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 .
Drawings
The drawings are objected to as failing to comply with 37 CFR 1.84(p)(5) because they include the following reference character(s) not mentioned in the description: element 231 as shown in Fig. 9. Paragraph [00117] of the specification recites that Fig. 9 depicts the measured spectral signals illustrated by plotline 221 of Fig. 8 mapped to an inverse wavelength domain. It would appear that element 231 shown in Fig. 9 is actually element 221.
Corrected drawing sheets in compliance with 37 CFR 1.121(d), or amendment to the specification to add the reference character(s) in the description in compliance with 37 CFR 1.121(b) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Objections
Claims 1 and 19 are objected to because of the following informalities:
Line 21 of claim 1 recites “…indicative of a reflectivity the structure under…” when it should instead recite “…indicative of a reflectivity of the structure under…”.
Line 21 of claim 19 recites “…indicative of a reflectivity the structure under…” when it should instead recite “…indicative of a reflectivity of the structure under…”.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 11 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Lines 2-4 of Claim 11 recites the limitation "the SR subsystem" in “…an illumination Numerical Aperture (NA) of the SR subsystem is between 0.04 and 0.08, and wherein a collection NA of the SR subsystem is between 0.01 and 0.04”. There is insufficient antecedent basis for this limitation in the claim, nor is SR subsystem defined in the claims. It is unclear what is meant by SR subsystem. From the specification, paragraphs [0035-0038] recites a spectroscopic reflectometer, therefore, it would appear that the SR subsystem is describing a spectroscopic reflectometer. Paragraph [0014] of the specification further recites that the spectroscopic reflectometer includes low numerical aperture (NA) optics. Therefore, as best understood and therefore interpreted, SR subsystem is a spectroscopic reflectometer.
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 (i.e., changing from AIA to pre-AIA ) 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, 3-8, 10-16, and 18-19 are rejected under 35 U.S.C. 103 as being unpatentable over Madsen (WO 2016015734 A1, with portions cited below from an attached translation) in view of Dirks (US 2017/0017738 A1) and further in view of Bauer et al (“Very high aspect ratio through silicon via reflectometry”, June 2017, SPIE, Vol. 10329).
Regarding Claims 1, 12, and 19, Madsen teaches a metrology system and method comprising:
at least one illumination source (Fig. 1: light source 1) generating a first amount of broadband illumination light ([0054]: Light source is a broadband light source.);
an optical objective (Fig. 1: low numerical aperture (NA) objective 5) directing the first amount of broadband illumination light to a first measurement spot on a surface of a specimen (Fig. 1: sample 6) under measurement and collecting a first amount of collected light from the first measurement spot in response to the first amount of broadband illumination light (shown in Fig. 1 where objective 5 collects scattered light from sample 6 [0140]), wherein the optical objective directs the first amount of broadband illumination light to the first measurement spot at a nominal incidence angle that is normal to the surface of the specimen (shown in Fig. 1) and a numerical aperture that is less than 0.08 ([0050]: Low numerical aperture can have a value between 0.01 to 0.30.), wherein a structure (structures as shown in Figs. 3-5) under measurement is disposed within the first measurement spot (shown in Fig. 1);
a spectrometer (Fig. 1: detector 9; [0152]: A hyperspectral CCD imaging system is used as the detector 9.; [0032]) having a surface sensitive to incident light ([0082]: One or more light sources are synchronized with the image analyzer(s) at least in wavelength(s) and/or light intensity.), the spectrometer detecting the first amount of collected light (shown in Fig. 1) and generating measured spectral signals (multispectral data from [0035]) indicative of a reflectivity of the structure under measurement based on the first amount of collected light ([0140]: Light is scattered (e.g., diffuse reflection) off of sample 6 which is then detected by detector 9.); and
one or more computing systems ([0028]: Computer simulations would necessarily require some sort of computing system.), and a non-transitory, computer-readable medium storing instructions that, when executed by one or more processors, causes the one or more processors to:
simulate a first reflectivity (diffraction efficiency from [0163] includes reflectivity of the target structure being measured) of the structure under measurement using an electro-magnetic solver (RCWA (rigorous coupled wave analysis) from [0163-0164]; [0175]) based on first assumed values of one or more parameters of interest characterizing a shape ([0165]: Models are modeled with dimensional parameters (height, width, and angle).) of the structure under measurement ([0164-0165]: “RCWA is a much faster algorithm for modeling diffraction efficiency. It is based on calculating the diffraction of individual plates and then connecting each plate to each other through boundary conditions. The RCWA algorithm is the preferred algorithm for quickly and accurately simulating the diffraction efficiency from a structured surface. By using periodic boundary conditions, structures such as one-dimensional lattices and two-dimensional arrays can be calculated. The use of nonperiodic boundary conditions also allows you to calculate individual elements, such as individual grooves or lines.”);
