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 Amendment
Claims 1-16 are pending in the Amendment filed 07/06/2026.
The rejection of claims 11-13 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite is withdrawn in view of Applicant’s amendments to claims 11 and 12.
Claim 13 is objected to as being dependent upon a rejected base claim.
The prior art rejections of record are maintained. See “Response to Arguments” below.
Response to Arguments
Applicant's arguments, see “Remarks” filed 07/06/2026, have been fully considered but they are not persuasive.
Applicant argues as to the rejection over Rui:
“Regarding claim 1, the Office Action asserts that paragraph [0061] of Rui teaches removing a polymer containing sidewall film from etch features. Applicants respectfully disagree. Paragraph [0028] of the present application describes the fluoropolymer sidewall film 445 deposited on the sidewalls of etch features 440, as shown in FIG. 4. Paragraph [0061] of Rui discloses no such sidewall film within etch features. Rather, Rui discloses that polymer residues and etch by-products deposit on the substrate bevel and backside, and that photoresist may remain on the substrate front side after etching. Rui at para. [0061]. These are surface-level and bevel deposits, not a conformal fluoropolymer film on the interior walls of deep, high-aspect- ratio etch features.
“This distinction is confirmed by Rui's stated purpose: "embodiments of the invention relates to a semiconductor processing system utilized to remove polymers from a backside of a substrate in semiconductor fabrication." Rui at para. [0003]. The need Rui identifies is "to remove polymer from substrate bevel backside while maintaining the integrity of structures formed on substrate front side." Rui at para. [0010]. Rui's apparatus is specifically designed to direct reactive species toward the periphery region and bevel of the substrate. Rui at para. [0029] ("the position of the gas outlet port 150 may be positioned to be above, below, or aligned with the substrate bevel 132 to selectively clean the top, bottom, and/or edge of the substrate 110"). Nothing in Rui discloses or suggests directing reactive species into the interior of deep etch features to strip a fluoropolymer sidewall film deposited therein. Removal of a sidewall film from deep etch features is a fundamentally different technical problem from removing surface residue and photoresist from the substrate bevel and front side.” [“Remarks”, pg. 6, para. 4- pg. 7, para. 1].
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., “directing reactive species into the interior of deep etch features to strip a fluoropolymer sidewall film deposited therein”) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Moreover, Rui provides an embodiment comprising patterning silicon nitride features using fluorocarbon etching gases [para. 0060], which produces polymer residues (“During etching process, the etched materials may combine with the components of the etchant chemistry, as well as with the components of the mask layers, if any, and by-products of the etch process, thereby forming polymer residues.”) that deposit on the substrate [para. 0061]. One of ordinary skill in the art would therefore expect at least some polymer residue to form on the formed sidewall feature based on the etch chemistry and patterning process disclosed.
Applicant further argues as to the reference to Rui:
“Furthermore, Rui's own claims confirm that SiN-layer processing is outside the scope of Rui's invention. Rui's claim 14 explicitly defines the etch reactor as "configured to etch a dielectric material disposed on the substrate, wherein the dielectric material is selected from at least one of silicon oxide and silicon oxycarbide." Silicon nitride (SiN) is expressly excluded. This confirms that Rui does not contemplate the SiN-layer ONON stack context that is central to the present claims.” [“Remarks”, pg. 7, para. 2].
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., “SiN-layer ONON stack”) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Additionally, claims 1 and 14 only require an etched feature and a wafer with a stack with at least one silicon nitride containing layer, i.e., the claim does not require the silicon nitride layer have an etched feature. Here, Rui teaches that the substrate may comprise multiple layers, including silicon nitride and other materials such as a silicon oxide layer [para. 0059].
Furthermore, Applicant’s argument is not persuasive because Rui discloses an embodiment directed to silicon nitride alongside the embodiments directed towards silicon oxide and silicon oxycarbide [para. 0061]. Moreover, disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. See MPEP 2123 I & II.
Applicant further argues as to the reference to Rui:
“The Office Action acknowledges that Rui does not explicitly disclose a stripping gas comprising a hydrogen-containing gas and at least one of CO₂, CO, N2O, NO, or NO2, and asserts that such a modification would have been obvious. However, the purpose of Rui - removing photoresist and surface polymer from the front side and bevel of a substrate - is fundamentally different from the purpose of claim 1, which is to remove a fluoropolymer sidewall film from within etch features of a SiN-layer stack while preserving the integrity of the SiN layers. Because Rui's process operates in a different context, on different materials, and to achieve a different result, the Office Action has not established a motivation to modify Rui's stripping gas to arrive at the specific combination claimed. Moreover, Rui's four concrete removal embodiments - described at paragraphs [0065] through [0068] - use H₂/H₂O (for SiOC) and N2/H2 or O₂/N₂ (for SiO2). CO2, CO, N2O, NO, and NO2 are never selected in any practiced example. The skilled artisan following Rui's teachings would have no reason to depart from those practiced embodiments to arrive at the claimed combination. For at least these reasons, claim 1 is not rendered obvious by Rui.” [pg. 7, para. 3].
