DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 September 29, 2025 has been entered.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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, 4, 6-8, 10, 11, 13-16, and 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Buurman et al. [US 2013/0022901] in view of Singer et al. [US 2005/0274897].
For claims 1 and 14, Buurman teaches a system (see Figs. 2 and 6 and [0070]-[0076]) comprising:
at least two sensors (two or more sensors 264) of a lithographic apparatus, each configured to measure a value of property related to an illumination region provided for imaging a substrate by the lithographic apparatus; and
a processor (SOCTRL 242 and module 340) and configured to:
determine, based on a ratio of the measured values of the property as measured by one of the sensors in relation to the other (measured asymmetry profile 334 provided as a comparison between measured intensities, see [0074]), a drift of the illumination region (measured asymmetry profile 334 is the determined systematic drift and the asymmetry signal is fed back, see [0074]-[0077]);
determine, based on the drift of the illumination region, a drift in an attribute related to the illumination upstream of the illumination region measured by the at least two sensors (asymmetry in the intensity profile used to determine irregularities of the source, see [0061], [0064], [0070]-[0077]), and
determine, based on the drift in the attribute, a drift correction to be applied to the attribute to compensate for the drift in the attribute (non-uniformity correction to reduce asymmetry to zero, see [0072]-[0077]), and
initiate a signal to a device to apply the drift correction to the attribute to compensate for the drift in the attribute (signal ASX provided to source controller to optimize symmetry, see [0073], or other mechanisms, such as the UNICOM, see [0076]); and
at least a third sensor (sensors at the illumination system and sensors 264 at the reticle level monitor the intensity of the EUV radiation, see [0063], two or more of these sensors 264, more includes a third sensor, see [0073], sensors 264 distributed around the slit 330, are used for example to monitor the intensity of the source, individual sensors along the length of the slit are provided and used to detect non-uniformity along the slit, see [0072]) of the lithographic apparatus, the at least third sensor configured to measure an intensity of the illumination region for a determination other than, or in addition to, drift determination (monitor the intensity of the EUV radiation, and provide feedback to control module 242 where intensity can be controlled for example by modifying the quantity of fuel delivered in the stream 228, by adjusting the energy of the laser pulses, see [0063], control source power and used to detect non-uniformity along the slit, see [0072]).
Buurman fails to teach determining a drift of a central region the illumination region with respect to a reference position.
Singer teaches determining a drift of a central region the illumination region with respect to a reference position (misalignment shift from the null position, see Figs. 3a-3e and [0100]-[0112]).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide the determination of an illumination region misalignment by associating the intensity asymmetry with shift from an optimal position as taught by Singer in the determination of an asymmetry profile as taught by Buurman in order to indicate the direction and location of nonuniformity so that asymmetry can be more accurately corrected.
For claim 20, Buurman teaches a non-transitory computer readable medium having instructions therein, the instructions, when executed by a computer system (see [0078]), configured to cause the computer system at least:
receive, from each of at least two sensors, a measurement of value of a property related to an illumination region provided for imaging a substrate (two or more sensors 264 provide measurement to the comparison module 340, se Fig. 6);
determine, based on a ratio of the measured values (measured asymmetry profile 334 along the central portion of slit 330, see [0074]), a drift of the illumination region (measured asymmetry profile 334 is the determined systematic drift and asymmetry signal is fed back for control, see [0074]-[0077]); and
determine, based on the drift of the illumination region, a drift correction to be applied to an attribute related to the illumination to compensate for the drift (non-uniformity correction to reduce asymmetry to zero, see [0072]-[0077]);
initiate a signal to a device to apply the drift correction to the attribute to compensate for the drift in the attribute (signal ASX provided to source controller to optimize symmetry, see [0073], or other mechanisms, such as the UNICOM, see [0076]); and
receive, via at least a third sensor (sensors at the illumination system and sensors 264 at the reticle level monitor the intensity of the EUV radiation, see [0063], two or more of these sensors 264, more includes a third sensor, see [0073], sensors 264 distributed around the slit 330, are used for example to monitor the intensity of the source, individual sensors along the length of the slit are provided and used to detect non-uniformity along the slit, see [0072]), measurement of an intensity of the illumination region for a determination other than, or in addition to, drift determination (monitor the intensity of the EUV radiation, and provide feedback to control module 242 where intensity can be controlled for example by modifying the quantity of fuel delivered in the stream 228, by adjusting the energy of the laser pulses, see [0063], control source power and used to detect non-uniformity along the slit, see [0072]).
Buurman fails to teach determining a drift a central portion of the illumination region with respect to a reference position.
Singer teaches determining a drift a central portion of the illumination region with respect to a reference position (misalignment shift from the null position, see Figs. 3a-3e and [0100]-[0112]).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide the determination of an illumination region misalignment by associating the intensity asymmetry with shift from an optimal position as taught by Singer in the determination of an asymmetry profile as taught by Buurman in order to indicate the direction and location of nonuniformity so that asymmetry can be more accurately corrected.
For claim 4, Buurman teaches the drift in the attribute is caused by illumination optics collector contamination and/or an amount of power of an illumination source (see [0072]).
For claims 6 and 15, Buurman teaches the drift in the attribute is determined by conversion, based on a correlation between the drift of the illumination region and the drift in the attribute, the drift of the illumination region to the drift in the attribute (adjusting source errors by extrapolating source position using asymmetry profile to correct dose non-uniformity, see [0055]-[0056], [0061], [0063], [0072], and [0076]-[0077]).
