(12) United States Patent
`Jewett et al.
`
`USOO639221 OB1
`US 6,392.210 B1
`(10) Patent No.:
`May 21, 2002
`(45) Date of Patent:
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`(54)
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`(76)
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`(*)
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`(21)
`(22)
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`(60)
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`(51)
`(52)
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`(58)
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`METHODS AND APPARATUS FOR RF
`POWER PROCESS OPERATIONS WITH
`AUTOMATIC INPUT POWER CONTROL
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`Inventors: Russell F. Jewett, 10220 Scott Gate
`Ct., Charlotte, NC (US) 28201; Curtis
`C. Camus, 2702 High Plains Ct., Fort
`Collins, CO (US) 80521
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`Notice:
`
`Appl. No.: 09/490,128
`Filed:
`Jan. 24, 2000
`Related U.S. Application Data
`Provisional application No. 60/174,110, filed on Dec. 31,
`1999.
`Int. Cl................................................... H05B 6/06
`U.S. Cl. .................. 219/663; 219/664; 219/121.54;
`323/299; 363/74
`Field of Search ................................. 219/661, 663,
`219/664, 665, 666, 668, 121.57, 121.54,
`137 PS, 130.5, 130.1; 156/345; 323/299,
`303; 315/111.21, 17.3, 464; 204/298.08,
`298.32: 363/73, 74
`
`4,147.910 A 4/1979 Kiuchi et al.
`4,188,520 A
`2/1980 Dills .......................... 219/486
`4,687,896 A
`8/1987 Baik
`5,223,457. A
`6/1993 Mintz et al. ................ 437/225
`5,272,719 A * 12/1993 Cartlidge et al. ........... 219/662
`5,383,019 A
`1/1995 Farrell et al. ............... 356/316
`5,556,549 A * 9/1996 Patricket al. .............. 156/345
`5,654,679 A 8/1997 Mavretic et al. ........... 333/17.3
`5,688,357 A 11/1997 Hanawa ...................... 156/345
`5,723,970 A * 3/1998 Bell ............................ 320/30
`5,892,198 A 4/1999 Barnes et al. .......... 219/121.54
`5.991,170 A * 11/1999 Nagai et al. .................. 363/20
`* cited by examiner
`Primary Examiner Philip H. Leung
`(74) Attorney, Agent, or Firm-Larry Williams
`(57)
`ABSTRACT
`A variable frequency RF power delivery system is used with
`a control System that adjusts the output frequency of the RF
`power delivery System. Frequency adjustments are made So
`as to maintain the required input current and input Voltage
`within the capabilities of the input current and input Voltage
`SOCC.
`
`31 Claims, 6 Drawing Sheets
`
`28
`
`POWER FORM
`SENSOR
`
`POWER FORM
`CONTROLLER
`26
`
`A.
`
`RFAMPLIFER
`
`34
`
`Z
`
`SENSORS AND
`MATCH NETWORK
`
`30
`
`/
`RF COUPLING
`ELEMENT
`
`2O
`
`RF POWER
`PROCESSOR
`
`
`
`CONTROLLER
`FREGUENCY8.
`RF POWER
`
`
`
`V 22
`
`RENO EXHIBIT 2025
`Advanced Energy v. Reno, IPR2021-01397
`
`

`

`U.S. Patent
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`May 21, 2002
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`

`1
`METHODS AND APPARATUS FOR RF
`POWER PROCESS OPERATIONS WITH
`AUTOMATIC INPUT POWER CONTROL
`
`CROSS-REFERENCES
`The present application claims the benefit of U.S. Provi
`sional Patent Application No. 60/174,110, filed on Dec. 31,
`1999. The present application is related to U.S. patent
`application Ser. No. 09/476,020, filed on Dec. 31, 1999, U.S.