In response, this argument is not persuasive because Rui teaches an embodiment directed to the same purpose as that of the instant invention [para. 0060-61]—i.e., to remove polymer residues from substrate surfaces formed by etching a silicon nitride feature using a fluorocarbon etching gas—and further provides sufficient guidance to form a stripping gas comprising a hydrogen-containing gas and nitrogen containing gas (i.e., including the disclosed species N2, N2O and/or NO2) because hydrogen-containing gases and nitrogen-containing gases form highly reactive radicals to polymer residuals and etch by-products, as taught by Rui [Rui, para. 0062].
Applicant argues as the reference to Rui as applied to claim 6:
“Additionally, claim 6 recites the step of moving the wafer from the etch chamber to a stripping chamber without breaking the vacuum. This vacuum transfer step prevents the fluoropolymer sidewall films from being exposed to atmospheric humidity, which would cause erosion of the ONON stack. See Application at para. [0019]. While Rui's system includes a vacuum transfer chamber (Rui at para. [0054]), Rui's vacuum transfer is not directed at or motivated by the problem of SiN-layer degradation from humidity exposure of fluoropolymer sidewall films - a problem Rui never recognizes or addresses.” [“Remarks”, pg. 8, para. 2].
In response, Applicant's arguments fail to comply with 37 CFR 1.111(b) because they amount to a general allegation that the claims define a patentable invention without specifically pointing out how the language of the claims patentably distinguishes them from the references.
Applicant argues as to claims 2 and 7 as rejected over Rui:
“[C]laims 2 and 7 each depend on their respective independent claims and further recite that the H₂-containing gas is a forming gas comprising H₂ and N₂, wherein the forming gas is 0.1% to 4% H₂. The Office Action relies on paragraph [0067] of Rui for this limitation. Paragraph [0067] of Rui describes the gas mixture used to remove bevel and backside polymer after etching a silicon oxide (SiO₂) film - specifically a mixture of N₂ and H₂ at particular flow rates. The Office Action does not identify anything in paragraph [0067] that would establish a motivation to use this gas mixture to remove a fluoropolymer sidewall film from the interior of etch features in a silicon nitride layer. Applying Rui's SiO2-specific removal gas to an entirely different substrate type (SiN-layer ONON stack) and an entirely different removal target (interior sidewall film within deep etch features) requires an inferential leap that the Office Action has not justified.” [“Remarks”, pg. 9, para. 3].
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., “SiN-layer ONON stack”) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Moreover, Applicant’s argument is not persuasive because, since Rui does not explicitly provide an embodiment for removing the polymer residue from the silicon nitride etched wafer, one of ordinary skill in the art would employ the teachings for removing polymer residue from the silicon oxide embodiment because the silicon oxide plasma chemistry is most similar to that of the silicon nitride plasma chemistry (i.e., CHF3), [para. 0060], and therefore would form similar etch by-products.
Additionally, as to claim 2, claims 1 only requires an etched feature and a wafer with a stack with at least one silicon nitride containing layer, i.e., the claim does not require the silicon nitride layer have an etched feature. Here, Rui teaches that the substrate may comprise multiple layers, including silicon nitride and other materials such as a silicon oxide layer [para. 0059].
Applicant argues as to claim 7 as rejected over Rui:
“Furthermore, the Office Action does not establish a motivation to combine the SiO2 removal recipe of paragraph [0067] with the general photoresist removal gas list of paragraph [0062], as these relate to different process embodiments serving different purposes within Rui.” [“Remarks”, pg. 10, para. 1].
In response, this argument is not persuasive because para. 0062 is applicable to each of the removal recipes [para. 0065, 0067] and photoresist removal recipes [para. 0066, 0068]. Moreover, para. 0062 teaches the result-effective nature of each of the disclosed gas species/radical species for the purpose of removing polymer residuals and etch byproducts.
