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 .
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 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Philips et al. 20230194997, in view of Fujiwara 20020016015, Laidig et al. 20020028393 and Garza et al. 5804340.
Philips et al. 20230194997 teaches mating patterns which span reticle boundaries to facilitate die to die stitching. Figure 3A (detail reproduced below) shows mating patterns in reticle 1 (R1,108) and reticle 2 (R2,109)which are based upon the overlap of the stair step ends [0007,0040,0044-0049].
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Figure 3F shows overlap (352) when misaligned [0057].
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Other complementary features are shown in figures 4A and 5A
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Notably, creating features using lithography involves coating a wafer with a photosensitive resist, which is typically sensitive to light of a certain wavelength. The light of this wavelength is then shone through a mask that contains the desired pattern to be transferred to the wafer. Herein, patterns, regions, features and the like are discussed with respect to reticle mask patterns and resultant patterns on the photoresist interchangeably. It is noted that the pattern at the resist level is typically reduced (e.g., by 4×) from the reticle mask level and is invariably an imperfect reproduction. Herein, the discussed patterns, regions, or features may be at the reticle level (i.e., in the reticle mask) or at the resist level (e.g., either pre- or post-development). The region on the wafer that is exposed to the light generates photoacids that break down the resist polymer making it soluble in a developer solution. In reticle stitching contexts, a feature such as a line feature is generated by two different masks (or different regions of the same mask) exposed sequentially such that a portion of the line feature from the first exposure and a portion of the line feature from the second exposure are adjoined at the stitch. As used herein, the term adjoin indicates two features, portions, or regions are in contact with one another [0035]. Exposure 217 continues from reticle 203 through optics 208 to expose a photoresist layer 202 on or over a substrate 201 (e.g., a substrate wafer). As discussed, the resultant exposure generates photoacids that break down the resist polymer of photoresist layer 202, rendering it soluble in a developer solution. As discussed, pattern 206 or 216 is transferred from reticle 203 to photoresist layer 202. The pattern features, regions, etc. discussed herein are applicable to either or both of pattern 206 or 216 of reticle 203 and the resultant pattern of photoresist layer 202. Although illustrated with respect to the pattern being in transparent substrate 204 for use in positive photoresist applications, the pattern may be deployed in negative photoresist contexts [0043]
Fujiwara 20020016015 in figure 5a illustrates the overlap of the stitching element and the widening of the resist feature (transferred image) is illustrated in figure 5d, which is considered a small variation. When the parts are exactly matched as in figure 5b, the pattern transferred to the resist is the desired 100 nm. When the stitching elements are slightly separated as in figure 5c, the transferred pattern is slightly narrower, which is considered a small variation [0048].
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Figure 6 illustrates the rounding /blunting of mating ends and that this can result in mask-fabrication errors (the dashed line shows the desired/mask pattern, while the solid lines show the transferred image). Mating ends with this rounding to the required interconnection accuracy is difficult to impossible [0051].
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The modifications to the patterns of figure 5 are illustrated in figure 7, 11. And 14. [0052-0060,0065].
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The design modification follows the flow chart in figure 8 [0024,0053-0055]. Whenever a subfield of the mask 20 is being illuminated by the illumination beam IB, the resulting patterned beam PB is reduced (demagnified) by the projection lenses 22, 23 and deflected as required to focus an image of the subfield at a specified location on the wafer 24. The surface of the wafer 24, on which an appropriate conductive film or insulating film has been formed, is coated with a suitable resist. In areas of the resist subjected to a patterned-beam dose exceeding a specified threshold, the resist can be made more durable than unexposed resist and caused to remain (in the case of a negative resist) on the wafer after resist development. Thus, the pattern defined by the mask 20 is transferred to the resist on the wafer 24 [0042].
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Laidig et al. 20020028393 discloses the addition of serifs at vertices, where the size of the serifs are chosen independently to low the mask pattern to be reproduced faithfully. Figure 1 illustrates a negative serif (NSW, 13) in an interior corner and a positive serif (PSW, 12) [0050] Figure 5 illustrates (positive) serifs (61,62,66,67,73,76) at the corners and a hammer head (serifs 69/70 touching)
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Garza et al. 5804340 illustrates a mask design pattern in figure 1 and the resulting chrome pattern with corner rounding shown in figure 2.
