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, 4 – 6, 8, 11 – 13, 15, 18, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over US20160077426A1 (Jang) in view of US7080349B1 (Babcock) and further in view of US20130080982A1 (Word).
In regards to claim 1 (Jang) shows an optical proximity correction method comprising:
calculating a plurality of chief ray angles of a plurality of points of interest on the mask design, respectively; Jang [0033] teaches that EUV light incident on the mask acquires a position-dependent chief ray angle as it passes through a curved slit, with each point of interest on the mask design having a corresponding angle of incidence. Jang [0059-0066] further teaches calculating the chief ray angle at each of thirteen distinct points of interest across the mask design, with values ranging from 67° to 113° according to the specific position within the mask design.
wherein each of the plurality of points of interest has a corresponding distance from the reference point; Jang [0066] teaches dividing a slit into thirteen regions where each region has a specific position corresponding to a measured distance from the reference point, establishing a one-to-one mapping between each point of interest and its distance from the reference.
finding, among the plurality of points of interest on the mask design, a first point of interest having a maximum chief ray angle among the plurality of chief ray angles; Jang [0068] teaches identifying the point of interest having the largest angular deviation from the center region — i.e., the region with the maximum chief ray angle variation — as the area requiring separate TCC calculations due to its maximum deviation from the reference.
Jang differs from the claimed invention in that it does not explicitly disclose designing a mask design, wherein the designing of the mask design comprises: setting a reference point of the mask design; wherein each chief ray angle of the plurality of chief ray angles is an incidence angle of a chief ray at a corresponding point of interest with respect to a vertical direction of a plane on which the mask design is formed; wherein a distance of the first point of interest from the reference point is set as a deteriorated distance; compensating for distortion of an image to be transferred from a pattern located at the deteriorated distance from the reference point of the mask design.
Babcock teaches designing a mask design, wherein the designing of the mask design comprises: setting a reference point of the mask design; Babcock [Column 6 Lines 5 - 15] teaches generating a test pattern layout that sets reference points for OPC simulation.
Babcock teaches wherein a distance of the first point of interest from the reference point is set as a deteriorated distance; Babcock [Column 12 Lines 5 - 15] teaches identifying specific distances from the reference test pattern layout where optical problems occur, by analyzing which simulated printed layouts fall within specification limits and designating those distances as requiring special OPC handling due to deteriorated print quality — establishing the concept of a deteriorated distance measured from the reference point.
Babcock teaches compensating for distortion of an image to be transferred from a pattern located at the deteriorated distance from the reference point of the mask design; Babcock [Column 4 Lines 15 - 25] teaches fragmenting edges of patterns and manipulating those fragments to account for optical proximity effects.
Babcock differs from the claimed invention in that it does not explicitly disclose wherein each chief ray angle of the plurality of chief ray angles is an incidence angle of a chief ray at a corresponding point of interest with respect to a vertical direction of a plane on which the mask design is formed.
Word teaches wherein each chief ray angle of the plurality of chief ray angles is an incidence angle of a chief ray at a corresponding point of interest with respect to a vertical direction of a plane on which the mask design is formed; Word [0003] teaches that in an EUV lithography system the chief ray is off-axis by approximately 6 degrees at the mask plane, and that the system is non-telecentric at the mask plane — establishing that the chief ray arrives at the mask design at a non-perpendicular incidence angle. Word [0049] establishes a coordinate system for the mask plane defined by a horizontal axis H and a vertical axis V, with the inclination angle of illumination measured from the normal of the mask plane, and further teaches that layout features on the mask are illuminated at different angles depending on their position in the illuminated field — establishing that the chief ray angle at each point of interest on the mask design is an incidence angle measured with respect to the vertical direction of the plane on which the mask design is formed.
The motivation to combine Jang and Babcock at the effective filing date of the invention is to improve the accuracy of optical proximity correction by integrating Jang's position-dependent angle calculations with Babcock's systematic approach to identifying and compensating for problem areas in mask designs. The motivation to combine Jang, Babcock, and Word at the effective filing date of the invention is to create a more effective photolithography process by integrating complementary optical proximity correction techniques to enhance mask design precision and pattern transfer accuracy.
In regards to claim 4 (Jang) shows the method of claim 1:
wherein the compensating for the distortion of the image to be transferred from the pattern located at the deteriorated distance includes: performing optical proximity correction on the pattern located at the deteriorated distance from the reference point; Jang [0046] teaches generating OPC models reflecting corresponding TCCs and comparing simulated mask patterns with target patterns.
