DETAILED ACTION
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 § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-20 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
As to claims 1, 9 and 15, the claims recite, in pertinent part, a gray-tone-pattern grating defined by a plurality of structures, followed by language indicating that “the structures” comprises an absorber layer disposed on the substrate. The metes and bounds of the claimed subject matter are unclear because it is unclear whether each individual structure has a respective absorber layer; the plurality of structures collectively has a common absorber layer or the plurality of structures is formed in, patterned from or otherwise defined by portions of a common absorber layer.
For purposes of prior art examination only, and without waiving the foregoing rejection, the Examiner interprets the limitation broadly as requiring an absorber material/layer disposed on the substrate and patterned or otherwise configured to provide the recited plurality of grating structures. Thus, prior art need not disclose a physically separate absorber layer associated with each individual structure. A reference disclosing a common absorber layer patterned into a plurality of grating features is considered to satisfy this limitation under the above interpretation.
Also, the claim recite that the gray-tone pattern grating has: a pitch that is less than or equal to an exposure wavelength of light to pass through the structures”. The scope of the limitation is unclear because the claims do not positively recite or otherwise define the “exposure wavelength” against which the claimed pitch is to be compared. In particular, the claims do not specify a particular exposure source, exposure wavelength, wavelength range or exposure operation that establishes the value of the recited “exposure wavelength”. Accordingly, whether a particular pitch satisfies the limitation may depend upon an external and unspecified exposure wavelength selected for use with the mask.
For purposes of examination, the Examiner interprets “an exposure wavelength of light” as a wavelength of radiation with which the claimed mask is intended or capable of being used during a lithographic exposure process.
As to claims 2 and 10, the limitation of “in a range from about 25nm to about 25nm less than the pitch” is indefinite because the lower endpoint is an absolute value, approximately 25nm, while the upper endpoint is defined relative to the pitch and the claims from which claims 2 and 10 depend on do not establish a minimum pitch sufficient to ensure that the recited range exists.
For purpose of examination, the Examiner interprets the limitation, where mathematically meaningful as: 25nm ≤ critical dimension ≤ pitch-25nm).
Claim Rejections - 35 USC § 102
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.
Claims 1, 9, 12, 15-18 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Komine et al (U.S.Pat. 7,092,068 B2).
Regarding claims 1 and 15, Komine discloses a mask/reticle (4) and a corresponding method of fabricating the mask comprising substantially all features of the instant claims such as: a transparent substrate (5) and an exposure monitor pattern/a gray-tone pattern formed thereon. In particular, Komine discloses the gray-tone pattern (16) having a diffraction grating with a plurality of opaque films/absorber layer (6a-6m) provided on the transparent substrate (5), wherein the widths of the opaque films are varied at a fixed pitch P so that the opening ratio and resulting optical transmittance vary across the grating (see figures 7A-7B and the discussion thereto; see col.6, lines 40-57). Komine further expressly teaches that the grating pitch is selected sufficiently small that the diffraction grating pattern is not resolved on the exposed substrate. In the disclosed embodiment, the exposure wavelength is 248 nm, the calculated maximum pitch is approximately 234 nm and Komine selects P=190 nm. Thus, Komine expressly teaches a grating pitch less than the exposure wavelength (see Komine, Figure 7 and accompany discussion).
As to claims 9, 12 and 16-18, Komine (see figure 6) further discloses a substrate (1); UV light source (41) disposed above the mask (4) operable to project UV light through the mask and a substrate support (48) positioned below the mask.
Claim Rejections - 35 USC § 103
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 2-8, 10-14 and 19-20 are unpatentable over Komine et al (U.S.Pat. 7,092,068 B2) in view of Lee et al (U.S.Pat. 7,545,520).
With respect to claims 2 and 10, Komine does not expressly disclose the structure width as a “critical dimension” having the particular claimed ranges, as claimed. Lee teaches a mask having a sub-wavelength grating comprising a regular array of features and spaces wherein the pitch or the array is smaller than the wavelength of the beam of light (see col.2, lines 18-22). Lee further expressly teaches sub-wavelength gratings and defines the short dimension/linewidth of a grating feature as its critical dimension (CD) and the direct geometrical relationship: F=CD/pitch where F represent filling factor.
In view of such teachings, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to characterize and select the widths of Komine’s opaque grating structures according to Lee’s known CD/pitch relationship because Komine already deliberately varies structure width at a fixed pitch to obtain the desired opening ratio/transmission. The particular recited range of approximately 25 nm to approximately 25 nm less than the pitch represents selection and optimization of a known result-effective dimensional variable. One of ordinary skill would have been motivated to optimize CD relative to pitch to obtain the desired filling factor and resulting optical transmission.
As to claims 3, 11 and 19-20, Komine does not expressly state the claimed numerical range of approximately 30-150 nm, it would have been obvious to optimize the thickness of Komine’s absorbing films to obtain a desired optical transmission profile. Selection of the claimed thickness range would therefore have amounted to routine optimization of a known result-effective variable.
As to claim 4, Komine teaches two-dimensional arrangements of diffraction grating monitor structures, including gratings extending in different orientations but the presently identified disclosure does not expressly disclose contact-hole and pillar structures. These structures are well known in the art. It would have been obvious to a skilled artisan to employ the contact-hole and pillar structures onto the gray-tone pattern grating of Komine for the purpose of generating a desired pattern as intended by Komine.
As to claim 5, Komine discloses the structures are oriented in a line and space pattern (see figure 2).
With respect to claims 6-8, for the thickness of the substrate and the materials of the substrate as recited in the claim, Komine already establishes the conventional lithographic reticle environment, including transparent substrate and opaque pattern material as discussed above. To the extent these claims merely specify conventional dimensions of the mask substrate or conventional materials, such values would have been obvious selections to a skilled artisan based upon known mechanical, optical, fabrication and handling requirements of the lithographic masks.
As to claim 12, Komine discloses a mask having substantially all limitations of the instant claims except for the diameter of the mask in the range of about 299.5 mm to about 300.5 mm. As a matter of choice, it would have been obvious to a skilled artisan to select the mask having the diameter in the range of 299.5mm to about 300.5 mm for the purpose of generating a desired pattern.
As to claims 13-14, Komine (see figure 6) further discloses a substrate (1); UV light source (41) disposed above the mask (4) operable to project UV light through the mask and a substrate support (48) positioned below the mask and the mask is positioned in a mask holder. It is noted that selection of which surface of a transmissive mask faces toward or away form the substrate would have been a predictable orientation choice based upon the particular projection geometry, mask construction and contamination/handling requirement, absent a claimed unexpected result associated with one orientation.
Prior Art Made of Record
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Kraus et al (U.S.Pat. 12,663,370); Koolen et al (U.S.Pat. 12,436,470) disclose masks for use in lithographic devices and have been cited for technical background.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to HUNG HENRY NGUYEN whose telephone number is (571)272-2124. The examiner can normally be reached Monday-Friday 7:00AM-4:30PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Toan Minh Ton can be reached at 571-272-2303. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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HUNG HENRY NGUYEN
Primary Examiner
Art Unit 2882
Hvn
8/19/26
/HUNG V NGUYEN/ Primary Examiner, Art Unit 2882
