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 .
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.
Response to Amendments/Arguments
Amendments made to claims 1, 7 and 16-19, as filed on November 7, 2025, are acknowledged.
Applicant’s arguments with respect to amended claims have been considered but are moot because the arguments do not apply to new ground(s) of rejection in this Office Action necessitated by the amendments made to the claims.
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 of this title, 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, 3, 5-11 and 13-14 are rejected under 35 U.S.C. 103 as being unpatentable over Bencher et al. (EP1998362) in view of Park et al. (Microelectronic Engineering, vol. 85, year 2008, pages 375-387).
Regarding claim 1, Bencher discloses a semiconductor processing method (abstract) comprising: forming plasma effluents of a hydrogen-and-fluorine-containing precursor (CH2F2 gas reads on a hydrogen-and-fluorine-containing precursor; paragraph 0027 and 0037); contacting a silicon-containing hardmask material and a photoresist material with the plasma effluents in a processing region of a semiconductor processing chamber (layer 304A comprising silicon nitride reads on a silicon-containing hardmask material, layer 302 is a photoresist material, paragraph 0027, Fig. 3A), wherein a substrate is disposed on a substrate support within the processing region (this is an inherent feature of a dry etching process), wherein an organic material is disposed on the substrate (layer 304B comprising carbon-based material reads on an organic material, paragraph 0027 and Fig. 3A), wherein the silicon-containing hardmask material is disposed on the organic material, and the photoresist material is disposed on the silicon-containing hardmask material (Fig. 3A), wherein the photoresist material has one or more apertures therein that allow the plasma effluents to access the silicon-containing hardmask material (paragraph 0027 and Fig. 3A), wherein the photoresist material comprises a dielectric material (paragraph 0027); and etching the silicon-containing hardmask material with the plasma effluents (paragraphs 0027 and 0037 and Fig. 3B).
Bencher is silent about etching the photoresist material with the plasma effluents; and while etching the photoresist material, etching the silicon-containing hardmask material with the plasma effluents at a selectivity greater than or about 10 relative to the photoresist material. However, Bencher discloses that the photoresist is used to transfer photoresist pattern into the silicon nitride 304A using a gas comprising CH2F2 (paragraph 0027). In addition, Park teaches a plasma process using a gas comprising CH2F2 for etching silicon nitride masked by a photoresist (abstract). In particular, Park teaches that the plasma etch process comprises: etching the photoresist material with the plasma effluents (section 3.1 and Fig. 1); and while etching the photoresist material, etching the silicon-containing hardmask material with the plasma effluents at a selectivity greater than or about 10 relative to the photoresist material (top two charts in Fig. 1 at a CH2F2 flow rate of 20 sccm). Therefore, it would have been obvious to one of ordinary skill, in the art before the effective filing date of the claimed invention, to use a known plasma process using a gas comprising CH2F2 for etching silicon nitride masked by a photoresist as taught by Park, in the method of Bencher for transferring the photoresist pattern into the silicon nitride layer, with a reasonable expectation of success. It has been held that combining prior art elements according to known methods to yield predictable results is obvious. See MPEP 2143 I.(A).
Regarding claim 3, Park discloses wherein a carrier gas is present when forming plasma effluents (Ar reads on a carrier gas, Fig. 1).
Regarding claim 5, Bencher discloses wherein silicon-containing hardmask material comprises a silicon-containing anti-reflective coating (silicon nitride, paragraph 0027).
Regarding claim 6, Bencher is silent about wherein one or more apertures are characterized by a critical dimension of less than or about 50 nm. However, it would have been obvious to one of ordinary skill, in the art before the effective filing date of the claimed invention, to choose a critical dimension based on required dimension for the etched structure, with a reasonable expectation of success.
Regarding claim 7, Bencher discloses wherein prior to etching the silicon-containing hardmask material, a thickness of the silicon-containing hardmask material is in the rage of 20-50 nm (paragraph 0027). Bencher further discloses that the first mask layer 304B has similar etch characteristics to the patterned photo resist
layer 302, the thicknesses of the patterned photoresist layer 302 and the first mask layer 304B are selected such that all portions of the patterned photoresist layer 302 remaining subsequent to the etch of the first hardmask layer 304A are removed
during the etch of the first mask layer 304B, and the total thickness of layer 304A and 304B is in the range of 4.06-5.625 times the target line width of the sacrificial mask 310 (paragraph 0028 and Fig. 3A). Because the target line width is approximately 40nm (paragraph 0023), the range for the total thickness of 304A and 304B is about 162nm to about 225nm. The layer thickness for layer 304B is therefore in the rage of about 112nm to about 205nm. Because the thickness of photoresist layer 302 is similar to the layer 304B (paragraph 0028 and Fig. 3A, the thickness of the photoresist is in the range of about 112nm to about 205nm. With the thickness of the silicon-containing hardmask material is in the rage of 20-50 nm (paragraph 0027), the aspect ratio of a thickness of the photoresist material to a thickness of the silicon-containing hardmask material is less than or about 10:1 and greater than 5:1.
Regarding claim 8, Bencher in view of Park discloses wherein after etching the silicon-containing hardmask material, an aspect ratio of a thickness of the photoresist material to a thickness of the silicon-containing hardmask material is greater than or about 4:1 (Bencher discloses that the thickness of the photoresist is in the range of about 112 nm to about 205nm, the thickness of the silicon-containing hardmask material is in the rage of 20-50 nm, see the rejection to claim 7 above for more details; Park discloses that the etch selectivity is greater than 20:1, Fig. 1; in the method of Bencher in view of Park, the thickness lost of the photoresist layer during the etch is less than 2.5nm).
