DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Status
Acknowledgment is made of the amendment filed on 11/18/2025, which amended claims 1 and 14. Claims 1-20 are currently pending.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 12/18/2025 has been entered.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-17 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Regarding claim 1, the limitations “a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; a gas supplier configured to supply a hydrogen gas along a surface of the condensing mirror and to the cleaning cell” in lines 7-10 were not described in the specification to reasonably convey to one of ordinary skill in the art that the inventor had possession of an exposure apparatus with the recited cleaning cell and the gas supplier configured to supply a hydrogen gas along a surface of the condensing mirror and to the cleaning cell at the time of filing. Although Fig. 3 and paras. [0046]-[0056] of the publication of the instant application, US PGPub 2024/0094646, describes a cleaning cell 305 and a hydrogen gas supplier 306, the disclosure does not describe the cleaning cell is part of an exposure apparatus comprising “a droplet supplier configured to supply a target droplet inside a vacuum chamber, an irradiator configured to irradiate a pulsed laser onto the target droplet” in combination with the other structural limitations of the recited exposure apparatus and does not describe that the gas supplier supplies hydrogen gas along a surface of the condensing mirror and to the cleaning cell because Fig. 3 and paras. [0046]-[0056] fails to describe a condensing mirror “being configured to condense a light emitted from the target droplet by irradiation of the pulsed laser onto the target droplet.” Fig. 1 and paras. [0021]-[0022] and [0026] describe a hydrogen gas supplier 105 that supplies gas into the vacuum chamber 101 including condensing mirror 104, but the embodiment of Fig. 1 does not support that the inventor possessed “a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; a gas supplier configured to supply a hydrogen gas along a surface of the condensing mirror and to the cleaning cell.” Furthermore, the Applicant has not specifically pointed out where the amended claim is supported, nor does there appear to be a written description of the claim limitations “a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; a gas supplier configured to supply a hydrogen gas along a surface of the condensing mirror and to the cleaning cell” in the application as filed. The specification does not reasonably convey that one of ordinary skill in the art had possession of the claimed subject matter “an exposure apparatus” comprising “a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; a gas supplier configured to supply a hydrogen gas along a surface of the condensing mirror and to the cleaning cell” at the time the application was filed. Claim 1 and all claims depending therefrom are rejected for failing to comply with the written description requirement. Appropriate correction is required.
Regarding claim 14, the limitations “a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; a gas supplier configured to supply a hydrogen gas along a surface of the condensing mirror and to the cleaning cell” in lines 7-10 were not described in the specification to reasonably convey to one of ordinary skill in the art that the inventor had possession of an exposure apparatus with the recited cleaning cell and the gas supplier configured to supply a hydrogen gas along a surface of the condensing mirror and to the cleaning cell at the time of filing. Although Fig. 3 and paras. [0046]-[0056] of US PGPub 2024/0094646, describes a cleaning cell 305 and a hydrogen gas supplier 306, the disclosure does not describe the cleaning cell is part of an exposure apparatus comprising “a droplet supplier configured to supply a target droplet inside a vacuum chamber, an irradiator configured to irradiate a pulsed laser onto the target droplet” in combination with the other structural limitations of the recited exposure apparatus and does not describe that the gas supplier supplies hydrogen gas along a surface of the condensing mirror and to the cleaning cell because Fig. 3 and paras. [0046]-[0056] fail to describe a condensing mirror “being configured to condense a light emitted from the target droplet by irradiation of the pulsed laser onto the target droplet.” Fig. 1 and paras. [0021]-[0022] and [0026] describe a hydrogen gas supplier 105 that supplies gas into the vacuum chamber 101 including condensing mirror 104, but the embodiment of Fig. 1 does not support that the inventor possessed “a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; a gas supplier configured to supply a hydrogen gas along a surface of the condensing mirror and to the cleaning cell.” Furthermore, the Applicant has not specifically pointed out where the amended claim is supported, nor does there appear to be a written description of the claim limitations “a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; a gas supplier configured to supply a hydrogen gas along a surface of the condensing mirror and to the cleaning cell” in the application as filed. The specification does not reasonably convey that one of ordinary skill in the art had possession of the claimed subject matter “an exposure apparatus” comprising “a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; a gas supplier configured to supply a hydrogen gas along a surface of the condensing mirror and to the cleaning cell” at the time the application was filed. Claim 14 and all claims depending therefrom are rejected as failing to comply with the written description requirement. Appropriate correction is required.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-9 and 12-17 are rejected under 35 U.S.C. 103 as being unpatentable over Bykanov et al. (US PGPub 2014/0110609, Bykanov hereinafter) in view of Yanagida et al. (US PGPub 2016/0073487, Yanagida hereinafter) in view of Wilhelmus Van Herpen et al. (US PGPub 2008/0001101, Herpen hereinafter).
