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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 04/13/2026 has been entered.
Status of the Claims
This is a non-final office action in response to the applicant’s arguments and remarks filed on 04/13/2026. Claims 1-9 and 11-20 are pending in the current office action. Claims 1, 5, 7, 12, 14, 18, and 20 have been amended by the applicant.
Status of the Rejection
All 35 U.S.C. § 112(b) rejections from the previous office action are withdrawn in view of the Applicant’s amendment.
Some 35 U.S.C. § 103 rejections from the previous office action are substantially maintained and modified only in response to the amendments to the claims.
Some 35 U.S.C. § 103 rejections from the previous office action are withdrawn in view of the Applicant’s amendment.
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.
Claims 12-17 are rejected under 35 U.S.C. 103 as being unpatentable over Ishikawa et al. (US 2020/0321209 A1) in view of Kaneko (US-20210265158-A1) and Durand et al. (US-20210050212-A1).
Regarding Claim 12, Ishikawa teaches a method of fabricating a layer structure ([abstract] method for fabricating a layer structure), comprising:
providing a substrate in a reaction chamber, wherein the substrate comprises on an upper surface a trench with a top surface, a bottom surface, and sidewalls ([abstract] substrate with a trench that contains an upper surface, equivalent to claim “top surface”, a bottom surface, and sidewalls is provided. Paragraph [0080] method includes processing substrate in a reaction chamber);
forming a film comprising SiN on the upper surface of the substrate (Paragraph [0035] a film containing an Si-N bond is formed on an upper surface of the substrate) using a cyclic plasma deposition process, wherein the cyclic plasma deposition process includes providing a flow of a carrier gas comprising argon to the reaction chamber and using the carrier gas to provide a precursor to the reaction chamber (Paragraph [0006] plasma-enhanced deposition processes are used. Paragraph [0077] precursor is supplied using a carrier gas. Paragraph [0102] and Table 10, a deposition process using plasma, and containing multiple cycles is used, and includes the use of a carrier gas that comprises argon and a precursor); and
after the forming of the film, removing with etching at least a portion of the film on at least one of the sidewalls, the top surface, and the bottom surface, wherein the etching has a first rate for the portion of the film on the sidewalls, a second rate for the portion of the film on the bottom surface, and a third rate for the portion of the film on the top surface and wherein the first, second, and third rates for the etching differ (Paragraph [0102] and Figure 17, after film formation wet etching is conducted. Figure 17 shows that the etch rate of the sidewalls, the etch rate of the bottom surface and the etch rate of the top surface are different such that a thicker layer of SiN film remains on the top surface after etch than remains on the bottom surface and none of the SiN film remains on the sidewalls),
wherein a plasma used in the cyclic plasma deposition process is generated remotely and provided to the reaction chamber (Paragraphs [0056-0058] Figure 6 a process of deposition is taught that can include the use of a remote plasma deposition).
Ishikawa fails to teach that the carrier gas comprises argon and nitrogen that are supplied at a predefined flow ratio. However, Ishikawa further teaches that during the deposition process a dilution gas comprising nitrogen and argon is supplied and teaches flow rates (Paragraph [0102] and Table 10). Ishikawa further teaches a flow rate for the argon of the carrier gas and for both the argon and the nitrogen of the dilution gas (Paragraph [0102] and Table 10). Ishikawa fails to teach that the carrier gas is flowed to a precursor reservoir and that the carrier gas provides the precursor from the precursor reservoir to the reaction chamber.
Kaneko teaches methods related to forming layers and structures for electronic devices (Paragraph [0002]). Kaneko teaches supplying inert gases to the reaction chamber at the same time as providing a precursor to the reaction chamber (Paragraph [0044]). Kaneko teaches that the inert gas (also called an carrier gas) can be supplied to a precursor reservoir and then a gas flow from the precursor reservoir to the reaction chamber can include the inert gas and the precursor gas (Paragraph [0065]). Kaneko teaches that the inert gas can be a mixture of argon and nitrogen gas (Paragraph [0029]).
It would have been obvious to one of ordinary skill in the art to have modified the method of Ishikawa such that the dilution gas and the carrier gas were supplied at set flow rates such that they comprised a predefined flow ratio. It would have been further obvious to supply the dilution and carrier gases together to the precursor reservoir, and to then have a gas flow from the precursor reservoir to the reaction chamber that comprised the dilution gas (which would be equivalent to one claimed carrier gas, and would be specifically nitrogen), the carrier gas (would be equivalent to the other claimed carrier gas, and would be specifically argon) and a precursor gas, as taught by Kaneko.
This modification would have been obvious because it would have been the combination of prior art elements according to known methods to yield predictable results. Providing the carrier gas and dilution gas together to the precursor reservoir and then using the carrier gas and dilution gas to supply the precursor gas to the reaction chamber would have had the predictable result of providing a suitable gas mixture for the deposition process. See MPEP 2143(I)(A).
