DETAILED ACTION
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 4, 6, 10, 11, 13-16, and 18-22 are rejected under 35 U.S.C. 103 as being unpatentable over Buurman et al. [US 2013/0022901] in view of Patra et al. [US 2015/0085271].
For claims 1 and 14, Buurman teaches a system (see Figs. 2 and 6 and [0070]-[0076]) comprising:
at least a first sensor (264A) of a lithographic apparatus, each configured to measure a value of property related to an elongate illumination region provided for imaging a substrate by the lithographic apparatus and located at a first end of the illumination region (intensity sensors, see [0074] and Fig. 6); and
a processor (SOCTRL 242 and module 340) and configured to:
determine, based on a ratio of the measured values of the property as measured by one of sensors in relation to another (measured asymmetry profile 334 provided as a comparison between measured intensities, see [0074]), a drift of the illumination region (measured asymmetry profile 334 is the determined systematic drift and the asymmetry signal is fed back, see [0074]-[0077]);
determine, based on the drift of the illumination region, a drift in an attribute related to the illumination upstream of the illumination region measured by at least two sensors (asymmetry in the intensity profile used to determine irregularities of the source, see [0061], [0064], [0070]-[0077]), and
determine, based on the drift in the attribute, a drift correction to be applied to the attribute to compensate for the drift in the attribute (non-uniformity correction to reduce asymmetry to zero, see [0072]-[0077]), and
initiate a signal to a device to apply the drift correction to the attribute to compensate for the drift in the attribute (signal ASX provided to source controller to optimize symmetry, see [0073], or other mechanisms, such as the UNICOM, see [0076]); and
a single second sensor (264B) of the lithographic apparatus located at a second opposite end of the illumination region, the second sensor configured to measure an intensity of the illumination region (intensity sensors, see [0074] and Fig. 6).
Buurman also teaches that a plurality of sensors may be provided around the slit (see [0073]-[0075]) and that other corrections can be applied to correct for deviations of the of the droplet that influence asymmetry in the scanning direction (see [0077]).
Buurman fails to teach at least two first sensors of a lithographic apparatus, each configured to measure a value of property related to an elongate illumination region provided for imaging a substrate by the lithographic apparatus and each located at a first end of the illumination region are used in the drift calculation and correction in scanning direction, and a processor configured to determine, based on the measured values of the property as measured by one of the first sensors in relation to another of the first sensors, a drift of a central portion of the illumination region with respect to a reference position.
Patra teaches a system comprising: at least two first sensors (68a and 68b, see Figs. 3 and 4) of a lithographic apparatus (see Fig. 1), each configured to measure a value of property (intensity, see [0058]-[0059]) related to an elongate illumination region (60) provided for imaging a substrate by the lithographic apparatus and each located at a first end of the illumination region (on one of the sides of the slit 60);
a processor (control device 54, see [0052]) configured to: determine, based on the measured values of the property as measured by one of the first sensors in relation to another of the first sensors, a drift of a central portion of the illumination region with respect to a reference position (if slit 60 is displaced upward or downward in the scanning y direction, the corresponding sensor element 68a registers an increased intensity and the central sensor element 68b, representing the intended central reference positional state, then partly protrudes out of the area of the illumination slit 60 and therefore registers a reduced intensity and the positional change is then measured, see [0058]), determine, based on the drift of the illumination region, a drift in an attribute related to the illumination upstream of the illumination region measured by the at least two first sensors (measured intensity along scanning direction 62 related to the dose change associated with instabilities of source 20, see [0052] and [0055]-[0059]), determine, based on the drift in the attribute, a drift correction to be applied to the attribute to compensate for the drift in the attribute (modifying the intensity of the exposure radiation 22 emitted by the radiation source 20, see [0052], [0062], and [0070]), and initiate a signal to a device to apply the drift correction to the attribute to compensate for the drift in the attribute (control device 54 converts the measurement signal 51 into control signals 56 to adjust the source 20, see [0052], [0062], and [0070]); and
a single second sensor (second of sensors 68b or 68a on the other side of slit 60) of the lithographic apparatus located at a second opposite end of the illumination region, wherein the second sensor configured to measure an intensity of the illumination region (intensity, see [0058]-[0059]).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide the sensor arrangement and control as taught by Patra in the system using a ratio to quantify intensity difference as taught by Buurman in order to determine and correct for drift along the scanning direction and indicate the direction and extent of the nonuniformity so that asymmetry can be more accurately corrected.
