UNITED STATES PATENT AND TRADEMARK OFFICE
`
`UNITED STATES DEPARTMENT OF COMMERCE
`United States Patent and Trademark Office
`Address: COMMISSIONER FOR PATENTS
`P.O. Box 1450
`Alexandria, Virginia 22313-1450
`www.uspto.gov
`
`APPLICATION NO.
`
`F ING DATE
`
`FIRST NAMED INVENTOR
`
`ATTORNEY DOCKET NO.
`
`CONF {MATION NO.
`
`14/510,959
`
`10/09/2014
`
`Donald K. Smith
`
`EGQ—005CP3C3
`
`5575
`
`42532
`7590
`PROSKAUER ROSE LLP
`ONE INTERNATIONAL PLACE
`BOSTON, MA 02110
`
`11/12/2014
`
`MCCORMACK, JASON L
`
`2881
`
`11/12/2014
`
`ELECTRONIC
`
`Please find below and/or attached an Office communication concerning this application or proceeding.
`
`The time period for reply, if any, is set in the attached communication.
`
`Notice of the Office communication was sent electronically on aboVe—indicated "Notification Date" to the
`following e—mail address(es):
`
`D0cketingPatentB0st0n @pr0skauer.c0m
`oandrews @pr0skauer.c0m
`
`PTOL—90A (Rev. 04/07)
`
`1
`
`ASML 1008
`
`

`
`Application No.
`14/510,959
`
`App|icant(s)
`SMITH, DONALD K.
`
`Office Action Summary
`
`AIA (First lnventorto File)
`Art unit
`Examiner
`f\,*f‘)‘”5
`2881
`JASON MCCORMACK
`-- The MAILING DA TE of this communication appears on the cover sheet with the correspondence address --
`Period for Reply
`
`A SHORTENED STATUTORY PERIOD FOR REPLY IS SET TO EXPIRE § MONTHS FROM THE MAILING DATE OF
`THIS COMMUNICATION.
`Extensions of time may be available under the provisions of 37 CFR 1.136(a).
`after SIX (6) MONTHS from the mailing date of this communication.
`If NO period for reply is specified above, the maximum statutory period will apply and will expire SIX (6) MONTHS from the mailing date of this communication.
`Failure to reply within the set or extended period for reply will, by statute, cause the application to become ABANDONED (35 U.S.C. § 133).
`Any reply received by the Office later than three months after the mailing date of this communication, even if timely filed, may reduce any
`earned patent term adjustment. See 37 CFR 1.704(b).
`
`In no event, however, may a reply be timely filed
`
`—
`—
`
`Status
`
`1)IXI Responsive to communication(s) filed on 10/9/2014.
`I:I A declaration(s)/affidavit(s) under 37 CFR 1.130(b) was/were filed on
`
`2b)IXI This action is non—final.
`2a)I:I This action is FINAL.
`3)I:I An election was made by the applicant in response to a restriction requirement set forth during the interview on
`
`; the restriction requirement and election have been incorporated into this action.
`
`4)I:I Since this application is in condition for allowance except for formal matters, prosecution as to the merits is
`closed in accordance with the practice under Ex parte Quayle, 1935 C.D. 11, 453 O.G. 213.
`
`Disposition of Claims*
`5)IZ| Claim(s)1—:.3‘0is/are pending in the application.
`5a) Of the above claim(s) j is/are withdrawn from consideration.
`6)I:I Claim(s) j is/are allowed.
`7)IXI Claim(s)1—:.3‘0is/are rejected.
`8)I:I Claim(s) _ is/are objected to.
`
`_ are subject to restriction and/or election requirement.
`I
`* If any claims have been determined allowable, you may be eligible to benefit from the Patent Prosecution Highway program at a
`
`participating intellectual property office for the corresponding application. For more information, please see
`if/index.‘s
`
`
`
`://\wlIw.uspto. ov/ atents/init events/'
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`, orsend an inquiry to PPI--lfeedback@usjgjtoxzov.
