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 .
The response of the applicant has been read and given careful consideration. Rejection of the previous action not appearing below are withdrawn based upon the amendments and arguments of the applicant. Responses to the arguments are presented after the first rejection they are directed to.
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 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.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
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 9-10,14-16 and 20 are rejected under 35 U.S.C. 102(a)(1) as being fully anticipated by, in the alternative, under 35 U.S.C. 103 as obvious over Wu CN 1673867.
Wu CN 1673867 (machine translation attached) establishes that NILS represents a measure of the quality of the imaging and is preferably higher as this increases the process range. For 248 nm photolithography processes, the NILS must be more than 1.3 to 1.5 to result in a valid/desired photoresist pattern (page 2/lines 8-16). As shown in FIG. 5 A light shield layout 50 after exposure of the shadow intensity (Pogostemoncablin intensity) curve diagram. 52b seen in a linear pattern is horizontal position origin after adding auxiliary patterns 54, 56, 58, 60 to improve the line pattern 52b to the two linear patterns 52a, the shadow intensity curve slope between 52c. to improve the shadow contrast (Pogostemoncablin image contrast), can improve the pattern by lithography on the photoresist layer of the resolution, the NILS value is improved from 1.15 to 2.5, and avoids the problem of the traditional forbidden pitch.
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This clearly establishes that adding assist features increases the NILS values (5/16-21). The integrated circuit layout design data of mask layout is processed at the factory to transfer the design of the mask layout pattern on each photomask, by a photolithographic process on the photo mask pattern transfer in a certain ratio (transfer) to the photoresist layer on surface of semiconductor chip (1/12-15)
Wu CN 1673867 teaches a 1.3 to 1.5 as the lower boundary for the NILS, which is a normalized image log slope and the addition of assist features to mask pattern, but does exemplify the production of a photomask as part of that process.
The examiner holds that one skilled in the art reading the reference would immediately envision extending the process to include production of the mask using the patterns which have been evaluated for their NILS and had assist (OPC) features added , thereby anticipating the claimed invention. The examiner points out that the layout information/pattern with the assist features does not have any other utility.
If this position is not upheld, the examiner holds that it would have been obvious to one skilled in the art to extend the process including the determination of the NILS and the addition of the assist (OPC) features to include forming a photomask according the layout so that the pattern can be used to form semiconductor devices as discussed at (1/12-15) with a reasonable expectation of forming a useful photomask. With respect to claims 16 and 20, the NILS is the product of the ILS and the dimensions of the (printable) features, so the calculation of the NILS effectively sorts the pattern on the basis of size.
In the response of 1/20/2026, the applicant argues that Wu et al. uses NILS, no the ILS. The examiner points out that the normalized image log slope (NILS) is normalized to account for the size of the features and is a type of ILS. The addition of the assist features inherently reduces the dosage of the exposure as these light shielding features block a portion of the light/radiation used in the exposure. They also increase the contrast of the image. The applicant is invited to explain how changes in the ILS are not reflected in the normalized ILS (NILS). The rejection stands.
The applicant argues that the limitation of the dependent claims are not specifically addressed and therefore any subsequent action should be non-final. The examiner has pointed to specific examples and teachings in the references which establish the anticipation (on in the case of later rejections obviousness) of embodiments bounded by the claims to one of ordinary skill in the art and pointed out the portions of the references which describe the addition of features (assist features, serifs, hammers/hammerheads) which by their addition block light and reduce the exposure. The examiner has pointed out that serifs and hammers/hammerheads are widening of the patterns, while assist features are separate, light blocking features and the effect of these in the NILS. The examiner has met the burden of examination.
Claims 1,2,4-12 and 14-20 are rejected under 35 U.S.C. 103 as obvious over Nonami et al. WO 2012039078
Nonami et al. WO 2012039078 (machine translation attached) teaches setting the NILS to 1.3 or more for ArF exposures. As shown in FIG. 4, outside the range where the width of the light shielding portion is extremely small, it is necessary to reduce the width of the light shielding portion in order to obtain the effect of increasing the DOF. Therefore, as a specific example, the width of the light-shielding portion is 0.05 × λ / NA (7 nm according to the example described as the premise) or more and 1.13 × λ / NA (161 nm according to the same example) or less. Then, the DOF is improved by 10 or more compared to the binary mask. Furthermore, when the width of the light-shielding portion is set to 0.12 × λ / NA (17 nm according to the same example) or more and 0.63 × λ / NA (90 nm according to the same example) or less, 20% or more is achieved. The DOF can be improved. In addition, similarly, it is possible to obtain the range of the width B1 of the light-shielding portion that is desirable for improving the DOF by a desired amount from FIG.4.