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Figure 5A illustrates the shape of the correct photomask with (negative/in) serif (212) and (positive/out) serifs (202,204,206,208,210) to prevent/reduce rounding at the corners (4/.39-51)
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Philips et al. 20230194997 teaches the matching/mating on two different reticles, but does not teaches the mask patterns having a combination of matching/mating surfaces/edges and areas where the mask patterns overlap, rather than match/mate.
With respect to claims 1-6 and 8-10, it would have been obvious to one skilled in the art to modify the mask sets of Philips et al. 20230194997 with the mating features illustrated in figures 3A, 4A or 5A by adding positive serifs on the outer corners and negative serifs on the inner corners as taught by Laidig et al. 20020028393 and Garza et al. 5804340 so that the projected patterns are more accurate, noting that correction to mating/complementary stitching patterns to account for rounding of the patterns in known ion the art as evidenced by Fujiwara 20020016015. The use of either polarity of mask is illustrated in figure 3A of Philips et al. 20230194997 and is considered an obvious modification.
With respect to claims 1-7 and 9-10, it would have been obvious to one skilled in the art to modify the mask sets of Philips et al. 20230194997 with the mating and complementary features illustrated in figure 3A by adding positive serifs on the outer corners and negative serifs on the inner corners as taught by Laidig et al. 20020028393 and Garza et al. 5804340 so that the projected patterns are more accurate, noting that correction to mating/complementary stitching patterns to account for rounding of the patterns in known ion the art as evidenced by Fujiwara 20020016015. The use of either polarity of mask is illustrated in figure 3A of Philips et al. 20230194997 and is considered an obvious modification. As the patterns are made to mate, the first pattern has inner corners (where negative serifs are added) where the second pattern has outer corners (where positive serifs are added) and first pattern has outer corners (where positive serifs are added) where the second pattern has inner corners (where negative serifs are added). The positive serifs are protrusion and negative serifs are the corresponding recesses.
With respect to claims 1-6,8-10 and 20, it would have been obvious to one skilled in the art to modify the mask sets of Philips et al. 20230194997 with the mating features illustrated in figures 3A, 4A or 5A by adding positive serifs on the outer corners and negative serifs on the inner corners as taught by Laidig et al. 20020028393 and Garza et al. 5804340 so that the projected patterns are more accurate, noting that correction to mating/complementary stitching patterns to account for rounding of the patterns in known ion the art as evidenced by Fujiwara 20020016015 and to expose a resist with each pattern and develop the composite pattern in the resist as taught in Philips et al. 20230194997 at [0043,0035], noting the teachings of Fujiwara 20020016015 at [0042]. The use of either polarity of mask is illustrated in figure 3A of Philips et al. 20230194997 and is considered an obvious modification. As the patterns are made to mate, the first pattern has inner corners (where negative serifs are added) where the second pattern has outer corners (where positive serifs are added) and first pattern has outer corners (where positive serifs are added) where the second pattern has inner corners (where negative serifs are added). The positive serifs are protrusion and negative serifs are the corresponding recesses.
With respect to claims 1-7, 9-10 and 20, it would have been obvious to one skilled in the art to modify the mask sets of Philips et al. 20230194997 with the mating and complementary features illustrated in figure 3A by adding positive serifs on the outer corners and negative serifs on the inner corners as taught by Laidig et al. 20020028393 and Garza et al. 5804340 so that the projected patterns are more accurate, noting that correction to mating/complementary stitching patterns to account for rounding of the patterns in known ion the art as evidenced by Fujiwara 20020016015. and to expose a resist with each pattern and develop the composite pattern in the resist as taught in Philips et al. 20230194997 at [0043,0035], noting the teachings of Fujiwara 20020016015 at [0042]. The use of either polarity of mask is illustrated in figure 3A of Philips et al. 20230194997 and is considered an obvious modification. As the patterns are made to mate, the first pattern has inner corners (where negative serifs are added) where the second pattern has outer corners (where positive serifs are added) and first pattern has outer corners (where positive serifs are added) where the second pattern has inner corners (where negative serifs are added). The positive serifs are protrusion and negative serifs are the corresponding recesses.