`Provisional Patent Application No. 60/174,110, entitled
`“Methods and Apparatus for Process Operations with RF
`Power” by Russell F. Jewett and Curtis C. Camus filed on
`Dec. 31, 1999, U.S. patent application entitled “Methods
`and Apparatus for Igniting and Sustaining Inductively
`Coupled Plasma" filed on Jan. 24, 2000 now U.S. Pat. No.
`6,291,938, and U.S. patent application No. 09/490,496
`entitled “Methods and Apparatus for Plasma Processing” by
`Russell F. Jewett, filed on Jan. 24, 2000, now U.S. Pat. No.
`6,156,667. All of these applications are incorporated herein
`by this reference.
`
`15
`
`BACKGROUND
`This invention relates to improved methods and apparatus
`for controlling input power requirements for delivering radio
`frequency (RF) power for process operations. RF power is
`extensively used in a wide variety of applications for car
`rying out process operations. Exemplary of Such proceSS
`operations is RF induction heating. RF induction heating
`involves coupling RF power to a material that absorbs the
`RF power and converts the RF power into heat. In other
`words, the currents induced in material by the RF power are
`converted into heat because of the electrical resistance of the
`material that absorbs the RF power. In this manner, the RF
`power can be used to heat an object without having physical
`contact between the power Source and the object. This type
`of heating can be used wherein the object is the material that
`absorbs the RF power and is heated directly by the RF
`power. Alternatively, the object may be in contact with or
`near a Second material that absorbS RF power; the Second
`material absorbs the RF power and creates the heat; the heat
`is then transferred to the workpiece by conduction,
`convection, or radiation.
`In another example of RF heating, the RF power can be
`coupled to a gas to produce a thermal plasma. Free electrons
`in the thermal plasma absorb the RF power and are raised to
`high energy levels. These energetic free electrons interact
`with other gas phase species to produce a high temperature
`mixture that can transfer their thermal energy to other gases,
`liquids, or Solids.
`The thermal plasmas mentioned above can be used to
`promote chemical reactions. Chemical reactions can be
`promoted because of the high temperatures of the thermal
`plasma. Alternatively, thermal plasmas are able to promote
`chemical reactions because of the ability of the energetic
`electrons to break chemical bonds and allow chemical
`reactions to occur that would proceed with difficulty under
`non-plasma conditions.
`The manufacture of optical fiber preforms is an example
`of the use of thermal plasmas generated using RF power. The
`RF thermal plasma provides the energy for driving the
`chemical reactions in gas mixtures of Silicon compounds,
`oxygen, and dopants. The chemical reactions cause deposi
`tion of doped Silica layers.
`Another example involving RF power thermal plasmas is
`the operation of high-pressure gas lasers. In gas laser opera
`tion the important characteristic of the RF plasma is the light
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`2
`emission that occurs because of the plasma. The thermal
`energy that is produced is generally not considered impor
`tant to the operation of the laser.
`In other applications, RF power is used to produce non
`thermal plasmas, also referred to as non-equilibrium plas
`mas. The manufacture of Semiconductor devices is one area
`in which non-thermal plasmas are extensively used. The
`non-thermal plasmas are used for etch processes wherein the
`non-thermal plasmas are used to generate reactive Species in
`a gas to accelerate reactions between the Species and a Solid
`Surface. The etch process can be a general removal of
`components on the Surface as in a cleaning proceSS or the
`Selective removal of material from certain areas on the
`Surface through use of a masking material that has been
`previously patterned. Non-thermal plasmas are used to pro
`mote deposition reactions wherein gas phase species are
`caused to react to form a Solid product that deposits on
`Surfaces. During the manufacture of Semiconductor devices,
`etch processes involving RF plasmas and deposition pro
`ceSSes involving RF plasmas are used repeatedly during the
`fabrication process. One of the main benefits of using the
`non-thermal plasma is the ability of the non-thermal plasma
`to Stimulate chemical reactions that would otherwise require
`temperatures that are too high for use in the fabrication of
`Semiconductor devices.