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When the width of the light shielding pattern (at the edge) is reduced the NILS is reduced. Figure 5 shows the relationship between width B1 of the light shielding portion (figure 1b, and 1c) and the NILS for isolated features.
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In the fine process, the NILS value is preferably 1.3 or more. From FIG. 5, it can be seen that the width B1 of the light shielding portion needs to be 0.13 × λ / NA (18 nm in the case of the premise) or more. In addition, the width B1 of the light shielding portion necessary for obtaining a desired NILS can be obtained from FIG.
Considering together the points based on DOF and NILS as described above, it can be seen that the maximum value is determined by DOF and the minimum value is determined by NILS for the width B1 of the light shielding portion.
As a specific example, the distance between the mask pattern having a width L2 larger than 0.7 × λ / NA and the adjacent mask pattern (space dimension S1) is smaller than 0.5 × λ / NA. Consider a photomask (photomask 40 in FIGS. 1B and 1C). At this time, the semi-light-shielding portions 13a and 13b are arranged in the mask patterns 14a and 14b having the width L2, and the light-shielding portions having a width of 0.13 × λ / NA or more and 1.13 × λ / NA or less around the periphery. 12a and 12b are arranged. As a result, sufficient NILS can be secured and the DOF of the isolated space can be improved by 10% or more. Similarly, when the width of the light shielding portion is 0.13 × λ / NA or more and 0.63 × λ / NA or less, sufficient NILS can be ensured and the DOF of the isolated space can be improved by 20 or more [0078-0086].
FIG. 12 shows still another exemplary photomask 44 for forming the pattern of FIG. The photomask 44 is the same as the photomask 40 in FIG. 1B in that the semi-light-shielding portions 13a and 13b are arranged at the peripheral portions of the mask patterns 14a and 14b. However, regarding the light shielding portions 12a and 12b surrounding the semi-light shielding portions 13a and 13b, the width B2 of the planar convex corner portion 71 is larger than the width B3 of the concave corner portion 72. This is a shape considering optical proximity effect correction (OPC: optical proximity correction). By using such a mask pattern, the shape of the pattern after transfer can be improved (rectangularity improved) in both the convex corner portion 71 and the concave corner portion 72. In the dense mask pattern 15, the widths at both ends are wide for the same reason [0109].
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For this purpose, the width of the auxiliary pattern 31 is set to a dimension smaller than the main pattern 30 and less than the resolution limit. In general, the auxiliary pattern is arranged in a rule base with respect to the main pattern. After the auxiliary pattern is arranged, model-based OPC (Optical / Proximity / Correction) is usually performed on the main pattern [0010]. a photomask is used in a reduction projection type exposure machine, the reduction magnification must be considered when discussing the pattern dimensions on the mask. However, in the following embodiments, in order to avoid confusion, when the pattern dimensions on the mask are described in correspondence with a desired pattern to be formed (for example, a resist pattern), the dimensions are reduced by a reduction ratio unless otherwise specified. The converted value is used. As a specific example, when a resist pattern having a width of 63 nm is formed by a mask pattern having a width of M × 63 nm in a 1 / M reduction projection system, both the mask pattern width and the resist pattern width are expressed as 63 nm. [0057]
Nonami et al. WO 2012039078 teaches a lower boundary for the NILS of 1.3, which is a normalized image log slope and the addition of assist features to mask pattern, but does exemplify the production of a photomask as part of that process.
It would have been obvious to one skilled in the art to extend the process including the determination of the NILS and the adjustment of the widths/sizes of the printed features ss in figure 12, where the addition of the serifs increases the size of the parents to be printed and reduces the ILS, followed by the addition of auxiliary patterns as disclosed at [0010], which increases the NILS and to use the resulting layout to form a physical mask suitable for use in the exposure processes disclosed at [0057] with a reasonable expectation of forming a suitable photomask. With respect to claims 16-20, the NILS is the product of the ILS and the dimensions of the (printable) features, so the calculation of the NILS effectively sorts the pattern on the basis of size. The dependency of the NILS on the pattern is clear form figure 5.
In the response of 1/20/2026, the applicant argues with respect to claims 1,9 and 16, that the references does not teach reducing the exposure dosage. The examiner points out that the addition of serifs increases the size of the features which block light, so the exposure is reduced. And the reference is clearly mindful of the NILS as auxiliary features which also reduce the exposure by blocking light and increasing the NILS is taught. The normalization of the ILS to account for the feature sizes does not make it not a type of ILS bounded by the claims. The rejection stands.
