DETAILED ACTION
Response to Arguments
Applicant's arguments filed 1/28/2026 have been fully considered but they are not persuasive.
Applicant argues that the combination does not teach or disclose filtering the byproduct metal outside the droplet generator. Examiner disagrees as Dijksman discloses providing a main filter 315 for filtering fuel from the reservoir 310 (see paragraph [0038] of Dijksman), which is separate from the droplet generator 300. In light of that teaching, the combination of Hergenhan and Dijksman would provide the filter between the vessels 24 of unused metal/debris and the droplet generator 63, which would be outside the droplet generator 63 (see Fig. 2 of Hergenhan).
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 1-16 are rejected under 35 U.S.C. 103 as being unpatentable over Hergenhan et al. (US PGPub 2008/0006783, hereinafter Hergenhan) in view of Dijksman et al. (WO 2017/102261, hereinafter Dijksman).
Regarding claim 1, Fig. 2 of Hergenhan discloses a method of generating EUV radiation (EUV radiation based on a plasma that is generated by electric discharge, see paragraph [0003]) comprising:
generating metal droplets with a droplet generator (droplets of a droplet flow 62 of emitter material which is supplied from a droplet generator 63, see paragraph [0047]);
generating the EUV radiation by exposing metal droplets to an excitation laser (plasma generation 6 is defined by the evaporation of individual droplets of a droplet flow 62 of emitter material (e.g. tin, a metal) in that a pulsed laser beam 52 (e.g. excitation laser) evaporates the emitter material, see paragraph [0047]);
collecting a metal including one or more of excess metal droplets and metal debris produced when generating the metal droplets and the EUV radiation (droplets of the droplet flow 62 are directed to vessels 24 or 25 to recycle emitter material that is not evaporated (e.g. debris or excess material), see paragraph [0056]); and
reusing the collected metal to generate additional metal droplets (unused droplets are recycled, see paragraph [0056]).
Hergenhan fails to teach the collected metal for additional metal droplets are filtered.
Dijksman discloses a droplet generator with one or more additional filters between the main filter (located in the fuel reservoir 310) and the nozzle (see paragraph [0038]). Dijksman teaches a filter is advantageously used to prevent contamination in the fuel from forming a clog in the nozzle (see paragraph [0037]).
Dijksman modifies Hergenhan by suggesting providing a filter in the reservoir outside the droplet generator leading to the droplet generator.
Since both inventions are drawn to forming EUV radiation from a liquid metal droplet, it would have been obvious to the ordinary artisan before the effective filing date to modify Hergenhan by providing one or more additional filters between the reservoir and the nozzle for the purpose of preventing contamination in the fuel from forming a clog in the nozzle as taught by Dijksman.
Regarding claim 2, Hergenhan discloses collecting the metal includes collecting the excess metal droplets and the metal debris (droplets of the droplet flow 62 are directed to vessels 24 or 25 to recycle emitter material that is not evaporated (e.g. debris or excess material), see paragraph [0056]).
Regarding claim 3, Hergenhan fails to disclose the excess metal droplets are collected separately from the metal debris.
Dijksman discloses a droplet generator with one or more additional filters between the main filter (located in the fuel reservoir 310) and the nozzle (see paragraph [0038]). Dijksman teaches a filter is advantageously used to prevent contamination in the fuel from forming a clog in the nozzle (see paragraph [0037]). The main filter 315 (located in the reservoir) filters the majority of the larger contaminating particles (i.e. debris, see paragraph [0041]) and the first nozzle filter 345 (located in the nozzle, see paragraph [0041]) further filters contaminants from the liquid metal material as the material collects in the nozzle for generating further droplets from the nozzle.
Dijksman modifies Hergenhan by suggesting providing filters in the reservoir and the nozzle of the droplet generator.
Since both inventions are drawn to forming EUV radiation from a liquid metal droplet, it would have been obvious to the ordinary artisan before the effective filing date to modify Hergenhan by providing one or more additional filters between the reservoir and the nozzle for the purpose of preventing contamination in the fuel from forming a clog in the nozzle as taught by Dijksman.
Regarding claim 4, Hergenhan fails to disclose the filtering the collected metal comprises filtering the metal of the metal droplets separately from filtering the metal of the metal debris.
Dijksman discloses a droplet generator with one or more additional filters between the main filter (located in the fuel reservoir 310) and the nozzle (see paragraph [0038]). Dijksman teaches a filter is advantageously used to prevent contamination in the fuel from forming a clog in the nozzle (see paragraph [0037]). The main filter 315 (located in the reservoir) filters the majority of the larger contaminating particles (i.e. debris, see paragraph [0041]) and the first nozzle filter 345 (located in the nozzle, see paragraph [0041]) further filters contaminants from the liquid metal material as the material collects in the nozzle for generating further droplets from the nozzle.
