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 § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-4, 6-9, 13-17, 19 and 20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Zhang (US 2018/0100814 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).
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).
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).
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).
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 10-12 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang, as applied to claim 1 above, in view of Yoshida (US 2005/0062963 A1).
With respect to claim 10, Zhang further discloses that the patterned layer 404 has a ring (rotational symmetry complementing the shape of the illumination aperture for substantially the same reasons as that of the phase contrast region: pars.0044 and 0047).
However, Zhang does not specifically disclose that the ring has 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, Zhang further discloses that the patterned layer 404 has a ring (rotational symmetry complementing the shape of the illumination aperture for substantially the same reasons as that of the phase contrast region: pars.0044 and 0047).
However, Zhang does not specifically disclose that the ring has 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, Zhang further discloses that the patterned layer 404 has a plurality of concentric rings (rotational symmetry complementing the shape of the illumination aperture for substantially the same reasons as that of the phase contrast region: pars.0044 and 0047; and Fig.4B, rotational symmetry results in three concentric attenuation rings and two concentric transmissive rings with a central transmissive circle, where the diameter of the illumination aperture is W from Fig.4A).
However, Zhang 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, 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
The present amendment to claim 12 overcomes the outstanding 35 USC 112(b) rejection of record.
Applicant's arguments with respect to the anticipation of claims 1 and 13, as amended, by Zhang have been fully considered but they are not persuasive. Applicant argues that Zhang does not disclose specific transmittances, and thus cannot anticipate the claims as amended (Remarks, p.6 of 8). The Examiner respectfully disagrees.
First, the claim only requires that at least one region have 100% transmission, and that at least one region has less than 100% but more than 0% transmission. That’s essentially the entire range of possible transmittances.
Second, Zhang illustrates in Fig.4B and discloses in par.0045 that “the transmission of the filter…may also be controlled by putting half-tone metallic or other partially transmissive patterns on the flat side of the glass, made by material compatible with DUV light, such as chrome, aluminum or nickel.” “Half-tone” is understood to be approximately 50% transmittance, and the term “partially transmissive” is exactly the claimed range of less than 100% but more than 0%. Therefore, Zhang specifically discloses having a region of 100% transmittance (areas with no layer 404, Fig.4B), and areas having less than 100% but more than 0% transmittance (areas with layer 404, Fig.4B).
For at least these reasons, Zhang anticipates claims 1 and 13 as amended, and therefore the rejections are being maintained.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to THOMAS R ARTMAN whose telephone number is (571)272-2485. The examiner can normally be reached Monday-Thursday 10am-6:30pm.
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THOMAS R. ARTMAN
Primary Examiner
Art Unit 2884
/THOMAS R ARTMAN/Primary Examiner, Art Unit 2884
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