Claims 1,2,4-11 and 14-20 are rejected under 35 U.S.C. 102(a)(1) as being fully anticipated by Kim 20100162195.
Kim 20100162195 describes with respect to the flow chart of figure 2, a method of forming a final exposure mask which is useful for detecting mask error enhancing functions (MEEF). This includes inputting a mask pattern layout (S100), performing an optical proximity correction on the layout using simulation modeling and performing a calibration. The calibration involves adding or removing patterns which are below (lower than) the mask resolution. This might include adding serifs, hammer patterns or scattering bars, which are below the resolution of the exposure. The evaluation of the optical proximity correction is based upon the normalized image log slope (NILS). The NILS is determined by multiplying the image log slope (ILS) by the critical dimension factor of the pattern. The specification of the MILS includes determining the minimum NILS as calculated using formula 2. This identifies weak points in the pattern which would cause a defect on the wafer. The NILS form the patterns is below the NILS specification, the pattern returns to the step S100 and is subjected to optical proximity correction. This process is repeated until the NILS is within the specification and then the mask is written [0029-0050].
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The discussion of Kim 20100162195 clearly describes two categories of pattern sizes. Printable patterns which are above the resolution limit of the exposure system and sub-resolution patterns, which do not print out. The addition and removal of the sub-resolution features such as scattering bars, hammers/hammerheads and serifs which will affect the image log slope (ILS) of the printable features is clearly described. The validation of the pattern is performed on the basis of the NILS data and the mask manufactured.
The NILS calculation is the product of the ILS and the pattern dimension and so represents a sorting of the patterns on the basis of size. The addition of serifs and hammers increases the size of the features and is held to decrease the ILS of the patterns. The calculation on the basis of critical dimension (pattern size) is disclosed, which addresses the limitations of claims 2,12 and 19.
In the response of 1/20/2026, the applicant argues that Kim et al. does not teach the reduction in the exposure dose. This arguments fails to appreciate that adding serifs, and hammers/hammerheads increases the size of the features where they are added and this increase in size inherently reduces the exposure dosage as more light is blocked by the larger features. The rejection stands.
Claims 1,2,4-12 and 14-20 are rejected under 35 U.S.C. 103 as being unpatentable over Kim 20100162195, in view of Tian et al. 20120052418 and Park KR 20050080819.
Tian et al. 20120052418 in figure 1 teaches the fractional shot noise can be obtained by plotting the line width roughness (LWR) vs the inverse of the image log slope (1/ILS)
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Figure 9 show the effect of source mask optimization with an without constraints on the ILS, with the use of constrained ILS leading to lower line edge roughness (LER).[0031,0134].
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Park KR 20050080819 (machine translation attached) A photomask including a scattering bar formed by etching a transparent substrate is disclosed. The photo mask according to an embodiment of the present invention is formed on a transparent substrate and a transparent substrate through which incident light passes, and is formed by etching a main pattern and a transparent substrate transferred to a photosensitive material film by incident light with a predetermined width and depth And a scattering bar that is not transferred to the photosensitive material film by incident light. The width and depth of the scattering bar are adjusted to a size that improves the generalized image log slope (NILS) of the aerial image of the incident light that has passed through the photo mask, in which case the scattering bar is reduced by the relaxed offset effect. It is not transferred to the wafer (abstract).
Kim 20100162195 does not provide a detailed description of the widened of the features and effect of the addition of scattering bars/assist features.
It would have been obvious to one skilled in the art to modify the teachings of Kim 20100162195 by forming widened features on the printable features as illustrated in Tian et al. 20120052418 in a constrained ILS optimization process which results in a lower ILS for those features, followed by the addition of assist features as taught by Park KR 20050080819 to increase improve the pattern transfer, which ILS and NILS are a measure of.
In the response of 1/20/2026, the applicant argues that the references do not teach the adjustment of the size of the features to decrease the exposure dose. This arguments fails to appreciate that increasing the size of the features reduces the exposure light as the increased feature sizes result in more light/radiation being blocked. The addition of the assist features also reduces the amount of light passing through the mask, while increasing the ILS/NILS.
Claims 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Kim 20100162195, in view of Tian et al. 20120052418 and Park KR 20050080819, further in view of Naulleau, “Correlation method for the measure f mask-induced line-edge roughness in extreme ultraviolet lithography”, Appl. Opt. Vol. 48(18) pp 3302-3307 (06/2009) and Hsu et al. 20200249578.