In regards to claim 5 (Jang) shows the method of claim 1:
wherein the reference point is disposed at a center of the mask design; Jang [0082] teaches that the reference point is located at the center of the slit, with divided regions arranged symmetrically about the center reference point.
In regards to claim 6 (Jang) shows the method of claim 1:
wherein the reference point is disposed at an edge of the mask design; Jang [0079] teaches dividing the slit into regions of different widths that extend to positions at the edge of the slit, establishing that the reference point may be disposed at an edge position of the mask design.
In regards to claim 8 (Jang) shows an optical proximity correction method comprising:
designing a mask design, wherein the designing of the mask design comprises: Jang [0125] teaches performing semiconductor processes on wafers using EUV masks created through OPC methods, establishing that the OPC method comprises designing the mask design.
setting a plurality of zones on the mask design, wherein the plurality of zones are concentric with reference to the reference point; Jang [0074-0075] teaches dividing the slit into multiple regions where TCC calculations are performed for each region extending from the center.
calculating a plurality of chief ray angles of a plurality of points of interest on the mask design, respectively; Jang [0033] teaches that EUV light incident on the mask acquires a position-dependent chief ray angle as it passes through a curved slit, with each point of interest on the mask design having a corresponding angle of incidence. Jang [0059-0066] further teaches calculating the chief ray angle at each of thirteen distinct points of interest across the mask design, with values ranging from 67° to 113° according to the specific position within the mask design.
wherein each of the plurality of points of interest has a corresponding distance from the reference point; Jang [0066] teaches dividing a slit into thirteen regions where each region has a specific position corresponding to a measured distance from the reference point, establishing a one-to-one mapping between each point of interest and its distance from the reference.
finding, among the plurality of points of interest on the mask design, a first point of interest having a maximum chief ray angle among the plurality of chief ray angles; Jang [0068] teaches identifying the point of interest having the largest angular deviation from the center region — i.e., the region with the maximum chief ray angle variation — as the area requiring separate TCC calculations due to its maximum deviation from the reference.
setting, among the plurality of zones, a first zone where the first point of interest having the maximum chief ray angle is located as a deteriorated zone; Jang [0078] teaches performing TCC division of the slit based on measurement data to appropriate regions.
compensating for distortion of an image to be transferred from a pattern located in the deteriorated zone; Jang [0083] teaches performing OPC by reflecting TCCs of divided regions to fabricate masks with accurate patterns.
Jang differs from the claimed invention in that it does not explicitly disclose setting a reference point of the mask design; wherein each chief ray angle of the plurality of chief ray angles is an incidence angle of a chief ray at a corresponding point of interest with respect to a vertical direction of a plane on which the mask design is formed.
Babcock teaches setting a reference point of the mask design; Babcock [Column 6 Lines 5 - 15] teaches generating a test pattern layout that sets reference points for OPC simulation.
Babcock differs from the claimed invention in that it does not explicitly disclose wherein each chief ray angle of the plurality of chief ray angles is an incidence angle of a chief ray at a corresponding point of interest with respect to a vertical direction of a plane on which the mask design is formed.
Word teaches wherein each chief ray angle of the plurality of chief ray angles is an incidence angle of a chief ray at a corresponding point of interest with respect to a vertical direction of a plane on which the mask design is formed; Word [0003] teaches that in an EUV lithography system the chief ray is off-axis by approximately 6 degrees at the mask plane, and that the system is non-telecentric at the mask plane — establishing that the chief ray arrives at the mask design at a non-perpendicular incidence angle. Word [0049] establishes a coordinate system for the mask plane defined by a horizontal axis H and a vertical axis V, with the inclination angle of illumination measured from the normal of the mask plane, and further teaches that layout features on the mask are illuminated at different angles depending on their position in the illuminated field — establishing that the chief ray angle at each point of interest on the mask design is an incidence angle measured with respect to the vertical direction of the plane on which the mask design is formed.
The motivation to combine Jang and Babcock at the effective filing date of the invention is to enhance mask design quality by applying Babcock's structured reference point methodology to Jang's zone-based correction system, resulting in more precise identification of areas requiring compensation. The motivation to combine Jang, Babcock, and Word at the effective filing date of the invention is to create a more effective photolithography process by integrating complementary optical proximity correction techniques to enhance mask design precision and pattern transfer accuracy.