Applicant argues to the combination of Rui and Cheung:
“The Office Action does not establish a sufficient motivation to combine Rui and Cheung. Cheung is directed to stripping photoresist and etch-related residues from low-k dielectric (carbon-doped oxide, CDO) materials using a hydrogen-based plasma with a weak oxidizing agent (CO2) and a fluorine-containing compound (NF₃). Cheung at Abstract, para. [0007]. Cheung's temperature constraint - below 200°C, and preferably below 90°C - is specifically motivated by the need to prevent thermal damage to low-k CDO films. Cheung at paras. [0036], [0044]. This concern has no bearing on Applicants' SiN-layer ONON stack process, where the materials present, the damage mechanisms at issue, and the process objectives are entirely different.
“Furthermore, Cheung's process employs NF₃, a halogen-containing gas, as described at paragraph [0029] of Cheung. The present application discloses a halogen-free stripping gas. See Application at para. [0020] ("stripping gas in such embodiments is fluorine and halogen free"); see also claim 5 and claim 10. The inclusion of a halogen-containing component in Cheung's process makes Cheung's teachings inapposite to the claimed halogen-free chemistry and further undermines any motivation to import Cheung's temperature range into the process of Rui.” [“Remarks”, pg. 10, para. 3-4].
In response, this argument is not persuasive because the motivation to relied upon to combine Rui with Cheung, i.e., to prevent damage to low-k dielectric films during the stripping/residue removal process, is proper because Rui teaches including low-k dielectric layers within the materials formed on the substrate [para. 0055].
All other arguments presented within Applicant’s “Remarks” are believed to be duplicative or are otherwise addressed by the responses above. For the foregoing reasons, the rejections of record are maintained.
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.
Claims 1-10, 12, and 14-16 are rejected under 35 U.S.C. 103 as being unpatentable over Rui et al. (US 20090277874 A1).
As to claim 1, Rui discloses a method for stripping a polymer containing sidewall film from etch features [para. 0061] and a polymer containing deposition layer from a backside of a bevel of a wafer [para. 0061] with a stack with at least one silicon nitride containing layer [para. 0059, “material layer that may be disposed on the substrate include a dielectric layer, such as a SiOC, SiO.sub.2 or a SiCN, SiC or SiN layer”, “the substrate may have multiple layers, e.g., a film stack, utilized to form different patterns and/or features”], comprising:
forming a plasma from a stripping gas [para. 0062-63; para. 0065; para. 0067], the stripping gas comprising:
a hydrogen (H2) containing gas [Id.]; and
at least one of CO2, CO, N2O, NO, or NO2 [Id.; Obvious to include, see below],
wherein the plasma creates radicals from the stripping gas [Id.]; and
exposing the wafer to the radicals, wherein the radicals remove the polymer containing sidewall film and the polymer containing deposition layer [para. 0062, “remove the polymer residuals, photoresist layer, if any, and etch by-products from the substrate 110”].
Rui fails to explicitly disclose an embodiment of the stripping gas comprising a hydrogen containing gas and at least one of CO2, CO, N2O, NO, or NO2.
However, Rui discloses the combination hydrogen-containing gas and nitrogen containing gases form highly reactive radicals to remove polymer residuals and etch by-products from the substrate [para. 0062], as follows in pertinent part:
“The remote plasma source 154 of the processing chamber 100 supplied active reactant, such as hydrogen and/or nitrogen containing gases, to the processing chamber 100 to assist removal of polymer residuals, photoresist layer and etch by-products from the substrate 110. As hydrogen species (H.sup.-, H*, H.sup.+), hydroxyl radical (--OH), nitrogen radical, and/or N--H radical are highly reactive radicals to polymers, upon supplied dissociated hydrogen, nitrogen or hydroxyl species into the processing chamber 100, the reactive species are actively reacted with the polymers, forming volatile compounds, readily pumping and outgassing the volatile compounds out of the processing chamber 100. The gas mixture may include an oxygen-containing gas, such as O.sub.2, O.sub.3, water vapor (H.sub.2O), a hydrogen-containing gas, such as H.sub.2, water vapor (H.sub.2O), NH.sub.3, nitrogen containing gas, such as N.sub.2, N.sub.2O, NH.sub.3, NO.sub.2, and the like, or an inert gas, such as a nitrogen gas (N.sub.2), argon (Ar), helium (He), and the like.” [para. 0062].
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the polymer removal gas mixture, of Rui, to include hydrogen (H2) and N.sub.2, and N.sub.2O, and/or NO.sub.2, because hydrogen-containing gas and nitrogen containing gases form highly reactive radicals to remove polymer residuals and etch by-products from the substrate, as taught by Rui [para. 0062].
