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 .
Election/Restrictions
Applicant's election with traverse of the species of the metallic tungsten corrosion inhibitor of “heteroaryl salts having an alkyl group with 5 to 30 carbon atoms” in the reply filed on 1/2/2026 is acknowledged. The traversal is on the ground(s) that searching for the both the species would not be a serious search burden as they are overlapping search area. This is not found persuasive because the metallic corrosion inhibitor of ammonium salt, represented by the formula (1) and the heteroaryl salt are patentable distinct with chemically different structure and so, they are deemed to lack of unity. Therefore, the species election is proper.
The requirement is still deemed proper and is therefore made FINAL.
Specification
The abstract of the disclosure is objected to because the abstract includes more than one paragraph. A corrected abstract of the disclosure is required and must be presented on a separate sheet, apart from any other text. See MPEP § 608.01(b).
Applicant is reminded of the proper language and format for an abstract of the disclosure.
The abstract should be in narrative form and generally limited to a single paragraph on a separate sheet within the range of 50 to 150 words in length. The abstract should describe the disclosure sufficiently to assist readers in deciding whether there is a need for consulting the full patent text for details.
The language should be clear and concise and should not repeat information given in the title. It should avoid using phrases which can be implied, such as, “The disclosure concerns,” “The disclosure defined by this invention,” “The disclosure describes,” etc. In addition, the form and legal phraseology often used in patent claims, such as “means” and “said,” should be avoided.
Claim Objections
Claims 5 and 8 are objected to because of the following informalities: in the both claims, the word “inhibiter” should have been spells out as “inhibitor”. Appropriate correction is required.
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.
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.
Claim(s) 1-8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al (US 2001/0053611) in view of JP 11-054510 ( provided with the IDS dated 9/20/2023; herein after JP-510) and further, in view of Chen et al (US 2016/0032186).
Regarding claim 1, Wang et al disclose a process for producing a semiconductor structure having a tungsten plug 206a, a metal barrier layer 204 comprising titanium nitride and a tungsten oxide film 208 [0015]-[0020]; the method comprises removing the tungsten oxide film 208; and after the step of removing the tungsten oxide film, removing the metal barrier layer 204 ([0015]-[0020] and Figure 2A-2C).
Wang et al fail to disclose the tungsten oxide is removed by a pretreatment agent includes at least one tungsten etchant selected form the group consisting of acids, ammonia and ammonium salts.
However, in the same field of endeavor, JP-510 discloses selective etching or removing tungsten oxide film by using a treatment agent such as hydrofluoric acid, hydrochloric acid, sulfuric acid, ammonia or choline (abstract; [0018]-[0023],[0026]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ JP-510's teaching of selectively etching tungsten oxide film into the teaching of Wang et al for selective removal of the tungsten oxide film on to the tungsten plug as suggested by JP-510.
The modified teaching above fails to disclose the barrier layer 204 (titanium nitride) is removed through contact with an etching agent.
However, Chen et al disclose a process for selectively etching titanium nitride using an etchant composition comprising for a semiconductor substrate for a memory element (abstract and [0010]), comprising an oxidizing agent (A) [0028], a fluorine compound (B) (HF, [0027], and a metal tungsten corrosion inhibiter (C) (abstract and [0032]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ Chen et al's teaching of selectively etching titanium nitride (TiN) relative to metal conductor tungsten [0043] into the teaching of JP-510 for efficiently selective etching the TiN as suggested by Chen et al.
Regarding claim 2, JP-510 discloses that the tungsten oxide removal is performed with alkali-based chemical [0022] and therefore a pH of the chemical solution appears to be falls with the claimed range of 0.1 to 13.
Regarding claim 3, JP-510 discloses selective etching or removing tungsten oxide film by using a treatment agent such as hydrofluoric acid, hydrochloric acid, sulfuric acid, ammonia or choline [0018]-[0023],[0026].
Regarding claim 4, in the above modified teaching, since a portion of the titanium nitride layer 204 is exposed during the step (I) of tungsten oxide etching, it would have been obvious that titanium oxide being formed by oxidation and obviously removed during step (I) with the contact of the tungsten oxide removal etchant solution.
Regarding claim 5, Chen et al disclose that the content of the oxidizing agent is about 0.0001 to about 2%; etchant (HF) is about 0.01 to about 10wt%; and the corrosion inhibitor is about 0.0001 to about 10 wt% (see Table 1) and therefore, the addition ratios of the oxidizing agent, etchant (HF) and the metal corrosion agent appears to overlaps the claimed ranges and overlapping ranges are prima facie obvious, see MPEP 2144.05.
Regarding claim 6, Chen et al disclose the oxidizing agent include but are not limited to, hydrogen peroxide (H.sub.2O.sub.2), periodic acid, iodic acid, etc. [0028]; and aforesaid “iodic acid” reads on the claimed oxidizing agent is halogen oxoacids and peroxy acids include hydrogen peroxide (as acknowledged by the applicant in [0062]-[0063] of specification).
Regarding 7, Chen et al disclose that the etchant composition includes, but are not limited to, HF, ammonium fluoride, tetrafluoroboric acid, hexafluorosilicic acid, etc. [0027].
Regarding 8, Chen et al disclose that metal tungsten corrosion inhibitor comprises benzyldimethyldodecylammonium chloride, myristyltrimethylammonium bromide, dodecyltrimethylammonium bromide, hexadecylpyridinium chloride, cetylpyridinium chloride, etc. [0032]; and at least aforesaid “cetylpyridinium chloride” reads on the elected species of heteroaryl salt having an alkyl group with 5-30 carbon atoms.
Cetylpyridinium chloride (CPC) is a cationic quaternary ammonium compound (C21H38ClN) consisting of a positively charged pyridinium headgroup (a pyridine ring with a positive nitrogen) attached to a 16-carbon hydrophobic cetyl (hexadecyl) chain, balanced by a chloride anion (source: Google).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Barnes al (US 2015/0027978) disclose a process for selective etching titanium nitride relative to tungsten [0005], wherein the composition comprises said composition comprising at least one oxidizing agent, at least one etchant, at least one metal corrosion inhibitor, and at least one solvent [0007],[0029]; and a pH value of 5-10 [0028]; and the corrosion inhibitor includes benzyldodecyldimethylammonium chloride [0033]. Hong et al (US 2022/0049160) disclose a useful tungsten corrosion inhibitors include heterocycles such as pyridine, quinoline, quinazoline, isoquinoline, pyrazine, pyrimidine, pyridazine, quinoxaline, phenazine, phenanthridine, 2,2′-pyridine, 1,4′-pyridine, 4,4′-pyridine, and acridine, as well as derivatives of the heterocycles including at least one of C.sub.1-6 alkyls, phenyl, benzyl, phenethyl, 3-phenylpropyl, benzyloxy, carboxyl, chloro, bromo, methoxy, nitro, and cyano groups, including, but not limited to, 2-benzylpyridine, and 4-(4-nitrobenzyl)pyridine, It will be obvious to those skilled in the art that, while quaternary salts are available commercially most often as chlorides or bromides [0031].
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHAMIM AHMED whose telephone number is (571)272-1457. The examiner can normally be reached M-TH (8-5:30pm).
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SHAMIM AHMED
Primary Examiner
Art Unit 1713
/SHAMIM AHMED/ Primary Examiner, Art Unit 1713