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 18-20, 22-23 and 26 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Ohashi (US 20120286160 A1).
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 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 alignment control value, s1113 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 20, Ohashi teaches using the second estimate to generate a second model informative of electron beam deflection (updating control value of focus and astigmatism, s1114, fig. 11).
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 23, Ohashi teaches a system comprising one or more processing circuitries (controlling and operating device 121) configured to:
Obtain a set of images (plural sheets of images, [0050]), of at least one element of a semiconductor specimen (semiconductor, [0003]; measuring a measurement mark on sample 107, [0050]),
Wherein the set of images has been acquired by an electron beam examination tool (electron microscope, fig. 1) operative to transmit an electron beam towards the semiconductor specimen through a device of the electron beam examination tool (objective lens 106),
Wherein each given image of the set of images has been acquired by the electron beam examination tool with a different focal point of the electron beam than for acquisition of one or more other images of the set of images (acquire images of mark with different focus positions, s203, [0050]),
Determine data informative of a displacement of the at least one element in the set of images (obtain mark shift, s204), said displacement comprising, 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 at least one element in the set of images along this given axis (shift in each direction, [0051]), and
Use the data and a model informative of electron beam deflection to determine data usable to move the electron beam to a required position of the electron beam in the device (determining proportionality coefficients and landing angle to determine corrected optical condition, s205-s207, [0052-0053]).
Regarding claim 26, Ohashi teaches that said determination comprises determining data informative of first displacements of the at least one element in the set of images along a first axis, independently from determining data informative of second displacements of the at least one element in the 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 1-8 and 10-17 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 part of a device of the electron beam examination tool, wherein the device 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,
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 data enabling control of the device for which deflection of the electron beam by the deflection elements meets a calibration criterion (adjusting beam deflection amount, col. 12 lines 38-51).
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 that the calibration criterion is such that a predefined variation of the given electrical parameter of the electrical source does not deflect the electron beam (alignment with respect to optical axis, col. 3 lines 54-57; aligning with the axis implies that the beam is not deflected).
Regarding claim 3, Pearl teaches that the calibration criterion is such that a predefined variation of the given electrical parameter of the electrical source enables modifying a shape of the electron beam without deflecting the electron beam (i.e. the current to the stigmator allows the stigmator to function to modify the beam shape (implicit function of a stigmator) while the beam is not deflected, i.e. aligned to the optical axis).
Regarding claim 4, Pearl teaches that data enabling control of the device comprises data informative of a current distribution of a current generated by the electrical source between the deflection elements (current in x- and y- stigmators, col. 12 lines 37-51).
Regarding claim 5, Pearl teaches that the device is a stigmator of the electron beam examination tool.
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 data enabling control of the device to send a command to the electron beam examination tool to enable a deflection of the electron beam by the deflection elements which meets the calibration criterion (the criterion being alignment of the beam with the axis, col. 3 lines 54-57).
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 device includes a first pair of deflection elements (x-stigmators 902) associated with a first electrical source and a second pair of deflection elements (y-stigmators 903) associated with a second electrical source, wherein the system is configured to:
Determine first data informative of a current distribution of a current generated by the first electrical source, between the first pair of deflection elements, for which deflection of the electron beam by the first pair of deflection elements meets the calibration criterion, and
Determine second data informative of a current distribution of a current generated by the second electrical source, between the second pair of deflection elements, for which deflection of the electron beam by the second pair of deflection elements meets the calibration criterion (separate alignment using current data for x and y axes, col. 12 lines 49-52).
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 processing circuitries (parameter adjustment unit 31) cause the one or more processing circuitries to perform:
Obtaining 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 at least part of a device of the electron beam examination tool, wherein the device 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,
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
Using the data and model informative of the device to determine data enabling control of the device for which deflection of the electron beam by the deflection elements meets a calibration criterion (adjusting beam deflection amount, col. 12 lines 38-51).
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 15, Pearl teaches a non-transitory computer readable medium comprising instructions (software, implicitly on a medium, col. 4 lines 42-50) that, when executed by one or more processing circuitries (parameter adjustment unit 31) cause the one or more processing circuitries to perform:
Obtaining a set of images (generating images, col. 3 line 17), wherein each given set of images of the plurality of sets of images is informative of a given target of a system (sample 105a),
Wherein each given 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 at least part of a device of the electron beam examination tool, wherein the device comprises deflection elements (stigmators 902 and 903),
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 a distribution of an electrical parameter used to control the deflection elements which differs from a distribution of the electrical parameter used to control the deflection elements in an acquisition of each of the other sets of images (acquiring images while adjusting alignment, col. 12 lines 14-25),
Determining 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 (image shift, col. 12 lines 26-37), and
Using the set of a plurality of displacement data and data informative of said control to generate a model usable to calibrate the device (adjusting beam deflection amount, col. 12 lines 38-51).
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 16, Pearl teaches that for at least one given set of images, each given image of the given set of images has been acquired by the electron beam examination tool with a current generated by the electrical source for controlling the deflection elements which differs from a current generated by the electrical source for controlling the deflection elements in an acquisition of one or more other images in the given set of images (adjusting deflection caused by current applied to stigmator, col. 12 lines 36-40).
Regarding claim 17, Pearl teaches instructions that, when executed by the one or more processing circuitries, cause the one or more processing circuitries to:
Determine a first model associated with an initial estimate of a calibrated current distribution between the deflection elements (formerly calibrated sensitivity factors, col. 13 lines 2-3, for current distribution between deflection elements, col. 12 lines 60-65); and a second estimate of the calibrated current distribution, and use the second estimate of the calibrated current distribution to generate the model (re-generating the model using new sensitivity factors that relate the currents, col. 12 line 65-col. 13 line 6).
Claim 9 is 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 claim 9, Pearl and Ohashi teach all the limitations of claim 1 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.
Claims 21 and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Ohashi in view of Adiga.
Regarding claim 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.
Regarding claim 25, Ohashi does 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 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 Ohashi in view of Kawamoto (US 11,056,310 B2).
Regarding claim 24, Ohashi teaches that the model has been generated using one or more targets. Ohashi 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 Ohashi in view of Virdi (US 20230253177 A1).
Regarding claim 27, Ohashi does 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 Ohashi 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.
Conclusion
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