`U.S. Patent No. 6,853,142
`
`
`References cited herein:
` U.S. Pat. No. 6,853,142 (“’142 Patent”)
`
` U.S. Pat. No. 6,413,382 (“Wang”)
`
` U.S. Pat. No. 6,190,512 (“Lantsman”)
`
` A. A. Kudryavtsev, et al, Ionization relaxation in a plasma produced by a pulsed inert-gas
`discharge, Sov. Phys. Tech. Phys. 28(1), January 1983 (“Kudryavtsev”)
`
`
`
`‘142 Claims 2 and 11
`
`Wang in view of Lantsman and Kudryavtsev
`
`[1pre.] An apparatus for
`generating a strongly-ionized
`plasma in a chamber, the
`apparatus comprising:
`
`[1a.] an ionization source that
`generates a weakly-ionized
`plasma from a feed gas, the
`weakly-ionized plasma reducing
`the probability of developing an
`electrical breakdown condition in
`the chamber;
`
`ActiveUS 122602266v.1
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`The combination of Wang and Lantsman discloses an
`apparatus for generating a strongly-ionized plasma in a
`chamber.
`
`Wang at 7:19-25 (“Preferably, the peak power PP is at
`least 10 times the background power PB, more preferably
`at least 100 times, and most preferably 1000 times to
`achieve the greatest effect of the invention. A background
`power PB of 1kW will typically be sufficient to support a
`plasma with the torpedo magnetron and a 200 mm wafer
`although with little if any actual sputter deposition.”)
`
`Wang at 7:31-39 (“In one mode of operating the reactor,
`during the background period, little or no target sputtering
`is expected. The SIP reactor is advantageous for a low-
`power, low-pressure background period since the small
`rotating SIP magnetron can maintain a plasma at lower
`power and lower pressure than can a larger stationary
`magnetron. However, it is possible to combine highly
`ionized sputtering during the pulses with significant
`neutral sputtering during the background period.”)
`
`Wang at 7:28-30 (“ the application of the high peak power
`PP instead quickly causes the already existing plasma to
`spread and increases the density of the plasma”)
`
`The combination of Wang and Lantsman discloses an
`ionization source that generates a weakly-ionized plasma
`from a feed gas, the weakly-ionized plasma reducing the
`probability of developing an electrical breakdown
`condition in the chamber.
`
`Wang at Fig. 7
`
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`RENESAS 1124
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`EXHIBIT D.11
`U.S. Patent No. 6,853,142
`
`‘142 Claims 2 and 11
`
`Wang in view of Lantsman and Kudryavtsev
`
`
`
`Wang at 4:5-6 (“A sputter working gas such as argon is
`supplied from a gas source 32….”)
`
`Wang at 4:20-21 (“… a reactive gas, for example nitrogen
`is supplied to the processing space 22….”)
`
`Wang at 7:17-31 (“The background power level PB is
`chosen to exceed the minimum power necessary to
`support a plasma... [T]he application of the high peak
`power PP quickly causes the already existing plasma to
`spread and increases the density of the plasma.”)
`
`Wang at 7:19-25 (“Preferably, the peak power PP is at
`least 10 times the background power PB … and most
`preferably 1000 times to achieve the greatest effect of the
`invention. A background power PB of 1 kW [causes] little
`if any actual sputter deposition.”
`
`Wang at 4:23-31 (“…thus creating a region 42 of a high-
`density plasma (HDP)…”)
`
`Wang at 7:3-49 (“Plasma ignition, particularly in plasma
`sputter reactors, has a tendency to generate particles
`during the initial arcing, which may dislodge large
`particles from the target or chamber… The initial plasma
`ignition needs be performed only once and at much lower
`power levels so that particulates produced by arcing are
`much reduced.”)
`
`Wang at 7:25-28 (“As a result, once the plasma has been
`ignited at the beginning of sputtering prior to the
`illustrated waveform, no more plasma ignition occurs.”).
`
`Wang at 7:58-61 (“… DC power supply 100 is connected
`to the target 14 … and supplies an essentially constant
`negative voltage to the target 14 corresponding to the
`background power PB.”)
