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 Objections
Claim 4 is objected to because of the following informalities: in the claim, lines 3-4, there are gaps between words. Appropriate correction is required.
Claim Rejections - 35 USC § 102
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 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.
Claim(s) 1-2,4-5,7-9,14-15,18 and 20 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Tapily (US 2017/0243755).
Regarding claim 1, Tapily discloses a method for atomic layer etching (ALE) of a substrate containing a metal oxide film (abstract), the method includes providing a substrate containing a metal oxide film, exposing the substrate to a fluorine-containing gas to form a fluorinated layer on the metal oxide film, and thereafter, exposing the substrate to an aluminum-containing gas to remove the fluorinated layer from the metal oxide film. The exposing steps may be alternatingly repeated at least once to further etch the metal oxide film [0005], [0017], wherein the “fluorine-containing gas” reads on the claimed “first precursor including a fluorinated material”; and the “aluminum-containing gas” reads on the “second precursor including a metal halogenated material”.
Tapily discloses that the substrate 300 is exposed to an aluminum-containing gas 308 to react with and remove the fluorinated layer 304. The reaction byproducts include volatile species that desorb from the substrate 300 and are efficiently pumped out of the process chamber [0020].
Regarding claim 2, Tapily discloses that fluorine-containing gas (first precursor) may be selected from hydrogen fluoride (HF) and nitrogen trifluoride (NF.sub.3) [0018].
Regarding claim 4, Tapily discloses that the aluminum-containing gas can contain an organic aluminum compound. In one example, the aluminum-containing gas may be selected from the group consisting of AlMe.sub.3 (trimethylaluminum, TMA) [0018], [0024].
Regarding claim 5, Tapily discloses that the process chamber may be purged with an inert gas (e.g., argon (Ar) or nitrogen (N.sub.2)) to remove excess fluorine-containing gas and reaction byproducts ([0019], Figure 2).
Regarding claim 7, Tapily discloses that the metal oxide film (layer) may be selected from the group consisting of Al.sub.2O.sub.3, HfO.sub.2, TiO.sub.2, ZrO.sub.2, Y.sub.2O.sub.3, La.sub.2O.sub.3, UO.sub.2, Lu.sub.2O.sub.3, Ta.sub.2O.sub.5, Nb.sub.2O.sub.5, ZnO, MgO, CaO, BeO, V.sub.2O.sub.5, FeO, FeO.sub.2, CrO, Cr.sub.2O.sub.3, CrO.sub.2, MnO, Mn.sub.2O.sub.3, RuO, and combinations thereof [0018].
Regarding claim 8, Tapily discloses that exposing the substrate to a fluorine-containing gas to form a fluorinated layer on the metal oxide film, and thereafter, exposing the substrate to an aluminum-containing gas to remove the fluorinated layer from the metal oxide film; and the exposing steps may be alternatingly repeated at least once to further etch the metal oxide film [0005]; and the total amount of material removed is determined by the number of repeated cycles [0017].
Regarding claim 9, Tapily discloses that providing a substrate, and in 104, alternatingly exposing the substrate to fluorine-containing gas and an aluminum-containing gas to etch the substrate or a film on the substrate. The substrate may be heated to a temperature between 100° C. and 400° C. [0018]; and aforesaid temperature range is encompassing the claimed range of 150 to 300 degree C.
Regarding claims 14-15, Tapily discloses that the alternating exposures are performed in the absence of plasma excitation and may be repeated at least once to further etch the substrate. According to one embodiment, the substrate contains a metal oxide film that is etched by the alternating exposures. For example, the fluorine-containing gas may be selected from hydrogen fluoride (HF) and nitrogen trifluoride (NF.sub.3). In one example, the aluminum-containing gas can contain an organic aluminum compound. In one example, the aluminum-containing gas may be selected from the group consisting of AlMe.sub.3 (trimethylaluminum, TMA), AlEt.sub.3, etc. [0018],[0024].So, the second precursor (aluminum-containing gas) is in a gaseous state 9as of claim 14) and no plasma gas is provided during the exposing with the first and the second precursor gas (as of claim 15).
Regarding claim 18, Tapily discloses above for the claim 1 (same process steps recited in claim 18), except the preamble of claim 18, requires a method of making a “semiconductor device” (see, the rejection for claim 1, above).
Tapily also disclose the invention provide a method for manufacturing of semiconductor devices, and more particularly, to ALE using a fluorine-containing gas and an aluminum-containing gas [0018].
Regarding claim 20, discloses that the metal oxide film (layer) may be selected from the group consisting of Al.sub.2O.sub.3, HfO.sub.2, TiO.sub.2, ZrO.sub.2, etc. [0018].
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) 3,6,10-13,16-17 and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tapily (US 2017/0243755) as applied to claims 1 and 18 above, as supported with Google.
Regarding claim 3, Tapily discloses above for the claim 1 but fails to teach the aluminum-containing gas (corresponds to the second precursor) comprises from the list as of claim 3.
However, Tapily discloses that the aluminum-containing gas may be selected from AlCl.sub.3, AlBr.sub.3, AlI.sub.3, Al(O-i-Pr).sub.3, [Al(NMe.sub.2).sub.3].sub.2, Al(i-Bu).sub.2Cl, Al(i-Bu).sub.3, Al(i-Bu).sub.2H, AlEt.sub.2Cl (diethylaluminum chloride), etc. [0018].