As to claim 2, modified Rui discloses the method, as recited in claim 1, wherein the H2 containing gas is a forming gas comprising:
H2 [para. 0067]; and
N2 [para. 0067],
wherein the forming gas is 0.1% to 4% H2 [para. 0067, “H.sub.2 is supplied at a flow rate between about 50 sccm and about 500 sccm”, “N.sub.2 gas is supplied at a flow rate between about 200 sccm and about 2000 sccm”, which converts to about 2.4% to 71% H2, overlapping and supporting a prima facie case of obviousness over the claimed range].
As to claim 3, modified Rui discloses the method, as recited in claim 2, wherein the stripping gas consists essentially of the forming gas [para. 0067] and at least one of CO2, CO, N2O, NO, or NO2 [para. 0062, “N2O… NO2”].
Here, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the polymer removal gas mixture (i.e., H2 and N2), of Rui [para. 0067], to further include N2O or NO2, of Rui [para. 0062] in order to form hydroxyl radicals which further aid in removing etch by-products from the substrate [para. 0062].
As to claim 4, modified Rui discloses the method, as recited in claim 2, wherein the stripping gas consists essentially of the forming gas, at least one inert gas [para. 0062], and at least one of CO2, CO, N2O, NO, or NO2 [para. 0062].
Here, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the polymer removal gas mixture (i.e., H2 and N2), of Rui [para. 0067], to further include an inert gas and N2O or NO2, of Rui [para. 0062] in order to form hydroxyl radicals which further aid in removing etch by-products from the substrate (as to N2O or NO2) [para. 0062], and to enhance radical generation (as to the inert gas).
As to claim 5, Rui discloses the method, as recited in claim 1, wherein the stripping gas is halogen free [para. 0062-63; para. 0065; para. 0067].
As to claim 6, Rui discloses the method for processing a stack with at least one silicon nitride containing layer [para. 0059, “material layer that may be disposed on the substrate include a dielectric layer, such as a SiOC, SiO.sub.2 or a SiCN, SiC or SiN layer”, “the substrate may have multiple layers, e.g., a film stack, utilized to form different patterns and/or features”] on a wafer with a bevel [para. 0061], comprising:
etching at least one feature in the at least one silicon nitride containing layer [para. 0055; para. 0059], wherein the etching the at least one feature forms a polymer containing sidewall film in the at least one feature and a polymer containing deposition layer on a backside of the bevel of the wafer [para. 0061], wherein the etching is provided in a etch chamber with a vacuum [para. 0049-50];
moving the wafer from the etch chamber to a stripping chamber without breaking the vacuum [para. 0049-54];
stripping the polymer containing sidewall film and the polymer containing deposition layer [para. 0061], comprising the steps of:
forming a plasma from a stripping gas [para. 0062-63; para. 0065; para. 0067], the stripping gas comprising:
a hydrogen (H2) containing gas [Id.]; and
at least one of CO2, CO, N2O, NO, or NO2 [Id.; Obvious to include, see below],
wherein the plasma creates radicals from the stripping gas [Id.]; and
exposing the wafer to the radicals, wherein the radicals remove the polymer containing sidewall film and the polymer containing deposition layer [para. 0062, “remove the polymer residuals, photoresist layer, if any, and etch by-products from the substrate 110”].
Rui fails to explicitly disclose an embodiment of the stripping gas comprising a hydrogen containing gas and at least one of CO2, CO, N2O, NO, or NO2
However, Rui discloses the combination hydrogen-containing gas and nitrogen containing gases form highly reactive radicals to remove polymer residuals and etch by-products from the substrate [para. 0062], as follows in pertinent part:
“The remote plasma source 154 of the processing chamber 100 supplied active reactant, such as hydrogen and/or nitrogen containing gases, to the processing chamber 100 to assist removal of polymer residuals, photoresist layer and etch by-products from the substrate 110. As hydrogen species (H.sup.-, H*, H.sup.+), hydroxyl radical (--OH), nitrogen radical, and/or N--H radical are highly reactive radicals to polymers, upon supplied dissociated hydrogen, nitrogen or hydroxyl species into the processing chamber 100, the reactive species are actively reacted with the polymers, forming volatile compounds, readily pumping and outgassing the volatile compounds out of the processing chamber 100. The gas mixture may include an oxygen-containing gas, such as O.sub.2, O.sub.3, water vapor (H.sub.2O), a hydrogen-containing gas, such as H.sub.2, water vapor (H.sub.2O), NH.sub.3, nitrogen containing gas, such as N.sub.2, N.sub.2O, NH.sub.3, NO.sub.2, and the like, or an inert gas, such as a nitrogen gas (N.sub.2), argon (Ar), helium (He), and the like.” [para. 0062].