`
`Wang at 7:22-23 (“A background power PB of 1 kW will
`typically be sufficient to support a plasma…”)
`The combination of Wang and Lantsman discloses a
`power supply that supplies power to the weakly-ionized
`plasma though an electrical pulse applied across the
`weakly-ionized plasma, the electrical pulse having a
`
`[1b.] a power supply that supplies
`power to the weakly-ionized
`plasma though an electrical pulse
`applied across the weakly-ionized
`
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`EXHIBIT D.11
`U.S. Patent No. 6,853,142
`
`‘142 Claims 2 and 11
`
`Wang in view of Lantsman and Kudryavtsev
`
`
`
`plasma, the electrical pulse
`having a magnitude and a rise-
`time that is sufficient to increase
`the density of the weakly-ionized
`plasma to generate a strongly-
`ionized plasma; and
`
`[1c.] a gas line that supplies feed
`gas to the strongly-ionized
`plasma, the feed gas diffusing the
`strongly-ionized plasma, thereby
`allowing additional power from
`the pulsed power supply to be
`absorbed by the strongly-ionized
`plasma.
`
`magnitude and a rise-time that is sufficient to increase the
`density of the weakly-ionized plasma to generate a
`strongly-ionized plasma.
`
`Wang at Fig. 7
`
`Wang at 7:61-62 (“The pulsed DC power supply 80
`produces a train of negative voltage pulses.”)
`
`Wang at 7:19-25 (“Preferably, the peak power level PP is
`at least 10 times the background power level PB, … most
`preferably 1000 times to achieve the greatest effects of the
`invention. A background power PB of 1 kW will typically
`be sufficient…”)
`
`Wang at 7:28-30 (“… the application of the high peak
`power PP instead quickly causes the already existing
`plasma to spread and increases the density of the
`plasma.”).
`
`Wang at 7:36-39 (“However, it is possible to combine
`highly ionized sputtering during the pulses with
`significant neutral sputtering during the background
`period.”)
`
`Wang at 5:23-27 (“[The pulse’s] exact shape depends on
`the design of the pulsed DC power supply 80, and
`significant rise times and fall times are expected.”)
`
`See evidence cited in limitation [1pre] of claim 1.
`
`The combination of Wang and Lantsman discloses a gas
`line that supplies feed gas to the strongly-ionized plasma,
`the feed gas diffusing the strongly-ionized plasma, thereby
`allowing additional power from the pulsed power supply
`to be absorbed by the strongly-ionized plasma.
`
`Wang at Fig. 1
`
`Wang at 4:5-6 (“A sputter working gas such as argon is
`supplied from a gas source 32 through a mass flow
`controller 34 to a region in back of the grounded shield
`24.”)
`
`Wang at 4:8-10 (“The gas flows into the processing region
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`EXHIBIT D.11
`U.S. Patent No. 6,853,142
`
`‘142 Claims 2 and 11
`
`Wang in view of Lantsman and Kudryavtsev
`
`
`
`22 through a gap formed between the pedestal 18, the
`grounded shield 24, and a clamp ring or plasma focus ring
`36 surrounding the periphery of the wafer 20.”)
`
`Wang at 4:51-55 (“A computerized controller 58 controls
`the … mass flow controller 34, as illustrated….”)
`
`Lantsman at 2:48-51 (“This secondary power supply ‘pre-
`ignites’ the plasma so that when the primary power supply
`is applied, the system smoothly transitions to final plasma
`development and deposition.”)
`
`One of ordinary skill would have been motivated to
`combine Wang and Lantsman. Lantsman is directed to
`sputtering using a plasma. So is Wang. See Wang at Title
`(“Pulsed sputtering with a small rotating magnetron”);
`3:20-21 (“[A] high plasma density is achieved adjacent to
`the magnetron during the pulse.”). Also, Lantsman uses
`two power supplies, one for pre-ionization and one for
`deposition. So does Wang. See Wang at Fig. 7 [showing
`pulsed supply 80 and constant supply 100]
`
`Lantsman generates a plasma without arcing. So does
`Wang. Wang at 7:3-49 (“Plasma ignition, particularly in
`plasma sputter reactors, has a tendency to generate
`particles during the initial arcing, …. The initial plasma
`ignition needs be performed only once and at much lower
`power levels so that particulates produced by arcing are
`much reduced.”)
