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 .
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 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Yang et al (U.S.Pat. 10,495,987) in view of Bykanov et al (US Patent Application Publication No. 2014/0110609).
With respect to claims 1, 10 and 19, Yang discloses the claimed EUV light source/lithography architecture including radiation source chamber (72) and controller (40). Yang further teaches controlling and changing operating conditions within the radiation source chamber between different modes, including changing gas flow between normal exposure and purge conditions (see col.4, lines 20-30; see figure 2 and the corresponding description). Yang also expressly teaches maintaining gas pressure in source vessel (72) during lithography operation. Yang does not expressly disclose changing the pressure in the radiation source chamber between first and second pressure setpoints differing at least by 10Pa.
Bykanov, however, expressly teaches an EUV light source in which chamber conditions are different during a burst period and an intervening period. More specifically, Bykanov teaches establishing a first gas pressure in the chamber during the burst period, and establishing a second gas pressure in the chamber, different from the first gas pressure, during the intervening period. Bykanov additionally teaches that the different operating periods are associated with EUV generation and in-situ cleaning of deposits form optics withing the EUV chamber. Bykanov explains the underlying contamination problem and the desirability of introducing cleaning species and removing volatile products from the vacuum chamber. It would have been obvious to one of ordinary skill in the art to modify the EUV source apparatus of Yang to establish different chamber pressures during different operating conditions, as expressly taught by Bykanov, because both references concern EUV source chambers and address control of chamber conditions for normal EUV operation and contamination/debris removal.
The modification merely applies Bykanov’s known techniques of changing chamber pressure between different operating periods to Yang’s EUV source chamber, yielding the predictable result of providing appropriate chamber conditions for the respective EUV generation and cleaning/purge operation.
Although Bykanov does not specifically disclose a pressure different exactly at least 10 Pa, Bykanov expressly requires the first and second chamber pressures to be different. One different chamber pressures are expressly taught for different operation conditions, the magnitude of the difference is an operating parameter to be selected according to the desired EUV generation, gas-flow, vacuum and cleaning conditions. It would therefore have been obvious to select the first and second pressure values, including values differing at least 10 Pa, through routine optimization of known chamber-pressure conditions for efficiency and contamination reduction, as intended by Yang.
As to claims 2-3, and 11-12, it would have been obvious to select operating temperature appropriate for the particular components, material and desired chamber condition through routine experimentation for efficiency and contamination reduction, as intended by Yang. 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. In re Aller, 105 USPQ 233.
As to claims 4, 5, 13 and 14, as discussed, Bykanov expressly establishes different pressures for different EUV chamber operating periods. Yang likewise recognizes pressure as an operating condition of its source vessel. Accordingly, selection of workable pressure values appropriate to normal condition and clean/purge operation would have constituted routine optimization of a known result-effective variable. Application has not established that recited ranges are critical or produce an unexpected result.
As to claims 6-8 and 15-17, Yang expressly teaches controller (40) controlling gas supply and exhaust flow rates and changing the gas flow rates between operating conditions according to measured debris concentration. Yang teaches increasing the gas-flow rates when debris exceeds an upper threshold and subsequently decreasing the gas-flow rates when debris falls below a lower threshold. Yang therefore expressly establishes first and second gas-flow operating settings. Its claims likewise describe changing gas flow from a low-flow setting to a high flow setting and thereafter from the high-flow setting to the low-flow setting.
As previously set forth, selection of the particular magnitude of the flow rate difference, including at least 0.5 slm, constitutes routine optimization of a known result-effective operating variable directed to debris removal and contamination control.
As claims 7, 16, 8, 17, the particular hydrogen/extra dry clean air flow ranges likewise represent optimization of the known gas flow conditions according to the desired purge/cleaning operation, absent evidence of criticality or unexpected results.
As claims 9, 18 and 20, Yang establishes condition-responsive operation rather than a rigid predetermined period schedule: purge operation is initiated in response to measured debris concentration exceeding an upper threshold and terminated after debris falls below a lower threshold. Thus, timing necessarily depends upon actual operating/contamination conditions rather than merely a fixed periodic interval. The actual interval between such condition-responsive changes would therefore vary depending upon system use, debris generation, contamination accumulation, maintenance conditions, and operating history.
It would have been obvious to select or permit such operating intervals, including irregular intervals within approximately 24-96 hours, according to the contamination condition and desired system performance, because operation timing is itself an optimization parameter associated with the known condition responsive purge/cleaning process.
Claims 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Yang et al (U.S.Patent 10,495,987) in view of Nagai et al (U.S.Pat. 10,764,986).
With respect to claims 1-3, 10-12 and 19, Yang discloses the claimed EUV light source/lithography architecture including radiation source chamber (72) and controller (40). Yang further teaches controlling and changing operating conditions within the radiation source chamber between different modes, including changing gas flow between normal exposure and purge conditions (see col.4, lines 20-30; see figure 2 and the corresponding description). Yang further recognizes pressure as an operation parameter associated with the EUV source apparatus. For example, Yang teaches maintaining gas pressure in source vessel (72) and teaches that operating characteristics can vary with pressure. Yang, however, does not expressly disclose changing the temperature in the radiation source chamber between first and second temperature setpoints differing by at least 50°C, as present recited.
