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 Suzuki et al. 20150062570, in view of Blasing-Bangert WO 2020161235, Pforr et al. DE 102006054820 and Hiroshima 20100159369, Mengel et al. WO 2012103933 and Lu et al. CN 214518289U
Suzuki et al. 20150062570 teaches an electrostatic chuck holding mechanism that has a structure in which an electrode layer is formed on a base body surface and a plurality of convex portions in contact with the mask rear surface is arranged on the electrode layer in a two-dimensional manner. The convex portions are arranged so as to be also in contact with the rear surface included in a pattern area of the mask. Therefore, the contact area between the electrostatic chuck holding mechanism and the mask rear surface becomes larger than that in a case of holding by the conventional vacuum absorption chuck. According to this, possibility that a particle adheres to the mask rear surface or the electrostatic chuck becomes higher. When the mask is held by using the electrostatic chuck holding mechanism in a state in which the particle adheres to the mask rear surface, flat mask clamping cannot be realized and there is a case in which an exposure pattern is not normally formed. Therefore, an exposure process is performed after performing mask rear surface inspection and allowing the particle of a predetermined size or a predetermined number of particles to adhere to the mask rear surface [0005-0006]. In an EUV exposure apparatus the mask 100 is held by the electrostatic chuck holding mechanism 50 in a vacuum chamber and an exposure process is performed. In the electrostatic chuck holding mechanism 50, a large number of convex portions 53 are in contact with the rear surface of the mask 100 as described above and the contact area increases, so that it is highly possible that the particle adheres to the electrostatic chuck holding mechanism 50 or the rear surface of the mask 100. When the mask 100 to which the particle adheres is held by the electrostatic chuck holding mechanism 50, flat mask clamping cannot be realized and there is a case in which an exposure pattern is not normally formed. Therefore, conventionally, rear surface inspection of the mask 100 is performed and, when there is the particle not smaller than a predetermined size or when the number of the particles is not less than a predetermined number, the mask 100 is cleaned [0026]. Therefore, in the first embodiment, the contact position or an estimated contact position of the rear surface of the mask 100 with the convex portion 53 of the electrostatic chuck holding mechanism 50 is obtained in the rear surface inspection of the mask 100 and they are made a convex portion contact region. A region other than this is made a convex portion non-contact region. Then, they are superimposed on a particle map indicating a position in which the particle is present obtained as a result of the rear surface inspection of the mask 100 and it is determined whether to clean the mask 100 while changing a determining criterion value being an allowable size of the particle between the convex portion contact region and the convex portion non-contact region [0028]. Thereafter, an inspector confirms the inspection images (step S12) and determines whether there are a plurality of images of specific particle which is brought into contact with the convex portion 53 of the electrostatic chuck holding mechanism 50 (traces of contact) (step S13). For example, in an example in FIG. 7, the inspection image 211-1 of the position 210-1 on the particle map 200 is the image of a scratch and the like on the mask rear surface and a granular object is indicated in the inspection image 211-5 of the position 210-5. In the inspection images 211-2, 211-3, 211-4, and 211-6 of other positions 210-2, 210-3, 210-4, and 210-6, respectively, the trace of contact with the convex portion 53 of the electrostatic chuck holding mechanism 50 is indicated. The trace of contact is formed when the particle is interposed between the convex portion 53 and the mask rear surface to be crushed, for example. At a processing step, the inspection image in which such trace of contact may be confirmed is extracted from the inspection images, and it is determined that whether there is a plurality of such images [0053].
