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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 9/1/2026 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 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, 6-9, 13-17, 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang (US 2018/0100814 A1) in view of Kim (US 2021/0396510 A1).
Regarding claim 1, Zhang discloses an inspection system (Fig.3), including:
a) a light source 302 that generates a beam of light;
b) illumination optics 304, 306, 308 configured to direct the beam of light onto an EUV reticle 310;
c) a pupil filter 307 positioned to an imaging pupil of the inspection system, where the pupil filter 307 is configured to provide spatially-varying intensity transmission (Fig.4B), where the spatially-varying intensity transmission includes at least a first section with 100% transmission (areas with no layer 404) and a second section with a transmission less than 100% and greater than 0% (par.0045), where the pupil filter 307 is a slab of glass with a patterned layer 404 disposed on a surface of the slab (pars.0043-0045);
d) a detector 314 that receives an output beam from the pupil filter 307 and is configured to generate an image for the output beam; and
e) collection optics 308, 313 for directing the output beam that is reflected and scattered from the EUV reticle 310 in response to the beam of light, where the output beam is directed through the pupil filter 307 toward the detector 314 (Fig.3).
Further regarding claim 1, Zhang does not specifically disclose that the spatially-varying intensity transmission includes at least a first ring with 100% transmission, a second ring different from the first ring with a transmission less than 100% and greater than 0%, and a third ring different from the first ring and the second ring with a transmission of 0%. Zhang only generally teaches that the pupil filter may have rotational symmetry complementing the shape of the illumination aperture for substantially the same reasons as that of the phase contrast region (pars.0044-0045 and 0047).
Kim teaches the practice of providing 3 such rings (Fig.4A) for a pupil filter 124 of a defect inspection system (Figs.1-3), where a first ring has 100% transmission (through substrate 124-4), a second ring different from the first ring with a transmission less than 100% and greater than 0% (through film 124-3), and a third ring different from the first and second rings having a transmission of 0% (reflected off of film 124-1). In this manner, defects in the target (semiconductor wafer) are amplified through manipulating the phase shifts for optimal image contrast (pars.0054-0055, 0066 and 0069).
It would have been obvious to one of ordinary skill in the art at the time of the invention for Zhang to have 3 such rings as claimed in order to optimize the defect contrast in the inspection image, as taught by Kim.
With respect to claim 2, Zhang further discloses that the patterned layer 404 includes at least two different shapes and/or sizes across the surface (par.0045).
With respect to claim 3, Zhang further discloses that the patterned layer 404 has a varying density across the surface (positive and negative space, Fig.4B; also see par.0045).
With respect to claim 4, it is further evident in Zhang that the patterned layer 404 is rotationally symmetric across the surface (mirroring the shape of the illumination aperture for substantially the same reasons as that of the phase contrast region: pars.0044 and 0047).
With respect to claim 6, Zhang further discloses that the patterned layer 404 is chrome or another metal (or any material compatible with DUV light: par.0045).
With respect to claim 7, Zhang further discloses that the pupil filter 307 is further configured to provide phase contrast in the output beam (Figs.4A and 4B; pars.0043-0045).
With respect to claim 8, Zhang further discloses that the slab of glass has an etched portion W having a depth h corresponding to an amount of phase change that is introduced into a portion of the output beam that is transmitted through the pupil filter 307 (par.0043). This is also taught by Kim (Fig.4A).
With respect to claim 9, Zhang further discloses that the patterned layer 404 is disposed on a side of the slab of glass opposite from the etched portion W (Fig.4B).
Regarding claim 13, Zhang discloses a method of inspecting an EUV reticle (Fig.9), including:
a) using an inspection system to obtain a test image from an output beam that is reflected and scattered from a test portion of the EUV test reticle 310, where the inspection system is configured to provide a spatially-varying intensity transmission using a pupil filter 307 that is a slab of glass with a patterned layer 404 disposed on a surface of the slab of glass (steps 902-906; also see Figs.3 and 4B);
b) obtaining a reference image for a reference reticle portion that is designed to be identical to the test reticle portion (stpe.908);
c) comparing, using a processor, the test image and the reference image (step 910); and
d) determining, using the processor, whether the test reticle portion has a candidate defect based on the comparing (step 912).
Further regarding claim 13, Zhang does not specifically disclose that the spatially-varying intensity transmission includes at least a first ring with 100% transmission, a second ring different from the first ring with a transmission less than 100% and greater than 0%, and a third ring different from the first ring and the second ring with a transmission of 0%. Zhang only generally teaches that the pupil filter may have rotational symmetry complementing the shape of the illumination aperture for substantially the same reasons as that of the phase contrast region (pars.0044-0045 and 0047).
Kim teaches the practice of providing 3 such rings (Fig.4A) for a pupil filter 124 of a defect inspection system (Figs.1-3), where a first ring has 100% transmission (through substrate 124-4), a second ring different from the first ring with a transmission less than 100% and greater than 0% (through film 124-3), and a third ring different from the first and second rings having a transmission of 0% (reflected off of film 124-1). In this manner, defects in the target (semiconductor wafer) are amplified through manipulating the phase shifts for optimal image contrast (pars.0054-0055, 0066 and 0069).
It would have been obvious to one of ordinary skill in the art at the time of the invention for Zhang to have 3 such rings as claimed in order to optimize the defect contrast in the inspection image, as taught by Kim.
With respect to claim 14, Zhang further discloses (Fig.9);
e) repeating the using the inspection system, the obtaining the reference image, the comparing, and the determining steps for each of a plurality of test reticle portions of the reticle (arrow from step 912 to 902); and
f) generating a defect report based on the candidate defects that have been determined to be present (par.0065).
With respect to claim 15, Zhang further discloses that the patterned layer 404 includes at least two different shapes and/or sizes across the surface (par.0045).