Nagai teaches this feature in the same field of EUV light generation system. More particularly, Nagai discloses an EUV light generation chamber (11) having optical elements disposed within the chamber and a temperature control mechanism configured to control the temperature of such optical elements. Nagai’s temperature mechanism includes a temperature control element, power supply, temperature sensor, and temperature controller, with the controller controlling the supplied power based upon detected temperature. Nagai expressly recognizes temperature as a parameter affecting operation and performance. Nagai teaches that the total etching rate varies a function of temperature, rises as temperature increases from approximately 0°C to approximately 60°C, and changes again at temperature exceeding approximately 100°C. Nagai therefore controls temperature within selected target temperature ranges, including approximately 40°C to 120°C and approximately 60°C to 100°C, to obtain the desired etching/deposition characteristics and suppress contamination of optical elements. Nagai further teaches active heating and cooling of optical elements within the EUV chamber and expressly teaches cooling an optical element when its temperature exceeds the target temperature range. In view of such teaching, it would have been obvious to a skilled artisan before the effective filling date of the claimed invention to combine the teachings of Yang and Nagai to obtain the claimed invention as specified in claims of the present application. It would have been obvious to a skilled artisan before the effective filling date of the claimed invention to modify the EUV radiation source apparatus and controller of Yang to further control and change temperature within the radiation chamber in accordance tithe the temperature control teachings of Nagai. Both Yang and Nagai concern EUV light generation chambers and address maintaining desirable operating conditions and reducing contamination/debris affecting optical components. Such modification would have predictably provided improved control of contamination, deposition and/or cleaning conditions within the EUV source chamber. Neither Yang nor Nagai expressly disclose a first temperature set point and a second temperature set point differ at least 50°C or both above 230°C or the first temperature set point is from about 200°C to about 600°C, and the second temperature set point is from about 10°C to about -20°C, as recited in the claims. As discussed, Nagai expressly identifies temperature as an operational variable affecting etching/deposition performance and teaches operation over substantial temperature ranges, including 40°C -120°C. Thus, temperature was known in the art to be a result-effective variable. It would have been obvious to a skilled artisan to select appropriate first and second temperature settings, including separated by at least 50°C or both setpoints to be above 230°C as well as selecting specified ranges of the first temperature setpoint and the second temperature setpoint as claimed for the purpose of reducing contamination of the radiation chamber.
As to claims 4, 5, 13 and 14, as discussed, Nagai expressly establishes different temperatures for different EUV chamber operating periods. Yang likewise recognizes pressure as an operating condition of its source vessel. Accordingly, selection of workable pressure values appropriate to normal condition and clean/purge operation would have constituted routine optimization of a known result-effective variable. Application has not established that recited ranges are critical or produce an unexpected result.
As to claims 6-8 and 15-17, Yang expressly teaches controller (40) controlling gas supply and exhaust flow rates and changing the gas flow rates between operating conditions according to measured debris concentration. Yang teaches increasing the gas-flow rates when debris exceeds an upper threshold and subsequently decreasing the gas-flow rates when debris falls below a lower threshold. Yang therefore expressly establishes first and second gas-flow operating settings. Its claims likewise describe changing gas flow from a low-flow setting to a high flow setting and thereafter from the high-flow setting to the low-flow setting.
As previously set forth, selection of the particular magnitude of the flow rate difference, including at least 0.5 slm, constitutes routine optimization of a known result-effective operating variable directed to debris removal and contamination control.
As claims 7, 16, 8, 17, the particular hydrogen/extra dry clean air flow ranges likewise represent optimization of the known gas flow conditions according to the desired purge/cleaning operation, absent evidence of criticality or unexpected results.
As claims 9, 18 and 20, Yang establishes condition-responsive operation rather than a rigid predetermined period schedule: purge operation is initiated in response to measured debris concentration exceeding an upper threshold and terminated after debris falls below a lower threshold. Thus, timing necessarily depends upon actual operating/contamination conditions rather than merely a fixed periodic interval. The actual interval between such condition-responsive changes would therefore vary depending upon system use, debris generation, contamination accumulation, maintenance conditions, and operating history.
It would have been obvious to select or permit such operating intervals, including irregular intervals within approximately 24-96 hours, according to the contamination condition and desired system performance, because operation timing is itself an optimization parameter associated with the known condition responsive purge/cleaning process.
Response to Amendment/Arguments
Applicant’s amendment filed August 4, 2026 has been entered. Claims 1, 6-10, 15-20 have been amended. Applicant’s arguments in conjunction with the amendment have been carefully reviewed but have been traversed in view of new grounds of rejections as set forth above.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
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HUNG HENRY NGUYEN
Primary Examiner
Art Unit 2882
Hvn
8/28/26
/HUNG V NGUYEN/Primary Examiner, Art Unit 2882
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