PNG
media_image1.png
306
391
media_image1.png
Greyscale
Blasing-Bangert WO 2020161235 describes that if the backside of the EUV mask has unevenness, this is transferred to the front of the substrate when held in the chuck of the stepper (page 3/lines 7-15). The compensation of the rear surface unevenness can be facilitated by writing one of more arrangements of pixels into the mask substrate (8/32-9/5). When rotating or flipping a reflective photomask, it should be taken into consideration that said photomask is permitted to be held only in specific regions, in order to avoid contamination of the reflective mask or the production of defects in the active region thereof (10/18-21). The reflective photolithographic mask can have an electrically conductive coating of the rear side (11/8-9)
Furthermore, the device can comprise a laser system configured to introduce the at least one arrangement of pixels into a substrate of the reflective photolithographic mask. The laser system can be configured to generate light pulses having a time duration ranging from the picoseconds range to the femtoseconds range. Furthermore, the laser system can comprise a focusing unit configured to arrange a focus of a light beam at a predefined depth in the mask substrate. Moreover, the laser system can comprise a scanning unit configured to direct the light pulses of the laser system onto predefined positions of the substrate of the reflective photolithographic mask in order to generate the at least one arrangement of pixels (18/8-16). As explained in the context of the discussion of Fig. 4, local unevennesses 420 of the rear-side surface of the mask upon the transition from the measurement environment 150 into the operating environment 450 of the EUV mask 400 can lead to a local displacement of the pattern elements 350 thereof. This local displacement of the pattern elements 350 can be at least partly prevented and/or corrected. In this regard, it is possible, for example, by introducing one or more arrangements of pixels into the substrate 310 of the mask in the vicinity of the rear side 312, to smooth the local rear- side unevennesses 420 to the greatest possible extent, with the result that a local lateral displacement of the pattern elements 350 substantially does not occur. Alternatively or additionally, it is possible to introduce one or more arrangements of pixels into the mask substrate 310 in the vicinity of the front side 322 thereof, on which the multilayer structure 370 is deposited. Said last-mentioned arrangement(s) of pixels compensate(s) for the local displacements of the pattern elements 350 that occur upon the transition from the measurement environment 150 into the operating environment 450. Details with regard to determining and introducing arrangements of pixels into a substrate 310 of a mask 400 are specified in the patent specifications US 9 658 527 and US 9 753 366 in the name of the applicant. Finally, the flow diagram 1600 in Fig. 16 gives an overview of the sequence of a method for determining placements of pattern elements 350 of a reflective photolithographic mask 400 in the operating environment 450 thereof. The method begins in step 1610. Step 1620 involves determining surface unevenness data 420 of a rear side 315 of the reflective photolithographic mask 400 and/or surface unevenness data 930 of a mount 900 of the reflective photolithographic mask 400 in a measurement environment 150 that does not correspond to the operating environment 450 of the reflective photolithographic mask 400. This step can be carried out, for example by the first measuring unit 1100 and/or by the third measuring unit 1500. The specified method can be carried out by the device 1000 (41/31-24).
PNG
media_image2.png
258
373
media_image2.png
Greyscale
PNG
media_image3.png
237
370
media_image3.png
Greyscale
PNG
media_image4.png
400
335
media_image4.png
Greyscale
Pforr et al. DE 102006054820 (machine translation attached) teaches the correction of placement errors in photomask patterns by irradiating the substrate with a light beam to produce a density variation in a portion of the substrate. Another embodiment of the invention provides a method of correcting for placement errors of a plurality of features disposed on the surface of a substrate. The method comprises: a) determining lateral positions of the plurality of structural elements relative to a predetermined coordinate system, b) comparing the determined lateral positions of the plurality of structural elements with predetermined lateral position values for the plurality of structural elements and determining placement errors for the plurality of structural elements, c) transferring the structural elements onto a photoresist arranged on a wafer by means of photolithography in order to obtain photoresist structures, d) measuring mutual lateral distances of the photoresist patterns to determine linewidth variations; e) determining respective radiation doses for a plurality of light beams and determining a plurality of portions of the substrate in response to the plurality of determined placement errors and depending on the determined line width variations, f) performing local irradiations of the plurality of portions of the substrate with the plurality of light beams having the plurality of radiation doses to produce local density variations to reduce the placement errors [0005-0006]. This may be used with EUV photomasks [0008]. According to the present invention can the remaining placement errors V .sub.i 'of images 30 of structural elements 3 a photomask or an EUV mask and the placement errors of structural elements of a template by generating local density variations of the substrate 1 be further reduced. This can be achieved, for example, by coupling high-energy pulsed laser radiation, preferably by means of a femtosecond laser, into specific sections of the substrate 1 respectively [0044].
PNG
media_image5.png
208
197
media_image5.png
Greyscale
PNG
media_image6.png
220
409
media_image6.png
Greyscale
Hiroshima 20100159369 teaches with respect to figure 12c, the irradiation of a photomask through the front face between the light shielding features to form the subsurface void/cavity of figure 12d. [0051]
PNG
media_image7.png
179
228
media_image7.png
Greyscale
PNG
media_image8.png
112
246
media_image8.png
Greyscale
Lu et al. CN 214518289U (machine translation attached) teaches that dust/debris will interfere with the precision of femtosecond laser processing [0048-0049]
Mengel et al. WO 2012103933 describes with respect to figures 7 and 8, the use of femtosecond/picosecond laser treatment of the substrate to reduce the bumps/protrusions in the front surface of the photomask bank by dielectric breakdown of the silica. Figure 8 shows the use of an array of these f(830) formed at the focal volume/point of the laser (18/1-19/16)
PNG
media_image9.png
259
359
media_image9.png
Greyscale
PNG
media_image10.png
258
353
media_image10.png
Greyscale
The femtosecond laser system for the Ti sapphire laser
PNG
media_image11.png
220
335
media_image11.png
Greyscale
Suzuki et al. 20150062570 teaches mapping the particles on the rear surfaces of EUV photomasks, but does not teach the use of lasers to correct the mask pattern or adjusting the laser exposure based upon the position of the particles.
