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 § 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 – 7, and 12 – 18 are rejected under 35 U.S.C. 103 as being unpatentable over US20090146259A1 (Jessen) and in view of US20130003031A1 (Hofmans).
In regards to claim 1 (Jessen) shows:
A non-transitory computer readable medium having instructions therein the instructions, when executed by a computer system, configured to cause the computer system to at least: Jessen [0050] teaches computer readable medium can be provided that configures a processor to perform a method for forming a mask having OPC.
add, based on the two or more different focus positions, one or more assist features to a pattern in one or more locations proximate to one or more target features of the pattern; Jessen [0037] teaches SRAFs positioned adjacent to a mask feature. Jessen [0038] teaches the SRAF spacing from the mask features will vary depending on the proximity of one mask feature to another mask feature.
the added one or more assist features configured to enhance the one or more target features on the substrate; Jessen [0032] teaches SRAFs can be added to any side of a mask pattern to improve the sharpness of the mask pattern.
Jessen differs from the claimed invention in that it does not explicitly disclose determine two or more different focus positions on a substrate for imaging radiation;
Hofmans teaches determine two or more different focus positions on a substrate for imaging radiation; Hofmans [0047] teaches a method of measuring focus of a lithographic projection apparatus where a wafer is exposed with full wafer coverage verification fields at a predetermined optimal focus offset FO. Hofmans [0052] teaches that calibration fields are exposed where tilts will make rows/columns of calibration marks within the calibration fields to be exposed at different focus height.
The motivation to combine Jessen and Hofmans at the effective filing date of the invention is to enhance lithographic mask design by incorporating focus measurement capabilities with SRAF placement optimization to improve overall pattern fidelity across different focus conditions.
In regards to claim 2 (Jessen) does not show the medium of claim 1, wherein the two or more different focus positions on the substrate are for imaging radiation having two or more different wavelengths, and are determined for a single exposure of the substrate to the imaging radiation:
Hofmans teaches wherein the two or more different focus positions on the substrate are for imaging radiation having two or more different wavelengths; Hofmans [0065] teaches the terms "radiation" and "beam" used herein encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation and extreme ultra-violet (EUV) radiation, as well as particle beams, such as ion beams or electron beams.
Hofmans teaches are determined for a single exposure of the substrate to the imaging radiation; Hofmans [0043] teaches in step mode, the mask table MT and the substrate table WT are kept essentially stationary, while an entire pattern imparted to the radiation beam is projected onto a target portion C at one time. Hofmans [0044] teaches in scan mode, the mask table MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam is projected onto a target portion C.
The motivation to combine Jessen and Hofmans at the effective filing date of the invention is to enhance lithographic mask design by incorporating focus measurement capabilities with SRAF placement optimization to improve overall pattern fidelity across different focus conditions.
In regards to claim 3 (Jessen) shows the medium of claim 1:
wherein the one or more assist features comprise one or more sub-resolution assist features; Jessen [0032] teaches sub-resolution assist feature SRAF understood to be features that may be too narrow to be resolved by the optical lithographic system.
In regards to claim 4 (Jessen) shows the medium of claim 1:
wherein the added one or more assist features are configured to enhance the one or more target features on the substrate by improving a symmetry of target features of the pattern, and/or placement of target features of the pattern, on the substrate; Jessen [0039] teaches by varying the spacing of the SRAFs from the mask features, the aspect ratio of the printed pattern can be controlled and the SRAF spacing changes the aerial image of the feature in question in such a way as to allow the feature to print symmetrically. Jessen [0040] teaches varying the SRAF spacing can provide printed features such as a contact hole that have substantially symmetric aspect ratios.
In regards to claim 5 (Jessen) shows the medium of claim 1, wherein the instructions are further configured to cause the computer system to:
place the one or more assist features into the pattern in the one or more locations proximate to the one or more target features; Jessen [0037] teaches SRAFs positioned adjacent to a mask feature.
determine the aerial image based on the one or more placed assist features and the one or more target features; Jessen [0041] teaches SRAF spacings may be adjusted according to a model based environment where the optimal placement of the SRAF can be determined by an aerial image analysis.
In regards to claim 6 (Jessen) shows the medium of claim 5:
wherein symmetry of one or more target features of the pattern, and/or placement of one or more target features of the pattern, in the aerial image is improved relative to a symmetry and/or placement of target features in a different image determined without considering the one or more assist features; Jessen [0039] teaches the SRAF spacing changes the aerial image of the feature in question in such a way as to allow the feature to print symmetrically which demonstrates that symmetry in the aerial image is improved through assist feature placement compared to an image without assist features.