With respect to claim 16, Zhang further discloses that the patterned layer 404 has a varying density across the surface (positive and negative space, Fig.4B; also see par.0045).
With respect to claim 17, it is further evident in Zhang that the patterned layer 404 is rotationally symmetric across the surface (mirroring the shape of the illumination aperture for substantially the same reasons as that of the phase contrast region: pars.0044 and 0047).
With respect to claim 19, Zhang further discloses that the pupil filter 307 is further configured to provide phase contrast in the output beam (Figs.4A and 4B; pars.0043-0045).
With respect to claim 20, Zhang further discloses that the slab of glass has an etched portion W having a depth h corresponding to an amount of phase change that is introduced into a portion of the output beam that is transmitted through the pupil filter 307 (par.0043).
Claims 10-12 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang and Kim, as applied to claim 1 above, in view of Yoshida (US 2005/0062963 A1).
With respect to claim 10, neither Zhang nor Kim specifically disclose that the rings each have a width in a range from 100nm to 5000nm.
Yoshida teaches a pupil filter 41 for an optical inspection device for inspecting patterns on a wafer 1, where the pupil filter 41 has a ring shape (Figs.49(a)&(b)). The desired shape and transmissivities of the regions of the pupil filter 41 are selected based on the test light wavelength and the determined optimal conditions for the defects of the sample under test (pars.0084 and 0130).
It would have been obvious to one of ordinary skill in the art at the time of the invention for Zhang to have the patterned layer 404 have a ring shape with a width ranging from 100nm to 5000nm in order to establish the optimal parameters for detecting the defects of the sample under test with a given wavelength of light, as suggested by Yoshida, with a reasonable expectation of success and without undue experimentation. Further, when the general conditions of the claim have been met, finding a workable or optimal set of values for an art-recognized result-effective variable only requires routine experimentation within the art, absent and unexpected result or other critical nature, and particularly given such a large range as that claimed.
With respect to claim 11, neither Zhang nor Kim disclose that the rings have a thickness in a range from 10nm to 250nm.
Yoshida teaches a pupil filter 41 for an optical inspection device for inspecting patterns on a wafer 1, where the pupil filter 41 has a ring shape (Figs.49(a)&(b)). The desired shape and transmissivities of the regions of the pupil filter 41 are selected based on the test light wavelength and the determined optimal conditions for the defects of the sample under test (pars.0084 and 0130).
It would have been obvious to one of ordinary skill in the art at the time of the invention for Zhang to have the patterned layer 404 have a ring shape with a thickness ranging from 10nm to 250nm in order to establish the optimal parameters for detecting the defects of the sample under test with a given wavelength of light, as suggested by Yoshida, with a reasonable expectation of success and without undue experimentation. Further, when the general conditions of the claim have been met, finding a workable or optimal set of values for an art-recognized result-effective variable only requires routine experimentation within the art, absent and unexpected result or other critical nature, and particularly given such a large range as that claimed.
With respect to claim 12, Kim further discloses that the rings are concentric (Fig.4A).
However, Kim does not specifically disclose that the spacing between adjacent rings ranges from 100nm to 5000nm.
Yoshida teaches a pupil filter 41 for an optical inspection device for inspecting patterns on a wafer 1, where the pupil filter 41 has a ring shape (Figs.49(a)&(b)). The desired shape and transmissivities of the regions of the pupil filter 41 are selected based on the test light wavelength and the determined optimal conditions for the defects of the sample under test (pars.0084 and 0130).
It would have been obvious to one of ordinary skill in the art at the time of the invention for Zhang to space adjacent rings by 100nm to 5000nm in order to establish the optimal parameters for detecting the defects of the sample under test with a given wavelength of light, as suggested by Yoshida, with a reasonable expectation of success and without undue experimentation. Further, when the general conditions of the claim have been met, finding a workable or optimal set of values for an art-recognized result-effective variable only requires routine experimentation within the art, absent and unexpected result or other critical nature, and particularly given such a large range as that claimed.
Claims 5 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang and Kim, as applied to claims 1 and 13, respectively, in view of Kolchin (US 2014/0354983 A1).
With respect to claims 5 and 18, Zhang does not specifically disclose that the patterned layer has a rotationally asymmetric pattern across the surface.
Kolchin teaches the practice of determining the optimal shape at the illumination pupil plane 105 and at the Fourier pupil plane 122 (the latter being the location of the pupil filter of Zhang) for optical inspection of defects on reticles or wafers (Fig.1). The optimal illumination side and collector side shapes for a given defect may be rotationally symmetric or asymmetric (Figs.1 and 7-10, also see pars.0047, 0051 and 0079).
It would have been obvious to one of ordinary skill in the art at the time of the invention for Zhang to have the patterned layer form a rotationally asymmetric shape across the surface in order to optimize the defect detection, as taught by Kolchin, with a reasonable expectation of success and without undue experimentation.
Response to Arguments
Applicant's arguments with respect to the anticipation of claims 1 and 13 by Zhang have been fully considered and are persuasive. The present amendments to the claims overcome the outstanding rejections of record.
However, a new grounds of rejection has been set forth in view of Kim, cited in the PTO-892 mailed 9/22/2025.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure (see attached PTO-892 unless otherwise stated):
US patent documents to Stokowski teach a detector structure/readout arrangement that has a similar effect to that of a pupil filter in a defect inspection system (Figs.4B and 5); and
Japanese patent document to Ozawa teaches an arrangement where the pupil filter is configured to match the geometry of the illumination in a defect inspection system (Fig.1); and
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THOMAS R. ARTMAN
Primary Examiner
Art Unit 2884
/THOMAS R ARTMAN/ Primary Examiner, Art Unit 2884
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