
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`(very high amperage) electromagnet that creates a magnetic field
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`opposing the magnetic field produced by the magnetron magnets. This
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`reduction in effective magnetic field allows an increase in width of the
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`sputtering zone and an expansion of the plasma away from the
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`cathode.
`
`45. However, this pulsed approach is accompanied by several
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`risks. An abrupt large increase in applied voltage can cause localized
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`instabilities in electric fields to be large enough to initiate an arc on the
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`cathode, even if a low density discharge is already present. If the high
`
`density plasma is driven to over-expansion it can essentially form a
`
`
`6 U.S. Patent No. 5,482,611.
`
`
`
`short between the cathode and anode leading to a breakdown mode
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`in which no sputtering occurs.
`
`46. There are large changes in plasma impedance that occur
`
`during a pulsed DC magnetron discharge. The more charged particles
`
`within it, the more electrically conducting it becomes. During ignition,
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`the impedance may be in the hundreds of ohms, dropping to the tens
`
`of ohms in the low density mode. In the transition from a low to a high
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`density plasma, the impedance drops to a few ohms, accompanied by
`
`up to two orders of magnitude increase in current. Depending on
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`power supply design and control settings, the density of the plasma
`
`may increase quite unevenly, also leading to the possibility of plasma
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`breakdown or arcs, if the transitions are uncontrolled.
`
`47.
`
` Power supplies in the art prior to the ‘142 patent for DC
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`magnetron sputtering include those that set power for the duration of a
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`deposition step. In power control mode, the output is controlled until
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`the product of discharge voltage and current equals the set power. In
`
`pulsed power mode, as described by Wang, the total energy delivered
`
`during a pulse is controlled.7
`
`
`7 Ex. 1005, Wang, col. 6, lines 16 – 24.
`
`
`
`48. However, such pulsed power systems are prone to arcing
`
`upon igniting the plasma, especially when working with high-power
`
`pulses.8 Such arcing can result in the release of undesirable particles
`
`in the chamber that can contaminate the sample, which is especially
`
`undesirable in semiconductor processing.9
`
`V. Patent 6,853,142
`
`49.
`
` Sputtering systems generate and direct ions from plasma
`
`“to a target surface where the ions physically sputter target material
`
`atoms.”10 Then, “[t]he target material atoms ballistically flow to a
`
`substrate where they deposit as a film of target material.”11 “The
`
`plasma is replenished by electron-ion pairs formed by the collision of
`
`neutral molecules with secondary electrons generated at the target
`
`surface.”12
`
`
`8 Ex. 1001, ‘142 patent, col. 1, lines 38-40; see also Ex. 1005, Wang, col. 7
`
`lines 3-6, 46-48.
`
`9 Ex. 1001, ‘142 patent, col. 1, lines 40-42; see also Ex. 1005, Wang, col. 7
`
`lines 3-6, 46-48.
`
`10 Exhibit 1001, ‘142 patent, col. 1, ll. 9-11.
`
`11 Id. at col. 1, ll. 11-13.
`
`12Id. at col. 1, ll. 32-34.
`
`
`
`50. A planar magnetron sputtering system is one type of
`
`sputtering system.13 “Magnetron sputtering systems use magnetic
`
`fields that are shaped to trap and to concentrate secondary electrons,
`
`which are produced by ion bombardment of the target surface.”14 “The
`
`trapped electrons enhance the efficiency of the discharge and reduce
`
`the energy dissipated by electrons arriving at the substrate.”15
`
`51. But prior art planar magnetron sputtering systems at the
`
`time of the invention of the ‘142 patent experienced “non-uniform
`
`erosion or wear of the target that results in poor target utilization.”16 To
`
`address these problems, researchers increased the applied power and
`
`later pulsed the applied power.17 But increasing the power increased
`
`“the probability of establishing an undesirable electrical discharge (an
`
`electrical arc) in the process chamber.”18 In addition, “very large power
`
`
`13 Id. at col. 1, ll. 36-54.
`
`14 Id. at col. 1, ll. 36-38.
`
`15 Id. at col 1, ll. 52-54.
`
`16 Id. at col. 2, ll. 57-59.
`
`17 Id. at col. 2, l. 60 to col. 3, l. 9.
`
`18 Id. at col. 2, ll. 65-67.
`
`
`
`pulses can still result in undesirable electrical discharges and
`
`undesirable target heating regardless of their duration.”19
`
`52. To overcome the deficiencies of the prior art, Dr.
`
`Chistyakov invented a magnetically enhanced sputtering source
`
`having a particular structure of an anode, cathode, ionization source,
`
`magnet and power supply generating a particular type of voltage pulse
`
`to perform a particular multi-step ionization process without forming an
`
`arc discharge as recited in independent claim 1 and as illustrated in
`
`Fig. 2 of the ’142 patent, reproduced below:
`
`
`
`
`19 Id. at col. 3, ll. 7-9.
`
`
`
`
`
`
`
`53. As illustrated by FIG. 2, Dr. Chistyakov’s magnetically
`
`enhanced sputtering source includes an anode 238 and a cathode
`
`assembly 216. The anode 238 is positioned adjacent to the cathode
`
`assembly “so as to form a gap 244 between the anode 238 and the
`
`cathode assembly 216 that is sufficient to allow current to flow through
`
`a region 245 between the anode 238 and the cathode assembly 216.”20
`
`“The gap 244 and the total volume of region 245 are parameters in the
`
`