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.
`
`13/964,938
`
`08/12/2013
`
`Donald K. Smith
`
`EGQ—005CP3C1
`
`1022
`
`42532
`7590
`PROSKAUER ROSE LLP
`ONE INTERNATIONAL PLACE
`BOSTON, MA 02110
`
`07/17/2014
`
`MCCORMACK, JASON L
`
`2881
`
`07/ 1 7/2014
`
`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)
`
`ASML 1108
`
`

`
`Application No.
`13/964,938
`
`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 § MONTH(S) OR THIRTY (30) DAYS,
`WHICHEVER IS LONGER, FROM THE MAILING DATE OF THIS COMMUNICATION.
`Extensions of time may be available under the provisions of 37 CFR 1.136(a).
`In no event, however, may a reply be timely filed
`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).
`
`—
`—
`
`Status
`
`1)IXI Responsive to communication(s) filed on 17June 2014.
`I:I A declaration(s)/affidavit(s) under 37 CFR 1.130(b) was/were filed on
`
`2b)I:I This action is non—final.
`2a)IZI 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)
`is/are withdrawn from consideration.
`6 I:I Claim s) j is/are allowed.
`s) 1—_.3‘0 is/are rejected.
`
`) _ is/are objected to.
`
`)_ are subject to restriction and/or election requirement.
`* 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
`
`
`
`://www.uspto. ov/ atents/init events/'
`if/'index.‘s orsend an inquiry to PPI--lfeedback@usjgjtoxzov.
`
`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)
`_
`_
`2) X Information Disclosure Statement(s) (PTO/SB/08)
`Paper No(s)/Mail Date 3/11/2014 5/17/2014.
`U.S. Patent and Trademark Office
`PTOL—326 (Rev. 05-13)
`
`Office Action Summary
`
`Part of Paper No./Mail Date 20140623
`
`3) D jntervjew summary (pTo-413)
`Paper No(s)/Mail Date. j
`4) I:I Other‘ :-
`
`
`
`

`
`Application/Control Number: 13/964,938
`
`Page 2
`
`Art Unit: 2881
`
`DETAILED ACTION
`
`Response to Arguments
`
`1.
`
`Applicant's arguments filed 6/17/2014 have been fully considered but they are
`
`not persuasive.
`
`Regarding applicant’s argument (beginning on page 9) that Wester fails to
`
`disclose a pressurized plasma chamber; Wester discloses “a vacuum pump 118
`
`removes exhaust plasma gas from the chamber 120” [0005]. Since it is impossible for
`
`the vacuum pump 118 of Wester to form a perfect vacuum, the chamber inherently has
`
`some gas pressure and is therefore pressurized as required by claim 1.
`
`It is believed
`
`from applicant's specification and the response that applicant intends for the chamber to
`
`operate above atmospheric pressure (particularly since paragraph [0069] describes that
`
`the chamber operates "at a pressure of greater than 10 atmospheres to produce a high
`
`brightness light”). However, MPEP 2111.01 describes that “the claims must be
`
`interpreted as broadly as their terms reasonably allow. In re American Academy of
`
`Science Tech Center, 367 F.3d 1359, 1369, 70 USPQ2d 1827, 1834 (Fed. Cir. 2004)”.
`
`Such an interpretation of the term “pressurized" is not unreasonable since, for example,
`
`Kisa U.S. Patent No. 4,738,748 describes in its claim 11 "an airtight vacuum
`
`pressurized reaction chamber having a vacuum created therein”. Clearly, one of
`
`ordinary skill in the art at the time of the invention would recognize that a chamber that
`
`is pressurized to a vacuum condition is still considered “pressurized”. For this reason,
`
`the current rejection in view of Wester remains proper.
`
`