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`htt
`
`Application Papers
`
`10)I:I The specification is objected to by the Examiner.
`11)|:I The drawing(s) filed on _ is/are: a)I:I accepted or b)I:I objected to by the Examiner.
`Applicant may not request that any objection to the drawing(s) be held in abeyance. See 37 CFR 1.85(a).
`
`Replacement drawing sheet(s) including the correction is required if the drawing(s) is objected to. See 37 CFR 1.121 (d).
`
`Priority under 35 U.S.C. § 119
`12)I:I Acknowledgment is made of a claim for foreign priority under 35 U.S.C. §119(a)-(d) or (f).
`Certified copies:
`
`b)I:I Some** c)I:I None of the:
`a)I:I All
`1.I:I Certified copies of the priority documents have been received.
`2.I:I Certified copies of the priority documents have been received in Application No. j
`3.I:| Copies of the certified copies of the priority documents have been received in this National Stage
`
`application from the International Bureau (PCT Rule 17.2(a)).
`** See the attached detailed Office action for a list of the certified copies not received.
`
`Attach ment(s)
`
`1) X Notice of References Cited (PTO-892)
`3) D jntervjew summary (pTo-413)
`_
`_
`Paper No(s)/Mail Date. j
`2) X Information Disclosure Statement(s) (PTO/SB/08a and/or PTO/SB/08b)
`Paper No(s)/Mail Date 10/9/2014. 4) I:I Other‘ :-
`
`U.S. Patent and Trademark Office
`PTOL—326 (Rev. 11-13)
`
`Part of Paper No./Mail Date 20141030
`
`Office Action Summary
`
`

`
`Application/Control Number: 14/510,959
`
`Page 2
`
`Art Unit: 2881
`
`1.
`
`The present application is being examined under the pre-AIA first to invent
`
`provisions.
`
`DETAILED ACTION
`
`Specification
`
`2.
`
`The title of the invention is not descriptive. A new title is required that is clearly
`
`indicative of the invention to which the claims are directed.
`
`The following title is suggested: Light Source for Generating Light from a Laser-
`
`Sustained Plasma in an Above-Atmospheric Pressure Chamber.
`
`Claim Rejections - 35 USC § 102
`
`3.
`
`The following is a quotation of the appropriate paragraphs of pre-AIA 35 U.S.C.
`
`102 that form the basis for the rejections under this section made in this Office action:
`
`A person shall be entitled to a patent unless —
`
`(b) the invention was patented or described in a printed publication in this or a foreign country
`or in public use or on sale in this country, more than one year prior to the date of application
`for patent in the United States.
`
`4.
`
`Claim 15 is rejected under pre-AIA 35 U.S.C. 102(b) as being anticipated by
`
`Cross et al. U.S. Patent No. 4,780,608.
`
`Regarding claim 15, Cross discloses a light source comprising a pressurized
`
`chamber in which a laser sustained plasma emits plasma-generated light produced by
`
`the laser sustained plasma by providing at least substantially continuous laser energy to
`
`an ionized medium within the chamber and maintaining the chamber at a pressure that
`
`is greater than atmospheric pressure “free-standing continuous discharges have been
`
`produced by focusing the output of a sufficiently powerful cw-CO2 laser into inert gases,
`
`

`
`Application/Control Number: 14/510,959
`
`Page 3
`
`Art Unit: 2881
`
`molecular gases and mixtures thereof at atmospheric pressures or above... Although
`
`cw-laser radiation can maintain the continuous optical discharge, the output power of
`
`such light sources is generally insufficient to initiate the discharge. Consequently, such
`
`plasmas can be initiated using conventional electrode sparks or by the spark produced
`
`by a focused laser pulse superimposed on the focal volume of the cw-laser beam used
`
`to maintain the plasma” [col. 1; lines 30-52].
