DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 102
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.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim(s) 1, 4 is/are rejected under 35 U.S.C. 102(a)(1) and (a)(2) as being anticipated by Lin et al. US 2022/0199401A1 (hereinafter “Lin”).
Regarding claim 1:
Lin is directed to methods of depositing boron films (Abstract). Lin discloses that their method comprises (Fig 1A -1B): providing [depositing] a first material film 104 on a substrate ([0022] – [0023]); and providing [depositing] a second material film 106 directly onto the first material ([0023]; claims 1, 5, 6). The first material film may be inter alia aluminum oxide (claim 5) and the second film may be inter alia silicon nitride (claim 6). While Lin does not expressly teach a specific embodiment of their method of providing a first aluminum oxide layer and then providing a silicon nitride layer, the combination is anticipated in Lin as a person of ordinary skill in the art, upon reading Lin, would ‘at once envisage’ the claimed arrangement or combination." See Kennametal, Inc. v. Ingersoll Cutting Tool Co., 780 F.3d 1376, 1381, 114 USPQ2d 1250, 1254 (Fed. Cir. 2015).
Regarding claim 4:
Lin discloses that the substrate may be made of materials such as silicon and silicon oxide ([0039]).
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, 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 2, 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lin as applied to claims 1 and 4 above, and further in view of Liou et al. US 2020/0135552 A1 (hereinafter “Liou”).
Regarding claims 2, 3:
Lin does not expressly teach that the method further comprises treating the aluminum oxide (Al2O3) film with a plasma comprising nitrogen (N2) prior to depositing the silicon nitride film.
Liou is directed to methods of forming semiconductor structures, including dielectric etch stop layers over other dielectric layers (Abstract). Liou teaches that such dielectric layers or etch stop layers can be aluminum oxide layers ([0014], [0024]). Liou further discloses that aluminum oxide layers can be post-treated with a plasma for a suitable amount of time prior to the deposition of other sublayers in order to improve the film quality of the deposited aluminum oxide layer ([0029]). The post-treatment plasma can include nitrogen gas and can cure any potential pin holes or leak paths that may exist.
Therefore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to have modified the method of Lin by treating the aluminum oxide (A12O3) film with a plasma comprising nitrogen gas for a suitable time (optimizing meeting claim 3) prior to depositing the silicon nitride film because Liou teaches that such a post treatment prior to the deposition of other films improves film quality of the aluminum oxide film.
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lin as applied to claims 1 and 4 above, and further in view of Lee et al. US 20020068466 (hereinafter “Lee”).
Regarding claim 5:
Lin discloses that atomic layer deposition (ALD) processes are known for the deposition of films, such as boron films in the context of Lin ([0045] – [0047]).
Lin does not expressly teach that the deposition of the aluminum oxide film comprises an ALD process.
Lee is directed to methods of forming thin films onto substrates, including silicon nitride layer films and aluminum oxide films (Abstract; [0018], [0024]; claims 1, 6, 8). The films are formed by atomic layer deposition (Abstract, [0009], ([0017] – [0018]). Lee discloses that films deposited by ALD have excellent step coverage and uniformity, which are desired characteristics in semiconductor processing ([0003], [0005], [0028]).
Therefore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to have modified the method of Lin by depositing the aluminum oxide film by an ALD process because Lee teaches that such a technique, such as their disclosed technique, deposit films with excellent step coverage and uniformity.
Claim(s) 6 – 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lin as applied to claims 1 and 4 above, and further in view of AuBuchon et al. US 20220389571 A1 (hereinafter “AuBachon”).
Regarding claims 6, 7, 8, 9:
Lin discloses that atomic layer deposition (ALD) processes are known for the deposition of films, such as boron films in the context of Lin ([0045] – [0047]).
Lin does not expressly teach that the deposition of the silicon nitride film comprises a plasma enhanced atomic layer deposition (PEALD) process.