Regarding claim 9, Bencher is silent about the thickness rage of the photoresist. However, it would have been obvious to one of ordinary skill, in the art before the effective filing date of the claimed invention, to choose a thickness for the photoresist film based on relative dimensions of the multilayer structure through routine experimentation. Additionally, where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable range by routine experimentation and there is no evidence of the criticality of the claimed range. See MPEP 2144.05 II.
Regarding claim 10, Bencher in view of Park fails to disclose wherein a pressure in the processing region is maintained at about 40 milliTorr or less. However, Park teaches that the pressure can be adjusted in the etch process (section 2). Additionally, where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable range by routine experimentation and there is no evidence of the criticality of the claimed range. See MPEP 2144.05II.
Regarding claim 11, Bencher discloses wherein the plasma effluents are generated at a plasma power of about 400 W (Fig. 1).
Regarding claim 13, Bencher is silent about wherein the photoresist material is configured for EUV patterning. However, Bencher discloses wherein the photoresist material is configured for a semiconductor lithographic process (paragraph 0015). EUV patterning is a well-known type of semiconductor lithographic process.
Regarding claim 14, Bencher discloses wherein after the etching of the silicon-containing hardmask material, the organic material is exposed (paragraph 0028).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Bencher et al. (EP1998362) in view of Park et al. (Microelectronic Engineering, vol. 85, year 2008, pages 375-387) as applied to claim 1 above, and further in view of Hama et al. (US20200328089).
Regarding claim 4, Bencher in view of Park is silent about the temperature in the processing region. However, Hama teaches a similar etching process using a gas comprising hydrogen and fluorine for etching a silicon-containing antireflection film masked by a photoresist wherein a temperature in the processing region is maintained at about −30° C or less paragraphs 0040-0041, 0049 and 0102). Therefore, it would have been obvious to one of ordinary skill, in the art before the effective filing date of the claimed invention, to use a known temperature in the processing region as taught by Hama, in the method of Bencher in view of Park for etching a silicon-containing antireflection film masked by a photoresist, with a reasonable expectation of success. It has been held that combining prior art elements according to known methods to yield predictable results is obvious. See MPEP 2143 I.(A).
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable Bencher et al. (EP1998362) in view of Park et al. (Microelectronic Engineering, vol. 85, year 2008, pages 375-387) as applied to claim 1 above, and further in view of Koshizawa et al.. (US20220020599).
Regarding claim 12, Bencher in view of Park is silent about wherein a chucking voltage of a power source of the semiconductor processing chamber is about 2000 volts or less. However, Koshizawa teaches that a chucking voltage applied to secure a substrate onto a support ranges from about 200 volts to about 2000 volts (paragraph 0045). Therefore, it would have been obvious to one of ordinary skill, in the art before the effective filing date of the claimed invention, to use known chucking voltage as taught by Koshizawa in the method of Bencher in view of Park for securing the substrate to the substrate support, with a reasonable expectation of success. It has been held that combining prior art elements according to known methods to yield predictable results is obvious. See MPEP 2143 I.(A).
Allowable Subject Matter
Claims 2 and 15 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
Regarding claim 2, the cited prior art of record, taken either alone or in combination, fails to disclose or render obvious a method wherein a volumetric ratio of the hydrogen-and-fluorine-containing precursor relative to other gases is greater than or about 50:1 when forming the plasma effluents, in the context of the instant claim. The closest cited prior art of Park discloses wherein a volumetric ratio of the hydrogen-and-fluorine-containing precursor relative to other gases is less than or about 1:15 (Fig. 1).
Regarding claim 15, the cited prior art of record, taken either alone or in combination, fails to disclose or render obvious a method wherein the hydrogen-and-fluorine-containing precursor is HF, in the context of the instant claim. The closest cited prior art of Bencher in view of Park discloses wherein the hydrogen-and-fluorine-containing precursor is a hydrofluorocarbon (Bencher, paragraph 0027; Park, abstract).
Claims 16-20 are allowed.
The following is an examiner’s statement of reasons for allowance:
Regarding claim 15, the cited prior art of record, taken either alone or in combination, fails to disclose or render obvious a method wherein a volumetric ratio of the hydrogen-and-fluorine-containing precursor relative to other gases is greater than or about 50:1 when forming the plasma effluents, in the context of the instant claim. The closest cited prior art of Park discloses wherein a volumetric ratio of the hydrogen-and-fluorine-containing precursor relative to other gases is less than or about 1:15 (Fig. 1).
Regarding claim 17, it is dependent on claim 16.
Regarding claim 18, the cited prior art of record, taken either alone or in combination, fails to disclose or render obvious a method comprising: forming plasma effluents of HF gas, in the context of the instant claim. The closest cited prior art of Bencher in view of Park discloses forming plasma effluents of hydrofluorocarbon gas (Bencher, paragraph 0027; Park, abstract).
Regarding claims 19-20, they are dependent on claim 18.
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 extension fee 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 date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JIONG-PING LU whose telephone number is (571) 270-1135. The examiner can normally be reached on M-F: 9:00am – 5:00pm. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Joshua L Allen, can be reached at telephone number (571)270-3176. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JIONG-PING LU/
Primary Examiner, Art Unit 1713