DETAILED ACTION
In the amendment filed on November 5, 2025, claims 1, 8 –9, 13, 20 are pending. Claims 1, 13, 20 have been amended and claims 2 – 7, 10 – 12, 14 – 19 have been canceled.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office 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 § 103
The rejections of the claims under 35 USC § 103 in the previous Office Action are withdrawn due to Applicant amendment.
Claims 1, 9, 20 are newly rejected, as necessitated by amendment, under 35 U.S.C. 103 as being unpatentable over Hashimoto et al. US 2017/0025271 A1 (hereafter “Hashimoto”) in view of Sims et al. US 9865455 B1 (hereafter “Sims”), Akae et al. US 2011/0318937 A1 (hereinafter “Akae”).
Regarding claim 1:
Hashimoto is directed to method of manufacturing a semiconductor device, a
substrate processing apparatus, and a recording medium (Abstract; [0002] – [0003]). Part of their method of manufacturing includes a process of depositing films (Abstract; [0003], [0005]). As depicted in Fig. 5, Hashimoto discloses an embodiment of their method comprises:
forming an intermediate layer [seed layer under the broadest reasonable interpretation] of SiCN onto a stack of SiN and SiOCN layers and wafer [collectively a substrate] ([0149]) by performing a deposition cycle comprising ([0150] referencing Fig. 4 and [0146] – [0148]):
supplying a pulse of a precursor gas of HCDS (i.e. hexachlorodisilane1, identified as HCD on [0015] of instant specification) to the SiN layer,
supplying a pulse of TEA (tetraethyl amine) as an N-containing gas and C-containing gas, and
repeating the supplying of the pulses of the precursor gas and the ammonia for a number of cycles; and
forming a second film of SiN directly onto the SiCN intermediate layer comprising ([0149], [0151] referencing Fig. 4 and [0146] – [0148]):
supplying a pulse of a precursor gas of HCDS to the SiN layer,
supplying a pulse of NH3 as an N-containing gas, and
repeating the supplying of the pulses of the precursor gas and the NH3 for a number of cycles [meeting claims 4, 5].
The processes are performed at a desired temperature, e.g. 250°C to 700°C ([0065], [0070] – [0071]). Furthermore, the process cycles deposit atomic layers. While Hashimoto does not expressly disclose that their recited processes are thermal atomic layer deposition processes, one of ordinary skill in the art would have recognized that the disclosed steps, the use of thermal energy by heightened temperatures, and deposition of atomic layers implies thermal atomic layer deposition2. The SiCN and SiN films are used as etching stoppers for etching processes ([0003], [0155]).
Hashimoto does not expressly teach:
the steps of forming a SiN protective layer directly on the SiCN seed layer by a thermal ALD technique using HCD gas;
the step of forming a SiN bulk layer on the SiN protective layer by a plasma enhanced ALD technique, wherein DCS gas is supplied;
that a thickness of the SiN protective layer is 2nm or more and 3nm or less;
that the thickness of the SiN protective layer is less than a thickness of the SiN bulk layer;
that the number of cycles of the thermal ALD process in the forming of the SiN protective layer is smaller than a number of cycles of the plasma enhanced ALD process in the forming of the SiN bulk layer; and
that the forming the SiCN seed layer includes the steps of supplying C2H4 gas and NH3 to the substrate
With regards to teach the steps of forming a SiN protective layer directly on the SiCN seed layer by a thermal ALD, and forming a SiN bulk layer on the SiN protective layer by a plasma enhanced ALD:
Sims is directed to methods and apparatus for depositing a nitride film using one or more plasma-enhanced atomic layer deposition (PEALD) cycles and one or more thermal atomic layer deposition cycles (ALD) in a single reactor (Abstract). Sims discloses that forming etch-resistant SiN films under typical thermal budget constraints is difficult (col 1 lines 30 – 41).
Sims further discloses that generally, PEALD processes can deposit low wet etch resistance (WER) and highly conformal SiN films, but with a tradeoff of limiting the amount of silicon that would be incorporated in the silicon nitride film and thus affects properties such as WER (col 7 lines 10 – 45). Thermal ALD cycles enable greater tuning of material properties such as WER, but can strain the overall thermal budget of a semiconductor manufacturing process (col 8 lines 29 – 50). In an embodiment of their method as depicted in a variation of Figure 5, Sims discloses a process comprising: first applying one or more thermal ALD cycles onto substrates to deposit one or more SiN layers [protective layers]; and then secondly applying one or more PEALD cycles to deposit one or more SiN layers [bulk layer] (col 13 lines 44 – 65, col 10 lines 5 – 18, col 10 lines 48 – 60).