For claim 20, Buurman teaches a non-transitory computer readable medium having instructions therein, the instructions, when executed by a computer system (see [0078]), configured to cause the computer system at least:
receive, from each of at least two sensors adjacent and elongate illumination region provided for imaging a substrate, a measurement of value of a property related to the illumination region provided for imaging a substrate (two or more sensors 264 provide measurement to the comparison module 340, se Fig. 6);
determine, based on a ratio of the measured values (measured asymmetry profile 334 along the central portion of slit 330, see [0074]), a drift of the illumination region (measured asymmetry profile 334 is the determined systematic drift and asymmetry signal is fed back for control, see [0074]-[0077]); and
determine, based on the drift of the illumination region, a drift correction to be applied to an attribute related to the illumination to compensate for the drift (non-uniformity correction to reduce asymmetry to zero, see [0072]-[0077]);
initiate a signal to a device to apply the drift correction to the attribute to compensate for the drift in the attribute (signal ASX provided to source controller to optimize symmetry, see [0073], or other mechanisms, such as the UNICOM, see [0076]); and
receive, via a single second sensor (264B) located at a second opposite end of the illumination region, measurement of an intensity of the illumination region (intensity sensors, see [0074] and Fig. 6).
Buurman also teaches that a plurality of sensors may be provided around the slit (see [0073]-[0075]) and that other corrections can be applied to correct for deviations of the of the droplet that influence asymmetry in the scanning direction (see [0077]).
Buurman fails to teach at receive, from each of at least two first sensors each located at a first end of an elongate illumination region provided for imaging a substrate, a measurement of value of a property related to the illumination region and determine a drift of a central portion of the illumination region with respect to a reference position.
Patra teaches receiving, from each of at least two first sensors (68a and 68b at one side of slit 60, see Figs. 3 and 4) each located at a first end of an elongate illumination region provided for imaging a substrate, a measurement of value of a property related to the illumination region (positional changes measured by the measuring device 50 are transmitted, in the form of a measurement signal 51, to a control device 54, see [0052]);
determine a drift of a central portion of the illumination region with respect to a reference position (if slit 60 is displaced upward or downward in the scanning y direction, the corresponding sensor element 68a registers an increased intensity and the central sensor element 68b, representing the intended central reference positional state, then partly protrudes out of the area of the illumination slit 60 and therefore registers a reduced intensity and the positional change is then measured, see [0058]); determine, based on the drift of the illumination region, a drift correction to be applied to an attribute related to the illumination to compensate for the drift (modifying the intensity of the exposure radiation 22 emitted by the radiation source 20, see [0052], [0062], and [0070]); initiate a signal to a device to apply the drift correction to the attribute to compensate for the drift in the attribute (control device 54 converts the measurement signal 51 into control signals 56 to adjust the source 20, see [0052], [0062], and [0070]); and receive, via a single second sensor (second of sensors 68b or 68a on the other side of slit 60) located at a second opposite end of the illumination region, measurement of an intensity of the illumination region (see [0057]-[0059]).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide the sensor arrangement and control as taught by Patra in the system using a ratio to quantify intensity difference as taught by Buurman in order to determine and correct for drift along the scanning direction and indicate the direction and extent of the nonuniformity so that asymmetry can be more accurately corrected.
For claim 4, Buurman teaches the drift in the attribute is caused by illumination optics collector contamination and/or an amount of power of an illumination source (see [0072]).
For claims 6 and 15, Buurman teaches the drift in the attribute is determined by conversion, based on a correlation between the drift of the illumination region and the drift in the attribute, the drift of the illumination region to the drift in the attribute (adjusting source errors by extrapolating source position using asymmetry profile to correct dose non-uniformity, see [0055]-[0056], [0061], [0063], [0072], and [0076]-[0077]).
For claims 10 and 18, in the combination, Patra teaches the measured property value are illumination intensity values measured by each of the at least two first sensors (see [0057]-[0059]).
For claims 11 and 19, Buurman teaches the illumination region is an illumination slit (330, see Fig. 6).
For claims 13, 16, and 22, in the combination, Patra teaches the reference position is an illumination slit position measured at a start of an imaging of a substrate in a lot or the reference position is at a central portion of an illumination slit (any deviation from the central sensor 68b results in a reduction in intensity measurement in the central sensor 68b and an increase of intensity on the edge sensor 68a that is used to determine the extent of positional change of the illumination slit 60 from an intended positional state, see [0058]).