`RF power non-thermal plasmas are also used as cleaning
`processes in manufacture of Semiconductor devices. The
`non-thermal plasmas are commonly used to Strip photoresist
`materials from Semiconductor wafers as part of post etch
`wafer clean procedures. The photoresist material Serves as a
`mask material during etch processes used in patterning the
`Surface of the devices. Resist material is Stripped from the
`Surface of the wafers by creating a non-thermal plasma in a
`gas containing oxidizing Species Such as Oxygen and possi
`bly halogen Species that are capable of reacting with and
`Volatilizing the resist material. In Some applications, the
`non-thermal plasma is maintained at a position upstream of
`the wafer. Reactive Species generated in the non-thermal
`plasma flow downstream and react with the wafer Surface
`for the Stripping process.
`Another cleaning process that uses non-thermal plasmas
`is the cleaning of reaction chambers used in manufacturing
`Semiconductor devices. Sometimes, the reaction chambers
`used in plasma etch processes experience a buildup of
`deposits from the etch process. These deposits must be
`removed as part of the reactor maintenance process. Also,
`the reactors that are used in deposition processes for Semi
`conductor device fabrication undergo a buildup of deposits
`on the reactor walls, the wall deposit must be removed as
`part of reactor maintenance. Non-thermal plasmas generated
`using RF power and gases containing Species that are
`reactive with the deposits have been used to volatilize and
`remove the deposits built up on the walls of etch reactors and
`deposition reactors.
`RF power plasmas have also been used for decomposition
`of chemical compounds that are hazardous or otherwise
`undesirable. Some of the compounds are highly refractory in
`nature and are difficult to decompose. Examples of com
`pounds that have been decomposed or abated with plasmas
`include chlorofluorocarbons (CFC) and perfluorocom
`pounds (PFC).
`The applications given above where RF power is used as
`part of a proceSS makeup only a Small fraction of the
`applications for RF power. There are numerous additional
`processing applications for RF power. However, the meth
`ods and apparatus typically used to deliver RF power have
`
`

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`US 6,392.210 B1
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`15
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`3
`deficiencies and may be inefficient for use in existing
`applications. Some of the deficiencies are common for
`multiple applications. The existing deficiencies in the prior
`methods and apparatus for RF power delivery may limit the
`use of RF power for possible new applications.
`One frequently encountered problem with standard RF
`power delivery Systems is that the equipment is typically
`designed for use at only one Set of optimized input power
`conditions. Specifically, the required input current and input
`Voltage only have a Small range of values for operation of
`the RF power delivery System. The narrow operating con
`ditions for input power in terms of current and Voltage
`presents a problem for the typical AC power Source lines
`available in homes, offices, and factories around the World.
`To accommodate the input power requirements for Standard
`RF power delivery Systems, three phase AC power Sources
`are typically required to assure having adequate current and
`voltage for the power input to the RF power delivery system.
`Providing three phase AC power Sources may require addi
`tional wiring if the three phase AC lines are not already
`available. Consequently, the use of some RF power delivery
`systems can be hindered by the unavailability of three phase
`AC electric power. Furthermore, the variation in the Stan
`dard current and Voltage for AC power lines used in different
`countries can also hinder the use of RF power delivery
`systems. To overcome these problems, the old-style RF
`power delivery Systems have been required to have special
`power converters to accommodate the current and Voltage
`Sources available in each country.
`Based on the variety of possible applications for RF
`power delivery as described above, there are numerous
`situations in which it would be advantageous to have an RF
`power delivery System capable of operating over a wide
`range of input current and Voltage. There is a need for
`improved RF power delivery methods and apparatus that
`require a minimum or no special wiring to access the electric
`power Source. In addition, there is a need for RF power
`delivery Systems that can be plugged into any Standard AC
`power lines that are used in offices and factories all over the
`40
`world. There is a need for RF power delivery methods and
`apparatus that are simple in operation and have the versa
`tility to handle a wide range of input electric power currents
`and Voltages.