However, it would have been obvious to select dimethylaluminumchloride instead of diethylaluminum chloride because it was well established that the substitution of methyl for hydrogen on a known compound is not a patentable modification absent unexpected or unobvious results or that hydrogen and methyl are deemed obvious variants. For example, it is obvious to prepare a -NHMe containing compound when the art teaches a –NMe2 containing compound with a reasonable expectation of success. Specifically, a –NHMe and –NMe2 are considered homologues and are obvious absent unexpected results. In In re Wood, 582 F.2d 638, 199 USPQ 137 (CCPA 1978).
Regarding claim 6 and 11, Tapily discloses above that the metal oxide film may comprises zirconium dioxide (ZrO.sub.2); and zirconium oxide or zirconia, has a typical room-temperature dielectric constant (relative permittivity) ranging between 20 and 30, (Source:Google), which overlaps the claimed range of 10 or greater (as of claim 6) and 20 or greater (as of claim 11); and overlapping ranges are prima facie obvious, MPEP 2144.05.
Regarding claim 12, Tapily discloses above that the metal oxide film is exactly the same as the instant invention and expected to have the similar physical properties, such as the bandgap of the metal oxide layer.
Regarding claims 13 and 16-17, Tapily discloses that simplest ALE implementation consists of two sequential steps: surface modification (1) and removal (2). Modification forms a thin reactive layer with a well-defined thickness that is subsequently more easily removed than the unmodified material. The layer is characterized by a sharp gradient in chemical composition and/or physical structure of the outermost layer of a material. The removal step takes away at least a portion of the modified layer while keeping the underlying substrate intact, thus “resetting” the surface to a suitable state for the next etching cycle. The total amount of material removed is determined by the number of repeated cycles [0017]. Therefore, without showing any criticality of such etching rate and a thickness to be etched from the target surface, including the etching rate per cycle and the amount or thickness of the target surface to be removed depends on the type of precursors and several parameters or type of semiconductor to be manufactured, which one of ordinary skill in the art would have been optimize for predictable result.
Regarding claims 10 and 19, Tapily discloses above for the claims 1 and 18, but specifically fails to teach the aluminum-containing gas (corresponds to the second precursor) comprises from the list as of claims 10 and 19.
However, Tapily discloses the metal oxide film (layer) may be selected from the group consisting of Al.sub.2O.sub.3, HfO.sub.2, TiO.sub.2, ZrO.sub.2, etc. and that fluorine-containing gas (first precursor) may be selected from hydrogen fluoride (HF) and nitrogen trifluoride (NF.sub.3) [0018].
Tapily also discloses that the aluminum-containing gas may be selected from AlCl.sub.3, AlBr.sub.3, AlI.sub.3, Al(O-i-Pr).sub.3, [Al(NMe.sub.2).sub.3].sub.2, Al(i-Bu).sub.2Cl, Al(i-Bu).sub.3, Al(i-Bu).sub.2H, AlEt.sub.2Cl (diethylaluminum chloride), etc. [0018].
However, it would have been obvious to select dimethylaluminumchloride instead of diethylaluminum chloride because it was well established that the substitution of methyl for hydrogen on a known compound is not a patentable modification absent unexpected or unobvious results or that hydrogen and methyl are deemed obvious variants. For example, it is obvious to prepare a -NHMe containing compound when the art teaches a –NMe2 containing compound with a reasonable expectation of success. Specifically, a –NHMe and –NMe2 are considered homologues and are obvious absent unexpected results. In In re Wood, 582 F.2d 638, 199 USPQ 137 (CCPA 1978).
Claim(s) 3,10 and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tapily (US 2017/0243755) as applied to claims 1 and 18 above, and further in view of Woods et al (US 2020/0395222).
Regarding claims 3, 10 and 19, Tapily discloses above for he claims 1 and 18 but specifically fails to teach the aluminum-containing gas (corresponds to the second precursor) comprises from the list as of claims 3, 10 and 19.
However, in the same field of endeavor, Woods et al teach a process of ALE for metal oxide comprises hafnium oxide, etc. [0030], first exposing the metal oxide with a fluorinating agent to form a fluoride layer 620. The method 100 continues at operation 120 with the fluoride layer 620 being exposed to a halide etchant to remove the fluoride layer 620 [0029], wherein the halide etchant corresponds to the claimed “second precursor”; the fluorinating agent comprises one or more of HF, NF.sub.3 [0032], [0035]-[0037]; and the halide etchant comprises or consists essentially of one or more species with a general formula of MXy, where M comprises one or more of Ti, Sn, Mo, W or Nb, X comprises one or more of CI, Br or I, and y is 1-6 [0039]; and aforesaid teaching easily reads on the claimed titanium tetrachloride (TiCl4), if the metal is Ti, X=Cl and y is 4 in the formula above.
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 Woods et al's teaching of using the halide etchant to effectively remove the fluoride layer (620) into the teaching of Tapily et al for efficiently removing the fluoride or fluorinated layer as suggest by Woods et al.
Additionally, it would have been simple substitution of known materials for predictable results.
Conclusion
The prior art made of record, listed in the PTO-892 and not relied upon is considered pertinent to applicant's disclosure.
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SHAMIM AHMED
Primary Examiner
Art Unit 1713
/SHAMIM AHMED/ Primary Examiner, Art Unit 1713
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