`
`Claim Rejections - 35 USC § 103
`
`The following is a quotation of pre-AIA 35 U.S.C. 103(a) which forms the basis for all
`
`obviousness rejections set forth in this Office action:
`
`(a) A patent may not be obtained though the invention is not identically disclosed or described
`as set forth in section 102 of this title, if the differences between the subject matter sought to
`be patented 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 having ordinary skill in the art to which
`said subject matter pertains. Patentability shall not be negatived by the manner in which the
`invention was made.
`
`5.
`
`Claims 1, 2, 3, 4, 7, 8, 9, 10, 13, and 14 are rejected under pre-AIA 35 U.S.C.
`
`103(a) as being unpatentable over Kane et al. U.S. Patent No. 6,541,924 in view of
`
`Cross et al. U.S. Patent No. 4,780,608.
`
`Regarding claim 1, Kane discloses a light source “The embodiments of the
`
`invention provide methods of and systems for generating light usually ultraviolet light or
`
`vacuum ultraviolet light“ [col. 6; lines 14-16] comprising: a pressurized chamber “The
`
`lamp comprises a discharge chamber” [Abstract] having a gas at a pressure greater
`
`than atmospheric pressure "Typically the gas pressure in the discharge chamber is in
`
`

`
`Application/Control Number: 14/510,959
`
`Page 4
`
`Art Unit: 2881
`
`the range of from about 1.001 atmospheres-3 atmospheres” [col. 7; lines 13-15]; an
`
`ignition source for ionizing a gas “a discharge gas in said chamber” [col. 1; line 41]
`
`within the chamber “two electrodes disposed with respect to the chamber for
`
`discharging electrical energy therebetween” [Abstract]. Kane discloses the claimed
`
`invention except that while Kane discloses that it is known to use a laser for providing
`
`energy to an ionized gas to sustain a plasma “More commonly, laser-based sources of
`
`high-peak power UV radiation are used for such applications” [col. 8; lines 6-8], there is
`
`no explicit disclosure of at least one laser for providing energy to the ionized gas to
`
`sustain a plasma within the chamber to produce a plasma-generated light.
`
`Cross discloses that “free—standing continuous discharges have been produced
`
`by focusing the output of a sufficiently powerful cw-CO2 laser into inert gases, molecular
`
`gases and mixtures thereof at atmospheric pressures or above... Although cw-laser
`
`radiation can maintain the continuous optical discharge, the output power of such light
`
`sources is generally insufficient to initiate the discharge. Consequently, such plasmas
`
`can be initiated using conventional electrode sparks or by the spark produced by a
`
`focused laser pulse superimposed on the focal volume of the cw-laser beam used to
`
`maintain the plasma” [col. 1; lines 30-52].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Kane and Cross in order to maintain the light emitted
`
`from a plasma for a desired amount of time after the plasma is initially produced by an
`
`electrode discharge.
`
`

`
`Application/Control Number: 14/510,959
`
`Page 5
`
`Art Unit: 2881
`
`Regarding claim 2, Kane discloses the claimed invention but while Kane
`
`discloses that it is known to use a laser for providing energy to an ionized gas to sustain
`
`a plasma “More commonly, laser—based sources of high-peak power UV radiation are
`
`used for such applications” [col. 8; lines 6-8], there is no explicit disclosure of an optical
`
`element for such a laser.
`
`Cross discloses that “free—standing continuous discharges have been produced
`
`by focusing the output of a sufficiently powerful cw-CO2 laser into inert gases, molecular
`
`gases and mixtures thereof at atmospheric pressures or above... Although cw-laser
`
`radiation can maintain the continuous optical discharge, the output power of such light
`
`sources is generally insufficient to initiate the discharge. Consequently, such plasmas
`
`can be initiated using conventional electrode sparks or by the spark produced by a
`
`focused laser pulse superimposed on the focal volume of the cw-laser beam used to
`
`maintain the plasma” [col. 1; lines 30-52] and discloses that a lens (12) may focus laser
`
`(16) towards region (14) “in which a continuous optical discharge is to be generated”
`
`[col. 5; lines 58-59].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Kane and Cross in order to appropriately direct a
`
`laser beam towards a plasma site so that it may be utilized in sustaining the plasma
`
`over a desired amount of time.