`
`25
`
`4
`magnitude of RF power and a specified frequency of the RF
`power, the RF power amplifier requires an input of electric
`power having a particular current and Voltage combination
`i.e. power form. In other words, the RF power amplifier has
`Specific requirements of input current and Voltage in order to
`provide the specified frequency of the RF power.
`Consequently, it is possible to adjust the frequency of the RF
`power and maintain the desired magnitude of the RF power
`So that the required power form of the input power is varied.
`This particular behavior of the RF power amplifier can be
`used with a controller responsive to the input power require
`ments to automatically adjust the frequency of the output RF
`power So as to maintain the required power form of the input
`electric power within the capabilities of the input electric
`power Source.
`The frequency is controlled automatically in order to
`achieve an input requirement of current and Voltage that
`meets the capabilities of the available power source. Further
`adjustments are made in order to achieve desired, preferably
`efficient, RF power delivery to the load. The further adjust
`ments may include changes in the impedance that the RF
`power amplifier Sees in delivering RF power to the load or
`changes in the frequency of the RF power to obtain a
`frequency that is resonant with coupling RF power to the
`load.
`Aspects of the present invention are accomplished using
`a power form controller and a variable frequency RF power
`delivery System. The power form controller is responsive to
`power characteristics of input power to the RF power
`delivery system. The controller provides signals to the RF
`power delivery System to adjust the frequency of the output
`power from the RF power delivery system so that the
`required power form for the input power to the RF power
`delivery System does not exceed the capabilities of the input
`electric power Source.
`In different embodiments of the present invention, the
`variable frequency RF power delivery systems may be of
`different designs and may use different methods of opera
`tion. Examples of variable frequency RF power delivery
`systems are described in 1999 U.S. Pat. No. 5,892,198 to
`Barnes et al., 1997 U.S. Pat. No. 5,654,679 to Mavretic et
`al., 1995 U.S. Pat. No. 5,383,019 to Farrell et al., and 1993
`U.S. Pat. No. 5,223,457 to Mintz et al.; all of these appli
`cations are incorporated herein by this reference.
`Standard variable frequency RF power delivery systems
`typically include a variable frequency RF power amplifier, a
`match network, an RF power coupling element, one or more
`Sensors, and one or more controllers. The Sensor can include
`one or more pickups for deriving information about the RF
`power. The RF power amplifier provides an output RF
`power through the match network to the RF power coupling
`element. The sensor collects information about the RF
`power and provides the information to the controller. The
`controller responds to information input from the Sensor to
`provide control Signals to the RF amplifier to specify the
`magnitude and frequency of the RF power output. The
`controller or another controller may provide Signals to
`control impedance matching if the match is a variable match
`network.
`Standard variable frequency RF power delivery systems
`can be included in embodiments of the present invention. A
`requirement for using Standard variable frequency RF power
`delivery Systems in embodiments of the present invention is
`that the RF power delivery systems must be capable of being
`modified to implement power form control. The power form
`control capability adjusts the base frequency of operation or
`
`35
`
`SUMMARY
`This invention is related to methods and apparatus that
`can overcome deficiencies of known RF power delivery
`Systems. Practicing this invention makes it possible to
`achieve RF power delivery to a load for which the required
`input currents and Voltages are controlled to Stay with in the
`capabilities of currents and Voltages for the available electric
`power Source.
`The electric power characteristics are also referred to as
`power form. Specifically, the electric power characteristics
`are the combination of current and Voltage that makeup the
`electric power. A given quantity of electric power can be
`provided as various combinations of current and Voltage.
`For example, 1000 watts of electric power can have an
`approximate power form of 10 amps at 100 volts, 20 amps
`at 50 volts, or 5 amps at 200 volts.
