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
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 15-16, 18-20, 22 and 26 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Ohashi (US 20120286160 A1).
Regarding claim 15, Ohashi teaches a non-transitory computer readable medium (memory 124) comprising instructions (software, [0110]) that, when executed by one or more processors (controlling and operating device 121) cause the one or more processors to:
Obtain a plurality of sets of images, wherein each given set of images of the plurality of sets of images is informative of a given target of a semiconductor specimen (acquiring images at 25 measurement points, each having different focal position, fig. 11 S1102-S1107),
Wherein each given set of images has been acquired by an electron beam examination system transmitting an electron beam towards the semiconductor specimen through a device (image shift deflector 104),
Wherein, for each given set of images, the electron beam has been controlled according to a control enabling acquisition of said given set of images with the electron beam impinging the device at a position which differs from a position at which the electron beam impinges the device in an acquisition of each of the other sets of images (changing image shift amount, s1102 fig. 11),
Wherein, for each given set of images, each given image of the given set of images has been acquired by the electron beam examination tool with a different focal point than for acquisition of one or more other images of the given set of images (obtaining images with different focus positions, s1103 fig. 11),
Determine displacement data informative of a displacement of the given target in each given set of images, thereby obtaining a set of a plurality of displacement data (obtaining mark shift from plurality of images, s1104, fig. 11), and
Use the set of a plurality of displacement data and data informative of said control to determine:
A first model informative of electron beam deflection, generated based on an initial estimate of a control (parameters including alignment control value shown in fig. 14) enabling the electron beam to impinge the device at a required position (determining proportionality coefficients, s1104, fig. 11), and
A second estimate of control enabling the electron beam to impinge the device at the required position (updating parameters including alignment control value, s1113 fig. 11), and
Use the second estimate (estimated parameters including second alignment control value) to generate a second model (updated proportionality coefficients in s1104 in repeated process) usable to calibrate the device such that the electron beam transmitted through the device passes through the required position (updated control values used to repeat measurement in order to properly center beam in iterative process, fig. 11).
Regarding claim 16, Ohashi teaches that the second estimate of the control is more accurate than the first estimate of the control (updating control values, [0075], for more accurate alignment).
Regarding claim 18, Ohashi teaches a system comprising one or more processing circuitries (controlling and operating device 121) configured to:
Obtain a plurality of sets of images, wherein each given set of images of the plurality of sets of images is informative of a given target of a semiconductor specimen (acquiring images at 25 measurement points, each having different focal position, fig. 11 S1102-S1107),
Wherein each given set of images has been acquired by an electron beam examination system transmitting an electron beam towards the semiconductor specimen through a device (image shift deflector 104),
Wherein, for each given set of images, the electron beam has been controlled according to a control enabling acquisition of said given set of images with the electron beam impinging the device at a position which differs from a position at which the electron beam impinges the device in an acquisition of each of the other sets of images (changing image shift amount, s1102 fig. 11),
Wherein, for each given set of images, each given image of the given set of images has been acquired by the electron beam examination tool with a different focal point than for acquisition of one or more other images of the given set of images (obtaining images with different focus positions, s1103 fig. 11),
Determine displacement data informative of a displacement of the given target in each given set of images, thereby obtaining a set of a plurality of displacement data (obtaining mark shift from plurality of images, s1104, fig. 11), and
Use the set of a plurality of displacement data and data informative of said control to determine:
A first model informative of electron beam deflection, generated based on an initial estimate of a control (parameters including alignment control value shown in fig. 14) enabling the electron beam to impinge the device at a required position (determining proportionality coefficients, s1104, fig. 11), and
A second estimate of control enabling the electron beam to impinge the device at the required position (updating parameters including alignment control value, s1113 fig. 11), and
Use the second estimate (estimated parameters including second alignment control value) to generate a second model (updated proportionality coefficients in s1104 in repeated process) usable to calibrate the device such that the electron beam transmitted through the device passes through the required position (updated control values used to repeat measurement in order to properly center beam in iterative process, fig. 11).
Regarding claim 19, Ohashi teaches that the second estimate of the control is more accurate than the first estimate of the control (updating control values, [0075]).
Regarding claim 22, Ohashi teaches testing sensitivity of the first model (fitting the measurement results and determining if fitting coefficients are within limits, fig. 6 s607-s609).
