`U.S. Patent No. 7,604,716
`
`References cited herein:
`
`(cid:120) U.S. Patent No. 7,604,716 (“‘716 Patent”)
`
`(cid:120) U.S. Pat. No. 6,413,382 (“Wang”)
`
`(cid:120) U.S. Pat. No. 6,190,512 (“Lantsman”)
`
`Claims 12-13
`
`1. An apparatus for
`generating a strongly-
`ionized plasma, the
`apparatus comprising:
`
`a. an ionization source
`that generates a
`weakly-ionized
`plasma from a feed
`gas contained in a
`chamber, the weakly-
`ionized plasma
`substantially
`eliminating the
`probability of
`developing an
`electrical breakdown
`condition in the
`chamber; and
`
`Wang in view of Lantsman
`
`Wang discloses an apparatus for generating a strongly-ionized plasma.
`
`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 7:28-30 (“ the application of the high peak power PP instead
`quickly causes the already existing plasma to spread and increases the
`density of the plasma”) (emphasis added).
`
`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 discloses an ionization source that generates a weakly-ionized
`plasma from a feed gas contained in a chamber, the weakly-ionized
`plasma substantially eliminating the probability of developing an
`electrical breakdown condition in the chamber.
`
`Wang at Fig. 7
`
`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
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`INTEL 1117
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`EXHIBIT B.11
`U.S. Patent No. 7,604,716
`
`Claims 12-13
`
`Wang in view of Lantsman
`
`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…”)
`
`Wang discloses a power supply that supplies power to the weakly-
`ionized plasma though an electrical pulse that is applied across the
`weakly-ionized plasma, the electrical pulse having at least one of a
`magnitude and a rise-time that is sufficient to transform the weakly-
`ionized plasma to a strongly-ionized plasma without developing an
`electrical breakdown condition in the chamber.
`
`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…”)
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`b. a power supply that
`supplies power to the
`weakly-ionized
`plasma though an
`electrical pulse that is
`applied across the
`weakly-ionized
`plasma, the electrical
`pulse having at least
`one of a magnitude
`and a rise-time that is
`sufficient to transform
`the weakly-ionized
`plasma to a strongly-
`ionized plasma
`without developing an
`electrical breakdown
`
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`Claims 12-13
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`condition in the
`chamber.
`
`12. The apparatus of
`claim 1 further
`comprising a gas line
`that is coupled to the
`chamber, the gas line
`supplying feed gas to
`the strongly-ionized
`plasma that transports
`the strongly-ionized
`plasma by a rapid
`volume exchange.
`
`EXHIBIT B.11
`U.S. Patent No. 7,604,716
`
`Wang in view of Lantsman
`
`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.”)
`
`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.”).
`
`See evidence cited in claim 1 preamble.
`The combination of Wang with Lantsman discloses a gas line that is
`coupled to the chamber, the gas line supplying feed gas to the strongly-
`ionized plasma that transports the strongly-ionized plasma by a rapid
`volume exchange.
`
`It would have been obvious to one of ordinary skill to continue to add
`the feed gas in Wang during production of the strongly-ionized plasma
`(i.e., during application of the peak power pulses PP). Such addition of
`the feed gas would transport the strongly-ionized plasma by a rapid
`volume exchange as recited in claim 12.
`
`Lantsman at 3:9-13 (“[A]t the beginning of processing, this switch is
`closed and gas is introduced into the chamber. When the plasma
`process is completed, the gas flow is stopped….”).
`
`Lantsman at 4:36-38 (“To end processing, primary supply 10 is
`disabled, reducing the plasma current and deposition on the wafer.
`Then, gas flow is terminated….”).
`
`Lantsman at Fig. 6:
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`EXHIBIT B.11
`U.S. Patent No. 7,604,716
`
`Claims 12-13
`
`Wang in view of Lantsman
`
`Lantsman at 5:39-42 (“Sometime thereafter, gas flow is initiated and the
`gas flow and pressure (trace 48) begin to ramp upwards toward normal
`processing levels.”).
`
`Lantsman at 5:42-45 (“After a delay time (54), a normal pressure and
`flow rate are achieved, and primary supply 10 is enabled, causing a
`ramp increase in the power produced by the primary supply (trace
`52).”).
`
`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.”).
`
`It would have been obvious to one of ordinary skill to continue to apply
`the feed gas during Wang’s background and peak power, PB and PP, as
`taught by Lantsman. Such a continuous introduction of feed gas
`balances gas withdrawn by Wang’s vacuum system 38 so as to maintain
`a desired pressure. Wang at 4:11-12 (“A vacuum system 38 pumps the
`chamber through a pumping port 40.”). Such a continuous flow of gas
`would transport Wang’s strongly-ionized plasma by a rapid volume
`exchange.
`
`One of ordinary skill would have been motivated to combine Wang and
`Lantsman. Both Wang and Lantsman are directed to sputtering using
`plasma. Wang at title (“Pulsed sputtering with small rotating
`magnetron”); see also Lantsman at 1:6-8 (“This invention relates to
`reduction of device damage in plasma processes, including DC
`(magnetron or non-magnetron) sputtering, and RF sputtering.”). Both
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`EXHIBIT B.11
`U.S. Patent No. 7,604,716
`
`Claims 12-13
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`Wang in view of Lantsman
`
`references also relate to sputtering systems that use two power supplies,
`one for pre-ionization and one for deposition. See Lantsman at 4:45-47
`(“[T]he secondary [power] supply 32 is used to pre-ignite the plasma,
`whereas the primary [power] supply 10 is used to generate
`deposition.”); See Wang at Fig. 7. (showing the variable supply 100 and
`the pulsed DC supply 80”).
`
`Both Wang and Lantsman are concerned with generating plasma while
`avoiding arcing. See Lantsman (“Furthermore, arcing which can be
`produced by overvoltages can cause local overheating of the target,
`leading to evaporation or flaking of target material into the processing
`chamber and causing substrate particle contamination and device
`damage…. Thus, it is advantageous to avoid voltage spikes during
`processing whenever possible.”)
`
`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.
`Finally, use of Lantsman’s continuous gas flow in Wang would have
`been a combination of old elements in which each element behaved as
`expected.
`
`The combination of Wang with Lantsman discloses the gas volume
`exchange permits additional power to be absorbed by the strongly-
`ionized plasma.
`
`See evidence cited in claim 12.
`
`It would have been obvious to one of ordinary skill to continue to add
`the feed gas in Wang during production of the strongly-ionized plasma.
`Such addition of the feed gas would have both transported the strongly-
`ionized plasma by rapid volume exchange and allowed additional power
`from Wang’s repeating voltage pulses to be absorbed by the strongly-
`ionized plasma.
`
`13. The apparatus of
`claim 12 wherein the
`gas volume exchange
`permits additional
`power to be absorbed
`by the strongly-
`ionized plasma.
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