`
`Summarizing, Wang and Lantsman relate to the same
`application. Further, one of ordinary skill would have
`been motivated to use Lantsman’s continuous gas flow in
`Wang so as to maintain a desired pressure in the chamber.
`Also, use of Lantsman’s continuous gas flow in Wang
`would have worked well with Wang’s mass flow
`controller 34 and would have been a combination of old
`elements in which each element behaved as expected.
`Finally, such a continuous flow of gas in Wang would
`diffuse the strongly-ionized plasma and allow additional
`power to be absorbed by the plasma as required by claim
`1.
`
`2. The apparatus of claim 1
`wherein the power supply applies
`
`The combination of Wang, Lantsman, and Kudryavtsev
`disclose the power supply applies the electrical pulse
`
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`EXHIBIT D.11
`U.S. Patent No. 6,853,142
`
`‘142 Claims 2 and 11
`
`Wang in view of Lantsman and Kudryavtsev
`
`
`
`the electrical pulse across the
`weakly-ionized plasma to excite
`atoms in the weakly-ionized
`plasma and to generate secondary
`electrons, the secondary electrons
`ionizing the excited atoms,
`thereby creating the strongly-
`ionized plasma.
`
`across the weakly-ionized plasma to excite atoms in the
`weakly-ionized plasma and to generate secondary
`electrons, the secondary electrons ionizing the excited
`atoms, thereby creating the strongly-ionized plasma.
`
`See evidence cited in claim 1
`
`‘142 Patent at 1:41-43 (“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.”)
`
`‘142 Patent at 1:37-40 (“The plasma is replenished by
`electron-ion pairs formed by the collision of neutral
`molecules with secondary electrons generated at the target
`surface.”)
`
`Wang at Fig. 7
`
`Wang at 7:61-62 (“The pulsed DC power supply 80
`produces a train of negative voltage pulses.”)
`
`Wang at 7:19-25 (“Preferably, the peak power level PP is
`at least 10 times the background power level PB, … most
`preferably 1000 times to achieve the greatest effects of the
`invention. A background power PB of 1 kW will typically
`be sufficient…”)
`
`Wang at 7:36-39 (“However, it is possible to combine
`highly ionized sputtering during the pulses with
`significant neutral sputtering during the background
`period.”)
`
`Kudryavtsev at Figs. 1, 6
`
`Kudryavtsev at 34, right col, ¶ 4 (“[s]ince the effects
`studied in this work are characteristic of ionization
`whenever a field is suddenly applied to a weakly ionized
`gas, they must be allowed for when studying emission
`mechanisms in pulsed gas lasers, gas breakdown, laser
`sparks, etc.”)
`
`Kudryavtsev at 31, right col, ¶ 6 (“For nearly stationary n2
`[excited atom density] values … there is an explosive
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`EXHIBIT D.11
`U.S. Patent No. 6,853,142
`
`‘142 Claims 2 and 11
`
`Wang in view of Lantsman and Kudryavtsev
`
`
`
`increase in ne [plasma density]. The subsequent increase
`in ne then reaches its maximum value, equal to the rate of
`excitation [equation omitted], which is several orders of
`magnitude greater than the ionization rate during the
`initial stage.”)
`
`Kudryavtsev at Abstract (“in a pulsed inert-gas discharge
`plasma at moderate pressures… [i]t is shown that the
`electron density increases explosively in time due to
`accumulation of atoms in the lowest excited states.”)
`
`Kudryavtsev at Equation 1
`
`Kudryavtsev at 30, right col, last ¶ (“n2, and ne are the
`atomic densities in the … first excited states and the
`electron density, respectively … 2e [is] the rate
`coefficient[]….”)