In regards to claim 7 (Jessen) shows the medium of claim 1:
wherein the instructions configured to cause the computer system to add the one or more assist features to the pattern in the one or more locations proximate to the one or more target features of the pattern are further configured to cause the computer system to determine a shape, a size, a position, and/or an orientation of the one or more assist features relative to the one or more target features; Jessen [0037] teaches SRAFs positioned adjacent to a mask feature with varying spacing distances. Jessen [0038] teaches the various mask features and SRAFs can be arranged in any configuration.
In regards to claim 12 (Jessen) shows the medium of claim 1:
wherein a shape, size, position, and/or orientation of the one or more assist features are configured such that the one or more assist features are not formed on the substrate; Jessen [0032] teaches the term sub-resolution assist feature (SRAF) is understood to be features that may be too narrow to be resolved by the optical lithographic system, inherently teaching that these assist features are not formed on the substrate due to their sub-resolution nature.
In regards to claim 13 (Jessen) shows the medium of claim 1:
wherein the instructions configured to cause the computer system to add the one or more assist features to the pattern in the one or more locations proximate to the one or more target features of the pattern are further configured to cause the computer system to electronically model the one or more assist features in the pattern. Jessen [0041] teaches that SRAF spacings may be adjusted according to a model based environment where the optimal placement of the SRAF can be determined by an aerial image analysis, specifically teaching that SRAFs are electronically modeled in a model-based environment. Jessen [0041] further teaches this analysis can involve the predicted CD in y and x directions, demonstrating the electronic modeling of the assist features in the pattern.
In regards to claim 14 (Jessen) shows:
A method to enhance a process of imaging a portion of a design layout onto a substrate, the method comprising: Jessen [0050] teaches method for forming a mask having OPC.
placing, by a hardware computer system based on the two or more different focus positions, one or more assist features asymmetrically into the design layout for imaging in one or more locations proximate to a target feature in the design layout for imaging; Jessen [0037] teaches SRAFs spaced at different distances or nonequidistant from mask features with examples where S1 does not equal S2 does not equal S3. Jessen [0050] teaches computer readable medium configures a processor to perform a method.
Jessen differs from the claimed invention in that it does not explicitly disclose determining two or more different focus positions on the substrate for imaging radiation;
Hofmans teaches determining two or more different focus positions on the substrate for imaging radiation; Hofmans [0047] teaches a method of measuring focus of a lithographic projection apparatus where a wafer is exposed with full wafer coverage verification fields at a predetermined optimal focus offset FO. Hofmans [0052] teaches that calibration fields are exposed where tilts will make rows/columns of calibration marks within the calibration fields to be exposed at different focus height.
The motivation to combine Jessen, and Hofmans at the effective filing date of the invention is to enhance lithographic pattern imaging by integrating asymmetric assist feature placement techniques with precise focus positioning methods to improve overall imaging quality and pattern fidelity.
In regards to claim 15 (Jessen) shows the medium of claim 14:
further comprising causing the one or more target features of the design layout to be imaged onto the substrate based on the one or more placed assist features and the one or more target features; Jessen [0049] teaches IC can be formed by exposing a mask to a source of radiation or beam.
In regards to claim 16 (Jessen) does not show the medium of claim 14, wherein the two or more different focus positions on the substrate are for imaging radiation having two or more different wavelengths, and are determined for a single exposure of the substrate to the imaging radiation:
Hofmans teaches wherein the two or more different focus positions on the substrate are for imaging radiation having two or more different wavelength; Hofmans [0065] teaches the terms "radiation" and "beam" used herein encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation and extreme ultra-violet (EUV) radiation, as well as particle beams, such as ion beams or electron beams.
Hofmans teaches are determined for a single exposure of the substrate to the imaging radiation; Hofmans [0043] teaches in step mode, the mask table MT and the substrate table WT are kept essentially stationary, while an entire pattern imparted to the radiation beam is projected onto a target portion C at one time. Hofmans [0044] teaches in scan mode, the mask table MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam is projected onto a target portion C.
The motivation to combine Jessen and Hofmans at the effective filing date of the invention is to enhance lithographic mask design by incorporating focus measurement capabilities with SRAF placement optimization to improve overall pattern fidelity across different focus conditions.
In regards to claim 17 (Jessen) shows the medium of claim 14:
wherein the placed one or more assist features are configured to enhance the one or more target features on the substrate by improving a symmetry of one or more target features of the design layout, and/or placement of one or more target features of the design layout, on the substrate; Jessen [0039] teaches SRAF spacing changes the aerial image of the feature in question in such a way as to allow the feature to print symmetrically. Jessen [0040] teaches varying the SRAF spacing can provide printed features such as a contact hole that have substantially symmetric aspect ratios which demonstrates that assist features enhance target features by improving their symmetry on the substrate.
In regards to claim 18 (Jessen) shows the medium of claim 14:
further comprising determining an aerial image associated with the substrate using the placed one or more assist features and the one or more target features; Jessen [0041] teaches SRAF spacings may be adjusted according to a model based environment where the optimal placement of the SRAF can be determined by an aerial image analysis.