`Variable frequency RF power amplifiers are capable of
`providing an output RF power for which the frequency of the
`RF power can have values within the frequency range of the
`RF power amplifier. Usually, the frequencies or rather the
`ranges of frequencies are varied as part of delivering the RF
`power to a load for a process operation. For a specified
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`rather the frequency range of operation in response to
`characteristics of input electric power for RF power ampli
`fiers in the RF power delivery systems.
`Alternatively, variable frequency RF power delivery sys
`tems that are more advanced than those commonly known
`may also be used in embodiments of the present invention.
`For example, 1999 United States patent application titled
`“Methods and Apparatus for RFPower Delivery” by Russell
`F. Jewett and Curtis C. Camus filed on Dec. 31, 1999,
`incorporated herein by reference, describes an advanced
`variable frequency RF power delivery system suitable for
`use in embodiments of the present invention.
`An aspect of the present invention is a method of oper
`ating a variable frequency RF power delivery System for
`delivering RF power to a load for a process operation. The
`method is carried out using a variable frequency RF power
`Source. The variable frequency RF power Source includes an
`RF power amplifier, one or more Sensors, and an RF power
`coupling element disposed So as to couple RF power to the
`load. The method includes adjusting at least one of:
`a) frequency of the delivered RF power; and
`b) impedance seen by the RF power Source; in response
`to measurements of RF power delivery efficiency so as
`to achieve desired, preferably efficient, delivery of the
`RF power to the load and also automatically adjusting
`the frequency of the delivered RF power in response to
`a parameter representative of the current and Voltage of
`the electric power input to the RF power amplifier So as
`to maintain the input current and Voltage within the
`limits of the available power Source.
`One embodiment of the present invention is a method of
`operating a variable frequency RF power delivery System for
`delivering RF power to a load for a process operation. The
`method is carried out using a variable frequency RF power
`Source. The variable frequency RF power Source includes an
`RF power amplifier, one or more Sensors, and an RF power
`coupling element disposed So as to couple RF power to the
`load. The method includes adjusting the frequency of the
`delivered RF power in response to a parameter representa
`tive of the RF power delivery efficiency so as to achieve
`efficient delivery of the RF power to the load. The method
`further includes adjusting the frequency of the delivered RF
`power automatically in response to a parameter representa
`tive of the current and Voltage of the electric power input to
`the RF power amplifier So as to maintain the input current
`and voltage within the limits of the available electric power
`SOCC.
`Another aspect of the present invention is an apparatus for
`RF power delivery including a variable frequency RF power
`Source and a control System. The control System is capable
`of adjusting at least one of:
`a) frequency of the delivered RF power; and
`b) impedance seen by the RF power Source; in response
`to the RF power delivery efficiency so as to achieve
`desired, preferably efficient, delivery of the RF power
`to the load. The control System is also capable of
`adjusting the frequency of the delivered RF power in
`response to a parameter representative of the current
`and Voltage of the electric power input to the RF power
`amplifier So as to maintain the input current and Voltage
`within the limits of the available electric power source.
`Another aspect of the present invention is an apparatus for
`RF power delivery including a variable frequency RF power
`Source and a control System. The control System is capable
`of adjusting the frequency of the delivered RF power in
`response to a parameter representative of the RF power
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`6
`delivery efficiency So as to achieve desired, preferably
`efficient, delivery of the RF power to the load and also
`adjusting the frequency of the delivered RF power in
`response to a parameter representative of the input power
`current and Voltage of the electric power input to the RF
`power amplifier So as to maintain the input current and
`voltage within the limits of the available electric power
`SOCC.
`Suitable control Systems for practicing embodiments of
`the present invention can include one or more controllers for
`each of the parameters being controlled. Alternatively, Suit
`able control Systems may include a Single controller that is
`capable of controlling multiple parameters simultaneously.
`In one embodiment, a control System, capable of control
`ling two or more parameters Simultaneously, is used to
`achieve desired, preferably efficient, RF power delivery to a
`load. In addition, the control System is used to automatically
`control the frequency of the delivered RF power in order to
`achieve efficient use of the available input electric power
`characteristics.