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 Hashimoto by dividing their SiN deposition step (which is directly deposited onto the seed layer) into a forming a SiN protective layer on the SiCN seed layer by a thermal ALD, and a step of forming a SiN bulk layer on the SiN protective layer by a PEALD because Sims teaches that utilizing both forms of ALD combines the benefits of each mode, particularly as thermal ALD has increased etch resistance while PEALD allows rapid formation of SiN without significant increase in a thermal budget of a semiconductor manufacturing process.
With regards to the forming of the SiN protective layer including the step of supplying HCD gas; and the forming of the SiN bulk layer including supplying DCS gas.
Hashimoto discloses that the precursor used in the forming of the disclosed SiN layer may be DCS or HCD ([0031], [0082]).
Similarly, Sims mirrors Hashimoto in disclosing that the precursor used for forming silicon-containing and nitride-containing films may be inter alia DCS, HCD or a mixture thereof (col 11 lines 20 – 60).
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 Hashimoto in view of Sims by supplying a combined gas of DCS and HCD as a precursor for forming both the SiN protective layer and SiN bulk layer, thus including the supplying of gases because both Hashimoto and Sims teach that both gases are suitable for forming SiN films by thermal ALD and PEALD for the same purpose through the same means. Outside a showing of unexpected results, a prima facie case of obviousness exists to combine the use of two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose. In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980).
Alternatively, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to have individually substituted the supplying of HCD gas for DCS gas as a simple substitution; as taught by Hashimoto and Sims, the use of DCS and HCD are known to be suitable for the purpose of precursors for the formation by atomic layer deposition techniques of films comprising silicon and nitrogen. The courts have held that the selection of a known material/device/product based for its intended use supports a prima facie case of obviousness. Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945), Ryco, Inc. v. Ag-Bag Corp., 857 F.2d 1418, 8 USPQ2d 1323 (Fed. Cir. 1988).
With regards to a thickness of the SiN protective layer is 2nm or more and 3nm or less, and that the thickness of the SiN protective layer is less than a thickness of the SiN bulk layer:
Sims does disclose that the thickness of a given deposited layer is a function of the dose time of precursors, exposure times of the operations and the number of cycles that the deposition steps are repeated (col 6 lines 25 – 40, col 16 lines 30 – 50). Sims further discloses that the sequential and repeated performance of PEALD and thermal ALD cycles allow for fine-tuning of properties of the resultant silicon nitride film (col 9 lines 5 – 25). Furthermore, the number of cycles performed respectively of PEALD and thermal ALD influence the concentration ratio of the overall silicon nitride film, the resultant refractive index of the film, density and wet/dry etch rates (col 16 lines 50 – 65); which enables the fine tuning of the resultant silicon nitride film.
Therefore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to have further modified the method to deposit an optimal number of cycles, and in turn respective thicknesses of the film from thermal ALD [protective layer] and PEALD [protective layer] within the claimed ranges as a matter of routine experimentation to arrive at desired final silicon nitride properties such as optimal refractive index, density and/or etch rates. Discovery of optimum value of result effective variable in known process is ordinarily within skill of art. In re Boesch, CCPA 1980, 617 F.2d 272, 205 USPQ215.
With regards to the number of cycles of the thermal ALD process in the forming of the SiN protective layer is smaller than a number of cycles of the plasma enhanced ALD process in the forming of the SiN bulk layer:
Sims discloses that atomic layer deposition processes operate by the repetition of deposition steps into cycles, wherein each cycle results in a single thin layer of material on the order of 0.1 angstroms to 0.5 angstroms per cycle in the context of Sim’s process (col 1 lines 5 – 30, col 4 line 55 – col 5 line 2). One of ordinary skill in the art would then readily recognize that that there is a direct proportionality between the final thickness of a given layer and the number of deposition cycles that were performed to create the given layer.
Therefore, in the routine experimentation of determining the optimal thickness of SiN film produced by thermal ALD and optimal thickness of SiN film produced by plasma-enhanced ALD, any optimal solution that leads to the thermally produced SiN film having less thickness than the plasma-enhanced ALD film would be expected to have the number of deposition cycles of thermal ALD be less than the number of cycles of plasma-enhanced ALD for their respective films.
With regards to the forming the SiCN seed layer including the steps of supplying C2H4 gas and NH3 to the substrate:
Akae is directed to inter alia a method of manufacturing a semiconductor device which includes forming a thin film on a substrate (Abstract). Similar to Hashimoto, Akae discloses in an embodiment a thermal ALD process of forming an SiCN film comprising (Fig. 3; [0050] – [0053]):
providing a pulse of a chlorosilane based precursor gas, e.g. HCD
providing a pulse of ammonia; and
providing a pulse of a hydrocarbon-based gas, e.g. propylene or ethylene (C2H4) ([0073]).