Claims 8, 11, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over US20090146259A1 (Jessen) in view of US20130003031A1 (Hofmans) as applied to Claims 1 and 14 above, respectively, and further in view of US20090091726A1 (KALF).
In regards to claim 8 (Jessen modified by Hofmans) shows the medium of claim 1:
wherein the addition of the one or more assist features to the pattern enhances the one or more target features ; Jessen [0032] teaches that SRAFs can be added to any side of a mask pattern to improve the sharpness of the mask pattern. Jessen [0039] teaches that by varying the spacing of the SRAFs from the mask features, the aspect ratio of the printed pattern can be controlled and the SRAF spacing changes the aerial image of the feature in question in such a way as to allow the feature to print symmetrically.
Jessen modified by Hofmans differs from the claimed invention in that it does not explicitly disclose by reducing a shift caused by across slit asymmetry for a slit of a multifocal lithographic imaging apparatus.
KALF teaches by reducing a shift caused by across slit asymmetry for a slit of a multifocal lithographic imaging apparatus; KALF [0051] teaches that a splitter splits transmitted light beam portion into a first sub-beam associated with a first optical branch and a second sub-beam associated with a second optical branch where each optical branch has a back focal plane corresponding with the objective lens. KALF [0057] teaches that because two sub-beams are used to determine if substrate is in focus, it is possible to determine in which direction the distance between substrate and objective lens should be changed to get substrate in optimal position relative to the objective lens.
The motivation to combine Jessen, Hofmans, and KALF at the effective filing date of the invention is to integrate SRAF pattern enhancement with focus detection and correction capabilities to address position-dependent optical effects and asymmetries in advanced lithographic imaging systems.
In regards to claim 11 (Jessen modified by Hofmans) does not show the medium of claim 8, wherein different ones of the one or more assist features correspond to one or more different slit positions in the slit:
Kalf teaches wherein different ones of the one or more assist features correspond to one or more different slit positions in the slit; KALF [0051] teaches that a splitter splits transmitted light beam portion into a first sub-beam associated with a first optical branch and a second sub-beam associated with a second optical branch where each optical branch represents different positional elements within the optical system corresponding to different spatial locations.
The motivation to combine Jessen, Hofmans, and KALF at the effective filing date of the invention is to integrate position-dependent assist feature placement techniques with focus measurement capabilities and optical branch positioning systems to provide comprehensive correction of spatial variations and asymmetries across different locations within the lithographic imaging apparatus, thereby improving pattern fidelity and addressing position-specific optical effects that vary across the imaging field.
In regards to claim 19 (Jessen modified by Hofmans) shows the medium of claim 14:
wherein the placing of the one or more assist features enhances the one or more target features; Jessen [0032] teaches that SRAFs can be added to any side of a mask pattern to improve the sharpness of the mask pattern. Jessen [0039] teaches that by varying the spacing of the SRAFs from the mask features, the aspect ratio of the printed pattern can be controlled and the SRAF spacing changes the aerial image of the feature in question in such a way as to allow the feature to print symmetrically.
Jessen modified by Hofmans differs from the claimed invention in that it does not explicitly disclose by reducing a shift caused by across slit asymmetry for a slit of a multifocal lithographic imaging apparatus.
KALF teaches by reducing a shift caused by across slit asymmetry for a slit of a multifocal lithographic imaging apparatus; KALF [0051] teaches that a splitter splits transmitted light beam portion into a first sub-beam associated with a first optical branch and a second sub-beam associated with a second optical branch where each optical branch has a back focal plane corresponding with the objective lens. KALF [0057] teaches that because two sub-beams are used to determine if substrate is in focus, it is possible to determine in which direction the distance between substrate and objective lens should be changed to get substrate in optimal position relative to the objective lens.
The motivation to combine Jessen, Hofmans, and KALF at the effective filing date of the invention is to integrate advanced SRAF enhancement techniques with focus measurement and optical correction capabilities to address complex imaging challenges including position-dependent asymmetries in multifocal lithographic systems.
Claims 9, 10, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over US20090146259A1 (Jessen) modified by US20130003031A1 (Hofmans) and US20090091726A1 (KALF) as applied to claims 8 and 19 above, respectively, and further in view of US20090306921A1 (Totzeck).
In regards to claim 9 (Jessen modified by Hofmans and KALF) does not show the medium of claim 8, wherein the across slit asymmetry is associated with a Z2 Zernike polynomial:
Totzeck teaches wherein the across slit asymmetry is associated with a Z2 Zernike polynomial; Totzeck [0073] teaches that imaging errors stemming from the scalar phase are well understood and conveniently described by an expansion of the wavefront phase over pupil into Zernike polynomials where single Zernike polynomials correspond to particular imaging errors. Totzeck [0078] teaches a numbering scheme for Zernike polynomials including specific polynomial designations such as Z2 which can be used to characterize specific types of optical aberrations and imaging errors.
