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 .
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-8, as to the point that the applied prior art fail to teach or suggest the content of the tungsten oxide etchant as required in the currently amended claim 1, have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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 1-8 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.
Regarding claim 1, the phrase "to remove at least a part of the tungsten oxide film" renders the claim indefinite because it is unclear whether how the specified content of 0.03 to 3 % of the tungsten oxide etchant in the pretreatment agent will remove tungsten oxide, if the substrate contains “titanium and titanium alloy”? because, the titanium and titanium alloy does not include “titanium oxide”.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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 ONO et al (US 2019/0352537) 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.
Modified Wang et al with JP-510 fail to teach the content of the tungsten oxide etchant to be from 0.03 to 3% by mass.
However, Ono et al disclose a metal-oxide dissolving agent for dissolving or removing tungsten oxide material, wherein the dissolving agent comprises inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid; and ammonium salts of the inorganic acids described above [0066],[0067]; and the content of the metal oxide-dissolving agent is preferably 0.001 mass % or more, more preferably 0.002 mass % or more, further preferably 0.005 mass % or more, particularly preferably 0.01 mass % or more, extremely preferably 0.05 mass % or more, very preferably 0.1 mass % or more, and even more preferably 0.2 mass % or more, based on the total mass of the polishing liquid [0068]; and aforesaid range encompasses the claimed range of 0.03 to 3% by mass.
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 Ono et al's teaching of using the tungsten oxide dissolving/removing agent with the disclosed amount into the teaching of modified Wang et al for effective removal of tungsten oxide as taught by Ono et al.
The modified above teaching or Wang et al 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
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 nonprovisional extension fee (37 CFR 1.17(a)) 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 mailing date of this final action.
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
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