`
`Regarding claim 3, Kane discloses the claimed invention but while Kane
`
`discloses that it is known to use a laser for providing energy to an ionized gas to sustain
`
`

`
`Application/Control Number: 14/510,959
`
`Page 6
`
`Art Unit: 2881
`
`a plasma “More commonly, laser—based sources of high-peak power UV radiation are
`
`used for such applications” [col. 8; lines 6-8], there is no explicit disclosure of an optical
`
`element for such a laser.
`
`Cross discloses that “free—standing continuous discharges have been produced
`
`by focusing the output of a sufficiently powerful cw—CO2 laser into inert gases, molecular
`
`gases and mixtures thereof at atmospheric pressures or above... Although cw-laser
`
`radiation can maintain the continuous optical discharge, the output power of such light
`
`sources is generally insufficient to initiate the discharge. Consequently, such plasmas
`
`can be initiated using conventional electrode sparks or by the spark produced by a
`
`focused laser pulse superimposed on the focal volume of the cw-laser beam used to
`
`maintain the plasma” [col. 1; lines 30-52] and discloses that a lens (12) may focus laser
`
`(16) towards region (14) “in which a continuous optical discharge is to be generated”
`
`[col. 5; lines 58-59].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Kane and Cross in order to appropriately direct a
`
`laser beam towards a plasma site so that it may be utilized in sustaining the plasma
`
`over a desired amount of time.
`
`Regarding claim 4, Kane discloses that “The lamp comprises a discharge
`
`chamber which is at least partially transparent to the incoherent radiation” [Abstract].
`
`

`
`Application/Control Number: 14/510,959
`
`Page 7
`
`Art Unit: 2881
`
`Regarding claim 7, Kane discloses the claimed invention except that while Kane
`
`discloses that it is known to use a laser for providing energy to an ionized gas to sustain
`
`a plasma “More commonly, laser—based sources of high-peak power UV radiation are
`
`used for such applications” [col. 8; lines 6-8], there is no explicit disclosure of at least
`
`one laser for providing energy to the ionized gas to sustain a plasma within the chamber
`
`to produce a plasma—generated light.
`
`Cross discloses that “free—standing continuous discharges have been produced
`
`by focusing the output of a sufficiently powerful cw-CO2 laser into inert gases, molecular
`
`gases and mixtures thereof at atmospheric pressures or above... Although cw-laser
`
`radiation can maintain the continuous optical discharge, the output power of such light
`
`sources is generally insufficient to initiate the discharge. Consequently, such plasmas
`
`can be initiated using conventional electrode sparks or by the spark produced by a
`
`focused laser pulse superimposed on the focal volume of the cw-laser beam used to
`
`maintain the plasma” [col. 1; lines 30-52].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Kane and Cross in order to maintain the light emitted
`
`from a plasma for a desired amount of time after the plasma is initially produced by an
`
`electrode discharge.
`
`Regarding claim 8, Kane discloses “The lamp comprises... two electrodes
`
`disposed with respect to the chamber for discharging electrical energy therebetween
`
`whereby, in use, a substantially homogeneous discharge occurs between the two
`
`

`
`Application/Control Number: 14/510,959
`
`Page 8
`
`Art Unit: 2881
`
`electrodes which causes emission of incoherent radiation pulses of high peak power
`
`from the lamp” [Abstract].
`
`Regarding claim 9, Kane discloses an elliptical reflector (illustrated in figure 12)
`
`wherein “The elliptical reflector provides a means to focus the UV/VUV output from the
`
`lamp to a focal spot at the sample surface to achieve a higher illumination fluence
`
`(J/cm.sup.2) or intensity (W/cm.sup.2) than possible by placement of the sample in
`
`close proximity of the lamp” [col. 16; lines 16-20]. The light is then utilized in a tool “a
`
`method of ablating/etching a material by irradiating the material with incoherent
`
`radiation pulses generated by a method of the invention, said pulses being of sufficient
`
`intensity to ablate/etch said surface” [col. 3; lines 11-14].