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the polymer removal gas mixture, of Rui, to include hydrogen (H2) and N.sub.2, N.sub.2O, and/or NO.sub.2, because hydrogen-containing gas and nitrogen containing gases form highly reactive radicals to remove polymer residuals and etch by-products from the substrate, as taught by Rui [para. 0062].
As to claim 7, modified Rui discloses the method, as recited in claim 6, wherein the H2 containing gas is a forming gas comprising:
H2 [para. 0067]; and
N2 [para. 0067],
wherein the forming gas is 0.1% to 4% H2 [para. 0067, “H.sub.2 is supplied at a flow rate between about 50 sccm and about 500 sccm”, “N.sub.2 gas is supplied at a flow rate between about 200 sccm and about 2000 sccm”, which converts to about 2.4% to 71% H2, overlapping and supporting a prima facie case of obviousness over the claimed range].
As to claim 8, modified Rui discloses the method, as recited in claim 7, wherein the stripping gas consists essentially of the forming gas [para. 0067] and at least one of CO2, CO, N2O, NO, or NO2 [para. 0062, “N2O… NO2”].
Here, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the polymer removal gas mixture (i.e., H2 and N2), of Rui [para. 0067], to further include N2O or NO2, of Rui [para. 0062] in order to form hydroxyl radicals which further aid in removing etch by-products from the substrate [para. 0062], with predictable results.
Furthermore, choosing from a finite number of identified, predictable solutions, with a reasonable expectation for success, is likely to be obvious to a person if ordinary skill in the art. See MPEP § 2143, E.
As to claim 9, modified Rui discloses the method, as recited in claim 7, wherein the stripping gas consists essentially of the forming gas, at least one inert gas [para. 0062], and at least one of CO2, CO, N2O, NO, or NO2 [para. 0062].
Here, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the polymer removal gas mixture (i.e., H2 and N2), of Rui [para. 0067], to further include an inert gas and N2O or NO2, of Rui [para. 0062] in order to form hydroxyl radicals which further aid in removing etch by-products from the substrate (as to N2O or NO2) [para. 0062], and to enhance radical generation (as to the inert gas), with predictable results.
Furthermore, choosing from a finite number of identified, predictable solutions, with a reasonable expectation for success, is likely to be obvious to a person if ordinary skill in the art. See MPEP § 2143, E.
As to claim 10, modified Rui discloses the method, as recited in claim 7, wherein the stripping gas is halogen free [para. 0062-63; para. 0065; para. 0067].
As to claim 12, modified Rui discloses the method, as recited in claim 6, wherein the polymer containing deposition layer and the polymer containing sidewall film comprises a fluoropolymer [para. 0060, “wherein the material layer disposed on the substrate 110 is a silicon nitride (SiN), the gas mixture including at least one of CH.sub.2F.sub.2, CHF.sub.3, N.sub.2 and Ar may be used.”]
As to claim 14, Rui discloses a method for stripping a polymer containing sidewall film from etch features and a polymer containing deposition layer from a backside of a bevel of a wafer [para. 0061] with a stack with at least one silicon nitride containing layer [para. 0059, “material layer that may be disposed on the substrate include a dielectric layer, such as a SiOC, SiO.sub.2 or a SiCN, SiC or SiN layer”, “the substrate may have multiple layers, e.g., a film stack, utilized to form different patterns and/or features”], comprising:
forming a plasma from a stripping gas [para. 0062-63; para. 0065; para. 0067], the stripping gas comprising:
at least one of CO2, CO, N2O, NO, or NO2 [Id.], wherein the plasma creates radicals from the stripping gas [Id.]; and
exposing the wafer to the radicals, wherein the radicals remove the polymer containing sidewall film and the polymer containing deposition layer [para. 0062, “remove the polymer residuals, photoresist layer, if any, and etch by-products from the substrate 110”].
Rui fails to explicitly disclose a specific embodiment of the stripping gas comprising at least one of CO2, CO, N2O, NO, or NO2 [para. 0062-63; para. 0065; para. 0067].