estimate a first reflectivity (measured reflection coefficient from [0167]) of the structure under measurement based on a coherent sum of the simulated first reflectivity associated the structure under measurement ([0164-0167]: RCWA algorithm, which is a Maxwell equation solver, calculates the phase-sensitive amplitudes of electromagnetic waves which are a superposition of electric and magnetic waves. Therefore, RCWA necessarily includes coherent summation.); and
generate a first set of updated values (optimal set of dimensional parameters from [0106]) of the one or more parameters of interest based on a difference between the measured reflectivity and estimated first reflectivity of the structure ([0106-0107]: Determination of an optimal set of dimensional parameters is achieved based on electromagnetic calculations (estimated reflectivity) which is then compared with measured values from measuring scattering intensity (measured reflectivity).; Optimize parameter fitting (from [0111]) includes minimizing the difference between the estimated and measured reflectivity to obtain an optimize parameter.; shown in Fig. 8).
Madsen appears to be silent to the structure under measurement includes a plurality of substructures;
simulate a first reflectivity of each substructure of the structure under measurement using an electro-magnetic solver based on first assumed values of one or more parameters of interest characterizing a shape of the structure under measurement;
estimate a first reflectivity of the structure under measurement based on a coherent sum of the simulated first reflectivity associated with each substructure of the structure under measurement.
Dirks, related to the metrology of microscopic structures, does teach that the structure (Fig. 2: target structure 260) under measurement includes a plurality of substructures (Fig. 2: Trenches 264 and 266 are sub-structures of target structure 260 [0061].);
simulate a first reflectivity (Paragraphs [0075-0087] describe modelling/simulation of a target structure which includes a 1D or 2D array of substructures on a substrate.) of each substructure of the structure under measurement using an electro-magnetic solver ([RCWA or any other solver of Maxwell equations from [0081]) based on first assumed values of one or more parameters of interest characterizing a shape of the structure under measurement ([0093-0094]: “FIG. 9 illustrates a parameterized mathematical model 900 of the target structure 800 shown in FIG. 8. Only the repeating unit need be modeled explicitly, in a case where the target structure is periodic. Substrate layer 802 is represented by substrate model 902. First sub-structure 804 is represented by first sub-structure model 904 and second substructure 806 is represented by second sub-structure model 906. Each of these sub-structure models is defined by a set of dimension and shape parameters. Just for the sake of this example, the first sub-structure model is defined by a height h1, a width CD1, a left side wall angle SWAL1 and a right side wall angle SWAR1. The second sub-structure model is defined by corresponding parameters h2, CD2, SWAL2 and SWAR2. Each of these parameters can be considered as a (fixed or floating) parameter p.sub.i in the reconstruction method of FIG. 5. Another parameter d12 defines a distance between them. (As shown in FIG. 8, their arrangement may not be exactly equal.)”; See first candidate structure from [0075]);
estimate a first reflectivity of the structure under measurement based on a coherent sum of the simulated first reflectivity associated with each substructure of the structure under measurement ([0075]: Estimate of target shape (a first candidate structure) is calculated where the target structure may be a 1D or 2D array of substructures on a substrate.; [0081]:” In step 506, the parameters representing the estimated shape, together with the optical properties of the different elements of the model, are used to calculate the scattering properties, for example using a rigorous optical diffraction method such as RCWA or any other solver of Maxwell equation.”);
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify Madsen so that the structure under measurement includes a plurality of substructures; and
one or more computer systems configured to:
simulate a first reflectivity of each substructure of the structure under measurement using an electro-magnetic solver based on first assumed values of one or more parameters of interest characterizing a shape of the structure under measurement;
estimate a first reflectivity of the structure under measurement based on a coherent sum of the simulated first reflectivity associated with each substructure of the structure under measurement, as disclosed by Dirks. Simulating and estimating parameters associated with substructures using an electro-magnetic solved is known in the field of endeavor. Therefore, one of ordinary skill in the art would have found it obvious to combine prior art elements (simulating and estimating parameters associated with substructures using an EM solver) according to known methods (RCWA is suitable for periodic structures [0006] from Dirks).) to yield predictable results (as a calculation method for simulating interaction of radiation with different structures (from [0006] of Dirks).) (MPEP 2143 (I)(A)).