In regards to claim 11 (Jang) shows the method of claim 8:
wherein the compensating for the pattern located in the deteriorated zone includes: performing optical proximity correction on the pattern located in the deteriorated zone; Jang [0046] teaches generating OPC models reflecting corresponding TCCs and comparing simulated mask patterns with target patterns.
In regards to claim 12 (Jang) shows the method of claim 8:
wherein the reference point is disposed at a center of the mask design; Jang [0082] teaches that the reference point is located at the center of the slit, with divided regions arranged symmetrically about the center reference point.
In regards to claim 13 (Jang) shows the method of claim 8:
wherein the reference point is disposed at an edge of the mask design; Jang [0079] teaches dividing the slit into regions of different widths that extend to positions at the edge of the slit, establishing that the reference point may be disposed at an edge position of the mask design.
In regards to claim 15 (Jang) shows:
A photolithography method using a mask design on which an optical proximity correction method has been performed, the optical proximity correction method comprising designing the mask design; Jang [0125] teaches performing semiconductor processes on wafers using EUV masks created through OPC methods.
calculating a plurality of chief ray angles of a plurality of points of interest on the mask design, respectively; Jang [0033] teaches that EUV light incident on the mask acquires a position-dependent chief ray angle as it passes through a curved slit, with each point of interest on the mask design having a corresponding angle of incidence. Jang [0059-0066] further teaches calculating the chief ray angle at each of thirteen distinct points of interest across the mask design, with values ranging from 67° to 113° according to the specific position within the mask design.
wherein each of the plurality of points of interest has a corresponding distance from the reference point; Jang [0066] teaches dividing a slit into thirteen regions where each region has a specific position corresponding to a measured distance from the reference point, establishing a one-to-one mapping between each point of interest and its distance from the reference.
finding, among the plurality of points of interest on the mask design, a first point of interest having a maximum chief ray angle among the plurality of chief ray angles; Jang [0068] teaches identifying the point of interest having the largest angular deviation from the center region — i.e., the region with the maximum chief ray angle variation — as the area requiring separate TCC calculations due to its maximum deviation from the reference.
Jang differs from the claimed invention in that it does not explicitly disclose wherein the designing of the mask design comprises: setting a reference point of the mask design; wherein each chief ray angle of the plurality of chief ray angles is an incidence angle of a chief ray at a corresponding point of interest with respect to a vertical direction of a plane on which the mask design is formed; wherein a distance of the first point of interest from the reference point is set as a deteriorated distance; compensating for distortion of an image to be transferred from a pattern placed at the deteriorated distance from the reference point of the mask design.
Babcock teaches wherein the designing of the mask design comprises: setting a reference point of the mask design; Babcock [Column 6 Lines 5 - 15] teaches generating a test pattern layout that sets reference points for OPC simulation.
Babcock teaches wherein a distance of the first point of interest from the reference point is set as a deteriorated distance; Babcock [Column 12 Lines 5 - 15] teaches identifying specific distances from the reference test pattern layout where optical problems occur, by analyzing which simulated printed layouts fall within specification limits and designating those distances as requiring special OPC handling due to deteriorated print quality — establishing the concept of a deteriorated distance measured from the reference point.
Babcock teaches compensating for distortion of an image to be transferred from a pattern placed at the deteriorated distance from the reference point of the mask design; Babcock [Column 4 Lines 15 - 25] teaches fragmenting edges of patterns and manipulating those fragments to account for optical proximity effects.
Babcock differs from the claimed invention in that it does not explicitly disclose wherein each chief ray angle of the plurality of chief ray angles is an incidence angle of a chief ray at a corresponding point of interest with respect to a vertical direction of a plane on which the mask design is formed.
Word teaches wherein each chief ray angle of the plurality of chief ray angles is an incidence angle of a chief ray at a corresponding point of interest with respect to a vertical direction of a plane on which the mask design is formed; Word [0003] teaches that in an EUV lithography system the chief ray is off-axis by approximately 6 degrees at the mask plane, and that the system is non-telecentric at the mask plane — establishing that the chief ray arrives at the mask design at a non-perpendicular incidence angle. Word [0049] establishes a coordinate system for the mask plane defined by a horizontal axis H and a vertical axis V, with the inclination angle of illumination measured from the normal of the mask plane, and further teaches that layout features on the mask are illuminated at different angles depending on their position in the illuminated field — establishing that the chief ray angle at each point of interest on the mask design is an incidence angle measured with respect to the vertical direction of the plane on which the mask design is formed.