Regarding claim 1, Bykanov discloses an exposure apparatus (Figs. 1-5, para. [0046]) comprising:
a droplet supplier configured to supply a target droplet inside a vacuum chamber (Figs. 1-5, paras. [0083], [0102], [0108], [0110], [0113]-[0114], source material delivery system 90 provides droplets inside a vacuum chamber 26);
an irradiator configured to irradiate a pulsed laser onto the target droplet (Figs. 1-5, paras. [0071]-[0073], [0079], [0085], a pulsed laser device 21 irradiates the pulsed laser onto droplets at irradiation region 48);
a condensing mirror in the vacuum chamber, the condensing mirror being configured to condense a light emitted from the target droplet by irradiation of the pulsed laser onto the target droplet (Figs. 1-5, paras. [0048]-[0049], [0065], [0071]-[0073], [0086], [0088], [0094], optic 24 is arranged in chamber 26 and condenses EUV radiation emitted by irradiating source material with laser pulses);
a gas supplier configured to supply a hydrogen gas along a surface of the condensing mirror (Figs. 1-5, paras. [0020], [0053]-[0055], [0057]-[0059], [0061], [0087], [0093], [0102], [0109], [0113], [0120]-[0121], [0129], gasses 28, 39, 39a, 39b, 39c, manifold 206 supply hydrogen gas along the surface of optic 24);
a controller (Fig. 1b, para. [0085], EUV controller 60) configured to change a supply condition of the target droplet and an irradiation condition of the pulsed laser to conditions that are different from conditions during an exposure operation to increase an amount of production of hydrogen radicals in the vacuum chamber (Figs. 1B-5, paras. [0051], [0053]-[0059], [0061], [0070], [0085], [0088]-[0096], [0099]-[0100], [0103]-[0106], [0112], [0116], [0120]-[0121], [0124]-[0129], EUV controller 60 controls the drive laser control system 65 to control the light pulses of pulsed laser device 21, and EUV controller 60 controls the droplet position, direction, timing, and droplet modulation of droplets from source material delivery system 90. The EUV controller controls the laser and source material supply during a cleaning process in a cleaning period different from the exposure bursts such that the cleaning species concentration of hydrogen radicals increases); and
an exhaust pump configured to exhaust a gas from an inside of the vacuum chamber (Figs. 1-5, paras. [0057], [0066], [0087], [0102], [0109], [0113], [0120]-[0121], [0128], pump 41 exhausts gas from the chamber 26), wherein the irradiator comprises a prepulse laser unit configured to irradiate a prepulse laser onto the target droplet in advance of the pulsed laser during the exposure operation to heat the target droplet and reduce a density of the target droplet (the limitation “to heat the target droplet and reduce a density of the target droplet” is functional language that recites the manner in which the claimed apparatus is operated and does not differentiate the claimed apparatus from the system taught by Bykanov. See MPEP 2114. Figs. 1B-5, paras. [0076], [0083], [0091], [0094], [0106], [0110]-[0112], [0116], pre-pulses are supplied in advance of the main pulses to the target droplet). Bykanov does not appear to explicitly describe the prepulse laser being an Nd:YAG laser and a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; and the gas supplier configured to supply the hydrogen gas along the surface of the condensing mirror and to the cleaning cell.
Yanagida discloses wherein the irradiator comprises a prepulse laser unit configured to irradiate a prepulse laser onto the target droplet in advance of the pulsed laser during the exposure operation to heat the target droplet and reduce a density of the target droplet, the prepulse laser being an Nd:YAG laser (Figs. 1-2, 4-7, 9, 28, 30, 31, 36, 37, paras. [0094]-[0096], [0106], [0110], [0123], [0254], [0257], [0295]-[0296], [0300], [0306]-[0307], [0383], pre-pulse laser beam irradiates the droplet target to expand the target to produce pre-plasma, and the pre-pulse laser is a Nd:YAG laser).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included wherein the irradiator comprises a prepulse laser unit configured to irradiate a prepulse laser onto the target droplet in advance of the pulsed laser during the exposure operation to heat the target droplet and reduce a density of the target droplet, the prepulse laser being an Nd:YAG laser as taught by Yanagida in the irradiator in the exposure apparatus as taught by Bykanov since including wherein the irradiator comprises a prepulse laser unit configured to irradiate a prepulse laser onto the target droplet in advance of the pulsed laser during the exposure operation to heat the target droplet and reduce a density of the target droplet, the prepulse laser being an Nd:YAG laser is commonly used to improve conversion efficiency of converting laser beam energy to EUV light energy (Yanagida, paras. [0095]-[0096], [0254], [0257]).
Bykanov as modified by Yanagida does not appear to explicitly describe a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; and the gas supplier configured to supply the hydrogen gas along the surface of the condensing mirror and to the cleaning cell.
Herpen discloses a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror (Figs. 1, 2, 3e-f, paras. [0030], [0043], [0071], [0073]-[0074], [0077]-[0079], [0085], [0091]-[0092], the element to be cleaned is arranged inside a circumferential hull 500 separate from the collector mirror 50, which is separated from the lithographic apparatus 1 to be placed in hull 500. Hull 500 additionally cleans other optical elements); and a gas supplier configured to supply a hydrogen gas along the surface of the condensing mirror and to the cleaning cell (Figs. 1, 2, 3e-f, paras. [0068], [0070]-[0071], [0078]-[0084], [0091]-[0092], gas source 700 supplies hydrogen containing gas in the hull 500 and along the collector mirror 50 when placed in the hull).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; and the gas supplier configured to supply the hydrogen gas along the surface of the condensing mirror and to the cleaning cell as taught by Herpen in the exposure apparatus as taught by Bykanov as modified by Yanagida since including a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; and the gas supplier configured to supply the hydrogen gas along the surface of the condensing mirror and to the cleaning cell is commonly used to provide an in situ or ex situ cleaning arrangement for cleaning a variety of optical elements to remove carbon or tin (Herpen, paras. [0008], [0085], [0092], [0096]).