`
`Application/Control Number: 13/964,938
`
`Page 3
`
`Art Unit: 2881
`
`If, however, the claims were to be amended and/or interpreted that the term
`
`"pressurized" referred to "above atmospheric pressure", Bykanov et al. U.S. PGPUB
`
`No. 2006/0097203 describes that ''In a typical LPP setup, it may be desirable to
`
`maintain a relatively strong vacuum in the chamber 806, and thus, the amount of
`
`etchant introduced into the chamber 806 is limited. As a consequence, the allowable
`
`etchant flow rate and pressure are generally too small to effectively heat the window
`
`800 to a temperature sufficient to achieve a reasonable reaction rate between the
`
`etchant and debris deposits. For example, HBr gas at 600 degrees C. and at a pressure
`
`of 1 to 2 torr in the gas cone can only transport about 1 Watt of heating power at typical
`
`flow rates. On the other hand, when applying a heated gas to the outside surface 808,
`
`an elevated (greater than 1 atm) pressure can be used allowing the mass flow to be
`
`significantly higher and a power in the range of about 10.sup.1-10.sup.2 W is feasible”
`
`[0063]. It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Bykanov, since Bykanov describes that a
`
`typical low-pressure system (such as that of Wester) may be modified by the application
`
`of a heated gas outside of a laser irradiation window to operate at pressures greater
`
`than 1 atm (above atmospheric pressure), in order to prevent the buildup of undesirable
`
`debris on delicate optical systems, and to "significantly” increase the power of the
`
`ultraviolet beam output from the plasma. However, Examiner maintains that such an
`
`interpretation need to apply to the present claim language.
`
`Applicant cited Tejnil U.S. PGPUB No. 2005/0243390 (on page 10) as evidence
`
`that pressurizing the chamber of Wester would prevent the light source of Wester from
`
`

`
`Application/Control Number: 13/964,938
`
`Page 4
`
`Art Unit: 2881
`
`producing EUV light. As stated, above, the chamber of Wester may already be
`
`considered “pressurized”. Additionally, as stated, above, it would have been obvious to
`
`operate the chamber of Wester above atmospheric pressure in order to prevent debris
`
`buildup in the plasma chamber. The portion of Tejnil cited in applicant's remarks
`
`pertains to "EUV imaging" and is silent regarding chamber pressures of a plasma
`
`chamber during the formation of a plasma. Further, Tejnil states that EUV imaging
`
`"may" be carried out in a near vacuum. As stated, above, it is Examiner's position that a
`
`"near vacuum" is pressurized above a vacuum state. Additionally, this portion of Tejnil
`
`merely states that EUV imaging may be in a vacuum, thereby leaving the possibility that
`
`it may not be performed in a vacuum. Tejnil does not include a specific teaching that
`
`EUV radiation cannot or should not be formed except in a vacuum.
`
`Applicant cites (on page 10) the entry "extreme ultraviolet radiation" in McGraw-
`
`Hill Dictionary of Scientific and Technical Terms; this merely teaches that extreme
`
`ultraviolet radiation may sometimes be referred to as "vacuum ultraviolet radiation" and
`
`is silent regarding the conditions of a plasma chamber in which such radiation may be
`
`formed — particularly in the field of a laser produced plasma.
`
`Applicant contends (on page 10) that claim 1 relates to high brightness light in a
`
`wavelength between 290 and 400 nm. It is noted that the brightness and wavelength
`
`are not recited in the rejected claim(s). Although the claims are interpreted in light of
`
`the specification, limitations from the specification are not read into the claims. See In
`
`re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Applicant’s claims do
`
`not distinguish the difference between EUV radiation and high brightness radiation, but
`
`