The motivation to combine Jang and Babcock at the effective filing date of the invention is to create a more effective photolithography process by incorporating Babcock's targeted correction techniques into Jang's comprehensive optical modeling framework. The motivation to combine Jang, Babcock, and Word at the effective filing date of the invention is to create a more effective photolithography process by integrating complementary optical proximity correction techniques to enhance mask design precision and pattern transfer accuracy.
In regards to claim 18 (Jang) shows the photolithography method of claim 15:
wherein the reference point is disposed at a center of the mask design; Jang [0082] teaches that the reference point is located at the center of the slit, with divided regions arranged symmetrically about the center reference point.
In regards to claim 19 (Jang) shows the photolithography method of claim 15:
wherein the reference point is disposed at an edge of the mask design; Jang [0079] teaches dividing the slit into regions of different widths that extend to positions at the edge of the slit, establishing that the reference point may be disposed at an edge position of the mask design.
Claims 7, 14, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over US20160077426A1 (Jang) in view of US7080349B1 (Babcock) and further in view of US20130080982A1 (Word) and further in view of US20100185998A1 (Wang).
In regards to claim 7 (Jang in view of Babcock in view of Word) does not show: wherein the compensating of the pattern comprises correcting a critical dimension of the pattern.
Wang teaches wherein the compensating of the pattern comprises correcting a critical dimension of the pattern; Wang [0018-0019] teaches measuring critical dimensions using mask error enhancement factor calculations and selecting target points that result in smaller MEEF for better image quality.
The motivation to combine Jang, Babcock, Word, and Wang at the effective filing date of the invention is to further enhance mask quality by adding Wang's critical dimension correction capabilities, which provides additional precision for correcting pattern dimensions at problematic areas identified through Jang's angle analysis and Babcock's reference point methodology.
In regards to claim 14 (Jang in view of Babcock in view of Word) does not show the method of claim 8: wherein the compensating of the pattern comprises correcting a critical dimension of the pattern.
Wang teaches wherein the compensating of the pattern comprises correcting a critical dimension of the pattern; Wang [0018-0019] teaches measuring critical dimensions using mask error enhancement factor calculations and selecting target points that result in smaller MEEF for better image quality.
The motivation to combine Jang, Babcock, Word, and Wang at the effective filing date of the invention is to further enhance mask quality by adding Wang's critical dimension correction capabilities, which provides additional precision for correcting pattern dimensions at problematic areas identified through Jang's angle analysis and Babcock's reference point methodology.
In regards to claim 20 (Jang in view of Babcock in view of Word) does not show the photolithography method of claim 15: wherein the compensating of the pattern comprises correcting a critical dimension of the pattern.
Wang teaches wherein the compensating of the pattern comprises correcting a critical dimension of the pattern; Wang [0018-0019] teaches measuring critical dimensions using mask error enhancement factor calculations and selecting target points that result in smaller MEEF for better image quality.
The motivation to combine Jang, Babcock, Word, and Wang at the effective filing date of the invention is to further enhance mask quality by adding Wang's critical dimension correction capabilities, which provides additional precision for correcting pattern dimensions at problematic areas identified through Jang's angle analysis and Babcock's reference point methodology.
Allowable Subject Matter
Claims 2, 3, 9, 10, 16, and 17 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitation of the base claim and any intervening claims.
Regarding claim 2, the prior art of record does not teach or suggest "wherein the plurality of chief ray angles are calculated using Equation 1: c6x^6 + c5x^5+c4x^4+c3x^3+c2x^2+c1x.... (1); where x represents a distance between a point of interest of the plurality of points of interest and the reference point, c6 is -0.2995, c5 is 3.083, c4 is -10.67, c3 is 13.44, c2 is -8.388, and c1 is 25.12" in combination with the other limitations of the claim.
Regarding claim 3, the prior art of record does not teach or suggest "calculating a plurality of chief ray angle shrinkages by substituting the plurality of chief ray angles into Equation 2, respectively: 2.930*tan(arcsin(sin(CRA*pi/180)/1.57755)); where CRA represents one of the plurality of chief ray angles, and pi is a ratio of a circumference of a circle to a diameter of the circle, wherein the circle is an imaginary circle with the reference point as a center of the circle." in combination with the other limitations of the claim.
Regarding claim 9, the prior art of record does not teach or suggest "wherein the plurality of chief ray angles are calculated using Equation 1: c6x^6 + c5x^5+c4x^4+c3x^3+c2x^2+c1x.... (1); where x represents a distance between a point of interest of the plurality of points of interest and the reference point, c6 is -0.2995, c5 is 3.083, c4 is -10.67, c3 is 13.44, c2 is -8.388, and c1 is 25.12" in combination with the other limitations of the claim.