Regarding claim 26, Ohashi teaches that said determination of displacement data comprises determining data informative of first displacements of the given target in said each given set along a first axis, independently from determining data informative of second displacements of the given target in said each given set of images along a second axis ([0051]).
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, 6-8 and 10-14 are rejected under 35 U.S.C. 103 as being unpatentable over Pearl (US 7,335,893 B2) in view of Ohashi.
Regarding claim 1, Pearl teaches a system comprising one or more processing circuitries (parameter adjustment unit 31) configured to:
Obtain a set of images (generating images, col. 3 line 17) of at least one element of a specimen (sample 105a),
Wherein the set of images has been acquired by an electron beam examination tool (electron microscope 100) operative to transmit an electron beam towards the r specimen through at least a stigmator of the electron beam examination tool, wherein the stigmator comprises:
Deflection elements (stigmators 902 and 903),
At least one electrical source (stigmator control and current supply unit 28) usable to control the deflection elements, and
A splitter configured to define a current distribution of a current generated by the electrical source between the deflection elements (implicit part of stigmator control unit, as it must define a current distribution to supply current to each coil);
Wherein each given image of the set of images has been acquired by the electron beam examination tool with a value of a given electrical parameter of the electrical source which differs from a value of the given electrical parameter used to acquire one or more images of the set (acquiring images while adjusting alignment, col. 12 lines 14-25), determine data informative of a displacement of the at least one element in the set of images (image shift, col. 12 lines 26-37), and
Use the data and model informative of the device to determine a current distribution defined by the splitter (adjusting beam deflection amount, col. 12 lines 38-51), wherein the calibrated current distribution is configured such that one or more variations of the current generated by the at least one electrical source, operative to modify a shape of the electron beam, do not deflect the electron beam (i.e. by the known function of a stigmator there is at least some current variation from the calibrated distribution which will modify the shape of the beam without deflecting it; the claim does not require these variations to be part of the imaging and calibration process used to find the calibrated distribution).
Pearl does not state that the sample is a semiconductor.
Ohashi teaches examining a semiconductor wafer in an electron microscope ([0003]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the invention to make the sample of Pearl a semiconductor as taught by Ohashi, as inspection of semiconductor wafers is an extremely common use of SEM imaging to which the system of Pearl can be applied with no unexpected result.
Regarding claim 2, Pearl teaches the calibrated current distribution is such that one or more other variations of the current generated by the at least one electrical source, operative to modify a shape of the electron beam, deflect the electron beam with a deflection below a threshold (i.e. by the known function of a stigmator there is at least some current variation from the calibrated distribution which will modify the shape of the beam with some limited deflection).
Regarding claim 6, Pearl teaches that each given image of the set of images has been acquired by the electron beam examination tool with a current generated by the electron source which differs from a current generated by the electrical source to acquire one or more other images of the set (adjusting deflection, col. 12 lines 36-40).
Regarding claim 7, Pearl teaches that the model is informative of a relationship between one or more electrical parameters used to control the deflection elements and data informative of a displacement of the element of the set of images (equation relating current of stigmator to image shift, col. 12 lines 37-51).
Regarding claim 8, Pearl teaches that the system is configured to use the calibrated current distribution to control the current distribution defined by the stigmator.
Regarding claim 10, Pearl teaches that determining data informative of first displacements of the at least one element in the set of images along a first axis is performed independently from determining data informative of second displacements of the at least one element in the set of images along a second axis (separate calibration for each axis, col. 12 lines 28-31).
Regarding claim 11, Pearl teaches that determining data informative of a displacement of at least one element in the set of images includes:
Determining a first coefficient (Cx, sens) of a first function linking displacement of the at least one element in the set of images along a first axis (Dx) to data informative of a control of the deflection elements used to acquire the set of images (Ix, col 12 line 44); and
Determining a second coefficient (Cy, sens) of a second function linking displacement of the at least one element in the set of images along a second axis (Dy) to data informative of a control of the deflection elements used to acquire the set of images (Iy, col 12 line 44).
Regarding claim 12, Pearl teaches that the at least one electrical source comprises a first electrical source and a second electrical source, the deflection elements comprise a first pair of deflection elements (x-stigmators 902) associated with the first electrical source and a second pair of deflection elements (y-stigmators 903) associated with the second electrical source, wherein the system is configured to:
Determine a first calibrated current distribution between the first deflection elements, wherein the calibrated current distribution is configured such that one or more variations of the current generated by the first electrical source, operative to modify a shape of the electron beam, do not deflect the electron beam (i.e. by the known function of a stigmator there is at least some current variation from the calibrated distribution which will modify the shape of the beam without deflecting it; the claim does not require these variations to be part of the imaging and calibration process used to find the calibrated distribution).