Madsen modified by Dirks appears to be silent to having an aspect ratio of the structure under measurement be at least 10.
Bauer et al (“Very high aspect ratio through silicon via reflectometry”, June 2017, SPIE, Vol. 10329), related to reflectometry, does teach having an aspect ratio of the structure under measurement be at least 10 (Abstract: Aspect ratio of 35:1).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify Madsen combined with Dirks so that an aspect ratio of the structure under measurement is at least 10, as disclosed by Bauer et al. Structures with high aspect ratios opens up the potential of smaller packaging, stress reduction, and low costs for advanced 3D integration (page 1, first paragraph of Introduction). Therefore, one of ordinary skill in the art would have found motivation to be able to have their apparatus measure structures with an aspect ratio of at least 10.
Regarding Claims 3 and 14, Madsen modified by Dirks and Bauer et al teaches the metrology system of Claim 1 and method of Claim 12.
Madsen modified by Dirks and Bauer et al further teaches that the structure (Madsen, periodic structure from [0141]) under measurement is characterized by a spatial periodicity of at least five micrometers (Madsen, [0141]: All steps/pitches are possible, e.g., from 50 nm to the mm range which includes at least 5 micrometers.).
Regarding Claims 4 and 15, Madsen modified by Dirks and Bauer et al teaches the metrology system of Claim 3 and method of Claim 14.
Madsen modified by Dirks and Bauer et al further teaches that a size of the first measurement spot (Madsen, illuminating spot size from [0024]) on the surface of the specimen is at least twice the spatial periodicity of the structure under measurement (Madsen, [0024]: Illuminating spot size is greater than 10 microns. From [0141], all pitches are possible, from 50 nm to the mm range. Therefore, substructures having a pitch of 5 microns would allow for the illuminating spot size to be at least twice the spatial periodicity (pitch/step) of the structure under measurement.).
Regarding Claim 5, Madsen modified by Dirks and Bauer et al teaches the metrology system of Claim 1.
Madsen modified by Dirks and Bauer et al further teaches that a size of the first measurement spot on the surface of the specimen is at least 20 micrometers (Madsen, [0024]: Illuminating spot size is greater than 10 microns, e.g., not less than 0.1 mm, and not less than 0.5 mm. This range includes 20 microns.).
Regarding Claim 6, Madsen modified by Dirks and Bauer et al teaches the metrology system of Claim 1.
Madsen modified by Dirks and Bauer et al further teaches that the first amount of broadband illumination light includes wavelengths spanning a range from 550 nanometers to 850 nanometers (Madsen, [0086-0088]: The broadband light source covers a range of at least 100 nm to at least 800 nm.).
Regarding Claim 7, Madsen modified by Dirks and Bauer et al teaches the metrology system of Claim 1.
Madsen modified by Dirks and Bauer et al further teaches that the structure under measurement is a trench structure or a hole structure (Madsen, [0026]: Dimensional information of a diameter and/or roundness of holes can be determined.).
Regarding Claims 8 and 16, Madsen modified by Dirks and Bauer et al teaches the metrology system of Claim 1 and method of Claim 12.
Madsen modified by Dirks and Bauer et al (for claim 1) appears to be silent to a polarization of the first amount of broadband illumination light incident on the first measurement spot is transverse magnetic or transverse electric.
