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 .
Specification
The specification submitted 3/8/2024 has been accepted by the examiner.
Drawings
The drawings submitted on 3/8/2024 have been accepted by the examiner.
Information Disclosure Statement
The information disclosure statements (IDS) submitted up to this point have been considered by the examiner.
Election/Restriction
Election was made without traverse in the reply filed on 8/14/2026. Applicant has elected Group I, corresponding to claims 1-15.
The examiner acknowledges the applicant’s cancellation of claims 16-20.
The examiner also acknowledges new claims 21-25 which are deemed to be independent and distinct inventions. See the explanation below:
Claims 21-25 are directed to an invention that is independent and distinct from the invention elected in the reply filed 8/14/2026. Applicant elected, without traverse, Group I, claims 1-15, drawn to a method. Newly submitted claims 21-25 are drawn to a product: a semiconductor structure (claims 21-23) and a patterning structure (claims 24-25).
Applicant's assertion that claims 21-25 are readable upon elected Group I is not persuasive. Group I was defined as claims 1-15, a method of photolithography. Claims 21 and 24 are product claims and are not methods. That the claimed structure may be produced by the elected method does not place it within the elected invention; that relationship is what renders the inventions distinct as process of making and product made.
The inventions are distinct as process of making and product made. The product as claimed can be made by another materially different process. Claims 21 and 24 recite no limitation directed to the manner of formation: no etch chemistry, no selectivity to the anti-reflective coating or the hard mask, and no trimming step. And therefore, they read on a structure in which the sacrificial organic layer pillar is laterally inset from the anti-reflective coating portion by spacer-defined patterning, by directional or conformal deposition, or by a lift-off process, none of which is within the scope of the elected method.
Restriction for examination purposes as indicated is proper because all the inventions listed in this action are independent or distinct for the reasons given above and there would be a serious search and/or examination burden if restriction were not required because one or more of the following reasons apply:
the inventions have acquired a separate status in the art in view of their different classification
the inventions have acquired a separate status in the art due to their recognized divergent subject matter
the inventions require a different field of search (e.g., searching different classes /subclasses or electronic resources, or employing different search strategies or search queries).
A serious search and examination burden exists because the product claims are not limited to the elected process, their field of search extends beyond H10P 76/2043 and H10P 50/286 to the formation and mask-creation routes of H10P 14/00, H10P 76/202, and H10P 76/4085, which the elected method does not require.
Since applicant has presented new claims directed to an invention distinct from and independent of the invention previously elected, the examiner deems the new claims 21–25 to be withdrawn from consideration. See 37 CFR 1.145 and MPEP § 821.03.
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 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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-8 and 13-15 are rejected under 35 U.S.C. 103 as being unpatentable over Luong-458 (US # 20120244458) in view of Han-438 (US # 20220246438).
Regarding Claim 1, Luong-458 teaches a method comprising:
providing an initial structure comprising a substrate (200, [0032], Fig. 2A), a hard mask (210; [0035] teaches a SiN hard mask) outward of the substrate, a sacrificial organic layer (222; [0039]) outward of the hard mask, an anti- reflective coating (224, [0038]) outward of the sacrificial organic layer, and a patterned photoresist (226, [0037]; pattern 230, [0040]) outward of the anti-reflective coating;
etching the initial structure to remove portions of the sacrificial organic layer (222, [0042, 46]) and the anti-reflective coating (224, [0042]) not protected by the patterned photoresist (see Fig. 2C) down to the hard mask (210, see Fig. 2C), to form sacrificial organic layer pillars (remainders of 222, 231, 231’; [0046]) under the patterned photoresist (shown in Fig. 2C); and
trimming a critical dimension (CD) (the width of the remainders of 222) of the sacrificial organic layer pillars (222) by etching with a gas ([0047-48]) [[that is selective to the anti-reflective coating and the hard mask]] to trim sidewalls of the sacrificial organic layer pillars ([0052, 75], over-etching the intermediate mask layer to reduce the line CD; see also [0030]).
Although Luong-458 discloses much of the claimed invention, it does not explicitly teach the method of trimming by etching with a gas that is selective to the anti-reflective coating and the hard mask.
Nonetheless the prior art before the effective filing date of the claimed invention renders such non-explicit feature differences obvious, as explained below.