Regarding claim 2, Bykanov as modified by Yanagida in view of Herpen discloses wherein the irradiator comprises an extreme ultraviolet (EUV) generating laser unit configured to irradiate an EUV generating laser (Bykanov, Figs. 1B-5, paras. [0027], [0029]-[0030], [0079], [0083], [0085]-[0083], [0090]-[0094], [0102], [0104]-[0107], [0110]-[0112], [0116], [0120]-[0121], [0124]-[0129], the system 21 produces a laser to generate EUV light), and a vacuum ultraviolet (VUV) generating laser unit configured to irradiate a VUV generating laser (Figs. 1B-5, paras. [0017], [0027], [0029]-[0030], [0042], [0058]-[0060], [0088], [0090]-[0093], [0105]-[0107], the cleaning system includes a laser that generates light with a wavelength below 70 nm),
wherein the controller is configured to cause the EUV generating laser unit to irradiate a pulsed EUV generating laser onto the target droplet during the exposure operation (Figs. 1B-5, paras. [0027], [0029]-[0030], [0079], [0083], [0085]-[0083], [0090]-[0094], [0102], [0104]-[0107], [0110]-[0112], [0114], [0116], [0120]-[0121], [0124]-[0129], the system 21 produces a laser to generate EUV light from irradiating target droplets of source material during exposure bursts), and
wherein the controller is configured to cause the VUV generating laser unit to irradiate a pulsed VUV generating laser onto the target droplet during a cleaning operation (Figs. 1B-5, paras. [0017], [0027], [0029]-[0030], [0058]-[0060], [0088], [0090]-[0093], [0105]-[0107], [0110], [0114], [0116], [0120]-[0124], [0124]-[0129], the cleaning system includes the laser that generates light with a wavelength below 70 nm in the second light radiator LPP to irradiate cleaning system target materials).
Regarding claim 3, Bykanov as modified by Yanagida in view of Herpen does not appear to explicitly describe wherein the controller is configured to control an intensity of the pulsed laser emitted during a cleaning operation to be less than an intensity of the pulsed laser emitted during the exposure operation, but Bykanov discloses wherein the controller is configured to control an intensity of the pulsed laser emitted during a cleaning operation to be different from an intensity of the pulsed laser emitted during the exposure operation (Figs. 1B-5, paras. [0051]-[0054], [0062], [0071], [0088]-[0096], [0099], [0106], [0112], [0116], [0126], the intensity output of the secondary light radiator during cleaning is different from the output for the primary EUV light radiator for substrate exposure). Since Bykanov discloses the general condition that the intensity is different between cleaning and exposure operations, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included wherein the intensity during the cleaning operation to be less than the intensity of the pulsed laser emitted during the exposure operation based on Bykanov’s teachings of different intensity during cleaning and exposure operations in the exposure apparatus as taught by Bykanov as modified by Yanagida in view of Herpen since including wherein the controller is configured to control an intensity of the pulsed laser emitted during a cleaning operation to be less than an intensity of the pulsed laser emitted during the exposure operation is commonly used to optimize efficient cleaning of the collector mirror while controlling the absorption of radiation (Bykanov, paras. [0010], [0058], [0093], [0099], [0124]).
Regarding claim 4, Bykanov as modified by Yanagida in view of Herpen does not appear to explicitly describe wherein the controller is configured to control a density of the target droplet supplied during a cleaning operation to be greater than a density of the target droplet supplied during the exposure operation, but Bykanov discloses wherein the controller is configured to control a density of the target droplet supplied during a cleaning operation to be different from a density of the target droplet supplied during the exposure operation (Figs. 1B-5, paras. [0093]-[095], [0100], [0110]-[0112], [0115], target material parameters are different during cleaning and exposure operations, including target repetition rate and droplet type). Since Bykanov discloses the general condition that the target droplet density is different between cleaning and exposure operations, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included wherein the controller is configured to control a density of the target droplet supplied during a cleaning operation to be greater than a density of the target droplet supplied during the exposure operation based on Bykanov’s teachings of different density during cleaning and exposure operations in the exposure apparatus as taught by Bykanov as modified by Yanagida in view of Herpen since including wherein the controller is configured to control a density of the target droplet supplied during a cleaning operation to be greater than a density of the target droplet supplied during the exposure operation is commonly used to generate the desired cleaning species to optimize efficient cleaning of the collector mirror while controlling the absorption of radiation (Bykanov, paras. [0010], [0058], [0093], [0100], [0110]-[0112], [0115], [0124]).