Madsen, in another embodiment, does teach a polarization of the first amount of broadband illumination light incident on the first measurement spot is transverse magnetic or transverse electric ([0193-0200]: “Scattering measurements without the use of a reference signal can be performed by measuring both TE- and TM-polarized light in the same sample region of interest.” “A Wollaston polarizer 38 is used to separate the incoming light into its TE (transverse electric) and TM (transverse components ([0200]).”.
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify Madsen combined with Dirks and Bauer et al (for claim 1) so that a polarization of the first amount of broadband illumination light incident on the first measurement spot is transverse magnetic (TM) or transverse electric (TE), as disclosed by Madsen. The advantage of using TE- and TM-polarized light is that scattering measurements can be performed without use of a reference signal ([0193] from Madsen).
Regarding Claims 10 and 18, Madsen modified by Dirks and Bauer et al teaches the metrology system of Claim 1 and method of Claim 12.
Madsen modified by Dirks and Bauer et al further teaches that the one or more computing systems (Madsen, [0028]: Computer simulations would necessarily require some sort of computing system.) is further configured to:
estimate the first assumed value of a parameter of interest characterizing a depth of a deep, large pitch structure (Madsen, height of side walls and diameters of holes from [0026]) under measurement based on an estimated number of electromagnetic signal oscillations required to probe a depth of the deep, large pitch target (Madsen, [0164-0165]: Models are modeled with dimensional parameters such as variations in height, width, and angle of the sidewall where an RCWA algorithm is used. RCWA is a frequency-domain method for solving Maxwell’s equations in periodic structures where solving Maxwell’s equations necessarily involve electromagnetic signal oscillations.).
Regarding Claim 11, Madsen modified by Dirks and Bauer et al teaches the metrology system of Claim 1.
Madsen modified by Dirks and Bauer et al further teaches that an illumination Numerical Aperture (NA) of the SR subsystem is between 0.04 and 0.08 (Madsen, [0050]: The numerical aperture number can have a numerical value in the range of 0.01 to 0.30) and wherein a collection NA of the SR subsystem is between 0.01 and 0.04 (Madsen, [0050]: The numerical aperture number can have a numerical value in the range of 0.01 to 0.30).
Claims 2, 13, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Madsen (WO 2016015734 A1, with portions cited below from an attached translation) in view of Dirks (US 2017/0017738 A1) and Bauer et al (“Very high aspect ratio through silicon via reflectometry”, June 2017, SPIE, Vol. 10329), and further in view of Brill (WO 2011117872 A1, with portions cited below from an attached translation).
Regarding Claims 2, 13, and 20 Madsen modified by Dirks and Bauer et al teaches the metrology system of Claim 1, method of Claim 12, and metrology system of Claim 19.
Madsen modified by Dirks and Bauer et al further teaches that the one or more computing systems (Madsen, [0028]: Computer simulations would necessarily require some sort of computing system.) and the non-transitory, computer-readable medium further storing instructions that, when executed by one or more processors, causes the one or more processors to:
simulate a second reflectivity of each substructure of the structure under measurement (Dirks, Fig. 2: Trenches 264 and 266 are substructures of target structure 260 ([0061].) using the electro-magnetic solver (Madsen, RCWA (rigorous coupled wave analysis) from [0163-0164]; [0175]) based on second assumed values of one or more parameters of interest characterizing the shape (Madsen, [0165]: Models are modeled with dimensional parameters (height, width, and angle).) of the structure under measurement (Madsen, Shown in Fig. 8 which describes an iterative process ([0169-0170] and [0034]). The iterative process involves global optimization with electromagnetic solver model for diffraction efficiencies with convergence check (simulate a second reflectivity).);
estimate a second reflectivity (Madsen, shown in Fig. 8 and described in [0169-0170] and [0034] where diffraction efficiencies are estimated using an electromagnetic solver model) of the structure under measurement based on a coherent sum of the simulated second reflectivity (Madsen, [0164-0167]: RCWA algorithm, which is a Maxwell equation solver, calculates the phase-sensitive amplitudes of electromagnetic waves which are a superposition of electric and magnetic waves. Therefore, RCWA necessarily includes coherent summation.) associated with each substructure of the structure under measurement (Dirks, Fig. 2: Trenches 264 and 266 are substructures of target structure 260 ([0061].) (Madsen, Shown in Fig. 8 which describes an iterative process ([0169-0170] and [0034]). The iterative process involves a theoretical profile match with the actual profile.); and
generate a second set of updated values of the one or more parameters of interest (Madsen, Fig. 8: Find best set of parameters from database look up.) based on a difference between the measured reflectivity and estimated second reflectivity of the structure (Madsen, Shown in Fig. 8 where the iterative process involves an optimize fit (difference between the measured value and estimated value) and check for convergence.).
