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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 March 16, 2026 has been entered.
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 16-18, 23-25, 27, 28, and 30-35 are rejected under 35 U.S.C. 103 as being unpatentable over Van De Kerkhof et al. [US 2011/0164228] in view of Chen et al. [US 2019/0067203].
For claims 16 and 23, Van De Kerkhof teaches a method of metrology comprising:
measuring at least one surrounding observable parameter relating to a surrounding signal contribution to a metrology signal that comprises a contribution to the metrology signal that is not attributable to at least one target (obtaining Fourier transform data, see [0054]-[0065] and Figs. 5 and 6);
determining a correction from the surrounding signal observable parameter (interpolating or identifying Fourier transform of the product in steps S3 or S12);
obtaining first measurement data relating to measurement of one or more targets using measurement radiation forming a measurement spot on one or more of the one or more targets that is larger than one of the targets (the radiation is focused on the target, there will additionally be diffraction from the surrounding pattern, see [0053]); and
applying the correction to the first measurement data (subtracting Fourier transform ascribed to surrounding product in steps S4 and S14).
Van De Kerkhof fails to teach a first subset of the first measurement data relates to one or metrology targets and a second subset of the measurement data relates to one or more non-visible targets that are invisible to the metrology tool measuring the non-visible target; and the correction is determined from a metrology signal value for a non-visible target region of interest corresponding to the non-visible target within measurement images of the non-visible target.
Chen teaches a first subset of the first measurement data relates to one or metrology targets and a second subset of the measurement data relates to one or more non-visible targets that are invisible to the metrology tool measuring the non-visible target (the brightness of the image data corresponding to the dummy structure DS is different from the brightness of the image data corresponding to the overlay targets the metrology target 104, see [0053], [0056], [0058], [0067], [0069], [0074], and [0079]); and
the correction is determined from a metrology signal value for a non-visible target region of interest corresponding to the non-visible target within measurement images of the non-visible target (the processor 106 can distinguish the image data corresponding to the dummy structure DS and the image data corresponding to the overlay targets of the metrology target 104 and analyze the image data corresponding to the overlay targets of the metrology target 104 correctly, see [0053], [0056], [0058], [0067], [0069], [0074], and [0079]).
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 dummy structures and processing a target image as taught by Chen in the removal of noise as taught by Van De Kerkhof in order to ensure reduced cross talk and increase measurement accuracy.
For claim 27, Van De Kerkhof teaches a metrology apparatus (see Fig. 4), comprising:
a support for a substrate comprising one or more targets (support inherent to hold the substrate W, see Fig. 4);
an optical system (collection branch for measuring the target on the substrate, see Fig. 4) for measuring each target;
a processor (data processor, see [0059]) configured to control the metrology apparatus to perform a method comprising:
measuring at least one surrounding observable parameter relating to a surrounding signal contribution to a metrology signal that comprises a contribution to the metrology signal that is not attributable to at least one of the one or more targets (obtaining Fourier transform data, see [0054]-[0065] and Figs. 5 and 6);
determining a correction from the surrounding signal observable parameter (interpolating or identifying Fourier transform of the product in steps S3 or S12);
obtaining first measurement data relating to measurement of the one or more targets using measurement radiation forming a measurement spot on one or more of the one or more targets that is larger than one of the targets (the radiation is focused on the target, there will additionally be diffraction from the surrounding pattern, see [0053]); and
applying the correction to the first measurement data (subtracting Fourier transform ascribed to surrounding product in steps S4 and S14).
Van De Kerkhof fails to teach a first subset of the first measurement data relates to one or metrology targets and a second subset of the measurement data relates to one or more non-visible targets that are invisible to the metrology tool measuring the non-visible target; and the correction is determined from a metrology signal value for a non-visible target region of interest corresponding to the non-visible target within measurement images of the non-visible target.