Naulleau, “Correlation method for the measure f mask-induced line-edge roughness in extreme ultraviolet lithography”, Appl. Opt. Vol. 48(18) pp 3302-3307 (06/2009) establishes for EUV exposure systems, image log slopes with annular illumination systems of 85 μm−1 are known (see table 2, page 3307, left column)
Hsu et al. 20200249578 in figure 6B illustrates the effect of anchor mask bias (650, nm) versus NILS (652).
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The combination of Kim 20100162195 Tian et al. 20120052418 and Park KR 20050080819 does not teach ISL values within the recited range.
In addition to the basis above, the examiner holds that it would have been obvious to extend the processes rendered obvious by the combination of Kim 20100162195 Tian et al. 20120052418 and Park KR 20050080819 to EUV masks using annular exposure with a reasonable expectation of success noting that Naulleau, “Correlation method for the measure f mask-induced line-edge roughness in extreme ultraviolet lithography”, Appl. Opt. Vol. 48(18) pp 3302-3307 (06/2009) and Hsu et al. 20200249578 establish the known use of ILS and NILS as EUV mask/exposure system evaluation metrics.
In response of to the arguments of 1/20/2026, the examiner relies upon the response above as no further arguments were advanced.
Claims 1,2,4-12 and 14-20 are rejected under 35 U.S.C. 103 as being unpatentable over Kim 20100162195, in view of Tian et al. 20120052418 and Park KR 20050080819, further in view of He et al. 20160291458 and/or Tseng et al. 20170052455.
He et al. 20160291458 teaches that the higher the image log slope, the lower the sensitivity of critical dimension variation (Δx) to the exposure energy changes (Δd), which will achieve better imaging stability, and greater process window [0039]. Therefore, on one hand, when optimizing the target pattern, step S03 is performed at first to simulate the target pattern and calculate the image log slope (ILS) for each fragment. In this step, preferably, the target pattern is simulated by using a model which is same as an OPC model used in the subsequent optical proximity correction process. The target pattern is simulated with small variation in the exposure energy (ΔI) respectively to obtain the edge aberration (Δx) of the simulated target pattern, whereby the image log slope of each fragment is obtained [0040].
Tseng et al. 20170052455 teaches a method to adjust line-width roughness (LWR) in a lithographic apparatus, the method including receiving a value of LWR and/or image log slope (ILS) for each feature of a plurality of different features of a pattern to be imaged, using a patterning device, onto a substrate in a lithographic process, and evaluating a cost function including a lithographic parameter and the values of LWR and/or ILS to determine a value of the lithographic parameter that (i) reduces a bias between the LWR and/or ILS of the different features, or (ii) reduces a difference in the LWR and/or ILS of the different features between different lithographic apparatuses, or (iii) reduces a difference in the LWR and/or ILS of the different features between different patterning devices, or (iv) any combination selected from (i)-(iii). (abstract). For a particular image, if a line is not “sharp”, ILS will have a relatively smaller value since the intensity across the line edge does not change “rapidly”. In such instances, line-width of a particular line may vary from its nominal value. The variability in line-width is measured by line-width roughness (LWR), i.e., LWR is a measure of a feature line width from a nominal linewidth. Thus, it can be seen that as LWR decreases, ILS increases and vice versa (LWR and ILS may not always vary in proportion to each other). The typical imaging behavior of dense features of a patterning device pattern is the generally insensitive CD response through focus, as shown in FIG. 11. However, as shown in FIG. 11, the ILS may see significant change over the same focus range. Further, small ILS will cause large LWR along lines. So to minimize LWR, ILS should be maximized [0094].
The combination of Kim 20100162195 Tian et al. 20120052418 and Park KR 20050080819 does not teach using of line roughness or variation in the exposure dosage to in the evaluation of the NILS or ILS.
It would have been obvious to one skilled in the art to modify the processes rendered obvious by the combination of Kim 20100162195 Tian et al. 20120052418 and Park KR 20050080819 by using known parameters for evaluation ILS/NILS such as line edge roughness and/or variation in the dosage with a reasonable expectation of success based upon their prior use in the art as evidenced in He et al. 20160291458 and/or Tseng et al. 20170052455.
In response of to the arguments of 1/20/2026, the examiner relies upon the response above as no further arguments were advanced.
THIS ACTION IS MADE FINAL. 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 Martin J Angebranndt whose telephone number is (571)272-1378. The examiner can normally be reached 7-3:30 pm EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Mark F Huff can be reached at 571-272-1385. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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MARTIN J. ANGEBRANNDT
Primary Examiner
Art Unit 1737
/MARTIN J ANGEBRANNDT/Primary Examiner, Art Unit 1737 March 4, 2026