With respect to claim 1-2,4-10,12-15 and 17-19, it would have been obvious to one skilled in the art to modify the process of Suzuki et al. 20150062570 by using backside femtosecond laser exposure at different depths and positions within the substrate to correct the positions of the patterns as taught by Pforr et al. DE 102006054820 as well as for the unflatness/unevenness as taught by Blasing-Bangert WO 2020161235 at (41/31-24) and Mengel et al. WO 2012103933 ad (18//1-19/15), noting that the presence of dust/particles between the rear surface of the mask and the chuck is known to result in unflatness/unevenness as discussed at [0005-0006] of Suzuki et al. 20150062570 and to avoid exposure within the substrate adjacent to the particle in a manner similar to the avoidance of the light shielding layers in the frontside femtosecond exposure of Hiroshima 20100159369 and the disclosure in Lu et al. CN 214518289U that dust/debris will interfere with the precision of femtosecond laser processing [0048-0049].
With respect to claim 1-20, it would have been obvious to one skilled in the art to modify the process of Suzuki et al. 20150062570 by using backside femtosecond laser exposure at different depths and positions within the substrate to correct the positions of the patterns as taught by Pforr et al. DE 102006054820 as well as for the unflatness/unevenness as taught by Blasing-Bangert WO 2020161235 at (41/31-24) and Mengel et al. WO 2012103933 at (18//1-19/15) by forming an array of damaged areas to compensate for the unflatness as taught by Mengel et al. WO 2012103933 in figure 8 (18/1-19/15) and controlling the rep rate, pulsewidth. NA, pulse density and other laser parameters disclosed in Mengel et al. WO 2012103933 (table 1) to achieve the desired results, noting that the presence of dust/particles between the rear surface of the mask and the chuck is known to result in unflatness/unevenness as discussed at [0005-0006] of Suzuki et al. 20150062570 and to avoid exposure within the substrate adjacent to the particle in a manner similar to the avoidance of the light shielding layers in the frontside femtosecond exposure of Hiroshima 20100159369 and the disclosure in Lu et al. CN 214518289U that dust/debris will interfere with the precision of femtosecond laser processing [0048-0049]. This includes exposing within the substrate at different depths below the dust/particles as well as areas within the substrate spaced laterally as well as at different depths from the dust/particles. Note that adjusting the NA will inherently change the shapes of the focal volume.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Oshemkov et al. 20110255065 teaches the focusing of the femtosecond laser pulses from bumps occurring in the front surface to remove flatness imperfections in the EUV photomask [0092].
Oshemkov et al. WO 03071358 teaches with respect to figure 1b, a photomask which has undergone a laser treatment to form a shading or diffractive element (34) within the substrate in alignment with a void in the chrome layer (36). This blocks the exposure light and prevents printing of that void. [0061].
Dmitriev DE 102019121609 (machine translation attached) teaches with respect to figure 2, the correction of a photomask having a reflective area/layer (3) and an absorber layer/area, where the substrate is patterned/structured in the reflective layer areas [0024-0026].
Zait et al. 20050084767 teaches the use of lasers to repair damaged photomasks which include masks with undesired defects such as scratches, holes, lack or materials, excessive materials or other unintentional reasons in the chrome layer, anything other than the desired pattern. The mask pattern is corrected by writing a diffractive pattern or shading element (34) in the substrate adjacent to the undesired defect (42) in the chrome layer [0061,0068].
PNG
media_image12.png
438
424
media_image12.png
Greyscale
Mitsui 20060240335 teaches that where a particle is bitten between the contact surfaces of the mask and the chuck, the intended flat surface of the mask cannot be formed. In general, a particle is prevented is prevented probabilistically from being bitten by reducing the contact area of the chuck surface by several percents, but it is significantly difficult to control completely a particle on the back surface of the mask, and furthermore, the mask may not be retained with the sufficient chucking force by reducing the contact area. In this case, not only the warping deformation of the mask cannot be reformed, but also it is difficult to retain the mask [0010]
Miyajima et al. 20050093666 teaches in FIG. 9 an enlarged view of the mask chuck 115 and the mask stage 102 described above. There is a possibility that a foreign particle such as at 116 is sandwiched between the chucking surface of the mask chuck 115 and the mask 103, and it adversely influences the flatness of the mask 103. In consideration of it, the mask chuck 115 is demountably mounted to the mask stage 102, and the cleaning operation for the mask chuck 115 is carried out outside the vacuum chamber 107.
PNG
media_image13.png
273
412
media_image13.png
Greyscale
Caldwell et al. 20050087939 teaches with respect to figures 1-3, a particle between the chuck and the EUV photomask and the effect on the flatness [0015,0019].
PNG
media_image14.png
157
348
media_image14.png
Greyscale
PNG
media_image15.png
151
407
media_image15.png
Greyscale
PNG
media_image16.png
162
359
media_image16.png
Greyscale
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.
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, Ching-Yu (Coris) Fung can be reached at 571-270-5713. 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.
MARTIN J. ANGEBRANNDT
Primary Examiner
Art Unit 1737
/MARTIN J ANGEBRANNDT/Primary Examiner, Art Unit 1737 September 9, 2026
Prosecution Insights