`
`See evidence cited in [21pre] of claim 21.
`
`If one of ordinary skill, applying Wang’s power levels did
`not experience Kudryavtsev’s “explosive increase” in
`plasma density, it would have been obvious to adjust the
`operating parameters, e.g., increase the pulse length and/or
`pressure, so as to trigger Kudryavtsev’s fast stage of
`ionization. One of ordinary skill would have been
`motivated to use Kudryavtsev’s fast stage of ionization in
`Wang so as to increase plasma density and thereby
`increase the sputtering rate. Also, Kudryavtsev’s fast
`stage would reduce the time required to reach a given
`plasma density in Wang, thus reducing the time required
`for a sputtering process. Further, use of Kudryavtsev’s
`fast stage in Wang would have been a combination of old
`elements that yielded predictable results.
`
`Kudryavtsev states, “[s]ince the effects studied in this
`work are characteristic of ionization whenever a field is
`suddenly applied to a weakly ionized gas, they must be
`allowed for when studying emission mechanisms in
`pulsed gas lasers, gas breakdown, laser sparks, etc.”
`Kudryavtsev at 34, right col, ¶ 4. Because Wang applies
`voltage pulses that “suddenly generate an electric field,”
`one of ordinary skill reading Wang would have been
`motivated to consider Kudryavtsev and to use
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`EXHIBIT D.11
`U.S. Patent No. 6,853,142
`
`‘142 Claims 2 and 11
`
`Wang in view of Lantsman and Kudryavtsev
`
`Kudryavtsev’s fast stage in Wang.
`
`[10pre.] A method for generating
`a strongly-ionized plasma in a
`chamber, the method comprising:
`
`The combination of Wang and Lantsman discloses a
`method for generating a strongly-ionized plasma in a
`chamber.
`
`[10a.] ionizing a feed gas to form
`a weakly-ionized plasma that
`reduces the probability of
`developing an electrical
`breakdown condition in the
`chamber;
`
`[10b.] supplying power to the
`weakly-ionized plasma by
`applying an electrical pulse across
`the weakly-ionized plasma, the
`electrical pulse having a
`magnitude and a rise-time that is
`sufficient to increase the density
`of the weakly-ionized plasma to
`generate a strongly-ionized
`plasma; and
`
`[10c.] diffusing the strongly-
`ionized plasma with additional
`feed gas thereby allowing the
`strongly-ionized plasma to absorb
`additional energy from the power
`supply.
`
`11. The method of claim 10
`wherein the applying the
`electrical pulse across the weakly-
`ionized plasma excites atoms in
`the weakly-ionized plasma and
`generates secondary electrons, the
`secondary electrons ionizing the
`excited atoms, thereby creating a
`strongly-ionized plasma.
`
`See evidence cited in claim 1 preamble.
`
`The combination of Wang and Lantsman discloses
`ionizing a feed gas to form a weakly-ionized plasma that
`reduces the probability of developing an electrical
`breakdown condition in the chamber.
`
`See evidence cited limitation [1a] in claim 1.
`
`The combination of Wang and Lantsman discloses
`supplying power to the weakly-ionized plasma by
`applying an electrical pulse across the weakly-ionized
`plasma, the electrical pulse having a magnitude and a rise-
`time that is sufficient to increase the density of the
`weakly-ionized plasma to generate a strongly-ionized
`plasma.
`
`See evidence cited in limitation [1b] in claim 1.
`
`The combination of Wang and Lantsman discloses
`diffusing the strongly-ionized plasma with additional feed
`gas thereby allowing the strongly-ionized plasma to
`absorb additional energy from the power supply.
`
`See evidence cited in limitation [1c] in claim 1.
`
`The combination of Wang, Lantsman, and Kudryavtsev
`disclose the applying the electrical pulse across the
`weakly-ionized plasma excites atoms in the weakly-
`ionized plasma and generates secondary electrons, the
`secondary electrons ionizing the excited atoms, thereby
`creating a strongly-ionized plasma.
`
`See evidence cited in claim 10.
`
`See evidence cited in claim 2.
`
`
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