`
`Regarding claim 10, Kane discloses that the light may be utilized in a process of
`
`lithography “a method of ablating/etching a material by irradiating the material with
`
`incoherent radiation pulses generated by a method of the invention, said pulses being of
`
`sufficient intensity to ablate/etch said surface” [col. 3; lines 11-14].
`
`Regarding claim 13, Kane discloses a method for producing light “The
`
`embodiments of the invention provide methods of and systems for generating light
`
`usually ultraviolet light or vacuum ultraviolet light” [col. 6; lines 14-16], comprising:
`
`ionizing, with an ignition source disposed in a pressurized chamber “The lamp
`
`comprises a discharge chamber which is at least partially transparent to the incoherent
`
`

`
`Application/Control Number: 14/510,959
`
`Page 9
`
`Art Unit: 2881
`
`radiation, a discharge gas in the chamber, two electrodes disposed with respect to the
`
`chamber for discharging electrical energy therebetween” [Abstract], a gas “a discharge
`
`gas in said chamber” [col. 1; line 41] having a pressure greater than atmospheric
`
`pressure "Typically the gas pressure in the discharge chamber is in the range of from
`
`about 1.001 atmospheres-3 atmospheres” [col. 7; lines 13-15]. Kane discloses the
`
`claimed invention except that while Kane discloses that it is known to use a laser for
`
`providing energy to an ionized gas to sustain a plasma “More commonly, laser-based
`
`sources of high-peak power UV radiation are used for such applications” [col. 8; lines 6-
`
`8], there is no explicit disclosure of at least one laser for providing energy to the ionized
`
`gas to sustain a plasma within the chamber to produce a plasma-generated light.
`
`Cross discloses that “free—standing continuous discharges have been produced
`
`by focusing the output of a sufficiently powerful cw-CO2 laser into inert gases, molecular
`
`gases and mixtures thereof at atmospheric pressures or above... Although cw-laser
`
`radiation can maintain the continuous optical discharge, the output power of such light
`
`sources is generally insufficient to initiate the discharge. Consequently, such plasmas
`
`can be initiated using conventional electrode sparks or by the spark produced by a
`
`focused laser pulse superimposed on the focal volume of the cw-laser beam used to
`
`maintain the plasma” [col. 1; lines 30-52].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Kane and Cross in order to maintain the light emitted
`
`from a plasma for a desired amount of time after the plasma is initially produced by an
`
`electrode discharge.
`
`

`
`Application/Control Number: 14/510,959
`
`Page 10
`
`Art Unit: 2881
`
`Regarding claim 14, Kane discloses emitting light in the wavelength range “80—
`
`350 nm, more typically 11-320 nm” [col. 7; line 55]. Kane discloses the claimed
`
`invention except that while Kane discloses that it is known to use a laser for providing
`
`energy to an ionized gas to sustain a plasma “More commonly, laser-based sources of
`
`high-peak power UV radiation are used for such applications” [col. 8; lines 6-8], there is
`
`no explicit disclosure of at least one laser for providing energy to the ionized gas to
`
`sustain a plasma within the chamber to produce a plasma-generated light.
`
`Cross discloses that “free—standing continuous discharges have been produced
`
`by focusing the output of a sufficiently powerful cw-CO2 laser into inert gases, molecular
`
`gases and mixtures thereof at atmospheric pressures or above... Although cw-laser
`
`radiation can maintain the continuous optical discharge, the output power of such light
`
`sources is generally insufficient to initiate the discharge. Consequently, such plasmas
`
`can be initiated using conventional electrode sparks or by the spark produced by a
`
`focused laser pulse superimposed on the focal volume of the cw-laser beam used to
`
`maintain the plasma” [col. 1; lines 30-52].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Kane and Cross in order to maintain the light emitted
`
`from a plasma for a desired amount of time after the plasma is initially produced by an
`
`electrode discharge.