For example, Han-438 is in the same or analogous field (plasma patterning of a multilayer mask having an organic layer between an anti-reflective coating 440 and an underlying etch-stop layer 420), and it teaches a method of etching a sacrificial organic layer (430) with a gas ([0052] describes the gas mixture) that is etch-selective to the organic layer in both directions: upward, with respect to an anti-reflective coating (440; SiARC anti-reflective coating) and downward with respect to a hard mask (420; titanium nitride underlayer).
A person having ordinary skill in the art would have recognized that modifying the trim the sacrificial organic layer pillars of Luong-458 with the selective gas etchant suggested by Han-438 would be obvious. Specifically, the modification suggested by Han-438 would be to employ a method of trimming by etching with a gas that is selective to the anti-reflective coating and the hard mask. The purpose of the Han-438 gas etching is to remove sidewall material from the pillar without eroding the anti-reflective coating that masks it or gouging the hard mask into which the pattern is subsequently transferred, thereby preserving CD control and pattern-transfer fidelity. The combination is one of known elements by known methods yielding predictable results, with a reasonable expectation of success because Luong-458 already performs the trim in the same chamber with the same class of process gases ([0048, 74]). Further, it has been held by the courts that selection of a prior art material based on its suitability for its intended purpose is within the level of ordinary skill. In re Leshing, 125 USPQ 416 (CCPA 1960) and Sinclair & Carroll Co. v. Interchemical Corp., 65 USPQ 297 (1945).
Regarding Claim 2, Luong-458 teaches the method of claim 1, wherein, in the providing step, the sacrificial organic layer of the initial structure comprises an organic planarization layer (OPL) (222 comprises an ODL or OPL; see [0039, 74]).
Regarding Claim 3, Luong-458 teaches the method of claim 1, wherein, in the providing step, the sacrificial organic layer of the initial structure comprises an amorphous carbon layer (see [0039]).
Regarding Claim 4, Luong-458 teaches the method of claim 1, wherein, in the providing step, the anti-reflective coating of the initial structure comprises silicon-containing antireflective coating (SiARC) (see [0038]).
Regarding Claim 5, Luong-458 teaches the method of claim 4, wherein, in the providing step, the hard mask comprises silicon nitride (SiN) (see [0035]).
Regarding Claim 6, Luong-458 teaches the method of claim 5, wherein, in the trimming step, the etching comprises plasma etching using the gas ([0047]).
Regarding Claim 7, Luong-458 teaches the method of claim 6, wherein the gas is a gas mixture comprising a carrier gas (optional noble gas; [0047-48]) that is non-reactive to the sacrificial organic layer and a gas selected from the group consisting of carbon dioxide and carbon monoxide ([0048]).
Regarding Claim 8, Luong-458 teaches the method of claim 7, wherein the carrier gas is selected from the group consisting of argon, neon, helium, xenon, and nitrogen ([0047-48]).
Regarding Claim 13, Luong-458 teaches the method of claim 6, wherein, in the trimming step, the etching comprises inductively coupled plasma etching ([0069, 70, 78]).
Regarding Claim 14, Luong-458 teaches the method of claim 6, wherein, in the trimming step, the etching comprises capacitively coupled plasma etching ([0059, 66, 73, 78]).
Regarding Claim 15, Luong-458 teaches the method of claim 6, wherein, in the trimming step, the etching comprises electron cyclotron resonance plasma etching ([0071, 78]).
Claims 9 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Luong-458 (US # 20120244458) in view of Han-438 (US # 20220246438) and further in view of Sone-871 (US # 20100170871).
Regarding Claim 9, nitrogen appears in Luong-458 only as one of several optional additive gases in the separate silicon containing-ARC etch ([0042]), and Han-438 pairs nitrogen with hydrogen rather than with carbon dioxide ([0052]).
Although Luong-458 in view of Han-438 discloses much of the claimed invention, it does not explicitly teach the method of claim 6 wherein the gas is a gas mixture comprising argon, nitrogen, and carbon dioxide.
Nonetheless the prior art before the effective filing date of the claimed invention renders such non-explicit feature differences obvious, as explained below.