Chen teaches a first subset of the first measurement data relates to one or metrology targets and a second subset of the measurement data relates to one or more non-visible targets that are invisible to the metrology tool measuring the non-visible target (the brightness of the image data corresponding to the dummy structure DS is different from the brightness of the image data corresponding to the overlay targets the metrology target 104, see [0053], [0056], [0058], [0067], [0069], [0074], and [0079]); and
the correction is determined from a metrology signal value for a non-visible target region of interest corresponding to the non-visible target within measurement images of the non-visible target (the processor 106 can distinguish the image data corresponding to the dummy structure DS and the image data corresponding to the overlay targets of the metrology target 104 and analyze the image data corresponding to the overlay targets of the metrology target 104 correctly, see [0053], [0056], [0058], [0067], [0069], [0074], and [0079]).
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 dummy structures and processing a target image as taught by Chen in the removal of noise as taught by Van De Kerkhof in order to ensure reduced cross talk and increase measurement accuracy.
For claim 17, Van De Kerkhof teaches the surrounding signal contribution comprises a contribution attributable to surrounding structure captured in the measurement spot when measuring the at least one target (the radiation is focused on the target, there will additionally be diffraction from the surrounding pattern, see [0053]).
For claim 18, Van De Kerkhof teaches wherein the at least one surrounding signal observable parameter comprises one or more of: a signal strength or intensity metric corresponding to the surrounding structure (lower intensity scattering from the surrounding patterns, see [0059]); an amplitude of an interference pattern corresponding to the surrounding structure; an aligned position and/or fringe position corresponding to the surrounding structure; an asymmetry corresponding to the surrounding structure; an intensity imbalance corresponding to the surrounding structure (lower intensity scattering from the surrounding patterns, see [0059]); a fringe visibility corresponding to the surrounding structure; and a difference between aligned positions for different colors corresponding to the surrounding structure.
For claim 24, Van De Kerkhof teaches the first measurement data comprises one or both of: post-exposure measurements; and pre-exposure measurements or alignment measurements (overlay errors, see [0044]).
For claim 25, Van De Kerkhof teaches a non-transitory computer readable medium storing a computer program comprising non-transitory processor readable instructions that, when run on suitable processor controlled apparatus, causes the processor controlled apparatus to perform the method of claim 16 (see [0081]).
For claim 28, Van De Kerkhof teaches a lithographic apparatus (see Fig. 1 and [0037]) comprising: an illumination system (IL) configured to condition a radiation beam; a patterning device support (MT) constructed to support a patterning device, the patterning device is capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam; a substrate table (WT, see [0037]) constructed to hold a substrate; a projection system (PS) configured to project the patterned radiation beam onto a target portion of the substrate; and at least one metrology apparatus (see Figs. 3 and 4) of claim 27.
For claim 30, Van De Kerkhof teaches the at least one metrology apparatus comprises a post-exposure metrology apparatus for performing post-exposure measurements on a substrate exposed with structures using the lithographic apparatus (post-lithography overlay measurement, see [0044]).
For claims 31-35, Van De Kerkhof fails to teach the one or more non-visible targets comprises a target having a form similar to a corresponding metrology target, the one or more non-visible targets comprises a grating having a period generating diffraction orders undetected by the metrology tool, wherein the one or more non-visible targets comprises a target having a reflective portion.
Chen teaches the one or more non-visible targets comprises a target having a form similar to a corresponding metrology target (DS structure similar to the , see Figs. 7C and 7D), the one or more non-visible targets comprises a grating having a period generating diffraction orders undetected by the metrology tool (period of the dummy components are greater than or less than the respective minimum or maximum working wavelength of the metrology system, thereby providing diffraction orders outside the numerical aperture, see [0070]-[0079]), wherein the one or more non-visible targets comprises a target having a reflective portion (dummy structure made of the same material as the gratings that light reflects from, see Fig. 1 and [0043]).
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 dummy structure as taught by Chen in the removal of noise as taught by Van De Kerkhof in order to more easily gather target data from metrology targets.
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 19-22 and 29 are rejected under 35 U.S.C. 103 as being unpatentable over Van De Kerkhof in view of Chen as applied to claims 16 and 28 above, and in further view of Smilde et al. [US 2012/0242970].