For claim 21, in the combination, Patra teaches the attribute is dose, the drift in the attribute is a dose drift with respect to a nominal dose, and the drift correction is a dose drift correction and/or the attribute is a pupil, the drift in the attribute is a pupil drift with respect to a reference pupil, and the drift correction is a pupil drift correction (adjustment relative the nominal dose D0, see Figs. 7(a)-7(d)).
Claims 2, 3, 5, 9, 12, and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Buurman in view of Patra as applied to claims 1 and 14 above, and in further view of Zimmerman et al. [US 2010/0302525, US 6,455,862 and US 7,532,308 are incorporated by reference (see [0150])].
For claim 2, Buurman teaches the drift correction is determined using a uniformity compensator system (262, see [0055]-[0056], [0064], and [0076]-[0077]), wherein the uniformity compensator system comprises one or more uniformity compensators in one or more locations in a path of the illumination region to intercept one or more corresponding portions of the illumination region in the one or more locations (see Fig. 2), and determine, based on the drift of the illumination region or the drift in the attribute, an amount of adjustment to the one or more uniformity compensators to correct for the drift in the attribute (adjustment to correct non-uniformity by source control module extrapolation with given data, see [0055]-[0056], [0061], [0064], [0072], and [0076]-[0077]).
Buurman fails to teach using a uniformity sensitivity model embodied in the system is configured to determine adjustment.
Zimmerman teaches a uniformity sensitivity model embodied in the system is configured to determine adjustment (calculate positions of the uniformity correction device to compensate for drift, see Fig. 11 of the incorporated ‘308 Patent and [0141]-[0159] of Zimmerman).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide the uniformity sensitivity model as taught by Zimmerman in the adjustment of the compensator as taught by Buurman in order to determine the optimal position of the compensator.
For claim 3, Buurman fails to explicitly teaches the one or more uniformity compensators comprise one or more opaque finger members.
Zimmerman teaches the one or more uniformity compensators comprise one or more opaque finger members (see Fig. 7A).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide the uniformity compensators as taught by Zimmerman as the uniformity control module as taught by Buurman because the array of fingers provides selective control of the intensity profile.
For claims 5 and 12, Buurman teaches the reference position is an illumination slit position (330, see Fig. 6), but fails to explicitly teach determining the drift correction for each substrate within a lot and measuring at a start of an imaging of a substrate in a lot.
Zimmerman teaches determining the drift correction for each substrate within a lot and measuring at a start of an imaging of a substrate in a lot (measurement and correction of substrate 1-n in exposure of a lot, see Figs. 13-18).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide the correction sequence as taught by Zimmerman in the correction of exposure as taught by Buurman in order to ensure an accurate exposure for each substrate without unnecessary downtime to ensure throughput and quality.
For claims 9 and 17, Buurman teaches correcting the intensity distribution to provide uniform dose (see [0064], [0056], [0070], and [0072]), but fails to explicitly teach determining the drift is a dose drift with respect to a nominal dose, and the drift correction is a dose drift correction and/or the attribute is a pupil, wherein the drift in the attribute is a pupil drift with respect to a reference pupil, and the drift correction is a pupil drift correction.
Zimmerman teaches the drift is a dose drift with respect to a nominal dose, and the drift correction is a dose drift correction (calculation of corrections of intensity non-uniformity to ensure desired dose, see Fig. 4 and 5 and embodiments 6 and 7 and claims 1, 8 and 10 of the incorporated ‘862 Patent and [0141]-[0159] of Zimmerman) and/or the attribute is a pupil, wherein the drift in the attribute is a pupil drift with respect to a reference pupil, and the drift correction is a pupil drift correction.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide using the relationship between the intensity asymmetry and dose as taught by Zimmerman in the determination of the correction as taught by Buurman, because maintaining dose at a constant level reduces exposure error.
Response to Arguments
Applicant’s arguments with respect to claims 1, 14, and 20 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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 Steven H Whitesell whose telephone number is (571)270-3942. The examiner can normally be reached Mon - Fri 9:00 AM - 5:30 PM (MST).
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/Steven H Whitesell/Primary Examiner, Art Unit 1759
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