Regarding claim 5, Bykanov as modified by Yanagida in view of Herpen discloses wherein the controller is configured to cause the prepulse laser unit to irradiate the prepulse laser onto the target droplet in advance of the pulsed laser during the exposure operation (Bykanov, Figs. 1B-5, paras. [0076], [0083], [0091], [0094], [0106], [0110]-[0112], [0116], pre-pulses are supplied to the target material in advance of the main pulses during exposure bursts, and as modified by Yanagida, Figs. 1-2, 4-7, 9, 28, 30, 31, 36, 37, paras. [0094]-[0096], [0106], [0110], [0123], [0254], [0257], [0295]-[0296], [0300], [0306]-[0307], [0383], pre-pulse laser beam irradiates the droplet target to expand the target to produce pre-plasma prior to irradiation by the main pulse laser beam), and
wherein the controller is configured to cause the prepulse laser unit to refrain from irradiating the prepulse laser during the cleaning operation (Figs. 1B-5, paras. [0051], [0053]-[0059], [0061], [0070], [0085], [0093]-[0096], [0099]-[0100], [0103]-[0104], [0110]-[0112], [0120]-[0121], [0124], [0129], the cleaning pattern does not include prepulses).
Regarding claim 6, Bykanov as modified by Yanagida in view of Herpen does not appear to explicitly describe wherein the controller is configured to control a size of the target droplet supplied during a cleaning operation to be greater than a size of the target droplet supplied during the exposure operation, but Bykanov discloses wherein the controller is configured to control a size of the target droplet supplied during a cleaning operation to be different from a size of the target droplet supplied during the exposure operation (Figs. 1B-5, paras. [0091], [0093]-[0095], [0100], [0106], [0110]-[0112], [0115], [0121], target material parameters are different during cleaning and exposure operations, including target size). However, since Bykanov discloses the general conditions of different sizes of the target droplet supplied during the cleaning operation and the exposure operation, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included wherein the controller is configured to control a size of the target droplet supplied during a cleaning operation to be greater than a size of the target droplet supplied during the exposure operation based on Bykanov’s teachings of different target droplet sizes during cleaning and exposure operations in the exposure apparatus as taught by Bykanov as modified by Yanagida in view of Herpen since including wherein the controller is configured to control a size of the target droplet supplied during a cleaning operation to be greater than a size of the target droplet supplied during the exposure operation is commonly used to generate the desired cleaning species to optimize efficient cleaning of the collector mirror while controlling the absorption of radiation (Bykanov, paras. [0010], [0058], [0093], [0100], [0110]-[0112], [0115], [0124]).
Regarding claim 7, Bykanov as modified by Yanagida in view of Herpen discloses wherein the vacuum chamber comprises one or more ports through which an inside of the vacuum chamber is accessible by the droplet supplier, the irradiator, the gas supplier, the controller, and the exhaust pump (Bykanov, Figs. 1B-5, paras. [0048], [0072], [0083], [0085], [0087], [0094], [0104], [0108], [0110]-[0111], chamber 28 includes ports for a pulsed laser device 21, source material delivery system 90, gasses 28, 39, 39a, 39b, 39c, manifold 206, EUV controller 60, and pump 41 to control and form a plasma in chamber 28).
Regarding claim 8, Bykanov as modified by Yanagida in view of Herpen discloses wherein the EUV generating laser unit is configured to irradiate one of infrared and near-infrared wavelength lasers onto the target droplet (Bykanov, Figs. 1B-5, paras. [0072]-[0073], the laser system is a CO2 laser producing infrared wavelengths of 9.3 µm or 10.6 µm).
Regarding claim 9, Bykanov as modified by Yanagida in view of Herpen discloses wherein the VUV generating laser unit is configured to irradiate one of infrared wavelength laser, a visible light wavelength laser, and an ultraviolet ray wavelength laser onto the target droplet (Bykanov, Figs. 1B-5, paras. [0017], [0027], [0029]-[0030], [0042]-[0044], [0058]-[0060], [0072]-[0073], [0088]-[0093], [0105]-[0107], [0112]-[0114], the laser system in the secondary light radiator LPP in the cleaning system has a wavelength below 70 nm).
Regarding claim 12, Bykanov as modified by Yanagida in view of Herpen discloses wherein the controller is configured to change the supply condition of the target droplet and the irradiation condition of the pulsed laser to conditions different from the conditions during the exposure operation to remove a tin attached on a mirror from the mirror (Bykanov, Figs. 1B-5, paras. [0050]-[0051], [0053]-[0059], [0061], [0070], [0085], [0093]-[0096], [0099]-[0100], [0103]-[0104], [0120]-[0121], [0124], [0129], the EUV controller controls the laser and source material supply during a cleaning process in a cleaning period different from the exposure bursts to remove tin from the optic 24).
Regarding claim 13, Bykanov as modified by Yanagida in view of Herpen discloses wherein the controller is configured to control a wavelength of the pulsed laser emitted during a cleaning operation to be less than a wavelength of the pulsed laser emitted during the exposure operation (Bykanov, Figs. 1B-5, paras. [0058], [0071]-[0073], [0088]-[0093], [0105]-[0107], [0112]-[0114],the laser system 21 is a CO2 laser producing infrared wavelengths of 9.3 µm or 10.6 µm in the exposure bursts, and the secondary light radiator in the cleaning system includes a laser system that emits light with a wavelength below 125 nm or below 70 nm).