`
`Application/Control Number: 13/964,938
`
`Page 5
`
`Art Unit: 2881
`
`instead merely claim that “light” is generated from the plasma formed when a laser
`
`irradiates a gas.
`
`Regarding applicant’s argument (on page 13) that it would not have been
`
`obvious to combine Wester and Mizoguchi; Wester requires a “high energy laser beam”
`
`[0002] but does not specify the type of laser. The laser source system of Mizoguchi
`
`comprises a continuous wave laser (as required by claim 8) as part of a larger system
`
`(claim 8 does not specify that the laser system consists only of the continous wave
`
`laser), and it would have been obvious to combine Wester and Mizoguchi, since Wester
`
`requires a laser, and Mizoguchi discloses a suitable laser, in order to substitute specific
`
`types of laser configurations for the requisite laser of Wester.
`
`Claim Rejections - 35 USC § 102
`
`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.
`Claims 1, 7, 9, 10, 12, 13, 14, 15, 20, 26, and 28 are rejected under pre-AIA 35
`
`2.
`
`U.S.C. 102(b) as being anticipated by Wester U.S. PGPUB No. 2004/0016894.
`
`Regarding claim 1, Wester discloses a method for illuminating features of a
`
`semiconductor wafer “Photolithography systems are used to produce circuit patterns on
`
`semiconductor wafers” [0002], comprising: ionizing a gas “ionize a gas to form a
`
`plasma” [0002] within a plasma chamber “a chamber 120 for generating EUV light”
`
`

`
`Application/Control Number: 13/964,938
`
`Page 6
`
`Art Unit: 2881
`
`[0005]; providing laser energy to the ionized gas to sustain a plasma within the plasma
`
`chamber to produce plasma—generated light “the plasma may be generated by focusing
`
`a high energy laser beam onto a stream of inert gas, such as Xenon” [0002]; and
`
`illuminating the wafer with the plasma—generated light “EUV lithographic system 100
`
`includes a chamber 120 for generating EUV light and a chamber 122 for using the EUV
`
`light to produce lithography patterns on a wafer 114” [0005].
`
`Regarding claim 7, Wester discloses laser produced plasma as an alternative to
`
`discharge produced plasma (with an electrode) “The plasma may be generated by
`
`focusing a high energy laser beam onto a stream of inert gas, such as Xenon. The
`
`plasma may also be produced by using electron emission in which electrodes emit
`
`electrons to ionize a gas to form a plasma.” [0002].
`
`Regarding claim 9, Wester discloses generating extreme ultraviolet light
`
`[Abstract].
`
`Regarding claim 10, Wester discloses a method for measuring features of a
`
`semiconductor wafer “Photolithography systems are used to produce circuit patterns on
`
`semiconductor wafers” [0002], comprising: ionizing a gas “ionize a gas to form a
`
`plasma” [0002] within a plasma chamber “a chamber 120 for generating EUV light”
`
`[0005]; providing laser energy to the ionized gas to sustain a plasma within the plasma
`
`chamber to produce plasma—generated light “the plasma may be generated by focusing
`
`

`
`Application/Control Number: 13/964,938
`
`Page 7
`
`Art Unit: 2881
`
`a high energy laser beam onto a stream of inert gas, such as Xenon” [0002]; and
`
`illuminating the wafer with the plasma—generated light “EUV lithographic system 100
`
`includes a chamber 120 for generating EUV light and a chamber 122 for using the EUV
`
`light to produce lithography patterns on a wafer 114” [0005] and providing the plasma-
`
`generated light emitted by the ionized gas to a device selected from the group
`
`consisting of a wafer inspection tool, a microscope, a metrology tool, and a lithography
`
`tool “EUV lithographic system 100 includes a chamber 120 for generating EUV light and
`
`a chamber 122 for using the EUV light to produce lithography patterns on a wafer 114”
`
`[ooo51
`
`Regarding claim 12, Wester discloses laser produced plasma as an alternative to
`
`discharge produced plasma (with an electrode) “The plasma may be generated by
`
`focusing a high energy laser beam onto a stream of inert gas, such as Xenon. The
`
`plasma may also be produced by using electron emission in which electrodes emit
`
`electrons to ionize a gas to form a plasma.” [0002].
`
`Regarding claim 13, Wester discloses a system comprising: a plasma chamber
`
`“a chamber 120 for generating EUV light” [0005] having an ionized gas therein “ionize a
`
`gas to form a plasma” [0002]; a laser for providing substantially continuous energy to
`
`the ionized gas within the chamber to sustain to sustain a plasma and produce plasma-
`
`generated light “the plasma may be generated by focusing a high energy laser beam
`
`onto a stream of inert gas, such as Xenon” [0002]; and a tool optically coupled to the
`
`