For example, Sone-871 is in the same or analogous field (plasma trimming of an organic mask film in a stack having a bottom anti-reflection coating film on a thin film made of SiN), and it teaches carbon dioxide and nitrogen together as one trimming gas mixture, with an inert gas addable to that mixture: the inert gas may be Ar gas or N2 gas ([0067)); a gas mixture including CO2 may be used as the oxygen-containing gas ([0068]); combinations of CO2+O2, CO2+CO, CO2+CO+O2, CO2+H2O+O2, CO2+CO+H2O, CO2+N2, and CO2+H2 are used as the gas mixture including CO2, and various inert gases may be added to these combinations ([0069]). Sone-871 shows the resulting trim at Fig. 2A(d), the patterns 104a trimmed into the patterns 104b with the anti-reflection coating 103 and the silicon-nitride film 102 both remaining ([0066]). Sone-871 is relied on only for the composition of its trimming gas mixture; the layer order, which is the reverse of claim 1's, is not taken from it.
A person having ordinary skill in the art would have recognized that modifying the process composition used to pattern the intermediate mask of Luong-458 in view of Han-438 with the gas mixture suggested by Sone-871 would be obvious. Specifically, the modification suggested by Sone-871 would be to employ a method of claim 6 wherein the gas is a gas mixture comprising argon, nitrogen, and carbon dioxide. Selecting one member of a set of alternatives a reference expressly identifies as suitable for the same purpose, and adding a diluent the same reference expressly authorizes, is a choice among a finite number of identified. predictable solutions requiring no more than ordinary skill. The resulting mixture is one Luong-458 is already equipped to deliver, since it recites setting the flow rate of each gas as a process parameter ([0049]) and already provides for a noble gas ([0047]).
Regarding Claim 10, Sone-871, as applied to claim 9, teaches the method wherein the trimming is carried out for 5 to about 400 seconds (an overlapping range of trimming process timing, which may be carried out for about 60 sec. through 600 sec., [0066]).
Claims 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over Luong-458 (US # 20120244458) in view of Han-438 (US # 20220246438) and further in view of Sone-871 (US # 20100170871) and further in view of Isii-846 (US # 20150118846).
Regarding Claim 11, Luong-458 teaches setting a temperature condition for the plasma processing system and for the substrate or substrate holder among its process parameters ([0049]) but states no numerical window, and Sone-871 states only that the substrate temperature may be 300 degrees C or less, preferring room temperature ([0067]).
Although Luong-458 in view of Han-438 and Sone-871 discloses much of the claimed invention, it does not explicitly teach the method wherein the trimming is carried out at a temperature in a range from about 40°C to about 200°C.
Nonetheless the prior art before the effective filing date of the claimed invention renders such non-explicit feature differences obvious, as explained below.
For example, Isii-846 is in the same or analogous field (controlling the rate and across-substrate uniformity of a plasma trim of a carbon-containing film, expressly including spin-on-carbon (SOC) material and carbon-containing film produced by CVD or PVD), and it teaches controlling the trimming rate at 55 nm/min or less by controlling the susceptor temperature at lower than 85 degrees C, e.g., in a range of 40 degrees C to 80 degrees C ([0054]). The disclosed 40 to 80 degrees C window falls entirely within the claimed range.
A person having ordinary skill in the art would have recognized that modifying the substrate-holder temperature condition of Luong-458 with the window taught by lsii-846 would be obvious. Specifically, the modification suggested by Isii-846 would be to employ a method wherein the trimming is carried out at a temperature in a range from about 40°C to about 200°C. Isii-846 identifies susceptor temperature as one of an enumerated set of parameters: flow rate of the oxygen-containing gas, flow rate of the nitrogen-containing gas, pressure, RF power, duty cycle of RF power, electrode spacing, and susceptor temperature ([0046]), by which the trimming rate of a carbon-containing film is deliberately held at or below a target value. A controlled trim rate is what makes a small CD reduction reproducible, which is the objective Luong-458 pursues through its parametric CD control ([0029, 52]).
Regarding Claim 12, Luong-458 teaches the method of claim 11, wherein the trimming is carried out at a pressure in a range from 4 mTorr to about 100 mTorr ([0073]).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTOPHER A JOHNSON whose telephone number is (571)272-9475. The examiner can normally be reached on normally working Monday-Friday between 9 am and 6 pm Pacific Time.
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, Dale Page can be reached on 571-270-7877. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/CHRISTOPHER A JOHNSON/ Primary Examiner, Art Unit 2899
Prosecution Insights