By adjusting the processing conditions and gas concentrations, the composition and ratio of each respective element in the SiCN film can be tailored ([0088]).
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 Hashimoto in view of Sims by supplying distinctly a nitrogen-containing gas (NH3) and distinctly a carbon-containing gas (C2H4) in the thermal ALD process of forming the SiCN film because Akae teaches that such supply steps allow for tailored control of the resultant composition ratio of the final SiCN film formed.
Regarding claim 9:
Hashimoto discloses that wafers to be processed remain in a heated state and under vacuum during the later described film forming processes ([0065]), thus the processes are performed in the same processing chamber. Furthermore, Sims discloses that the thermal ALD process and the PEALD process occurs in the same chamber (col 2 lines 60 – 65, col 16 lines 10 – 31).
Regarding claim 20:
As exemplified by Figures 1 and 2, Hashimoto discloses a processing apparatus comprising:
a reaction tube 203 containing a processing chamber 201 that is configured to accommodate a wafer boat 217 with substrate wafers loaded [configured to contain substrates] (Fig. 1; [0023] – [0024]);
gas supply pipes 232a and 232b through mass flow controllers and vales to nozzles 249a, 249b that are installed within the processing chamber [configured to supply gas to processing chamber] ([0025] – [0026]);
an exhaust pipe connecting the processing chamber 201 to a vacuum pump 246 serving as a vacuum exhaust device for the process chamber ([0044]); and
a controller containing a control program for controlling operations of the substrate processing apparatus, including the operations of Hashimoto discussed above in the rejection of claim 1 [configured to control gas supply and exhaust for forming a SiCN seed layer on a substrate by thermal ALD, control gas supply and exhaust for forming a SiN layer] ([0048] – [0050]).
Hashimoto does not expressly teach that the controller is configured to:
control the gas supply and the exhaust to perform forming a SiN protective layer on the SiCN seed layer by thermal ALD with the recited C2H4 and NH3 gases; and
forming a SiN bulk layer on the SiN protective layer by PEALD with the respective film thicknesses wherein the number of cycles of thermal ALD processing is less than the number of cycles of PEALD processing with the recited supplied gases.
Sims discloses that their process steps, as discussed above in the rejection of claim 1, may be controlled by one or more system controllers 750 that control pressure conditions within the processing chamber and are capable of performing the operations for thermal ALD and PEALD (Fig. 7A; col 18 lines 15 – 50).
It would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to have modified the controller of Hashimoto by further configuring the controller to allow gas and exhaust control for dividing their SiN deposition step into a forming a SiN protective layer on the SiCN seed layer by a thermal ALD, and a step of forming a SiN bulk layer on the SiN protective layer by a PEALD because Sims teaches that utilizing both forms of ALD combines the benefits of each mode, particularly as thermal ALD has increased etch resistance while PEALD allows rapid formation of SiN without significant increase in a thermal budget of a semiconductor manufacturing process.
Further, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to have further modified the controller configuration enable a step of depositing an optimal number of cycles, and in turn respective thicknesses of the film from thermal ALD [protective layer] and PEALD [protective layer] within the claimed ranges as a matter of routine experimentation to arrive at desired final silicon nitride properties such as optimal refractive index, density and/or etch rates. Discovery of optimum value of result effective variable in known process is ordinarily within skill of art. In re Boesch, CCPA 1980, 617 F.2d 272, 205 USPQ215.
Further, in the routine experimentation of determining the optimal thickness of SiN film produced by thermal ALD and optimal thickness of SiN film produced by plasma-enhanced ALD, any optimal solution that leads to the thermally produced SiN film having less thickness than the plasma-enhanced ALD film would be expected to have the number of deposition cycles of thermal ALD be less than the number of cycles of plasma-enhanced ALD for their respective films.
Finally, 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 Hashimoto in view of Sims by configuring the controller to supply distinctly a nitrogen-containing gas (NH3) and distinctly a carbon-containing gas (C2H4) in the thermal ALD process of forming the SiCN film because Akae teaches that such supply steps allow for tailored control of the resultant composition ratio of the final SiCN film formed.
Claim 8, 13 are newly rejected, necessitated by amendment, rejected under 35 U.S.C. 103 as being unpatentable over Hashimoto in view of Sims and Akae as applied to claims 1, 4, 5, 6, 7, 9, 14, 20 above, and further in view of Ueda et al. US 2019/0333753 A1 (hereafter “Ueda”).