Madsen modified by Dirks and Bauer et al appears to be silent to estimating a second reflectivity of the structure under measurement based on an incoherent sum of the simulated second reflectivity.
Brill, related to a measurement system and method for measuring properties of a structure having a pattern of spaced apart features, does teach incoherent summation in computations using RCWA ([0056]).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify Madsen combined with Dirks and Bauer et al to incorporate estimating a second reflectivity of the structure under measurement based on an incoherent sum of the simulated second reflectivity, as disclosed by Brill. Using coherent or non-coherent integration in RCWA computation is known in the field of endeavor. Therefore, one of ordinary skill in the art would have found it obvious to combine prior art elements (using coherent or incoherent summation) according to known methods (in RCWA computation) to yield predictable results (for measuring properties of a structure having a pattern) (MPEP 2143 (I)(A)).
Claims 9 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Madsen (WO 2016015734 A1, with portions cited below from an attached translation) in view of Dirks (US 2017/0017738 A1) and Bauer et al (“Very high aspect ratio through silicon via reflectometry”, June 2017, SPIE, Vol. 10329), and further in view of Webster (US 20240189938 A1).
Regarding Claims 9 and 17, Madsen modified by Dirks and Bauer et al teaches the metrology system of Claim 1 and method of Claim 12.
Madsen modified by Dirks and Bauer et al further teaches that the one or more computing systems (Madsen, [0028]: Computer simulations would necessarily require some sort of computing system.) is further configured to:
estimate the first assumed value of a parameter of interest characterizing a depth of a deep, large pitch structure (Madsen, height of side walls and diameters of holes from [0026]) under measurement based on an analysis of the measured spectral signals (Madsen, [0164-0165]: Models are modeled with dimensional parameters such as variations in height, width, and angle of the sidewall where an RCWA algorithm is used which is based on calculating the diffraction of individual plates and then connecting each plate to each other through boundary conditions.), wherein the analysis involves mapping the measured spectral signals to an inverse wavelength domain (Madsen, [0164-0165]: RCWA is a Fourier-space method which analyzes problems by converting the measured spectral signals into a space of frequencies/inverse wavelength.)
Madsen modified by Dirks and Bauer et al appears to be silent to transforming the mapped spectral signals to express measured reflectivity as a function of optical distance.
Webster, related to measuring depth, does teach transforming the mapped spectral signals (spectral interferogram from [0317]) to express measured reflectivity as a function of optical distance (depth-reflectivity profile from [0317]) ([0317]: “To extract depth information, the spectral interferogram (measured with a spectrometer) may be resampled to units of constant wavenumber by interpolation and may be transformed to I(z) via FFT. The resulting function (known as an A-scan or A-line) is a depth-reflectivity profile of the sample (shown in logarithmic units relative to the noise floor) with each reflecting interface in the sample appearing as a point spread function (PSF) centered about its depth.”).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify Madsen combined with Dirks and Bauer et al to incorporate transforming the mapped spectral signals to express measured reflectivity as a function of optical distance, as disclosed by Webster. The above-mentioned process has the advantage of allowing for the extraction of depth information ([0317] from Webster).
Conclusion
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/JUDY DAO TRAN/Examiner, Art Unit 2877
/MICHELLE M IACOLETTI/Supervisory Patent Examiner, Art Unit 2877
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