The motivation to combine Jessen, Hofmans, KALF, and Totzeck at the effective filing date of the invention is to provide a complete optical characterization system that combines SRAF placement with focus control and Zernike polynomial analysis to systematically address and correct specific imaging aberrations including asymmetric effects.
In regards to claim 10 (Jessen modified by Hofmans and KALF) does not show the medium of claim 8, wherein the across slit asymmetry is associated with collateral Zernike polynomials:
Totzeck teaches wherein the across slit asymmetry is associated with collateral Zernike polynomials; Totzeck [0074] teaches that scalar Zernike polynomials can be used for transmission and rotation expansion and that for diattenuation and retardance which consist of magnitude and direction the Zernike polynomials have to be modified into different forms. Totzeck [0101] teaches orientation Zernike polynomials OZP as an expansion for orientator fields with various azimuthal indices m which demonstrates the use of related or collateral polynomial expansions for different optical effects.
The motivation to combine Jessen, Hofmans, KALF, and Totzeck at the effective filing date of the invention is to create an advanced lithographic correction system that utilizes SRAF techniques alongside focus measurement and multiple Zernike polynomial characterization methods to comprehensively address various forms of optical aberrations and asymmetries.
In regards to claim 20 (Jessen modified by Hofmans and KALF) does not show the medium of claim 19, wherein the across slit asymmetry is associated with a Z2 Zernike polynomial or associated with collateral Zernike polynomials:
Totzeck teaches wherein the across slit asymmetry is associated with a Z2 Zernike polynomial or associated with collateral Zernike polynomials; Totzeck [0073] teaches that imaging errors stemming from the scalar phase are well understood and conveniently described by an expansion of the wavefront phase over pupil into Zernike polynomials where single Zernike polynomials correspond to particular imaging errors. Totzeck [0078] teaches a numbering scheme for Zernike polynomials including specific polynomial designations such as Z2 which can be used to characterize specific types of optical aberrations and imaging errors.
The motivation to combine Jessen, Hofmans, KALF, and Totzeck at the effective filing date of the invention is to provide a complete lithographic optimization system that combines assist feature placement with focus control and systematic aberration characterization using Zernike polynomial analysis to address specific optical imaging errors and asymmetries.
Response to Argument
Applicant's arguments filed on December 3, 2025 have been fully considered but they are not persuasive.
Applicant argues that Hofmans fails to teach "add, based on the two or more different focus positions, one or more assist features" because Hofmans only describes measuring focus that occurred during exposure, not designing patterns for multiple focuses. Applicant further argues that the mark in Hofmans is designed for a single particular focus and would not work for multiple focus positions.
However, the examiner respectfully disagrees. Hofmans [0047] and [0052] teach determining multiple different focus positions by exposing calibration fields at different focus heights. Jessen [0037-0038] teaches adding SRAFs adjacent to mask features with varying spacing. When combined, these references teach determining multiple focus positions and adding assist features based on those positions. The combination is motivated by the desire to improve lithographic pattern fidelity across different focus conditions that naturally occur during manufacturing.
Applicant's assertion that Hofmans' measurement mark cannot be designed for multiple focuses mischaracterizes the combination. The obviousness analysis does not require that Hofmans' measurement marks themselves serve multiple focuses. Rather, the knowledge of how different focus positions affect features, derived from Hofmans' methodology, would inform assist feature placement in production patterns as taught by Jessen. This represents proper obviousness analysis under 35 U.S.C. § 103, where references are combined to teach claimed limitations even when individual references do not explicitly disclose every element.
Applicant's argument that there is no teaching in Hofmans regarding adding assist features improperly treats references in isolation. Under MPEP 2141.01(a), references are properly combined when they address related problems. Both Hofmans and Jessen address lithographic pattern optimization, making their combination appropriate. Jessen provides SRAF placement methodology while Hofmans provides understanding of multiple focus positions. The combination would lead a person of ordinary skill to optimize SRAF placement based on multiple focus positions.
Additionally, Applicant has provided no substantive response to the obviousness rejections for claims 8-11, 19-20 beyond asserting that Wildenberg fails to overcome deficiencies. These arguments do not address the specific teachings of KALF and Totzeck regarding position-dependent optical effects and Zernike polynomial characterization. These rejections remain fully supported by the cited combinations.
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 ANWER AHMED ALAWDI whose telephone number is (703)756-1018. The examiner can normally be reached Monday - Friday 8:00 am - 5:30 pm.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jack Chiang can be reached on (571)-272-7483. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/ANWER AHMED ALAWDI/Examiner, Art Unit 2851
/JACK CHIANG/Supervisory Patent Examiner, Art Unit 2851