AuBachon is directed to inter alia methods of depositing dielectric films into semiconductor substrates, particularly substrates having gaps that are to be filled (Abstract; [0002] – [0003]). AuBachon discloses that the dielectric films may be silicon nitride films ([0021], [0056]) that are deposited by PEALD. PEALD allows for the deposition of continuous and conformal films that uniformly covers exposed surfaces ([0007], [0067] – [0068]). AuBachon discloses that their process comprises: exposing the semiconductor substrate to a silicon-containing precursor to absorb the precursor onto the semiconductor substrate ([0056], [0066]); and then exposing precursor-adsorbed semiconductor substrate to a dose of nitrogen-containing microwave-generated plasma derived from argon, nitrogen and ammonia [meeting claims 6, 7, 8, 9, 19] ([0064 – [0065]; claim 16, 19).
Therefore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to have modified the method of Lin by depositing the silicon nitride film according to a PEALD process such as that taught by AuBachon because AuBachon teaches that such processes allows for the deposition of continuous and conformal films that uniformly covers exposed surfaces, especially for semiconductor substrates having recesses or trenches that require gapfill.
Regarding claim 10:
Lin does not expressly teach that the semiconductor substrate is exposed to the
nitrogen-containing plasma mixture for a time period in a range of from 0.2 seconds to 4 seconds.
However, AuBachon discloses that process gases, such as those used to generate plasma, may be flowed into process chambers having to-be-processed semiconductor substrates in a time range between 0.1 seconds to about 90 seconds, including a range of about 1 second to about 30 seconds ([0063]).
In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66(Fed. Cir. 1997). See MPEP 2144.05.
Regarding claims 11 – 16:
Lin in view of AuBachon does not expressly teach that the exposure of the semiconductor substrate comprises a first plasma sequence and a second plasma sequence, and the particular gas combinations of exposure in each sequence as defined in claims 12 – 16.
However, the claim limitations amount to the splitting of a step into multiple substeps wherein each substep have a predictable result or perform the same function as the whole step.
Outside a showing of unexpected results, in general the transposition of process steps or the splitting of one step into two, where the processes are substantially identical or equivalent in terms of function, manner and result, was held to be not patentably distinguish the processes. Ex parte Rubin 128 USPQ 159 (PO BdPatApp 1959). See also In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960).
Claim(s) 17 – 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lin in view of Liou as applied to claims 2 – 3 above, and further in view of AuBachon.
Regarding claims 17 – 18:
Lin in view of Liou does not expressly teach the repetition of one or more operations of the method to deposit silicon nitride film to a predetermined thickness and having a microwave plasma source.
It would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to have modified the method of Lin in view of Liou by repeating of one or more operations of the method to deposit silicon nitride film to a predetermined thickness and having a microwave plasma source by employing a PEALD process because AuBachon teaches that such processes allows for the deposition of continuous and conformal films that uniformly covers exposed surfaces, especially for semiconductor substrates having recesses or trenches that require gapfill.
Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lin in view of AuBachon and Liou.
The recited limitations of present claim 20 amount to combinations of limitations of claims 1 – 19 above. The disclosure of Lin discussed above in the rejection of the claims apply to the present claim mutatis mutandis.
Lin does not expressly teach the recited treating of the aluminum oxide film with the recited plasma.
The disclosure of Liou and AuBachon above also apply to the present rejection, mutatis mutandis.
It would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to have modified the method of Lin by performing the recited treating step because Liou because Liou teaches that such a post treatment prior to the deposition of other films improves film quality of the aluminum oxide film, and AuBachon discloses that a microwave plasma is suitable for such purposes.
Furthermore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to have modified the method of Lin in view of Liou by repeating of one or more operations of the method to deposit silicon nitride film to a predetermined thickness and having a microwave plasma source by employing a PEALD process because AuBachon teaches that such processes allows for the deposition of continuous and conformal films that uniformly covers exposed surfaces, especially for semiconductor substrates having recesses or trenches that require gapfill.
Conclusion
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/JOSE I HERNANDEZ-KENNEY/
Primary Examiner
Art Unit 1717
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