`
`

`
`Application/Control Number: 14/510,959
`
`Page 11
`
`Art Unit: 2881
`
`6.
`
`Claim 5 is rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over
`
`Kane et al. U.S. Patent No. 6,541,924 in view of Cross et al. U.S. Patent No. 4,780,608
`
`in further view of Kondo U.S. PGPUB No. 2003/0147499.
`
`Regarding claim 5, Kane discloses that “The lamp comprises a discharge
`
`chamber which is at least partially transparent to the incoherent radiation” [Abstract] but
`
`does not explicitly disclose the material which forms the at least partially transparent
`
`discharge chamber.
`
`Kondo discloses a system for generating light from a plasma [0008] and
`
`discloses “a vacuum chamber 407 made of quartz glass” [0047] since “Quartz glass is
`
`highly transmissive to light in the range of infrared to ultraviolet” [0047].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Kane, Cross, and Kondo in order to utilize a material
`
`which is suitably transparent for allowing the light to permeate from a chamber (which is
`
`maintained at a pressure desirable for the formation of a plasma therein) to a region
`
`outside of the chamber where the light may be utilized in a downstream operation.
`
`7.
`
`Claims 6, 20, 21, 22, 24, 29, and 30 are rejected under pre-AIA 35 U.S.C. 103(a)
`
`as being unpatentable over Kane et al. U.S. Patent No. 6,541,924 in view of Cross et al.
`
`U.S. Patent No. 4,780,608 in further view of Ershov et al. U.S. PGPUB No.
`
`2006/0192152.
`
`

`
`Application/Control Number: 14/510,959
`
`Page 12
`
`Art Unit: 2881
`
`Regarding claim 6, Kane discloses the claimed invention except that there is no
`
`explicit disclosure that the disclosed chamber is sealed.
`
`Ershov discloses that laser window (202) “may be utilized for vacuum sealing the
`
`chamber 26” [0040].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Kane, Cross, and Ershov in order to prevent
`
`undesired changes in the pressure within the plasma chamber which may adversely
`
`affect the formation of the plasma therein.
`
`Regarding claim 20, Kane discloses a light source “The embodiments of the
`
`invention provide methods of and systems for generating light usually ultraviolet light or
`
`vacuum ultraviolet light“ [col. 6; lines 14-16] comprising: a pressurized chamber “The
`
`lamp comprises a discharge chamber” [Abstract] having a gas at a pressure greater
`
`than atmospheric pressure "Typically the gas pressure in the discharge chamber is in
`
`the range of from about 1.001 atmospheres-3 atmospheres” [col. 7; lines 13-15]; an
`
`ignition source for ionizing a gas “a discharge gas in said chamber” [col. 1; line 41]
`
`within the chamber “two electrodes disposed with respect to the chamber for
`
`discharging electrical energy therebetween” [Abstract]. Kane discloses the claimed
`
`invention except that while Kane discloses that it is known to use a laser for providing
`
`energy to an ionized gas to sustain a plasma “More commonly, laser-based sources of
`
`high-peak power UV radiation are used for such applications” [col. 8; lines 6-8], there is
`
`

`
`Application/Control Number: 14/510,959
`
`Page 13
`
`Art Unit: 2881
`
`no explicit disclosure of at least one laser for providing energy to the ionized gas to
`
`sustain a plasma within the chamber to produce a plasma-generated light.