Dijksman modifies Hergenhan by suggesting providing filters in the reservoir and the nozzle of the droplet generator.
Since both inventions are drawn to forming EUV radiation from a liquid metal droplet, it would have been obvious to the ordinary artisan before the effective filing date to modify Hergenhan by providing one or more additional filters between the reservoir and the nozzle for the purpose of preventing contamination in the fuel from forming a clog in the nozzle as taught by Dijksman.
Regarding claim 5, Hergenhan fails to disclose filtering of metal of the metal droplets comprises two filtration stages.
Dijksman discloses a droplet generator with two or more filters between the main filter (located in the fuel reservoir 310) and the nozzle (see paragraph [0038]). Dijksman teaches a filter is advantageously used to prevent contamination in the fuel from forming a clog in the nozzle (see paragraph [0037]). The main filter 315 (located in the reservoir) filters the majority of the larger contaminating particles (i.e. debris, see paragraph [0041]) and the first nozzle filter 345 (located in the nozzle, see paragraph [0041]) further filters contaminants from the liquid metal material as the material collects in the nozzle for generating further droplets from the nozzle.
Dijksman modifies Hergenhan by suggesting providing multiple filters in the reservoir and the nozzle of the droplet generator.
Since both inventions are drawn to forming EUV radiation from a liquid metal droplet, it would have been obvious to the ordinary artisan before the effective filing date to modify Hergenhan by providing one or more additional filters between the reservoir and the nozzle for the purpose of preventing contamination in the fuel from forming a clog in the nozzle as taught by Dijksman.
Regarding claim 6, Hergenhan fails to disclose filtering the collected metal of the metal debris comprises two filtration stages.
Dijksman discloses a droplet generator with two or more filters between the main filter (located in the fuel reservoir 310) and the nozzle (see paragraph [0038]). Dijksman teaches a filter is advantageously used to prevent contamination in the fuel from forming a clog in the nozzle (see paragraph [0037]). The main filter 315 (located in the reservoir) filters the majority of the larger contaminating particles (i.e. debris, see paragraph [0041]) and the first nozzle filter 345 (located in the nozzle, see paragraph [0041]) further filters contaminants from the liquid metal material as the material collects in the nozzle for generating further droplets from the nozzle. Dijksman teaches that additional filters can be provided to allow for more filtration (see paragraph [0039]).
Dijksman modifies Hergenhan by suggesting providing filters in the reservoir and the nozzle of the droplet generator.
Since both inventions are drawn to forming EUV radiation from a liquid metal droplet, it would have been obvious to the ordinary artisan before the effective filing date to modify Hergenhan by providing one or more additional filters between the reservoir and the nozzle for the purpose of preventing contamination in the fuel from forming a clog in the nozzle as taught by Dijksman.
Regarding claim 7, Hergenhan teaches the storing the collected metal at a temperature above the melting point of the collected metal before recycling the collected metal to generate additional metal droplets to the droplet generator (first and second vessels 24 and 25 for molten metal, see paragraph [0045]; unused droplets are directed into first and second vessels 24 and 25, see paragraph [0056] for use with the droplet generator 63, see paragraph [0047]).
Regarding claim 8, Hergenhan discloses a method of generating EUV radiation (EUV radiation based on a plasma that is generated by electric discharge, see paragraph [0003]) comprising:
dispensing metal droplet using a droplet generator (droplets of a droplet flow 62 of emitter material which is supplied from a droplet generator 63, see paragraph [0047]);
exposing the metal droplets to an excitation laser to generate EUV radiation (plasma generation 6 is defined by the evaporation of individual droplets of a droplet flow 62 of emitter material (e.g. tin, a metal) in that a pulsed laser beam 52 (e.g. excitation laser) evaporates the emitter material, see paragraph [0047]);
collecting excess metal droplets in a droplet catcher (droplets of the droplet flow 62 are directed to vessels 24 or 25 to recycle emitter material that is not evaporated (e.g. debris or excess material), see paragraph [0056]);
recycling the metal of the collected excess metal droplets to generate additional metal droplets at the droplet generator (unused droplets are recycled, see paragraph [0056]; for use with the droplet generator 63, see paragraph [0047]).
Hergenhan fails to teach the collected metal for additional metal droplets are filtered.