`In another embodiment, the control System is capable of
`controlling two or more parameters Simultaneously. The
`control System is used to control the frequency in order to
`achieve desired, preferably efficient, RF power delivery to
`the load. In addition, the control System is used to control the
`frequency in order to achieve efficient use of the available
`input electric power characteristics.
`The power form of the input electric power is directly
`represented by measurements of the current and Voltage of
`the input power. Similarly, the power form of the electric
`power Source is directly represented by the current and
`Voltage available from the electric power Source. One
`embodiment of the present invention includes measuring the
`current and Voltage to obtain the power form of the input
`electric power. Alternative embodiments of the present
`invention can use alternative indicators of the input power
`form. Examples of parameters that are representative of the
`input power form include input electric power current, input
`electric power Voltage, RF power current, and RF power
`Voltage. Examples of Suitable embodiments for controlling
`the power form of the input electric power through adjust
`ments in the RF power frequency include:
`a) minimizing RF voltage by adjusting the RF frequency;
`b) minimizing input electric power voltage by adjusting
`the RF frequency;
`c) maximizing input electric power current by adjusting
`the RF frequency; and
`d) maximizing RF current by adjusting the RF frequency.
`In preferred embodiments the RF voltage and RF
`current are measured at the RF power coupling ele
`ment.
`Numerous control techniques can be used for adjusting
`the frequency to control the input power form in embodi
`ments of the present invention. Examples of control tech
`niques that can be used include incrementing and decre
`menting in fixed amounts, proportional, integral, and
`derivative techniques and combinations thereof.
`According to various aspects of the present invention,
`embodiments of the RF power coupling element can have
`any form suitable for RF power delivery. Exemplary forms
`of RF power coupling elements are antennas, coils, cylin
`drical coils, planar coils, electrodes, rings, parallel plates,
`Screens, and waveguides. Various types of RF power cou
`pling elements are well known in the art.
`In various Separate embodiments of the present invention,
`the load that receives the RF power may use the RF power
`for different applications. Exemplary functions of the loads
`
`

`

`US 6,392.210 B1
`
`7
`for various applications are as follows. The load may absorb
`the RF power to produce heat for a heating proceSS as in RF
`induction heating. The load may absorb the RF power to
`produce a thermal plasma Such as those used for chemical
`processing, materials processing, analytical chemistry, or
`driving optical devices. The load may absorb the RF power
`to produce a non-thermal plasma Such as those used for
`chemical processing or materials processing. The load may
`absorb RF power to produce non-thermal plasmas Such as
`plasmas used for Semiconductor device fabrication pro
`ceSSes like etching, deposition, cleaning, doping, oxidation,
`drying, photoresist Stripping, parts cleaning, reaction cham
`ber cleaning, and annealing. The load may absorb RF power
`to produce a plasma for Stimulating chemical reactions that
`cannot proceed or proceed slowly under non-plasma condi
`tions. The load may absorb RF power to produce a plasma
`for decomposing chemical compounds. The load may
`absorb RF power to produce a plasma for Synthesizing
`chemical compounds.
`In another aspect of the present invention, the delivered
`RF power is used for abatement of gaseous halogenated
`organic compounds, other refractory organic compounds,
`perfluorocompounds, and refractory inorganic compounds.
`The apparatus uses a non-thermal plasma, generated by RF
`power, for generating free radicals in a dielectric reaction
`vessel. In a further aspect of the present invention, the
`treatment of gases is enhanced by the addition of Suitable
`ancillary reaction gases including water, methane, hydrogen,
`ammonia, hydrogen peroxide, oxygen, or mixtures thereof.
`Embodiments of the present invention provide methods
`and apparatus for RF power delivery that automatically
`optimize the frequency of the delivered RF power so as to
`enable use of a wide variety of available power character
`istics for the input power.