`
`Application/Control Number: 13/964,938
`
`Page 8
`
`Art Unit: 2881
`
`chamber that uses the plasma—generated light to illuminate a wafer “EUV lithographic
`
`system 100 includes a chamber 120 for generating EUV light and a chamber 122 for
`
`using the EUV light to produce lithography patterns on a wafer 114” [0005].
`
`Regarding claim 14, Wester discloses that “the plasma may be generated by
`
`focusing a high energy laser beam onto a stream of inert gas, such as Xenon” [0002].
`
`Regarding claim 15, Wester discloses laser produced plasma as an alternative to
`
`discharge produced plasma (with an electrode) “The plasma may be generated by
`
`focusing a high energy laser beam onto a stream of inert gas, such as Xenon. The
`
`plasma may also be produced by using electron emission in which electrodes emit
`
`electrons to ionize a gas to form a plasma.” [0002].
`
`Regarding claim 20, Wester discloses that “EUV lithographic system 100
`
`includes a chamber 120 for generating EUV light and a chamber 122 for using the EUV
`
`light to produce lithography patterns on a wafer 114” [0005].
`
`Regarding claim 26, Wester discloses a method for illuminating features of a
`
`semiconductor wafer “Photolithography systems are used to produce circuit patterns on
`
`semiconductor wafers” [0002], comprising: ionizing a gas “ionize a gas to form a
`
`plasma” [0002] within a plasma chamber “a chamber 120 for generating EUV light”
`
`[0005]; providing laser energy to the ionized gas to sustain a plasma within the plasma
`
`

`
`Application/Control Number: 13/964,938
`
`Page 9
`
`Art Unit: 2881
`
`chamber to produce plasma—generated light “the plasma may be generated by focusing
`
`a high energy laser beam onto a stream of inert gas, such as Xenon” [0002]; and
`
`illuminating the wafer with the plasma-generated light “EUV lithographic system 100
`
`includes a chamber 120 for generating EUV light and a chamber 122 for using the EUV
`
`light to produce lithography patterns on a wafer 114” [0005].
`
`Regarding claim 28, Wester discloses that “The plasma may be generated by
`
`focusing a high energy laser beam onto a stream of inert gas, such as Xenon” [0002].
`
`Applicant’s specification, at paragraph [0014] defines that the ignition source “can be a
`
`continuous wave (CW) or pulsed laser impinging on a solid or liquid target in the
`
`chamber”. Additionally, paragraph [0018] describes that “the lights source includes a
`
`chamber and an ignition source”. It is not clear from the claims that the laser source of
`
`claim 26 is separate from the ignition source. Therefore, it is understood that the laser
`
`source, operates during the ignition source since the two as the same.
`
`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.
`
`

`
`Application/Control Number: 13/964,938
`
`Page 10
`
`Art Unit: 2881
`
`3.
`
`Claims 2, 4, and 19 are rejected under pre-AIA 35 U.S.C. 103(a) as being
`
`unpatentable over Wester U.S. PGPUB No. 2004/0016894 in view of Tejnil U.S.
`
`PGPUB No. 2005/0243390.
`
`Regarding claim 2, Wester discloses the claimed invention except that there is no
`
`explicit recitation that the extreme ultraviolet light may be utilized for measuring features
`
`of a wafer.
`
`Tenjil discloses that "extreme ultraviolet (1) radiation... may be used in the
`
`manufacture and inspection of microelectronic semiconductor devices with feature sizes
`
`less than 100 nm” [0001].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Tenjil in order to utilize a laser produced
`
`plasma generating extreme ultraviolet light as a light source for an inspection tool.
`
`Regarding claim 4, Wester discloses the claimed invention except that there is no
`
`explicit recitation that the extreme ultraviolet light may be utilized for measuring features
`
`of a wafer.
`
`Tenjil discloses that "extreme ultraviolet (EUV) radiation... may be used in the
`
`manufacture and inspection of microelectronic semiconductor devices with feature sizes
`
`less than 100 nm” [0001]. The light is delivered to the substrate by optical element
`
`(120).
`
`