Determine a second calibrated current distribution between the second deflection elements, wherein the calibrated current distribution is configured such that one or more variations of the current generated by the second electrical source, operative to modify a shape of the electron beam, do not deflect the electron beam (by reasoning used above for the first deflector).
Regarding claim 13, Pearl teaches that the sensitivity of the model has been tested (old sensitivity calibration, col. 12 lines 14-20).
Regarding claim 14, Pearl teaches a non-transitory computer readable medium comprising instructions (software, col. 4 lines 42-50) implicitly stored on a medium) that, when executed by one or more processors (parameter adjustment unit 31) cause the one or more processors to:
Obtain a set of images (generating images, col. 3 line 17) of at least one element of a specimen (sample 105a),
Wherein the set of images has been acquired by an electron beam examination tool (electron microscope 100) operative to transmit an electron beam towards the semiconductor specimen through a stigmator of the electron beam examination tool, wherein the stigmator comprises deflection elements (stigmators 902 and 903) and at least one electrical source (stigmator control and current supply unit 28) usable to control the deflection elements,
Deflection elements (stigmators 902 and 903),
At least one electrical source (stigmator control and current supply unit 28) usable to control the deflection elements, and
A splitter configured to define a current distribution of a current generated by the electrical source between the deflection elements (implicit part of stigmator control unit, as it must define a current distribution to supply current to each coil);
Wherein each given image of the set of images has been acquired by the electron beam examination tool with a value of a given electrical parameter of the electrical source which differs from a value of the given electrical parameter used to acquire one or more images of the set (acquiring images while adjusting alignment, col. 12 lines 14-25),
Determine data informative of a displacement of the at least one element in the set of images (image shift, col. 12 lines 26-37), and
Use the data and model informative of the device to determine a current distribution defined by the splitter (adjusting beam deflection amount, col. 12 lines 38-51), wherein the calibrated current distribution is configured such that one or more variations of the current generated by the at least one electrical source, operative to modify a shape of the electron beam, do not deflect the electron beam (i.e. by the known function of a stigmator there is at least some current variation from the calibrated distribution which will modify the shape of the beam without deflecting it; the claim does not require these variations to be part of the imaging and calibration process used to find the calibrated distribution).
Pearl does not state that the sample is a semiconductor.
Ohashi teaches examining a semiconductor wafer in an electron microscope ([0003]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the invention to make the sample of Pearl a semiconductor as taught by Ohashi, as inspection of semiconductor wafers is an extremely common use of SEM imaging to which the system of Pearl can be applied with no unexpected result.
Claims 9, 23 and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Pearl in view of Ohashi and in further view of Adiga (US 20230177715 A1).
Regarding claims 9 and 23, Pearl and Ohashi teach all the limitations of claim 1 and claim 14 as described above. Pearl and Ohashi do not teach that the determination of data informative of displacement of the given target in the given set of images comprises, for each given axis of one or more axes, using one-dimensional image registration along this given axis to determine data informative of a displacement of the given target in the given set of images along this given axis.
Adiga teaches a method of determining location of a target in an images, including for each of two axes, using one-dimensional image registration along the given axis (locating a fiducial, [0035-0036]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date to modify the system of Pearl to have the image registration method of Adiga, as a matter of selecting a known effective image displacement determination algorithm used in the art to independently measure a displacement in two directions with no unexpected result.
Regarding claim 25, Pearl and Ohashi do not teach that determination of data informative of a displacement of the at least one element in the set of images includes using a projection of pixel intensity along a first axis of one or more images in the set of images to determine data informative of first displacements of the at least one element in the set of images along the first axis, and using a projection of pixel intensity along a second axis of the one or more images of the set of images to determine data informative of second displacements of the at least one element in the set of images along the second axis.
Adiga teaches a method of locating an element in an image including using a projection of pixel intensity along each axis to determine the location of the image along that axis ([0035-0036]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the invention to modify the system of Pearl to have the image registration method of Adiga, as a matter of selecting a known image displacement determination algorithm used in the art with no unexpected result.