For claims 19-21, Van De Kerkhof teaches determining the correction as at least one correction relationship between at least one surrounding observable parameter and the surrounding signal contribution (obtaining Fourier transform data and interpolating or identifying Fourier transform of the product in steps S1-S3 or S11-S12, see [0054]-[0065] and Figs. 5 and 6).
Van De Kerkhof fails to teach the steps of measuring at least one surrounding observable parameter and determining a correction are performed in an initial calibration phase; and the calibration phase further comprises: determining the correction as at least one correction relationship between at least one surrounding observable parameter and the surrounding signal contribution in the calibration phase, wherein the determining at least one correction relationship comprises determining correction relationships for each of a plurality of different nominal stacks and/or illumination conditions of the measurement radiation, comprising obtaining calibration measurement data comprising calibration target data and corresponding calibration surrounding observable parameter data.
Smilde teaches the steps of measuring at least one surrounding observable parameter (collect calibration measurement, see [0085], measurement includes surrounding features, see Figs. 5, 8(a),8(b), 10 and [0065]) and determining a correction are performed in an initial calibration phase (correction for neighboring structures with implementations 1 and 2, see [0111]); and the calibration phase further comprises: determining a correction in the calibration phase (corrections to remove contributions from other sources, see [0082], calibration to determine correction, see implementation 1 and Figs. 9-11), wherein the determining at least one correction relationship comprises determining correction relationships for each of a plurality of different nominal stacks and/or illumination conditions of the measurement radiation (different illumination modes, see [0097]), comprising obtaining calibration measurement data comprising calibration target data and corresponding calibration surrounding observable parameter data (calibration measurement, see [0097]).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the clamed invention to provide the calibration for determining a correction as taught by Smilde in the correction as taught by Van De Kerkhof in order to optimize the correction for different pattern profiles caused by pattern dependent stray radiation.
For claim 22, Van De Kerkhof teaches the first measurement data comprises target measurement data relating to the one or more targets and corresponding surrounding observable parameter data relating to surrounding structure that is in the vicinity of the one or more targets (the radiation is focused on the target, there will additionally be diffraction from the surrounding pattern, see [0053]).
For claim 29, Van De Kerkhof fails to teach the at least one metrology apparatus comprises an alignment apparatus operable to perform pre-exposure metrology for performing positional metrology for positioning of one or both of the patterning device support and the substrate table.
Smilde teaches at least one metrology apparatus comprises an alignment apparatus operable to perform pre-exposure metrology for performing positional metrology for positioning of one or both of the patterning device support and the substrate table (AS, see Fig. 1, [0051] and [0054]).
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 pre-alignment metrology as taught by Smilde in the metrology correction as taught by Van De Kerkhof because pre-alignment allows for mapping the substrate to the apparatus while another substrate is being exposed, increasing throughput.
Response to Arguments
Applicant's arguments filed March 16, 2026 have been fully considered but they are not persuasive.
The Applicant argues on pages 10-12 of the Remarks, regarding the rejection of claim 23 under 35 USC 103 and the subject matter now incorporated into claims 16 and 27, that Ghinovker fail to teach the claimed non-visible targets because the dummy structures are not designed to measure a surrounding signal contribution. The Examiner respectfully disagrees. Ghinovker teaches in [0058]-[0060] training a metrology tool to remove surrounding device structure data by identifying the boundary regions using sub resolution dummy structures surrounding known metrology targets. The dummy structures are sub resolution targets because they are used to identify a known target by reducing cross talk and are not resolvable by nature. Accordingly the “gray” are surrounding contribution that can be identified and removed.
Additionally, Applicant’s arguments with respect to claims 16 and 27 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. Chen is relied upon to teach the salient features of the claims.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Fan et al. [US 2018/0238737] teaches in [0078] and Fig. 6 a dummy structure may comprise a sub-multiple pitch compared to the main pitch.
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/Steven H Whitesell/ Primary Examiner, Art Unit 1759
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