`
`Application/Control Number: 13/964,938
`
`Page 11
`
`Art Unit: 2881
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Tenjil in order to utilize a laser produced
`
`plasma generating extreme ultraviolet light as a light source for an inspection tool.
`
`Regarding claim 19, Wester discloses the claimed invention except that there is
`
`no explicit recitation that the extreme ultraviolet light may be utilized for measuring
`
`features of a wafer.
`
`Tenjil discloses that "extreme ultraviolet (EUV) radiation... may be used in the
`
`manufacture and inspection of microelectronic semiconductor devices with feature sizes
`
`less than 100 nm” [0001]. The light is delivered to the substrate by optical element
`
`(120), which changes the direction and focal point of the light, as illustrated in figure 1A.
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Tenjil in order to utilize a laser produced
`
`plasma generating extreme ultraviolet light as a light source for an inspection tool.
`
`4.
`
`Claims 3, 5, 11, 17, and 18 are rejected under pre-AIA 35 U.S.C. 103(a) as being
`
`unpatentable over Wester U.S. PGPUB No. 2004/0016894 in view of Hiramoto et al.
`
`U.S. PGPUB No. 2004/0183038.
`
`Regarding claim 3, Wester discloses the claimed invention except that while
`
`Wester discloses that the laser is focused [OOO2], there is no explicit disclosure of an
`
`optical element.
`
`

`
`Application/Control Number: 13/964,938
`
`Page 12
`
`Art Unit: 2881
`
`Hiramoto discloses an extreme ultraviolet light generating apparatus wherein “the
`
`Nd :YAG laser light is focused by means of a lens 8, irradiation and heating/excitation
`
`are carried out and a plasma is produced, by which extreme UV light with a main
`
`wavelength of 13.5 nm is emitted” [0045]. The laser’s focus is an optical property which
`
`is modified by the lens.
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Hiramoto in order to provide optimal
`
`focusing to deliver the maximum amount of energy from the laser to the target ignition
`
`point for generating a laser produced plasma.
`
`Regarding claim 5, Wester discloses the claimed invention except that while
`
`there is no explicit disclosure of the type of laser source.
`
`Hiramoto discloses an extreme ultraviolet light generating apparatus wherein “the
`
`Nd :YAG laser light is focused by means of a lens 8, irradiation and heating/excitation
`
`are carried out and a plasma is produced, by which extreme UV light with a main
`
`wavelength of 13.5 nm is emitted” [0045].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Hiramoto in order to utilize a pre-existing
`
`laser source to deliver the plasma generating energy for generating the extreme
`
`ultraviolet light.
`
`

`
`Application/Control Number: 13/964,938
`
`Page 13
`
`Art Unit: 2881
`
`Regarding claim 11, Wester discloses the claimed invention except that while
`
`Wester discloses that the laser is focused [OOO2], there is no explicit disclosure of an
`
`optical element.
`
`Hiramoto discloses an extreme ultraviolet light generating apparatus wherein “the
`
`Nd :YAG laser light is focused by means of a lens 8, irradiation and heating/excitation
`
`are carried out and a plasma is produced, by which extreme UV light with a main
`
`wavelength of 13.5 nm is emitted” [0045]. The laser’s focus is an optical property which
`
`is modified by the lens.
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Hiramoto in order to provide optimal
`
`focusing to deliver the maximum amount of energy from the laser to the target ignition
`
`point for generating a laser produced plasma.
`
`Regarding claim 17, Wester discloses the claimed invention except that while
`
`there is no explicit disclosure of the type of laser source.
`
`Hiramoto discloses an extreme ultraviolet light generating apparatus wherein “the
`
`Nd :YAG laser light is focused by means of a lens 8, irradiation and heating/excitation
`
`are carried out and a plasma is produced, by which extreme UV light with a main
`
`wavelength of 13.5 nm is emitted” [0045].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Hiramoto in order to utilize a pre-existing
`
`