Dijksman discloses a droplet generator with one or more additional filters between the main filter (located in the fuel reservoir 310) and the nozzle (see paragraph [0038]). Dijksman teaches a filter is advantageously used to prevent contamination in the fuel from forming a clog in the nozzle (see paragraph [0037]).
Dijksman modifies Hergenhan by suggesting providing a filter in the reservoir outside the droplet generator leading to the droplet generator.
Since both inventions are drawn to forming EUV radiation from a liquid metal droplet, it would have been obvious to the ordinary artisan before the effective filing date to modify Hergenhan by providing one or more additional filters between the reservoir and the nozzle for the purpose of preventing contamination in the fuel from forming a clog in the nozzle as taught by Dijksman.
Regarding claim 9, the combination of Hergenhan and Dijksman discloses storing the filtered metal at a temperature above the melting point of the metal before recycling the filtered metal to the droplet generator (molten tin collects in the nozzle after the first nozzle filter 345 before being ejected as additional droplets, see Dijksman paragraph [0041]).
Regarding claim 10, Hergenhan discloses storing the metal at a temperature above the melting point of the metal before filtering the metal (first and second vessels 24 and 25 for molten metal, see paragraph [0045]).
Regarding claim 11, Hergenhan discloses storing the metal of the collected excess metal droplets at a temperature above the melting point of the metal before recycling the metal to the droplet generator (first and second vessels 24 and 25 for molten metal, see paragraph [0045]; unused droplets are directed into first and second vessels 24 and 25 and recycled for additional droplets, see paragraph [0056]).
Regarding claim 12, Hergenhan discloses capturing metal debris produced by the generation of the EUV radiation (droplets of the droplet flow 62 are directed to vessels 24 or 25 to recycle emitter material that is not evaporated (e.g. debris or excess material), see paragraph [0056]).
Regarding claim 13, Hergenhan discloses recycling a metal of the captured metal debris to generate additional metal droplets (unused droplets are recycled, see paragraph [0056]).
Hergenhan fails to teach the collected metal for additional metal droplets are filtered.
Dijksman discloses a droplet generator with one or more additional filters between the main filter (located in the fuel reservoir 310) and the nozzle (see paragraph [0038]). Dijksman teaches a filter is advantageously used to prevent contamination in the fuel from forming a clog in the nozzle (see paragraph [0037]).
Dijksman modifies Hergenhan by suggesting providing a filter in the reservoir outside the droplet generator leading to the droplet generator.
Since both inventions are drawn to forming EUV radiation from a liquid metal droplet, it would have been obvious to the ordinary artisan before the effective filing date to modify Hergenhan by providing one or more additional filters between the reservoir and the nozzle for the purpose of preventing contamination in the fuel from forming a clog in the nozzle as taught by Dijksman.
Regarding claim 14, Hergenhan fails to disclose the metal of the collected excess metal droplets and the metal of the captured metal debris are both filtered through a first filter.
Dijksman discloses a droplet generator with one or more additional filters between the main filter (located in the fuel reservoir 310) and the nozzle (see paragraph [0038]). Dijksman teaches a filter is advantageously used to prevent contamination in the fuel from forming a clog in the nozzle (see paragraph [0037]). The main filter 315 (located in the reservoir) filters the majority of the larger contaminating particles (i.e. debris, see paragraph [0041])
Dijksman modifies Hergenhan by suggesting providing a filter in the reservoir of the droplet generator.
Since both inventions are drawn to forming EUV radiation from a liquid metal droplet, it would have been obvious to the ordinary artisan before the effective filing date to modify Hergenhan by providing one or more additional filters between the reservoir and the nozzle for the purpose of preventing contamination in the fuel from forming a clog in the nozzle as taught by Dijksman.
Regarding claim 15, Hergenhan fails to disclose the metal of the collected excess metal droplets and the metal of the captured metal debris are filtered through different filters.
Dijksman discloses a droplet generator with one or more additional filters between the main filter (located in the fuel reservoir 310) and the nozzle (see paragraph [0038]). Dijksman teaches a filter is advantageously used to prevent contamination in the fuel from forming a clog in the nozzle (see paragraph [0037]). The main filter 315 (located in the reservoir) filters the majority of the larger contaminating particles (i.e. debris, see paragraph [0041]) and the first nozzle filter 345 (located in the nozzle, see paragraph [0041]) further filters contaminants from the liquid metal material as the material collects in the nozzle for generating further droplets from the nozzle.
Dijksman modifies Hergenhan by suggesting providing filters in the reservoir and the nozzle of the droplet generator.