`
`Cross discloses that “free—standing continuous discharges have been produced
`
`by focusing the output of a sufficiently powerful cw-CO2 laser into inert gases, molecular
`
`gases and mixtures thereof at atmospheric pressures or above... Although cw-laser
`
`radiation can maintain the continuous optical discharge, the output power of such light
`
`sources is generally insufficient to initiate the discharge. Consequently, such plasmas
`
`can be initiated using conventional electrode sparks or by the spark produced by a
`
`focused laser pulse superimposed on the focal volume of the cw-laser beam used to
`
`maintain the plasma” [col. 1; lines 30-52]. Cross illustrates in figure 1 that cw-laser (10)
`
`is external to the chamber in which the plasma is sustained and Cross discloses at least
`
`one optical element for passing the electromagnetic energy generated by the at least
`
`one laser to the pressurized chamber. It would have been obvious to one possessing
`
`ordinary skill in the art at the time of the invention to have combined Kane and Cross in
`
`order to maintain the light emitted from a plasma for a desired amount of time after the
`
`plasma is initially produced by an electrode discharge. Kane and Cross disclose the
`
`claimed invention except that while Kane discloses a curved reflector (illustrated in
`
`figure 12), there is no explicit disclosure that such a reflector reflects at least a portion of
`
`the electromagnetic energy provided by the at least one external laser.
`
`Ershov discloses a laser source for creating a plasma “a laser produced plasma”
`
`[Abstract] which emits light “light generated in a plasma produced at the plasma
`
`initiation site” [0008]. The laser may be external to the plasma chamber “the laser input
`
`

`
`Application/Control Number: 14/510,959
`
`Page 14
`
`Art Unit: 2881
`
`window 202, which may be utilized for vacuum sealing the chamber 26 and laser
`
`delivery enclosure 300 are not in direct line of view of plasma initiation site” [0040] and
`
`may be provided to the plasma location by at least one optical element reflecting the
`
`electromagnetic energy generated by the at least one laser to the chamber “Mirror 170
`
`may, e.g., be a flat or curved mirror made, e.g., of molybdenum” [0035]; and a curved
`
`reflective surface receiving and reflecting at least a portion of the electromagnetic
`
`energy toward the plasma location to produce a plasma that generates plasma-
`
`generated light emitted by the plasma “The final focusing mirror 180 can, e.g., focuses
`
`CO2 radiation in a C02 drive laser input beam 172, redirected by the redirecting mirror
`
`170 into the focusing mirror 180 to form a focused beam 176 intersecting the target
`
`droplets 92 at the desired plasma initiation site 28” [0035] and reflecting the plasma-
`
`generated light toward an output of the light source. Figure 5 illustrates that light
`
`generated by the plasma at the irradiation site (28) which is directed back at the mirror
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`(180’) will be reflected in the direction of intermediate focus (40) and thus toward the
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`output " intermediate point 40 (also called the intermediate focus 40) where the EUV
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`light is output from the light source and input to, e.g., an integrated circuit lithography
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`tool (not shown)” [0023]. It would have been obvious to one possessing ordinary skill in
`
`the art at the time of the invention to have utilized the drive laser configuration of Ershov
`
`in the apparatuses of Kane or Cross in order to provide optimally focused laser
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`irradiation to the plasma location from an off-axis laser source so that the laser source
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`may be provided externally to the desired pressure within the plasma chamber and so
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`Application/Control Number: 14/510,959
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`Page 15
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`Art Unit: 2881
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`that the laser source is not located so as to interfere with the direction of the radiation
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`produced by the plasma.
`
`Regarding claim 21, Kane disclsoes the claimed invention except that while Kane
`
`discloses a curved reflector (illustrated in figure 12), there is no explicit disclosure that
`
`such a reflector reflects at least a portion of the electromagnetic energy provided by the
`
`at least one external laser.
`
`Ershov discloses that curved reflector (180) focuses the electromagnetic energy
`
`on a region in the chamber (28) where the plasma is located “The final focusing mirror
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`180 can, e.g., focuses CO2 radiation in a C02 drive laser input beam 172, redirected by
`
`the redirecting mirror 170 into the focusing mirror 180 to form a focused beam 176
`
`intersecting the target droplets 92 at the desired plasma initiation site 28” [0035].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have utilized the drive laser configuration of Ershov in the
`
`apparatuses of Kane or Cross in order to provide optimally focused laser irradiation to
`
`the plasma location from an off-axis laser source so that the laser source may be
`
`provided externally to the desired pressure within the plasma chamber and so that the
`
`laser source is not located so as to interfere with the direction of the radiation produced
`
`by the plasma.