`
`Application/Control Number: 13/964,938
`
`Page 14
`
`Art Unit: 2881
`
`laser source to deliver the plasma generating energy for generating the extreme
`
`ultraviolet light.
`
`Regarding claim 18, Wester discloses the claimed invention except that while
`
`Wester discloses that the laser is focused [OOO2], there is no explicit disclosure of an
`
`optical element.
`
`Hiramoto discloses an extreme ultraviolet light generating apparatus wherein “the
`
`Nd :YAG laser light is focused by means of a lens 8, irradiation and heating/excitation
`
`are carried out and a plasma is produced, by which extreme UV light with a main
`
`wavelength of 13.5 nm is emitted” [0045]. The lens converges the beam to a focal point.
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Hiramoto in order to provide optimal
`
`focusing to deliver the maximum amount of energy from the laser to the target ignition
`
`point for generating a laser produced plasma.
`
`5.
`
`Claim 6 is rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over
`
`Wester U.S. PGPUB No. 2004/0016894 in view of Partlo et al. U.S. PGPUB No.
`
`2005/0205811.
`
`Regarding claim 6, Wester discloses the claimed invention but does not explicitly
`
`disclose the specific wavelength of the laser.
`
`

`
`Application/Control Number: 13/964,938
`
`Page 15
`
`Art Unit: 2881
`
`Partlo discloses an extreme ultraviolet radiation generating apparatus wherein
`
`"The plasma irradiation pulse may comprise a laser pulse having a wavelength that is
`
`sufficiently longer than a wavelength of the initial target irradiation pulse to have an
`
`associated lower critical density resulting in absorption occurring within the plasma in a
`
`region of the plasma defined by the wavelength of the plasma irradiation pulse
`
`sufficiently separated from an initial target irradiation site to achieve compression of the
`
`emission material, and the may compress the emission region” [0015].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Partlo in order to deliver laser radiation of
`
`a wavelength that ensures that a target material generates an optimal level of extreme
`
`ultraviolet light. Partlo discloses the claimed invention except for the specifically claimed
`
`wavelengths of light.
`
`It would have been obvious to one having ordinary skill in the art at
`
`the time the invention was made to use the claimed wavelength of light since it has
`
`been held that where the general conditions of a claim are disclosed in the prior art,
`
`discovering the optimum or workable ranges involves only routine skill in the art. One
`
`would have been motivated to use the claimed wavelength of light for the purpose of
`
`matching the energy of a drive laser to the energy requirement needed to create plasma
`
`using a particular target source material. In re AI/er, 220 F.2d 454, 456, 105 USPQ 233,
`
`235.
`
`

`
`Application/Control Number: 13/964,938
`
`Page 16
`
`Art Unit: 2881
`
`6.
`
`Claims 8 and 16 are rejected under pre-AIA 35 U.S.C. 103(a) as being
`
`unpatentable over Wester U.S. PGPUB No. 2004/0016894 in view of Mizoguchi et al.
`
`U.S. PGPUB No. 2004/0238762.
`
`Regarding claim 8, Wester discloses the claimed invention but does not explicitly
`
`disclose that the laser source comprises a continuous wave laser.
`
`Mizoguchi discloses that the drive laser in a laser produced plasma source for
`
`generating extreme ultraviolet light [Abstract] may comprise a continuous wave laser
`
`[OO87—O088].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Mizoguchi in order to select a particular
`
`type of existing laser source for delivering a particularly desired amount of energy to a
`
`target region so as to produce extreme ultraviolet light form a plasma generated by the
`
`irradiation of the laser source to the target material.
`
`Regarding claim 16, Wester discloses the claimed invention but does not
`
`explicitly disclose that the laser source comprises a continuous wave laser.
`
`Mizoguchi discloses that the drive laser in a laser produced plasma source for
`
`generating extreme ultraviolet light [Abstract] may comprise a continuous wave laser
`
`[OO87—O088].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Mizoguchi in order to select a particular
`
`