Regarding claim 14, Bykanov discloses an exposure apparatus (Figs. 1-5, para. [0046]) comprising:
a droplet supplier configured to supply a target droplet inside a vacuum chamber (Figs. 1-5, paras. [0083], [0102], [0108], [0110], [0113]-[0114], source material delivery system 90 provides droplets inside a vacuum chamber 26);
an irradiator configured to irradiate a pulsed laser onto the target droplet (Figs. 1-5, paras. [0017], [0027], [0029]-[0030], [0058]-[0060], [0071]-[0073], [0079], [0085], [0088], [0090]-[0093], [0105]-[0107], a pulsed laser device 21 irradiates the pulsed laser onto droplets at irradiation region 48);
a condensing mirror inside the vacuum chamber, the condensing mirror being configured to condense a light emitted from the target droplet by irradiation of the pulsed laser onto the target droplet (Figs. 1-5, paras. [0048]-[0049], [0065], [0071]-[0073], [0086], [0088], [0094], optic 24 is arranged in chamber 26 and condenses EUV radiation emitted by irradiating source material with laser pulses);
a gas supplier configured to supply a hydrogen gas along a surface of the condensing mirror (Figs. 1-5, paras. [0020], [0053]-[0055], [0057]-[0059], [0061], [0087], [0093], [0102], [0109], [0113], [0120]-[0121], [0129], gasses 28, 39, 39a, 39b, 39c, manifold 206 supply hydrogen gas along the surface of optic 24);
a controller (Fig. 1b, para. [0085], EUV controller 60) configured to change a supply condition of the target droplet and an irradiation condition of the pulsed laser to conditions different from conditions during an exposure operation to increase an amount of production of hydrogen radicals in the vacuum chamber (Figs. 1B-5, paras. [0051], [0053]-[0059], [0061], [0070], [0085], [0088]-[0096], [0099]-[0100], [0103]-[0106], [0112], [0116], [0120]-[0121], [0124]-[0129], EUV controller 60 controls the drive laser control system 65 to control the light pulses of pulsed laser device 21, and EUV controller 60 controls the droplet position, direction, timing, and droplet modulation of droplets from source material delivery system 90. The EUV controller controls the laser and source material supply during a cleaning process in a cleaning period different from the exposure bursts such that the cleaning species concentration of hydrogen radicals increases); and
an exhaust pump configured to exhaust a gas from an inside of the vacuum chamber (Figs. 1-5, paras. [0057], [0066], [0087], [0102], [0109], [0113], [0120]-[0121], [0128], pump 41 exhausts gas from the chamber 26), wherein the irradiator comprises:
an extreme ultraviolet (EUV) generating laser unit configured to emit an EUV generating laser during the exposure operation (Figs. 1B-5, paras. [0027], [0029]-[0030], [0046], [0052], [0071]-[0073], [0079], [0083], [0085]-[0088], [0090]-[0094], [0102], [0104]-[0107], [0110]-[0112], [0114], [0105]-[0106], the system 21 produces a laser to generate EUV light during exposure by exposure device 12); and
a vacuum ultraviolet (VUV) generating laser unit configured to emit a VUV generating laser (Figs. 1B-5, paras. [0017], [0027], [0029]-[0030], [0058]-[0060], [0088], [0090]-[0093], [0105]-[0107], the cleaning system includes a laser that generates light with a wavelength below 70 nm), and
a prepulse laser unit configured to irradiate a prepulse laser onto the target droplet in advance of the pulsed laser during the exposure operation to heat the target droplet and reduce a density of the target droplet (the limitation “to heat the target droplet and reduce a density of the target droplet” is functional language that recites the manner in which the claimed apparatus is operated and does not differentiate the claimed apparatus from the system taught by Bykanov. See MPEP 2114. Figs. 1B-5, paras. [0076], [0083], [0091], [0094], [0106], [0110]-[0112], [0116], pre-pulses are supplied in advance of the main pulses to the target droplet), and
wherein the controller is configured to cause the EUV generating laser unit to irradiate a pulsed EUV generating laser onto the target droplet during the exposure operation (Figs. 1B-5, paras. [0027], [0029]-[0030], [0079], [0083], [0085]-[0088], [0090]-[0094], [0102], [0104]-[0107], [0110]-[0112], [0114], [0105]-[0106], the system 21 produces a laser to generate EUV light from irradiating target droplets of source material during exposure bursts), and to cause the VUV generating laser unit to irradiate a pulsed VUV generating laser onto the target droplet during cleaning (Figs. 1B-5, paras. [0017], [0027], [0029]-[0030], [0058]-[0060], [0088]-[0093], [0096]-[0107], [0110], [0112]-[0114], [0116], [0118]-[0119], [0125]-[0129], the cleaning system includes the laser that generates light with a wavelength below 70 nm in the second light radiator LPP to irradiate cleaning system target materials). Bykanov does not appear to explicitly describe the prepulse laser being an Nd:YAG laser and a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; and the gas supplier configured to supply the hydrogen gas along the surface of the condensing mirror and to the cleaning cell.