However, Rui discloses the combination hydrogen-containing gas and nitrogen containing gases form highly reactive radicals to remove polymer residuals and etch by-products from the substrate [para. 0062], as follows in pertinent part:
“The remote plasma source 154 of the processing chamber 100 supplied active reactant, such as hydrogen and/or nitrogen containing gases, to the processing chamber 100 to assist removal of polymer residuals, photoresist layer and etch by-products from the substrate 110. As hydrogen species (H.sup.-, H*, H.sup.+), hydroxyl radical (--OH), nitrogen radical, and/or N--H radical are highly reactive radicals to polymers, upon supplied dissociated hydrogen, nitrogen or hydroxyl species into the processing chamber 100, the reactive species are actively reacted with the polymers, forming volatile compounds, readily pumping and outgassing the volatile compounds out of the processing chamber 100. The gas mixture may include an oxygen-containing gas, such as O.sub.2, O.sub.3, water vapor (H.sub.2O), a hydrogen-containing gas, such as H.sub.2, water vapor (H.sub.2O), NH.sub.3, nitrogen containing gas, such as N.sub.2, N.sub.2O, NH.sub.3, NO.sub.2, and the like, or an inert gas, such as a nitrogen gas (N.sub.2), argon (Ar), helium (He), and the like.” [para. 0062]
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the polymer removal gas mixture, of Rui, to include N.sub.2, N.sub.2O, and/or NO.sub.2, because hydrogen-containing gas and nitrogen containing gases form highly reactive radicals to remove polymer residuals and etch by-products from the substrate, as taught by Rui [para. 0062].
As to claim 15, modified Rui discloses the method, as recited in claim 14, but fails to explicitly disclose:
wherein the stripping gas consists essentially of at least one of CO2, CO, N2O, NO, or NO2.
However, since Rui teaches that nitrogen radicals are highly reactive radicals to polymers [para. 0062], and that N.sub.2O and NO.sub.2, are effective nitrogen radical sources [para. 0062], it would have been obvious to try removing polymers and etching by-products from the surface of the wafer, bevel, and backside of the wafer [para. 0061] using a polymer removal gas mixture consisting essentially of N.sub.2O or NO.sub.2, because they are suitable nitrogen radical sources for producing highly reactive nitrogen radical to remove polymers, as taught by Rui [para. 0062], with predictable results.
Furthermore, choosing from a finite number of identified, predictable solutions, with a reasonable expectation for success, is likely to be obvious to a person if ordinary skill in the art. See MPEP § 2143, E.
As to claim 16, modified Rui discloses the method, as recited in claim 14, but fails to explicitly disclose:
wherein the stripping gas consists essentially of at least one inert gas, and at least one of CO2, CO, N2O, NO, or NO2.
See the rejection of claim 15, above, as to why it would be obvious to try using a polymer removal gas mixture consisting essentially of N.sub.2O or NO.sub. Furthermore, as to including an inert gas, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the polymer removal gas consisting essentially of N.sub.2O or NO.sub, of Rui, to further include an inert gas, of Rui [para. 0062] in order to enhance radical generation.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Rui et al. (US 20090277874 A1), as applied to claims 1-10, 12, and 14-16 above, and further in view of Cheung et al. (US 20140120733 A1).
As to claim 11, modified Rui discloses the method, as recited in claim 6, but fails to explicitly disclose:
wherein the stripping the polymer containing sidewall film and the polymer containing deposition layer is performed at a temperature in a range of 20° C to 500° C.
However, Cheung teaches a method of stripping a photoresist etch process residue [Abstract; claim 1] utilizing a plasma comprising hydrogen, or hydrogen and carbon dioxide, and maintaining the temperature of the wafer at a low temperature, i.e., less than 200 degrees C, or less than 60 degrees C [para. 0044], in order to prevent damage to low-k dielectric films [para. 0036].
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of stripping photoresist and etch residue, of Rui, to include maintaining the wafer temperature to less than 200 degrees C, of Cheung, in order to prevent damage to low-k dielectric films, as taught by Cheung [para. 0036].
Allowable Subject Matter
Claim 13 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
As to claim 13, prior art of record fails to teach or suggest the feature of “wherein the polymer containing deposition layer further comprises an ammonia salt.” in conjunction with limitations of claim 12 and independent claim 6.
Conclusion
THIS ACTION IS MADE FINAL. 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 CHRISTOPHER M REMAVEGE whose telephone number is (571)270-5511. The examiner can normally be reached Monday-Friday 10:00 AM - 3:30 PM.
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/CHRISTOPHER REMAVEGE/Examiner, Art Unit 1713
/BINH X TRAN/Primary Examiner, Art Unit 1713
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