Regarding claim 8:
Hashimoto in view of Sims does not expressly teach that the step of forming the SiN bulk layer further includes exposing the substrate to a plasma generated from a H2 gas.
Ueda is directed to methods of forming silicon nitride films by inter alia PEALD with hydrogen plasma and nitrogen plasma treating steps (Abstract; [0001]). As depicted in Fig. 2, Ueda discloses a method of forming and in-situ treating a SiN film comprising ():
contacting a substrate with a silicon precursor and nitrogen reactant to deposit a part of the silicon nitride film (step 230, [0084], [0087]);
performing a first hydrogen plasma treatment of the substrate with deposited films (step 210, [0085], [0089], [0093] – [0095]); and
repeating the previous steps.
The hydrogen plasma can be generated from the flow of hydrogen gas ([0093]). Such a plasma treatment helps improve side-wall conformality on patterned substrates, better step coverage ([0002], [0005] – [0006]), and also decreased wet etch rates ([0023]).
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 Hashimoto in view of Sims and Akae by including the substep of exposing the substrate to a plasma generated from a H2 gas within the step of forming the SiN bulk layer because Ueda teaches that such a treatment improves side-wall conformality, step coverage and wet etch rates of the resultant SiN film.
Regarding claim 13:
Hashimoto discloses that wafers to be processed remain in a heated state and under vacuum during the later described film forming processes ([0065]), thus the processes are performed in the same processing chamber. Furthermore, Sims discloses that the thermal ALD process and the PEALD process occurs in the same chamber (col 2 lines 60 – 65, col 16 lines 10 – 31).
Response to Arguments
Applicant's arguments filed November 5, 2025 have been fully considered but they are not persuasive.
Applicant’s principal arguments are:
a.) None of the references describes or suggests the specific combination of the gases in each of the forming processes, nor do they distinguish and specify the use of the HCD gas in the thermal ALD and the DCS gas in the plasma enhanced ALD as the silicon-containing gases, nor do they mention the use of the NH3 gas throughout the processes of the forming of the SiCN seed layer, the forming of the SiN protective layer, and the forming of the SiN bulk layer.
b.) The unexpected results of forming a higher-quality SiN film with greater thickness while sufficiently reducing damage to the SiCN seed layer, thereby improving the overall film quality, as described in paragraphs [0046] and [0061] of the specification of the present application, occur over the entire claimed range.
In response to the applicant's arguments, please consider the following comments.
a.) New grounds of rejection, necessitated by amendment, are set forth in the rejections of the claims under 35 USC §103 as discussed above. Contrary to Applicant’s argument; Hashimoto, Sims and Akae disclose the supplying of the recited precursor and reactant gases as discussed above. With regards to a lack of suggestion to the specific combination of gases in each of the forming processes, the Examiner notes that the principle manipulative acts generically recited in the claim (e.g. “forming a SiCN seed layer…”) include the supplying of the recited gases to the substrate. Under the broadest reasonable interpretation consistent with the specification, “including” is synonymous with “comprising”. Thus, the claims allow e.g. for more than one precursor/reactant gas to be supplied in the respective forming acts, so long as the required act of supplying the recited gas within the forming acts are taught by the prior art of record.
b.) Applicant’s reply appears to be an argument that the claimed invention – particularly the thickness of the thermal ALD-deposited SiN protective layer be 2nm to 3nm and the thickness of the thermal ALD-deposited SiN protective layer being less than the thickness of the PEALD-deposited SiN bulk layer – demonstrates unexpected results. Applicant’s reply references paragraphs [0046] and [0061] of the instant specification as evidence of unexpected results. However, the statement is a conclusory statement that does not provide or point to data and other evidence to support the professed advantage, particularly when the statement states that “can possibly form a higher-quality SiN film with greater thickness while sufficiently reducing damage to a SiCN seed layer”. The evidence relied upon should establish "that the differences in results are in fact unexpected and unobvious and of both statistical and practical significance." Ex parte Gelles, 22 USPQ2d 1318, 1319 (Bd. Pat. App. & Inter. 1992). Furthermore, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
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 extension fee 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 date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOSE I HERNANDEZ-KENNEY whose telephone number is (571)270-5979. The examiner can normally be reached M-F 6:30-3:30.
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/JOSE I HERNANDEZ-KENNEY/
Primary Examiner
Art Unit 1717
1 As evidenced by Ereztech.”Hexachlorodisilane” (2021). Retrieved from https://ereztech.com/
2 "[I]n considering the disclosure of a reference, it is proper to take into account not only specific teachings of the reference but also the inferences which one skilled in the art would reasonably be expected to draw therefrom." In re Preda, 401 F.2d 825, 826, 159 USPQ 342, 344 (CCPA 1968).