For claims 7 and 16, Buurman teaches the at least two sensors comprises a first sensor located at a first location of the illumination region and a second sensor located at a second location of the illumination region (see Fig. 6).
For claim 8, Buurman teaches the first sensor is located at a first end of a uniformity compensator system and the second sensor is located at a second end of the uniformity compensator system (see [0056] and Fig. 6).
For claims 10 and 18, Buurman teaches the measured property value are illumination intensity values measured by a first sensor and a second sensor, respectively, of the at least two sensors (see [0070] and [0071]).
For claims 11 and 19, Buurman teaches the illumination region is an illumination slit (330, see Fig. 6).
For claim 13, Buurman teaches the reference position is at a center of an illumination slit (asymmetry 334 is through the center of the slit, see Fig. 6).
Claims 2, 3, 5, 9, 12, and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Buurman in view of Singer as applied to claims 1 and 14 above, and in further view of Zimmerman et al. [US 2010/0302525, US 6,455,862 and US 7,532,308 are incorporated by reference (see [0150])].
For claim 2, Buurman teaches the drift correction is determined using a uniformity compensator system (262, see [0055]-[0056], [0064], and [0076]-[0077]), wherein the uniformity compensator system comprises one or more uniformity compensators in one or more locations in a path of the illumination region to intercept one or more corresponding portions of the illumination region in the one or more locations (see Fig. 2), and determine, based on the drift of the illumination region or the drift in the attribute, an amount of adjustment to the one or more uniformity compensators to correct for the drift in the attribute (adjustment to correct non-uniformity by source control module extrapolation with given data, see [0055]-[0056], [0061], [0064], [0072], and [0076]-[0077]).
Buurman fails to teach using a uniformity sensitivity model embodied in the system is configured to determine adjustment.
Zimmerman teaches a uniformity sensitivity model embodied in the system is configured to determine adjustment (calculate positions of the uniformity correction device to compensate for drift, see Fig. 11 of the incorporated ‘308 Patent and [0141]-[0159] of Zimmerman).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide the uniformity sensitivity model as taught by Zimmerman in the adjustment of the compensator as taught by Buurman in order to determine the optimal position of the compensator.
For claim 3, Buurman fails to explicitly teaches the one or more uniformity compensators comprise one or more opaque finger members.
Zimmerman teaches the one or more uniformity compensators comprise one or more opaque finger members (see Fig. 7A).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide the uniformity compensators as taught by Zimmerman as the uniformity control module as taught by Buurman because the array of fingers provides selective control of the intensity profile.
For claims 5 and 12, Buurman teaches the reference position is an illumination slit position (330, see Fig. 6), but fails to explicitly teach determining the drift correction for each substrate within a lot and measuring at a start of an imaging of a substrate in a lot.
Zimmerman teaches determining the drift correction for each substrate within a lot and measuring at a start of an imaging of a substrate in a lot (measurement and correction of substrate 1-n in exposure of a lot, see Figs. 13-18).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide the correction sequence as taught by Zimmerman in the correction of exposure as taught by Buurman in order to ensure an accurate exposure for each substrate without unnecessary downtime to ensure throughput and quality.
For claims 9 and 17, Buurman teaches correcting the intensity distribution to provide uniform dose (see [0064], [0056], [0070], and [0072]), but fails to explicitly teach determining the drift is a dose drift with respect to a nominal dose, and the drift correction is a dose drift correction and/or the attribute is a pupil, wherein the drift in the attribute is a pupil drift with respect to a reference pupil, and the drift correction is a pupil drift correction.
Zimmerman teaches the drift is a dose drift with respect to a nominal dose, and the drift correction is a dose drift correction (calculation of corrections of intensity non-uniformity to ensure desired dose, see Fig. 4 and 5 and embodiments 6 and 7 and claims 1, 8 and 10 of the incorporated ‘862 Patent and [0141]-[0159] of Zimmerman) and/or the attribute is a pupil, wherein the drift in the attribute is a pupil drift with respect to a reference pupil, and the drift correction is a pupil drift correction.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide using the relationship between the intensity asymmetry and dose as taught by Zimmerman in the determination of the correction as taught by Buurman, because maintaining dose at a constant level reduces exposure error.
Response to Arguments
Applicant's arguments filed on September 9, 2025 have been fully considered but they are not persuasive.
The Applicant argues on pages 11 and 12, regarding claims 1, 14, and 20, that there is no apparent disclosure of at least third sensor configured to measure an intensity of the illumination region for a determination other than, or in addition to, drift determination in the cited portions of Buurman.
The Examiner respectfully disagrees. Buurman teaches in paragraph [0073] that there are two or more of these sensors 264 to detect asymmetry in the illumination at the patterning device. More than two sensors includes a third sensor. Buurman also teaches in paragraph [0063] that sensors 264 at the reticle level monitor the intensity of the EUV radiation, and provide feedback to control module 242 where intensity can be controlled by modifying the quantity of fuel delivered in the stream 228, particularly by adjusting the energy of the laser pulses. Accordingly, Buurman teaches at least three sensors that are used for detecting asymmetry and for determination of the desired energy of the light source, which is different than drift associated with asymmetry. Buurman also teaches in paragraph [0072], the sensors 264 may also be used for control source power, and also individual sensors along the length of the slit are provided and used to detect non-uniformity along the slit, and to apply corrections via the uniformity correction module.
Conclusion
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/Steven H Whitesell/Primary Examiner, Art Unit 1759