Yanagida discloses wherein the irradiator comprises a prepulse laser unit configured to irradiate a prepulse laser onto the target droplet in advance of the pulsed laser during the exposure operation to heat the target droplet and reduce a density of the target droplet, the prepulse laser being an Nd:YAG laser (Figs. 1-2, 4-7, 9, 28, 30, 31, 36, 37, paras. [0094]-[0096], [0106], [0110], [0123], [0254], [0257], [0295]-[0296], [0300], [0306]-[0307], [0383], pre-pulse laser beam irradiates the droplet target to expand the target to produce pre-plasma, and the pre-pulse laser is a Nd:YAG laser).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included wherein the irradiator comprises a prepulse laser unit configured to irradiate a prepulse laser onto the target droplet in advance of the pulsed laser during the exposure operation to heat the target droplet and reduce a density of the target droplet, the prepulse laser being an Nd:YAG laser as taught by Yanagida in the irradiator in the exposure apparatus as taught by Bykanov since including wherein the irradiator comprises a prepulse laser unit configured to irradiate a prepulse laser onto the target droplet in advance of the pulsed laser during the exposure operation to heat the target droplet and reduce a density of the target droplet, the prepulse laser being an Nd:YAG laser is commonly used to improve conversion efficiency of converting laser beam energy to EUV light energy (Yanagida, paras. [0095]-[0096], [0254], [0257]).
Bykanov as modified by Yanagida does not appear to explicitly describe a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; and the gas supplier configured to supply the hydrogen gas along the surface of the condensing mirror and to the cleaning cell.
Herpen discloses a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror (Figs. 1, 2, 3e-f, paras. [0030], [0043], [0071], [0073]-[0074], [0077]-[0079], [0085], [0091]-[0092], the element to be cleaned is arranged inside a circumferential hull 500 separate from the collector mirror 50, which is separated from the lithographic apparatus 1 to be placed in hull 500. Hull 500 additionally cleans other optical elements); and a gas supplier configured to supply a hydrogen gas along the surface of the condensing mirror and to the cleaning cell (Figs. 1, 2, 3e-f, paras. [0068], [0070]-[0071], [0078]-[0084], [0091]-[0092], gas source 700 supplies hydrogen containing gas in the hull 500 and along the collector mirror 50 when placed in the hull).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; and the gas supplier configured to supply the hydrogen gas along the surface of the condensing mirror and to the cleaning cell as taught by Herpen in the exposure apparatus as taught by Bykanov as modified by Yanagida since including a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the condensing mirror; and the gas supplier configured to supply the hydrogen gas along the surface of the condensing mirror and to the cleaning cell is commonly used to provide an in situ or ex situ cleaning arrangement for cleaning a variety of optical elements to remove carbon or tin (Herpen, paras. [0008], [0085], [0092], [0096]).
Regarding claim 15, Bykanov as modified by Yanagida in view of Herpen discloses wherein the EUV generating laser unit is configured to irradiate one of infrared and near-infrared wavelength lasers onto the target droplet (Bykanov, Figs. 1B-5, paras. [0072]-[0073], the laser system is a CO2 laser producing infrared wavelengths of 9.3 µm or 10.6 µm to irradiate the droplets), and
wherein the VUV generating laser unit is configured to irradiate at least one of an infrared wavelength laser, a visible light wavelength laser, and an ultraviolet ray wavelength laser onto the target droplet (Figs. 1B-5, paras. [0017], [0027], [0029]-[0030], [0042]-[0044], [0058]-[0060], [0072]-[0073], [0088]-[0093], [0105]-[0107], [0112]-[0114], the laser system in the secondary light radiator LPP in the cleaning system has a wavelength below 70 nm to irradiate the droplets).
Regarding claim 16, Bykanov as modified by Yanagida in view of Herpen discloses wherein the controller is configured to cause the prepulse laser unit to irradiate the prepulse laser onto the target droplet in advance of the pulsed laser during the exposure operation (Bykanov, Figs. 1B-5, paras. [0076], [0083], [0091], [0094], [0106], [0110]-[0112], [0116], pre-pulses are supplied to the target material in advance of the main pulses during exposure bursts, and as modified by Yanagida, Figs. 1-2, 4-7, 9, 28, 30, 31, 36, 37, paras. [0094]-[0096], [0106], [0110], [0123], [0254], [0257], [0295]-[0296], [0300], [0306]-[0307], [0383], pre-pulse laser beam irradiates the droplet target to expand the target to produce pre-plasma prior to irradiation by the main pulse laser beam), and
wherein the controller is configured to cause the prepulse laser unit to refrain from irradiating the prepulse laser during a cleaning operation (Figs. 1B-5, paras. [0051], [0053]-[0059], [0061], [0070], [0085], [0093]-[0096], [0099]-[0100], [0103]-[0104], [0110]-[0112], [0120]-[0121], [0124], [0129], the cleaning pattern does not include prepulses).