`
`Application/Control Number: 13/964,938
`
`Page 17
`
`Art Unit: 2881
`
`type of existing laser source for delivering a particularly desired amount of energy to a
`
`target region so as to produce extreme ultraviolet light form a plasma generated by the
`
`irradiation of the laser source to the target material.
`
`7.
`
`Claims 21, 22, 23, 25, and 30 are rejected under pre-AIA 35 U.S.C. 103(a) as
`
`being unpatentable over Wester U.S. PGPUB No. 2004/0016894 in view of Jaegle et al.
`
`U.S. Patent No. 3,826,996.
`
`Regarding claim 21, Wester discloses a plasma-based light source “a plasma
`
`that generates EUV light” [Abstract] comprising: a pressurized “A vacuum pump 118
`
`removes exhaust plasma gas from chamber 120” [0005] plasma chamber “chamber 120
`
`for generating EUV light” [0005] configured to contain an ionized gas “ionize a stream of
`
`gas (e.g., Xenon gas) to produce a plasma 104” [0005]; a laser system for generating a
`
`beam of laser energy “The plasma may be generated by focusing a high energy laser
`
`beam onto a stream of inert gas, such as Xenon” [0002]; and a tool optically coupled to
`
`the chamber for receiving light generated by the plasma “a chamber 120 for generating
`
`EUV light and a chamber 122 for using the EUV light to produce lithography patterns on
`
`a wafer 114” [0005]. Wester discloses the claimed invention except that while Wester
`
`illustrates in figure 2 that plasma (104) has an elongated form, and discusses that the
`
`"shape and position" of the plasma may be selected [0014], there is no explicit
`
`disclosure of an optical system coupled to the laser for modifying an optical property of
`
`the beam of laser energy, the optical system configured to direct the beam to the
`
`

`
`Application/Control Number: 13/964,938
`
`Page 18
`
`Art Unit: 2881
`
`ionized gas within the chamber in order to sustain in the chamber a plasma having an
`
`elongated form with a plasma length that is substantially greater than that of a plasma
`
`diameter.
`
`Jaegle discloses that an optical system may be used with the drive laser (24) of a
`
`laser produced plasma system, wherein "The optical system 28 can be either a
`
`cylindrical or spherical system: in the former case, the plasma 30 which is formed on the
`
`target 22 has an elongated shape and in the latter case has a shape which is initially
`
`spherical at the moment of formation (prior to expansion)” [col. 9; lines 63-68].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Jaegle in order to provide a plasma
`
`having a shape which is optimal for formation of light of a particular wavelength, or
`
`which is of a shape optimal for the shape of the cavity in which the plasma is formed.
`
`Regarding claim 22, Wester discloses the claimed invention except that while
`
`Wester illustrates in figure 2 that plasma (104) has an elongated form, and discusses
`
`that the "shape and position" of the plasma may be selected [OO14], there is no explicit
`
`disclosure of an optical system coupled to the laser for modifying an optical property of
`
`the beam of laser energy, the optical system configured to direct the beam to the
`
`ionized gas within the chamber in order to sustain in the chamber a plasma having an
`
`elongated form with a plasma length that is substantially greater than that of a plasma
`
`diameter.
`
`

`
`Application/Control Number: 13/964,938
`
`Page 19
`
`Art Unit: 2881
`
`Jaegle discloses that an optical system may be used with the drive laser (24) of a
`
`laser produced plasma system, wherein "The optical system 28 can be either a
`
`cylindrical or spherical system: in the former case, the plasma 30 which is formed on the
`
`target 22 has an elongated shape and in the latter case has a shape which is initially
`
`spherical at the moment of formation (prior to expansion)” [col. 9; lines 63-68].
`
`It would have been obvious to one possessing ordinary skill in the art at the time
`
`of the invention to have combined Wester and Jaegle in order to provide a plasma
`
`having a shape which is optimal for formation of light of a particular wavelength, or
`
`which is of a shape opt