With respect to claims 1-6,8-15 and 17-19, it would have been obvious to one skilled in the art to modify the mask sets of Philips et al. 20230194997 with the mating features illustrated in figures 3A, 4A or 5A by forming a desired/target pattern as taught in Fujiwara 20020016015 and Garza et al. 5804340 and adding positive serifs on the outer corners and negative serifs on the inner corners as taught by Laidig et al. 20020028393 and Garza et al. 5804340 so that the projected patterns are more accurate, noting that correction to mating/complementary stitching patterns to account for rounding of the patterns in known ion the art as evidenced by Fujiwara 20020016015. The use of either polarity of mask is illustrated in figure 3A of Philips et al. 20230194997 and is considered an obvious modification. As the patterns are made to mate, the first pattern has inner corners (where negative serifs are added) where the second pattern has outer corners (where positive serifs are added) and first pattern has outer corners (where positive serifs are added) where the second pattern has inner corners (where negative serifs are added). The positive serifs are protrusion and negative serifs are the corresponding recesses.
With respect to claims 1-6,8-16 and 18-19, it would have been obvious to one skilled in the art to modify the mask sets of Philips et al. 20230194997 with the mating and complementary features illustrated in figure 3A by forming a desired/target pattern as taught in Fujiwara 20020016015 and Garza et al. 5804340 and adding positive serifs on the outer corners and negative serifs on the inner corners as taught by Laidig et al. 20020028393 and Garza et al. 5804340 so that the projected patterns are more accurate, noting that correction to mating/complementary stitching patterns to account for rounding of the patterns in known ion the art as evidenced by Fujiwara 20020016015. The use of either polarity of mask is illustrated in figure 3A of Philips et al. 20230194997 and is considered an obvious modification. As the patterns are made to mate, the first pattern has inner corners (where negative serifs are added) where the second pattern has outer corners (where positive serifs are added) and first pattern has outer corners (where positive serifs are added) where the second pattern has inner corners (where negative serifs are added). The positive serifs are protrusion and negative serifs are the corresponding recesses.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Garza et al. 5972541 illustrates the use of positive and negative serifs in figure 7C and 8 (col/ 14/lines 16-22,36-43)
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Wampler 5663893 illustrates in figure 1B, the use of positive serifs (11) and negative serifs (12) .
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Capodieci 6044007 establishes the rounding of inner and outer corners of features in known in the art in figures 1 and 2. An exemplary prior art reticle is illustrated in FIG. 1. Prior art FIG. 1 includes a reticle 10 corresponding to a desired integrated circuit pattern 12. For simplicity, the pattern 12 consists of only two design features. A clear reticle glass 14 allows radiation to project onto a resist covered silicon wafer. The chrome regions 16 and 18 on the reticle 10 block radiation to generate an image on the wafer corresponding to the desired integrated circuit design features. As light passes through the reticle 10, it is diffracted and scattered by the edges of the chrome 16 and 18. This causes the projected image to exhibit some rounding and other optical distortion. While such effects pose relatively little difficulty in layouts with large features (e.g., features with critical dimensions greater than one micron), they cannot be ignored in present day layouts where critical dimensions are about 0.25 micron or smaller. The problem highlighted above becomes more pronounced in integrated circuit designs having feature sizes below the wavelength of the radiation used in the photolithographic process.
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( Prior art FIG. 2 illustrates the impact of the diffraction and scattering caused by the radiation passing through the reticle 10 and onto a section of a silicon substrate 20. As illustrated, the illumination pattern on the substrate 20 contains an illuminated region 22 and two dark regions 24 and 26 corresponding to the chrome regions 16 and 18 on the reticle 10. The illuminated pattern 22 exhibits considerable distortion, with the dark regions 24 and 26 having their corners 28 rounded. Unfortunately, any distorted illumination pattern propagates through the developed resist pattern and negatively impacts the integrated circuit features such as polysilicon gate regions, vias in dielectrics, etc. As a result, the integrated circuit performance is degraded. To remedy this problem, a reticle correction technique known as optical proximity correction (OPC) has been developed. OPC involves the adding of dark regions to and/or the subtracting of dark regions from portions of a reticle to overcome the distorting effects of diffraction and scattering. Typically, OPC is performed on a digital representation of a desired integrated circuit pattern. This digital representation is often referred to as the mask layout data and is used by the reticle manufacturer to generate the reticle. First, the mask layout data is evaluated with software to identify regions where optical distortion will result. Then the OPC is applied to compensate for the distortion. The resulting pattern is ultimately transferred to the reticle glass.
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The pattern in figure 4 is more accurate than the pattern illustrated in figure 2.
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 11, 2026