Regarding claim 17, Bykanov as modified by Yanagida in view of Herpen discloses wherein the controller is configured to change the supply condition of the target droplet and the irradiation condition of the pulsed laser such that tin attached on the condensing mirror becomes SnH4 (Bykanov, Figs. 1B-5, paras. [0053]-[0059], [0061], [0070], [0085], [0088]-[0096], [0099]-[0100], [0103]-[0106], [0112], [0116], [0120]-[0121], [0124]-[0129], the tin attached to the optic and the hydrogen radicals produced by controlling the target droplets and irradiation forms tin hydride).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Bykanov as modified by Yanagida in view of Herpen as applied to claim 2 above, and further in view of Ueno et al. (US PGPub 2008/0087840, Ueno hereinafter).
Regarding claim 10, Bykanov as modified by Yanagida does not appear to explicitly describe wherein the EUV generating laser unit is configured to irradiate the EUV generating laser at an intensity of about 1010 W/cm2 to about 1011 W/cm2.
Ueno discloses wherein the EUV generating laser unit is configured to irradiate the EUV generating laser at an intensity of about 1010 W/cm2 to about 1011 W/cm2 (para. [0063], the laser beam has an intensity of up to 5 x 1010 W/cm2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included wherein the EUV generating laser unit is configured to irradiate the EUV generating laser at an intensity of about 1010 W/cm2 to about 1011 W/cm2 as taught by Ueno as the intensity of the EUV generating laser unit in the exposure apparatus as taught by Bykanov as modified by Yanagida since including wherein the EUV generating laser unit is configured to irradiate the EUV generating laser at an intensity of about 1010 W/cm2 to about 1011 W/cm2 is commonly used to obtain the desired EUV conversion efficiency while minimizing debris (Ueno, para. [0064]).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Bykanov as modified by Yanagida in view of Herpen as applied to claim 2 above, and further in view of Harris (US Patent No. 4,218,628).
Regarding claim 11, Bykanov as modified by Yanagida in view of Herpen does not appear to explicitly describe wherein the VUV generating laser unit is configured to irradiate the VUV generating laser at an intensity less than about 109 W/cm2.
Harris discloses wherein the VUV generating laser unit is configured to irradiate the VUV generating laser at an intensity less than about 109 W/cm2 (col. 7, lines 3-22, the laser has an intensity of 4.3 x 108 W/cm2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included wherein the VUV generating laser unit is configured to irradiate the VUV generating laser at an intensity less than about 109 W/cm2 as taught by Harris as the intensity of the VUV generating laser unit in the exposure apparatus as taught by Bykanov as modified by Yanagida in view of Herpen since including wherein the VUV generating laser unit is configured to irradiate the VUV generating laser at an intensity less than about 109 W/cm2 is commonly used to provide a vacuum ultraviolet source with improved output radiation (Harris, col. 2, lines 57-67).
Allowable Subject Matter
Claims 18-20 are allowed.
The following is a statement of reasons for the indication of allowable subject matter.
Regarding claim 18, the prior art of record, either alone or in combination, fails to teach or render obvious a light source target configured to supply any one or a mixture of xenon, argon, and nitrogen based on the driving laser irradiated on the light source target; a vacuum ultraviolet (VUV) condensing lens configured to condense plasma radiation emitted from the light source target; a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the VUV condensing lens; a hydrogen gas supplier configured to supply a hydrogen gas to the cleaning cell; and an exhaust pump configured to exhaust a gas from an inside of the cleaning cell, wherein the driving laser is irradiated from the driving laser unit onto the light source target to emit the plasma radiation from the light source target, and wherein the plasma radiation irradiated onto the hydrogen gas in the cleaning cell increases hydrogen radicals in the cleaning cell to remove a tin compound attached on a surface of the object for cleaning. These limitations in combination with the other limitations of claim 18 render the claim non-obvious over the prior art of record.
The dependent claims are likewise allowable by virtue of their dependency upon an allowable independent claim as stated above.
Bykanov discloses a vacuum chamber (Figs. 1-5, paras. [0071]-[0072], [0083], [0102], [0108], [0110], [0111], [0113]-[0114], [0131], a chamber 26 is a vacuum chamber); a driving laser unit configured to irradiate a driving laser (Figs. 1-5, paras. [0017], [0027], [0029]-[0030], [0058]-[0060], [0071]-[0073], [0079], [0085], [0088], [0090]-[0093], [0105]-[0107], a pulsed laser device 21 irradiates the pulsed laser); a light source target configured to supply material to a location in which the driving laser is condensed (Figs. 1-5, paras. [0083], [0102], [0108], [0110], [0113]-[0114], source material delivery system 90 provides droplets inside a vacuum chamber 26); a vacuum ultraviolet (VUV) condensing lens configured to condense a laser emitted from the light source target (Figs. 1-5, paras. [0048]-[0049], [0065], [0071]-[0073], [0086], [0088], [0094], optic 24 is arranged in chamber 26 and condenses EUV radiation emitted by irradiating source material with laser pulses); a hydrogen gas supplier configured to supply a hydrogen gas to the cleaning cell (Figs. 1-5, paras. [0020], [0053]-[0055], [0057]-[0059], [0061], [0087], [0093], [0102], [0109], [0113], [0120]-[0121], [0129], gasses 28, 39, 39a, 39b, 39c, manifold 206 supply hydrogen gas along the surface of optic 24); and an exhaust pump configured to exhaust a gas from an inside of the cleaning cell (Figs. 1-5, paras. [0057], [0066], [0087], [0102], [0109], [0113], [0120]-[0121], [0128], pump 41 exhausts gas from the chamber 26), wherein the driving laser is irradiated from the driving laser unit onto the light source target to emit the driving laser from the light source target (Figs. 1B-4, paras. paras. [0051], [0053]-[0059], [0061], [0070], [0085], [0088]-[0096], [0099]-[0100], [0103]-[0106], [0112], [0116], [0120]-[0121], [0124]-[0129], the cleaning system includes a secondary light radiator including a laser produced plasma of irradiating a target with a laser beam), and wherein the driving laser irradiated onto the hydrogen gas increases hydrogen radicals to remove a tin compound attached on a surface of the object for cleaning (Figs. 1B-5, paras. [0051], [0053]-[0059], [0061], [0070], [0085], [0088]-[0096], [0099]-[0100], [0103]-[0106], [0112], [0116], [0120]-[0121], [0124]-[0129], the EUV controller controls the laser and source material supply during a cleaning process in a cleaning period to produce hydrogen radicals to remove tin attached to the optic 24). Bykanov does not describe or suggest the light source target configured to supply any one or a mixture of xenon, argon, and nitrogen, and a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the VUV condensing lens.