Regarding claim 10, the prior art of record does not teach or suggest "calculating a plurality of chief ray angle shrinkages by substituting the plurality of chief ray angles into Equation 2, respectively: 2.930*tan(arcsin(sin(CRA*pi/180)/1.57755)); where CRA represents one of the plurality of chief ray angles, and pi is a ratio of a circumference of a circle to a diameter of the circle, wherein the circle is an imaginary circle with the reference point as a center of the circle." in combination with the other limitations of the claim.
Regarding claim 16, the prior art of record does not teach or suggest "wherein the plurality of chief ray angles are calculated using Equation 1: c6x^6 + c5x^5+c4x^4+c3x^3+c2x^2+c1x.... (1); where x represents a distance between a point of interest of the plurality of points of interest and the reference point, c6 is -0.2995, c5 is 3.083, c4 is -10.67, c3 is 13.44, c2 is -8.388, and c1 is 25.12" in combination with the other limitations of the claim.
Regarding claim 17, the prior art of record does not teach or suggest "calculating a plurality of chief ray angle shrinkages by substituting the plurality of chief ray angles into Equation 2, respectively: 2.930*tan(arcsin(sin(CRA*pi/180)/1.57755)); where CRA represents one of the plurality of chief ray angles, and pi is a ratio of a circumference of a circle to a diameter of the circle, wherein the circle is an imaginary circle with the reference point as a center of the circle." in combination with the other limitations of the claim.
Response to Arguments
Applicant's arguments filed on December 22, 2025 have been fully considered but are not persuasive for the reasons set forth below.
With respect to claim 1, Applicant argues that Jang's azimuthal angle is a slit-plane illumination descriptor rather than a mask-plane incidence angle, and that Jang does not identify a maximum chief ray angle. The Examiner disagrees. Jang [0033] teaches position-dependent angular variation of EUV light across the slit at the mask design, and Jang [0059-0066] calculates thirteen distinct angular values at specific slit positions that directly correspond to chief ray angles at points of interest on the mask design. The amended language "on the mask design" does not further distinguish because Jang's entire OPC analysis is performed in the context of mask design. Jang [0068]'s identification of regions with aberrations "largely different" from the center region corresponds to identifying the point of maximum chief ray angle. Applicant further argues that Word [0033] and [0041] do not teach the chief ray incidence angle limitation. Upon reconsideration, the Examiner withdraws reliance on Word [0033] and [0041] for that limitation and replaces those citations with Word [0003] and [0049]. Word [0003] explicitly teaches that in an EUV system the chief ray is off-axis by approximately 6 degrees at the mask plane, and that the system is non-telecentric at the mask plane, establishing that the chief ray arrives at each point on the mask design at a defined incidence angle. Word [0049] establishes a coordinate system for the mask plane with a horizontal axis H and a vertical axis V, defines the inclination angle of illumination measured from the mask plane normal, and teaches that layout features at different positions in the illuminated field are illuminated at different angles — establishing the concept of an incidence angle of a chief ray at each point of interest with respect to the vertical direction of the mask design plane. The rejection is maintained on this corrected basis.
With respect to Babcock, Babcock [Column 6 Lines 5-15] establishes a reference point through its test pattern layout, and Babcock [Column 12 Lines 5-15] identifies specific locations on the mask where optical problems occur relative to those reference positions, which constitutes setting a deteriorated distance. Applicant argues the Jang and Babcock combination is the result of hindsight because the two references operate on incompatible principles. The Examiner disagrees. Both references are directed to improving photolithography mask design accuracy — Jang by calculating position-dependent chief ray angles across the slit and Babcock by identifying reference points and deteriorated distances in a mask layout. These are complementary OPC techniques within the same field of art. A person of ordinary skill in the art would combine them to produce an improved OPC system with a reasonable expectation of success, and this combination does not alter the fundamental operation of either reference.
The rejections of claims 8 and 15 and their dependents are maintained for at least the reasons discussed above with respect to claim 1. With respect to claim 8 specifically, the concentric zone structure is additionally supported by Jang [0074-0075], which teaches dividing the slit into multiple regions where TCC calculations are performed for each region extending from the center, directly mapping to the claimed plurality of zones concentric with reference to the reference point.
Conclusion
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
Prosecution Insights