Since both inventions are drawn to forming EUV radiation from a liquid metal droplet, it would have been obvious to the ordinary artisan before the effective filing date to modify Hergenhan by providing one or more additional filters between the reservoir and the nozzle for the purpose of preventing contamination in the fuel from forming a clog in the nozzle as taught by Dijksman.
Regarding claim 16, Hergenhan discloses a method of generating EUV radiation (EUV radiation based on a plasma that is generated by electric discharge, see paragraph [0003]) comprising:
discharging metal droplets from a droplet generator (droplets of a droplet flow 62 of emitter material which is supplied from a droplet generator 63, see paragraph [0047]);
irradiating the metal droplets with a laser to generate EUV radiation (EUV radiation based on a plasma that is generated by electric discharge, see paragraph [0003]; evaporation of individual droplets in a pulsed laser beam (e.g. excitation laser), see paragraph [0047]);
collecting with a EUV vessel a byproduct metal produced during the generation of the EUV radiation (droplets of the droplet flow 62 are directed to vessels 24 or 25 to recycle emitter material that is not evaporated (e.g. debris or excess material), see paragraph [0056]); and
recycling the byproduct metal to generate additional metal droplets (unused droplets are recycled, see paragraph [0056]).
Hergenhan fails to teach the collected metal for additional metal droplets are filtered.
Dijksman discloses a droplet generator with one or more additional filters between the main filter (located in the fuel reservoir 310) and the nozzle (see paragraph [0038]). Dijksman teaches a filter is advantageously used to prevent contamination in the fuel from forming a clog in the nozzle (see paragraph [0037]).
Dijksman modifies Hergenhan by suggesting providing a filter in the reservoir outside the droplet generator leading to the droplet generator.
Since both inventions are drawn to forming EUV radiation from a liquid metal droplet, it would have been obvious to the ordinary artisan before the effective filing date to modify Hergenhan by providing one or more additional filters between the reservoir and the nozzle for the purpose of preventing contamination in the fuel from forming a clog in the nozzle as taught by Dijksman.
Claims 17-20 are rejected under 35 U.S.C. 103 as being unpatentable over Hergenhan in view of Dijksman and in further view of Umeda et al. (WO 2016/103456, hereinafter Umeda).
Regarding claim 17, the combination of Hergenhan and Dijksman fails to disclose passing the byproduct metal through a conduit heated to a temperature higher than the melting point of the byproduct metal before filtering the byproduct metal.
Umeda teaches a pipe 722 connected to a tank 261, both connected to respective heaters (heater 711 may heat the tank 261 to a temperature equal to or higher than the melting point of the target 27 (i.e. tin); pipe 722 may connect to tank 261 and a heater (not shown) may be installed in the pipe to be kept at the same temperature as the tank 261).
Umeda modifies the combination of Hergenhan and Dijksman by suggesting a heater be provided between the reservoir and the nozzle.
Since all inventions are drawn to EUV generation, it would have been obvious to the ordinary artisan before the effective filing date to modify the combination of Hergenhan and Dijksman by providing a heater between the reservoir and the nozzle for the purpose of maintaining the temperature of the material equal to or above the melting point of the target to ensure the material stays in a molten state to prevent a blockage from forming.
Regarding claim 18, the combination of Hergenhan and Dijksman discloses storing the byproduct metal at a temperature above the melting point of the byproduct metal after filtering the byproduct metal (molten tin collects in the nozzle after the first nozzle filter 345 before being ejected as additional droplets, see Dijksman paragraph [0041]).
Regarding claim 19, Hergenhan discloses storing the byproduct metal at a temperature above the melting point of the byproduct metal before filtering the byproduct metal (first and second vessels 24 and 25 for molten metal, see paragraph [0045]).
Regarding claim 20, Hergenhan discloses storing the byproduct metal at a temperature above the melting point of the filtered byproduct metal before reusing the byproduct metal to regenerate the additional metal droplets (first and second vessels 24 and 25 for molten metal, see paragraph [0045]; unused droplets are directed into first and second vessels 24 and 25 and recycled for additional droplets, see paragraph [0056]; filtering as discussed in the combination above).
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to HANWAY CHANG whose telephone number is (571)270-5766. The examiner can normally be reached Monday - Friday 7:30 AM - 4:00 PM EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Georgia Epps can be reached at (571) 272-2328. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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Hanway Chang
/HC/ Examiner, Art Unit 2878
/GEORGIA Y EPPS/ Supervisory Patent Examiner, Art Unit 2878
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