`Embodiments of the present invention provide methods
`and apparatus for RF power delivery Such that the apparatus
`has a greater probability of being able to operate with a
`Single phase AC power Source in Substantially any country
`in the world.
`Embodiments of the present invention provide methods
`and apparatus for RF power delivery Such that the apparatus
`automatic attempts to optimize use of the available input
`power Source.
`Embodiments of the present invention provide methods
`and apparatus for RF power delivery for heating as in RF
`induction heating.
`Embodiments of the present invention provide methods
`and apparatus for RF power delivery for generating plasmas.
`Embodiments of the present invention provide methods
`and apparatus for RF power delivery for generating thermal
`plasmas.
`Embodiments of the present invention provide methods
`and apparatus for RF power delivery for generating non
`thermal plasmas.
`Embodiments of the present invention provide methods
`and apparatus for RF power delivery for promoting chemical
`reactions.
`Embodiments of the present invention provide methods
`and apparatus for RF power delivery for generating plasmas
`for Semiconductor device fabrication StepS. Such as etching,
`deposition, cleaning, doping, oxidation, drying, photoresist
`Stripping, parts cleaning, reaction chamber cleaning, and
`annealing.
`Embodiments of the present invention provide methods
`and apparatus for removal of refractory compounds from
`waste Streams. Refractory compounds include compounds
`that show a high degree of Stability with respect to tempera
`ture and reactivity and are difficult to decompose.
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`8
`Embodiments of the present invention provide new and
`useful methods and apparatus for the destruction of refrac
`tory compounds Such as perfluorocompounds, Such as car
`bon fluorides, carbon tetrafluoride, nitrogen triflouride, and
`Sulfur hexafluoride by reactions facilitated by a plasma.
`Embodiments of the present invention provide methods
`and apparatus for gas waste treatment using a non-thermal
`plasma generated by RF power.
`Embodiments of the present invention provide methods
`and apparatus that are Suitable for processing waste Streams
`emanating from an individual Semiconductor process tool
`and that can become an integral part of the Semiconductor
`device fabrication process.
`An advantage of embodiments of the present invention is
`the ability to provide an economical apparatus and method
`for the destruction of refractory compounds contained in
`gaseous waste Streams.
`Another advantage of embodiments of the present inven
`tion is the ability to provide waste treatment of undiluted off
`gases from individual Semiconductor device fabrication
`tools. Embodiments of the present invention can be made
`compact enough to be integrated into and attached directly
`to one or more than one wafer processing tools.
`The above and still further features and advantages of the
`present invention will become apparent upon consideration
`of the following detailed descriptions of Specific embodi
`ments thereof, especially when taken in conjunction with the
`accompanying drawings.
`
`DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a schematic block diagram of a first embodiment
`of the present invention.
`FIG. 2 is a Schematic block diagram of a Second embodi
`ment of the present invention.
`FIG. 3 is a schematic block diagram of a third embodi
`ment of the present invention.
`FIG. 4 is a schematic block diagram of a fourth embodi
`ment of the present invention.
`FIG. 5 is a schematic block diagram of a fifth embodiment
`of the present invention.
`FIG. 6 is a schematic block diagram of a sixth embodi
`ment of the present invention.
`
`DESCRIPTION
`
`Reference is now made to FIG. 1 wherein there is
`illustrated an RF power processor 20 Such as a plasma
`chamber, a vacuum processing plasma chamber, a plasma
`reactor, or an RF induction heater. The RF power processor
`20 typically operates with a load capable of absorbing RF
`power and using the RF power for a proceSS operation.
`Typical RF power operations and the characteristics of
`appropriate loads are well known in the art. A variable
`frequency RF power delivery System 22 is arranged So as to
`deliver RF power to the RF power processor 20. The RF
`power delivery System 22 is capable of receiving an input of
`electric power from an electric power Source. Typically, the
`electric power source is either DC or slow AC electric
`power. The power Source is capable of providing electric
`power for at least one current and Voltage combination and
`may be capable of providing electric power over a range