Kuritsyn et al. (US PGPub 2014/0306115, Kuritsyn hereinafter) discloses a light source target configured to supply any one or a mixture of xenon, argon, and nitrogen to a location in which the driving laser is condensed (Fig. 1B, paras. [0026]-[0027], target material 102 includes xenon in the position in which the beam from excitation source 104 is condensed). Kuritsyn fails to describe or suggest a cleaning cell accommodating an object for cleaning, the cleaning cell being separate from the VUV condensing lens.
Ueno et al. (US PGPub 2010/0192973, Ueno hereinafter) discloses a cleaning cell a cleaning cell accommodating an object for cleaning (Figs. 16-20, paras. [0107]-[0112], [0117]-[0133], mirror cleaning chamber 31), wherein the cleaning cell further comprises an insertion port into which the object for cleaning is inserted to deliver the object for cleaning (Figs. 16-20, paras. [0107]-[0112], [0117]-[0133], the EUV collector mirror cleaning chamber 31 includes a gate valve 32 through which the EUV collector mirror 51 is moved for cleaning). Ueno 973 does not describe or render obvious a vacuum ultraviolet (VUV) condensing lens configured to condense plasma radiation emitted from the light source target; the cleaning cell being separate from the VUV condensing lens; a hydrogen gas supplier configured to supply a hydrogen gas to the cleaning cell; and an exhaust pump configured to exhaust a gas from an inside of the cleaning cell, wherein the driving laser is irradiated from the driving laser unit onto the light source target to emit the plasma radiation from the light source target, and wherein the plasma radiation irradiated onto the hydrogen gas in the cleaning cell increases hydrogen radicals in the cleaning cell to remove a tin compound attached on a surface of the object for cleaning.
Nikipelov et al. (US PGPub 2022/0205900, Nikipelov hereinafter) discloses a cleaning cell accommodating an object for cleaning, wherein the cleaning cell further comprises an opening transmitting plasma radiation emitted from the light source target onto an inside of the cleaning cell (Fig. 2, paras. [0056]-[0060], [0070], illumination source 110 is a laser-induced plasma source that outputs a radiation beam through window 111 into vacuum chamber 150 to mirrors 301 and 302). Nikipelov does not describe or render obvious a light source target configured to supply any one or a mixture of xenon, argon, and nitrogen based on the driving laser irradiated on the light source target; a vacuum ultraviolet (VUV) condensing lens configured to condense plasma radiation emitted from the light source target; the cleaning cell being separate from the VUV condensing lens; a hydrogen gas supplier configured to supply a hydrogen gas to the cleaning cell; and wherein the plasma radiation irradiated onto the hydrogen gas in the cleaning cell increases hydrogen radicals in the cleaning cell to remove a tin compound attached on a surface of the object for cleaning.
Banine et al. (US PGPub 2007/0069162) discloses a cleaning cell accommodating an object for cleaning (Figs. 7-8, paras. [0087]-[0105], cleaning device 600 includes a circumferential hull enclosing the collector assembly 209). Banine does not describe or render obvious a light source target configured to supply any one or a mixture of xenon, argon, and nitrogen based on the driving laser irradiated on the light source target; a vacuum ultraviolet (VUV) condensing lens configured to condense plasma radiation emitted from the light source target; the cleaning cell being separate from the VUV condensing lens; a hydrogen gas supplier configured to supply a hydrogen gas to the cleaning cell; wherein the driving laser is irradiated from the driving laser unit onto the light source target to emit the plasma radiation from the light source target, and wherein the plasma radiation irradiated onto the hydrogen gas in the cleaning cell increases hydrogen radicals in the cleaning cell to remove a tin compound attached on a surface of the object for cleaning.
Response to Arguments
Applicant’s arguments with respect to claims 1-17 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
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/CHRISTINA A RIDDLE/Primary Examiner, Art Unit 2882