`
`Regarding claim 22, Kane disclsoes the claimed invention except that while Kane
`
`discloses a curved reflector (illustrated in figure 12), there is no explicit disclosure that
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`Art Unit: 2881
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`such a reflector reflects at least a portion of the electromagnetic energy provided by the
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`at least one external laser.
`
`Ershov illustrates in figure 5 that curved reflector (180’) is located within the
`
`chamber since Ershov discloses that the window (202) separates the interior of the
`
`chamber from the exterior “the laser input window 202, which may be utilized for
`
`vacuum sealing the chamber 26” [0040].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have utilized the drive laser configuration of Ershov in the
`
`apparatuses of Kane or Cross in order to provide optimally focused laser irradiation to
`
`the plasma location from an off-axis laser source so that the laser source may be
`
`provided externally to the desired pressure within the plasma chamber and so that the
`
`laser source is not located so as to interfere with the direction of the radiation produced
`
`by the plasma.
`
`Regarding claim 24, Kane disclsoes the claimed invention except that while Kane
`
`discloses a curved reflector (illustrated in figure 12), there is no explicit disclosure that
`
`such a reflector reflects at least a portion of the electromagnetic energy provided by the
`
`at least one external laser.
`
`Ershov illustrates in figure 5 that curved reflector (180’) is located within the
`
`chamber since Ershov discloses that the window (202) separates the interior of the
`
`chamber from the exterior “the laser input window 202, which may be utilized for
`
`vacuum sealing the chamber 26” [0040].
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`Art Unit: 2881
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`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have utilized the drive laser configuration of Ershov in the
`
`apparatuses of Kane or Cross in order to provide optimally focused laser irradiation to
`
`the plasma location from an off-axis laser source so that the laser source may be
`
`provided externally to the desired pressure within the plasma chamber and so that the
`
`laser source is not located so as to interfere with the direction of the radiation produced
`
`by the plasma.
`
`Regarding claim 29, Kane discloses “The lamp comprises... two electrodes
`
`disposed with respect to the chamber for discharging electrical energy therebetween
`
`whereby, in use, a substantially homogeneous discharge occurs between the two
`
`electrodes which causes emission of incoherent radiation pulses of high peak power
`
`from the lamp” [Abstract].
`
`Regarding claim 30, Kane discloses the claimed invention except that while Kane
`
`discloses that it is known to use a laser for providing energy to an ionized gas to sustain
`
`a plasma “More commonly, laser—based sources of high-peak power UV radiation are
`
`used for such applications” [col. 8; lines 6-8], there is no explicit disclosure of at least
`
`one laser for providing energy to the ionized gas to sustain a plasma within the chamber
`
`to produce a plasma—generated light.
`
`Cross discloses that “free—standing continuous discharges have been produced
`
`by focusing the output of a sufficiently powerful cw-CO2 laser into inert gases, molecular
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`gases and mixtures thereof at atmospheric pressures or above... Although cw-laser
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`radiation can maintain the continuous optical discharge, the output power of such light
`
`sources is generally insufficient to initiate the discharge. Consequently, such plasmas
`
`can be initiated using conventional electrode sparks or by the spark produced by a
`
`focused laser pulse superimposed on the focal volume of the cw-laser beam used to
`
`maintain the plasma” [col. 1; lines 30-52].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Kane and Cross in order to maintain the light emitted
`
`from a plasma for a desired amount of time after the plasma is initially produced by an
`
`electrode discharge.
`
`8.
`
`Claims 11 and 12 are rejected under pre-AIA 35 U.S.C. 103(a) as being
`
`unpatentable over Kane et al. U.S. Patent No. 6,541,924 in view of Cross et al. U.S.
`
`Patent No. 4,780,608 in further view of Eastlund et al. U.S. PGPUB No. 2003/0052609.
`
`Regarding claim 11,