Additionally, while Ishikawa does not explicitly state the etch rates, modified Ishikawa teaches that the film to be etched is formed in a method identical to the method claimed in Claim 12. The etch rate of a film is an inherent property of that film: any film created with an identical method, on an identical structure, that has the etch rate measured with the same method will be found to have the same etch rate. Therefore, the etch rates on the sidewalls, top surface, and bottom surface of the film as taught by Ishikawa will vary in the same way as claimed.
Modified Ishikawa as outlined above fails to teach to teach controlling the predefined ratio of the argon to the nitrogen to obtain the film having a desired film etch rate.
Ishikawa teaches that the changes to the density of the deposited film cause changes in the wet etch rate of the deposited film (Paragraph [0043] changes in the process, which can result in the formation of hydrogen bonds formed with nitrogen or silicon, will affect the density of the deposited film which will affect the wet etch rate of that film).
Durand teaches methods related to depositing films (Paragraph [0002]). Durand teaches methods that can deposit silicon nitride (Paragraphs [0051-0053]). Durand teaches that the deposition process includes generating a plasma and flowing a precursor-containing gas that can also include other gases (Paragraphs [0057-0060]). Durand teaches that the precursor-containing gas mixture can include an inert gas, that can be argon (Paragraph [0063]) and that including argon can affect the density of the deposited film (Paragraph [0061]). Durand teaches that other processing gases can be added to the precursor-containing gas mix to modify the properties of the deposited film, providing the specific examples that N2 can be included to control the density and deposition rate of the deposited film, and that reactive gases, including H2, NH3, and N2, can be provided to control the ratio of hydrogen that is deposited which will affect the properties of the layer deposited (Paragraph [0063]).
It would have been obvious to one of ordinary skill in the art to have modified the method of modified Ishikawa by controlling the flow rates, and thereby the ratio of those flow rates, of argon and the nitrogen. This would have been obvious because Durand teaches that the flow rate of nitrogen gas, and the flow rate of argon gas, can each control the density of the deposited film and the flow rate of nitrogen gas in relation to hydrogen containing gases can also control the density and properties of the deposited film, and Ishikawa teaches that the density of the deposited film affects the wet etch rate of that film. Therefore, in view of the teachings outlined above, one of ordinary skill in the art would have understood that the flow rates of argon and nitrogen would affect the wet etch rate of the deposited film and would have been motivated to control these flow rates individually and thereby the ratio of those flow rates, in order to create a film with the desired wet etch rates within the method of modified Ishikawa.
This modification would have been obvious because it would have been the combination of prior art elements according to known methods to yield predictable results. Controlling the flow rates of argon and nitrogen would have had the predictable result of affecting the density of the deposited film, which would have had the predictable result of affecting the wet etch rate of that film. See MPEP 2143(I)(A).
Regarding Claim 13, modified Ishikawa teaches the method of claim 12 as outlined above. Ishikawa further teaches wherein the cyclic plasma deposition process comprises PEALD (Paragraph [0006] deposition can use a PEALD process. Paragraph [0102], Example 8 uses plasma and is a PEALD process).
Regarding Claim 14, modified Ishikawa teaches the method of claim 12, as outlined above. Ishikawa further teaches wherein a cycle of the cyclic plasma deposition process includes contacting the upper surface of the substrate with the precursor selected from the group consisting of H2SiCl2, hexachlorodisilane, trichlorosilane (HSiCl3), and chlorosilane (H3SiCl) (Paragraph [0102] and Table 10, dichlorodisilane (which is the same as H2SiCl2) is used).
Regarding Claim 15, modified Ishikawa teaches the method of claim 12, as outlined above. Ishikawa further teaches wherein the first rate for the etching for the portion of the film on the sidewalls is greater than the second rate for the etching for the portion of the film on the bottom surface and wherein the second rate for the etching for the portion of the film on the bottom surface is greater than the third rate for the etching for the portion of the film on the top surface (Paragraph [0102] and Figure 17 which shows that the etch rate of the sidewalls is the greater than the etch rate of the bottom surface such that no SiN film remain on the sidewalls after etching while some SiN film remains on the bottom surface, and that the etch rate of the bottom surface is greater than the etch rate of the top surface such that a thicker layer of SiN film remains on the top surface after etch than remains on the bottom surface).
Additionally, while Ishikawa does not explicitly state these etch rates, modified Ishikawa teaches that the film to be etched is formed in a method identical to the method claimed in Claim 12. The etch rate of a film is an inherent property of that film: any film created with an identical method, on an identical structure, that has the etch rate measured with the same method will be found to have the same etch rate. Therefore, the etch rates on the sidewalls, top surface, and bottom surface of the film as taught by modified Ishikawa will have the same relationship relative relationship to each other as claimed.
Regarding Claim 16, modified Ishikawa teaches the method according to claim 12, as outlined above.
Ishikawa fails to explicitly teach that the predefined ratio of argon to nitrogen is in the range of 0 to 4.
However, Ishikawa teaches the generic acceptable ranges for processing conditions which include a flow rate of 100 – 5000 sccm for the taught carrier gas, equivalent to the claimed first carrier gas, and a flow rate of 0 – 10000 sccm for the taught dilution gas, equivalent to the claimed second carrier gas (Paragraph [0068] and Table 1 provides gas flow rate ranges for deposition process). The taught carrier gas can comprise argon and the taught dilution gas can comprise nitrogen (Paragraph [0068] and Table 1, argon listed as suitable carrier gas and nitrogen listed as suitable dilution gas).