Claims 17 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Ohashi in view of Adiga.
Regarding claims 17 and 21, Ohashi does not teach that the determination of data informative of displacement of the given target in the given set of images comprises, for each given axis of one or more axes, using one-dimensional image registration along this given axis to determine data informative of a displacement of the given target in the given set of images along this given axis.
Adiga teaches a method of determining location of a target in an images, including for each of two axes, using one-dimensional image registration along the given axis (locating a fiducial, [0035-0036]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date to modify the system of Ohashi to have the image registration method of Adiga, as a matter of selecting a known image displacement determination algorithm used in the art with no unexpected result.
Claim 24 is rejected under 35 U.S.C. 103 as being unpatentable over Pearl in view of Ohashi and in further view of Kawamoto (US 11,056,310 B2).
Regarding claim 24, Pearl teaches that the model has been generated using one or more targets. Pearl does not teach that the targets comprise one or more horizontal lines or one or more vertical lines.
Kawamoto teaches an electron beam calibration system having an imaging target comprising horizontal and vertical lines (fig. 2B, col. 5 lines 20-41).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the claims to include the imaging target of Kawamoto as a substitute for or as part of the imaging target of Ohashi, in order to perform accurate calibration of the system using an equivalent type of target known in the art with no unexpected result.
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Pearl in view of Ohashi and in further view of Virdi (US 20230253177 A1).
Regarding claim 27, Pearl and Ohashi do not teach determining evolution of a width of the element in the set of images and determining whether it matches a focal point variation used to generate the set of images.
Virdi teaches a charged particle imaging system which can determine the evolution of the width of an element in a set of images and determine whether it matches a focal point variation used to generate the set of images (calibrating images, determining measurement error for multiple focusing strengths, [0050-0051]; errors are based on dimension measurements, [0054]; fitting a line to determine matching, [0052]).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the invention to modify the system of Pearl to evaluate the evolution of the width of the imaging element as a function of focal point variation as taught by Virdi, in order to ensure proper calibration of the focusing strength of the instrument with no unexpected result.
Response to Arguments
Applicant's arguments filed 16 June 2026 have been fully considered but they are not persuasive.
Regarding the rejection of claim 18 as anticipated by Ohashi, Applicant argues that Ohashi does not teach a first model informative of electron beam deflection, generated based on an initial estimate of a control enabling the electron beam to impinge the device at a required position”. It is true that Ohashi’ proportionality coefficients are calculated from mark shift vs focus change and are used to obtain a landing angle. However the proportionality coefficients (which examiner interprets as a model informative of electron beam deflection, i.e. a landing angle which is determined by some deflection of the beam to form the angle) are generated using an estimate of other alignment parameters including a alignment value (steps s1101 and s1102 of fig. 11 of Ohashi). This parameter is interpreted as “a control enabling the electron beam to impinge the device at a required position”, as it is a control parameter that determines the position of the electron beam, and which is updated based on the results of the model (coefficients of the mark shift vs. focus change graph).
Regarding the argument that Ohashi does not teach “a second estimate of a control enabling the electron beam to impinge the device at the required position”, the method of Ohashi updates an alignment parameter in order to ensure that the beam is properly aligned (s1101) so that the beam impinges the sample at a desired position. Ohashi then uses this updated parameter to generate a second model, by regenerating the proportionality coefficients which determine the electron beam deflection.
Regarding the rejection of claim 1 in view of Pearl and Ohashi, Applicant argues that “Pearl does not disclose or suggest that a current generated by an electrical source is supplied to a splitter configured to define a distribution of that current between multiple deflection elements”. However the stigmator control means of Pearl decides on a distribution of current between the elements of the stigmator, and so can be considered a current splitter as defined the current claims.
Regarding the statement that “the calibrated current distribution is configured such that one or more variations of the current generated by the at least one electrical source, operative to modify a shape of the electron beam, do not deflect the electron beam.” However this is simply a statement that the current distribution can be varied in order to adjust the shape of the beam, which is a simple function of a stigmator as understood in the prior art. While Pearl teaches the process of calibrating the position of the electron beam, rather than the shape, the current claims do not require calibrating the shape of the beam independent of position.
Conclusion
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DAVID E SMITH whose telephone number is (571)270-7096. The examiner can normally be reached M to F 8:30 AM-5:00 PM.
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/DAVID E SMITH/Examiner, Art Unit 2881
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