It would have been obvious to one of ordinary skill in the art to have selected and utilized in the process both argon and nitrogen, and a flow rate for the carrier gas within the disclosed range of 100 – 5000 sccm and a flow rate for the dilution gas within the disclosed range of 0 – 10000 sccm, such that the ratio of argon to nitrogen would have been 0 to 4 as claimed. It has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art. See MPEP 2144.05 (I).
Regarding Claim 17, modified Ishikawa teaches the method according to claim 12, as outlined above. Ishikawa further teaches wherein the predefined flow ratio is greater than 4 (Paragraph [0102] and Table 10, in Example 8 the flow rate of argon in the taught carrier gas is 1000 sccm and the flow rate of argon in the taught dilution gas is 2000 sccm and the flow rate of nitrogen in the taught dilution gas is 500 sccm. As outlined above in regards to claim 12, both the taught carrier gas and taught dilution gas comprise the claimed carrier gas and therefore the ratio is 6 ((1000+2000)/500=6)).
Allowable Subject Matter
Claims 1-9, 11, and 18-20 are allowed.
The following is a statement of reasons for the indication of allowable subject matter: The prior art does not disclose nor render obvious all of the cumulative limitations of independent claims 1 and 18 with particular attention to the limitation “removing with etching the dielectric film from the sidewalls and the bottom surface while the dielectric film on the top surface remains”.
The closest prior art of record is considered to be Ishikawa et al. (US 2020/0321209 A1).
Ishikawa teaches a method of fabricating a layer structure ([abstract] method for fabricating a layer structure), comprising: providing a substrate in a reaction chamber, wherein the substrate comprises on an upper surface a trench with a top surface, a bottom surface, and sidewalls ([abstract] substrate with a trench that contains an upper surface, equivalent to claim “top surface”, a bottom surface, and sidewalls is provided. Paragraph [0080] method includes processing substrate in a reaction chamber); providing a carrier gas flow, (Paragraph [0077] precursor is supplied using a carrier gas); providing a gas flow to the reaction chamber the gas flow comprising the first carrier gas and a precursor (Paragraph [0077] precursor is supplied using a carrier gas) and forming a dielectric film containing a Si-N bond on the upper surface of the substrate (Paragraph [0035] a dielectric film containing a Si-N bond is formed on an upper surface) and after the forming of the dielectric film, removing with etching at least a portion of the dielectric film on at least one of the sidewalls, the top surface, and the bottom surface, wherein the etching has a first rate for the portion of the dielectric film on the sidewalls, a second rate for the portion of the dielectric film on the bottom surface, and a third rate for the portion of the dielectric film on the top surface (Paragraph [0035] wet etching removes a portion of film from top, bottom, and sidewall, therefore the removal of each has an etch rate). Ishikawa further teaches that during the process a dilution gas is supplied to the reaction chamber (Paragraph [0080] a dilution gas is introduced to reaction chamber). Ishikawa teaches that the dilution gas may be N2 and the taught carrier gas can be Ar (Paragraph [0068] Table 1, carrier gas Ar is continuously supplied, dilution gas N2 is continuously supplied). However, Ishikawa teaches that the dilution gas and the precursor/carrier gas are supplied to the chamber separately and therefore fails to teach wherein the carrier gas flow is provided to a precursor reservoir and that a gas flow from the precursor reservoir to the reaction chamber comprises a first carrier gas, a second carrier gas, and a precursor.
Ishikawa fails to teach a step of removing with etching the dielectric film from the sidewalls and the bottom surface while the dielectric film on the top surface remains.
The claims are therefore considered to be patentably distinguished from the prior art of record. The prior art of record, whether taken alone or in combination, does not disclose nor render obvious the cumulative limitations of claims 1 and 18. Claims 2-9, 11, and 19-20 are dependent from or otherwise include the limitations of claims 1 and 18 and are allowable for the same reasons as above.
Response to Arguments
Applicant's arguments/amendments filed 04/13/2026 with respect to rejections of Claims 1 and 18, in view of the amendments, have been fully considered and are persuasive. As noted above, Claims 1 and 18, and all claims dependent upon those independent claims have been marked as allowable.
Applicant’s arguments, see Remarks Pg. 3-4, filed 04/13/2026, with respect to the 35 U.S.C. § 103 rejection of claim 12 have been fully considered and are not persuasive.
Applicant argues that fails to teach the use of remote plasma in the deposition process.
Examiner respectfully disagrees. The cited prior art highlights particular embodiments that use a plasma excited by a voltage applied between two electrodes, however the cited prior also describes alternative embodiments. As outlined in the rejection of claim 12 above, the cited prior does that remote plasma can be used in the deposition process.
Conclusion
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/A.K.L./Examiner, Art Unit 1713 /DUY VU N DEO/Primary Examiner, Art Unit 1713
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